The Relative Performance Capabilities of Passive, Active and Semi-Active Car Suspension Systems

1986 ◽  
Vol 200 (3) ◽  
pp. 219-228 ◽  
Author(s):  
R S Sharp ◽  
S A Hassan
Keyword(s):  
Vehicle Speed ◽  
Active System ◽  
Control Laws ◽  
Active Systems ◽  
Suspension Systems ◽  
Working Space ◽  
Car Suspension ◽  
Road Surface Roughness ◽  
Good Set ◽  
Space Requirements

Based on the well-known quarter car representation of the automobile suspension design problem, pdomnce parameters relating to passenger discomfort, working space and tyre load variability are generated for passive, active and semi-active suspension systems. Active systems of two types having different hardware implications are considered, and linear optimal control theory is used in each case to derive a good set o control law parameters. The semi-active systems studied have control laws based on the fully active systems, but are capable only of dissipating energy, so that where the corresponding active system would be acting as an energy supply, the semi-active system switches off Practically realizable switching dynamics are assumed in the calculations. Results for all the systems, for one road surface roughness and vehicle speed, are generated in a form which allows comparison between systems of diffient types which have equal suspension working space requirements. The wider implications of the results are discussed, and far-reaching conclusions about the relative capabilities and design features of passive, active and semi-active systems are drawn.

Performance Predictions for a Pneumatic Active Car Suspension System

1988 ◽  
Vol 202 (4) ◽  
pp. 243-250 ◽  
Author(s):  
R S Sharp ◽  
J H Hassan
Keyword(s):  
Active Control ◽  
Suspension System ◽  
Low Frequencies ◽  
Control Laws ◽  
Suspension Parameters ◽  
Car Suspension ◽  
Road Roughness ◽  
Performance Predictions ◽  
Set Up ◽  
Space Requirements

A mathematical model of a pneumatic active car suspension system in a single wheel station form excited by realistic road roughness input is set up. The active control is exerted through a d.c. motor-driven air-pump. The model is used to show that essentially all the advantages of active control, within the terms of reference, are obtained by employing the control only at low frequencies and having the suspension parameters adapt to the running conditions as they vary. Control laws are derived using limited state feedback, linear stochastic optimal control theory and power consumption, and space requirements are evaluated. System performance is shown to be good in comparison with other known arrangements and encouragement for further work to extend the results is given.

Parametric Study on Proportional Integral Derivative Controlled Semi-Active Suspension System

2016 ◽  
Vol 8 (1) ◽  
Author(s):  
E.M Allam ◽  
M.A.A Emam ◽  
Eid.S Mohamed
Keyword(s):  
Active Suspension ◽  
Suspension System ◽  
Proportional Integral Derivative ◽  
Active System ◽  
Proportional Integral ◽  
Quarter Car Model ◽  
Suspension Systems ◽  
Working Space ◽  
Active Suspension Systems ◽  
Quarter Car

This paper presents the effect of the suspension working space, body displacement, body acceleration and wheel displacement for the non-controlled suspension system (passive system) and the controlled suspension system of a quarter car model (semi-active system), and comparison between them. The quarter car passive and semi-active suspension systems are modelled using Simulink. Proportional Integral Derivative controllers are incorporated in the design scheme of semi-active models. In the experimental work, the influence of switchable damper in a suspension system is compared with the passive and semi-active suspension systems.

Optimal Design of Active and Semi-Active Suspensions Including Time Delays and Preview

1993 ◽  
Vol 115 (4) ◽  
pp. 498-508 ◽  
Author(s):  
A. Hac´ ◽  
I. Youn
Keyword(s):  
Ride Comfort ◽  
Controller Design ◽  
Piecewise Linear ◽  
Active Suspension ◽  
Front Wheel ◽  
Active System ◽  
Control Laws ◽  
The Road ◽  
Suspension Systems ◽  
And Control

Several control laws for active and semi-active suspension based on a linear half car model are derived and investigated. The strategies proposed take full advantage of the fact that the road input to the rear wheels is a delayed version of that to the front wheels, which in turn can be obtained either from the measurements of the front wheels and body motions or by direct preview of road irregularities if preview sensors are available. The suspension systems are optimized with respect to ride comfort, road holding and suspension rattle space as expressed by the mean-square-values of body acceleration (including effects of heave and pitch), tire deflections and front and rear suspension travels. The optimal control laws that minimize the given performance index and include passivity constraints in the semi-active case are derived using calculus of variation. The optimal semi-active suspension becomes piecewise linear, varying between passive and fully active system and combinations of them. The performances of active and semi-active systems with and without preview were evaluated by numerical simulation in the time and frequency domains. The results show that incorporation of time delay between the front and rear axles in controller design improves the dynamic behavior of the rear axle and control of body pitch motion, while additional preview improves front wheel dynamics and body heave.

Simulation and Analysis of a Fractionally Controlled Active Suspension System Using Quarter Car Model

2015 ◽  
Author(s):  
Duval A. Johnson
Keyword(s):  
Fractional Calculus ◽  
Body Position ◽  
Active Suspension ◽  
Suspension System ◽  
Control Force ◽  
Active System ◽  
Suspension Systems ◽  
Car Suspension ◽  
Automobile Suspension ◽  
Quarter Car

This study is conducted to provide preliminary data that fractional calculus can be used to optimize active automobile suspension systems. Most automobile suspension systems perform their duties using a single spring with fixed damping rates and are referred to as being a passive system. An active suspension system has the ability to directly control force actuators in the suspension system or by varying the damping rates within the shock absorbers to provide control over body position, velocity, and acceleration. A mathematical model for a quarter car suspension system has been obtained to compare passive, integer, and fractionally controlled active suspension systems and show that fractional calculus may be used to improve the performance of any active system.

Intelligent PD controller design for active suspension system based on robust model-free control strategy

2019 ◽  
Vol 233 (14) ◽  
pp. 4863-4880 ◽  
Author(s):  
Maroua Haddar ◽  
Riadh Chaari ◽  
S Caglar Baslamisli ◽  
Fakher Chaari ◽  
Mohamed Haddar
Keyword(s):  
Controller Design ◽  
Design Method ◽  
Active Suspension ◽  
Vehicle Speed ◽  
Pd Controller ◽  
Suspension Systems ◽  
Model Free ◽  
Robust Model ◽  
Road Disturbance ◽  
Model Free Control

A novel active suspension control design method is proposed for attenuating vibrations caused by road disturbance inputs in vehicle suspension systems. For the control algorithm, we propose an intelligent PD controller structure that effectively rejects online estimated disturbances. The main theoretical techniques used in this paper consist of an ultra-local model which replaces the mathematical model of quarter car system and a new algebraic estimator of unknown information. The measurement of only input and output variables of the plant is required for achieving the reference tracking task and the cancellation of unmodeled exogenous and endogenous perturbations such as roughness road variation, unpredictable variation of vehicle speed and load variation. The performance and robustness of the proposed active suspension algorithm are compared with ADRC control and LQR control. Numerical results are provided for showing the improvement of passenger comfort criteria with model-free control.

The Impact of Electric Hybrid Compressor to Make Transport Environmentally Friendly

2013 ◽  
Vol 391 ◽  
pp. 207-212
Author(s):  
Maciej Bajerlein
Keyword(s):  
Energy Consumption ◽  
Operating Conditions ◽  
Vehicle Speed ◽  
Suspension Systems ◽  
Actual Operating ◽  
Vehicle Operation ◽  
Total Energy Balance ◽  
The Impact ◽  
Road Emission ◽  
Speed Engine

This paper presents the investigations, whose aim was to determine the influence of the operation of electric and mechanical compressors on the energy consumption of city buses in public transport. The tests were performed on pneumatic systems used in city transit vehicles whose underlying component is a compressor generating pressure for the brake and suspension systems. Owing to the application of a portable analyzer - SEMTECH DS the emissions (with a secondly resolution) of CO, HC, NOx, CO2 in the exhaust gases were measured. The on-road emission tests were performed in the actual operating conditions in SORT driving tests. These tests reflect the actual vehicle operation in a real task through preset procedures of their realization and measurements determining the energy consumption and exhaust emissions or the influence of the vehicle accessories and all variables (vehicle speed, engine load, acceleration or distance covered) on the total energy balance. The on-road tests were performed on a runway of the Bednary airstrip in Poland.

Zero-Energy Active Suspension System for Automobiles With Adaptive Sky-Hook Damping

2013 ◽  
Vol 135 (1) ◽  
Author(s):  
Kalpesh Singal ◽  
Rajesh Rajamani
Keyword(s):  
Active Suspension ◽  
Suspension System ◽  
Energy Management System ◽  
Zero Energy ◽  
Passive System ◽  
Active System ◽  
Active Suspensions ◽  
Resonant Frequencies ◽  
Active Systems ◽  
Automotive Suspension

Previous research has shown that a semiactive automotive suspension system can provide significant benefits compared to a passive suspension but cannot quite match the performance of a fully active system. The advantage of the semiactive system over an active system is that it consumes almost zero energy by utilizing a variable damper whose damping coefficient is changed in real time, while a fully active suspension consumes significant power for its operation. This paper explores a new zero-energy active suspension system that combines the advantages of semiactive and active suspensions by providing the performance of the active system at zero energy cost. Unlike a semiactive system in which the energy is always dissipated, the proposed system harvests and recycles energy to achieve active operation. An electrical motor-generator is used as the zero-energy actuator and a controller and energy management system are developed. An energy adaptive sky-hook gain is proposed to prevent the system from running out of energy, thereby eliminating the need to switch between passive and active systems. The results show that the system performs at least as well as a passive system for all frequencies, and is equivalent to an active system for a broad range of frequencies including both resonant frequencies.

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