scholarly journals Analysis of Control Policies and Dynamic Response of a Q-Car 2-DOF Semi Active System

2008 ◽  
Vol 15 (5) ◽  
pp. 573-582 ◽  
Author(s):  
S.I. Ihsan ◽  
W.F. Faris ◽  
M. Ahmadian
Keyword(s):  
Ride Comfort ◽  
Hybrid Control ◽  
Control Policy ◽  
Active System ◽  
Passenger Cars ◽  
Control Policies ◽  
The Road ◽  
Steady State Responses ◽  
State Responses ◽  
Transient And Steady State

Several control policies of Q-car 2-DOF semiactive system, namely skyhook, groundhook and hybrid controls are presented. Their ride comfort, suspension displacement and road-holding performances are analyzed and compared with passive system. The analysis covers both transient and steady state responses in time domain and transmissibility response in frequency domain. The results show that the hybrid control policy yields better comfort than a passive suspension, without reducing the road-holding quality or increasing the suspension displacement for typical passenger cars. The hybrid control policy is also shown to be a better compromise between comfort, road-holding and suspension displacement than the skyhook and groundhook control policies.

Road-Holding and Ride Performance Optimization Using Bee’s Algorithm

2011 ◽  
Author(s):  
K. H. Shirazi ◽  
S. M. M. Jaafari ◽  
M. Derakhshan ◽  
R. Shafie
Keyword(s):  
Performance Optimization ◽  
Ride Comfort ◽  
Equations Of Motion ◽  
Interaction Model ◽  
Suspension System ◽  
Objective Functions ◽  
Passenger Cars ◽  
State Response ◽  
Dimensional Parameters ◽  
Transient And Steady State

This paper provides a method for optimal synthesis of the passenger cars suspension system to obtain the best road-holding as well as ride-comfort characteristics. The longitudinal vehicle model consists of sprung and unsprung masses, tire-ground interaction model, and suspension system kinematics. Defining the non-dimensional parameters the equations of motion of the system are derived in the non-dimensional form. Several objective functions are defined for the optimization of road-holding and ride comfort characteristics based on the transient and steady-state response of the sprung mass, respectively. The optimization variables are position of instant centers of rotation of the wheels with respect to the sprung mass. Bee’s algorithm is used to obtain the solutions of the problem. The best position for the instant centers of front and rear suspension linkages are obtained and compared with 100% anti-squat line.

In Search of a Suitable Control Policy for Intelligent Vehicle Suspensions

2002 ◽  
Author(s):  
Fernando D. Goncalves ◽  
Mehdi Ahmadian
Keyword(s):  
Steady State ◽  
Hybrid Control ◽  
Control Policy ◽  
Control Technique ◽  
Intelligent Vehicle ◽  
Alternative Control ◽  
Control Policies ◽  
Peak Displacement ◽  
Vehicle Suspensions ◽  
Magneto Rheological

Many control policies, such as skyhook and groundhook control, are now being considered for intelligent vehicle suspensions. Past studies have shown the performance limitations of these policies, as well as others that have been considered for vehicle applications. The performance of three semi-active control policies were studied experimentally under steady-state and transient inputs. Experimental results were obtained using a quarter-car rig and a magneto-rheological damper. The commonly considered skyhook and groundhook control policies were employed and evaluated under a steady-state, or pure tone, input and a transient, or step input. An alternative control technique called “hybrid control,” which attempts to merge the performance benefits of skyhook and groundhook control was also considered. Peak-to-peak displacement and peak-to-peak acceleration were used to evaluate performance. The results indicate that while skyhook and groundhook can offer benefits to either the sprung or unsprung masses, hybrid control can offer benefits to both masses. The compromise inherent in both skyhook and groundhook is eliminated with the use of hybrid control. Both the steady-state and transient dynamics of the sprung and unsprung masses can be reduced below those of passive using hybrid control with an α of 0.5. This corresponds to equal contributions from skyhook control and groundhook control.

EVALUATION OF DYNAMIC PERFORMANCE OF MAGENETO-RHEOLOGICAL DAMPER BY VIRTUAL PROTOTYPE TECHNOLOGY

2005 ◽  
Vol 19 (07n09) ◽  
pp. 1542-1548 ◽  
Author(s):  
BAOLIN HOU ◽  
JIONAG WANG
Keyword(s):  
Dynamic Characteristics ◽  
Dynamic Performance ◽  
Mr Damper ◽  
Control Policy ◽  
Virtual Prototype ◽  
Control Policies ◽  
The Road ◽  
Full Vehicle ◽  
Road Profile ◽  
Virtual Prototype Technology

Numerical dynamic simulation of a full vehicle incorporating a magneto-rheological damper in the primary suspension is studied using the package ADAMS and SIMULINK. The full vehicle model is built under ADAMS. The interaction between the tire and the road profile is simulated using the ADAMS/TIRE capabilities. The UA tire model is used to model the dynamic characteristics of the tires. A 3-D road profile model is built based on the spatial power spectrum density of a random road profile. In order to model the dynamic characteristics of the primary suspension MR damper, a non-parametric model of an MR damper is proposed which can conveniently be incorporated into the vehicle dynamic model. Two kinds of control policies, a common skyhook and the so-called non-jerk skyhook, are adopted to control the current applied to the MR damper. The simulation results imply that either one of the two skyhook control policies can obtain a good compromise between so-called "soft damping" and "hard damping", and non-jerk skyhook control policy can curb some higher frequency components which are observed in the acceleration response of the chassis. This study demonstrates that virtual prototype technology is an effective approach for investigating the dynamic behavior of MR dampers for complex systems.

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