Control concepts with acceleration feedback for servo systems

Servo drives comprise a high dynamic and smooth motion control which is typically based on a cascaded control structure with position measurement or estimation. By including an additional acceleration feedback, especially the disturbance rejection as well as the speed droop can be improved significantly. Based on the proven cascaded control structure, this contribution presents three extended control concepts utilizing an additional acceleration feedback. All concepts are analytically optimized regarding their parameterization to improve the command as well as the disturbance responses. The proposed concepts are compared with each other by simulations and experimental results. Beside transient command and disturbance responses, the stationary speed droop is experimentally evaluated by determining the variance of the velocity at steady state conditions. For the experimental validation, a stiff mechanical system coupling two electrical synchronous motors, for the intended driving and emulated loading, and an acceleration sensor based on the Ferraris principle is used.