附录APerformance Kinematics Simulation of Macpherson Suspension Based on ADAMSWANG Yuefang, WANG Zhenhua(Department of Vehicle & Power Engineering，College of MechatronicsEngineering,North University of China, Taiyuan, Shanxi, 030051, China) Phone:+863513920300Fax:+863513922364E-Mail:***********************.cnAbstract: The paper discusses a basic simulation way on founding a front suspension simulation model. It applies on method of multi-body dynamics and uses virtual prototyping technology software ADAMS building up Macpherson suspension entity mold. It analyzes the relations between a Macpherson suspension system and wheel alignment characteristic through kinematics simulation, and obtains the changing trend of the wheel alignment parameters. This provides theoretical foundation with further optimization design.Key words: Macpherson Suspension; Kinematics Simulation; ADAMS1. IntroductionSuspension system is a key part for cars, and has decisive effect on car drivability, stability, and comfortability. Because of its characteristics of simple structure, low cost and space economy, Macpherson suspension has become the most popular independent suspension since its emergence. Hence, the kinematics analysis of Macpherson suspension has great significance. ADAMS (Automatic Dynamic Analysis of Mechanical System) is a simulation software of mechanical system used most widely in the world. Based on the ADAMS virtual model technology, the automobile suspension is regard as a multi-body system which parts connect and motion each other. With the help of ADAMS/View, this paper established multi-body dynamics model of Macpherson front suspension of some car which is increasingly wide used in modern car, and the effects of suspension parameters when wheel travel or turn were studied. The ADAMS entity numeric suspension kinetics simulation provides an efficient and updated tool for developing suspension system.2. Simulation model2.1 Front suspension subsystem simulation modelFirstly, three-dimensional model of Macpherson suspension system in the Pro/E according to acquired geometric parameters is established. Secondly, ADAMS/CAR model is imported by utilizing MECHANISM/Pro, and the geometric characteristicparameters can be obtained from Pro/E three-dimensional documents. The founding model time is short and very accurate. Fig.1 is the model of Macpherson suspension subsystem. Table 1 is the constraints relationship between rigid bodies of front Macpherson suspension.Fig.1 Front Macpherson suspension subsystem1-lower triangle swinging arm 2-universal joint3-subsidiary car frame4-upper suspension support 5-tie rod 6-wheel rim 7-driving axle8-driving joint axle9-shock absorber 10-rubber liner2.2 Steering subsystem simulation modelGear and rack steering system model adopts partial coordinate system. The base point lies in center of circle of steering wheel. The direction of x, y, z axle is radial, tangential, normal of steering wheel separately. Figure 2 is the model which contains six rigid bodies that are rack, rack shell, gear axle, middle axle, steering limb and steering wheel axle. Three assembled bodies connect tie rod, subsidiary car frame and car body. Fig.2 is the model of steering system. Table 2 is the constraints relationship between rigid bodies of steering subsystem.Fig.2 The model of steering subsystem2.3 Simulation model of front Macpherson suspension systemFront Macpherson suspension subsystem and steering subsystem models from ADAMS/CAR that have been established are invoked. Then, combined parameters are input. So far , front Macpherson suspension model is finished. Figure 3 is the kinematics simulation model of Macpherson suspension.Fig.3 Suspension simulation model3. Kinematics simulation analyses3.1 Data processInitial simulation conditions uniform actual parameters of the researched car. Utilizing ADAMS/CAR model simulates bilateral parallel travel and opposite direction travel. So, the alteration of camber angle, kingpin inclination angle, caster angle and toe angle are analyzed. The structure of Macpherson suspension’s left and right is symmetrical, it is totally the same to alignment parameters, only the left wheel alignment parameters are analyzed[3]. The range that this car beats is 150mm -130mm actually. Under two kinds of operating modes, the comparison of changed curves on wheel alignment parameters are shown in Fig. 4-7.Fig.4 Camber angle vs wheel travelFig.5 Caster angle vs wheel travelFig.6 Toe angle vs wheel travelFig.7 Kingpin inclination angle vs wheel travel3.2 Discussion and analysis(1)In the process of wheel parallel travel and opposite travel, the alignment parameters change with the change of wheel vertical shift. In Fig.4, camber angle reduces firstly and increases secondly. The changing amount is 0.9786. The change of camber angle contains two parts: the change of camber angle that comes from car body roll and the changing amount of camber angle that relates car body travel. In Fig.5, the change of caster angle with the wheel vertical shift rise sharply.(2)Under two kinds of operating modes of wheel parallel travel and opposite travel, Fig.6 is shown , the change of toe angle is obviously. Under the operating modes of opposite travel, toe angle increases from -0.8029 to 1.6844. Its change affects car drivability and stability.(3)As we can see in Fig.4 and Fig.7, when the wheel travels downward, the change range that is from 0～-130mm, the changing trend of kingpin inclination angle is opposite to camber angle. This could aggravate the wheel wear. But, according to the theoretical relationship and adjust, proper and acceptedcorresponding relation can be obtained.4. ConclusionThis paper discusses kinematics simulation analysis on founding a front Macpherson suspension simulation model that uses technology software ADAMS. Three conclusions are as follows:(1)ADAMS/CAR model is imported from Pro/E by utilizing MECHANISM/Pro, but model can also be imported to SolidWork or UG in STEP format, then, imported to ADAMS in ParaSolid format.(2)The original wheel orientation parameters of Macpherson suspension meet the require. These indicate that the model is rational. The wheel wear range is accepted.(3)The change trend of the wheel alignment parameters is gained through kinematics simulation analysis of Macpherson suspension. Wheel alignment characteristic has effect on full-vehicle capability through suspension and Camber angle. On contrary, full-vehicle motion characteristic affects wheel alignment characteristic through suspension. In a word, virtual prototyping technology software ADAMS can greatly predigest design program and shorten exploitive cycle, greatly reduce exploitive expense and cost, clearly improve product quality and system capability to get optimized and innovated product.附录B基于ADAMS的麦弗逊悬架运动学仿真分析王月芳，王振华（中北大学车辆与动力工程系, 山西太原030051)摘要：本文讨论了一种建立麦弗逊前悬架模型的基本仿真分析方法。
