外文翻譯--六-輪式車輛期望橫擺角速度和側(cè)偏轉(zhuǎn)向控制方法（原文）

1、International Journal of Automotive Technology, Vol. 9, No. 2, pp. 173?181 (2008) DOI 10.1007/s12239?008?0022?9Copyright © 2008 KSAE 1229?9138/2008/039?07173DESIRED YAW RATE AND STEERING CONTROL METHOD DURING CORNE

2、RING FOR A SIX-WHEELED VEHICLES.-J. AN1)*, K. YI1), G. JUNG2), K. I. LEE1) and Y.-W. KIM3)1)School of Mechanical and Aerospace Engineering, Seoul National University, Seoul 151-744, Korea 2)Department of Computer Aided M

3、echanical Design Engineering, Daejin University, Gyoenggi 487-711, Korea 3)Agency for Defense Development 5-3-3 Group, Daejeon 305-600, Korea(Received 12 June 2007; Revised 21 November 2007)ABSTRACT?This paper proposes a

4、 steering control method based on optimal control theory to improve the maneuverability of a six-wheeled vehicle during cornering. The six-wheeled vehicle is believed to have better performance than a four-wheeled vehicl

5、e in terms of its capability for crossing obstacles, off-road maneuvering and fail-safe handling when one or two of the tires are punctured. Although many methods to improve the four-wheeled vehicle’ s lateral stability

6、have been studied and developed, there have only been a few studies on the six-wheeled vehicle’ s lateral stability. Some studies of the six-wheeled vehicle have been reported recently, but they are related to the desire

7、d yaw rate of a four-wheeled vehicle to control the six- wheeled vehicle’ s maneuvering during corning. In this paper, the sideslip angle and yaw rate are controlled to improve the maneuverability during cornering by ind

8、ependent control of the steering angles of the six wheels. The desired yaw rate that is suitable for a six-wheeled vehicle is proposed as a control target. In addition, a scaled-down vehicle with six drive motors and six

9、 steering motors that can be controlled independently is designed. The performance of the proposed control methods is verified using a full model vehicle simulation and scaled-down vehicle experiment.KEY WORDS : Six-whee

10、led vehicle, Lateral stability, Desired yaw rate, Scaled-down vehicle1. INTRODUCTIONAn independent 6WD (wheel drive)/6WS (wheel steer) mechanism is adopted in a special purposed, military armored vehicle to enhance its s

11、teering performance and its drive capability as an off-road. The six-wheeled vehicle is believed to have better performance than a four-wheeled vehicle in terms of its capability of crossing obstacles, off- road maneuver

12、ing and fail-safe handling when one or two of their tires are punctured. In order for a six-wheeled vehicle to achieve the best maneuverability during corner- ing, the middle and rear wheel steering angles need to be con

13、trolled according to the steering angle of the front wheels and velocity of the six-wheeled vehicle. Many methods have been studied and actively develop- ed to improve a four-wheeled vehicle’ s lateral stability activel

14、y (Zanten et al., 1998; Nagai et al., 1999; Nagai et al., 2002; Shino et al., 2001; Shibahata et al., 1992, Song et al., 2007). However, there have only been a few studies on the lateral stability of a six-wheeled vehicl

15、e. Huh et al. (2000) set the middle wheel steering angle to half of the front wheel steering angle and controlled the rear wheel steering angle to minimize the sideslip angle of their six- wheeled vehicle. Jackson and Cr

16、olla (2002) proposed the yaw rate control method using the direct yaw momentcontrol (DYC) to improve the stability of their six-wheeled vehicle during cornering. Chen et al. (2006) controlled the middle and rear wheel st

17、eering angle using the LQR (linear quadratic regulator) technique with integral control. An et al. (2006) controlled the front, middle and rear wheel steering angle using the LQR technique based on the front wheel steeri

18、ng angle and velocity. However, they used the desired yaw rate of a four-wheeled vehicle to control the six-wheeled vehicle’ s maneuvering during cornering. The middle wheel’ s effect to influence the control target was

19、not considered in this study. In this paper, the sideslip angle and yaw rate are controll- ed to improve the maneuverability during cornering by independent control of the steering angles of six wheels. The desired yaw r

20、ate that is suitable for a six-wheeled vehicle is proposed as a control target. In addition, a scaled- down vehicle is designed and used to evaluate the proposed control method. The scaled-down vehicle has six drive moto

21、rs and six steering motors that can be controlled independently. The scaled-down vehicle is equipped with a micro controller for vehicle motion control and two optical mice that make it possible to measure vehicle veloci

22、ty and yaw rate. The performance of the proposed control methods is verified using full model vehicle simulation results and scaled-down vehicle experimental result. *Corresponding author. e-mail: sjan75@snu.ac.krDESIRE

23、D YAW RATE AND STEERING CONTROL METHOD DURING CORNERING 1753.2. Desired Model (Tomas, 1992) In recent studies of a six-wheeled vehicle, the desired yaw rate was derived from the steady-state cornering equations under the

24、 condition that the middle wheel steering angle is zero, as demonstrated in Figure 3. The middle wheel effect was not considered. In this paper, a new desired model that is suitable for a six- wheeled vehicle is proposed

25、 In low-speed turning, the tire need not develop a lateral force. Thus they roll with no slip angle, as demonstrated in Figure 4. For proper geometry in the turn (assuming small angles), the front wheel steering angle is

26、 defined as the Ackerman angle:(5)The relationship between the front wheel steering angle and the middle wheel steering angle is defined as follows:(6)In high-speed cornering, a lateral acceleration is present. To counte

27、ract the lateral acceleration, the tires must gene- rate a lateral force. As a result, slip angles are presented at each wheel as shown in Figure 5. The steady-state cornering equations are derived from the application o

28、f Newton’ s Second Law along with the equation describing the geometry in turn, as demonstrated in Figure 5. In high-speed cornering, the center of turn ‘ A’ (center of turn at low-speed) is changed to the center of turn

29、 ‘ B’because of the tire slip angles. Each tire side slip angle is defined as follows:(7a)(7b)(7c)To derive the desired model according to the front wheel steering angle and longitudinal velocity in high-speed cornering

30、, the middle wheel steering angle is defined as in Equations (6). By assigning Equations (6) and ?r=0 to Equations (4), Equations (4) is rearranged as follows:(8)The relationship between the front wheel steering angle an

31、d the steady-state yaw rate gain (rss) is defined asB=2Cf mvx - - - - - - - - - 2Cm mvx - - - - - - - - - 2Cr mvx - - - - - - - - -2lf Cf Iz - - - - - - - - - - - - 2lmCm Iz - - - - - - - - - - - - - - 2lrCr Iz - - - - -

32、 - - - - - - -?f =L ? - - -?m=lm lr + ? - - - - - - - - - - - - -=L lf – lm + ? - - - - - - - - - - - - - - - - - - - - - -?m=?f ? lf lm – ? ? ? - - - - - - - - - - - - - - - - - r=Vx ? - - - - -, 1 ? - - -= r Vx - - - -

33、 - ?=?f ? r Vx - - - - - ? ? ? ? lf lm – ? ?=?f lm+lr L - - - - - - - - - - - ? ? ? ??f =?f ??vx lfr + vx - - - - - - - - - - - - - - - - - - -?m =?m ??vx lmr + vx - - - - - - - - - - - - - - - - - - - - -?r =?r ??vx lrr

34、 + vx - - - - - - - - - - - - - - - - - - - -? ·r · = a11 a12 a21 a22?r + b11 b21 ?f + b12 b22 ?m= a11 a12 a21 a22?r + b11 b21 ?f + b12 b22 ?f lm lr + L - - - - - - - - - - - - - ? ? ? ?= a11 a12 a21 a22?r + b1