Speed tracking control of in-wheel motor for small scale tracked vehicle

Generally, tracked vehicles are used on the ground for rough terrain swamp and snow field that a wheeled vehicle cannot go through. In this study, the basic control structure of the tracked vehicle system is developed based on a validated 3 degree-of-freedoms (DOF). The model is to control the turning radius capability of the vehicle in terms of vehicle speed, longitudinal, lateral and yaw motions. PID control is used to control the vehicle and optimized using Particle Swarm Optimization (PSO) algorithm. In order to verify the developed model, it is set to turn in 20 m radius with various speeds which are 10 km/h, 20 km/h and 30 km/h. The performance of PID control structure without optimization is compared to the performance of PID control structure optimized using PSO algorithm with respect to the desired travelling conditions. From the simulation results, it can be seen that the performance of optimized control structure is better compared with non-optimized control structure in terms of vehicle speed, longitudinal, lateral and yaw motions. From the simulation results, it also can be observed that the proposed tracked control structure with PID control is able to increase the performance of the tracked vehicle under medium speed at 20 km/h with maximum percentage of improvement 55%, 69%, 68% for longitudinal displacement, lateral displacement, and yaw angle respectively. Finally, tracked vehicle system with PID controller optimized by PSO is then tested experimentally through Hardware-in-the-Loop Simulation (HiLS) using an actuator namely in-wheel motor system. From the experimental results, a good agreement between HiLS and simulation is obtained with 14%, 19%, 18% and 9% in error reduction for longitudinal displacement, lateral displacement, and yaw motion respectively. It also indicates that the proposed control structure with PID controller optimized by PSO was proven to reduce the error by giving the desired speed and turning radius to maintain the desired direction of the vehicle during maneuvering.