基于故障估计的无人车容错控制方法

Fault Estimation Based Fault-Tolerant Control Method for Unmanned Vehicle

考虑转向控制系统故障和未知干扰同时作用对无人车辆路径跟踪效果的影响,为提高无人车辆控制系统的可靠性,设计了一种无人车路径跟踪容错控制方法.对转向控制系统输入性故障进行分析,结合未知干扰情况定义了名义故障并建立相应的数学模型.利用高阶滑模观测器构造名义故障微分方程,并利用自适应容积卡尔曼滤波设计了车辆质心侧偏角和名义故障估计方法,从而为无人车容错控制提供可靠信息源.基于滑模控制理论设计了无人车路径跟踪容错控制器并证明了其收敛性.联合仿真和硬件在环试验结果表明,所提出的估计方法能够得到精确可靠的质心侧偏角和名义故障估计结果,且与无容错控制相比,所设计的路径跟踪容错控制器在面对故障和干扰时能够明显地提高车辆的控制性能,并同时保证车辆的路径跟踪能力及其自身的稳定性.

In order to improve the reliability of unmanned-vehicle control system,a fault-tolerant control method was proposed for unmanned vehicle path following,considering the influence of both steering control system fault and unknown disturbance on path-tracking effect of unmanned vehicle.Firstly,analyzing the input fault of steering control system and characterizing nominal fault from the unknown system interference,a mathematical model was established.And then,a differential equation of nominal fault was constructed with a high-order sliding mode observer,and the estimation method of vehicle sideslip angle and nominal fault was designed based on adaptive cubature Kalman filter,providing reliable information source for fault-tolerant control of unmanned vehicle.Finally,a fault-tolerant controller was designed based on sliding mode control method for path following of unmanned vehicle to prove its convergence.The results of co-simulation and hardware in the loop test show that,the proposed estimation method can get accurate and reliable estimation results of vehicle sideslip angle and nominal fault,and compared with no fault-tolerant control,the designed fault-tolerant path following controller can significantly improve the control performance of vehicle in the face of fault and interference,and at the same time ensure the path following ability and its own stability of vehicle.