Stability and Robustness of the Disturbance Observer-Based Motion Control Systems in Discrete-Time Domain
Stability and Robustness of the Disturbance Observer-Based Motion Control Systems in Discrete-Time Domain
复制标题
DOI：
10.1109/tmech.2020.3032115
复制
发表时间：
2020-10
期刊：
影响因子：
--
通讯作者：
E. Sariyildiz;Satoshi Hangai;T. Uzunović;T. Nozaki;K. Ohnishi
中科院分区：
文献类型：
--
作者：
E. Sariyildiz;Satoshi Hangai;T. Uzunović;T. Nozaki;K. Ohnishi
本文在离散时间域分析了基于扰动观测器的数字运动控制系统的鲁棒稳定性和性能。结果表明，数字运动控制器的相位裕度和鲁棒性可以直接通过调整标称对象模型和观测器的带宽来调整。然而，由于鲁棒稳定性和性能约束以及噪声敏感性，它们具有上界和下界。当通过测量伺服系统的不同状态来合成数字运动控制器时，DOb的设计参数上的约束发生变化。例如，当在数字鲁棒运动控制器合成中采用速度和位置测量时，DOb的带宽受到噪声灵敏度和水床效应的限制。当通过加速度测量来实现DOb时，由于水床效应而引起的鲁棒性约束被去除。利用离散时间广义Bode积分定理，推导了系统标称模型的设计约束条件和观测器的带宽。所提出的设计约束允许系统地合成一个高性能的基于DOB的数字鲁棒运动控制器。实验结果验证了所提出的分析和综合方法。
This article analyses the robust stability and performance of the disturbance observer (DOb) based digital motion control systems in the discrete-time domain. It is shown that the phase margin and the robustness of the digital motion controller can be directly adjusted by tuning the nominal plant model and the bandwidth of the observer. However, they have the upper and lower bounds due to robust stability and performance constraints as well as the noise sensitivity. The constraints on the design parameters of the DOb change when the digital motion controller is synthesized by measuring different states of a servosystem. For example, the bandwidth of the DOb is limited by the noise sensitivity and waterbed effect when the velocity and position measurements are employed in the digital robust motion controller synthesis. The robustness constraint due to the waterbed effect is removed when the DOb is implemented by acceleration measurement. The design constraints on the nominal plant model and the bandwidth of the observer are analytically derived by employing the generalized Bode integral theorem in discrete time. The proposed design constraints allow one to systematically synthesize a high-performance DOb-based digital robust motion controller. The experimental results are given to verify the proposed analysis and synthesis methods.