Control of a path following caterpillar robot based on a sliding mode variable structure algorithm

Abstract

Tracked plant protection robots operating in soft, sticky soil and complex environments such as during the middle and late stages of maize cultivation can deviate significantly from their desired path. A path following control algorithm of for a tracked robot based on a sliding mode variable structure algorithm and the control system was developed. A dynamic model of the interaction between tracked chassis and soil underneath using specific fluctuation characteristics and soft soil conditions was established using multi-body dynamic simulation software. The control system was developed in MATLAB/Simulink and a joint simulation test is carried out. The simulation results show that the sliding mode variable structure algorithm could achieve better control. Field tests were carried out and the results showed that the maximum path deviation for the tracked robot using control based the algorithm was 70 mm, and the average path deviation was 30 mm. There were no out-of-control phenomena. The robot was able to carry out effective late season plant protection operations among the maize rows realising human-machine separation and environmental prevention and control.