scholarly journals LQG Control Strategy for Enhancing Ride and Safety Performance of Electric Vehicle Driven by In-Wheel Motors

2015 ◽  
Vol 9 (1) ◽  
pp. 293-301
Author(s):  
LiQiang Jin ◽  
Yue Liu ◽  
JianHua Li
Keyword(s):  
Frequency Domain ◽  
Time Domain ◽  
Control Strategy ◽  
Dynamic Load ◽  
Vibration Reduction ◽  
Safety Performance ◽  
Quarter Car Model ◽  
Car Model ◽  
Lqg Control ◽  
Drive Motor

In this paper, a method for reducing unspring mass as well as improving safety and ride properties of vehicles driven by in-wheel motors will be provided. To begin with, the advantages of vehicles armed with in-wheel motors will be described, after which some drawbacks of this idea will be studied. Then, to getting a better analysis, quarter car model will be studied in frequency domain. Gain of body acceleration and wheel dynamic load, which can be equal to ride property and safety performance respectively, will be compared. Finally, an idea that makes the drive motor suspend will be proposed for enhancing the two properties and then a LQG controller will be provided for further optimization. Through the comparison in time domain and frequency domain, one can come to a conclusion that vehicles driven by suspended motors not only simplified the structures but also can be used as an absorber for vibration reduction.

Plumpness Analysis of Indicator Diagram for Vehicle Damper

2013 ◽  
Vol 415 ◽  
pp. 582-585
Author(s):  
Xing Xu ◽  
Zhen Cui ◽  
Jin Chao Zhang
Keyword(s):  
Frequency Domain ◽  
Time Domain ◽  
Dynamic Load ◽  
Performance Indicators ◽  
Load Distribution ◽  
The Body ◽  
Quantitative Index ◽  
Indicator Diagram ◽  
Vehicle Demand ◽  
Mathematical Relationships

According to the indicator diagram of damper, the indicator diagram plumpness was proposed as a quantitative index, and its mathematical relationships with the sprung mass acceleration, suspension dynamic travel and tire dynamic load were built. Moreover, the influence of the total area on suspension characteristics was analyzed in time domain and frequency domain. The results show that, the increase of the indicator diagram plumpness can effectively restrain the variation of suspension dynamic travel and tire dynamic load, meanwhile, the body acceleration will be enlarged. Excessive indicator diagram plumpness also affects the dynamic tire load distribution in frequency domain, and it will decrease the driving security. Therefore, it should be reasonably selected from the performance indicators, which is based on the requirement of vehicle demand in the design process.

A Comfort Oriented Control Strategy for Semi-Active Suspensions Based on Half Car Model

2010 ◽  
Author(s):  
Cristiano Spelta ◽  
Diego Delvecchio ◽  
Sergio M. Savaresi
Keyword(s):  
Optimal Control ◽  
Control Strategy ◽  
Optimal Performance ◽  
Optimal Control Strategy ◽  
Active Suspensions ◽  
Quarter Car Model ◽  
Car Model ◽  
Control Goal ◽  
Quarter Car ◽  
Effective Description

This paper is devoted to the design of a novel semi-active comfort-oriented control strategy based on the “half-car” modeling of the vehicle. The half car model is an effective description of the vertical behaviors in a vehicle like a motorcycle, since it is able to represent both the heave and pitch dynamics. A recent control strategy (the “Mix-1-Sensor”) have been proven to be the quasi-optimal control strategy when the system is described with a quarter car model and the comfort objective is the control goal. This paper presents an analysis of the performances of the Mix-1-Sensor implemented in a half car: this strategy is able to guarantee a quasi optimal performance in terms of heave dynamics but it is not able to manage the pitch dynamics efficiently. A pitch-oriented extension of this strategy is proposed in order to guarantee a better filtering of the pitch dynamics.

Comparison of a New Passive and Active Technology for Vibration Reduction of a Vehicle under Uncertain Load

2015 ◽  
Vol 807 ◽  
pp. 57-66 ◽  
Author(s):  
Philipp Hedrich ◽  
Ferdinand J. Cloos ◽  
Jan Würtenberger ◽  
Peter F. Pelz
Keyword(s):  
Energy Flow ◽  
New Technologies ◽  
Vibration Reduction ◽  
Electrical Energy ◽  
Driving Safety ◽  
Air Spring ◽  
Function Structure ◽  
Quarter Car Model ◽  
Car Model ◽  
Active Variant

This paper presents two new technologies in order to optimize the operation of a con-ventional spring-damper-system. Therefore, the function structure such as the energy flow of a con-ventional system is investigated and optimized. The first resulting technology is the fluid dynamicabsorber (FDA) which is still a passive solution and improves the energy flow of the conventionalspring-damper-system with the help of an absorber with a hydraulic transmission. The second tech-nology is the active air spring damper (AASD) which is an active variant of a spring-damper-systemand optimizes the energy flow by using electrical energy. We use a quarter car model to examine theperformance of our technologies and compare them in the conflict diagram where driving comfort vs.driving safety is shown within the scope of uncertainty. The FDA improves the driving safety at almostthe same comfort. The driving comfort is improved by using the AASD. We also examine the systembehavior at uncertain loads. The results show that they are capable of controlling this uncertainty.

scholarly journals The vibrations induced by surface irregularities in road pavements – a Matlab® approach

2013 ◽  
Vol 6 (3) ◽  
pp. 267-275 ◽  
Author(s):  
M. Agostinacchio ◽  
D. Ciampa ◽  
S. Olita
Keyword(s):  
Dynamic Load ◽  
Variable Speed ◽  
The Road ◽  
Quarter Car Model ◽  
Car Model ◽  
Road Pavement ◽  
Vehicle Mass ◽  
Road Roughness ◽  
Surface Irregularities ◽  
Iso 8608

Abstract Purpose The paper tackles the theme of evaluating dynamic load increases that the vehicle transfers to the road pavement, due to the generation of vibration produced by surface irregularities. Method The study starts from the generation, according to the ISO 8608 Standard, of different road roughness profiles characterized by different damage levels. In particular, the first four classes provided by ISO 8608 were considered. Subsequently, the force exchanged between the pavement and three typologies of vehicles (car, bus and truck) has been assessed by implementing, in Matlab®, the QCM (Quarter Car Model) characterized by a quarter vehicle mass and variable speed from 20 to 100 km/h. The analysis allows determining the amount of dynamic overload that causes the vibrational stress. Results/Conclusions The paper shows how this dynamic overload may be predetermined as a function of the pavements surface degradation. This is a useful reference for the purposes of designing and maintaining road pavements.

Research on the Influence of the Road-Friendliness by Semi-Active Suspension

2011 ◽  
Vol 311-313 ◽  
pp. 1182-1185
Author(s):  
Jie Li ◽  
Ai Hua Zhu ◽  
Heng Zeng ◽  
Jun Peng Li
Keyword(s):  
Control Strategy ◽  
Dynamic Load ◽  
Hybrid Control ◽  
Dynamic Performance ◽  
Active Suspension ◽  
Vehicle Dynamic ◽  
Damping Force ◽  
Joint Simulation ◽  
The Road ◽  
Car Model

In order to improve the road-friendliness of vehicle, this paper studies vehicle dynamic performance through establishing car model in ADAMS, hybrid control strategy in SIMULINK and the use of joint simulation technology. By using dynamic load coefficient and the road-friendliness index of dynamic load stress factor evaluate the road-friendliness of the semi-active suspension system with hybrid control strategy. The research shows that the road-friendliness will be better when the damping force distribution coefficient for 0.2 ~ 0.6.

Optimal Semi-Active Suspension with Preview Based on a Quarter Car Model

1992 ◽  
Vol 114 (1) ◽  
pp. 84-92 ◽  
Author(s):  
A. Hac´ ◽  
I. Youn
Keyword(s):  
Frequency Domain ◽  
Piecewise Linear ◽  
A Priori ◽  
Bilinear System ◽  
Active Suspension ◽  
Problem Formulation ◽  
System Response ◽  
Quarter Car Model ◽  
Car Model ◽  
Quarter Car

This paper deals with the synthesis of an optimal yet practical finite preview controller for a semi-active dissipative suspension system based on a two-degree-of-freedom (2-DOF) vehicle model. The proposed controller utilizes knowledge about approaching road disturbances obtained from preview sensors to minimize the effect of these disturbances. A truly optimal control law, which minimizes a quadratic performance index under passivity constraints, is derived using a variational approach. The optimal closed loop system becomes piecewise linear varying between two passive systems and a fully active one. It is shown that the steady state system response to a periodic input is also periodic and its amplitude is proportional to the amplitude of the input. Therefore, frequency domain characteristics in a classical sense can be generated. The problem formulation and the analytical solution are given in a general form and hence they apply to any bilinear system with system disturbances that are a priori unknown but some preview information is possible. The results of this analysis are applied to a quarter car model with semi-active suspension whose frequency domain and time domain performances are evaluated and compared to those of fully active and passive models. The effect of preview time on the system performance is also examined.

Robust Control of Electrohydraulically Actuated Friction Damper

2000 ◽  
Author(s):  
Emanuele Guglielmino ◽  
Kevin A. Edge
Keyword(s):  
Sliding Mode ◽  
Vibration Reduction ◽  
Control Loop ◽  
Friction Damper ◽  
Inherent Limitation ◽  
Active Device ◽  
Quarter Car Model ◽  
Sliding Surfaces ◽  
Car Model ◽  
Car Suspension

Abstract This paper focusses on the Sliding Mode Control (SMC) of a servo-driven dry-friction damper employed in a force control loop for the purpose of vibration reduction. An application to a car suspension is investigated using a quarter car model. The friction damper is a semi-active device: it can only oppose to the motion but not assist it. This inherent limitation requires particular attention in the design of the sliding surfaces. The performance of various types of sliding surface are compared, by means of computer simulation.

scholarly journals Adaptive Semiactive Cable Vibration Control: A Frequency Domain Perspective

2017 ◽  
Vol 2017 ◽  
pp. 1-12
Author(s):  
Z. H. Chen ◽  
Y. Q. Ni
Keyword(s):  
Frequency Domain ◽  
Time Domain ◽  
Semiactive Control ◽  
Control Performance ◽  
Linear Quadratic ◽  
Cable Vibration ◽  
Hilbert Huang Transform ◽  
Lqg Control ◽  
Force Tracking ◽  
Mr Damping

An adaptive solution to semiactive control of cable vibration is formulated by extending the linear quadratic Gaussian (LQG) control from time domain to frequency domain. Frequency shaping is introduced via the frequency dependent weights in the cost function to address the control effectiveness and robustness. The Hilbert-Huang transform (HHT) technique is further synthesized for online tuning of the controller gain adaptively to track the cable vibration evolution, which also obviates the iterative optimal gain selection for the trade-off between control performance and energy in the conventional time domain LQG (T-LQG) control. The developed adaptive frequency-shaped LQG (AF-LQG) control is realized by collocated self-sensing magnetorheological (MR) dampers considering the nonlinear damper dynamics for force tracking control. Performance of the AF-LQG control is numerically validated on a bridge cable transversely attached with a self-sensing MR damper. The results demonstrate the adaptivity in gain tuning of the AF-LQG control to target for the dominant cable mode for vibration energy dissipation, as well as its enhanced control efficacy over the optimal passive MR damping control and the T-LQG control for different excitation modes and damper locations.

Control of a Quarter-Car Model With Variable Damping

1999 ◽  
Author(s):  
G. Verros ◽  
S. Natsiavas ◽  
G. Stepan
Keyword(s):  
Control Strategy ◽  
Piecewise Linear ◽  
Damping Coefficient ◽  
Active System ◽  
Quarter Car Model ◽  
Car Model ◽  
Shock Absorbers ◽  
Car Suspension ◽  
Quarter Car ◽  
The Stability

Abstract Dynamics of a strongly nonlinear quarter-car model is investigated. The nonlinearity is due to a control strategy which selects the damping coefficient of the car suspension in a way that the resulting semi-active system approximates the performance of an active suspension system designed to produce sky-hook damping. According to this control strategy, the damping coefficient switches between two different positive values, leading to a piecewise linear dynamical model. For this model, the equation of motion is first presented in a general normalised form. Then, an appropriate methodology is applied for obtaining exact periodic motions for the case of forcing resulting from a road with harmonic profile. This methodology is based on employing the exact solution form within response intervals where the damping coefficients remain constant. The unknowns of the problem are then determined by imposing a set of periodicity and matching conditions. The stability analysis of the located motions is also performed by applying a method which is suitable for piecewise linear systems. Next, this analysis is applied and representative numerical results are obtained. Namely, response diagrams are presented, showing the effect of the important system parameters on the existence, amplitude and stability properties of various branches of periodic solutions. The results are also compared to those of the conventional suspension systems, including passive bilinear shock absorbers.

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