ADRC-based Control of Pan-tilt System for Automated Vehicle Sensors

The environmental perception ability of automated vehicles is highly dependent on the measurement precision of on-board sensors, which may be influenced by vehicle vibration on rough roads. Thus, a pan-tilt servo system of the sensors is essential for disturbances compensation. This paper analyzed external disturbances of pan-tilt servo system via a road roughness model and a seven-DOF vehicle model. An Active Disturbance Rejection Control (ADRC) framework, which consists of extended state observer (ESO), tracking differentiator (TD), and nonlinear state error feedback (NLSEF) law, is established for the system control. In addition, the control parameters of ADRC are determined via experience and particle swarm optimization (PSO) jointly. Simulation results demonstrate that the proposed control method can effectively reduce the servo system response time while enhancing the system stability, compared with a traditional proportion control approach.