adams路面文件
ADAMS路面模型和轮胎UA模型中各全参数含义
2D Road TypesThe available road types are:•DRUM - Tire test drum (requires a zero-speed-capable tire model). •FLAT - Flat road.•PLANK - Single plank perpendicular, or in oblique direction relative to x-axis, with or without bevel edges. • POLY_LINE - Piece-wise linear description of the road profile. The profiles for the left and right track are independent. •POT_HOLE - Single pothole of rectangular shape. •RAMP - Single ramp, either rising or falling. •ROOF - Single roof-shaped, triangular obstacle. •SINE - Sine waves with constant wave length. •SINE_SWEEP - Sine waves with decreasing wave lengths.•STOCHASTIC_UNEVEN - Synthetically generated irregular road profiles that match measured stochastic properties of typical roads. The profiles for left and right track are independent, or may have a certain correlation. Examples of 2D RoadsSample files for all the road types for Adams/Car are in the standard Adams/Car database:install_dir /shared_car_database.cdb/roads.tbl/Sample files for all the road types for Adams/Tire are in: install_dir /solver/atire/Sample files for all the road types for Adams/Chassis are in: install_dir /achassis/examples/rdf/Note that you must select a specific contact method, such as point-follower or equivalent plane, to define how the roads will interact with the tires. Not allcombinations of road, tire, and contact methods are permitted. Allowable combinations are explained in Tire Models help under the description of the specific tire model.2D Road Model ParametersThe [PARAMETERS] block must contain the following data, some of which are independent of the type of road. Learn about parameters:•Independent of Road Type •Drum •Flat •Plank •Polyline•Pothole•Ramp•Roof•Sine•Sweep•Stochastic UnevenParameters Independent of Road TypeThe following parameters are required regardless of the road type.If ROAD_TYPE = drum, then define the following parameters:If ROAD_TYPE = flat, then no further parameters are required.Parameters for Road Type of PlankIf ROAD_TYPE = plank, then define the following parameters:If ROAD_TYPE = poly_line, then the [PARAMETERS] block must have a (XZ_DATA) subblock. The subblock consists of three columns of numerical data:•Column one is a set of x-values in ascending order.•Columns two and three are sets of respective z-values for left and right track.The following is an example of the full [PARAMETERS] Body for a road type of polyline: $---------------------------PARAMETERS[PARAMETERS]OFFSET = 0ROTATION_ANGLE_XY_PLANE = 180$(XZ_DATA)0 0 01000 100 502000 -1000 1003000 -100 1003001 50 04000 -100 100The XZ_DATA subblock can be extremely large. In this case, only the portion that is needed at the moment is loaded. To facilitate efficient reloading while simulation is running, do not use any comment lines in a subblock that contains more than 2000 lines. Parameters for Road Type of PotholeIf ROAD_TYPE = pot_hole, then the parameters are:If ROAD_TYPE = ramp, then the parameters are:If ROAD_TYPE = roof, then the parameters are:If ROAD_TYPE = sine, then the parameters are:amplitude Amplitude of sine wave (a).wave_lengthWave length of sine wave ().start Start of sine waves (traveldistance) (s s).The road height, z, is given by:Parameters for Road Type of Stochastic UnevenA stochastic uneven road profile both for left and right wheels is generated, with properties very close to measured road profiles.In a first step, discrete white noise signals are formed on the basis of nearly uniformly distributed random numbers. Two of these numbers are assigned to every 10 mm of travel path. The distribution of these random numbers is approximated by summing several equally distributed random numbers, taking advantage of the ‘law of large numbers’ of mathematical statistics.Next, these values are integrated with respect to travel distance, using a simplefirst order time-discrete integration filter. The independent variable of that filter is not time, but travel path. That is why the filter cutoff frequency is controlled by a path constant instead of a time constant. The filter process results in two approximate realizations of white velocity noise; that is, two signals, thederivatives of which are close to white noise. Signals with that property are known as road profiles with waviness 2. Several investigations in the past showed that the waviness derived from measured road spectral densities ranges from about 1.8 to 2.2. The last step is to linearly combine the two realizations of the aboveprocess:,, resulting in the left and right profile,. This is done such that the two signals are completely independent if , and identical if:If ROAD_TYPE = stochastic_uneven, then the parameters are:The parameter: Indicates:intensity Variable to control intensity of white velocity noise, whichapproximates measured spectra of road profiles fairly well.path_constant Variable to control high-pass integration filter.correlation_rl Variable to control correlation between left and right track:•If 0, no correlation.•If 1, complete correlation (that is, left track = right track). Can be any value between 0 and 1.startStart of unevenness (travel distance).Parameters for Road Type of SweepIf ROAD_TYPE = sine_sweep, then the parameters are:[PARAMETERS] Data for Road Type of Sine Sweep The parameter: Indicates:start Start of swept sine wave (travel distance) (). endEnd of swept sine wave (travel distance) ().amplitude_at_sta rtAmplitude of swept sine wave at start travel distance (). amplitude_at_end Amplitude of swept sine wave at end travel distance ().wave_length_at_s tartWave length of swept sine wave a start travel distance ().wave_length_at_e ndWave length of swept sine wave at end travel distance. Must be less than or equal to wave_length_at_start ().sweep_type•sweep_type = 0: frequency increases linearly with respect to travel distance. •sweep_type = 1: wave length decreases by a constant factor per cycle. Depending on the value of sweep_type, the road height is given by the following functions, where:• Linear sweep: (sweep_type = 0) The frequency increases linearly with respect to travel distance. The road height value z (s) as function of travel distance s is alculated as follows:Note the factor 2 in the denominator is not an error. The actual frequency (= derivative of the sine function argument with respect to travel path, divided by ; this is not equal to that factor that is multiplied by in the sine function) is given by thefollowing:•Logarithmic sweep: (sweep_type = 1) with every cycle, the wave length decreases by a constant factor. The road height value is calculated as follows:where:is the travel path where theoretically an infinitely high frequency was reached, measured relative to sweep start . Theactual frequency is given by:Using the UA-Tire ModelLearn about using the University of Arizona (UA) tire model:•Background Information •Tire Model Parameters •Force Evaluation •Operating Mode: USE_MODE •Tire Carcass Shape •Property File Format ExampleBackground Information for UA-TireThe University of Arizona tire model was originally developed by Drs. P.E. Nikravesh and G. Gim. Reference documentation: G. Gim, Vehicle Dynamic Simulation with aComprehensive Model for Pneumatic Tires, PhD Thesis, University of Arizona, 1988. The UA-Tire model also includes relaxation effects, both in the longitudinal and lateral direction.The UA-Tire model calculates the forces at the ground contact point as a function of the tire kinematic states, see Inputs and Output of the UA-Tire Model. A description of the inputs longitudinal slip k, side slip a and camber angle can be found in About Tire Kinematic and Force Outputs. The tire deflection and deflection velocity are determined using either a point follower or durability contact model. For more information, see Road Models in Adams/Tire . A description of outputs, longitudinal force Fx, lateral force Fy, normal force Fz, rolling resistance moment My and self aligningmoment Mz is given in About Tire Kinematic and Force Outputs. The required tire model parameters are described in Tire Model Parameters.Inputs and Output of the UA-Tire ModelDefinition of Tire Slip QuantitiesSlip Quantities at Combined Cornering and Braking/TractionThe longitudinal slip velocity Vsx in the SAE-axis system is defined using thelongitudinal speed Vx, the wheel rotational velocity , and the effective rolling radius Re:The lateral slip velocity is equal to the lateral speed in the contact point with respect to the road plane:The practical slip quantities (longitudinal slip) and (slip angle) are calculated with these slip velocities in the contact point:When the UA Tire is used for the force calculation the slip quantities during positive Vsx (driving) are defined as:The rolling speed Vr is determined using the effective rolling radius Re:Note that for realistic tire forces the slip angle is limited to 45 degrees and thelongitudinal slip Ss (= ) in between -1 (locked wheel) and 1.Lagged longitudinal and lateral slip quantities (transient tire behavior)In general, the tire rotational speed and lateral slip will change continuously because of the changing interaction forces in between the tire and the road. Often the tire dynamic response will have an important role on the overall vehicle response. For modeling this so-called transient tire behavior, a first-order system is used both forthe longitudinal slip as the side slip angle, . Considering the tire belt as a stretched string, which is supported to the rim with lateral spring, the lateral deflection of the belt can be estimated (see also reference [1]). The figure below shows a top-view of the string model.Stretched String Model for Transient Tire BehaviorWhen rolling, the first point having contact with the road adheres to the road (no sliding assumed). Therefore, a lateral deflection of the string will arise that depends on the slip angle size and the history of the lateral deflection of previous points having contact with the road.For calculating the lateral deflection v1 of the string in the first point of contact with the road, the following differential equation is valid during braking slip:with the relaxation length in the lateral direction. The turnslip can be neglected at radii larger than 10 m. This differential equation cannot be used at zero speed, but when multiplying with Vx, the equation can be transformed to:When the tire is rolling, the lateral deflection depends on the lateral slip speed; at standstill, the deflection depends on the relaxation length, which is a measure for the lateral stiffness of the tire. Therefore, with this approach, the tire is responding to a slip speed when rolling and behaving like a spring at standstill. When the UA Tire is used for the force calculations, at positive Vsx (traction) the Vx should be replaced by Vr in these differential equations.A similar approach yields the following for the deflection of the string in longitudinal direction:Now the practical slip quantities, ’ and ’, are defined based on the tire deformation:These practical slip quantities and are used instead of the usual and definitions for steady-state tire behavior. kVlow_x and kVlow_y are the damping rates at low speed applied below the LOW_SPEED_THRESHOLD speed. For the LOW_SPEED_DAMPING parameter in the tire property file yields:kVlow_x= 100 · kVlow_y= LOW_SPEED_DAMPINGNote: If the tire property file's REL_LEN_LON or REL_LEN_LAT = 0, then steady-state tire behavior is calculated as tire response on change of the slip and .Tire Model ParametersSymbol: Name in tire propertyfile: Units*: Description:r1 UNLOADED_RADIUS L Tire unloaded radiuskz VERTICAL_STIFFNESS F/L Vertical stiffnesscz VERTICAL_DAMPING FT/L Vertical dampingCr ROLLING_RESISTANCE L Rolling resistance parameter Cs CSLIP F Longitudinal slip stiffness,C CALPHA F/A Cornering stiffness,C CGAMMA F/ACamber stiffness,UMIN UMIN - Minimum friction coefficient(Sg=1)UMAX UMAX - Maximum friction coefficient(Ssg=0)x REL_LEN_LON L Relaxation length inlongitudinal directiony REL_LEN_LAT L Relaxation length in lateraldirection* L=length, F=force, A=angle, T=timeForce Evaluation in UA-Tire•Normal Force•Slip Ratios•Friction CoefficientNormal ForceThe normal force F z is calculated assuming a linear spring (stiffness: k z ) and damper (damping constant c z ), so the next equation holds:If the tire loses contact with the road, the tire deflection and deflection velocity become zero so the resulting normal force F z will also be zero. For very small positive tire deflections the value of the damping constant is reduced and care is taken to ensure that the normal force Fz will not become negative.In stead of the linear vertical tire stiffness cz , also an arbitrary tire deflection - load curve can be defined in the tire property file in the section[DEFLECTION_LOAD_CURVE], see also the Property File Format Example. If a section called [DEFLECTION_LOAD_CURVE] exists, the load deflection datapoints with a cubic spline for inter- and extrapolation are used for the calculation of the vertical force of the tire. Note that you must specify VERTICAL_STIFFNESS in the tire property file but it does not play any role.Slip RatiosFor the calculation of the slip forces and moments a number of slip ratios will be introduced:Longitudinal Slip Ratio: SsThe absolute value of longitudinal slip ratio, Ss, is defined as:Where k is limited to be within the range -1 to 1.Lateral Slip Ratios: Sa , Sg , SagThe lateral slip ratio due to slip angle, S, is defined as:The lateral slip ratio due to inclination angle, S, is defined as:A combined lateral slip ratio due to slip and inclination angles, S, is defined as:where is the length of the contact patch.Comprehensive Slip Ratio: SsagA comprehensive slip ratio due to longitudinal slip, slip angle, and inclination angle may be defined as:Friction CoefficientThe resultant friction coefficient between the tire tread base and the terrain surfaceis determined as a function of the resultant slip ratio (Ss) and friction parameters (UMAX and UMIN ). The friction parameters are experimentally obtained data representing the kinematic property between the surfaces of tire tread and the terrain.A linear relationship between Ss and , the corresponding road-tire friction coefficient, is assumed. The figure below depicts this relationship.Linear Tire-Terrain Friction ModelThis can be analytically described as:m = UMAX - (UMAX - UMIN) * SsagThe friction circle concept allows for different values of longitudinal and lateralfriction coefficients (x and y) but limits the maximum value for both coefficientsto . See the figure below.Friction Circle ConceptThe relationship that defines the friction circle follows:or andwhere:Slip Forces and MomentsTo compute longitudinal force, lateral force, and self-aligning torque in the SAE coordinate system, you must perform a test to determine the precise operating conditions. The conditions of interest are:•Case 1: 0•Case 2: 0 and C S C S•Case 3: 0 and C S C S•Forces and moments at the contact pointThe lateral force Fh can be decomposed into two components: Fha and Fhg. The twocomponents are in the same direction if a· g < 0 and in opposite direction if 0. Case 1. ag < 0Before computing the longitudinal force, the lateral force, and the self-aligning torque, some slip parameters and a modified lateral friction coefficient should bedetermined. If a slip ratio due to the critical inclination angle is denoted by S c, then it can be evaluated as:If Ssc represents a slip ratio due to the critical (longitudinal) slip ratio, then it can be evaluated as:If a slip ratio due to the critical slip angle is denoted by S c, then it can be determined as:when Ss Ssc.The term critical stands for the maximum value which allows an elastic deformation of a tire during pure slip due to pure slip ratio, slip angle, or inclination angle. Whenever any slip ratio becomes greater than its corresponding critical value, an elastic deformation no longer exists, but instead complete sliding state representsthe contact condition between the tire tread base and the terrain surface.A nondimensional slip ratio Sn is determined as:where:A nondimensional contact patch length is determined as:A modified lateral friction coefficient is evaluated as:where is the available friction as determined by the friction circle.To determine the longitudinal force, the lateral force, and the self-aligning torque, consider two subcases separately. The first case is for the elastic deformation state, while the other is for the complete sliding state without any elastic deformation of a tire. These two subcases are distinguished by slip ratios caused by the critical values of the slip ratio, the slip angle, and the inclination angle. Specifically, if all of slip ratios are smaller than those of their corresponding critical values, then there exists an elastic deformation state, otherwise there exists only completesliding state between the tire tread base and the terrain surface.(i) Elastic Deformation State: S S c, Ss Ssc, and S S cIn the elastic deformation state, the longitudinal force F, the lateral force F, and three components of the self-aligning torque are written as functions of the elastic stiffness and the slip ratio as well as the normal force and the friction coefficients, such as:where:•is the offset between the wheel plane center and the tire treadbase.•is set to zero if it is negative.•the length of the contact patch.Mz is the portion of the self-aligning torque generated by the slip angle . Mzsand Mzs are other components of the self-aligning torque produced by thelongitudinal force, which has an offset between the wheel center plane and the tire tread base, due to the slip angle and the inclination angle , respectively. The self-aligning torque Mz is determined as combinations of Mz, Mzs and Mzs.(ii) Complete Sliding State: S S c, Ss Ssc, and S S cIn the complete sliding state, the longitudinal force, the lateral force, and three components of the self-aligning torque are determined as functions of the normal force and the friction coefficients without any elastic stiffness and slip ratio as:Case 2:0 and C S C SAs in Case 1, a slip ratio due to the critical value of the slip ratio can be obtained as:A slip ratio due to the critical value of the slip angle can be found as:when Ss Ssc.The nondimensional slip ratio Sn, is determined as:where:The nondimensional contact patch length ln is found from the equation ln = 1 - Sn, and the modified lateral friction coefficient is expressed as:For the longitudinal force, the lateral force and the self-aligning torque two subcases should also be considered separately. A slip ratio due to the critical value of the inclination angle is not needed here since the required condition for Case 2,C S C S, replaces the critical condition of the inclination angle.(i) Elastic Deformation State: Ss Ssc and S SacIn the elastic deformation state:(ii) Complete Sliding State: Ss Ssc and S SacCase 3:0 and C S C SSimilar to Cases 1 and 2, slip ratios due to the critical values of the inclination angle and the slip ratio are obtained as:The nondimensional slip ratio Sn, is expressed as:where:For the longitudinal force, the lateral force, and the self-aligning torque, two subcases should also be considered similar to Cases 1 and 2. A slip ratio due to the critical value of the slip angle is not needed here since the required condition forCase 3, C S C S, replaces the critical condition of the slip angle. (i) Elastic Deformation State: S S c and Ss SscIn the elastic deformation state, F and Mz can be written:(ii) Complete Sliding State: S S c and Ss SscIn the complete sliding state, F, F, Mz, Mzs, and Mzs can be determined by using:respectively. The longitudinal force F , the lateral force F, and three componentsof the self-aligning torques, Mz , Mzs , and Mzs , always have positive values, but they can be transformed to have positive or negative values depending on the slip ratio s, the slip angle , and the inclination angle in the SAE coordinate system. Tire Forces and Moments in the SAE Coordinate SystemFor the general formulations of the longitudinal force Fx, lateral force Fy, and self-aligning torque Mz, in the SAE coordinate system, the three possible combinations of the slip ratio, the slip angle, and the inclination angle are also considered. Longitudinal Force:Fx = sin(k) F , for all cases Lateral Force: F y = -sin() F, for cases 1 and 2F y = sin() F , for case 3 Self-aligning Torque:M z = sin() M z - sin() [-sin() M zs + sin()M zs ]Rolling Resistance Moment:My = -Cr Fz, for a forward rolling tire. My = Cr Fz , for a backward rolling tire.Operating Mode: USE_MODEYou can change the behavior of the tire model through the switch USE_MODE in the [MODEL] section of the tire property file.•USE_MODE = 0: Steady-state forces and moments • The tire forces and moments react instantaneously to changes in the tire kinematic states. •USE_MODE = 1: Transient tire behavior • The tire will have a lagged response because of the so-called relaxation length in both longitudinal and lateral direction. See Lagged Longitudinal and Lateral Slip Quantities (transient tire behavior).•The effect of the relaxation lengths will be most pronounced at low forward velocityand/or high excitation frequencies. •USE_MODE = 2: Smoothing of forces and moments on startup of the simulation •When you indicate smoothing by setting the value of use mode in the tire property file, Adams/Tire smooths initial transients in the tire force over the first 0.1seconds of simulation. The longitudinal force, lateral force, and aligning torque are multiplied by a cubic step function of time. (See STEP in the Adams/Solver online help.) Longitudinal Force FLon = S*FLon Lateral Force FLat = S*FLat Aligning Torque Mz = S*MzTire Carcass ShapeYou can optionally supply a tire carcass cross-sectional shape in the tire property file in the [SHAPE] block. The 3D-durability, tire-to-road contact algorithm uses this information when calculating the tire-to-road volume of interference. If you omit the [SHAPE] block from a tire property file, the tire carcass cross-section defaults to the rectangle that the tire radius and width define.You specify the tire carcass shape by entering points in fractions of the tire radius and width. Because Adams/Tire assumes that the tire cross-section is symmetrical about the wheel plane, you only specify points for half the width of the tire. The following apply:•For width, a value of zero (0) lies in the wheel center plane. •For width, a value of one (1) lies in the plane of the side wall. •For radius, a value of one (1) lies on the tread. For example, suppose your tire has a radius of 300 mm and a width of 185 mm and that the tread is joined to the side wall with a fillet of 12.5 mm radius. The tread then begins to curve to meet the side wall at >+/- 80 mm from the wheel center plane. If you define the shape table using six points with four points along the fillet, the resulting table might look like the shape block that is at the end of the property format example (see SHAPE ).Property File Format Example$--------------------------------------------------------MDI_HEADER [MDI_HEADER]FILE_TYPE = 'tir' FILE_VERSION = 2.0 FILE_FORMAT = 'ASCII'(COMMENTS) {comment_string} 'Tire - XXXXXX''Pressure - XXXXXX' 'TestDate - XXXXXX' 'Test tire''New File Format v2.1'$-------------------------------------------------------------units [UNITS] LENGTH= 'meter' FORCE= 'newton'ANGLE= 'rad'MASS= 'kg'TIME= 'sec'$-------------------------------------------------------------model [MODEL]! use mode123! ------------------------------------------! relaxation lengthsX! smoothingX !PROPERTY_FILE_FORMAT= 'UATIRE'USE_MODE= 2$---------------------------------------------------------dimension [DIMENSION]UNLOADED_RADIUS= 0.295WIDTH= 0.195ASPECT_RATIO= 0.55$---------------------------------------------------------parameter [PARAMETER]VERTICAL_STIFFNESS= 190000VERTICAL_DAMPING= 50ROLLING_RESISTANCE= 0.003CSLIP= 80000CALPHA= 60000CGAMMA= 3000UMIN= 0.8UMAX= 1.1REL_LEN_LON= 0.6REL_LEN_LAT= 0.5$-------------------------------------------------------------shape[SHAPE]{radial width}1.0 0.01.0 0.21.0 0.41.0 0.61.0 0.80.9 1.0$---------------------------------------------------------------------load_curve $ For a non-linear tire vertical stiffness (optional)$ Maximum of 100 points[DEFLECTION_LOAD_CURVE]{penfz}0.0000.00.001212.00.002428.00.003648.00.0051100.00.0102300.00.0205000.00.0308100.0。
AdamsCar路面谱模型建立以及整车底盘部件载荷提
Adams/Car路面谱模型建立以及整车底盘部件载荷提取作者：Simwe 来源：MSC发布时间：2014-04-02 【收藏】【打印】复制连接【大中小】我来说两句：(0) 逛逛论坛利用MSC Adams虚拟样机技术，建立准确的路面模型、轮胎模型以及整车动力学模型，模拟试验场各种工况的分析，测量底盘关键部件的载荷谱，可以为改进结构设计的有限元强度、刚度分析提供边界元载荷条件，以及实现车辆开发过中车身与底盘关键零部件的疲劳寿命预测。
MSC Adams虚拟样机技术方法，最终实现在车辆前期设计阶段，根据用户使用工况来确定关键部件疲劳寿命预测的虚拟试验，并利用准确的部件载荷谱，快速做出零部件可靠性的分析判断；降低开发费用，缩短开发周期，使汽车的设计真正符合用户的使用情况，大大提高汽车设计开发水平以及企业核心竞争力。
一、建立2D路面模型Adams中二维路面的接触采用 point-follower 的方法，只用XZ平面上的点定义形成二维曲线，可以建立各种不同的路面类型：汽车主机厂通常会进行整车跨越三角形凸起路面工况，确认车辆行驶跨越突起路面时的前/后悬架系统、转向系统及车身受冲击受力（上下入力）强度的试验，此时就可以用二维路面描述建立路面模型。
各种不同形状的路面，通过在路面文件中定义各数据块参数完成定义，具体不同路面参数，如下图所示：上一页 1 23下一页二、3D等效容积路面建立3D 等效体积模型为三维的轮胎-路面接触模型，用来计算路面和轮胎之间交叉的体积。
路面是用一系列离散的三角形片来表示，而轮胎则用一系列的圆柱表示。
采用此路面模型，你可以模拟车辆在运动过程中碰到路边台阶、凹坑或在粗糙路面或不规则路面上运动的情形。
3D 等效体积路面模型为一般的三维表面，并用一系列的三角形片表示。
右侧的图表示一个由编号为 1 到 6 的六个节点构成的路表面。
六个节点共构成四个三角形的面单元，分别表示为 A、B、 C 和 D。
基于ADAMS的汽车脉冲路面仿真
基于ADAMS的汽车脉冲路面仿真宋年秀; 刘亚光; 张丽霞【期刊名称】《《汽车零部件》》【年(卷),期】2019(000)009【总页数】4页(P1-4)【关键词】脉冲路面; 脉冲输入; 平顺性【作者】宋年秀; 刘亚光; 张丽霞【作者单位】青岛理工大学机械与汽车工程学院山东青岛266033【正文语种】中文【中图分类】U270.20 引言汽车在道路上行驶时难免会遇到诸如减速带、凹坑、凸块等各种不平工况，当汽车通过这些障碍时，轮胎传至驾驶员座椅处的振动加速度会发生较大的波动。
为了将这种行驶工况考虑在内，通常情况下采用长为400 mm的三角形单凸块[1]。
根据试验条件不同，脉冲输入可用相应高度的凸块或减速带，而并未对为何使用三角形凸块或是减速带进行阐述。
针对国家标准GB/T 4970-2009[2]所提出的对路面脉冲激励的评价方法进行仿真分析。
首先基于ADAMS/Car，利用某普及型轿车的相关参数，建立包括悬架、车身、轮胎、转向系统在内的整车系统，对各车速下的包括：矩形凸块、斜角凸块、凹坑、减速带在内的6种脉冲输入进行平顺性仿真，并对仿真结果进行分析比较，得到更适宜作为脉冲输入的脉冲轮廓类型。
最后，在脉冲路面的仿真过程中，将随机路面考虑在内，使平顺性仿真更加符合实际工况。
1 整车模型的建立通过对该轿车的测量以及对其相关参数进行查询，得到了整车的主要参数，如表1所示。
在ADAMS/Car中，根据得到的相关参数建立各个子系统的模型，最后将其组装成整车模型并进行平顺性分析。
本文作者选用轿车的前后悬架分别为双横臂独立悬架以及多连杆悬架，对其进行建模得到如图1和图2所示的悬架模型，最终对各子系统进行装配得到如图3所示的轿车整车模型。
表1 整车主要参数参数数值整车整备质量/kg1 360底盘质心高度/mm560质心距前轴距/mm1 125质心距后轴距/mm1 450车身绕横轴转动惯量/(kg·mm2)6.2×108车身绕纵轴转动惯量/(kg·mm2)2.0×108前悬架垂直刚度/(N·mm-1)31前悬架阻尼系数/(N·s·mm-1)2.8后悬架垂直刚度/(N·mm-1)26后悬架阻尼系数/(N·s·mm-1)2.5前轮距/mm1 432后轮距/mm1 220前后轴距/mm2 631轮胎规格225/55R17图1 双横臂独立悬架图2 多连杆悬架图3 整车模型2 脉冲输入仿真2.1 脉冲输入的建立利用ADAMS/Car对汽车通过脉冲路面的振动进行分析时，可以使用插件Road Builder对脉冲路面进行3D建模，也可以使用后缀名为.rdf的TeimOrbit格式路面文件进行2D或3D路面的创建。
汽车平顺性仿真中路面文件生成方法
汽车平顺性仿真中路面文件生成方法
于景飞
【期刊名称】《交通科技与经济》
【年(卷),期】2010(012)006
【摘要】在ADAMS/View中进行汽车平顺性仿真,需要根据不同的实验方法建立相应的路面文件,构造满足仿真要求的路面是该任务的一大难点.探讨在ADAMS仿真中生成各种路面文件的一些方法,生成常用车速下的路面文件,结合整车模型,对生成路面进行验证,仿真结果表明生成方法的可行性及生成路面的正确性.
【总页数】3页(P107-109)
【作者】于景飞
【作者单位】内蒙古科技大学建筑与土木工程学院,内蒙古包头014010
【正文语种】中文
【中图分类】U46
【相关文献】
1.基于ADAMS／Car微型观光电动汽车典型路面平顺性仿真 [J], 乔长胜;李耀刚;琚立颖;冯泽;张文明;
2.碎石路面上汽车平顺性仿真分析 [J], 袁绍华;王昆;王曙光;黄波
3.路面减速带对汽车平顺性和安全性影响的仿真与试验研究 [J], 任成龙;徐慧宝
4.随机路面输入对汽车平顺性的仿真分析 [J], 熊金胜;王天利;张健;章桂林
5.基于虚拟路面的汽车平顺性仿真分析 [J], 刘彪;叶昊;段敏;陈志强;沈澳;郑福民
因版权原因，仅展示原文概要，查看原文内容请购买。
路面文件的生成
第3章路面文件的生成3.1 随机路面不平度的拟合理论[4][5][17][18][39]大量的测量分析结果表明，路面不平度具有随机、平稳和各态历经的特性，可以用平稳随机过程理论来分析描述。
通常把道路垂直纵断面与道路表面的交线作为路面不平度的样本，通过样本的数学特征――方差或功率谱密度函数来描述路面。
均值为零时，方差可以反映路面不平度大小的总体情况；功率谱密度函数能够表示路面不平度能量在空间频域的分布，它说明了路面不平度或者说路面波的结构。
当功率谱密度用坐标图表示时，坐标上功率谱密度曲线下的面积就是路面不平度方差。
从功率谱密度函数不仅能了解路面不平度的结构，还能反映出路面的总体特征。
因此，功率谱密度函数（PSD）是路面不平度的最重要数学特征。
文献[17、39]介绍了采用多种方法生成路面不平度的时域模型，如：滤波白噪声生成法（线性滤波法），基于有理函数PSD模型的离散时间随机序列生成法，根据随机信号的分解性质所推演的谐波叠加法（也称频谱表示法），以及基于幂函数功率谱的快速Fourier反变换生成法等。
白噪声激励模拟的基本思想是：将路面高程的随机波动抽象为满足一定条件的白噪声, 然后经一假定系统进行适当变换而拟合出路面随机不平度的时域模型。
离散时间随机序列生成法的基本思想是：基于Parkhilovsk ii 提出的另一种有理函数形式的功率谱密度表达式[17]，建立路面不平度时间离散化模拟的递推公式[17]。
谐波叠加法的基本思想是：随机正弦波（或其他谐波）叠加法采用以离散谱逼近目标随机过程的模型, 是另一种离散化数值模拟路面的方法。
基于幂函数功率谱的快速Fourier反变换生成法的基本思想是：由功率谱密度的离散采样构造出频谱, 然后对频谱进行Fourier逆变换得到时域模拟的轨道不平顺激励函数。
但是，不管是标准道路谱还是实测道路谱，其PSD 是路面不平度的一个统计量。
因此，对应于测量范围内某一种确定的路面不平度，其PSD 是唯一的；但对于给定的PSD ，其模拟设计的路面不平度并不唯一，也就是说频域模型和时域模型并非一对一的映射，因此从频域模型所得的路面不平度的时域模型只能看成是满足给定路谱的全部可能的路面不平度中的一个样本函数。
5程车辆ADAMS随机路面激励时域模型的建立
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１，轮距相关 车辆在实际环境中所遇到的路面 输八可以简化为轮距相关、轴距滞后 模型。显然，这种模型只适合于车辆 转弯半径很大的情况，最好是车辆直 线行驶工况。双辙路面随机输入包含
两个随机过程，平动随机过程％和转 动随机过程屯，如图１所示，并且认为 双辙路面输入为白噪声经过一阶滤波 后所生威的。
描述车辆在普通路面上行驶时所遇到 的路面输入；而确定性输入则用来描 述车辆所遏到的坑、包等激励。随机
路面输入ｚ，可以用一阶滤波白噪声来 描述。
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其中夕是路面不平度系数，材是 车辆前进速度，ｗ是高斯分布白噪 声。路面等级对应的空间频率估计值 如表所示。
表路面等级与空闻频率估计值
路面等级
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ADAMS-Car路面生成技术总结
如果仅以基本行驶模型分析为目的，通常不考虑断点的影响，采用单斜率路面输入谱基本上就 可满足要求。假设不平度系数 G0 按下表取值，则斜率 p 通常取 2~2.5 为宜。
各种典型路面的不平度系数 G0 值 单位：m3/cycle 路面类型 高速公路 主干道 支路 范围 3×10-8~5×10-7 3×10-8~8×10-6 5×10-7~3×10-5 均值 1×10-7 5×10-7 5×10-6
w
G( j)
Zg
随机滤波白噪声表达的路面功率谱密度为：
S ( f ) G0
u 2 G( f ) 2 2 f
Z g G ( j ) w
式中， 2 为随机白噪声 w 的方差，取值为 1； Z g 为路面不平度位移。 若以圆周率 （单位为 rad/s）表示，上式则要改为：
S ( )
式中， nd 为双对数坐标下谱密度曲线断点处的空间频率。 实际上，上式仍有与实际情况不符之处，比如在空间频率趋向零时，所表达的路面输入振幅将 趋向无穷大，而实际路面并非如此，从实测的路面谱中也可看出，路面谱密度 S 的值在低频段趋向 平坦。基于这点考虑，可引入一个下截止频率 n0 ，即当频率低于 n0 时，谱密度幅值保持恒定。在极
倍频带 1/3 倍频带 1/12 倍频带 从最低频带（零频率除外）到中心频率 0.0312m-1 从倍频带的末尾值到中心频率 0.25-1 从 0.2726m-1 到最高计算频率
在规定的带宽内对功率谱密度进行平均计算，其光滑计算公式为：
nH 1
[(n 0.5) Be nl (i )]S (nL ) S (i ) L nh (i) nl (i )
由此可得到：
2 S （f ） 2 G0u 2 G ( ) 2 2 2
ADAMS路面
时域道路模型在MSC.ADAMS中道路时域道路模型是通过属性文件来表达的，而属性文件的创建是使用独立插件Road Builder来完成，通过Road Builder还可以创建IPG和ARM格式包括路肩的3D 道路。
它支持以下种类的路面几何轨迹✧常规仿真车道（开环或闭环）✧赛车道（Chicane）✧椭圆环车道（Oval）✧路标筒车道通过Road Builder可以生成下列种类的文件：✧.rdf✧.drd✧.dcd✧.shl✧.dig （仅用于IPG）✧.road （仅用于IPG）注：使用Road Builder需要单独的许可证文件（license file），但在ADAMS 2005R2版里已经作为标准插件。
在ADAMS里路面模型是通过后缀名为.rdf的路面文件引入到仿真环境中，路面文件的结构仍然是TeimOrbit格式的ASCII文本文件。
例如在操纵性仿真中常用的平整路面文件有：在路面文件中的标题数据块、单位数据块的定义方式与DCF、DCD文件一样，[MODEL]数据块定义路面的类型，[GRAPHICS]数据块定义路面几何图形，注意，在2D道路中只有平整路面Flat才有路面图形；其他类型的路面可以通过专用软件包FTire-tools提供的road visualization功能观察路面形状（另一种方法是用函数构造器下的create_shell_from_rdf函数将路面文件转化为shell文件，再将shell壳文件加入到模型中）；[PARAMETERS]数据块定义路面的如摩擦系数、几何形态等参数。
道路类型：道路的类型在TeimOrbit格式的道路属性文件中通过[MODEL]数据块中的METHOD、ROAD_TYPE语句定义，[MODEL]数据块定义的常用道路类型如下：[FUNCTION_NAME]函数名称变量指路面与轮胎接触函数ID 号2D 道路文件MTTHOD ＝2D 时二维路面的参数[PARAMETERS]子数据块：参数子数据块[PARAMETERS]的结构根据路面类型的不同而不同，基本上可以划分为3隔部分：通用参数段、路型参数段和数据组，用符号$分开。
标准路面激励下的车轮动态负载分析
标准路面激励下的车轮动态负载分析李能; 刘春光; 燕玉林【期刊名称】《《机械设计与制造》》【年(卷),期】2019(000)008【总页数】4页(P41-44)【关键词】ADAMS; 动力学; 随机路面; 动态负载【作者】李能; 刘春光; 燕玉林【作者单位】装甲兵工程学院控制工程系北京 100072【正文语种】中文【中图分类】TH16; TJ8111 引言车辆匀速驶过平直路面会产生恒定轮胎力，由于实际道路表面形状不规则，导致轮胎受力波动，产生连续变化负载[1]。
动态负载易造成轮轴疲劳损伤，同时影响轮毂电机寿命。
因此，研究确定车轮动态负载对电机选择和车辆结构优化有重要意义。
当前有关动态负载研究，大多针对车辆部件疲劳损伤的载荷谱[2-3]。
载荷谱属于统计数据，不能实时反映车辆位置与车轮负载的关系。
道路重构技术大多采用MATLAB软件编程，过程繁琐，程序复杂。
基于ADAMS软件搭建整车动力学模型[4]，构建等级路面，研究直驶工况下不同路面与车速对车轮动态负载的影响。
2 车—路系统动力学模型2.1 整车模型搭建研究对象是包含多个精细结构的复杂系统，为简化模型只对车轮负载产生主要影响的部件建模，主要包括车身、悬架、双桥转向系统、轮胎模型。
车辆的主要技术参数，如表1所示。
车辆坐标系定义，如图1（a）所示。
X轴—车辆前进的方向，向后为正；Y轴—车身的侧向方向，指向车身右侧为正；Z轴—垂直于地面的方向，向上为正，Z轴的负方向—重力加速度的方向。
表1 整车基本性能参数Tab.1 Basic Performance Parameters项目数值车长（mm） 7 873车宽（mm） 2 936车高（至顶甲板/炮塔顶端）（mm） 2125/2 688一桥轮距（mm） 2 600二桥轮距（mm） 2 600三桥轮距（mm） 2 600四桥轮距（mm） 2 600轮胎半径（mm） 615整车质量（kg） 23 000图1 车-路系统动力学模型Fig.1 Dynamics Model of Vehicle-Road System车身是根据实车质量和转动惯量构建3D刚体模型。
Matlab实现ADAMS三维随机路面建模
Matlab实现ADAMS三维随机路面建模黄志强;郑旺辉【摘要】根据谐波叠加法得到二维随机路面谱,通过改进的谐波叠加法将二维路面谱扩展到三维,形成三维随机路面谱的建模方法.详解了ADAMS中三维随机路面文件的编制规则,通过Matlab编程计算出路面文件中的路面点高程值阵列,生成ADAMS三维随机路面模型文件,仿真计算过程表明路面可用于仿真计算研究.【期刊名称】《现代防御技术》【年(卷),期】2018(046)003【总页数】6页(P165-170)【关键词】谐波叠加法;路面谱;三维路面;仿真;建模;模型文件【作者】黄志强;郑旺辉【作者单位】北京机械设备研究所,北京100854;北京机械设备研究所,北京100854【正文语种】中文【中图分类】TJ812;N945.120 引言随机路面中激励点的高程值变化可以用另一个词汇来表达：路面不平度。
路面不平度[1]定义为道路表面相对于理想平面的偏离，它描述了随机路面下车辆的振动输入。
同时，相较于车辆发动机等激励源，路面不平度是车辆振动系统的主要振源，在建立车辆系统整车数学或者仿真模型进行平顺性分析时，可以忽略发动机等激励源，而将路面不平度激励作为唯一的激励源施加在车上。
路面不平度通常用来描述路面的起伏程度[1]。
对路面谱的研究首先在于获取路面谱，最直接的方法就是测量，为此，研究者们发明了多种路面谱测量设备。
近年来，随着传感器技术、计算机技术和信号处理技术的飞速发展, 人们对路面不平度的采集、测量和各种试验方法也在不断的更新和改进[1],这一领域已经涌现出了多种测量和试验分析的新方法。
一般按照测量原理的不同可分为直接接触式测量仪和非接触式测量仪(响应式测量仪)等。
国内直接接触式测量仪的典型代表是1979年, 国内长春汽车研究所的赵继海等人发明的拖车式真实路形仪[1], 通过测量拖车上前后轮与拖臂等部件之间的角度变化来获得路面的真实路形。
在对一定道路的测量和分析研究中，学者们发现路面不平度虽然不能够用普通数学函数描述，但是其具有随机、平稳、各态历经的特征[1],这些特征在统计学意义上具有完整的理论描述方法，研究发现路面不平度可以用平稳随机过程理论来分析描述。
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时域道路模型
在MSC.ADAMS中道路时域道路模型是通过属性文件来表达的，而属性文件的创建是使用独立插件Road Builder来完成，通过Road Builder还可以创建IPG和ARM格式包括路肩的3D道路。
它支持以下种类的路面几何轨迹
✧常规仿真车道（开环或闭环）
✧赛车道（Chicane）
✧椭圆环车道（Oval）
✧路标筒车道
通过Road Builder可以生成下列种类的文件：
✧.rdf
✧.drd
✧.dcd
✧.shl
✧.dig （仅用于IPG）
✧.road （仅用于IPG）
注：使用Road Builder需要单独的许可证文件（license file），但在ADAMS 2005R2版里已经作
为标准插件。
在ADAMS里路面模型是通过后缀名为.rdf的路面文件引入到仿真环境中，路面文件的结构仍然是T eimOrbit格式的ASCII文本文件。
例如在操纵性仿真中常用的平整路面文件有：在路面文件中的标题数据块、单位数据块的定义方式与DCF、DCD文件一样，[MODEL]数据
块定义路面的类型，[GRAPHICS]数据块定义路面几何图形，注意，在2D道路中只有平整路面Flat才有路面图形；其他类型的路面可以通过专用软件包FTire-tools提供的road visualization 功能观察路面形状（另一种方法是用函数构造器下的create_shell_from_rdf函数将路面文件转化为shell文件，再将shell壳文件加入到模型中）；[PARAMETERS]数据块定义路面的如摩擦系
数、几何形态等参数。
道路类型：
道路的类型在T eimOrbit格式的道路属性文件中通过[MODEL]数据块中的METHOD、ROAD_TYPE语句定义，[MODEL]数据块定义的常用道路类型如下：
METHOD FUNCTION_NAME ROAD_TYPE
‘2D’
二维路面‘ARC901’DRUM 轮胎转鼓试验台
FLAT 平整路面
PLANK 矩形凸块路
POLY_LINE 折线路面
POT_HOLE 凹坑路面
[FUNCTION_NAME]
函数名称变量指路面与轮胎接触函数ID号
2D道路文件
MTTHOD＝2D时二维路面的参数[PARAMETERS]子数据块：
参数子数据块[PARAMETERS]的结构根据路面类型的不同而不同，基本上可以划分为3隔部分：通用参数段、路型参数段和数据组，用符号$分开。
路型参数段：
ROAD_TYPE ＝FLAT
——平整路面
ROAD_TYPE ＝DRUM
——转鼓试验台
参数子数据块
镶条参数示意图
参数说明
DIAMETER 转鼓直径，通常大于4m；当转鼓的直径为负数时，试验使用的
是转鼓外表面，为正数时使用转鼓的内表面。
与此对应，一个
正的转鼓速度在外表面时为逆时针，在内表面时为顺时针。
ROTATION_ANGLE_XY_PLANE 转鼓轴线与XY平面角度
V转鼓表面线速度，（应确认汽车本身的速度是为0的，并且转鼓
的中心与汽车的x＝0共线）。
NUMBER_CLEATS镶条数目（镶条数目可以为0，即使用光滑表面的试验鼓）CLEAT_HEIGHT镶条高度
CLEAT_STARTING_ANGLE第一个镶条在鼓面上的角度位置
CLEAT_LENGTH镶条底边宽度
CLEAT_BEVEL_EDGE_LENGTH镶条45°倒角边长
ACCELERATION_TIME任选的仿真开始时刻，在这段时间内转鼓加速到额定速度(XZR_DATA)
共享数据库中mdi_2d_ramp.rdf不是T eimOrbit格式，不能用于A/Car模块的标准仿真。
它
的功能可以用ROAD_TYPE＝plank代替
ROAD_TYPE = plank
——凸块路面
参数子数据块
参数
说明
HEIGHT 凸块高度
START 汽车初始位置到凸块的距离 LENGTH
凸块沿X 轴方向长度
BEVEL_ENGE_LENGTH 凸块的倒角底边长度，倒角规定为45°；如果该长度值为负数，则表示该倒角为圆角，圆角的半径为该值的绝对值。
DIRECTION
凸块方向角（°），以与Y 轴的夹角表示；如果DIRECTION ＝0，表示横放在汽车的行进方向（设定汽车沿-X 轴方向前进）
ROAD_TYPE = poly_line —— 折线路面
参数子数据块
[PARAMETERS]必须有(XZ_DATA) 子段；在XZ 子段中的3列数据，其意义是：第一列为X 值（行程值）；第二列和第三列分别是左右车轮轨迹处的Z 向高度。
(XZ_DATA ) 子段可以定义得很长（超过200行），且不需要任何注释行，注意折线路面同时定义了两侧的轮辙。
ROAD_TYPE = pot_hole —— 凹坑路面
参数子数据块
HEIGHT
LENGTH
START
Z
X
ROAD_TYPE = ramp ——斜角凸块路面
参数子数据块
ROAD_TYPE = roof ——三角形凸块路面
参数子数据块
ROAD_TYPE = sine ——正弦波路面
参数子数据块
ROAD_TYPE = sine_sweep ——正弦变波纹路面
参数子数据块
Height
Start
Height
Length
Start
Length
Depth
Start
α
Slope=tan(α)
Start Wave length
Amplitude
参数 说明
START
波纹路开始时的车辆行程 END 波纹路结束时的车辆行程 AMPLITUDE_AT_START 开始时波幅 AMPLITUDE_AT_END 结束时波幅 WAVE_LENGTH_AT_START 开始时波长
WAVE_LENGTH_AT_END
结束时波长，必须≤开始时波长 SWEEP_TYPE sweep_type = 0：频率在全程波纹路段内线性递增
sweep_type= 1：频率在全程波纹路段按自然内对数递增
ROAD_TYPE = stochastic_uneven —— 随机不平路面
在ADAMS 中的二维随机路面是根据路面文件按白噪声线性滤波法生成的左右两条轮辙纵剖面曲线。
值得注意的是，在2003版（包括2003版）以前，MSC 向用户提供的位于共享数据库中的随机不平路面示例文件mdi_2d_uneven.rdf 是随第一个F-Tire 一起发布的，一直没有得到更新，如果用户要使用该文件作为模板则应修改PATH_CONSTANT 的值为1000m （原为20）。
参数子数据块
参数 说明
START 随机不平路开始时的车辆行程
INTENSITY
按道路级别从ISO 8608选择空间功率谱密度的平均值计算其平方根，即
MeanValue INTENSITY =。
例如，我们选择的随机不平道路的级别是
B ， 则Mean Value ＝4×10-6，002.01046=⨯=-INTENSITY
这个值相当于H 级道路。