Fully Automatic Solar Grass Cutter

Project Title

Fully Automatic Solar Grass Cutter

Project Area of Specialization RoboticsProject Summary

The project "Fully Automatic Solar Grass cutter" has a capability of cutting grass of grassy lawns & grounds without or minimum human interference within a defined boundary. It uses solar energy as a source of power. Solar energy is continuously being stored in battery by passing through charge controller so that required amount of power could be supplied continuously and power can be provided in case of cloudy weather.

WORKING:

When solar grass cutter is turned on, left ultra-sonic sensor checks the distance from boundary and decide that first turn will be left or right. It moves forward. When front ultra-sonic sensor detect boundary in front of it, solar grass cutter takes consecutive two turns in same direction as decided by left sensor in start of grass cutting so that well defined pattern can be followed. Accurate turns are calculated by using encoder. Again it moves forward and if again boundary is detected by front sensor then again it takes turn but these two consecutive turns will be in opposite direction  to the previous turns taken by grass cutter and solar grass cutter will continue in the same manner .

1. Battery is used to power up all sensors ,motors driver circuits(H-bridge) ,microcontroller and motors.
2. Ultra-sonic sensors are used  to detect boundary and objects within its path so that it can change its course in defined directions as per instructions of forward, left and right ultra-sonic sensors given to micro-controller (Arduino).
3. L298N motor driver circuits(H-bridge) are used to control the direction ,speed and directions of 4 DC motors in the base of structure.
4. cutter motor is mounted in front which is 12V DC operated and its switching(ON/OFF) is controlled by micro-controller
5. Micro-controller is used to give instructions to motor driver circuits to change the direction and movements according to data received from sensors. It is also responsible for switching (ON/OFF) of grass cutting motor. It acts as main brain of solar grass cutter.
6. Solar panel is used as power source.
7. Solar Charge Controller is used to provide required amount of voltages and current to battery for storage otherwise pulsating DC supply coming from panel can burn out the components if attached directly.
8. Encoders are used to decide how much RPMs of base motors are required to take accurate turns to follow symmetrical pattern  in field.

Project Objectives

The main objective of this project "Fully automatic Solar Grass Cutter" is to provide a system or a prototype that  :

1. Is energy efficient .
2. Is with minimum or no human interference/effort.
3. Is with no air pollution.
4. Is with no environmental pollution i.e. Noise.
5. Is with less labor cost.
6. No fuel consumption

Project Implementation Method

There are three circuit interfacings in this project "Fully Automatic Solar Grass Cutter".

1. Cutting Motor Circuit
2. Base Motors Circuit
3. Ultrasonic Sensors Circuit

The main Brain of whole project is micro-controller (Arduino Mega 2560).All circuits are interfaced with micro-controller. Micro-controller is programmed to check different cases fed into it.

• Cutting Motor Circuit: It consist of 2 sharp blades mounted at the tip of 12V DC motor's( High RPMs) shaft. FET switch is used to control speed and switching of motor. Motor is directly connected to FET switch and battery. Battery provides 12 volt Dc supply to motors and FET gives Controlled signal from micro- controller to  turn it ON/OFF and for speed control of motor.
• Base motors circuit: It consists of two L298N motor driver circuits that control the speed of base motors and direction in which it wants to take turn. It is given power from battery and pulse/controlled signal from micro-controller. It also gives 12V supply to motors taking from battery.
• Ultrasonic Sensors Circuit: Three ultra-sonic sensors are mounted on the robot 1 in each direction i.e. front, left and right to check the distance from the boundary and to decide a  turn ultra-sonic sensors are interfaced directly with micro-controller which checks the distance at regular intervals for proper positioning of robot in field

All these circuits are interfaced with micro-controller(Arduino Mega 2560).

When solar grass cutter is turned on, left ultra-sonic sensor checks the distance from boundary and decide that first turn will be left or right. It moves forward. When front ultra-sonic sensor detect boundary in front of it, solar grass cutter takes consecutive two turns in same direction as decided by left sensor in start of grass cutting so that well defined pattern can be followed. Accurate turns are calculated by using encoder. Again it moves forward and if again boundary is detected by front sensor then again it takes turn but these two consecutive turns will be in opposite direction  to the previous turns taken by grass cutter and solar grass cutter will continue in the same manner .When the value of 2 sensors will be high it means the corner is detected so the robot will stop.

Benefits of the Project

This project "Fully Automatic Solar Grass Cutter" is beneficial in ways that it:

1. Requires minimum or no human interference.
2. Is designed to mow those lawns where bulky cutters are not effective.
3. Has minimum running cost.
4. Is easy to program as per requirement of user.
5. Is pollution free robot.

Technical Details of Final Deliverable

Technical specifications of this proposed project "Fully Automatic Solar Grass Cutter" are as follow:

NAMES	SPECIFICATIONS
Solar Panel	18volt, 0.83Amp, 15Watt
Battery	12Volt, 5AH ,60 Watt
Solar Charge Controller	10 Amp(max), DY-002(model)
DC Gear Motors (for base movements)	12Volt, 1.5 Amp, 18Watt (high torque)
DC Gearless Motor (for cutting)	12Volt, 1.6Amp,19.2 Watt (low torque)
Micro-controller(Arduino Mega)	5Volts, 200 mA
Ultra-sonic Sensors	HC-SR04
Motor Driver (H-bridge)	L298N

NAMESSolar Panel    BatterySolar Charge Controller      DC Gear Motors (for base movements)DC Gearless Motor (for cutting)Micro-controller(Arduino Mega)Ultra-sonic SensorsMotor Driver (H-bridge)Final Deliverable of the Project HW/SW integrated systemType of Industry Energy , Others Technologies Robotics, Clean TechSustainable Development Goals Affordable and Clean EnergyRequired Resources

Elapsed time in (days or weeks or month or quarter) since start of the project	Milestone	Deliverable
Month 1	Literature Review	Yes
Month 2	Software Simulation	Yes
Month 3	Equipments Selection	Yes
Month 4	Arduino Coding	Yes
Month 5	Robotic Hardware Design	Yes
Month 6	Interfacing &Itegrating of circuits	Yes
Month 7	Alignment & path following with accurate turns	Yes
Month 8	Testing & Verifying Results	yes