外文翻譯--在adams中防抱死制動系統(tǒng)的仿真建模（英文）

1、140 ANTI-LOCK BRAKING SYSTEM SIMULATION AND MODELLING IN ADAMS B. Ozdalyan, M. V. Blundell Centre for Automotive Engineering Research and Technology School of Engineering, Coventry University, Coventry CVlSFB, England

2、 Abstract This paper presents the application of the ADAMS (Automatic Dnamic Analysis of Mechanical &stems) computer programmes to model and simulate the performance of an anti-lock braking system (ABS). A study

3、 has been conducted based on a single wheel model and dynamic simulations have been carried out which combine a braking algorithm representing the ABS. The braking models described here embody (FIALA) tyre model base

4、d on tyre tests carried out within the School of Engineering at Coventry University. These tests were conducted to explore the relationship between tyre braking force and wheel slip. Whilst braking torque is applied t

5、o the wheel, slip increases until the wheel is locked and slipping occurs. The simulation results represented here demonstrate how a simple ABS algorithm can be transformed into a vehicle braking model to prevent whe

6、el locking, when severe braking occurs. One of the main objectives of this paper is to investigate the complicated interaction between the tyre and the ABS system. So designers can use this model to decide which tyre

7、s are more suitable with an ABS system. This is demonstrated by comparing the ABS algorithm with models using data for two different tyres and also investigating the influence of changing road conditions from dry to

8、wet to ice. The paper concludes with a discussion of the practical difficulties involved in developing realistic algorithms to represent ABS in computer simulation. Key Words ABS, ADAMS, Automotive, Braking, Modelling

9、 1.0 Introduction The ADAMS software [I] is used to study the behaviour of systems consisting of rigid or flexible parts undergoing large displacement motions. The main usage of ADAMS is within the automotive industry

10、 where the software is commonly used to study suspensions or to study the ride and handling performance of full vehicle models [2-41. This paper describes the use of the software to investigate the performance of an

11、anti-lock braking algorithm on a single wheel model. The experimental data used in this model was obtained from tests performed by Coventry University and is based on the front suspension system of a Peugeot 605. The

12、 suspension system measurements were used to verify the development of the ADAMS model. An initial simplified ABS algorithm has been developed based on the work described in [5]. 2.0 Modelling A quarter vehicle was mo

13、delled using a single wheel, the suspension unit and a body representing the quarter vehicle mass. A schematic of the quarter vehicle model is shown in Figure 1. The suspension is modelled as a series of rigid links

14、connected by joints and rubber bushes. The force characteristics of the spring, the damper and the bump stop bush are also included. The suspension system is connected to a quarter model of the vehicle body, which ha

15、s longitudinal and vertical degrees of freedom so that vehicle can freely move on the X and Z direction via to translational joints, but does not include pitch. \ill I Figure 1. Quarter suspension model. A vertical fo

16、rce acts on the body to represent the effects of weight transfer during the acceleration and a longitudinal force compensates for the lack of rear suspension in this model. These two forces were applied International

17、Conference on SIMULATIOfl 30 September - 2 October 1998, Conference Publication No.457, 0 IEE, 1998 I42 In ADAMS input deck, slip ratio can be defined with the following variable function expression: VAWid, FU = ( Vx(1

18、,J) - Wz(I,J,RM)*R ) / ( Vx(1,J) ) Vehicle velocity (Vx) in X direction between I marker relative to the J marker. Wheel angular velocity (Wz) about Z-axis between I marker to the J marker and it is considered from th

19、e reference marker. Tyre rolling radius (R) can be calculated roughly from the circumference of the loaded tyre. 2.1 Control Algorithms Two simple algorithms were used for the initial modelling of the ABS control, Ari

20、thmetic IF and Step function. Arithmetic IF was used for initially applying the ABS pressure and Step function was controlled on the ABS cycling. This was related to the slip ratio. The initial pressure rise is at a

21、greater rate than the rates used for the ABS control. Therefore ABS starts the cycle mode when the slip ratio limit was passed. The logic of ABS control is shown in Figure 5. Figure 5. Logic of ABS Control Algorithm T

22、he ADAMS DIFF statement was used to determine the pressure in this model. This pressure was used to calculate the braking force and torque on the wheel. 2.1.1 Arithmetic IF and STEP functions Applying initial pressure

23、 in ADAMS can be calculated with following DIFF statement. DIFF/l, IC=0, FUNCTION=IF(VX(I,J): 0, 0, STEP(TIME,0.5,0,0.6,DI)) IC= 0 means value of function is zero when the time is zero. FU=IF(VX(I,J): 0, 0, checks veh

24、icle velocity and accepts to zero if it is stopped or going backward, but if vehicle has velocity then, it is doing the following step function. STEP(TIME,0.5,0,0.6,DI)) states that the rate of pressure change is inc

25、reased to the value of driver input (DI) between time 0.5 to 0.6 second. During this time period it is necessary for ADAMS to continue this simulation gradually. Cycling pressure change can be controlled by another D

26、 I F Fstatement described as follows: DIFF/2,IC=O,,FU=IF(TIME- 1.22:0,0, IF(VARVAL(id)-0.23:ABSon,ABSon, , STEP(VARVAL( id) ,O. 23 ,ABS on,0.25 ,AB S off))) The IF(T1ME-1.22 . . .) part of the statement delay

27、s the ABS cycling time. This allows passing the slip ratio for the first time. 1.22 second determined by experiment due to initial pressure rise. VARVAL(id) calculates the value of the slip ratio and the function sta

28、tes that if slip ratio is less or equal to 0.23 then the pressure is increased by ABS or if the slip is greater then 0.23 the function continues with the step function. The step function switches the ABS cycling from

29、 on to off if the slip ratio is greater than 0.25. Again the differences between these two slip ratios is necessary for ADAMS to count this gradually, because ADAMS has difficulty with sudden changes. When the initial

30、 pressure and cycling pressure is calculated with the above two DIFF statements, the actual value of pressure is returned to the ADAMS with following variable statement: VARIABLEhd, FUNCTION=DIF( 1) + DIF(2) Braking t

31、orque can be applied using the above VARIBALE. This will give the total ABS braking pressure to allow us to calculate the braking torque. 2.1.2 Calculation of Braking Torque There are two changeable variables in the c