Optimal Active Control of Vehicle Suspension System Including Time Delay and Preview for Rough Roads

2002 ◽  
Vol 8 (7) ◽  
pp. 967-991 ◽  
Author(s):  
Javad Marzbanrad ◽  
Goodarz Ahmadi ◽  
Yousef Hojjat ◽  
Hassan Zohoor

An optimal preview control of a vehicle suspension system traveling on a rough road is studied. A three-dimensional seven degree-of-freedom car-riding model and several descriptions of the road surface roughness heights, including haversine (hole/bump) and stochastic filtered white noise models, are used in the analysis. It is assumed that contact-less sensors affixed to the vehicle front bumper measure the road surface height at some distances in the front of the car. The suspension systems are optimized with respect to ride comfort and road holding preferences including accelerations of the sprung mass, tire deflection, suspension rattle space and control force. The performance and power demand of active, active and delay, active and preview systems are evaluated and are compared with those for the passive system. The results show that the optimal preview control improves all aspects of the vehicle suspension performance while requiring less power. Effects of variation of preview time and variations in the road condition are also examined.

1995 ◽  
Vol 7 (4) ◽  
pp. 307-311
Author(s):  
Hideo Tobata ◽  
◽  
Takeshi Kimura ◽  
Yohsuke Akatsu

It is known that the ride comfort of a vehicle equipped with active suspension can be further improved if a priori information about the road surface, i.e., preview control, is used. This paper discusses the application of preview control to the rear wheels of a vehicle with active suspension. Information about the front wheels' vertical motion is used to estimate the vertical travel of the rear wheels. Vibration transmitted from the road surface to the vehicle body through the rear suspension can be estimated from the vertical motion of the wheels. Thus, the control force that should be generated by the rear suspension actuators can be obtained. Simulation results reveal that preview control provides an accurate estimate of road force inputs, enabling the vertical acceleration of the vehicle body to be reduced for further improvement in ride comfort. The results of vehicle driving tests also confirm that the preview-control force serves to reduce the vertical acceleration of the vehicle body. Cooperation between preview control and a skyhook damper is also discussed and shown to be effective in reducing vehicle body vibration.


2018 ◽  
Vol 10 (7) ◽  
pp. 168781401877386 ◽  
Author(s):  
Hongbo Wang

Vehicle suspension system is the key part in vehicle chassis, which has influence on the vehicle ride comfort, handling stability, and security. The extension control, which is not constrained by common control method, could further improve the suspension system performance. The 7 degree-of-freedom suspension model is built. The extension controller is designed according to the function differences. In different extension set domains according to the correlation function, the corresponding control strategy is designed to ensure the suspension system obtains optimal performance in the classical domain and expands the controllable range outside the classical domain as large as possible. By adopting game theory, the domain is optimally divided, and the domain boundary control jump is smoothed by introducing Takagi–Sugeno–Kang fuzzy control into the extension control. Through the simulation and results comparison, it is demonstrated that the extension control could further improve the vehicle ride comfort than the optimal control and the extension control ability can be further promoted through domain game and Takagi–Sugeno–Kang fuzzy control. The analysis of the influence of the extension controller parameter varieties on suspension system performance shows that the error-weighted coefficient and control coefficient have significant effect to the suspension system performance.


Author(s):  
A.S. Emam ◽  
H. Metered ◽  
A.M. Abdel Ghany

In this paper, an optimal Fractional Order Proportional Integral Derivative (FOPID) controller is applied in vehicle active suspension system to improve the ride comfort and vehicle stability without consideration of the actuator. The optimal values of the five gains of FOPID controller to minimize the objective function are tuned using a Multi-Objective Genetic Algorithm (MOGA). A half vehicle suspension system is modelled mathematically as 6 degrees-of-freedom mechanical system and then simulated using Matlab/Simulink software. The performance of the active suspension with FOPID controller is compared with passive suspension system under bump road excitation to show the efficiency of the proposed controller. The simulation results show that the active suspension system using the FOPID controller can offer a significant enhancement of ride comfort and vehicle stability.


2017 ◽  
Vol 2017 ◽  
pp. 1-13 ◽  
Author(s):  
Hui Pang ◽  
Ying Chen ◽  
JiaNan Chen ◽  
Xue Liu

As the road conditions are completely unknown in the design of a suspension controller, an improved linear quadratic and Gaussian distributed (LQG) controller is proposed for active suspension system without considering road input signals. The main purpose is to optimize the vehicle body acceleration, pitching angular acceleration, displacement of suspension system, and tire dynamic deflection comprehensively. Meanwhile, it will extend the applicability of the LQG controller. Firstly, the half-vehicle and road input mathematical models of an active suspension system are established, with the weight coefficients of each evaluating indicator optimized by using genetic algorithm (GA). Then, a simulation model is built in Matlab/Simulink environment. Finally, a comparison of simulation is conducted to illustrate that the proposed LQG controller can obtain the better comprehensive performance of vehicle suspension system and improve riding comfort and handling safety compared to the conventional one.


Author(s):  
Warren S. Hurter ◽  
Nickey Janse Van Rensburg ◽  
Daniel M. Madyira ◽  
Gert Adriaan Oosthuizen

To create an energy efficient vehicle there are a number of aspects that need to be optimized, namely; the drive train of the vehicle and energy source, aerodynamics and weight. Focusing on weight reduction, while still maintaining the desired performance and structural strength, many manufacturers are turning to advanced composites due to their superior strength to weight characteristics. Solar car racing provides a research platform that drives this innovation through technology development and efficiency. A lightweight vehicle suspension system design is being presented, together with an introduction into future testing. A suspension system is made up of a number of critical components which are dynamically loaded during standard operation due to undulating forces imposed by the road surface. Unidirectional cross-wound carbon fiber tubing is used for suspension and steering arms. The tubing is interfaced with small steel inserts and pivoting arm tie rod ends. Concerns within the design are the adhesive bonding of the carbon tubing to the steel inserts, and what type of tensile loading the interface can withstand. Due to forces imposed on the system during cornering and shock loading the components are required to withstand a minimum of 1.2 times the weight of the overall vehicle, i.e. 258 kg. Tensile test results show that the mechanical properties of the adhesive joints rely somewhat on the surface characteristics and bond preparation. The target load of 258 kg was successfully obtained under static loading for two types of sample sets. The first based on the standard for describing the lap shear strength of adhesively bonded carbon fiber to aluminum, and the second based on the working component itself.


1992 ◽  
Author(s):  
Sueharu Nagiri ◽  
Shun'ichi Doi ◽  
Shoh-ichi Shoh-no ◽  
Nobuo Hiraiwa

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