PID controller for velocity control and skid prevention for a six-wheeled rover

Mars rover should be able to maintain a constant speed while running, regardless of the terrain formation and surface's state. This article presents the use of a PID controller when controlling DC motors in a rover in order to obtain a constant angular velocity of each wheel. The rover was equipped with six hub wheels, each fitted with a DC motor including an encoder. The rocker-bogie suspension system presents a challenge when it comes to controlling the robot's traverse conditions. The drive system consists of the STM32 microcontroller controlling high-power motor diver of each engine. The implemented software receives a signal about the current change of position in the encoder, and on its basis the error to which our regulator is to respond is determined. After simulation and in-situ tests, the controller was developed based on carried out observation. Through the fine-tuning process of the regulator's output, we were able to achieve a calm ride at a constant speed on even in the most challenging terrain, as well as maintaining the position of the robot on steep hills.