Disturbance Observer Based Glocal Control of Mechatronics Systems: A Passivity Approach

DOB has been one of the most popular robust control tools. However, there is still lack of practical design techniques for DOB-based applications, particularly for complex systems. To overcome this challenge, we investigate in this paper the possibility of DOB-based glocal control for a class of multi-actuator mechatronics systems possessing passivity property. In the lower-layer, each actuator is provided a DOB that locally compensates the external disturbances and model uncertainties. There exists in the upper-layer a global controller that controls an aggregation signal from the lower-layer. The aggregation and distribution channels connecting the lower/upper-layers can be treated as a middle one. Utilizing passivity theory, we rigorously obtain a condition for the global/local controllers to guarantee the stability of the overall system. We further investigate the other role of the middle-layer: attaining additional global objectives by optimization of the aggregation/distribution vectors.