The seat suspension has a significant influence on riding comfort in many practical applications, such as heavy duty vehicles, military vehicles, and high-speed crafts. This paper proposes a seat suspension equipped with a variable equivalent inertance-variable damping (VEI–VD) device and a novel semi-active vibration control strategy. The VEI–VD device can control its equivalent inertance and damping by controlling two external resistors in its electric circuit. Especially, the VEI part of the device can store and release vibration energy via the inside flywheel, which enables the seat suspension to have a four-quadrant controllable capability in the available force–velocity diagram, similar to an active system. First, the dynamic model of the VEI–VD device is built, and a prototype is developed and tested to identify the model parameters and verify its characteristics. Then, a semi-active vibration control method is proposed for the VEI–VD seat suspension. The control metho
This article proposes a disturbance observer-based event-triggered H∞ controller for a semi-active seat suspension that equips an advanced electromagnetic damper (EMD) system. Automated driving is one of the leading technologies of the automotive industry. However, automated vehicles (AVs) may increase the incidence of motion sickness (MS) and deteriorate motion comfort. This article investigates a semi-active seat suspension system and an advanced controller to improve the motion comfort of AVs. The disturbance force of the seat suspension has considerable influence on the system dynamic, and applying a constant model to describe the real-time disturbance force is unreliable. Therefore, a disturbance observer is designed to estimate the seat suspension disturbance force, and it is used to compensate the controller. The Bouc-Wen model is selected to compare with the disturbance observer and validate its effectiveness. Then an event-triggered H∞ controller combined with the disturba
Recently, linear magnetorheological (MR) dampers have been widely utilised for impact protection of seat suspensions. However, the viscous force of the linear MR damper increases seriously with the increase of impact velocity. This results in a sharp increase of the total output force of the seat suspension, which may damage the suspension structure and lead to occupant injuries. To address this issue, the performance of a seat suspension installed with a rotary MR damper to improve the impact protection performance is investigated in this paper. Specifically, the mathematical models for the linear MR seat suspension and the rotary MR seat suspension are established. The impact protection performance of these two suspensions are numerically compared by the transient analysis and the dynamic impact simulation. Both the transient analysis and the dynamic simulation indicate that the rotary MR damper seat suspension is less sensitive to the impact velocity and can provide better impact pr
Abstract
This paper proposes a hybrid controller for a seat suspension equipped with an advanced electromagnetic damper (EMD) system to meet the requirement with vibration isolation and energy saving. The friction of seat suspension has considerable influence on the system dynamic. Applying a constant model to describe the friction is unreliable due to the long term wear and tear. Therefore, an observer is designed to estimate seat suspension friction, and it is used to compensate for the frictional influence in a H controller. The friction observer applies the acceleration, relative displacement and circuit current, which are measurable in engineering. Then, a hybrid controller is further proposed, in which the low-frequency vibration is controlled with the friction observer-based H controller, and the system will switch to passive state with low damping at high frequency based on the dominant frequency of the vibration. In order to validate the effectiveness of the proposed fric
An event-triggered H controller is designed for an active seat suspension in this paper, where the continuous event-trigger scheme is applied to transfer the dynamic system states to the controller only at event-triggered time instants. Delay-dependent stability criteria in the form of linear matrix inequality (LMI) are presented to guarantee the asymptotic stability of the seat suspension system. One Lyapunov function is chosen where some matrices are introduced with relaxed conditions. Two tight inequalities are applied to prove the positive definiteness of the Lyapunov function and stability of the system, which reduces the conservatism of the system for the time delay to the controller. The proposed control method can reduce the workload of data transmission of the seat suspension system and work as a filter to remove the effect of noise, so it can decrease the precision requirement of the actuator, which can help to reduce the cost of the seat suspension. Both simulation and expe