A Unified Framework for the Study of Anti-Windup Designs

We present a unified framework for the study of linear time-invariant (LTI) systems subject to control input nonlinearities. The framework is based on the following two-step design paradigm: "Design the linear controller ignoring control input nonlinearities and then add anti-windup bumpless transfer (AWBT) compensation to minimize the adverse eflects of any control input nonlinearities on closed loop performance". The resulting AWBT compensation is applicable to multivariable controllers of arbitrary structure and order. All known LTI anti-windup and/or bumpless transfer compensation schemes are shown to be special cases of this framework. It is shown how this framework can handle standard issues such as the analysis of stability and performance with or without uncertainties in the plant model. The actual analysis of stability and performance, and robustness issues are problems in their own right and hence not detailed here. The main result is the unification of existing schemes for AWBT compensation under a general framework

Observer-based anti-windup compensator design for saturated control systems using an LMI approach

AbstractIn practical control systems, actuator saturation usually induces a windup phenomenon and potentially results in system instability. Accordingly, this paper develops an observer-based auxiliary anti-windup compensation scheme to mitigate the effects of actuator limitations on the performance and stability of the controlled system. In the proposed approach, the controller output signal passing through the saturation element is treated as an external disturbance imported to the designed controller and an auxiliary controller is designed to minimize the difference between the controller output signal and the system input signal. The conditions required to maintain the system performance in the presence of actuator saturation are formulated as an LMI criterion. The L2-stability criterion of the anti-windup compensator design is also formulated as an LMI condition. It is shown that by integrating the two LMI conditions and solving the resulting optimization problem, the resulting anti-windup controller both minimizes the performance attenuation of the saturated control system and guarantees its L2-stability

ANTI-WINDUP COMPENSATOR SYNTHESIS FOR SYSTEMS WITH SATURATION ACTUATORS

Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/57796/1/Anti-WindupCompensatorSynthesisforSystemswithSaturationActuators.pd

Adaptive control with convex saturation constraints

Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/166259/1/cth21096.pd

Design of a 4D Trajectory Tracking Controller with Anti-Windup Protection for Fixed-Wing Aircraft

23rd International Conference on System Theory, Control and Computing, ICSTCC (2019: Sinaia; Romania)This work contains the design and test of a control scheme for a fixed-wing aircraft to track 4-dimensional waypoints. The controller scheme is a multi-loop design that consists of an inner controller synthesized with the h-infinity loop-shaping method and an outer controller synthesized with the PID method. Multiple inner-loop controllers are synthesized in a state-machine configuration as a measure against saturation windup. © 2019 IEEE