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

Author(s):  
K. H. Shirazi ◽  
S. M. M. Jaafari ◽  
M. Derakhshan ◽  
R. Shafie

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.

Author(s):  
Abolfazl Seifi ◽  
Reza Hassannejad ◽  
Mohammad Ali Hamed

In this study, a new method to improve ride comfort, vehicle handling, and workspace was presented in multi-objective optimization using nonlinear asymmetrical dampers. The main aim of this research was to provide suitable passive suspension based on more efficiency and the low cost of the mentioned dampers. Using the model with five degrees of freedom, suspension system parameters were optimized under sinusoidal road excitation. The main functions of the suspension system were chosen as objective functions. In order to better illustrate the impact of each objective functions on the suspension parameters, at first two-objective and finally five-objective were considered in the optimization problem. The obtained results indicated that the optimized viscous coefficients for five-objective optimization lead to 3.58% increase in ride comfort, 0.74% in vehicle handling ability, and 2.20% in workspace changes for the average of forward and rear suspension.


2008 ◽  
Vol 15 (5) ◽  
pp. 573-582 ◽  
Author(s):  
S.I. Ihsan ◽  
W.F. Faris ◽  
M. Ahmadian

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.


Author(s):  
Gurubasavaraju Tharehalli mata ◽  
Vijay Mokenapalli ◽  
Hemanth Krishna

This study assesses the dynamic performance of the semi-active quarter car vehicle under random road conditions through a new approach. The monotube MR damper is modelled using non-parametric method based on the dynamic characteristics obtained from the experiments. This model is used as the variable damper in a semi-active suspension. In order to control the vibration caused under random road excitation, an optimal sliding mode controller (SMC) is utilised. Particle swarm optimisation (PSO) is coupled to identify the parameters of the SMC. Three optimal criteria are used for determining the best sliding mode controller parameters which are later used in estimating the ride comfort and road handling of a semi-active suspension system. A comparison between the SMC, Skyhook, Ground hook and PID controller suggests that the optimal parameters with SMC have better controllability than the PID controller. SMC has also provided better controllability than the PID controller at higher road roughness.


Author(s):  
Daniel A. Tortorelli

Abstract Adjoint and direct differentiation methods are used to formulate design sensitivities for the steady-state response of damped linear elastodynamic systems that are subject to periodic loads. Variations of a general response functional are expressed in explicit form with respect to design field perturbations. Modal analysis techniques which uncouple the equations of motion are used to perform the analyses. In this way, it is possible to obtain closed form relations for the sensitivity expressions. This eliminates the need to evaluate the adjoint response and psuedo response (these responses are associated with the adjoint and direct differentiation sensitivity problems) over the time domain. The sensitivities need not be numerically integrated over time, thus they are quickly computed. The methodology is valid for problems with proportional as well as non-proportional damping. In an example problem, sensitivities of steady-state vibration amplitude of a crankshaft subject to engine firing loads are evaluated with respect to the stiffness, inertial, and damping parameters which define the shaft. Both the adjoint and direct differentiation methods are used to compute the sensitivities. Finite difference sensitivity approximations are also calculated to validate the explicit sensitivity results.


Author(s):  
George Valsamos ◽  
Christos Theodosiou ◽  
Sotirios Natsiavas

Dynamic response related to fatigue prediction of an urban bus is investigated. First, a quite complete model subjected to road excitation is employed in order to extract sufficiently reliable and accurate information in a fast way. The bus model is set up by applying the finite element method, resulting to an excessive number of degrees of freedom. In addition, the bus suspension units involve nonlinear characterstics. A step towards alleviating this difficulty is the application of an appropriate coordinate transformation, causing a drastic reduction in the dimension of the final set of the equations of motion. This allows the application of a systematic numerical methodology leading to direct determination of periodic steady state response of nonlinear models subjected to periodic excitation. Next, typical results were obtained for excitation resulting from selected urban road profiles. These profiles have either a known form or known statistical properties, expressed by an appropriate spatial power spectral density function. In all cases examined, the emphasis was put on investigating ride response. The main attention was focused on identifying areas of the bus suspension and frame subsystems where high stress levels are developed. This information is based on the idea of a nonlinear transfer function and provides the basis for applying suitable criteria in order to perform analyses leading to prediction of fatigue failure.


2015 ◽  
Vol 1115 ◽  
pp. 440-445 ◽  
Author(s):  
Musa Mohammed Bello ◽  
Amir Akramin Shafie ◽  
Raisuddin Khan

The main purpose of vehicle suspension system is to isolate the vehicle main body from any road geometrical irregularity in order to improve the passengers ride comfort and to maintain good handling stability. The present work aim at designing a control system for an active suspension system to be applied in today’s automotive industries. The design implementation involves construction of a state space model for quarter car with two degree of freedom and a development of full state-feedback controller. The performance of the active suspension system was assessed by comparing it response with that of the passive suspension system. Simulation using Matlab/Simulink environment shows that, even at resonant frequency the active suspension system produces a good dynamic response and a better ride comfort when compared to the passive suspension system.


Two wheelers like motorbikes and scooters are one of the major transports in India. In major cities and towns, it is most common private transport as it is fast and easy approach to the destination. But the prolonged drive in the two-wheeler leads to the potential health hazard and musco-skeletal disorder due to continuous exposure to the vibration caused during the ride and force transmitted to the vehicle body due to road irregularities. It is a challenge of automobile engineers to design a promising suspension system to overcome the risk of ride comfort during continuous driving. In this research, two-wheeler suspension system is modelled with a condition of bump and valley in a wavy road. The road surface is assumed to be wavy and the response of new suspension spring with different materials (stainless steel, tungsten and polymeric) along with viscous damper is analyzed and compared. By this analysis, it will be proposed to industry to modify the suspension system to improve its efficiency and reduce force transmitted to the human body to improve the ride comfort


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