外文翻譯--在各種嚴(yán)重路況下frid電動汽車的電氣和機(jī)械聯(lián)合制動（英文）

1、Electric and Mechanical Brake Cooperative Control Method for FRID EVs under Various Severe Road Conditions Nobuyoshi Mutoh*, Hiroyuki Akashi Graduate School, Tokyo Metropolitan University *nmutoh@sd.tmu.ac.jp Abstr

2、act- This paper describes an electric and mechanical brake cooperative control method suitable for front and rear wheel independent drive type electric vehicles (FRID EVs) for various severe road conditions with low f

3、riction coefficient (?) like icy roads and split-? roads. The brake cooperative control method is proposed based on the analysis results of vehicle behavior at the time of braking on split-? roads which is the most da

4、ngerous operation. In the proposed control method, brake force is controlled so as to suppress the imbalanced torque of lateral force occurring between left and right wheels other than the lateral force required fo

5、r revolution. This control is done considering the big difference in the response speed between the electrical and mechanical brakes. Here, it is confirmed through simulations and experiments that stable brake perform

6、ance is obtained with the proposed brake cooperative control method which properly uses a mechanical brake and electrical brake according to the slip ratio value under various severe road environments. INTRODUCTION

7、 Now, in order to effectively deal with the two issues of the environment and energy conservation, usage of electric vehicles (EVs) is being widely studied not only as a means of transport but also as a micro-grid [1]

8、, [2]. In order to promote EVs as vehicles, they must offer compatibility between safety and good running performance, as well as have good economical efficiency. Current EVs have been mainly developed, putting emph

9、asis on economical efficiency. Based on the fail-safe concept, fault tolerant control [3]-[6] has been studied that allows EVs to continue running with a degraded function after failure. However, from the viewpoint of

10、 vehicle safety which should avoid a collision at the time of failure, more studies on EVs having the fail-safe drive structure which can run continuously without degrading the function as vehicles after should be ca

11、rried out. Up to now, as EVs with redundant drive structures, the two-wheel in-wheel drive type EV and the four in-wheel drive type EV have been studied with the aim of improving vehicle control and packaging. Invest

12、igated from the viewpoint of vehicle safety however, they have various problems, especially the problem of spin, centering on the failed wheel [7]-[9]. Then, front and rear wheel independent drive type electric vehic

13、les (FRID EVs) [10] (Fig.1) have been developed through various analysis of the drive structure of the current EVs from the viewpoint of the compatibility with the safety and running performance. The developed FRID EV

14、has outstanding function as a vehicle; i. e., the function to improve the acceleration-and-deceleration performance by compensating for load movement [11]-[13] and the fail-safe function to avoid a rear-end collision

15、 by compensating for the lost torque with the healthy drive system at the time of failure [7]-[9]. These outstanding drive performance functions, which the FRID EV has, have been clarified step by step through tests

16、on an official test course using a prototype FRID EV with practical specifications [12][13]. Now, the brake control method which is very important for vehicles is being studied under various road conditions [14], esp

17、ecially the low-? road condition for which safe braking operation is difficult. Fig. 2 shows the operation domain effective in the current anti-lock brake system (ABS) [15]. The current ABS has a problem that it does

18、 not operate in the domain where brake treading strength is small. This means v uwIu IvIwBatteryv uw Iu IvIwSplitterMode DiscriminationM MSxaxbM MVehicle ControllerFig. 1. FRID EV with a drive stru

19、cture that is compatible in the safety and running performance. Fig. 2. Operation domain effective in the current anti-lock brake system (ABS).978-1-61284-972-0/11/$26.00 ©2011 IEEE 4570is crucial to prevent occur

20、rence of the imbalanced lateral force produced between the left and right wheels of the front and rear sides. This fact can be proved from the simulation results when the brake force which causes severe loss of balan

21、ce between each wheel is applied to the four wheels. (2)When the brake torque is applied to one of four wheels As an example of applying the brake force which causes a severe imbalance to the four wheels, the case where

22、 brake force is applied only to the right rear wheel is examined here (Figs. 6(a)-(c)). After stepping on the brake pedal at time t1, the negative rotation moment J generated according to the front and rear lateral f

23、orces whose directions differ with each other makes the body rotate clockwise. After entering the split-? road at time t2, the imbalanced lateral force is maintained on both sides of the front and rear wheels, and the

24、 negative rotation moment continues. As a result, a negative yaw rate rotating clockwise continues to be generated, and then the direction of the vehicle body changes to the right (Fig. 6(b)). Eventually, swerving fr

25、om the running lane is expected (see Fig. 7(b)). Therefore, in order to stabilize behaviors of vehicles at the time of braking, it is crucial for vehicles to prevent unnecessary imbalanced lateral force from being ge

26、nerated between the left and right wheels. (3)Analyzed transient behavior at the time of braking The analyzed transient behaviors of the vehicles occurring when brake force is applied at other conditions including the

27、two above-mentioned examples are summarized in Fig.7. The speed (30km/h) entering the split-? road with ? of 0.1 and 0.3 is the same. The vehicle trajectories from entering the split-? road until stopping are shown. W

28、hen applying the brake force to only the rear right wheel (Fig. 7(b)), the vehicle path swerves most from the entry point. The second example in which the path swerving is large is Fig. 7(d) where brake force is appli

29、ed to the front left wheel and the rear right wheel. The swerving is the smallest when applying brake force to all four wheels (Fig. 7(a)) and stopping time is also the shortest. Accordingly, the analyzed results sho

30、w that the technique of applying brake force to the four wheels while preventing generation of the unnecessary imbalanced lateral force between the left and right wheels is effective. C. Vehicle Transient Caused by

31、 Braking on a Downward Slope Curved Road Finally, as the most dangerous case, analyzed results on the split-? road of the curved downward slope are shown in Fig. 8. When brake force is applied to the four wheels at

32、t2 after the front wheels entered the split-? road with low-? of 0.1 and 0.3 at a speed of 20km/h, the front wheels completely lock at t3. As a result, at t4, the vehicle has stopped, but it is rotated about 90 degre

33、es to the right direction of movement. It is confirmed that the braking operations under road conditions like this result in a dangerous situation. Then, in the following section the brake control method is studied

34、which can stably stop effectively also under such a severe road environment. The validity of the proposed brake control is verified mainly through simulations. Fig.7. Transient behavior of EVs when brake force is appli

35、ed to each wheel (a) Transient characteristics after braking (b) Vehicle trajectory (c) Transient characteristics immediately after entering split-? road. (d) Vehicle dynamicsFig.6. Vehicle dynamics when the brake

36、 torque is applied to one of four wheels. 0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 0100 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 -1000 0 10000 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 -800 -400 00 1 2 3 4 5 6 7 8 9 10 11 12 13 14

37、15 0 0.5 1.00 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 0 15 30Speed [km/h] Slip RatioMechanical Brake [N]Wheel Speed Vehicle SpeedTime [s]Yaw [deg/s]Lateral force [N]t2 t1 t3 t4Fl RlFr RrFl Rl Fr RrFlFrRlRr(a) Transient char

38、acteristics after braking (b) Vehicle trajectory according to Fig. (a) Fig.8. Vehicle dynamics occurring when brake force is applied to all four wheels on the curved road with the downward slope split-? surface.0 0.5

39、 1 1.5 2 2.5 3 3.5 4 -400 -300 -200 -100 0 1000 0.5 1 1.5 2 2.5 3 3.5 4-400 -200 0 200 400 Brake StartTime [s]t1Split- Roadt2t3 t4 t5 FrontRear(a) Four wheels (b) Right rear wheels (c) Two rear wheels (d) Left front