基于摩擦补偿和自抗扰的惯导测试转台复合控制

Compound Control of an Inertial Navigation Test Turntable Based on Friction Compensation and Active Disturbance Rejection Control

惯导测试转台轴系间的非线性摩擦力矩会降低系统的角分辨率和重复精度,系统运行过程中的模型参数变化会严重影响系统的跟踪精度,针对该问题提出一种基于摩擦补偿和自抗扰控制的复合控制方案。首先建立测试转台的数学模型,采用LS算法辨识Stribeck摩擦模型,将其作为前馈补偿加入控制中,以减小摩擦对测试转台的影响。为了降低对摩擦的过补偿、欠补偿和系统模型失配等其他干扰的影响,进一步设计了测试转台的自抗扰控制器,利用跟踪微分器对系统的参考输出进行轨迹规划,应用扩张状态观测器对系统的输出进行状态和扰动估计,通过非线性状态误差反馈控制律对系统广义误差进行控制。仿真和实验结果表明,该复合控制方案可提高测试转台伺服控制单元的抗干扰性能和鲁棒性,取得较好的控制效果。

Nonlinear friction torque between shafts of the inertial navigation test turntable may reduce angular resolution and repeated precision,and the variation of model parameters also has a great influence on tracking precision.A compound control based on friction compensation and active disturbance rejection control(ADRC)is proposed to reduce such influences.Firstly,the mathematical model of a test turntable is established,and a least square method is adopted to identify the Stribeck nonlinear friction model which is used as a feed forward compensation to reduce the interference of friction.In order to reduce other interference factors such as over compensation,under compensation and system model mismatch,etc,an ADRC is designed in additional.Tracking differentiator(TD)is used to track the reference output,extended state observer(ESO)is used to estimate the state and disturbance of the system output,and nonlinear state error feedback law(NLSEFL)is used to control the generalized error of the system.Simulation and experimental results show that the proposed compound controller achieves good control effect which can enhance the disturbance rejection property and robustness of the servo control unit of the test turntable.