Dynamically constraint aware based fault tolerant control strategy for vehicle active suspension systems

To address vehicle instability induced by active suspension actuator failures, a Dynamically Constraint-Aware based Fault-Tolerant Control (DCA-FTC) strategy is proposed to enhance the reliability of suspension systems under faulty conditions. The key idea is a force-constraint reconstruction method that maps the residual actuation capabilities of degraded actuators into vehicle body force space, ensuring that the upper-layer control demands can be realised by the degraded actuators. Specifically, a hierarchical control architecture is adopted, in which, under the reconstructed force constraints, the body layer computes the optimal body-level control forces by incorporating the predicted roll moment information, the force-allocation layer distributes the body-level control forces into target forces for individual suspensions according to their health states, and the execution layer generates the corresponding actuator force commands to track these targets. Simulation results demonstrate that, compared with LQR-based suspension controllers, under multi-actuator partial failure conditions, the proposed DCA-FTC reduces the RMS values of body heave acceleration, pitch angular acceleration, and roll angular acceleration by 11.66%, 55.52%, and 77.92%, respectively. Furthermore, under single-actuator complete failure conditions, DCA-FTC reduces the RMS values of pitch and roll angular accelerations by 56.86% and 92.34%, respectively, while guaranteeing that the control forces remain within the feasible domain.