A Coupling Active Disturbance Rejection Control for Multi-variable Systems with Upper/Lower Triangular Input Matrix

The accuracy of the mathematical model of a multi-variable system has a significant influence on the control law design. To reduce the dependence on the accuracy of the plant model, a coupling control approach is proposed for multi-variable systems with upper/lower triangular input matrix based on linear active disturbance rejection control idea. The dynamics, of the controlled variable with only one control input, is established as a single-input single-output system, then this control signal is solved by the regular linear active disturbance rejection control; the other dynamics, of the controlled variables with more than one control input, are respectively established as individual multi-input single-output system, then these control signals are solved by the proposed multi-input linear active disturbance rejection control. The approach is employed to an aircraft lateral control. The simulation shows that the proposed approach provides good control performance and strong robustness for multi-variable coupling plant.