麦弗逊悬架系统仿真分析应用研究

汽车悬架类型的选择和悬架参数的差异对汽车的操纵稳定性和行驶平顺性具有重要的影响。主要分析了麦弗逊悬架的结构特点,并通过CATIA和ADAMS软件建立麦弗逊悬架的3D模型,对其进行仿真分析,得出悬架参数的优化设计方法。     

汽车磁流变非线性悬架模糊控制

建立了整车悬架系统的三维模型,根据试验数据得出了前后悬架弹簧的非线性特性曲线。前后悬架减振器均采用磁流变减振器,采用Bouc-Wen参数化模型为其阻尼力模型。采用模糊控制算法为整车半主动控制算法,采用ADAMS和Matlab联合对整车平顺性进行仿真。结果表明,采用模糊控制算法控制磁流变非线性悬架可提高整车的平顺性。     

主动汽车悬架的非线性控制

本文采用１／４车模型对天棚阻尼器和主动悬架的动力学性能进行分析，针对执行器的非线性特性，探讨了微分几何法和反馈法线必互法在主动悬架控制中的应用，在系统控制设计中采用了离散滑模法，仿真结果显示非线性控制律能有效地改善主动悬架的隔振特性。     

An efficient sensitivity analysis method for modified geometry of Macpherson suspension based on Pearson correlation coefficient

The main purpose of this paper is to propose a new method for designing Macpherson suspension, based on the Sobol indices in terms of Pearson correlation which determines the importance of each member on the behaviour of vehicle suspension. The formulation of dynamic analysis of Macpherson suspension system is developed using the suspension members as the modified links in order to achieve the desired kinematic behaviour. The mechanical system is replaced with an equivalent constrained links and then kinematic laws are utilised to obtain a new modified geometry of Macpherson suspension. The equivalent mechanism of Macpherson suspension increased the speed of analysis and reduced its complexity. The ADAMS/CAR software is utilised to simulate a full vehicle, Renault Logan car, in order to analyse the accuracy of modified geometry model. An experimental 4-poster test rig is considered for validating both ADAMS/CAR simulation and analytical geometry model. Pearson correlation coefficient is applied to analyse the sensitivity of each suspension member according to vehicle objective functions such as sprung mass acceleration, etc. Besides this matter, the estimation of Pearson correlation coefficient between variables is analysed in this method. It is understood that the Pearson correlation coefficient is an efficient method for analysing the vehicle suspension which leads to a better design of Macpherson suspension system.     

Designing a non-linear tracking controller for vehicle active suspension systems using an optimization process

In this paper, a new non-linear tracking controller for vehicle active suspension systems is analytically designed using an optimization process. The proposed scheme employs a realistic non-linear quarter-car model, which is composed of a hardening spring and a quadratic damping force. The control input is the external active suspension force and is determined by minimizing a performance index defined as a weighted combination of conflicting objectives, namely ride quality, handling performance and control energy. A linear skyhook model with standard parameters is used as the reference model to be tracked by the controller. The robustness of the proposed controller in the presence of modeling uncertainties is investigated. The performed analysis and the simulation results indicate that both vehicle ride comfort and handling performance can be improved using the minimum external force when the proposed non-linear controller is engaged with the model. Meanwhile, a compromise between different objectives and control energy can easily be made by regulating their respective weighting factors, which are the free parameters of the control law.     

Application of Nonlinear Control Theory to Electronically Controlled Suspensions

This paper illustrates the use of nonlinear control theory for designing electro-hydraulic active suspensions. A nonlinear, “sliding” control law is developed and compared with the linear control of a quarter-car active suspension system acting under the effects of coulomb friction. A comparison will also be made with a passive quarter-car suspension system. Simulation and experimental results show that nonlinear control performs better than PID control and improves the ride quality compared to a passive suspension.     

Accumulated tolerance analysis of suspension by geometric tolerances based on multibody elasto-kinematic analysis

Tolerance design of vehicle suspension is an important factor that affects the ride and handling quality and cost of the vehicle. Also, applying geometric tolerance to an analysis model is found to be a difficult process. This paper presents a method for tolerance analysis of wheel alignment of vehicle suspension. Monte-Carlo simulation method is applied to multibody elasto-kinematic model to analyze the accumulated geometric tolerances. As an example, Macpherson Strut Type front half car model is used, and wheel alignment dispersion and contribution ratio to the dispersion by accumulated geometric tolerances is computed. This paper also presents an efficient modeling and analysis method for elasto-kinematic model of vehicle suspensions by computing the stiffness matrix analytically. The simulation results of a Macpherson Strut Type demonstrates the validity and accuracy of the proposed method.     

工程车辆非线性橡胶悬架动力学建模与优化

以AD250铰接式自卸车的非线性变刚度橡胶悬架为研究对象,应用模态综合法和多柔体系统动力学理论,并通过整车试验建立了整车刚柔耦合动力学模型。以行驶平顺性和操纵稳定性为优化目标,采用序列二次规划法,对不同载荷、不同等级路面和不同车速下的悬架特性参数进行优化,得到了不同工况下的最优悬架特性参数。通过最小二乘法拟合得到了橡胶悬架刚度参数的理想非线性特性曲线。仿真结果表明,优化后的橡胶悬架系统能使车辆保持良好的行驶平顺性。     

液压主动悬架的非线性自适应控制

以车身垂直加速度和悬架动行程为控制目标，同时引入非线性高通滤波器和非线性低通滤波器，基于逆向递推(Backstepping)技术，并考虑液压系统的非线性特性及其参数不确定性，提出了一种主动悬架的非线性自适应控制方法。仿真结果表明，在不同的激励信号作用下，都取得了较好的控制效果。     

Application of Nonlinear Control Theory to Electronically Controlled Suspensions

SUMMARY

This paper illustrates the use of nonlinear control theory for designing electro-hydraulic active suspensions. A nonlinear, “sliding” control law is developed and compared with the linear control of a quarter-car active suspension system acting under the effects of coulomb friction. A comparison will also be made with a passive quarter-car suspension system. Simulation and experimental results show that nonlinear control performs better than PID control and improves the ride quality compared to a passive suspension.     

半主动悬架磁流变液减振器研究

针对Passat B5轿车前悬架,开发了双筒滑阀式磁流变液减振器,提出了簧载质量的绝对速度及其与非簧载质量间的相对运动速度估计算法,利用实测悬架参数和磁流变液减振器的非线性阻尼力特性,建立了带磁流变液减振器的半主动悬架模型。沥青路面试验结果表明:相对于被动悬架,采用磁流变液半主动悬架后车辆平顺性改善大于10%。     

Prediction of ride quality of a Maglev vehicle using a full vehicle multi-body dynamic model

In magnetically levitated (Maglev) transportation systems, especially in electromagnetic suspension system (EMS) type Maglev systems, highly accurate prediction of ride quality is very important in order to reasonably relax guideway construction tolerances or constraints and stiffness while meeting the specification for ride comfort, thereby reducing guideway construction and maintenance costs. A full vehicle multi-body dynamic model is proposed, to facilitate a rigorous ride quality prediction of an EMS-type Maglev vehicle. Using the more realistic dynamic model proposed in this paper, the effects of guideway deflection limits, surface roughness, and levitation control system parameters on ride quality are studied numerically. The results obtained from the simulation studies are then used to facilitate a discussion of the trade-off between guideway smoothness and vehicle suspension. It can be expected that these studies could suggest cost-effective specifications for guideway construction tolerances and stiffness and EMS.     

Sliding mode observation and control for semiactive vehicle suspensions

This paper investigates the application of robust, nonlinear observation and control strategies, namely sliding mode observation and control (SMOC), to semiactive vehicle suspensions using a model reference approach. The vehicle suspension models include realistic nonlinearities in the spring and magnetorheological (MR) damper elements, and the nonlinear reference models incorporate skyhook damping. Since full state measurement is difficult to achieve in practice, a sliding mode observer (SMO) that requires only suspension deflection as a measured input is developed. The performance and robustness of sliding mode control (SMC), SMO, and SMOC are demonstrated through comprehensive computer simulations and compared to popular alternatives. The results of these simulations reveal the benefits of sliding mode observation and control for improved ride quality, and should be directly transferable to commercial semiactive vehicle suspension implementations.     

Roll and pitch independently tuned interconnected suspension: modelling and dynamic analysis

In this paper, a roll and pitch independently tuned hydraulically interconnected passive suspension is presented. Due to decoupling of vibration modes and the improved lateral and longitudinal stability, the stiffness of individual suspension spring can be reduced for improving ride comfort and road grip. A generalised 14 degree-of-freedom nonlinear vehicle model with anti-roll bars is established to investigate the vehicle ride and handling dynamic responses. The nonlinear fluidic model of the hydraulically interconnected suspension is developed and integrated with the full vehicle model to investigate the anti-roll and anti-pitch characteristics. Time domain analysis of the vehicle model with the proposed suspension is conducted under different road excitations and steering/braking manoeuvres. The dynamic responses are compared with conventional suspensions to demonstrate the potential of enhanced ride and handling performance. The results illustrate the model-decoupling property of the hydraulically interconnected system. The anti-roll and anti-pitch performance could be tuned independently by the interconnected systems. With the improved anti-roll and anti-pitch characteristics, the bounce stiffness and ride damping can be optimised for better ride comfort and tyre grip.     

Sliding mode observation and control for semiactive vehicle suspensions

This paper investigates the application of robust, nonlinear observation and control strategies, namely sliding mode observation and control (SMOC), to semiactive vehicle suspensions using a model reference approach. The vehicle suspension models include realistic nonlinearities in the spring and magnetorheological (MR) damper elements, and the nonlinear reference models incorporate skyhook damping. Since full state measurement is difficult to achieve in practice, a sliding mode observer (SMO) that requires only suspension deflection as a measured input is developed. The performance and robustness of sliding mode control (SMC), SMO, and SMOC are demonstrated through comprehensive computer simulations and compared to popular alternatives. The results of these simulations reveal the benefits of sliding mode observation and control for improved ride quality, and should be directly transferable to commercial semiactive vehicle suspension implementations.     

An Original Feedback Control with a Reversible Electromechanical Actuator Used as an Active Isolation System for a Seat Suspension. Part II: Experimental Study

From the theoretical study presented in [1], we investigate the experimental feasibility of the active seat suspension to improve ride comfort. The prototype of the reversible electromechanical actuator used in the active seat suspension is presented. First, the kinematic guide with a vertical auto-levelling system is described. Second, the electromechamical actuator and the power drive transmission are presented. It is noticed that the prototype design is achieved with a systemic approach taking into account the industrial constraints. Then, the laboratory experimental setup is described. Several tests are performed on the prototype for model validation and performance purposes. Correct force feedback control in the actuator is verified. The real performances of the active seat suspension on a prototype is investigated for different pertubation inputs. Experimental results clearly show the efficiency of the active seat suspension to improve passenger comfort and demonstrate its feasability.     

Railway Vehicle Active Suspensions

This paper reviews the state-of-the-art of active suspensions for use on railway vehicles. The primary focus of the paper is on ride quality control, both vertical and lateral, and on lateral stability control.

The section on theoretical considerations summarizes the results of a one-degree of freedom optimization and then investigates analytically the use of active suspensions for lateral ride and stability augmentation. It is shown that separate control structures using different measurements and actuator actions are very effective in controlling both ride quality and stability.

A section on a survey ofcurrent activities reviews published research on active railway suspension work around the world.

Finally a concluding section indicates future trends in active suspension applications.     

油气主动悬架非线性模型的建立、仿真与试验验证

本文通过分析油气悬架中存在的气体弹簧刚度非线性特性和摩擦力，建立了主动悬架的非线性模型。分析了悬架的非线性特性对悬架运动的影响。仿真和试验结果表明，非线性模型比线性模型更接近油气悬架的实际情况，根据非线性模型设计的车身高度控制策略比根据线性模型设计的控制策略具有更好的控制效果。     

An Original Feedback Control with a Reversible Electromechanical Actuator Used as an Active Isolation System for a Seat Suspension. Part II: Experimental Study

From the theoretical study presented in [1], we investigate the experimental feasibility of the active seat suspension to improve ride comfort. The prototype of the reversible electromechanical actuator used in the active seat suspension is presented. First, the kinematic guide with a vertical auto-levelling system is described. Second, the electromechamical actuator and the power drive transmission are presented. It is noticed that the prototype design is achieved with a systemic approach taking into account the industrial constraints. Then, the laboratory experimental setup is described. Several tests are performed on the prototype for model validation and performance purposes. Correct force feedback control in the actuator is verified. The real performances of the active seat suspension on a prototype is investigated for different pertubation inputs. Experimental results clearly show the efficiency of the active seat suspension to improve passenger comfort and demonstrate its feasability.