See discussions, stats, and author profiles for this publication at: https://www.researchgate.net/publication/287490830 The Design and Construction of an Electric Bicycle. Thesis · April 2015 DOI: 10.13140/RG.2.1.3999.4968 READS 986 1 author: Olakunle Alao Covenant University Ota Ogun State, Nigeria 4 PUBLICATIONS 0 CITATIONS SEE PROFILE All in-text references underlined in blue are linked to publications on ResearchGate, letting you access and read them immediately. Available from: Olakunle Alao Retrieved on: 21 August 2016 THE DESIGN AND CONSTRUCTION OF AN ELECTRIC BICYCLE BY ALAO OLAKUNLE OLUWATOSIN 10CK011233 A PROJECT SUMITTED TO THE DEPARTMENT OF ELECTRICAL AND INFORMATION ENGINEERING, COLLEGE OF ENGINEERING IN PARTIAL FULFILLMENT OF THE REQUIREMENTS FOR THE AWARD OF A BACHELOR OF ENGINEERING DEGREE IN ELECTRICAL AND ELECTRONICS ENGINEERING SUPERVISOR: PROF. AWOSOPE C.O.A APRIL, 2015 DECLARATION I hereby declare that the work reported in this project was carried out in the Department of Electrical and Information Engineering, Covenant University, under the supervision of Prof. C.O.A Awosope. I also solemnly declare that to the best of my knowledge, no part of this report has been submitted here or elsewhere in a previous application for the award of a degree. All sources of knowledge used have been duly acknowledged. ………………………………………………………………. ALAO OLAKUNLE OLUWATOSIN (10CK011233) ……..A Awosope Date Sign: ……………………… …………. (Electrical and Electronics Engineering) degree of Covenant University and is approved for its contribution to knowledge and literary presentation.E Idachaba External Examiner: …………. meets the requirements and regulations governing the award of the Bachelor of engineering. Date …………..O. Name: Head of Department: Sign: ……………………… Name: Dr F.Eng. Supervisor: Internal Examiner: Sign: ……………………… Name: Prof C.CERTIFICATION This is to certify that the Project titled “Design and Construction of an Electric Bicycle” by Alao Olakunle Oluwatosin. B..……..……. Sign: ……………………… Name: Date ………….……. Date . amen.DEDICATION This work is dedicated firstly to God Almighty. They have really been a pillar of support in my life and may God bless them abundantly. have afforded me with the opportunity in making this project a reality. through their immeasurable love and care. my Parents who. . the first and greatest engineer ever. A Awosope for his guidance. through their several inputs in one way or another have made this project a dream come true. Colonel and Mrs. . bolting e. I am grateful to my Parents. I am also grateful to my project supervisor. meticulous follow up at the end of each chapter and endless encouragement during my project work. I am grateful to all the technicians that were involved in the project most especially in the hardware coupling as regards welding. Kayode and Kolade who. Shelter Orok and all of my friends and colleagues who have contributed to this project in one way or another.ACKNOWLEDGEMENT I am most grateful to Almighty God for the grace He has given me to work on this Project. support. a hearty appreciation goes to Kenechukwu Ezenwa.c Finally. and to the Management of Covenant University for establishing a safe and conducive learning environment through the help of God.O. Prof C.t. Esther Alao for their financial and moral support and to my Siblings. The rate of improvements in technologies is at an exponential level despite that the electric bicycle is a concept that has been very feasible for years but has not been fully explored.ABSTRACT The Increasing demand for non-polluting mechanized transportation has increased the interest in the use of electric power for personal transportation and also reduced reliance on automobiles. The system design is based on mechanically coupling a dc motor as the primary power source to drive the bicycle and electrically wiring the motor together with a dc rechargeable battery and applying a programmed micro-controller as a control mechanism for effective and efficient transmission from the source to the motor. A low cost alternative to an automobile is a bicycle. . The human electric bicycle is designed to provide electromagnetic propulsions to a bicycle therefore relieving the user of having to produce the energy required to run the bicycle. LIST OF ABBREVIATIONS PM – Permanent Magnet MOSFET – Metal-Oxide Semi-conductor Field Effect Transistor EVB – Electric Vehicle Battery GND – Ground OSC – Oscillator PWM – Pulse Width Modulation IC – Integrated Circuit DC – Direct Current ESC – Electronic Speed Control E-Bike – Electric Bicycle IGBT – Insulated Gate Bi-polar transistor . LIST OF SYMBOLS µ .Voltage s – Seconds f – Farads .Kilo Hz.Nano m .Hertz A .milli K.Micro n.Amperes V. dumping increasing amounts of carbon dioxide and other climate-altering greenhouse gases into the atmosphere. though air quality alone is not a sufficient justification to mandate electric bicycles. Much less oil would be needed because only a tiny proportion of electricity is generated from oil.1 THE PROBLEM DEFINITION The world‟s car usage is booming. Cars are polluting the environment. The reason is that mainly because gasoline cars have benefited from a century of intensive development. It contains a strong motor and enough battery power that just requires charging to help in hill climbing. Electric vehicles cost more and perform worse than their gasoline counterparts. The primary premise for the Universities‟ support of the electric-powered over the petrol powered has been towards improving air quality. electric cars have been virtually ignored for several years. These include the dramatic reduction in oil consumption that its widespread use would bring about. The alarming reality is that the automobile usage is beginning to grow at a much faster rate than the . An Electric bicycle would. 1. generate greater motoring speeds and provide completely free electric transportation. The single biggest advantage of electric bicycle is that it is cost effective as it mainly only entails construction cost as running cost would only require the charging of the battery.CHAPTER ONE INTRODUCTION The electric bicycle is an electrical-assisted device that is designed to provide the electromagnetic propulsions to an existing bicycle therefore relieving the user of producing the energy required to run the bicycle. and consuming vast quantities of petroleum. however offer other strong benefits that are ignored by the marketplace. The other major non-market benefit would be lower greenhouse gas emissions. Even today. gasoline cars profit from billions of dollars of research every year while electric vehicles receive a tiny fraction of that amount of money. I have therefore come to a conclusion that an electric bicycle would be Eco-Friendly to the environment and reduce dependency on automobiles and could even encourage the technology on electric transport and will save our world in its way from Global Warming by reducing the CO gases that are usually emitted from automobiles which cause air pollution and are even harmful to the health. exceeding 20 cars per 100 people. with saturation nowhere in sight. Its importance would include The elimination of fuel consumption by vehicle users when going on a short distance like running errands. In driving the Chancellor‟s vision of 1 of 10 in 10 by year 2022 wherein two saloon cars and a tri-cycle have already been developed by the Covenant University Electric Automobile Research Clusters development on what was called the Covenant University Integrated Dual Engine Automobile System (CU IDEA). The problem to be solved is that of increasing the range of a human-powered bicycle by equipping it with an electric motor running off a lithium ion battery thereby reducing the dependency on automobiles. 1. overtime 3 billion vehicles could be in operation by the year 2050. Reuse and Recycle) during SIWES program. It‟s effectiveness over a wide range of people and the removal of the burden of the pedaling mechanism typical of normal bicycles.human population. This project is a means of providing an alternative for short journeys and also as a recreational facility for persons of all backgrounds and ages.2 MOTIVATION My main motivation of considering this project is that after the thorough study and analysis of being EcoFriendly (Reduce. . I also observed that there is a very large population of vehicles and not enough road infrastructures to cater for them. I have arrived at the idea of an electric bicycle which would be envisaged as more cost effective as the products listed above. If present trends continue. motor and constructing a speed controlling circuitry to ensure proper travel speed control during the operation of the bicycle. The mechanical coupling includes the proper welding and arrangements of all these components especially the motor and batteries on the framework of the bicycle.1. These are The electrical system design stage The mechanical coupling stage The electrical system design stage would include wiring the battery. To accomplish this aim. the electric bicycle will be segmented into two (2) stages.3 AIM AND OBJECTIVES The aim of this project is to incorporate an electromechanical system that would help in propelling a bicycle. This would ensure that it retains a steady standing frame and maintain its balance when in motion. .4 METHODOLOGY In actualizing the objective of this project above. the following specific objectives will be achieved: Simplicity in operation Effective speed control Embedded on an existing bicycle Reasonable power transmission efficiency Cost efficient in terms of operation Would ensure air quality 1. BATTERY Fig 1. aims and objectives of the study including the methodology which would be used in the implementation. The third chapter will discuss the systems design. classification and comparison to prior research studies. The second chapter will present the critical analysis of the literature or a segment of the body of knowledge through summary. this would explain the several design processes that would be used in the implementation of the project. . and the theoretical articles in the study. It also discusses the motivation. reviews of literature.5 REPORT ORGANIZATION This project contains five (5) chapters described as follows: The first chapter includes the introduction and the problem definition of the implementation of the design and construction of an electric bicycle.1 Block diagram of the MOTOR CONTROLLER CIRCUITRY BICYCLE WHEEL ROTATION ELECTRIC MOTOR CHAIN AND SPROCKET Electric bicycle construction process 1. The fifth chapter.The fourth chapter will contain the system implementation and Testing. would contain the summary. achievement. recommendation and conclusion. which is the concluding part of the study. this would explain the actual implementation of the project making use of all the processes to achieve the purpose of the design and also the testing of the project with real life values. . there were no gears and the motor could draw up to 100 amperes from a 10-volt battery. Hosea W. invented an electric bicycle (U. patents.S. On 31 December 1895. Libbey of Boston. The information from this review assisted in situating the project in its present context. was granted U. It wasn‟t much longer than that in which other improvements were made to the electric motor itself which proved significant. One of the first rear wheel electric drive was implemented by using a belt along the outside of the bike. The motor was designed within the hub of the crank set axle. electric bicycles were documented within various U. 2. Patent 596.CHAPTER TWO INTRODUCTION As seen from Chapter 1.1 HISTORY OF THE ELECTRIC BICYCLE Electric bicycle is a bicycle with an electric motor attached to the rear wheel of the bike which generally assists the rider while he or she is peddling. This model was later reinvented and imitated in the late 1990s by Giant Lafree e-bikes. . This chapter entails the theoretical background and concepts necessary for the proper understanding of the scope of the work carried out in this project and from this to better the design and construction of the proposed Bicycle. In 1897. Usually. Ogden Bolton Jr. These batteries are usually rechargeable by plugging them into a regular household outlet and the batteries are usually stored in a charger when doing so.S. internet write-ups and samples of existing and related project. the electric bicycle is not a new technology in engineering but has only sought better approaches.271 for a battery-powered bicycle with a 6-pole brush and commutator direct current (DC) hub motor mounted in the rear wheel.S. Patent 552. electric bicycles get their power to drive and run the electric motor from energy stored in electric batteries that are located somewhere within the electric bicycle.272) that was propelled by a “double electric motor”. Sometime around the year 1898. It comes from studies of various academic texts. which provides the range of 25 to 30 miles (40 to 48 km) at a speed of around 20 km/h. Patent 3. By 2007. it was not until the 1990s when massive changes occurred in electric motor technology as well as battery technology. Despite these improvements. with his U. A typical unit requires 8 hours to charge the battery. Today. the bicycle itself has been a principal mode of transportation that is very cheap and easy to use.S.S. e-bikes were thought to make up 10 to 20 percent of all two-wheeled vehicles on the streets of many major Chinese cities. 2. in general there is an increase in range and speed with the latter battery types. was patented by Mathew J. Patent 627. and/or Li-ion batteries. connected through a series of gears. electric bicycles being much cheaper and pollution free are being used in place of fossil fuel. “and power-assisted bicycle” were commonly used to refer to ebikes. the 1899 U. Wood‟s device used 4-fractional horsepower motors.2 REVIEWS WITH REFERENCE TO EXISTING WORKS . "pedelec".066 by John Schnepf depicted a rear-wheel friction “roller-wheel” style drive electric bicycle. “pedal-assisted”.431. In many countries such as India for example. Wood Jr. Some of the less expensive e-bikes used bulky lead-acid batteries. The term "electric motorbike" or "e-motorbike" refers to more powerful models that attain up to 80 km/h (50 mph). which offered lighter. Performance varies. Now.By 1898. Schnepf's invention was later re-examined and expanded in 1969 by G. a rear-wheel drive electric bicycle. whereas newer models generally used NiMH. Much of this success is due to the fact that the Asian market has been much more active due to the growing affluence in these countries as well as the need for cheaper transportation and less dependence on fossil fuels. there are literally hundreds of electric bicycles on the market and in the last several years.A. the boom of electric bikes has been phenomenal. the terms “e-bike”.994. “power bike”. denser capacity batteries. By 2001. Also. which used a driving belt along the outside edge of the wheel. however. Since the year 2005. NiCd. the electric bike motor as well as the batteries has gotten much more advanced and more capable. Steffens. This current reversal charges the battery. can do so. powered by a 12-volt battery. College of Engineering and Computer Science. The system consisted of three source of power: the human effort of the rider peddling the bicycle. All the components used for obtaining the goal of the project were small enough to fit on the bicycle. The goal of the project was designing and building an electric bicycle. about 10 percent of the energy used combustion engine vehicles during idling. This goal was attained by adding features designed to minimize the power consumption of the system. electric motor running off a 12-volt lead-acid battery. so that one can operate the bicycle at a preset speed (cruise control). First. local storage in batteries and conversion of electric power to mechanical motion is estimated to be approximately 50%. Those who would otherwise not use the bicycle to move around the city. electric vehicles consume no energy during idling.2. The constant speed operation will also provide a sense of comfort.1 ELECTRIC ASSISTED BICYCLE The project was named “Electric Assisted Bicycle” and involved a team consisting of Joe LaPointe and Gregory Huh with each researcher assigned unique tasks throughout the design and implementation stage. University of Michigan-Dearborn. Their major motivation was its energy efficiency advantage. confident that there will be power assistance when they grow tired. The researchers designed an electric assisted bicycle that extended the range of a typical rider. transmission and distribution. while combustion engine vehicles are 15 to 25 percent efficient. with an operating range between 28 to 33 miles. Those who ride the bicycle for exercise can do so either by disabling the electric assistance or by exerting more effort to generate electric power and charge the battery. the overall system efficiency taking into account the production of electric power. This was due to several factors. and a solar panel that can charge the battery when there is adequate sunlight. . and thus provides regeneration not only when braking but as well as when going downhill. or when facing an uphill climb. The project was a university project and was funded by the Center for Engineering Education and Practice. The power module was controlled by a microprocessor. The power control module on the motor will reverse the current in the motor if the speed of the bicycle is more than the desired speed. especially when coming down steep slopes. or when the rider pedals harder than the set speed. The final system has features that will appeal to a broad spectrum of users. Secondly.2. The first feature was to add pulse width modulation. The advantage of pulse width modulation over the use of adding gears to the system is the fact that with gears torque is gained, but distance efficiency is lost. Pulse width modulation allows the motor to operate at a variety of speeds. In order to obtain the pulse width modulation, a microprocessor can be used to trigger the motor. Since the microprocessor puts out a 5-volt signal at 2 mA, and the motor runs off of 12 volts at a current of 20A, a motor controller must be obtained to handle the voltage and current specifications. To control the speed of a D.C. motor, a variable voltage D.C. power source is needed. However, if a 12-V motor was taken and energized, it will start to speed up: motors do not respond immediately so it will take a small time to reach full speed. If the power is switched off sometime before the motor reaches full speed, then the motor will start to slow down. If the power is switched on and off quickly enough, the motor will run at some speed part way between zero and full speed, this is exactly what a p.w.m. controller does. If the motor is connected with one end to the battery positive and the other end to battery negative via a switch (MOSFET, power transistor or similar) then if the MOSFET is on for a short period and off for a long period as in A, the motor will only rotate slowly. At B, the switch is on 50% and off 50%. At C, the motor is on for most of the time and only off a short while, so the speed is near maximum. In a practical low voltage controller, the switch opens and closes at a frequency of 20 kHz. This is far too fast for the motor to even realize it is being switched on and off: it thinks it is being fed from a pure D.C. voltage. It is also a frequency above the audible range so any noise emitted by the motor will be inaudible. It is also slow enough that MOSFETs can easily switch on at this frequency. However, the motor has inductance. Inductance does not like changes in Fig 2.1 MOSFET operation current. When implement ing the system with a microprocessor, an RC circuit will be used; it as a buffer between the microprocessor and the controller circuit. 2.2.2 IMPROVED AND EFFICIENT ELECTRIC BICYCLE SYSTEM The project work was named “An improved and efficient Electric Bicycle System with the power of real time information sharing” and involved a team consisting of Chetan Mahadik, Sumit Mahindrakar and Prof. Jayashree Deka. The work was published in the multidisciplinary journal of research in engineering and technology from K.J College of Engineering Pune, India. Many different components were considered in the design of the electric bicycle with several additional features. The power source for the system was given by a dry cell battery. The output of the dry cell battery was 48-V. There were multiple forms of charging source considered such as AC voltage through an outlet, solar energy and mechanical pedal charging system. The source of battery charging was through the photovoltaic solar panel which is light in weight. The solar panel output was 12V and 20 watt. A mechanical pedal charging system was used and dynamo used for the charging system. A dynamo is an electrical generator that produces direct current with the use of a pedal. A dry cell battery block was connected with a controller block. The controller was used to regulate the amount of applied power on brushless DC motor. Also, there are many functions for this controller like over current protection, under voltage protection and also a throttle was used to control the speed of the brushless dc motor. These functions were beneficial to the system and also provided a solution to any troubleshooting and damages that occurred. The following were considered as the major materials: (i) Brushless DC (BLDC) motor: This is a synchronous motor consisting of armature windings on the stator and permanent magnets on the rotor. The stator of a BLDC motor consists of stacked steel laminations with windings placed in the slots and these stator winding can be arranged in two patterns i.e. a star pattern or delta pattern. The major difference between the two patterns is that the star pattern gives high torque at low RPM and the delta pattern gives low torque at low RPM. There are many advantages of BLDC motor such as better speed versus torque characteristics, high dynamic response, high efficiency, long operating life, noiseless operation, higher speed ranges. The Hall sensors are embedded into the stationary part of the motor. Here, hall sensors are connected with hall sensor magnet to detect the position of rotor. In BLDC motors, the phase windings are distributed in trapezoidal fashion in order to generate the trapezoidal waveform. The commutation technique generally used is trapezoidal commutation where only two phases will be conducting at any given point of time. Typically BLDC motors have three-phase windings that are wound in star or delta fashion and need a threephase inverter bridge for the electronic commutation. The brushless motors are generally controlled using a three-phase power semiconductor bridge. The motor requires a rotor position sensor for starting and for providing proper commutation sequence to turn on the power devices in the inverter bridge. (ii) PIC Controller: The motor controller technique used to control the electric bicycle system was a PIC16F72 controller. There are different functions of this controller such as under voltage protection, over current protection, power supply control, also to drive and control the Brushless dc motor. Different signals were transmitted to the pins of the PIC controller to drive and control the brushless dc motor, such as current detection signal, motor speed control signal, capacity detection system. The PIC16F72 controller has 28 pins, 22 I/O pins that are user configurable on a pin-to-pin basis. There are 35 numbers of instructions in this PIC controller with the operating frequency set at 20 MHz. Also, in this controller were three I/O ports such as PORTA, PORTB and PORTC and three Timers: Timer0, Timer1 and Timer2. In the pin diagram, RA1, RA4 and RA5 pins were used for speed control and current detection signal. The current detection signals were used If sunlight is absorbed by silicon then electrons would be excited. The mechanical energy produced by the rotation is thus converted into electrical current in the coil.here because of any heavy current situation such as when the electric bicycle is running on heavy load thereby causing an increase in the current of the motor which will cause damages to the winding and components of the motor. In this bicycle a 20-W solar panel is used and is connected to a 12-V battery this configuration was used for charging the battery. It consists of a powerful magnet and pole on which its coil rotates. If the bicycle is running then the commutator is rotating and therefore generates the power. The solar panel converts energy from sunlight directly into electricity through utilization of photovoltaic effect. if electrons are excited they dissipate the energy and it travels through the cell until it reaches an electron. Also required was the current detection signal for controlling the current. the dynamo was placed on the front wheel of the bicycle and dynamo commutator was connected at the front wheel of the bicycle. (iii) Dynamo: A dynamo is an electrical generator that produces power with the use of a commutator. In the dynamo. A dynamo is a simple generator that is used to convert mechanical motion into electrical motion with the help of a magnet. These electrons are only allowed to move in a single direction. This solar panel module was in a series configuration to provide an additional voltage. so it converts mechanical rotation into an electric current on the basis of Faraday‟s law of induction. (iv) Solar panel: Here we also use solar panel for generating power. which affects the normal running operation of the bicycle. photons in sunlight hit the solar panel and are absorbed by silicon material. The rotating coil cuts the line of magnetic force. The solar panel is electrically connected as a module with sheet of glass on top to allow light to pass. thereby inducing current to pass through the wire. . under voltage protection was required to avoid low voltage supply. In solar panel. we use a rotating coil of wire and magnet. In this electric bicycle. 5 Amp-hr Lithium Iron Phosphate (LiFePO4) battery to achieve the final powerful design. the high inrush current from the batteries fused the line regulators in this design. and the array voltage would fall from 30 to 7 Volts under the rated 10 Amp load. In addition.2-V.3 THE DESIGN. Originally. The controller was based on an MSP430 microcontroller. they overheated at the rated 3 Amp charge. SIMULATION AND CONSTRUCTION OF AN ELECTRIC BICYCLE The project was an undergraduate independent study project by Ben Rogowitz and supervised by Dr. Department of Electrical Engineering and Computer Science. Allison Kipple. and then converted to a high speed Pulse Width Modulation (PWM) controller. A generic 10Amp diode. After a couple of months. a buck converter (Texas Instruments TL2575HV-15. There were three iterations for the battery component in this design. 600-V. an MSP430F2012 microcontroller was chosen as the key component of the motor control circuit. primarily due to previous experience with the device. the batteries did not meet their manufacturer‟s ratings. Therefore. two MOSFETs (model #IRF3710 with 100-V. Two packs of 25 cells were soldered together (after 6 hours) to create a 30-V input. 75-A ). and the MOSFETS were replaced by IGBTs (Mouser #40N60A4. However. the batteries could no longer hold a charge. Unfortunately. The microcontroller was then replaced by a high speed PWM Integrated Circuit (Texas Instruments model #UC3823). two battery packs were composed of inexpensive NiMH batteries (1.2. 3-A charge rate and 30-A discharge rate). 10 A-hr per cell. Nothern Arizona University In this project a buck converter was selected due to its high efficiency. along with accessories to integrate the motor with the existing bicycle.2. A few supporting circuit elements were also updated. Initially. 57-Amp ratings). a 750-W scooter motor with an appropriate chain sprocket was selected. and line regulators were also used within this circuit. subsequently destroying the microcontroller. 60-V) with an integrated switch was used in place of the line regulator to provide a constant 15-V for the controller and other circuit components. . The customary 10 Amp-hr Nickel-Metal Hydride (NiMH) battery was replaced with a 13. However. when the resistance would increase.6-V.5 A-hr. but the simulation did not predict this. the failed IGBTs were replaced. This pack performed well. the legality of road use is left to states and provinces. Although the simulation did a reasonable job of modeling the real world. Federal regulations. even though the simulations were educational and provided useful information. This is actually a very rational and reasonable law and it promotes the development and the usage of good electric bicycles as it enables users of all ages to fully utilize and enjoy the benefits of the electric bicycle with safety precautions in mind. 52V. there is a range of classifications . 60-A current limited.A second battery pack was created with 8. Unfortunately. The motor spins at 50 rpm per volt. confusion still remains regarding the various laws involving electric bicycles. 2. with short circuit protection). Furthermore. A resistance of 0.3 A-hr NiMH batteries. The diodes were then upgraded to ultrafast models (Mouser BYT79X-600-127. trr = 30 ns). 600-V. and the final version has worked well ever since. A MATLAB Simulink model of the electric bicycle‟s final power system design was created. an LiFePO4 battery system was received (13. However. and IGBTs then failed under high voltage. the actual system behaved quite differently. they did not completely represent the physical system.2 Ω and inductance of 200 μH were assumed. 3. and the 36-V / 1800 rpm condition was simulated. now allow up to 20 mph before the electric bicycle will be classified as an unregistered motorcycle. in most countries. the current flowing through the MOSFET closely resembles an impulse response when the device is turned on. Therefore. The simulation also did not account for the rise and fall times of the IGBT when it was operating in a triode region. a diode failed.3 LEGALITY OF ELECTRIC BICYCLES Many countries have enacted electric bicycle laws to regulate the use of electric bicycles. when the limits of the new battery system were tested. In addition. 30-A. and then complicated further by municipal laws and restrictions. This stems from the fact that while some countries have national regulations. holding its voltage with a current draw over 30-Amps. pedal-driven. In other words. general fitness.and terms describing them – "power-assisted bicycle" (Canada) or "power-assisted cycle" (United Kingdom) or “electric pedal-assisted cycles” (European Union) or simply "electric bicycles". A battery powers the motor. both in terms of culture and of advancing modern industrial method. military and police applications. In Nigeria. A bicycle rider is called a cyclist or bicyclist. 2. . They are till today the principal means of transportation in many regions. single-track vehicle. Several components that eventually played a key role in the development of the automobile were initially invented for use in the bicycle including ball bearings. the cyclist on the e-bike needs to give less energy to reach the same speed as the cyclist on a conventional bicycle. one behind the other and usually propelled by pedals connected to the rear wheel by a chain and having handlebars for steering and a saddle like seat. The bicycle‟s invention has had an enormous effect on society. the Ministry of Transport doesn‟t regulate the electric bicycle as the electric bicycle technology is not a common means of transportation yet in Nigeria 2. The major components are a bicycle. having two wheels attached to a frame. courier services and bicycle racing.4. dry cell battery. With the same amount of energy from the cyclist the e-bike has a higher speed compared to a conventional bicycle.1 BICYCLE A bicycle is a human-powered. They also provide a form of recreation and have been adapted for use as children‟s toys. brushless DC motor. pneumatic tires. chaindriven sprocket and tension-spoked wheels.4 THE FEATURES THAT MAKE UP THE ELECTRIC BICYCLE There are many different components in an electric bicycle. motor controller. An electric bicycle (e-bike) is a bike with an electric motor that supports pedalling. Hydraulic hybrid vehicles use hydraulic motors to store energy in form of compressed air. In electric railways. In battery electric and hybrid electric vehicles. where the excess kinetic energy is converted to heat by friction in the brake linings and therefore wasted. 2. which can either be used immediately or stored until needed. the generated electricity is fed back into the supply system.1 REGENERATIVE BRAKING In order to achieve the regenerative braking. The most common form of regenerative brake involves using an electric motor as an electric generator. it is essential that (i) the voltage generated by the machine should exceed the supply voltage and (ii) the voltage should be kept at this value. or mechanically in a rotating flywheel.2. the energy is stored chemically in a battery.4.2 FRICTION-BASED BRAKING This employs the method of applying brake pads to the wheel of the vehicle to restrict the movement or the wheel. This contrasts with conventional braking systems.4.2. This constitutes the mechanism employed for bringing the motion of the bicycle to a stop. . It generates a lot of heat and leads to the wearing and tearing of the brake pads. electrically in a bank of capacitors.2. irrespective of the machine speed A regenerative brake is an energy recovery mechanism which slows down a vehicle or object by converting its kinetic energy into another form.2 VEHICLE BRAKING It is very crucial to discuss the available and possible breaking systems to be applied in the electric bicycle. The two major mechanisms are Regenerative braking Friction-based braking 2.4. For this reason. Therefore. The maximum force available for acceleration is typically much less than this except in the case of extreme high-performance vehicles. friction-based braking is necessary on the other wheels. Physical locking of the rotor is also required to prevent vehicles from rolling down hills. the power required to be dissipated by the braking system under emergency braking conditions may be many times the maximum power delivered under acceleration. Effective regenerative braking can only occur if the battery or capacitors are not fully charged. Under emergency braking. Traction motors sized to handle the drive power may not be able to cope with the extra load and the battery may not be able to accept charge at a sufficiently high . it is desirable that the braking force exerted be the maximum allowed by the friction between the wheels and the surface without slipping. Most road vehicles with regenerative braking only have power on some wheels (as in a two-wheel drive car) and regenerative braking power only applies to such wheels because they are the only wheels linked to the drive motor.4. 2.2. The amount of electrical energy capable of dissipation is limited by either the capacity of the supply system to absorb this energy or on the state of charge of the battery or capacitors. therefore the friction brake is still required in order to bring the vehicle to a complete halt. so in order to provide controlled braking under difficult conditions (such as in wet roads). over the entire speed range from the vehicle's maximum speed down to zero. which can be dangerous if braking performance drops below what is required to stop the vehicle. which make it necessary to be used in conjunction with traditional friction-based braking. The reasons are highlighted below: The friction brake is a necessary back-up in the event of failure of the regenerative brake.3 REGENERATIVE BRAKING WITH FRICTION-BASED BRAKING The regenerative braking has some limitations. it is normal to also incorporate dynamic braking to absorb the excess energy.Friction based-based braking systems are susceptible to „brake fade‟ when used extensively for continuous periods. The regenerative braking effect drops off at lower speeds. The electric bicycle is a hybrid and so it can run electrically and can also be pedaled thereby still retaining the exercise people drive from riding bicycle. 2.rate. . For these reasons.5 CONCLUSION In conclusion. the electric bicycle would be use all over the world because of its numerous advantages. Friction braking is required to dissipate the surplus energy in order to allow an acceptable emergency braking performance. there is typically the need to control the regenerative braking and match the friction and regenerative braking to produce the desired total braking effect. In the near future. this project is designed to improve the ordinary bicycle and make it more efficient. 3 rpm. Hence for speed 1 at 25 rpm. when one of the control button is turned on it switches relay 1 and the second control button when turned on does likewise. The first step that must be taken in design is to accurately and explicitly specify the requirements of the design. 3.65 rpm and for speed 2 at 50 rpm the bicycle will drive at 135. The design task involves the selection of the different components of the electric bicycle with appropriate specifications and the supporting circuit necessary for the smooth operation of the bicycle. The details of these descriptions are well detailed in this chapter. . This then controls the motor using a LED for indication of switching and speed change. All circuit diagrams developed have been comprehensively documented in this chapter. The output voltage value is filtered and smoothened by large capacitors.1 PROJECT PROCEDURE DESCRIPTION 230-V AC is supplied to charge the electric bicycle battery from a 13-A switch socket outlet. The motor is rated at 40 Watts with speed 1 at about 25 rpm and speed 2 at about 50 rpm and the number of teeth for the drive gear is 46 while that for the driven gear is 17.8-V input is regulated by the LM7805 voltage regulator to power the micro-controller. the bicycle will drive at 67. but the micro-controller utilizes 5-V. hence the 13. then regulated by the voltage regulating component (LM317T) to produce a 13. The 230-V AC supply passes through the charging circuit which contains a step-down transformer 230/15-V AC. Two relays are connected to the micro-controller to vary the motor speed.8-V dc.CHAPTER THREE SYSTEM DESIGN AND IMPLEMENTATION INTRODUCTION This Chapter majors in the design considerations before implementation. The battery output supplies the micro-controller which is PIC18F1320. and this is converted to DC by the bridge rectifier (rectification). 05 hp Motor speed (No-Load): 45/65 ± 5RPM Motor speed (Load.8 V dc Output Voltage: 12 V dc MOTOR Motor voltage rating: 12 V dc Frequency: 50 Hz Motor power rating: 40 W/0.2 DESIGN SPECIFICATIONS TRANSFORMER / RECTIFIER CIRCUIT Input voltage: 230 V ac Output voltage: 15 V dc BATTERY Input Voltage: 13. Speed 1): 20/30 ± 5RPM Motor speed (Load. Speed 2): 40/60 ± 5RPM Weight: 2.3.1 kg MICRO-CONTROLLER Input voltage: 5 V OTHER Gear ratio: 1:3 . 1 Block diagram of the system DC MOTOR MECHANICAL ROTATION OUTPUT .Control Technology: PIC18F1320 DC SUPPLY MICROCONTROLLER SPEED CONTROL Fig 3. 13.2 Circuit Diagram .8-V output Fig 3. 3 THE POWER SUPPLY UNIT Power supply is one of the basic requirements for all electronic appliances. Batteries are one form of dc source.1 TRANSFORMATION A transformer is a device that transfers electrical energy from one circuit to another by the use of electromagnetic induction. However.3. they are not large and are free of ripples. a 230-V AC supply from the mains was utilized to provide a 15-V DC output. this was in turn used to power the micro-controller (PIC18F1320) which required only 5 V as its input to control the electric motor rated at 0.8-V DC output (constant output supply) 230-V AC Mains Input Transformer 230/15 V AC Rectifier 15-V pulsating Filtering DC Voltage Regulation 15/13.8 V dc Fig 3.3. frequent replacements are needed due to discharge and they are more expensive than conventional dc power supplies. Most electronic devices require dc power sources to be able to function. It is a static (or stationary) electro-magnetic passive electrical device that works on . alternating voltage conversion to dc voltage is possible and very advantageous since ac power supply is economical to produce. Most importantly.3 Block diagram of the power supply unit 3.8 V by current limiting resistors. The 15-V DC output was regulated to 13. For the execution of this project.05 hp 13. their voltage output is low. or the amount of electrical power being transferred from one winding to another via the magnetic circuit. without modifying its frequency. D1 . D2 and D3 are forward biased.4 V which is as a result of the 2 diodes which are always present at the conduction path of each cycle.2 RECTIFICATION Rectification is the process of converting an alternating ac voltage to a pulsating dc voltage. there is a voltage drop of 1. During the negative half-cycle.the principle of Faraday‟s law of induction by converting electrical energy from one form to another. Step-down transformer: Provides an output voltage that is lower than the input voltage For the execution of this project. In this application of rectification. a step-down transformer was used to step down a 230-V supply to a 15-V supply which is an unregulated and alternating voltage. D3 and D4 are reverse biased. Transformers are capable of either increasing or decreasing the voltage and current levels of their supply. 3. Fig 3. D1 and D4 are forward biased.4 Full wave bridge rectifier In the full-wave rectifier. a full wave bridge of four diodes incorporated into a single electronic was used.4 V is across the rectifier circuit.3. During the positive half of the input voltage cycle. When a voltage greater than 1. There are two types of transformer namely: Step-up transformer: Provides an output voltage that is higher than the input voltage. 01-V .and D4 are forward biased and current starts to flow through D1 to the load and to the ground. then up from the ground through D4 to the lower part of the transformer. Rectification analysis = maximum value of voltage = average value of load voltage = peak value of half wave = root mean square value of the output voltage = 12-v x √2 = = 12 x √2 = 16. D1 and D3 are now reverse biased. This implies D2 and D3 do not allow current to pass through in the opposite direction and thus the diodes behave like a switch.971-V = - = 16. D2 and D3 are reversed biased and thus only negligible leakage current will flow through. thus current flows out of the lower part of the transformer through D2 to the load and then to the ground and also up from the ground to the upper part of the transformer through D4.7) = 15.571-V = (2 x = ) = 9. D2 and D4 are now forward biased. At the opposite half cycle.971-V – (2 x 0. At this stage.913 √2 = 11. 913)^2 (9. and then discharges as it supplies current to the output. 3. For most circuits. Fig 3. The value of the capacitor must be doubled when smoothening half-wave DC. Smoothening is not perfect due to the capacitor voltage reducing a little as it discharges. Selecting a filtering capacitor . Smoothening is performed by an electrolytic capacitor which has a large value connected across the supply to act as a reservoir.3.4 x RMS value). sending current to the output when changing DC (dotted line) and the smoothed DC (solid line). providing a small ripple voltage. a filter circuit is introduced to smoothen the ripple. The capacitor charges rapidly near the peak of the changing DC. Therefore.Allowable ripple factor = √ ( ^2 - ^2) Allowable ripple factor = (√ (11.5 Smoothening Filtering increases extensively the average value of DC voltage to almost the peak value (1. a ripple which of 20% of the supply voltage is acceptable and the equation below gives the required value for the smoothening capacitor. A large capacitor will provide fewer ripples at its output.3 FILTERING This is also known as smoothening and can be defined as the removal of pulsations found in the output voltage.01)^2 – (9.483 The output of the rectifier is a rippled DC which can damage digital circuits.913) = 0. 3.01-s C = (0.20 = 3.5-A t = 0.5 x 0.414 = 23.01) / (3.414 = 16. = 12V x √2 = 12 x 1. It provides the functions of pass element. C=( x t) / ( ) where C = capacitance {in microfarads (µF)} = 0. However the magnitude of the ripple voltage can be further cut down if a capacitor with a larger value is used.3936) = 1473 µF Voltage rating of the capacitor = = x √2 = 16.Allowable ripple factor = 20% of ripple effect.F. where f = 50 Hz Time (t) = 1/2f = 1/(2 x 50) = 0.968 V (no load voltage) = The ripple voltage.4 VOLTAGE REGULATION A voltage regulator is designed to automatically maintain a constant voltage level.3936 V The time interval for charging pulses (T) Ripple frequency = = 2f. voltage reference.968 x 1. 3. and protection from overcurrent in one package. = x Ripple % = 16.01-s = 10 ms Therefore. this would cause a reduction in the on time of the conducting pair of diodes which automatically makes the surge time of the diode excessive.968 x 0.99 V Hence. 24-V capacitor. the best choice practically will be a 100. It may use an . 4 BATTERY UNIT A battery is a device that converts chemical energy directly into electrical energy. usage. depending on the design. 3. and disposal imposed because of concerns over cadmium toxicity Simplified incorporation into products currently using nickel cadmium cells because of the many design similarities between the two chemistries. each voltaic cell consists of two half-cells connected in series by a conductive electrolyte containing cations and anions. 3. For the purpose of this project.8 V to charge the battery and the LM7805 was used to regulate the voltage output from the battery from 12 V to 5 V that was used to power the micro-controller. The voltage regulator has the primary function of keeping the terminal voltage of the DC supply constant when the ac input voltage to the transformer changes or the load varies. Elimination of the constraints on cell manufacture. it may be used to regulate one or more AC or DC voltages.electromechanical mechanism.5 THE MICRO-CONTROLLER UNIT Peripheral Interface Controller or Programmable Intelligent Computer (PIC) is a family of the modified Harvard architecture microcontrollers made by Microchip Technology. The 12-V lead acid battery was selected for the actualization of this project due to its following advantages: Improved energy density (up to 40 percent greater than nickel-cadmium cells) which can be translated into either longer run times from existing batteries or reductions in the space necessary for the battery. It consists of a number of voltaic cells. an IC voltage regulator LM317T was used for voltage regulation at the power supply unit to regulate the voltage from 15 V to 13. . derived from the PIC1650 which was originally developed by General Instrument's Microelectronics Division. or electronic components. depending on the family) which could be extended through banking. The program counter is mapped into the data space and is writable. A small number of fixed-length instructions. All RAM locations function as registers as both source and/or destination of math and other functions. extensive collection of application notes. large user base. and peripheral registers. Their advantages include the following: Small instruction set to learn Reduced Instruction Set Computer (RISC) architecture Built-in oscillator with selectable speeds Easy entry level. wide availability. availability of low cost or free development tools. in-circuit programming plus in-circuit debugging PICKit units available for less than $50 Inexpensive microcontrollers . with one delay cycle on branches and skips. The PIC architecture has the following features: Separate spaces for code and data (Harvard architecture).PICs are popular with both industrial developers and hobbyists alike due to their low cost. One accumulator . A small amount of addressable data space (32. or 256 bytes. or 4-clock cycles in 8-bit models). ALU status flags are mapped into the data space. and serial programming (and re-programming with flash memory) capability. Most instructions are single-cycle (2-clock cycles. Data-space mapped CPU. port. A hardware stack for storing return addresses. 128. LIN. an ICD. data acquisition.5 volts which makes this device ideal for battery managed applications.1 PIC18F1320 MICRO-CONTROLLER This microcontroller has nano-Watt (nW) Technology. . a 2-speed start-up from a reset or sleep mode and a new fail-safe clock monitor that is used to detect an external clock failure. telecom and consumer audio/video applications. which features six enhanced power-managed "software controlled" modes. Addressable Universal Asynchronous Receiver Transmitter (AUSART) and Advanced Low Power Oscillator controls. A/D. while others can use the accumulator only. Selfprogramming. This powerful 10 Million Instruction Per Second MIPS (100 nanosecond instruction execution) yet easy-to-program (only 77 single-word instructions) CMOS FLASH-based 10-bit microcontroller packs Microchip's powerful PIC® architecture into an 18-pin package and is upwards compatible with the PIC16C5X. USART. power consumption as low as 0. All of these features make it ideal for battery powered and power consumption critical applications including instrumentation and monitoring. and Ethernet Availability of processors in DIL package makes them easy to handle for hobby use. 7 channels of 10-bit Analog-to-Digital (A/D) converter. This device also encompasses a new low-current watchdog timer. CAN. PWM. SPI. some instructions can address RAM and/or immediate constants. Their Limitations include the following: One accumulator Register-bank switching is required to access the entire RAM of many devices Operations and registers are not orthogonal. programmable comparators. power conditioning. The PIC18F1220 features a 'C" compiler friendly development environment. capture/compare/PWM functions.1 micro-amps (µA) in standby mode and a wide operating voltage ranging from 2 volts to 5. PIC16CXX and PIC17CXX devices and thus providing a seamless migration path of software code to higher levels of hardware integration. PIC12CXXX.5. 3. environmental monitoring. 128 bytes of EEPROM. USB. Wide range of interfaces including I²C. PSP. 2V .000 erase/write cycle Enhanced FLASH program memory typical . peripherals on .Supports RS-485/RS-232 and LIN 1.1 µA.2 Special Microcontroller Features are .Timer1 Oscillator: 1.Three external interrupt .Four Crystal modes .1. 32 kHz. 2V .RUN: CPU on.Compatible 10-bit.PRI_RUN: 150 µA.Enhanced Capture/ Compare/ PWM (ECCP) module .000.Watchdog Timer: 2.8 x 8 Single-Cycle Hardware Multiplier .Programmable period from 41 ms to 131s .1 µA . up to 13-channel Analog-to-Digital Converter module (A/D) .Single supply 5V In-circuit Serial Programming via two pins .Two-Speed Oscillator Start-up Peripheral Features .High current sink/source 25 mA/25 mA .Self-reprogrammable under software control .100. 1 MHz.In-Circuit Debug (ICD) Oscillators .Its features include: Low-Power Features include the following .000 erase/write cycle Data EEPROM memory .Priority levels for interrupts . 7 PIC18F1320 Outer structure .Fail-Safe Clock Monitor Fig 3..Two external RC modes.8 user-selectable frequencies .Secondary oscillator using Time1@ 32 kHz .6 PIC18F1320 Pinout description Electrical characteristics Maximum output current sunk by any I/O pin = 25mA Minimum output current sourced by any I/O pin = 25mA Fig 3. up to 4 MHz . Q on each conductor to the voltage V between them.3.6 OTHER COMPONENTS UTILIZED 3. but charges and discharges more efficiently. 3. defined as the ratio of charge +/.6.2 CAPACITORS A capacitor.3 SWITCHING CIRCUIT (RELAY) . An ideal capacitor is characterized by a constant capacitance C.6. 3.6. i. which is a passive electronic component.1 RESISTORS A resistor is a two-terminal electronic component that produces a voltage across its terminals that is proportional to the electric current passing through it in accordance with ohm‟s law V=IxR The formula for calculating resistance is given by R = V/I The function of the resistor in both the charging and control/switching circuits is for current limiting.e C = Q/V Large capacitors are used in the battery charging unit for filtering and elimination of pulses. consists of a pair of conductors which are separated by a di-electric. A capacitor has good similarities with a battery. while they are used in the micro-controller unit for the oscillator. 7 V (silicon) = 5 V (from micro-controller) = (collector resistance) V+ = + = + = - .This is the part of the circuit under the control of the micro-controller. 30-mA relay with a coil resistance of 300Ω was used Choosing the base resistor V+ = 12 V (relay voltage from regulated dc supply) = 0. into a pulling mechanical force which operates the electrical contacts within the relay Fig 3.8 Relay Components The 12-V. Electromechanical relays are electro-magnetic devices that convert a magnetic flux generated by the application of a low voltage electrical control signal either AC or DC across the relay terminals. the load is powered and the signal sent to the micro-controller. The function of this circuit is to switch on/off the external load and regulate it to its different speeds. When mains power supply is available. where = collector current = base current = input voltage V+ = supply voltage = collector-emitter voltage = 0-V (at saturation mode) 3. both electrically and physically has been done. high-current Darlington transistor array which consists of seven NPN Darlington pairs that feature high-voltage outputs with common-cathode fly-back diodes for switching inductive loads.6.4 INTEGRATED CIRCUIT (ULN2003) The ULN2003A is a high-voltage. The drivers can be paralleled for higher current capability. even stacking one chip on top of another. Features include 500-mA rated collector current (single output) 50-V output Includes output fly-back diodes Inputs compatible with various types of logic Applications include In driving Relays . it can also be used for interfacing with stepper motor. where the motor requires high ratings which cannot be provided by other interfacing devices. Generally. 6.Light OFF: This would indicate that the motor is on. In this project.Light ON: This would indicate that the motor is off .10 ULN2003 Outer structure 3. The different indicators that were established include . Lamps LED displays Stepper motors Fig 3.5 LIGHT EMITTING DIODE (LED) This is a forward-biased P-N junction that emits light through spontaneous emission by a phenomenon termed “electroluminescence”.9 UNL2003 Pinout diagram Fig 3. a LED was used for the indication of switching and control speed. it can be indicated in either form as below: . the smaller gear usually rotates faster than the larger gear though the larger torques gear is still proportionally greater. When two gears mesh. since the LED used in this project was blue. In transmissions with multiple gear ratios such as bicycles. motorcycles and cars.6. but 4 V for blue and white LEDs) Hence. and often also with that shape on the other gear. The value of the resistor R is obtained using the equation R=( where: )/ I = supply voltage = LED voltage (usually 2 V. so as to prevent damage to the LED. which mesh with another toothed part to transmit torque. in most cases with teeth on the one gear being of identical shape. (ii) Fast Twinkle: This would indicate that the motor is on speed 2. .(i) Slow Twinkle: This would indicate that the motor is on speed 1. with the rotational speeds and the torques of the two gears differing in an inverse relationship. or cogs. When two gears mesh.6 GEAR A gear is a rotating machine part having cut teeth. and one gear is bigger than the other (even though the size of the teeth must match). the term “gear” refers to a gear ratio rather than an actual physical gear. resistor R acted as a current limiting resistor and was connected in series with the LED 3. a mechanical advantage is produced. then =4V I = LED current It is ideal to choose a LED whose current is less than the maximum current allowed. also known as its speed ratio. The speed ratio and mechanical advantage are defined so they yield the same number in an ideal linkage 3.... The gear ratio can be calculated directly from the numbers of teeth on the gears in the gear train.. also known as its mechanical advantage.. is determined by the gear ratio... if the input gear GA has the radius rA and angular velocity ωA . then .2 GEAR TRAINS WITH TWO GEARS The simplest example of a gear train has two gears and that is the type used for the implementation of this project......6. the power output of the output (driven) gear depends on the ratio of the dimensions of the two gears.. is the ratio of the angular velocity of the input gear to the angular velocity of the output gear...6.11 A 76 teeth Gear 3..6.. The input gear will typically be connected to a power source.. Mathematically.. and meshes with output gear GB of radius rB and angular velocity ωB .. In such an example. such as a motor or engine.. The "input gear" (also known as drive gear) transmits power to the "output gear" (also known as driven gear).. The torque ratio of the gear train...(i) .6..1 GEAR RATIO The gear ratio of a gear train.Fig 3... 3 rpm From this deduction. = 135. and number of teeth are equal.8 times faster than the gear attached to the motor (drive gear). .. NA is the number of teeth on the input gear and NB is the number of teeth on the output gear. then the input gear GA must rotate faster than the output gear GB. 3. therefore from equation (iii) above. radii. we have Gear ratio = 50 = 17 46 Hence.8. a 46-teeth gear was used as the drive and a 16-teeth gear as the driven. For the implementation of this project. The following equation is formed: ……………………(ii) This shows that a simple gear train with two gears has the gear ratio R given by ……………….7 CONCLUSION This chapter discussed the system design and processes required for the realization of the project.The number of teeth on a gear is proportional to the radius of its pitch circle. which means that the ratios of the gears' angular velocities.……(iii) This equation shows that if the number of teeth on the output gear GB is larger than the number of teeth on the input gear GA. we can observe that the gear attached to the bicycle (driven gear) would rotate about 2. hence the ratio would be 1:2. Mounting and welding of devices. It introduces the mechanism used in running the bicycle and the testing methods applied.CHAPTER FOUR IMPLEMENTATION AND TESTING INTRODUCTION This Chapter discusses the project implementation.1 SOFTWARE IMPLEMENTATION This entails the coding of the speed and switching control circuit on the PIC18F1320 micro-controller before burning of the codes.1. construction and the various testing methods adopted. . Electrical wiring of the system. 4. 4.1 IMPLEMENTATION The Project construction was divided into the following three (3) main categories: Construction of the speed controller circuit. 2.1.1 MOUNTING AND WELDING OF DEVICES . welding of devices and the electrical wiring of the system. 4.2 HARDWARE IMPLEMENTATION The hard ware implementation of this project entails the mounting.Fig 4.1 Interface of the compiler (mikroC PRO for PIC) 4.1. 3 Mounting of an additional sprocket for motor driving .Prior to construction. Fig 4. a moderately sized bicycle which could withstand the weight of the modules that was to be constructed on it is required.2 Bicycle prior to mounting of electrical features and mechanical coupling Fig 4. 5 Gear connection of the sprocket and motor via a power chain .Fig 4.4 Sprocket Coupling on the back wheel Fig 4. 7 Package for power supply unit.c motor and battery on the bicycle 4.6 Mounting of the d.2 ELECTRICAL WIRING OF THE SYSTEM This involves the electrical wiring of all the battery.1. speed controller and the motor together Fig 4.Fig 4.2. micro-controller unit circuits . c or pulsating d. Tests on units independent of one another were carried out such as the resistance and capacitance values before circuit connection. the battery voltage that should be feeding the micro-controller is to be a little above 6 V dc.2 MICRO-CONTROLLER UNIT TEST Micro-controllers are powered with 5 V dc with their output also at 5 V.1 POWER SUPPLY UNIT TEST The power supply unit consists of a switch. the d. controlling function for every time the control button was pressed.c motor to ensure the required revolutions per minute on no-load. 4.2.2 TESTING This section is concerned with the tests that were carried out to verify and monitor the operation and performance conditions of the electric bicycle. the d. This involves the following tests as they relate to this system: Unit Testing Integration Testing System Testing 4. the speed and switch controller and the bicycle itself to ensure optimum operating conditions before the various components were mounted on it.c battery to ensure the required voltage output. step-down transformer rated 230/12 V. The micro-controller also acts as a switching.1.1 UNIT TESTING The electric bicycle composes of different units coupled together to make up the whole system.2. All outputs were tested with a multi-meter and oscilloscope 4. a capacitor and a voltage regulator output.1.2. All tests were carried out at the various outputs of these components to ensure the required wave form in cases of a. controlling device and was monitored to ensure it performed its switching. . a diode bridge.c and the expected voltage output as the case maybe.4. The different switching.9 LED indicator at OFF . Fig 4. control levels were indicated in this project using a blue-colored LED. 4. the battery and the varying the system speed using the speed controller.Fig 4. 4. This involved riding the bicycle electrically with the aid of the d.1. The integration tests in this project include the following: The test was about connecting the power supply unit to the battery.2 INTEGRATION TESTING Integration testing was carried out to evaluate the interaction between distinct and separate modules or stage of the project. tyres and brakes e.10 LED indicator at ON 4. This was necessary as the project involved integration of several components and binding them together to form a complete system.c motor.3 MECHANICAL BICYCLE TEST The bicycle itself was tested mechanically to ensure optimum operating conditions of the wheels.3 OVERVIEW OF TESTING INSTRUMENTS The implementation and testing phase required the use of several testing instruments and equipment such as .c before the various components were mounted on it. the battery connected to the microcontroller unit then to the motor The test was about the coupling of the motor to the rear wheel 4. This test involved the complete operation of the system based on the interaction between the several modules.3 SYSTEM TESTING System testing was done to test the complete bicycle.2.t.2.2. The successful interaction between these units ensured the successful implementation of the system all together. a. DIGITAL MULTIMETER: The digital multi-meter is used to measure resistance. frequency. 4.c voltage and current. OSCILLOSCOPE: The oscilloscope is a device that is used to generate the waveforms of corresponding component outputs.000 DC Motor 1 10. It was very critical in the process of implementing the design on the Vero-board for the measurement of parameters like voltage. continuity and in some cases frequency measurement.c or d.000 PIC18F1320 1 2.4 BILL OF QUANTITY COMPONENT UNIT UNIT PRICE (NGN) PRICE (NGN) Bicycle 1 15.000 12v dc battery 1 12. current and resistance values of components.c signals.000 12.000 2. The digital multi-meter was handy throughout the entire construction as its use couldn‟t be over emphasized.c and pulsating d. It was used to determine and confirm the pulse signals generated by the circuit for a.000 ULN2003 IC 1 150 150 Relay 2 250 500 Transformer 1 250 250 Switch/Control button 2 30 60 Resistor 4 10 70 Capacitor 1 40 40 Voltage Regulator 2 110 220 Vero board 2 50 100 Microcontroller .000 10.000 15. 000 2. .000 TOTAL 55.Power chain and Gear 1 2.000 Expenses Transportation 3.000 welding Miscellaneous 5. the implementation and testing phase were very successful and the design specifications were fully realized.000 Controller case 1 200 200 Mounting and 5.5 CONCLUSION In conclusion.590 4. 2 SUMMARY The present available technology has made it possible for the actualization and the full implementation of the project. This technology is pollution free and is capable of operating with a very low cost. 5. This section shall begin with a summary of the approach taken. the challenges faced and the recommendations for future direction of this project.CHAPTER FIVE CONCLUSION 5.4 CHALLENGES ENCOUNTERED . Simplicity of operation: the system operates a simple on/off switch mechanism and for speed control 1/2 depending on the speed required. 1 for a low speed and 2 for a higher Power transmission efficiency. The embedded devices were properly customized on an existing bicycle with the frame still intact.3 ACHIEVEMENTS The project has been able to realize the following accomplishments: The normal bicycle pedaling function is retained and fully functional. The system was developed to serve as assistance and not for full mobility. The PIC microcontroller technology was implemented as the control technology over the Pulse Width Modulation (PWM). 5. 5.1 MAJOR AIM The fundamental aim of this project is to incorporate an electromechanical system unto an existing bicycle frame to power the bicycle without damaging the structural balance and rotor abilities of the bicycle. for example. Compared with other conventional motors. 5. its advantages include the following (i) Energy efficiency: This is the biggest advantage of a hub wheel motor. Some of the observations include Incorporation of a hub wheel motor: The hub wheel motor is an electric motor that is incorporated onto the hub of a wheel and drives it directly. It was not an easy task in determining. Mechanical coupling of the bicycle needed a lot of manual labor and I only had a technician for assistance. Difficulty in balancing cost and functionality. battery output required as it required lots of analysis and calculations. the right motor. A conventional vehicle uses mechanical means to transmit power from a centrally mounted engine/motor to the wheels. budget available and delivery according to the initial specifications.5 KNOWLEDGE ACQUIRED I have gained adequate and valuable understanding on how to design and analyze electric circuits with a fundamental understanding of the various electronic components in an electric circuit. 5. I have been able to understand the fundamentals of a micro-controller and programming in C# I now have a sound understanding of project management as it entails time.6 RECOMMENDATIONS Even though the system seems to have achieved the basic requirements of an electric bicycle. The programming of the micro-controller operation in C# was quite challenging. . there is need for possible further research.The challenges encountered during the design and implementations of this project are as follows: Some of the electronic components got damaged during soldering. In terms of the dc motor controller system used which was a micro-controller. gear ratio. a system with a higher voltage would draw a lower current and hence reduce the head produced in the speed control circuit. An electric motor mounted directly inside a wheel without any mechanical transmission will avoid all such losses. it should be noted that the Electric Bicycle should not be relied on completely for transportation as it mainly only serves as an assistance to the pedaling system. the weight of the system is reduced because no structural and transmission parts are used. (ii) Reduced weight: due to the motor being mounted directly inside the wheel. Upgrading to a higher voltage system and retaining system weight: A 36-V or even 48-V system would be more stable and would be a lot better than the 12 V used as the current drawn by the motor will be low. Thus. The 12-V system has a low power and the current drawn was high. Higher current value creates more heat and a much bigger motor controller. loses occur due to heating from the friction and through the transmission system.7 CONCLUSION In conclusion. Solar cell battery charger: the application of a solar cell battery charger can make the electric bicycle more mobile than it currently is because it gives access to electricity for recharging anywhere there‟s sunlight. 5. .Hence. wikipedia. [9] Song Jie Hou. 2006 [2] B.org/wiki/PIC_microcontroller> [11] Braking [online] Available at: <en. Allison Kipple “The Design. [3] Ben Rogowitz and Dr. 2012.. Michio Sugawara.REFERENCES [1] B. and Akiya Kozawa “Charging and Discharging Method of Lead Acid Batteries Based on Internal Voltage Control” [10] PIC Microcontroller [online]: Available at <http://en. Hajimu Ikeda. Kumar and H. O. Shigeyuki Minami. Lecture Note Covenant University. Department of Electrical Engineering & Computer Science.org/wiki/Braking> . Center for Engineering Education and Practice. Ota.Eng. Northern Arizona University [4] Hope. University of Michigan-Dearborn [6] History of the Electric Bicycle [online] Available at: <http://elmo03057. O. Simulation. Sumit Mahindrakar and Prof. Covenant University.E “Programmable Logic Controller (PLC)”. May 24–28.L Theraja and A. and Construction of an Electric Bicycle”. unpublished B. 2012.” National Aerospace and Electronics Conf. 1993.hubpages.Eng Lecture Notes. Yoichiro Onishi. unpublished B. India.S “Electric Drives”.wikipedia. [5] Joe LaPointe and Gregory Huh “Electric Assisted Bicycle”. Ota.K Theraja “A textbook of electrical technology” S chand & company. Jayashree Deka “An Improved & Efficient Electric Bicycle system with the Power of Real-time Information” [8] James. Oman. vol.com/hub/The-History-ofthe-Electric-Bicycle> [7] Chetan Mahadik. College of Engineering and Computer Science. 1. “Power control for battery-electric bicycles. wikipedia.shtml> .[12] Electric Bicycle Laws [online] Available at: < en.org/wiki/Electric_bicycle_laws> [13] PIC18F1320 [online] Available at: < http://www.com/Microchip/PIC18F1320.futurlec. SPEED_2}. sbit MOTOR_SPEED_1_Direction at TRISB0_bit. sbit MOTOR_SPEED_2 at LATA3_bit. . enum STATE{OFF =0. sbit MOTOR_SPEED_2_Direction at TRISA3_bit. char machine_state = OFF.APPENDIX A SOURCE CODE CODE FOR SWITCHING ON/OFF AND CONTROLLING MOTOR SPEED sbit LED1 at LATB5_bit. sbit LED1_Direction at TRISB5_bit. sbit MOTOR_SPEED_1 at LATB0_bit. char i. SPEED_1. char blink_counter = 0. switch(machine_state){ case OFF: MOTOR_SPEED_1 = 0. TMR0H = 0x3C. LED1 = 0. MOTOR_SPEED_2 = 0. break. TMR0L = 0xB0. case SPEED_1: .void Interrupt(){ if (TMR0IF_bit){ TMR0IF_bit = 0. blink_counter++. MOTOR_SPEED_2 = 0. case SPEED_2: if(blink_counter>=1){ MOTOR_SPEED_1 = 0. MOTOR_SPEED_1 = 1. } . blink_counter =0. MOTOR_SPEED_2 = 1. blink_counter =0. } break.if(blink_counter>6){ LED1 = ~LED1. LED1 = ~LED1. default: machine_state = OFF.break. } } } void InitTimer0(){ . TMR0H = 0x3C. .//OUTput direction MOTOR_SPEED_1_Direction = 0. MOTOR_SPEED_2_Direction = 0. MOTOR_SPEED_2 = 0. GIE_bit = 1.T0CON = 0x82. LED1 = 0. MOTOR_SPEED_1 = 0. TMR0L = 0xB0. TMR0IE_bit = 1. } void main(){ LED1_Direction = 0. while(1){ if (Button(&PORTB.// configure button pin as input ADCON1 = 0x70.// port b is all digital InitTimer0(). IRCF2_bit = 1. 4. IRCF1_bit = 1. Delay_ms(500).IRCF0_bit = 1. } . 20. TRISB4_bit = 1. 0)){ // check button STATE machine_state++. } } .
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