Solar Powered Smart Lawn Mower

Project Title

Solar Powered Smart Lawn Mower

Project Area of Specialization Electrical/Electronic EngineeringProject Summary

Rapid growth of technology creates opportunities for engineers and inventors to design high-tech tools and equipments that make our job comfortable and sophisticated. Advancements in the Renewable resources provide best solution of green energy to fulfill our energy requirements. It will help against the war of global warming. Due to less advancement in lawn mowers technology, there are still conventional fuel powered lawn mowers in practice. It also require physical human operator to move around the ground for grass cutting. A Solar Powered Smart Lawn Mower operates with minimum human effort using android app. Android app will allow the user to operate from long distance. This project considers the implementation of a machine which can be operated wirelessly from any comfortable place using Android app and WIFI. Every action of grass cutting machine is controlled by using android app and Raspberry Pi controller to maintain the Machine within the lawn. The most important aspect of this project is the use of solar energy to power the motors and other electrical components. That makes this project energy efficient and economical.

Project Objectives

1) Reduce human efforts by introducing advance technological methods.

2) Control of Lawn Mower throught WIFI using Android App.

3) Implementation of lawn mowing using smart controller like Raspberry Pi.

4) Powered through renewable energy sources. Solar energy will be used as primary source of energy in this project.

5) To obtain maximum power from solar panel using Maximum Power Point Tracking techniques in the solar charge controller.

6) Help aged or handycam persons that are unable to manage their lawns by their own.  

Project Implementation Method The implementation of this project is divided into two sections. 1) Hardware

                              In this project the Raspberry Pi will be used as a main controller. Raspberry Pi will be used to receive commands from the user and perform particular task on specific command. The built-in Wifi in the raspberry pi will be used to communicate between user and raspberry pi. Since there is no wifi hotspot or wifi sharing device in the raspberry pi, so home wifi router will be used to interlink between user and raspberry pi. In this project there are two different types of motors being used. Smart Lawn Mower is a four wheel vehicle. The properties of driving motors are different than cutting motor. Low RPM and High torque required for driving motor and high RPM and low torque required for cutting motor. In order to reduce the speed and increase the torque of driving motors we have used gears to ensure that the four motors are identical to each other. In the middle structure of lawn mower there is a single Brush Less Direct Current (BLDC) motor that is directly coupled with steel blades to chop grass. MPPT solar charge controller is implemented through Arduino Mega 2560. As there are some limitations of Raspberry Pi for analog read / write and also in PWM signal reading. One solar panel would be used to power the mower and charge a single 12V battery inside lawn mower. Battery makes sure that lawn mower also works during off-peak times and nights. Motor driver would also be designed by ourselves using transistor, logic gates and operational amplifiers. The properties of MOSFET, BJT all combined together to get maximum power from the motor driver and to ensure smooth operation. One 8 mega pixel camera would be connected to Rasperry Pi. The camera will provide live video feed to the user so user can operate mower while sitting on the couch.

2) Software  

                             Software section consists of softwares that are used to receive commands from the user and perform accordingly. The software section is further divided into two sections. 

1. Raspbery Pi Server.
2. Android App

In Raspberry Pi, Python language is used to program the GPIO pins of the Raspberry Pi. The program receives HTML request and compare it for further actions. Inside the program there would be six conditions as following.

• Forward.

                        When forward request is called through android the GPIO pins would receive on and off voltage signals in such a way that motors will operate in clock-wise direction.

• Reverse.

                         When reverse request is called the GPIO pins will change its order so that motors operate in anti clock-wise direction.

• Right

                     When right request is called the GPIO pins will change its order so that right side motors will operate in anti clock-wise direction and left side motors operate in clock-wise direction.

• Left

                  When left request is called the GPIO pins will change its order so that right side motors will operate in clock-wise direction and left side motors operate in anti clock-wise direction.

Benefits of the Project

This project would help aged and handycam people who are unable to maintain their lawns and gardens according to their requirments. Smart Lawn Mower will be more efficient and noise free as compared to the lawn mowers that are available in the market. The increasing cost of fuels and fuel emissions are alarming issue worldwide. This project will be a step forward for developing advance technologies to reduce global warming. There are some smart lawn mowers exist in the market with higher price tags which are not in the range of every person. This Lawn Mower will help to cutt down the cost of such lawn mowers and provide many benefits in low package such as control through mobile devices and use of solar energy.

Technical Details of Final Deliverable

Smart Lawn Mower is combined with two controllers Raspberry Pi as a main controller and Arduino Mega for MPPT solar charge controller. Arduino will be equipped with voltage sensors and current sensors on both battery side and solar side. The solar voltages are compared to the battery voltages and than gives a PWM signal to the buck converter that will adjust panel voltage to ensure maximum power from the panel. The previous value of voltage and current will be compared to the new one to get latest value for buck converter. PWM dutycycle will adjust the voltage of buck converter. Raspberry Pi will operate a server that allows the user to send command using Android App. Android App will be developed through app inventor placing some buttons to operate the mower and one button to ON/OFF the cutting motor. For each app button there will be a spectific code that will call IP address of the Raspberry Pi and Request a command to Raspberry Pi. The Raspberry Pi will respond to that request. For live video feed there will be a screen window in the application. Rest of the project details are discussed in project implementation section.

Final Deliverable of the Project HW/SW integrated systemCore Industry Energy Other Industries IT , Agriculture Core Technology RoboticsOther Technologies Internet of Things (IoT)Sustainable Development Goals Affordable and Clean Energy, Industry, Innovation and InfrastructureRequired Resources

Item Name	Type	No. of Units	Per Unit Cost (in Rs)	Total (in Rs)
			Total in (Rs)	70500
Raspberry Pi 4 model b	Equipment	1	15000	15000
Pi camera 8 mega pixel	Equipment	1	4000	4000
Solar Panel 60 watt	Equipment	1	5500	5500
12V maintenance free battery	Equipment	1	5500	5500
DC geared Motor	Equipment	4	2500	10000
BLDC motor	Equipment	1	1200	1200
ESC 30A	Equipment	1	1000	1000
Arduino Mega	Equipment	1	1500	1500
Motor Wheels	Equipment	4	800	3200
BMC 20A	Equipment	1	2000	2000
GPS module UBLOX	Equipment	1	1600	1600
GPS Antenna 1500 MHZ	Equipment	1	1600	1600
20*4 screens	Equipment	4	600	2400
PCB and fabrication	Equipment	6	500	3000
Body structure and design	Equipment	1	8000	8000
Licensing and other expenditure	Miscellaneous	1	5000	5000