外文翻譯---多軸車輛的轉(zhuǎn)向特性

1、<p>　　Turning characteristics of multi-axle vehicles</p><p>　　Abstract：This paper presents a mathematical model for multi-axle vehicles operating on level ground. Considering possible factors related to

2、 turning motion such as vehicle configuration and tire slip velocities, equations of motion were constructed to predict steer ability and driving decency of such vehicles. Turning radius, slip angle at the mass center, a

3、nd each wheel velocity were obtained by numerically solving the equations with steering angles and average wheel velocity as numerical input</p><p>　　Keywords: Multi-axle vehicles; Turning maneuverability; M

4、athematical model</p><p>　　1. Introduction</p><p>　　Track laying running gear has been mainly used in the fields of military and construction for heavy vehicle applications. Recently, running ge

5、ar with pneumatic tires has been expanding to heavy vehicles in such fields, since tire equipped vehicles excel in speed, silence and energy e?-cogency. Several papers have been published on the subject of tractability a

6、nd maneuverability of multi-axle vehicles [1,2]. A theoretical study to evaluate the turning motion of skid steering vehicles was also dev</p><p>　　MODIX, are designed to be equipped with independent wheel d

7、rive and steering, and load control suspensions [4]. The MODIX can turn by normal steering, skid steering, or a mixture of both. Additionally, the conversion from mechanical drive to an electric drive unit controlled by

8、each in-hub motor has been examined [5–7]. A hybrid wheel steer system is being developed to complement the independent drive capability of the in-hub wheel motors. However, there has not been a paper or technical public

9、a</p><p>　　This paper describes a computer simulation model to predict turning characteristics of multi-axle vehicles. The equations of motion for the vehicles are constructed for level ground. Tractate and

10、side forces acting under pneumatic tires due to interaction with the ground are of fundamental importance to predict the motion of vehicles. In the numerical simulation, the brush model based on a physical approach was a

11、dopted for the tire model [8]. The brush model is an idealized representation of tir</p><p>　　In order to determine the turning motion of multi-axle vehicles, the ejects of fundamental parameters such as veh

12、icle speed, steering angles and type of driving system are examined by using specification of an example vehicle. Field tests on multi-axle vehicles were also conducted and compared to the predicted results with the data

13、 numerically obtained by the model. The results demonstrated that the proposed mathematical model could accurately assess the turning characteristics of multi-axle veh</p><p>　　2. Mathematical model of multi

14、-axle vehicles</p><p>　　2.1. Coordinate system and kinematics of the vehicle</p><p>　　Fig. 1 shows coordinate systems used to describe a multi-axle vehicle with velocity vector V and yaw angular

15、 velocity h at the mass center. The coordinate system (X1, X2) is fixed on the level ground with unit base vectors {E1, E2}. A moving coordinate system (x1, x2) is attached to the vehicle, whose origin is located at the

16、mass center, with unit base vectors {e1, e2}. </p><p>　　2.2. Equations of motion</p><p>　　Newton’s second law applied to the vehicle yields:</p><p>　　where m and I are the mass and

17、the moment of inertia for the vehicle, respectively. The frictional force Q is defined under the itch wheel, and xi denotes the position vector of the itch wheel. In a steady state turn, the equilibrium equations for the

18、 vehicle are obtained by setting V and zero.</p><p>　　2.3. Tire slip and frictional forces</p><p>　　Modeling of shear force generation for pneumatic tires has been reviewed by Pacifica and Shar

19、p [8] who covers physical and empirical models. The brush model, an analytical model physically derived, has been widely used for vehicle dynamics studies. The relation between deformations of tire treads and shear force

20、s, i.e., side force and tractate force, is simplified and the model idealizes the representation of tires in the region of contact. The horizontal shear forces acting under the tire due t</p><p>　　In this pa

21、per, the brush model has been adopted to the vehicle model. A schematic slip motion of a tire with slip angle is shown in Fig. 2. The slip velocity vector ViS is defined by the relative velocity of tread surface and the

22、ground as follows:</p><p>　　Where Vi and ViR denote the traveling velocity vector and the peripheral speed vector, respectively, of the itch wheel. A non-dimensional slip ratio S is defined by the ratio of t

23、he norm of slip velocity with the magnitude of the peripheral velocity:</p><p>　　Frictional force yields at the limit of the adhesion and the coincident of yielding friction is expressed as a function of sli

24、p ratio as follows:</p><p>　　where K is a positive constant dependent on the staidness of the tire, and l0 is the maximum coincident of friction. The limit of slip ratio Sm represents the full sliding state

25、of the tire throughout the tread, expressed by Sm =1/K.</p><p>　　Fig. 4 shows the lateral force versus the longitudinal force (braking or traction force) plotted at given values of slip angles (rod) for a ti

26、re with the property of K= 5.0.</p><p>　　As the driving power from the engine is transmitted to the wheel through the deferential, the driving force and the rotational speed of each wheel are influenced by p

27、ower train types. The general type of driving system for multivalve vehicles is illustrated in Fig. 5. Deferential are mounted in each axle to distribute equal tractate force to both side wheels and the rotational speeds

28、 of the wheels depend on the path length of the tires. The property of differential is mathematically expressed as</p><p>　　where Qli is the tractate force or the longitudinal shear force on the ith tire, an

29、d VR0 is the average peripheral velocity of the tires.</p><p>　　3. Experimental evaluation</p><p>　　Field tests were conducted by using two full-scale vehicles. The low speed turning performance

30、 of the vehicles was evaluated on a concrete test ground and on sandy ground. One vehicle was an eight-wheel-vehicle with front-four-wheel-steering, which is identified by vehicle A. The other was a TADANO ALL TERRAIN VE

31、HICLE or vehicle B, which is an eight-wheel-vehicle with all-wheel-steering shown in Fig. 6. The maximum coincident of friction l0 depends on the ground condition. The coercions were mea</p><p>　　Fig. 7 show

32、s the experimental and predicted results of the turning radius versus steering angles. The parameter indicates the average steering angle of the front wheels and, for all-wheel steering; the angles of the rear four wheel

33、s are fixed at a maximum in its steering capability. It is clear that the turning radii of the vehicles A and B decrease as the steering angles increase. The lower line for vehicle B indicates the results of all-wheel st

34、eering with rear steering angles, =13.7°, =23.</p><p>　　4. Numerical simulation and results</p><p>　　4.1. Vehicle response in four wheel steering</p><p>　　In order to evalua

35、te the turning characteristics of multivalve vehicles, the numerical simulation was carried out using the specifications of a full-scale vehicle. The mass is m =24,500 kg and the mass center is located at the geometric c

36、enter. The determination of steering angle of each wheel is shown in Fig. 8 for the case of the first and second axle wheels being steered (4WS: four-wheel steering). Each wheel steering angle d can be obtained geometric

37、ally such that all wheels have a steering </p><p>　　Additionally, the lateral force on the third axle is much larger than the forces on the first and second axles. It was found from the numerical results tha

38、t the sideslip angle of the third axle tires is large and opposite in direction compared to the other tires. </p><p>　　4.2. Effect of rear wheel steering on turning characteristics</p><p>　　The

39、turning radius of vehicles at low speed is expected to decrease if the rear wheels are steered with opposite angles to the front wheels. Fig. 13 shows the steering radius when the tires on the third and fourth axles are

40、inversely steered to the front wheels. The average steering angle of the rear wheels is defined as the angle of an imaginary wheel in the middle of the wheels on the fourth axle as shown in Fig. 13.</p><p>

41、　　The change in turning radius versus rear steering angles at l =1.0m is illustrated in Fig. 14 for the front steering angles, d =10,20 and 30. It is clear that the turning radius decreases considerably as the rear stee

42、ring angle increases. In the design of multi-axle vehicles the steer centers of the front wheels do not generally coincide with the center of the rear wheels, as seen previously.</p><p>　　作者：K. Watanabe，J. Y

43、amakawa , M. Tanaka, T. Sasaki</p><p>　　國籍：American</p><p>　　出處：The National Defense Academy, 1-10-20 Hashirimizu, Yokosuka 239-8686, JapanAvailable online 29 March 2006</p><p><

44、b>　　多軸車輛的轉(zhuǎn)向特性</b></p><p>　　摘要： 本文為平地上操作多軸車輛的數(shù)學模型，考慮有關的可能因素構建轉(zhuǎn)向車輛配置和輪胎滑移速度，如運動預測的可操作性和這些車輛的駕駛效率。車輪中心轉(zhuǎn)彎半徑，滑移角被包含其中，通過車輪角的方程式解決，說明了轉(zhuǎn)折點特征多軸車輛，效果的基本參數(shù)，如車速，轉(zhuǎn)向角度和行駛系統(tǒng)類型，多軸車輛的樣本。此外，實地測試，使用大型車輛進行了評估水平地面上的基本轉(zhuǎn)

45、折點特征</p><p>　　關鍵詞：多軸車輛，可操作性，數(shù)學模型</p><p><b>　　1 引言</b></p><p>　　主要運用于軍事履帶運行車輛和建筑領域的重型車輛，由于輪胎車輛配備擅長在速度，低噪音和高能源效率。最近運行與充氣輪胎的齒輪的規(guī)模不斷擴大至重型車輛的這些領域。已有多份發(fā)表的文件關于多軸車輛的通過性和可操作性，Ren

46、ou和 Chavan 還進行了一個關于防滑方向盤汽車的評估，更近的軍隊車輛，如MODIX，被設計為具有獨立配備四輪驅(qū)動和轉(zhuǎn)向和負荷控制懸浮,MODIX能夠由正常的車輪，滑移車輪或是兩者的混合轉(zhuǎn)動，此外，轉(zhuǎn)換從機械傳動電動驅(qū)動裝置控制每個輪轂電機已審查?；旌纤妮嗈D(zhuǎn)向系統(tǒng)正在開發(fā)，以補充獨立的轂輪馬達驅(qū)動器的能力。然而，有沒有得到全面處理這個問題的論文或技術出版物，并在日志邏輯順序，因為動態(tài)運動的多軸車輛是復雜的現(xiàn)象。</p>

47、<p>　　本文介紹了一種計算機模擬模型來預測多軸車輛的轉(zhuǎn)向特點，汽車運動的微方程構造為平地，牽引力和側(cè)力的作用下充氣輪胎由于與地面交互的基本精神的重要性，來預測車輛的議案，在數(shù)值模擬，基于物理的方法刷模型通過輪胎模型，在接觸區(qū)域里刷模型是理想化的代表輪胎。</p><p>　　為了確定多軸轉(zhuǎn)動車輛的運動，如基本參數(shù)的影響車輛行駛速度，轉(zhuǎn)向角度和駕駛系統(tǒng)類型檢查的一個例子，多軸車輛的實地測試也進行與數(shù)

48、字數(shù)據(jù)的預測結(jié)果相比得到的模型。結(jié)果表明，提出了數(shù)學模型，可以準確地評估多軸車輛的轉(zhuǎn)向特性</p><p>　　2 多軸車輛的數(shù)學模型</p><p>　　2.1坐標系統(tǒng)和車輛的運動學</p><p>　　圖1所示的坐標系統(tǒng)，用來形容多軸車輛的速度矢量V和偏航角速度重心Q。坐標系統(tǒng)（X1，X2）的水平地面上的固定單位基向量{E1，E2}，連接到一個移動的坐標系統(tǒng)（

49、X1，X2）的車輛，其原產(chǎn)地是在質(zhì)量中心位于單位基向量{E1，E2}，車輛n個輪子一方獨立懸掛彈簧和具有相同屬性的支持車身。</p><p><b>　　2.2運動方程式</b></p><p>　　牛頓第二定律應用于汽車產(chǎn)量：</p><p><b>　?。ǎ?lt;/b></p><p>　　其中m和

50、I分別是車輛的質(zhì)量和慣性矩，摩擦力Q是指車輪受到的力，以及表示車輪的位置坐標，在穩(wěn)定的轉(zhuǎn)向中，汽車運動方程式中包含有V和Q。</p><p>　　2.3輪胎滑行和摩擦力</p><p>　　充氣輪胎產(chǎn)生剪切力的建模已由Pacifica和Sharp報道過其中包含有物理和實證模型。刷模型是分析模型物理派生的，已被廣泛用于車輛動力學研究。輪胎的胎面和剪切力，即側(cè)向力和牽引力變形之間的關系，簡化和

51、模型理想化輪胎在接觸區(qū)域的代表性。水平剪切力下輪胎由于交互與地面都假定為線性依賴胎面從胎面基地位移。</p><p>　　圖1轉(zhuǎn)彎運動和平衡系統(tǒng)下的多軸汽車</p><p>　　在這篇文章中，刷模型已經(jīng)被車輛模型采用了，一種具有防滑原理的輪胎如圖2.</p><p>　　其中和V代表行駛速度矢量和外圍速度矢量。一個無量綱滑移率S的定義是規(guī)范的滑移速度與規(guī)模的周邊速度

52、比值。</p><p><b>　　圖2汽車的滑行</b></p><p>　　圖3顯示了輪胎的摩擦力。摩擦力這樣計算：</p><p>　　圖4顯示了橫向與縱向力，其中K=5.0.</p><p>　　由于驅(qū)動力是由發(fā)動機轉(zhuǎn)移到車輪上，驅(qū)動力和每個車輪轉(zhuǎn)速受到列車類型的影響。一般類型的多軸車輛驅(qū)動系統(tǒng)如圖5所示。差距是

53、安裝在每個車軸分配均等的牽引力兩側(cè)車輪和車輪的轉(zhuǎn)速取決于輪胎路徑長度。差距的特性被表現(xiàn)為約束方程：</p><p><b>　　3實驗結(jié)果分析</b></p><p>　　使用兩輛滿載的車輛進行了實驗，分別在具體的實驗平地和沙地上進行了低速實驗評估。其中一輛車是前四輪轉(zhuǎn)動的八輪車輛，這輛車標記為A，另一輛被標記為B，這是一輛全輪轉(zhuǎn)動的八輪車，最大的摩擦情況取決于陸地的

54、情況。在田間試驗，2個轉(zhuǎn)向類型被檢測，一種是前四輪轉(zhuǎn)動，另一中是全輪轉(zhuǎn)動的情況。轉(zhuǎn)向半徑相對于的實驗和實驗結(jié)果的預測。該參數(shù)表明了全四輪轉(zhuǎn)動情況相對于全輪轉(zhuǎn)動情況的平均轉(zhuǎn)角。后四輪的轉(zhuǎn)角在它轉(zhuǎn)向能力的限度內(nèi)固定為最大。實驗表明隨著轉(zhuǎn)角的增加A車和B車的轉(zhuǎn)角半徑逐漸降低。低線表明車輛全輪轉(zhuǎn)向結(jié)果你表現(xiàn)在后輪轉(zhuǎn)向角度，全輪轉(zhuǎn)動的轉(zhuǎn)彎半徑明顯降低。</p><p><b>　　4數(shù)據(jù)模擬以及結(jié)果</b&

55、gt;</p><p>　　為了評估多輪轉(zhuǎn)動的特性，在一輛全面的汽車上進行了數(shù)值模擬，汽車質(zhì)心位于幾何中心處。在模擬中，假定有一個假想的車輪在中東的兩只輪子在第一軸和角的虛盤是用來代表平均前輪的角度。一個摩擦力的圖顯示作用于車輛的穩(wěn)定狀態(tài)是顯示在圖11。在案件的車輛牽引力的恭敬，左右輪情況相同。很顯然，這些數(shù)字，縱向力在第一個車軸車輪工作在相反的方向，即牽引力作用在輪胎，另一方面，牽引部隊采取行動的其他車輪。此外

56、，側(cè)向力對第三軸是遠遠大于部隊在第一、二軸。它被發(fā)現(xiàn)的數(shù)值結(jié)果，側(cè)滑角的第三軸輪胎大方向相反相對于其他輪胎。車輛的轉(zhuǎn)彎半徑在低速度預計將減少，如果是指導后輪與前輪相反角度。圖13顯示了轉(zhuǎn)向半徑時，輪胎在第三和第四軸的正轉(zhuǎn)向前輪。轉(zhuǎn)向角度的后輪的轉(zhuǎn)向中心確定的行的前面和平行于第三軸。</p><p>　　作者：K. Watanabe，J. Yamakawa, M. Tanaka, T. Sasaki</p&g