A New Vehicle Suspension Semi-Active Control Method for Enhancing Ride Properties

2014 ◽  
Vol 968 ◽  
pp. 259-262
Author(s):  
Li Qiang Jin ◽  
Yue Liu ◽  
Jian Hua Li ◽  
Gang He
Keyword(s):  
Active Control ◽  
Control Method ◽  
Hybrid Control ◽  
Random Excitation ◽  
The Body ◽  
Body Acceleration ◽  
The Road ◽  
Vehicle Suspensions ◽  
Quarter Car Model ◽  
Power Spectral

In this paper, a new control theory will be proposed for the purpose of enhancing vehicle ride performance. In the first step, a quarter car model with two DOF will be analyzed after which the classical semi-active control idea and a new control method will be built. Then a new hybrid control model based on body acceleration and classical one will be provided, after which the advantage of this controller will be studied. All the models that proposed will be accomplished through matlab/simulink. The outcome parameters of two types, namely, the body acceleration and the suspension deflection will be compared in frequency domain among three conditions which can be described as passive, classical semi-active control and hybrid control respectively. Then random excitation will be given as the road input to get power spectral density curves for further compare. Though the curves we can easily come into a conclusion that vehicle suspensions armed with this new controller will show the best ride properties which hold practical values.

1⁄4 Car Model for Suspension Trim Corrector Performances Evaluation

2016 ◽  
Vol 823 ◽  
pp. 205-210
Author(s):  
Adrian Ioan Niculescu
Keyword(s):  
Contact Force ◽  
Harmonic Functions ◽  
Degrees Of Freedom ◽  
The Body ◽  
Vertical Acceleration ◽  
Vertical Movements ◽  
The Road ◽  
Quarter Car Model ◽  
Car Model ◽  
Quarter Car

The paper presents a complex quarter car model obtained with ADAMS software, View module, useful in the first stage of suspension dimensioning and optimization.The model is equipped with compression and rebound stopper buffer and suspension trim corrector.The proposed quarter car model with two degrees of freedom (wheel and body) performs all these goals allowing changing:Geometrical elementsPosition of equilibrium, depending on vehicle load;Trim correction;Elastic and dissipative characteristics of the suspension and tire;Suspension stroke;Road profile, assessed either by simple or summation of harmonic functions or reproducing real roadsBuffers (for stroke limitation) position and characteristics;The models developed provide information on:Vertical stability assessed by vertical movements of the body and the longitudinal and transversal stability evaluated based on adherence characterized by wheel ground contact force and frequency of soil detachment wheel.Comfort assessed on the basis of body vertical acceleration and collision forces to the stroke ends.The body-road clearanceThe trim corrector efficiencyAll above performances evaluated function the road unevenness, acceleration, deceleration, turning regime.The damping characteristic is defined by damping forces at different speed for each strokes respectively one for rebound and other for compression.The contact force road-wheel is defined based tire rigidity law.The stopper buffer forces on rebound and compression are defined based each specific rigidity characteristics.The road excitation is realized with a function generator.The software allow the model evolution visualisation in real time, also generating the diagrams of displacements, forces, accelerations, speeds, for each elements or for relative evolution between diverse elements.The simulation was realized for unloaded and fully loaded car using a road generated by a sum of harmonic functions presented in equation (8).The excitation covers the specific frequencies area, being under the body frequencies up to the wheel proper frequencies.The realized ¼ car model, have reached the goal to evaluate the suspension trim correction advantages.The simulations confirm the trim corrector increases the suspension performances, thus for the analyzed case the trim corrector increase simultaneous:Body-ground clearance (evaluated by body higher increasing) between 18.5÷55.1 %Body stability (evaluated by maximal body displacement) between 9.8÷11.4 %Body comfort (evaluated by maximal body acceleration) between 3.4÷35.5 %Adherence (evaluated by maximal and RMS wheel-groundcontact force variation) between 7.0÷12.1 %Body and axles protection (evaluated by buffer strike force) between 10.8÷38.2 %

scholarly journals Simulation of Pavement Random Excitation Based on Harmonic Superposition Method

2021 ◽  
Vol 2 (3) ◽  
Author(s):  
Kehui Ma ◽  
Yongguo Zhang ◽  
Xü Zhen
Keyword(s):  
Spectral Density ◽  
Power Spectral Density ◽  
Ride Comfort ◽  
Random Excitation ◽  
Superposition Method ◽  
Generation Model ◽  
The Road ◽  
Power Spectral ◽  
Control Research ◽  
The Relationship

The road input model is very important in the analysis of vehicle ride comfort and handling stability. Based on the analysis of the relationship between the spatial frequency power spectral density and the time power spectral density of the road, the road signal generation model is established. The simulation is carried out under different vehicle speeds, and the B and C-level random road time excitation signals are generated. The power spectral density is used to compare the simulation results of the model with the road classification standard. The experimental results show that the results are accurate and can provide reliable excitation signals for vehicle control research.

scholarly journals On the Benefits of Semi-Active Suspensions with Inerters

2012 ◽  
Vol 19 (3) ◽  
pp. 257-272 ◽  
Author(s):  
Xin-Jie Zhang ◽  
Mehdi Ahmadian ◽  
Kong-Hui Guo
Keyword(s):  
High Performance ◽  
Control Method ◽  
Hybrid Control ◽  
Active Suspension ◽  
Vertical Acceleration ◽  
Active Suspensions ◽  
Quarter Car Model ◽  
Suspension Systems ◽  
Car Model ◽  
Quarter Car

Inerters have become a hot topic in recent years especially in vehicle, train, building suspension systems, etc. Eight different layouts of suspensions were analyzed with a quarter-car model in this paper. Dimensionless root mean square (RMS) responses of the sprung mass vertical acceleration, the suspension travel, and the tire deflection are derived which were used to evaluate the performance of the quarter-car model. The behaviour of semi-active suspensions with inerters using Groundhook, Skyhook, and Hybrid control has been evaluated and compared to the performance of passive suspensions with inerters. Sensitivity analysis was applied to the development of a high performance semi-active suspension with an inerter. Numerical simulations indicate that a semi-active suspension with an inerter has much better performance than the passive suspension with an inerter, especially with the Hybrid control method, which has the best compromise between comfort and road holding quality.

Cargo Ride Safety Analysis of Trucks for Four Excitation Cases

2010 ◽  
Vol 118-120 ◽  
pp. 660-664
Author(s):  
Li Qun Guo ◽  
Deng Feng Wang
Keyword(s):  
Element Model ◽  
The Body ◽  
Three Dimension ◽  
Commercial Vehicles ◽  
3D Finite Element ◽  
The Road ◽  
Full Vehicle ◽  
Power Spectral ◽  
Computation Algorithm ◽  
Vertical Accelerations

Excessive levels of vibration in commercial vehicles, due to excitation from the road irregularities, can lead to cargo damage and safety problems. In order to study the cargo ride safety problem, a three dimension (3D) finite element model of full vehicle was established, which differs from the previous two dimension (2D) one. The computation algorithm for acceleration power spectral density (PSD) and root mean square (RMS) was also given. For the sake of comparisons, two frames with different stiffness were given in the computations of PSD and RMS of body vertical accelerations for four excitation cases. The computed results showed that when the stiffness of the frame increases, the RMS values of the body decreases strongly at the frequency band 14-26Hz, which can effectively improve the cargo ride safety.

The Optimal Control Method of Impulse Response in Prosthetic Leg

2014 ◽  
Vol 915-916 ◽  
pp. 1181-1185
Author(s):  
Xin Yi Xiao ◽  
Han Bin Xiao
Keyword(s):  
Optimal Control ◽  
Active Control ◽  
Impulse Response ◽  
Passive Control ◽  
Control Method ◽  
Control Variable ◽  
The Body ◽  
Control Techniques ◽  
Suspension Systems ◽  
Optimal Control Method

Passive control and semi-active control of vibration in mechanical systems have recently successfully been used in automobiles and airplanes suspension systems. These control techniques are able to guarantee the performances of all vibration structures. Unfortunately, the knowledge and data has not been readily applied to human prosthetics. The information collected can be directly applied to accelerate research into dampening for prosthetics. A focus of this paper is on modeling and controlling vibrations by a given impulse onto prosthetic legs. Simulations of using passive control and idealized skyhook dampening are using Matlab to complete. Through model analysis, control variable, simulation procedures and comparison of two modeling, the models have been refined and with idealized skyhook dampening suspension provide significant improvement of the body characteristics compared with passive suspensions.

Design and comparisons of adaptive harmonic control for a quarter-car active suspension

2021 ◽  
pp. 095440702110192
Author(s):  
Teodor-Constantin Nichiţelea ◽  
Maria-Geanina Unguritu
Keyword(s):  
Active Suspension ◽  
The Body ◽  
Control Algorithms ◽  
Multiple Control ◽  
Control Solution ◽  
Body Acceleration ◽  
Front Suspension ◽  
The Road ◽  
Harmonic Control ◽  
Quarter Car

Car suspensions have the job to keep the tires in contact with the road surface as much as possible, to deliver steering stability with good handling and to guarantee passenger comfort. Most modern vehicles have independent front suspension and many vehicles also have independent rear suspension. Independent suspensions are preferred instead of dependent suspensions for their better ride handling, stability, steering and comfort but they provide less overall strength and a complex design which increases the cost and maintenance expenses for such a suspension. For this reason, automotive engineers struggle to discover new suspension components or advanced control solutions. Taking a step forward in this direction, the paper presents in the beginning one of the well-known mathematical models of a quarter-car active suspension. The obtained model is then implemented in a MATLAB/Simulink simulation which compares multiple control solutions. The only feedback considered for each control algorithm is the measurement of the body acceleration. Among these investigated control algorithms is the adaptive harmonic control solution proposed by this paper. The controller generates a harmonic control signal with variable amplitude and frequency based on the body acceleration feedback. The comparison analysis shows that the proposed control solution demonstrates quite good potential, generating in some cases better results than the other control algorithms.

Ride comfort control of in-wheel motor drive unmanned ground vehicles with energy regeneration

2020 ◽  
pp. 095440702093336
Author(s):  
Lipeng Zhang ◽  
Chenhui Ren ◽  
Xinmao Yuan ◽  
Wei Zhang
Keyword(s):  
Ride Comfort ◽  
Control Method ◽  
The Body ◽  
Vibration Energy ◽  
Motor Drive ◽  
Optimal Control Strategy ◽  
Body Acceleration ◽  
Control Functions ◽  
Save Energy ◽  
Passive Suspensions

Adopting in-wheel motor drive can improve vehicle dynamics control functions, which is the most ideal drive mode of unmanned ground vehicle. However, with the increase of the heavy unspring-mass vibration energy while the vehicle running on uneven road, the ride comfort will be seriously deteriorated. To solve the problem and save energy, the ride comfort control based on regenerative suspensions is adopted. By analyzing the vibration performance, the adverse effects of the vehicle equipped in-wheel motors with passive suspensions are revealed. Then, the dynamics model of the regenerative suspension is built. Based on the suspension power recovery, the multi-state optimal control strategy for improving the ride comfort is designed. Finally, comparing the simulation results of regenerative suspensions with the test results of passive suspensions, when the vehicle mass ratio decreases from 8:1 to 4:1, the body acceleration and the root mean square value of tire dynamic load increase by 28.1% and 31.6%, correspondingly. With the control method, the body acceleration is decreased by 23% and reaches the level of conventional vehicles. Furthermore, part of the vehicle vibration energy can be recovered and the vehicle driving range can be extended.

scholarly journals Single Tyre System Design and Implementation using Optimization based PI Controller

2019 ◽  
Vol 8 (2S5) ◽  
pp. 90-92
Keyword(s):  
Genetic Algorithm ◽  
Particle Swarm Optimization ◽  
System Design ◽  
Pi Controller ◽  
The Body ◽  
Swarm Optimization ◽  
Body Acceleration ◽  
Proportional Integral ◽  
The Road ◽  
Design And Implementation

This work described in the paper to show the implementation of Proportional Integral (PI) controller, Genetic algorithm based PI (GAPI), and Particle swarm optimization based PI (PSO-PI) for a Quarter Car System. The trip comfort is developed by means of the decrease of the body acceleration caused by the car body, due to the smoothness of the road. This paper tells about the model and controllers used in the study and discuss the vehicle response results. In the conclusion, a comparison of PI, GA-PI, and PSO-PI is shown using MATLAB simulations.

Progressive Rate Steel Vehicle Suspension

2006 ◽  
Author(s):  
Wieslaw J. Oledzki
Keyword(s):  
Thermodynamic Properties ◽  
Present Article ◽  
The Body ◽  
Vehicle Suspension ◽  
Adiabatic Exponent ◽  
The Road ◽  
Vehicle Suspensions ◽  
The Past ◽  
Linear Characteristic ◽  
Desirable Feature

It is well known that progressiveness of the damping characteristic of vehicle suspension is a highly desirable feature that substantially improves shock absorption transmitted from the road wheels to the body of a vehicle. It is also well known that progressive rate vehicle suspensions with smooth (i.e. differentiable) damping characteristic commonly in use are pneumatic and hydro-pneumatic ones. However, these suspensions are inferior to steel ones in many aspects such as strength, durability, reliability and cost, and their damping characteristic, being determined by the thermodynamic properties (adiabatic exponent) of the gas (air or nitrogen) they utilize, cannot be freely adjusted and is far from optimum. There are also some progressive rate vehicle suspensions fitted with steel springs, but they usually features inferior non-differentiable damping characteristic. The problem of constructing purely mechanical steel progressive rate vehicle suspension has been undertaken by many inventors, but none of such suspensions proposed in the past was a success. This is due to the fact that those suspensions used unreliable and perishable cam mechanisms to achieve required non-linearity of damping characteristic. In the present article we briefly discuss an innovative recently patented [1-4] vehicle suspension, that produces progressive rate smooth damping characteristic out of linear characteristic of steel spring of any kind, which damping characteristic can be adjusted to any specific requirements, and which features extraordinarily compact and robust structure. It is to be stressed that the suspension presented in this paper has yet not been tested in a vehicle, but some measurements has been made using a steel model of a "flat" version of the suspension mechanism proving general assumptions behind the design.

A Pointwise Approach for Synthesizing Semi-Active Vehicle Suspensions

1995 ◽  
Author(s):  
Pei-Ming Chang ◽  
Suhada Jayasuriya
Keyword(s):  
Ride Comfort ◽  
Hybrid Control ◽  
Control Law ◽  
Optimization Approach ◽  
Vehicle Suspensions ◽  
Quarter Car Model ◽  
Control Scheme ◽  
Feedback Structure ◽  
One Step ◽  
Hybrid Control Scheme

Abstract Presented in this paper is a pointwise optimization approach for synthesizing semi-active vehicle suspensions. In particular, the control algorithm is obtained by optimizing a performance index pointwise in time. The resulting control law has a state feedback structure suitable for real time implementation and is a hybrid control scheme combining a simple one-step ahead minimization and an optimal-aiming strategy specifically chosen for increased ride comfort while satisfying constraints on road traction and rattle space. Simulations with a quarter car model confirm the efficacy of the proposed approach.

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