Parameter Identification and Controller Design for the Velocity Loop in Motion Control Systems

Abstract

Today the controller commissioning of industrial used servo drives is usually realized in the frequency domain with the open-loop frequency response. In contrast to that the cascaded system of position loop, velocity loop and current loop, which is standard in industrial motion controllers, is described in literature by using parametric models. Several tuning rules in the time domain are applicable on the basis of these parametric descriptions. In order to benefit from the variety of tuning rules an identification method in the time domain is required. The paper presents a method for the identification of plant parameters in the time domain. The approach is based on the auto relay feedback experiment by Åström/ Hägglund and a modified technique of gradual pole compensation. The paper presents the theoretical description as well as the implementtation as an automatic application in the motion control system SIMOTION. The identification results as well as the achievable performance on a test rig with a PI velocity controller will be presented

Improved Controller Performance for Electromechanical Axes

“…Combined with a suitable tuning rule, controller parameters can be computed automatically. For the special requirements of drive control with comparatively small lag times and significant dead times, the RFB was adapted by applying the successive pole placement method [5]. The method is intended to be utilized in the commissioning phase of the machine, since the linear controller (G R (s)) has to be replaced by a non-linear relay element (Fig.…”

“…The target value (J tot = 0,001355 kgm 2 ) is identified well for various speed levels, if a lower boundary for the given hysteresis of 10 % to 20 % is not violated. More details about the approach, along with further experimental results, controller tuning examples and applications to different control loops of the cascade structures can be found in [4] and [5].…”