Constrained active suspension control via nonlinear feedback technology

In the above chapters, the linear quarter-car active suspension systems are studied based on H _∞ control approach over both entire frequency domain and finite frequency domain. For half-car model and full-car model, however, the vehicle suspensions are no longer easily simplified as linear systems, but nonlinear ones, because of the nonlinear characteristics of suspension components and the coupling between subsystems. As a consequence, some nonlinear control methods should be put forward to tackle the problem. In Sect. 4.1, terminal slide mode control is applied to realize finite time-stabilization which ensures that the tracking errors reach zero in finite time. Meanwhile, the singularity and chattering problems are resolved, and robustness and disturbance rejection properties of the system are good. In Sect. 4.2, when designing the adaptive backstepping controller, parameter uncertainties including spring nonlinearity and the piece-wise linear behavior of the damper are taken into consideration to form the basis of accurate control.