Output feedback control with H_∞ performance for saturated linear systems with magnitude and rate constraints

Abstract

The dynamic behaviour of controlled systems depend significantly on the allowable magnitude and change rate of the control efforts, which need to be considered during controller design. The controller design algorithm investigated in this paper can independently address both the magnitude and rate constraints and their effect on actuator dynamics. The integral dynamics are augmented to the systems actuator. The original control effort is formulated as new states in the augmented dynamics formulation, and the inputs of the integrator represent the rate of the control effort. The feedback gain is then designed to obtain suitable actuator dynamics such that the desired H∞ performance can be optimized and the magnitude of the rate constraints can be satisfied. Using satellite attitude control and aircraft longitudinal control as case studies, the effectiveness of the proposed algorithm is verified through achievable H∞ performance and time response simulations with various chosen constraints on the magnitude and rate of the control.

Synthesise of MPC controller for uncertain systems subject to input and output constraints: application to anthropomorphic robot arm

“…In the practice, control systems have constraints which can have damaging effects on system performances (Paulson et al, 2014). These constraints can be identified as actuator saturation, actuator magnitude and restrictions on output variables (Chen, 2010;Velosa, 2015).…”

“…In some cases, input and output constraints are often overlooked in the development of control laws. From a practical point of view, a control law without consideration constraints subsequently acting on the system such that long settling times, overshoots, and even cause instability (Chen et al, 2011;Valenzuela et al, 2013).…”

Proportional–integral–derivative attitude control subject to dynamic rate saturation of elevator through explicit command reshaping: An engineering approach

“…In Wang et al, 18 globally stable amplitude and rate saturation compensators were designed using linear matrix inequality (LMI) method with full state feedbacks. It should be noted that most of the reported schemes, including Lu 19 and Chen et al, 20 were conducted under the assumption of static rate saturation. 21 However, unlike the amplitude saturation, the rate saturation is a dynamic nonlinearity which is significantly influenced by the actuator performance.…”