Autonomous Greenhouse Vehicle
Three
different people have worked on this project. The project was started
in 2002.A custom designed skid steering vehicle was developed to the
specifications of navigating greenhouse alleys carrying 100kg of liquid
pesticide on a dirt surface with 15 degree gradient. The vehicle had a
zero turning radius. The vehicle was intially fitted with ultrasonic
sensors to keep the vehicle in the path. Fuzzy logic control was used
on a microcontroller to control the vehicle's turn and speed. (
Vijay
took over this project in 2004. It was then found that ultrasonic
sensors used where not sufficient to operate reliably while making
large turns in the greenhouse. Therefore, ultrasonic sensors were
replaced with a video camera. Vision programs were developed and run on
a small industrial PC mounted on the vehicle. The vision algorithm
segmented greenhouse tables and the alley and calculated the lateral
position of the vehicle in the path. A PID controller was implemented
to control the vehicle's turn and speed. The vehicle was now able to
navigate the alleys between tables in a greenhouse environment while
also making large turns. A laser radar was later added to provide range
information. (