Claims:1. A solar powered electric tricycle for physically challenged persons comprises a tricycle, solar panel, charge controller, battery, motor, microcontroller, liquid crystal display, ultrasonic sensor and a power controller.

2. The tricycle as claimed in claim 1, wherein said charge controller is an essential part of nearly all power systems that charge batteries, whether the power source are solar panels, wind, hydro, fuel, or the utility grid; wherein Its purpose is to keep your deep cycle batteries properly fed and safe for the long term.

3. The tricycle as claimed in claim 1, wherein Charge controllers block reverse current and prevent battery overcharge; and Some controllers also prevent battery over discharge, protect from electrical overload, and/or display battery status.

4. The tricycle as claimed in claim 1, wherein a solar charging system is incomplete without charge controller; and said charge controller limits the rate at which electric current is added to or drawn from electric batteries.

5. The tricycle as claimed in claim 1, wherein charge controller prevents overcharging and may protect against overvoltage, which may reduce battery performance or lifespan. It may also prevent complete draining ("deep discharging") of a battery, or perform controlled discharges, depending on the battery technology, to protect battery life.

6. The tricycle as claimed in claim 1, wherein The charge controller is designed using the MOSFET (Metal Oxide Semiconductor Field Effect Transistor); which is a unipolar transistor and used as an electronic switch and to amplify electronic signals.

7. The tricycle as claimed in claim 1, wherein a motor controller is the actual device that energizes and de-energizes the circuit of the motor so that it can start and stop; and wherein said Motor controller includes some or all of the following motor control functions: starting, stopping, over-current protection, overload protection, reversing, speed changing, jogging, plugging, sequence control, and pilot light indication.

8. The tricycle as claimed in claim 1, wherein ultrasonic sensors measure distance by using ultrasonic waves.; and the sensor head emits an ultrasonic wave and receives the wave reflected from the target. Ultrasonic Sensors measure the distance to the target by measuring the time between the emission and reception.

9. The tricycle as claimed in claim 1, wherein all conductors under North-pole carry currents in one direction while all the conductors under South-pole carry currents in the opposite direction.

10. The tricycle as claimed in claim 1, wherein when the conductor moves from one side of a brush to the other, the current in that conductor is reversed.; at the same time, it comes under the influence of the next pole which is of opposite polarity.
, Description:Title of the Invention
SOLAR POWERED ELECTRIC TRICYCLE FOR PHYSICALLY CHALLENGED PERSONS
Field of the Invention
This invention relates to solar powered electric tricycle for physically challenged persons. More particularly relates to solar powered tricycle is to bring increased mobility to disabled persons by providing the solar powered tricycle at lower cost comparatively with the existing tricycle.
Background of the Invention
Electric vehicle uses 100% electric power by using an electric motor instead of an internal combustion engine to provide motive force.
Solar-powered vehicles (SPVs) use photovoltaic (PV) cells to convert sunlight into electricity. The electricity goes either directly to an electric motor for powering the vehicle or to a special storage battery to store the available energy. PV cells produce electricity only when the sun is shining. Without sunlight, the solar powered tricycle depends on electricity stored in its batteries. Since 1970s, inventors, government and industry have helped to develop solar-powered cars, boats, bicycles and even airplanes.
There are several types of tricycle that can be chosen such as paddle tricycle, motorized tricycle and electric tricycle. But there is some weakness about this type of tricycle. To overcome this weakness, we have developed a project.
In olden days, pedal tricycle needs lots of human energy to pedal the tricycle. The users will surely become tired after using this tricycle. At present, the tricycle uses fuel, which is costly and not eco-friendly.
It has been observed that physically challenged people are basically using some assistive devices like crutches, artificial legs, etc., With the help of which they are travelling from one place to another by a manual movement or by petroleum vehicles which causes physical weakness and environmental pollution.
For the welfare of surroundings and physically challenged people, we have designed a solar powered electric tricycle which is charged with the help of solar energy and stored in a battery. For the benefit of users, the amount of charge which is available in the battery is displayed to the users.
Prior Arts :
1) DANIEL DOURTE, DAVID SANDBERG, TOLU OGUNDIPE, presented a paper on "ELECTRIC TRICYCLE: A. APPROPRIATE MOBILITY":
The aim of this project is to add an electric power train and control system to the current hand-powered tricycle to provide tricycle users with improved levels of mobility. The design objectives required a simple and affordable design for the power train and controls, a design that needed to be reliable, sustainable, and functional. The design of the Electric Tricycle is adaptable to the current hand-powered tricycles with little modification. The design consists of an electric motor, a drive system, motor and steering controls, and a power supply.
2) M. REDDI SANKAR, T. PUSHPAVENI, V. BHANU PRAKASH REDDY, presented a paper on "DESIGN AND B. DEVELOPMENT OF SOLAR ASSISTED BICYCLE":
The solar assisted bicycle developed is driven by DC motor fitted in front or rear axle housing & operated by solar energy. The solar panels mounted on the carriage will charge the battery & which in turn drive the hub motor. When the bicycle is idle, the solar panel will charge the battery. This arrangement will replace the petrol engine, the gear box & the fuel tank in case of a two-wheeler or a chain sprocket, chain & gear shifting arrangement of a conventional bicycle being used by most common man. As a part of dissertation work, the solar assisted bicycle is fitted with a dc hub motor on front axle of a bicycle with power rating of 250W and with a travelling speed of around 25-30 kmph. It is provided with a pair of lead acid batteries of 35 Ah each, a photovoltaic solar panel with capacity of 20 watt, a voltage regulator of 24v 10 Amp, accelerator and motor controller of 24v 25Amp. There is also a provision for charging of the battery with 220-240V, AC wall outlet supply, in case of poor solar supply due to cloudy weather.
3) N. SASIKUMAR, DR.P. JAYASUBRAMANIAM, presented a paper on "SOLAR ENERGY SYSTEM IN INDIA":

Conventional energy sources like coal, oil, natural gas, etc., are limited in quantity, and if these continue to be depleted at the present rate, these will be exhausted in the coming decades. Energy demand is resulting in the creation of fossil fuel-based power plants leading to substantial greenhouse gas emissions having an adverse impact on global warming and climate change Solar energy offers a clean, climate-friendly, abundant and inexhaustible energy resource to mankind. The costs of solar energy have been falling rapidly and are entering new areas of competitiveness. Solar Thermal Electricity (STE) and Solar Photo Voltaic Electricity (SPV) are becoming competitive against conventional electricity generation in tropical countries Solar photovoltaic (SPV) cells convert solar radiation (sunlight) into electricity. A solar cell is a semiconducting device made of Silicon materials, which, when exposed to sunlight, generates electricity. Solar cells are connected in series and parallel combinations to form modules that provide the required power.
4) ABDULKADIR BABA HASSAN, presented a paper on "DESIGN AND FABRICATION OF A MOTORIZED D. PROTOTYPE TRICYCLE FOR THE DISABLE PERSONS":
This project design is embodied on a motorized tricycle for disabled Persons. The tricycle was specifically designed to suit wheelchair occupants of healthy Upper torso with pelvic to foot restraint. It is also designed to suit a commonly available Wheel chair. The level of relationship between the disabled people in the society has highly being jeopardized; therefore, this project was designed to correct the difficulties in mobility of the wheelchair users. The main aim of the project design is to ease mobility for the physically challenged and provide adequate comfort they desire. Existing tricycles for the disables require the disabled person to dismount from the wheelchair onto the tricycle. The motorized tricycle in this project is designed to overcome this problem by allowing the disabled person to wheel up or down his wheelchair onto or down the tricycle. This is achieved using a specially designed platform that allows the wheel chair to be wheeled up or down. The prototype of this tricycle has been fabricated.
5) T1LAKISWARAN A/L SAMURGAM, Presented a paper on “DEVELOPMENT OF BATTERY POWERED TRICYCLE”:
The main purpose of this project is to develop a battery powered electric motor tricycle which can be used as a simple transportation and for economy reasons, to develop a battery powered electric motor tricycle which can be used as a simple transportation and for economy reasons. A motorized tricycle is a three wheeled bicycle with an attached motor used to assist with pedaling. Generally considered as a vehicle, tricycles are usually powered by electric motors or small internal combustion engines and have function as electric bicycles. Some can be propelled by the motor alone if the rider chooses not to pedal; while in others the motor will only run if the rider pedals. Electric bicycles are generally powered by rechargeable batteries.
6) YOGESH SUNIL WAMBORIKAR, ABHAY SINHA, Presented a paper on "SOLAR POWERED VEHICLE":
The renewable energy is vital for today's world as in near future the nonrenewable sources that we are using are going to get exhausted. The solar vehicle is a step in saving these nonrenewable sources of energy. The basic principle of solar car is to use energy that is stored in a battery during and after charging it from a solar panel. The charged batteries are used to drive the motor which serves here as an engine and moves the vehicle in reverse or forward direction. The electrical tapping rheostat is provided to control the motor speed. This avoids excess flow of current when the vehicle is supposed to be stopped suddenly as it is in normal cars with regards to fuel. This idea, in future, may help protect our fuels from getting extinguished.
7) ARUN MANOHAR GURRAM, P.S.V. RAMANA RAO, RAGHUVEER DONTIKURTI, presented a paper on "SOLAR G. POWERED WHEEL CHAIR: MOBILITY FOR PHYSICALLY CHALLENGED":
Personal mobility means freedom for the physically challenged. One of the best inventions in the medical field that helped both the elderly and the handicapped is the mobility vehicle. The fact that they are no longer depending on someone else to perform daily duties is a big step forward. On the journey to mobility and freedom, motorized scooters and wheelchairs are the tools to finish that journey. With scooters and wheelchairs, there is a small inconvenience to mobility independence. The addition of some devices enables persons with physical disabilities a comfortable travel beyond their own homes. The present work involves in design and fabrication of solar powered wheel chair. A motorized wheelchair, power chair, electric wheelchair or electric-powered wheelchair (EPW) is propelled by means of an electric motor rather than manual power.
8) SHUH JING YING, STEPHEN SUNDARRAO, presented a paper on "POWER ASSIST HAND TRICYCLE WITH H. BATTERY FOR DISABLED PERSONS":
A hand tricycle is originally designed to be used by a disabled person with lower extremity weakness but with power in his or her hands and arms. This tricycle is modified by the addition of an electric motor and battery to help power the vehicle. The functions of the original design are not altered. The battery, motor, speed reducer and clutch are properly arranged. An additional sprocket is attached to the drive wheel. The motor controller can adjust the speed in five different settings and the tricycle can be driven forward or backward. They salvaged a lightweight tricycle weighing about thirty pounds from a storage area. It was not in working condition. The wheels are arranged with one fixed direction drive wheel in front and two pivoting wheels for steering in the rear. Two handles beside the seat are used for hand control of the steering. A large sprocket 25.4 cm in diameter located in front of the driver relates to two crank handles for the driver's hands to power the vehicle.
9) CHETAN MAHADIK, SUMIT MAHINDRAKAR, PROF. JAYASHREE DEKA, presented a paper on "AN IMPROVED I.& EFFICIENT ELECTRIC BICYCLE SYSTEM WITH THE POWER OF REAL-TIME INFORMATION SHARING":
This paper presents the development of an associate degree "Electric Bicycle System? with an innovative approach. The aim of this paper is to show that the normal bi- cycle can be upgraded to electric one by some means– that including the development of a regenerative braking system and innovative BLDC motor control. The main components of the electric bicycle are brushless DC motor, motor controller, photo-voltaic, dry cell battery and solar panel. Also throttle and extra features such as horn, speedometer, and LED signal etc. The power source for this system is given by dry cell battery. The output of dry cell battery is 48V. There are multiple forms of charging source is used such as AC voltage through an outlet, solar energy and mechanical pedal charging system. The source of battery charging is photovoltaic solar panel and it is light weight. The solar panel output is 12V and 20 watts. Also, they use mechanical pedal charging system, so dynamo is use for this charging system.
10) QINGFENG SU, GENFA ZHANG, JIANMING LAI, SHIJUN FENG, AND WEIMIN SHI, presented a paper on, J."GREEN SOLAR ELECTRIC VEHICLE CHANGING THE FUTURE LIFESTYLE OF HUMAN":
Electric vehicle with more advantages of no noise, no pollution, saving energy and reduce carbon dioxide emissions is to power-driven vehicle with a motor drive wheels moving. Solar electric vehicle can make to reduce our greenhouse gas emissions and other pollution. All advantages of solar electric vehicle make research and application of solar electric vehicle as a “hot spot” of automotive industry and the trend of future cars. Solar electric vehicle is made of PV panels, battery, electric motor, vehicle controller and vehicle body. Solar electric vehicle drives using dual mode of PV and battery hybrid. It can be achieved PV-driven and battery-driven independently. In good sunny conditions, the full charge endurance of solar electric vehicle can be increased about 35% substantially compared with no PV panels. Solar electric vehicle can achieve low-carbon, energy saving, environmental protection and true zero-emissions for the future of human life.
Summary of the Invention
A three-wheeled wheelchair was built in 1665 by a paraplegic German man, Stephan Farffler, who wanted to maintain his mobility. Since he was a watchmaker, he was able to create a vehicle that was powered by hand cranks.
In 1789, two French inventors developed a three-wheeled vehicle, powered by pedals. They called it the tricycle. In 1818, British inventor Denis Johnson patented his approach to designing tricycles. In 1876, James Starley developed the Coventry Lever Tricycle, which used two small wheels on the right side and a large drive wheel on the left side and the power was supplied by hand levers.

In 1877, Starley developed a new vehicle called as the Coventry Rotary, which was one of the first rotary chain drive tricycles. Starley’s inventions started a tricycling craze in Britain by 1879. There were twenty types of tricycles and multi-wheel cycles produced in Coventry, England. By 1884, there were over 120 different models produced by 20 manufacturers. The first front steering tricycle was manufactured in 1881 by “The Leicester Safety Tricycle Company in England, which was brought to the market in 1882 costing £18. They also developed a folding tricycle at the same time.
Uganda was one of the first places in Africa to design and build a wheelchair that was suitable for the rough roads and infrastructure found throughout the continent. Doctor Ronald Lawrie (R.L.) Huckstep introduced a locally designed wheelchair to Uganda in 1967 (Mukisa, 2008). Huckstep designed the first wheelchair for the majority world at the Mulago Orthopaedic Workshop in Kampala, Uganda (Mukisa, 2008). The Huckstep wheelchair also called the Kampala wheelchair, produced using bicycle parts and simple fabrication techniques. It was designed and built to be affordable, durable, and very serviceable in exchange for a bulky and rigid frame. Therefore, the Huckstep wheelchair is not easily used for public transit, small pathways, or indoors (Mukisa, 2008).
A decade after the Huckstep wheelchair was developed, a single-sided bicycle hub became available throughout Uganda (Mukisa, 2008). It was cored and filled with a solid steel axle, which eliminated the need for the exterior frame that usually supports a standard dual-sided bicycle hub. The single-sided bicycle hub has made wheelchairs more mobile and better suited to indoor use.
Hand-operated tricycles were documented shortly after the Huckstep wheelchair was developed. The tricycle is one of the most successful wheelchair designs produced throughout Africa and Asia for many reasons. Tricycles are larger than wheelchairs, because they require lower tolerances and also tricycles have gears that make it faster for PWDs to travel long distances.
The tricycle design has been widely adapted by local producers throughout Africa and Asia. This has led to certain variants of the tricycle that suffer from several mechanical issues including inefficient gearing and major stress and failure points within the frame. The School of Industrial Design at Carleton University has been involved in the betterment of the design of tricycles in collaboration with CanUgan. This included a structural evaluation and improved manufacturing approach in 2013 and the identification of using the wheelchair for income generation (Cox, 2014). In addition, the opportunity for a wheelchair and tricycle combination has been explored at the department
DISADVANTAGES
? The manual wheelchair might not be suitable for you if you don't have required strength to move it or someone always there for you to move your chair as per your requirements.
? High level of strength requires
? You need to rely on someone to push the chair
? Can't use it for longer distance movement
? Can't control it properly
? Use of conventional energy source
? Causes environmental pollution
Detailed Description of the Invention
The solar powered tricycle for physically challenged persons is a tricycle in which the human energy or conventional fuel is used to run the tricycle. Solar energy is used to charge the battery. Two or more photovoltaic cells may be used to harness solar energy. In this proposed project, Lead acid batteries are used. Battery gives the required voltage to the dc motor to run the tricycle. The controllers are used to provide enough voltage to charge the battery that it limits and boosts the voltage for the high performance and high life span of the battery. The voltage produced by the solar panel and the drain voltage of the battery is measured and sent as the analog input to the microcontroller. The remaining voltage and the empty time of the battery is calculated. The microcontroller is interfaced with the LCD to display the calculated values. Ultrasonic sensor is used to prevent the physically challenged person from accidents.
ADVANTAGES:
1. Solar energy creates no pollution. This energy is more practical than burning of oil. Because it releases harmful greenhouses gases, carcinogens and carbon dioxide into our precious air.
2. Solar energy is a completely renewable resource. This means that even when we cannot make use of the sun's power because of nighttime or cloudy and stormy days, we can always rely on the sun showing up the very next day as a constant and consistent power source.
3. Solar panels and solar lighting may seem quite expensive when you first purchase it, but in the long run you will find yourself saving quite a great deal of money. It does not cost anything to harness the power of the sun. Paying for oil is an expensive prospect and the cost is still rising consistently.
4. Solar powered panels and products are easy to install. Wires, cords and power sources are not needed at all, making this an easy prospect to employ.
5. Solar power technology is improving consistently over time, as people begin to understand all the benefits offered by this incredible technology. As our oil reserves decline, it is important for us to turn to alternative sources for energy.
6. Oil, which is currently used to power the homes, is not a renewable resource. This means that as soon as the oil is gone, it is gone forever, and we will no longer have power or energy. Very little maintenance is required to keep solar cells running. There are no moving parts in a solar cell tend to last a good long time with only an annual cleaning to worry about.
7. Solar cells make absolutely no noise at all. They do not make a single peep while extracting useful energy from the sun. On the other hand, the giant machines utilized for pumping oil are extremely noisy and therefore very impractical.
8. Because an SPV has few moving parts, service requirements are less than for conventional cars.
9. Since there is no internal combustion engine and no combustion takes place, there are no emissions.
10. Electric vehicles are very quiet. Noise comes only from the electric motors.
11. SPV's rely on solar power, and the only requirement is that they must be operated in sunshine.
12. Added emissions are not produced by power plants, since SPV's do not rely on utility-generated electricity.
13. Efficient vehicles have traveled a mile on less energy than a 100-watt light bulb consumes in one hour. (For a gasoline-powered car to achieve comparable efficiency, it would need to get 500 miles per gallon).
BLOCK DIAGRAM:
The various components present in the proposed system are shown in the figure
3.1. The system consists of four main components, solar panel, controller, battery and dc motor. The solar panel converts the solar energy to electricity. The controller provides enough voltage to the battery. The battery stores the energy and it is utilized by the motor which in turn drives the bicycle. The state of the charge in the battery is measured and the information is given to the user as drain voltage and empty time.
HARDWARE DESCRIPTION
OVERVIEW:
The proposed system consists of four main blocks: the solar panel which acts as a source, the battery which acts as a storage unit, the DC motor and the ultrasonic sensor. The solar panel is connected to the charge controller. The power controller is connected in between the battery and the dc motor. The ultrasonic sensor placed on back side of the tricycle.
SOLAR PANEL:
The solar bicycle is operated by solar energy. The lead acid battery is charged with voltage generated due to solar energy with the help of a photovoltaic cell. Solar cells convert the solar energy directly into electricity using photovoltaic effect. The photovoltaic effect involves conversion of electromagnetic radiation into electrical energy. The photoelectric and photovoltaic effects are related to sunlight, but are different in that electrons are ejected from a material’s surface upon exposure to electromagnetic radiation of sufficient energy in photoelectric, and thus the electrons that are generated are transferred to different bands of valence to conduction within the material. Thus, this results into buildup of voltage between two electrodes in photovoltaic. Solar cells are connected electrically and manufactured as a module with a sheet of glass on top to allow light to pass and protect the semiconductor from the weather.
Number of solar cells are electrically connected to each other and mounted in a single support structure or frame is called a photovoltaic module. Modules are designed to supply electricity at a certain voltage, such as a common 12-volt system. The current produced is directly dependent on the intensity of light reaching the module. Several modules can be wired together to form an array. Photovoltaic modules and arrays produce direct current electricity. They can be connected in both series and parallel electrical arrangements to produce any required voltage and current combination.
The solar panel of about 75W is used to charge the lead acid battery. The panel is placed on the roof of the tricycle. It is connected to the battery via charge controller. It supplies sufficient voltage to store in the two 12v battery.
CHARGE CONTROLLER:
A charge controller is an essential part of nearly all power systems that charge batteries, whether the power source are solar panels, wind, hydro, fuel, or the utility grid. Its purpose is to keep your deep cycle batteries properly fed and safe for the long term.
The basic functions of a controller are quite simple. Charge controllers block reverse current and prevent battery overcharge. Some controllers also prevent battery over discharge, protect from electrical overload, and/or display battery status.
A solar charging system is incomplete without charge controller. A charge controller limits the rate at which electric current is added to or drawn from electric batteries. It prevents overcharging and may protect against overvoltage, which may reduce battery performance or lifespan. It may also prevent complete draining ("deep discharging") of a battery, or perform controlled discharges, depending on the battery technology, to protect battery life. The terms "charge controller" or "charge regulator" may refer to either a standalone device, or to control circuitry integrated within a battery pack, battery powered device, or battery charger.
The charge controller is designed using the MOSFET (Metal Oxide Semiconductor Field Effect Transistor). It is the most widely used types of insulated gate FETs (Field Effect Transistor). They are used in various applications due to its simple working phenomena and advantages over other FETs. It is a unipolar transistor and used as an electronic switch and to amplify electronic signals. The device has three terminals consisting of a source, gate and drain. In recent years, its discovery has led to the dominant usage of these devices in digital integrated circuits due to its structure. MOSFETs provide greater efficiency while operating at lower voltages. Absence of gate current results in high input impedance producing high switching speed. They operate at lower power and draws no current.
Blocking reverse current:
Solar panels work by pumping current through the battery in one direction. At night, the panels may pass a bit of current in the reverse direction, causing a slight discharge from the battery. The potential loss is minor, but it is easy to prevent. Some types of wind and hydro generators also draw reverse current when they stop.
In most controllers, charge current passes through a semiconductor (a transistor) which acts like a valve to control the current. It is called a "semiconductor" because it passes current only in one direction. It prevents reverse current without any extra effort or cost.
In some older controllers, an electromagnetic coil opens and closes a mechanical switch. The relay switches off at night, to block reverse current. These controllers are sometimes referred to as shunt controllers.
If the solar panel array is used only to trickle-charge a battery, the charge controller is not needed. This is a rare application. A diode used for blocking the reverse current is called a "blocking diode".
Preventing overcharge:
When a battery reaches full charge, it can no longer store incoming energy. If energy continues to be applied at the full rate, the battery voltage gets too high. Water separates into hydrogen and oxygen and bubbles out rapidly. (It looks like it's boiling so we sometimes call it that, although it's not actually hot.) There is excessive loss of water, and a chance that the gasses can ignite and cause a small explosion. The battery will also degrade rapidly and may possibly overheat. Excessive voltage can also stress your loads (lights, appliances, etc.) or cause your inverter to shut off.
Preventing overcharge is reducing the flow of energy to the battery, when it reaches a specific voltage. When the voltage drops due to lower sun intensity or an increase in electrical usage, the controller again allows the maximum possible charge. This is called "voltage regulating". It is the most essential function of all charge controllers. The controller looks at the voltage and regulates the battery charging in response.
Some controllers regulate the flow of energy to the battery by switching the current fully on or fully off. This is called "on/off control." Others reduce the current gradually. This is called "pulse width modulation" (PWM). Both methods work well when set properly for your type of battery.
A PWM Solar Charge Controllers holds the voltage more constant. If it has two- stage regulation, it will first hold the voltage to a safe maximum for the battery to reach full charge. Then, it will drop the voltage lower, to sustain a "finish" or "trickle" charge. Two-stage regulating is important for a system that may experience many days or weeks of excess energy (or little use of energy). It maintains a full charge but minimizes water loss and stress.
The voltages at which the controller changes the charge rate are called set points. When determining the ideal set points, there is some compromise between charging quickly before the sun goes down, and mildly overcharging the battery. The determination of set points depends on the anticipated patterns of usage, the type of battery, and to some extent, the experience and philosophy of the system designer or operator. Some controllers have adjustable set points, while others do not.
BATTERY:
The batteries remain as the technology of choice for automotive SLI (Starting, Lighting and Ignition) applications because, they are robust and tolerant to abuse. Due to their low cost used for higher power applications with intermittent loads.
Despite some of the shortcomings lead acid batteries are still being specified for power net applications (36 Volts 2 kWh capacity) because of the cost, but this is probably the limit of their applicability and NiMH and Li-Ion batteries are making inroads into this market. For higher voltages and cyclic loads other technologies are being explored.
Lead acid batteries are composed of a Lead dioxide cathode, a sponge metallic Lead anode and a sulphuric acid solution electrolyte. This heavy metal element makes them toxic and improper disposal can be hazardous to the environment. The cell voltage is 2 Volts.
The two 12v and 7.2Ah batteries are connected in series. So that 24v is supplied to the dc motor to drive the bicycle. The battery stores the energy from the 75w solar panel. The solar panel relates to the battery via power controller.
Overall reaction:
Pb(s) + PbO2(s) + 2H2SO4(aq) ? 2PbSO4(s) + 2H2O (4.1)

The dead battery is charged effectively by the solar energy from the solar panel.
After charging completely, the stored energy in the battery is used to drive the dc motor.
DC MOTOR:
A DC motor is an electrical machine which converts electrical energy into mechanical energy. The working of DC motor is based on the principle that when a current carrying conductor is placed in a magnetic field, it experiences a mechanical force. The 250w and 24v gear motor is driven by supplying 24v from the battery. Thus, it drives the electric tricycle efficiently. The tricycle can run at the maximum speed of about 35-40 kmph.
Working:
When the terminals of the motor are connected to an external source of DC supply, the field magnets are excited developing alternate north and south poles and the armature conductors carry currents.
All conductors under North-pole carry currents in one direction while all the conductors under South-pole carry currents in the opposite direction. Since, each armature conductor is carrying current and is placed in the magnetic field, a mechanical force act on it. On applying Fleming’s left-hand rule, it is clear that force on each conductor is tending to rotate the armature in the anticlockwise direction. All these forces add together to produce a driving torque which sets the armature rotates. When the conductor moves from one side of a brush to the other, the current in that conductor is reversed. At the same time, it comes under the influence of the next pole which is of opposite polarity. Consequently, the direction of the force on the conductor remains the same. It should be noted that the function of a commutator in the motor is the same as in a generator. By reversing current in each conductor as it passes from one pole to another, it helps to develop a continuous and unidirectional torque.
This dc motor is driven with the help of the battery. That is 250w and 24v gear motor is driven by supplying 24v from the battery. The motor runs according to the above explained principle. Thus, it drives the electric tricycle efficiently. The motor drives effectively until the charge in the battery gets emptied. Even though the battery gets discharged completely, the tricycle can be driven by pedaling.
MOTOR SPECIFICATIONS:
S.NO Specification Ratings
1. Torque Stall 40 Nm (400 kg-cm)
2. Torque Constant 8 Nm (80 kg-cm)
3. No load speed 400rpm / 30Kmph
4. Maximum load 150kg
5. Horsepower 0.33

Table 4.1: Specification of DC gear motor
BATTERY STATE MEASUREMENT:
To measure the state of charge of the batteries in real time we have designed the battery state sensor. The main components used are
1. Voltage measurement
2. Microcontroller (PIC16F877A)
3. LCD display
Voltage measurement:
The voltage sensor represents an ideal voltage sensor, that is, a device that converts voltage measured between two points of an electrical circuit into a physical signal proportional to the voltage. In voltage sensors, the measurement is based on the voltage divider rule.
Mainly two types of voltage sensors are available. They are
I. Capacitive type voltage sensor and
II. Resistive type voltage sensor.
We are using Resistive type voltage sensor to measure the state of the battery. There are two ways in converting the resistance of the sensing element to the voltage. First one is the simplest method that is to provide a voltage to the resistor divider circuit comprises of a sensor and a reference resistor which is represented below.
The voltage that is developed across the reference resistor or sensor is buffered and then given to the ADC. The output voltage of the sensor can be expressed as
A high resistive resistor is used to measure the drain voltage of the battery. The two 12v batteries are connected to it. By potential divider rule, the drain voltage of the battery is measured. The analog value of the voltage is sent as the input to the microcontroller.
Advantages of sensors over conventional measuring techniques:
1. Small in weight and size.
2. Personnel safety is high.
3. Degree of accuracy is very high.
4. It is non- saturable.
5. Wide dynamic range.
6. Eco-friendly.
7. It is possible to combine both the voltage and current measurement into a single physical device with small and compact dimensions.
MICROCONTROLLER:
The PIC microcontroller PIC16F877a is one of the most renowned microcontrollers in the industry. This microcontroller is very convenient to use. The coding or programming of this controller is also easier. One of the main advantages is that we can write or erase as many times as possible because it uses FLASH memory technology. It has a total number of 40 pins and there are 33 pins for input and output. PIC16F877A is used in many pic microcontroller projects. PIC16F877A also have many applications in digital electronics circuits.
PIC16f877a finds its applications in a huge number of devices. It is used in remote sensors, security and safety devices, home automation and in many industrial instruments. An EEPROM is also featured in it which makes it possible to store some of the information permanently like transmitter codes and receiver frequencies and some other related data. The cost of this controller is low and its handling is also easy. It is flexible and can be used in areas where microcontrollers have never been used before as in microprocessor applications and timer functions etc.
Features:
1. It has smaller 35 instructions set.
2. It can operate up to 20MHz frequency.
3. The operating voltage is between 4.2 volts to 5.5 volts. If you provide it voltage more than 5.5 volts, it may get damaged permanently.
4. It does not have internal oscillator like other PIC18F46K22, PIC18F4550.
5. The microcontroller operates with 5v of power supply. The voltage regulator is used to convert the 24 volts from the battery to 5 volts. The analog value of the drain voltage of battery is sent to the microcontroller. It is given as the input to the microcontroller. The remaining charge in the battery is calculated. Thus, the user is displayed with the information of remaining charge in the battery and the voltage producing by the solar panel.
LIQUID CRYSTAL DISPLAY:
A liquid-crystal display (LCD) is a flat-panel display or electronically modulated optical device that uses the light modulating properties of liquid crystals. LCDs are available to display arbitrary images (as in a general-purpose computer display) or fixed images with low information content, which can be displayed or hidden, such as preset words, digits, and seven-segment displays, as in a digital clock. LCDs can either be normally ON (positive) or OFF (negative), depending on the polarizer arrangement.
The data register stores the data to be displayed on the LCD. The data is the ASCII value of the character to be displayed on the LCD.
The command register stores the command instructions given to the LCD. A command is an instruction given to LCD to do a predefined task like
i. Initializing it
ii. Clearing its screen,
iii. Setting the cursor position,
iv. Controlling display & etc.
The port B of the microcontroller is interfaced with the LCD. The microcontroller calculates the remaining charge in the battery and the empty time of the battery. The four- digit, digital values of those calculated values are displayed to the user using the LCD display.
The distance between the tricycle and the nearby object is measured using the sensor and it is also displayed to the users.
POWER CONTROLLER:
A motor controller or power controller is a device or group of devices that serves to govern the performance of an electric motor in a predetermined manner. A motor controller might include a manual or automatic means for starting and stopping the motor, selecting forward or reverse rotation, selecting and regulating the speed, regulating or limiting the torque and protecting against overloads and faults.
A motor controller is the actual device that energizes and de-energizes the circuit of the motor so that it can start and stop. Motor controller may include some or all of the following motor control functions: starting, stopping, over-current protection, overload protection, reversing, speed changing, jogging, plugging, sequence control, and pilot light indication. The starting mechanism that energizes the circuit to an induction motor is called the “starter” and must supply the motor with sufficient current to provide adequate starting torque under worst case line voltage and load conditions when the motor is energized.
Over current protection interrupts the electrical circuit to the motor upon excessive current demand on the supply system from either short circuits or ground faults. Over current protection is required to protect personnel, the motor branch circuit conductors, control equipment and motor from the high currents.
ULTRASONIC SENSOR:
As the name indicates, ultrasonic sensors measure distance by using ultrasonic waves. The sensor head emits an ultrasonic wave and receives the wave reflected from the target. Ultrasonic Sensors measure the distance to the target by measuring the time between the emission and reception.
An optical sensor has a transmitter and receiver, whereas an ultrasonic sensor uses a single ultrasonic element for both emission and reception. In a reflective model ultrasonic sensor, a single oscillator emits and receives ultrasonic waves alternately. This enables miniaturization of the sensor head.
The distance can be calculated with the following formula:
where L is the distance, T is the time between the emission and reception, and C is the sonic speed. (The value is multiplied by 1/2 because T is the time for go-and-return distance.)

HARDWARE IMPLEMENTATION
CHARGE CONTROLLER:
Mosfet is used as Dc to DC convertor. MOSFETs have fast turn-off characteristic when compared with the characteristic of BJTs or IGBTs. The charge controller provides the protection for overvoltage and undervoltage generated by the solar panel. For these over voltages and under voltage protection Zener diode of 22Vand 11V are used respectively. If solar voltage exceeds 22V or reduced below 11V, Zener diodes will cut off the supply. So, the reversal of voltage from the battery to solar panel can be prevented.
BATTERY STATE AND SOLAR CHARGE MEASUREMENT:
By using the voltage divider rule, not only the voltage remaining in the battery but also the voltage producing by the solar panel could be measured. Resistive type voltage sensor is used here. Analog input from the sensor is given to the microcontroller which converts the analog input into the digital output. The output is displayed in the LCD. Here the resistances used for the measurement are two 100k ohm resistance and one 470k ohm resistance which are connected in series.
MOTOR SETUP:
A 24V,250W DC-gear motor is used here. To obtain high torque, gear motor is used. This motor is driven by supplying 24V from the battery. Thus, it drives the electric tricycle efficiently. The bicycle can run at the maximum speed of about 20-35 kmph.
MOTOR TRANSMISSION:
A chain and sprocket drive is a type of power transmission used in this tricycle. It consists of a roller chain engaged with two or more toothed wheels or sprockets, which is also used in engines as a drive from crankshaft to camshaft.
A chain can last anywhere from 500miles to 5000 miles, depending on the quality of the chain, the sprockets, how the bike is ridden, and the maintenance. For this purpose, the chain sprocket is used in the tricycle.
MANUAL TRANSMISSION:
If the motor transmission system gets failed, the transmission can be provided manually. The battery source may get failed, when there is no supply of solar energy. So, during these emergency situations, the manual transmission is utilized.
POWER CONTROLLER:
A 24V, 250W power controller is used. By this acceleration and braking of the motor can be controlled. The speed of the DC motor is controlled by using PWM.
Pulse Width Modulation, or PWM, is a technique for getting analog results with digital means. Digital control is used to create a square wave, (i.e.) the signal switched between on and off.
Pulse Width Modulation provides accuracy and quick response time. It provides high input Power Factor. Initial cost is low. PWM technique helps the motors to generate maximum torque even when they are running at lower speeds.
ULTRASONIC SENSOR:
Ultrasonic sensor is placed at the back side of the tricycle. It continuously measures the distance between the tricycle and the object behind the tricycle and update the distance in the LCD frequently. If any object gets closer less than 50cm with tricycle, then the buzzer turns on until the object clears the way or the tricycle moved away.
SOLAR PANEL SETUP:
Solar panel of about 75W is used to charge the lead acid battery. The panel is placed on the roof of the bicycle. It is connected to the battery via charge controller. It supplies enough voltage to store in the two 12V battery.
HARDWARE SETUP:
The solar tricycle was successfully developed as per the design for disabled community. This tricycle works on solar source and employs BLDC motor to drive the tricycle. The average and maximum speed was obtained as 10 kmph and 20 kmph respectively. Due to limited solar energy during cloudy/rainy days provision is made to charge the battery using external electric power source. The solar powered tricycle will be effective in providing mobility for persons who have disabilities. Various vehicles of same category available in India was compared for different parameter and it was concluded that solar tricycle as a complete blessing to the disabled community compared to other vehicles using various sources of energy.
FUTURE SCOPE:
Hybrid solar powered electric tricycle can be developed in which the battery is charged by manpower. Thus, it uses solar power as one of the energy sources. In future, wind can also be used as one of the energy sources by placing wind turbine at the convenient place. Even tricycle can be digitalized by fitting indicators, advanced sensors, navigation system etc. Gear variation system can also be implemented to increase torque and to control speed.

APPENDIX
#include LiquidCrystal lcd(2, 3, 4, 5, 6, 7); const int battery= A0; //
float battery_voltage=0; const int solar=A1; float solar_voltage=0; const int buzzer=8; long dist_value=0;
long dist_check() {
long duration, distance; digitalWrite(10,LOW); delayMicroseconds(2);
digitalWrite(10, HIGH); delayMicroseconds(10); digitalWrite(10, LOW);
duration = pulseIn(9, HIGH);
distance = duration * 340 / (2 * 10000); return distance;
}
void setup()
{
pinMode(10, OUTPUT); pinMode(9, INPUT); pinMode(buzzer, OUTPUT);
digitalWrite(buzzer, HIGH);delay(1000); digitalWrite(buzzer, LOW); lcd.begin(16, 2);

lcd.clear();
lcd.setCursor(0, 0); // Positions the cursor in the first column (0) and the firt row (1) at LCD

lcd.print(" SOLAR POWERED");
lcd.setCursor(0, 1); // Positions the cursor in the first column (0) and the firt row (1) at LCD
lcd.print(" ELECTRIC "); delay(2000);
lcd.clear();
lcd.setCursor(0, 0); // Positions the cursor in the first column (0) and the firt row (1) at LCD
lcd.print(" TRICYCLE FOR");
lcd.setCursor(0, 1); // Positions the cursor in the first column (0) and the firt row (1) at LCD
lcd.print(" PHYSICALLY "); delay(2000); lcd.clear();
lcd.setCursor(0, 0); // Positions the cursor in the first column (0) and the firt row (1) at LCD
lcd.print(" CHALLENGED ");
lcd.setCursor(0, 1); // Positions the cursor in the first column (0) and the firt row (1) at LCD
lcd.print(" PERSONS"); delay(2000);
}
void loop()
{
battery_voltage=analogRead(battery); battery_voltage=(battery_voltage/1023)*32.8; lcd.clear();
lcd.setCursor(0, 0); // Positions the cursor in the first column (0) and the firt row (1) at LCD
lcd.print(" BATTERY VOLTAGE");
lcd.setCursor(0, 1);
lcd.print(" "); lcd.print(battery_voltage); lcd.print(" V"); delay(2000); solar_voltage=analogRead(solar); solar_voltage=(solar_voltage/1023)*32.8;
lcd.clear();
lcd.setCursor(0, 0); // Positions the cursor in the first column (0) and the firt row (1) at LCD
lcd.print(" SOLAR VOLTAGE"); lcd.setCursor(0, 1);
lcd.print(" "); lcd.print(solar_voltage); lcd.print(" V"); delay(2000); dist_value=dist_check();
lcd.clear();
lcd.setCursor(0, 0); // Positions the cursor in the first column (0) and the firt row (1) at LCD
lcd.print(" BACK DISTANCE"); lcd.setCursor(0, 1);
lcd.print(" "); lcd.print(dist_value); lcd.print(" cm"); delay(2000); if(dist_value<=50)
{ digitalWrite(buzzer, HIGH); lcd.clear();
lcd.setCursor(0, 0); // Positions the cursor in the first column (0) and the firt row (1) at LCD
lcd.print(" BACK SIDE"); lcd.setCursor(0, 1);
lcd.print(" OBJECT DETECTED "); delay(2000);
}
else
{ digitalWrite(buzzer, LOW); lcd.clear();
lcd.setCursor(0, 0); // Positions the cursor in the first column (0) and the firt row (1) at LCD
lcd.print(" BACK SIDE"); lcd.setCursor(0, 1);
lcd.print(" NO OBJECT "); delay(2000);
}
}

REFERENCES
1. M. Reddi Sankar, T. Pushpaveni, V. Bhanu Prakash Reddy - “DESIGN AND DEVELOPMENT OF SOLAR ASSISTED BICYCLE”, International Journal of Scientific and Research Publications, Vol. 3, Issue 3, in March 2013
2. Abdulkadir Baba Hassan - “DESIGN AND FABRICATION OF A MOTORIZED PROTOTYPE TRICYCLE FOR THE DISABLE PERSONS”, IOSR Journal of Engineering, Vol. 2, Issue 5 in May 2012
3. N. Sasikumar, Dr.P.Jayasubramaniam - “SOLAR ENERGY SYSTEM IN INDIA”, IOSR Journal of Business and Management, Vol. 7, Issue 1 in Feb 2013
4. Satish Kumar Dwivedi, Deepak Kumar Yadav, Ashutosh Mishra, Madhusudan Jaiswal, Shrikant Singh, Sujeet Kumar, - “DESIGN AND FABRICATION OF A MOTORIZED TRICYCLE FOR PHYSICALLY CHALLENGED PERSONS”, International Journal of Engineering Science Invention, Volume 3 in April 2014
5. M. Pooja Iyer, G. Ravi Teja, V. Sitaram Prasad - “DESIGN AND FABRICATION OF SOLAR ELECTRIC SCOOTER”, International Journal of Research in Engineering and Science (IJRES), Volume 2, Issue 5 in May. 2014
6. Immanuel Alphonse, Dr.S.HosiminThilagar, F.Bright Singh - “DESIGN OF SOLAR POWERED BLDC MOTOR DRIVEN ELECTRIC VEHICLE”, International Journal Of Renewable Energy Research, Volume 2, No.3 in July 2012
7. Shuh Jing Ying, Stephen Sundarrao - “POWER ASSIST HAND TRICYCLE WITH BATTERY FOR DISABLED PERSONS”, International Journal of Advanced Technology in Engineering and Science, Volume 02, Issue No. 06 in June 2014
8. Arun Manohar Gurram, P.S.V Ramana Rao, Raghuveer Dontikurti - “SOLAR POWERED WHEEL CHAIR: MOBILITY FOR PHYSICALLY CHALLENGED”, International Journal of Current Engineering and Technology, Volume 2, No.1 in March 2012