基于自抗扰控制器的水下机器人姿态控制研究

Research on Attitude Control of Underwater Vehicles Based on Active Disturbance Rejection Controller

为了提高水下机器人在水中的轨迹跟踪精度,抵抗外部和内部干扰,提出了一种基于自抗扰控制技术的最优控制方法。首先,分别建立水下机器人运动模型和数学模型。其次,通过引入新的非线性函数,提高了扩张状态观测器的控制率和传统自抗扰控制的非线性误差反馈;通过改进的扩张状态观测器,将水下机器人姿态控制系统的非线性、模型不确定性和外部干扰扩展到一个新的状态。最后,采用改进的非线性状态误差反馈来抑制剩余误差,实现系统高质量控制。与PID控制和传统自抗扰控制相比,仿真和实验结果表明:改进的自抗扰控制具有超调量小、跟踪能力强和抗干扰能力强的特点。

For purpose of improving the trajectory-tracking accuracy of underwater vehicles in water and abilities of resisting external and internal disturbances,an optimal control method based on active disturbance rejection control(ADRC)technology was proposed.Firstly,the underwater vehicles’motion model and mathematical model were established,respectively;and then,through employing a new nonlinear function,both control rate of the extended state observer and the nonlinear error feedback of the traditional ADRC were improved,including making use of a modified extended state observer to have the nonlinearity,model uncertainty and the external disturbance of the AUV attitude control system extended to a new state and then implemented;finally,the improved nonlinear state error feedback was adopted to suppress any residual error and realize high-quality control for the system.Compared with PID control and traditional ADRC and through simulation and experiment,the results show that,the improved ADRC has the characteristics of small overshoot,strong tracking ability and anti-interference ability.