Applications of the unsteady vortex-lattice method in aircraft aeroelasticity and flight dynamics

This survey paper aims to provide some insight into the design of suspension control system within the context of existing literature and share observations on current hardware implementation of active and semi-active suspension systems. It reviews the performance envelop of active, semi-active, and passive suspensions with a focus on linear quadratic-based optimisation including a specific example. The paper further discusses various design aspects including other design techniques, the decoupling of load and road disturbances, the decoupling of pitch and heave modes, the use of an inerter as an additional design element, and the application of preview. Various production and near production suspension systems were examined and described according to the features they offer, including self-levelling, variable damping, variable geometry, and anti-roll damping and stiffness. The lessons learned from these analytical insights and related hardware implementations are valuable and can be applied towards future active or semi-active suspension design.

State of the art survey: active and semi-active suspension control

The problem considered in this paper is the design and analysis of control strategies for semiactive suspensions in road vehicles. The most commonly used control algorithm is the well-known sky-hook (SH) damping. Recently, a new control approach named acceleration driven damping (ADD) has been developed, using optimal-control theory. It has been shown that SH and ADD have complementary characteristics: SH provides large benefits around the body resonance; otherwise performs similarly to a passive suspension; instead, ADD provides large benefits beyond the body resonance. The first goal of this paper is to show that-in their specific frequency domains-SH and ADD provide quasi-optimal performances, namely, that it is impossible to achieve (with the same semi-active shock-absorber) better performances. This result has been obtained using the framework of the optimal predictive control, assuming full knowledge of the disturbance. This result is very interesting since it provides a lower-bound to semi-active suspension performances. The second goal of the paper is to develop a control algorithm which is able to mix the SH and ADD performances. This algorithm is surprisingly simple and provides quasi-optimal performances.

Mixed Sky-Hook and ADD: Approaching the Filtering Limits of a Semi-Active Suspension

The problem considered in this paper is the design and analysis of control strategies for semiactive suspensions in road vehicles. The most commonly used control framework is the well-known Sky-Hook (SH) damping. Two-state or linear approximation of the SH concept are typically implemented. The goal of this paper is to analyze the optimality of SH-based control algorithms, and to propose an innovative control strategy, named Acceleration-Driven-Damper (ADD) control. It is shown that ADD is optimal in the sense that it minimizes the vertical body acceleration (comfort objective) when no road-preview is available. This control strategy is extremely simple; it requires the same sensors of the SH algorithms, and a simple two-state controllable damper. In order to assess and to compare the closed-loop performance of the SH and ADD control strategies, both a theoretical and a numerical analysis of performance are proposed.

Acceleration-Driven-Damper (ADD): An Optimal Control Algorithm For Comfort-Oriented Semiactive Suspensions

https://hal.archives-ouvertes.fr/hal-00733261/document

Survey and performance evaluation on some automotive semi-active suspension control methods: A comparative study on a single-corner model

SUMMARY This paper deals with the novel control concept, so called ground-hook for active and mainly semi-active suspension of vehicles with the ultimate objective to minimize the tyre-road forces and thus the road damage. The basic ground-hook concept is extended to the several variants which enable to decrease criteria of road damage as well as to increase driver's comfort for a broad range of road unevennesses. Parameters of control law are determined by the parameter optimization for generally nonlinear model. The influence and interaction of the damping rate limits and time constants of variable shock absorbers are also taken into account. The influence of implementation of more complicated truck models is also discussed.

Extended Ground-Hook - New Concept of Semi-Active Control of Truck's Suspension

Development of semi-active road-friendly truck suspensions

Vibration Control of MR-Damped Vehicle Suspension System Using PID Controller Tuned by Particle Swarm Optimization

The paper deals with the design and control of an example of redundantly actuated parallel kinematic structure that can be a machine tool. The principle of redundant actuation brings parallel kinematic structures which do not have singular positions in workspace and which has increased dynamic, stiffness and accuracy properties. There is proposed a parallel kinematic structure called Sliding Star that has promising dynamic and stiffness properties. The conceptual design-by-optimization of this structure is briefly described. The redundantly actuated parallel kinematics have control problem due to mutual fighting of redundant drives. There is described the solution of this problem. Based on the investigated redundantly actuated parallel kinematics there has been built a laboratory prototype. The experimental results from the control of this prototype are briefly presented.

Design-by-Optimization and Control of Redundantly Actuated Parallel Kinematics Sliding Star

This paper presents the modelling of heavy duty vehicle prototype for a semi-active suspension design. Two basic models have been developed - the model of a passive vehicle and the model of a vehicle equipped with controllable shock absorbers. The models serve for evaluation of several proposed control schemes. The identification and verification experiments, which has been provided on the truck are described as well as the software tools used in the process of simulation.

Zbyněk Šika

Papers

Extended Ground-Hook - New Concept of Semi-Active Control of Truck's Suspension

Development of semi-active road-friendly truck suspensions

Vibration Control of MR-Damped Vehicle Suspension System Using PID Controller Tuned by Particle Swarm Optimization

Design-by-Optimization and Control of Redundantly Actuated Parallel Kinematics Sliding Star

Dynamic model of truck for suspension control