基于自适应滑模的多螺旋桨浮空器容错控制

Fault-tolerant control for a multi-propeller airship based on adaptive sliding mode method

  • 摘要: 针对多螺旋桨浮空器执行机构易发生故障的容错控制问题,同时考虑系统所受到的未知外部扰动和螺旋桨输入幅值的饱和约束,提出一种自适应滑模容错控制方法。建立浮空器的四自由度运动模型,系统分析矢量螺旋桨的故障类型,分为输出力的大小故障和矢量转角故障,得到浮空器执行机构的故障模型。基于自适应和滑模控制理论,由跟踪目标与系统当前状态偏差设计积分滑模面。针对未知外部扰动和执行机构偏移故障,设计相应的自适应律进行处理;针对螺旋桨输入饱和约束,应用Sigmoid函数设计跟踪轨迹进行处理。由此设计一种自适应滑模容错控制策略,利用Lyapunov稳定性理论证明了闭环系统的全局渐近稳定性能。以上海交通大学的多螺旋桨浮空器为模型,仿真验证了故障容错控制方法的有效性和鲁棒性。

     

    Abstract: An airship is a kind of light-than-air vehicle, which is composed of a gas-filled cyst body and a propulsion system. The airship mainly flies in near-space, and because of the exposure to the lower temperature, solar radiation and long-term operation, it is difficult to avoid failure. Therefore, how to solve the failures of the airship and increase its safety has been a significant topic. The recent research on a fault-tolerant control system can be divided into two parts, active and passive fault-tolerant control. The active fault-tolerant control system requires a fault detection module to obtain the fault information, and then the reconfiguration control law will be reconstructed by the fault-tolerant control module. In this way, the design of the controller is very complicated and the parameters are more difficult to adjust. The passive fault-tolerant control develops a control system based on robust theory without changing the controller and system structure, which doesn’t need the fault information. In this paper, an adaptive sliding mode controller (ASMFTC) was developed for multi-propeller airship with the faults of actuators, where the external wind disturbances and control input saturation were also considered. A four-DOF dynamic model of the airship was established, and the novel fault model of the vectored propellers was designed. The fault system model of the multi-propeller airship was then built. Based on the sliding mode control theory, an integral sliding surface was presented with the residue between the trajectory and states of the airship, in order to deal with the problems of the offset faults and external disturbances, the adaptive law was designed. Thus, an adaptive sliding mode fault-tolerant control controller was proposed. The global asymptotic stability of the system is guaranteed by Lyapunov theory. The effectiveness and robustness of the controller are demonstrated by simulation results of a multi-propeller airship designed by Shanghai Jiao Tong University.

     

/

返回文章
返回