When designing vehicle suspension systems, compromises are usually made when setting the range of values for spring stiffness and damping constant. Suspension parameters are set depending on the operational requiremen...When designing vehicle suspension systems, compromises are usually made when setting the range of values for spring stiffness and damping constant. Suspension parameters are set depending on the operational requirements of the market. Passenger car for example, would require high quality damping while off road vehicle requires high spring stiffness setting. A quarter vehicle suspension model has been used to study the suspension transmissibility in handling and ride at various frequency ratios. The results obtained show that as the frequency ratio increases, transmissibility for handling reduces with increasing suspension stiffness and increases as the damping constant is increased. On the other hand, transmissibility for ride deteriorate as the spring constant is increased but approaches the ideal as the damping constant is increased. The dynamic magnification of the sprung masses reduces while that of the unsprung masses improves as the frequency ratio is increased.展开更多
为使超微型汽车在各簧载质量下都能获得相对较好的平顺性能,建立了质心随乘载质量不同而变化的半车5自由度动力学模型,提出了1种基于车辆实际乘载情况统计结果的多目标二维度模拟退火优化方法.该方法以各种乘载情况下座椅质量加速度、...为使超微型汽车在各簧载质量下都能获得相对较好的平顺性能,建立了质心随乘载质量不同而变化的半车5自由度动力学模型,提出了1种基于车辆实际乘载情况统计结果的多目标二维度模拟退火优化方法.该方法以各种乘载情况下座椅质量加速度、前后悬架动行程、前后轮胎动位移和车身动态姿态的加权和作为优化目标,以前后悬架刚度和阻尼系数作为优化变量.对优化前后数据进行仿真对比,得到车速为50 km.h-1,乘载为75,150 kg 2种工况下,座椅质量加速度分别优化了17.53%和19.06%,并且其他性能参数能够满足性能要求.试验结果验证了所建仿真模型的正确性及所提出优化方法的有效性,优化后车辆在不同车速和乘载工况下,舒适性降低界限时间有所提高,车辆平顺性得到一定程度的改善.展开更多
The current research of suspension performance evaluation is mixed in the evaluation of vehicle handling and ride comfort. However, it is lack of a direct and independent evaluation method for suspension performance. ...The current research of suspension performance evaluation is mixed in the evaluation of vehicle handling and ride comfort. However, it is lack of a direct and independent evaluation method for suspension performance. In this paper, a novel wheel turn center method is proposed to evaluate the suspension performance. This method is based on the concept and application of wheel turn center （WTC） and sprung mass turn center （SPTC）. The vehicle body and each wheel are regarded to be independent rigid bodies and have their own turn centers which reflect respective steering motions and responses. Since the suspension is the link between vehicle body and wheels, the consistence between the sprung mass turn center and the wheel turn center reflects the effect and performance of the suspension system. Firstly, the concept and appropriate calculation method of WTC and SPTC are developed. Then the degree of inconsistence between WTC and SPTC and the time that they achieve consistence, when the vehicle experiences from transient steering to steady steering state, are proposed to evaluate suspension performance. The suspension evaluation tests are conducted under different vehicle velocities and lateral accelerations by using CarSim software. The simulation results show that the inconsistence of steering motion between vehicle body and wheels are mainly at high speeds and low lateral accelerations. Finally, based on the proposed evaluation indexes, the influences of different suspension characteristic parameters on suspension performance and their matches to improve steering coordination are discussed. The proposed wheel turn center method provides a guidance and potential application for suspension evaluation and optimization.展开更多
文摘When designing vehicle suspension systems, compromises are usually made when setting the range of values for spring stiffness and damping constant. Suspension parameters are set depending on the operational requirements of the market. Passenger car for example, would require high quality damping while off road vehicle requires high spring stiffness setting. A quarter vehicle suspension model has been used to study the suspension transmissibility in handling and ride at various frequency ratios. The results obtained show that as the frequency ratio increases, transmissibility for handling reduces with increasing suspension stiffness and increases as the damping constant is increased. On the other hand, transmissibility for ride deteriorate as the spring constant is increased but approaches the ideal as the damping constant is increased. The dynamic magnification of the sprung masses reduces while that of the unsprung masses improves as the frequency ratio is increased.
文摘为使超微型汽车在各簧载质量下都能获得相对较好的平顺性能,建立了质心随乘载质量不同而变化的半车5自由度动力学模型,提出了1种基于车辆实际乘载情况统计结果的多目标二维度模拟退火优化方法.该方法以各种乘载情况下座椅质量加速度、前后悬架动行程、前后轮胎动位移和车身动态姿态的加权和作为优化目标,以前后悬架刚度和阻尼系数作为优化变量.对优化前后数据进行仿真对比,得到车速为50 km.h-1,乘载为75,150 kg 2种工况下,座椅质量加速度分别优化了17.53%和19.06%,并且其他性能参数能够满足性能要求.试验结果验证了所建仿真模型的正确性及所提出优化方法的有效性,优化后车辆在不同车速和乘载工况下,舒适性降低界限时间有所提高,车辆平顺性得到一定程度的改善.
基金Supported by Changjiang Scholar and Innovative Research Team Plan of China(Grant No.IRT0626)
文摘The current research of suspension performance evaluation is mixed in the evaluation of vehicle handling and ride comfort. However, it is lack of a direct and independent evaluation method for suspension performance. In this paper, a novel wheel turn center method is proposed to evaluate the suspension performance. This method is based on the concept and application of wheel turn center （WTC） and sprung mass turn center （SPTC）. The vehicle body and each wheel are regarded to be independent rigid bodies and have their own turn centers which reflect respective steering motions and responses. Since the suspension is the link between vehicle body and wheels, the consistence between the sprung mass turn center and the wheel turn center reflects the effect and performance of the suspension system. Firstly, the concept and appropriate calculation method of WTC and SPTC are developed. Then the degree of inconsistence between WTC and SPTC and the time that they achieve consistence, when the vehicle experiences from transient steering to steady steering state, are proposed to evaluate suspension performance. The suspension evaluation tests are conducted under different vehicle velocities and lateral accelerations by using CarSim software. The simulation results show that the inconsistence of steering motion between vehicle body and wheels are mainly at high speeds and low lateral accelerations. Finally, based on the proposed evaluation indexes, the influences of different suspension characteristic parameters on suspension performance and their matches to improve steering coordination are discussed. The proposed wheel turn center method provides a guidance and potential application for suspension evaluation and optimization.
