The stability analysis is studied for $H_{\infty } $ controlled networked active quarter-vehicle suspension systems with a resilient event-triggered scheme (RETS) under periodic denial-of-service (DoS) jamming attacks in this article. For the networked suspension system, the system-state signals are measured by sensors and transmitted to the cloud controller through a wireless network and then the control signal is transferred to the actuator to control it. An event-triggered scheme (ETS) is designed to reduce the workload of data transmission, which is effective to select some most useful information to transmit and discard some redundant data. DoS attacks can block the data transmission when it is active, so a resilient event-triggered $H_{\infty } $ control method is built based on the Lyapunov stability theory. The exponential stability of the controlled suspension system, as well as the $H_{\infty } $ performance, is analyzed in this article. Some simulation results show that the proposed control method is effective to improve driving comfort and driving safety and reduce the workload of data transmission under periodic DoS attacks.

The output‐feedback event‐triggered $H_{\infty }$ controller is designed in this paper for singular active seat suspension systems. The human body is simply separated into two parts (body torso and head) and is considered with the seat suspension system. The accelerations of each part are considered as part of the system states, which makes the system as a singular system. The seat suspension deflection, relative velocity, the accelerations of the seat frame, body torso, and head are defined as the system outputs, which are all measurable in real‐time. The output‐feedback $H_{\infty }$ controller is designed at first. Then, the event‐triggered scheme is designed for the seat suspension system to reduce data transmission. Linear matrix equalities criteria are presented to get the controller and event‐triggered scheme and ensure the admissibility of the seat suspension system. Simulation results are shown to illustrate the effectiveness of the considered control method.

Overshoot and long settling time are two common problems of the positioning control for robotic arms. To solve the positioning control problems, an innovative variable stiffness and variable damping (VSVD) magnetorheological (MR) actuation system for robotic arms was designed, prototyped and evaluated in this paper. The system can reduce the overshoot and settling time of the robotic arm with less energy consumption by controlling the stiffness and damping of its VSVD unit. A robotic arm with the VSVD actuation system was developed and prototyped. In order to evaluate the performance of the system, a step route and a customised route were designed for the robotic arm system to trace. Under these two routes, the positioning control performances of the VSVD robotic arm were evaluated numerically and experimentally with the control modes of uncontrolled, VD, VS and VSVD, respectively. Both the numerical and experimental results demonstrated that the VSVD control mode works best in general with less overshoot, settling time and energy consumption, indicating that the proposed VSVD actuation system can serve as a good candidate to solve the positioning control problems of robotic arms.