Simulation and disturbance estimation of speed-controlled mechatronic drive systems

Abstract

In the field of modern production systems, the process-parallel measurement of time-varying process forces and torques for high-level process monitoring is becoming increasingly important. Commonly utilized methods are based on additional sensors placed close to the working area. Unfortunately, this often leads to a higher complexity and additional costs due to the necessity of external hardware. An alternative approach is to evaluate the already available machine-internal signals of the subordinate drive systems. The process forces act on the load side of the machine axes in the form of disturbance forces and influence the drive-internal signals such as motor current or motor speed. To extract these disturbances, additional superimposed forces (e.g. friction and acceleration forces) and the influence of the feedback control as well as the mechanical system must be considered. Therefore, in the present paper, the application of various observer-based approaches for the estimation of load side disturbances on speed- controlled mechatronic drive systems will be examined. The investigations are performed on a simulation model of a speed-controlled machine axis. After an introduction, three different disturbance observers will be presented. Subsequently, the paper describes the structure of the simulation model including its parameterization based on test rig measurements. Afterwards, the performance of the disturbance observers will be investigated and compared taking selected influencing factors like changing controller and inertia parameters into account. The paper closes with a summary and an outlook.