数字式惯性平台稳定回路的离散变结构控制

Discrete variable structure control of digital stabilization loop for inertial platform

为了实际实现具有良好跟踪精度和抗干扰能力的惯性平台稳定回路,建立了平台伺服电机的离散时间模型,设计了由单片机和高速DSP组成的数字控制系统,与惯性平台组成了基于采样数据的平台稳定控制回路,研究了离散变结构控制趋近律的选取方法,采用改进趋近律设计了离散变结构控制律,提出了一种数字式平台稳定回路的离散变结构控制方法,通过实物实验得出了平台伺服电机转轴摩擦力矩模型系数的估计值,并将其引入到控制系统中。仿真实验结果表明,该回路系统对于摩擦力矩和系统参数不确定性具有一定的抗干扰性能,对于阶跃干扰力矩输入具有良好的动态特性,且静态力矩刚度提高到1.2×104N·m/rad,系统对于斜坡和加速度输入信号实现了平稳跟踪,跟踪误差最大值分别为0.0056rad和0.0597rad。

In order to realize the stabilization loop of inertial platform with good tracking precision and strong anti-interference ability, the discrete model of the servo moment machine was established, and a system of single chip machine and DSP, which formed the digital stabilization loop with the inertial platform based on sampling data, was applied to realize the discrete variable structure control（DVSC） arithmetic. The DVSC reaching law was studied, and an improved reaching law was adopted to design the control rule. The initial model of the friction torque, which was established after the servo moment machine in the platform had been tested, was considered in the simulation experiment. The experiment result shows that the loop can greatly restraine the influence caused by the friction torque and the uncertainty of the parameters, and the torque sturdiness against the step influence torque is enhanced to 1.2×10^4 N·m/rad, where the tracking error is 0.0056 rad and 0.0597 rad respectively.