Multibody Analysis and Control Synthesis of an Autonomous Unmanned Ground Vehicle Using Feedforward Braking Torques and Proportional-Derivative Feedback Controllers

In recent years, the realization of Unmanned Ground Vehicles (UGVs) has been gaining momentum thanks to rapid advances in new control technologies. In this vein, this study analyzed the dynamic behavior of a rover modeled in MATLAB using the SIMSCAPE MULTIBODY toolbox. Specifically, a new control strategy is introduced in this paper. The proposed control policy is based on evaluating breaking actions. Preliminarily, the braking torques of each wheel are calculated and compared with those of the plate in horizontal and different inclined plane configurations. Additionally, using cubic interpolation, four equal torques are applied to the four wheels. These feedforward torques start from zero and reach an average value, ensuring the vehicle moves within a specific range of ground inclinations. Due to internal mass imbalances and asymmetries in the multi-body model, various inaccuracies occur during simulation execution. Thus, feedforward control actions alone are not sufficient to move the UGV along a straight path. Therefore, a Proportional Derivative (PD) control strategy is chosen to solve this problem. By doing so, the numerical results from computer simulations accurately track the desired UGV trajectory.