A Methodology to Integrate a Nonlinear Shock Absorber Dynamics into a Vehicle Model for System Identification

2011 ◽  
Vol 4 (1) ◽  
pp. 527-534 ◽  
Author(s):  
Yan Cui ◽  
Thomas Kurfess ◽  
Michael Messman
Keyword(s):  
System Identification ◽  
Shock Absorber ◽  
Vehicle Model ◽  
Nonlinear Shock

Vehicle Parameter Identification for Vertical Dynamics

2014 ◽  
Vol 137 (2) ◽  
Author(s):  
Yan Cui ◽  
Thomas R. Kurfess
Keyword(s):  
Experimental Data ◽  
System Identification ◽  
Parameter Identification ◽  
Shock Absorber ◽  
Vehicle Model ◽  
Identification Methods ◽  
Car Model ◽  
Nonlinear Hysteresis ◽  
Hysteretic Characteristics ◽  
Identification Techniques

In this paper, a nonlinear full car model considering the nonlinear and hysteretic characteristics of the shock absorber is developed. An approach to integrate the hybrid shock absorber model into the vehicle model using system identification techniques is then presented. To validate the approach, parameter identification of the nominal linear full car model and parameter identification of the full car model with nonlinear/hysteresis shock absorber force input are compared. The target vehicle is tested on an MTS Systems Corporation tire-coupled 4-post road simulator and the experimental data validate the system identification methods proposed in this paper.

Construction principle of NES shock absorber and its application in frame structure

2019 ◽  
Vol 16 (4) ◽  
pp. 625-645
Author(s):  
Haixu Yang ◽  
Feng Zhu ◽  
Haibiao Wang ◽  
Liang Yu ◽  
Ming Shi
Keyword(s):  
Finite Element ◽  
Seismic Response ◽  
Seismic Performance ◽  
Shock Absorber ◽  
Frame Structure ◽  
Shock Absorption ◽  
Absorption Effect ◽  
Content Type ◽  
Main Structure ◽  
Nonlinear Shock

Purpose The purpose of this paper is to describe the structure of nonlinear dampers and the dynamic equations, and nonlinear realization principles and optimize the parameters of nonlinear dampers. Using the finite element method to analyze the seismic performance of the frame structure with shock absorber. Design/methodology/approach The nonlinear shock absorber was installed in a six-storey reinforced concrete frame structure to study its seismic performance. The main structure was designed according to the eight degree seismic fortification intensity, and the time history dynamic analysis was carried out by Abaqus finite element software. EL-Centro, Taft and Wenchuan seismic record were selected to analyze the seismic response of the structure under different magnitudes and different acceleration peaks. Findings Through the principle study and parameter analysis of the nonlinear shock absorber, combined with the finite element simulation results, the shock absorption performance and shock absorption effect of the nonlinear energy sink (NES) nonlinear shock absorber are given as follows: first, the damping of the NES shock absorber is satisfied, and the linear spring stiffness and nonlinear stiffness of the shock absorber are based on the relationship k1=kn×kl2, so that the spring design length is fixed, and the linear stiffness of the shock absorber can be obtained. The nonlinear shock absorber has the characteristics of high rigidity and frequency bandwidth, so that the frequency is infinitely close to the frequency of the main structure, and when the mass of the shock absorber satisfies between 0.056 and 1, a good shock absorption effect can be obtained, and the reinforced concrete with the shock absorber is obtained. The frame structure can effectively reduce the seismic response, increase the natural vibration period of the structure and reduce the damage loss of the structure. Second, the spacer and each additional shock absorber have a small difference in shock absorption effect. After the shock absorber parameters are accurately calculated, the number of installations does not affect the shock absorption effect of the structure. Therefore, the shock absorber is properly constructed and accurately calculated. Parameters can reduce costs. Originality/value New shock absorbers reduce earthquake-induced damage to buildings.

Simulation Research for Self-Energizing Leveling Systems

2011 ◽  
Vol 211-212 ◽  
pp. 494-499
Author(s):  
Xiao Bin Ning ◽  
Cui Ling Zhao ◽  
Ji Sheng Shen
Keyword(s):  
Simulation Model ◽  
Shock Absorber ◽  
Simulation Method ◽  
Vehicle Model ◽  
Ride Height ◽  
Simulation Research ◽  
Vehicle Simulation ◽  
The Road ◽  
Full Vehicle ◽  
Internal Configuration

In order to decay vibration and recycle energy, the shock absorber that is self-energizing leveling systems was researched. The co-simulation method was adopted. A mathematical model for the shock absorber was built using the software MSC.EASY5, and the establishment of this model was based on the analysis of internal configuration and characteristics of valves. Debugging simulation of this model was also conducted. Vehicle simulation model was built using MSC.ADAMS. The assembly between vehicle simulation model and the shock absorber was realized through co-simulation between ADAMS/CAR and MSC.EASY5. After the integration of the full vehicle model the road test simulation with the input of random road surface signal was conducted. The simulation results shows that self-energizing leveling systems can partly recycle this energy which can be used to adjust ride height due to load change of automobile. This shock absorber is improving the ride performance of vehicle.

Reducing Vertical and Angular Accelerations With Nonlinear Asymmetrical Shock Absorber in Passenger Vehicles

2013 ◽  
Author(s):  
Marcos Silveira ◽  
Bento R. Pontes ◽  
José M. Balthazar
Keyword(s):  
Shock Absorber ◽  
Ride Comfort ◽  
Nonlinear Characteristics ◽  
Passenger Vehicles ◽  
Car Model ◽  
Shock Absorbers ◽  
Nonlinear Shock ◽  
Angular Oscillations ◽  
Impact Absorption ◽  
Severity Parameter

The behaviour of linear and nonlinear shock absorbers are compared to diminish vertical and angular (pitch) accelerations of passenger vehicles, improving comfort by result. A 4-dof half-car model is used with three configurations of dampers: symmetrical, asymmetrical and front asymmetrical. The analyses use three standard road inputs and include variation of the severity parameter, the asymmetry ratio and the velocity of the vehicle. The comparison shows that the asymmetrical system, with nonlinear characteristics, tends to have a smoother and more progressive behaviour. The results show that the use of the front asymmetrical system diminishes angular oscillations of the vehicle. As lower levels of acceleration are essential for improved ride comfort, the use of asymmetrical systems for vibrations and impact absorption is a superior choice for passenger vehicles.

Dynamic Analysis of Self-Energizing Shock Absorber of Suspension for Energy-Regenerative

2011 ◽  
Vol 80-81 ◽  
pp. 746-751
Author(s):  
Ji Sheng Shen ◽  
Xiang Man Ye ◽  
Xiao Bin Ning
Keyword(s):  
Dynamic Analysis ◽  
Simulation Model ◽  
Shock Absorber ◽  
Vehicle Model ◽  
Ride Height ◽  
Vehicle Simulation ◽  
System A ◽  
Nonlinear Vehicle Model ◽  
Multi Body ◽  
Internal Configuration

Design of self-energizing shock absorber of suspension of SVU, a multi degree of freedom mechanism, is a challenge. In order to decay vibration and recycle energy, self-energizing shock absorber was researched. This paper primarily focuses on kinematics and dynamic analysis in multi-body system (MBS) and validation of system. A simulation model for self-energizing shock absorber was built using the software MATLAB, and the establishment of this model was based on the analysis of internal configuration and characteristics of valves. Vehicle simulation model was built using MBS. The assembly between vehicle simulation model and the shock absorber was realized through co-simulation between MBS and MATLAB. The optimal design of suspension is investigated, in order to improve vertical ride and road-friendliness of vehicles, while maintaining enhanced roll stability. A nonlinear vehicle model is developed to study vertical as well as roll dynamics of vehicles. The simulation results shows that suspension with self-energizing shock absorber can partly energy-regenerative which can be used to adjust ride height due to load change of automobile. Self-energizing shock absorber is also improving the ride performance of vehicle.

Realization and Comparison of System Identification Based on Different Least Squares Methods

2012 ◽  
Vol 226-228 ◽  
pp. 2167-2170
Author(s):  
Xu Dong Zhang ◽  
Ji Fu Guan ◽  
Liang Gu
Keyword(s):  
System Identification ◽  
Transfer Function ◽  
Parameter Identification ◽  
Least Squares ◽  
Recursive Least Squares ◽  
System Model ◽  
Vibration System ◽  
Vehicle Model ◽  
Identification Theory ◽  
Discrete Transfer Function

System identification, which includes parameter identification and non-parameter identification, is to estimate its mathematical model based on the input and output observation in system. This paper discusses the system identification theory and establishes a transfer function of 1/4 vehicle’s second-order vibration system model. Through the discrete transfer function, the system’s difference equation can be obtained to identify the system in two ways, RLS (recursive least squares) and RELS (extended recursive least squares). Finally, the paper makes a comparative analysis about RLS and RELS in connection with the vehicle model. The results show that RELS method is more accurate and has stronger convergence than RLS method, which provides the basis for the researching of control system’s algorithm, simulation and making control strategy.

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