Regulatorer med styrsignalsbegränsning

• Main Author: Stenberg, Conny
• Format: Others
• Language: Swedish
• Published: Linköpings universitet, Institutionen för systemteknik 2003
• Subjects: Reglerteknik; saturation; input constraint; windup; anti-windup; MPC; Automatic control
• Online Access: http://urn.kb.se/resolve?urn=urn:nbn:se:liu:diva-1796

This thesis studies the negative impact that control signal saturation may have on a controlled system. Different methods that are used to compensate for this problem are also studied and evaluated. Both sensitivity to disturbances and the effect the method has on the systems'ability to follow a reference signal will be examined. Stability will be discussed, but no conclusions whether the systems are stabilized or not can be drawn. Control signal saturation will lead to a slower behavior in general. For controllers with integral action this performance degradation will cause an extended growth in the integrating part of the controller. This leads to large overshoots and possibly to instability. As an alternative to the more ad-hoc based methods, model based predictive control is studied. This metod can explicitly handle constrained control signals. Here, too, sensitivity to disturbances and the effect the method has on the systems'ability to follow a reference signal is examined.