Fuzzy Decentralized Sliding-Mode Control of a Car-Like Mobile Robot in Distributed Sensor-Network Spaces

In this paper, the trajectory tracking and (dynamic) obstacle avoidance of a car-like mobile robot (CLMR) within distributed sensor-network spaces via fuzzy decentralized sliding-mode control (FDSMC) is developed. To implement trajectory tracking and (dynamic) obstacle avoidance, two distributed charge-coupled device (CCD) cameras are set up to realize the dynamic position of the CLMR and the obstacle. Based on the control authority of these two CCD cameras, a suitable reference trajectory including desired steering angle and forward-backward velocity for the proposed controller of the CLMR is planned. It is also transmitted to the CLMR by a wireless module. The proposed FDSMC can track a reference trajectory without the requirement of a mathematical model. Only the input-output data pairs of the CLMR and the upper bound of its dynamics are required for the selection of suitable scaling factors. The proposed control system includes two processors with multiple sampling rates. One is a personal computer employed to obtain the image of the CLMR and the obstacle, to plan a reference trajectory for the CLMR, and then to transmit the planned reference trajectory to the CLMR. The other is a digital signal processor (DSP) implementing in the CLMR to control two dc motors. Finally, a sequence of experiments is carried out to confirm the performance of the proposed control system.