浅析四轮转向系统在工程机械中的应用中英文

1、浅析四轮转向系统在工程机械中的应用中英文Four wheel steering system is analysed in the application of engineering machinery 工程机械广泛地被应用到设计生产建设的各个方面。工程机械通常机身较长，转向不灵活，转弯半径大，与之相矛盾的是，工程机械的作业场地通常都狭窄，工作条件差，障碍物多，行驶路面凹凸不平，而且工程机械要求频繁转向。这就提出一个迫切的任务，即如何减小工程机械的转弯半径，增加工程机械作业行走的稳定性和可靠性，即我们需要一种转向性能良好的工程机械转向系统。Engineering machinery is w

2、idely applied to design every aspect of production and construction. Engineering machinery is longer than the fuselage, usually not flexible steering, the turning radius is big, and paradoxically, engineering machinery operation site is usually small, poor working conditions, obstacles, more road un

3、even, but also frequently turned to mechanical engineering requirements. It puts forward an urgent task that how to reduce engineering machinery turning radius, increase walking engineering machinery operation stability and reliability, namely, we need a kind of engineering machinery to the good per

4、formance of steering system.四轮转向系统是这些年来得到发展和应用的一种转向系统，从目前现状看来，进口的工程机械采用四轮转向技术屡见不鲜，可是国内对这一技术的研究几乎还处于空白。 2四轮转向系统的工作原理 四轮转向系统通常包括前轮转向、全轮转向、以及斜行转向三种模式。Four-wheel steering system in these years the development and application of a steering system, from the current situation, it seems, imports of construc

5、tion machinery with four-wheel steering technique, but domestic research on this technology is still in a blank almost. 2 four-wheel steering system working principle of four-wheel steering system usually includes the front wheel steering, all-wheel steering, and oblique lines to three modes.前轮转向就是只

6、有前轮进行左转或者右转。这是一种常用的转向方式，此时，前外轮的弯道行驶半径大，驾驶员易于用前外轮是否避过障碍来估计整机的行驶路线。The front wheel steering is only front wheel to turn left or turn right. This is a common way of steering, at this point, the ocean shipping before driving bend radius is large, the driver is easy to use ocean shipping before ever avoi

7、d barriers to estimate the whole route.全轮转向就是前后轮同时偏转的转向方式，此时，前后轮的偏转方向相反，即前轮左转时后轮右转，前轮右转时后轮左转。这种转向方式往往用于对机动性有特殊要求或机架特别长的机械。All-wheel steering is the deflection of the front and at the same time, at this point, the deflection of the front and back in the opposite direction, namely the front wheels tur

8、n left turn right when the rear wheels and front wheels turn right when the left rear wheel. This way to often used for very long robotic mobility have special requirements or frame.斜行转向是前后轮偏转方向相同的一种转向方式。斜行时，能从斜向靠近或者离开作业面。而且在斜坡上斜行作业时，能提高其横向稳定性。为了防止各车轮在转向时作侧向滑动，增加转向阻力，加速轮胎磨损。各车轮必须作纯滚动。只有当所有车轮的轴线在转向过程

9、中都交于一点时，各车轮才能作纯滚动，此速度瞬时中心就称为转动中心。Front and rear wheels steering is oblique line direction deflection of the same a way of steering. From oblique oblique line, can close to or leave the operation. And on slope inclined line operations, can improve the lateral stability. In order to prevent the wheel

10、in turn make the lateral sliding, increase the steering resistance, accelerate the tyre wear. Each wheel must be pure roll. Only when all of the axis of the wheel in turn pay little, in the process of the wheel to make pure roll, the instantaneous center of velocity is called the center of rotation.

11、而转向控制驱动单元作为工程机械一个重要的控制单元经历了机械式、液压式、电动式向组合式发展的历程，技术上日趋成熟。图2所示为一种数字式电液转向控制系统的原理图。And steering control drive unit as an important engineering machinery control unit. Experienced mechanical, hydraulic, electric to modular development, mature technology. As shown in figure 2 is a kind of digital electro-

12、hydraulic steering control principle diagram of the system.其工作原理为：当方向盘偏转后，转向信号经过控制器分析计算，判断给出的偏转方向以及偏转角度，然后输出所需要的占空比PWM信号到电磁阀，控制阀的开口大小。同时，由定量泵给系统供油，通过控制电磁阀的开口大小以控制转向液压缸的流量和压力，从而实现各个转向轮的偏转角度的控制。而且，该系统采用并联连接，四个车轮的转向可以独立控制。Its working principle is: when the steering wheel deflection, steering signal aft

13、er controller analysis and calculation, the judgment given by the direction of the deflection and deflection Angle, then the duty ratio of PWM signal output need to electromagnetic valve, control valve opening size. At the same time, by quantitative pump to the fuel supply system, by controlling the

14、 solenoid valve opening size to control the flow and pressure of the steering hydraulic cylinder, so as to realize the control of the steering wheel deflection Angle. Moreover, this system adopts parallel connection, four wheel steering can be independently controlled.转向控制单元以定频率重复这一过程，控制工程机械快速跟踪转向指令

15、，实现精确转向。与工程机械传统液压转向系统相比，该系统取消了方向盘与转向器之间的机械连接，布置灵活，操作轻便，转向特性由软件决定，控制灵活，为闭环控制，转向精度高。3转向控制系统的设计3.1系统硬件设计 控制系统主控制器的选择直接影响到转向控制系统的性能。考虑到大部分工程车辆自身结构复杂的情况，我们在系统设汁中采用高性能DSP处理器TMS320LF2407A。这种芯片指令执行速度快( 30MIPS)，具有32K片内Flash程序存储器，可扩展的外部存储器有192K，因此可以在片上实现较复杂的控制算法。芯片拥有两个事件管理模块，8个PWM通道，16路10位A/D转换器，能够充分满足转向系统PWM

16、控制信号发出、车轮偏向角度信号A/D等的要求。同时也具有串行通信接口( SCI)和串行外设接口(SPI)，方面的与上位机的的通信以及软件编程、故障诊断等等。为了方便系统的扩充以及实现工程车辆的群控制和远程控制，我们通过使用TMS320LF2407A芯片中的CAN控制模块，在系统设计用引入的CAN现场总线控制技术，控制系统包括几个基本模块模拟量输入模块开关量输入输出模块、PWM控制模块、显示模块设计、通信模块设计、电源模块设计等。Steering control unit to repeat this process a fixed frequency, control engineering

17、machinery fast tracking to the directive, achieve precise steering. Compared with the traditional engineering machinery hydraulic steering system, the system cancelled the mechanical connections between steering wheel and steering, flexible layout, convenient operation, turning performance is determ

18、ined by software, flexible control, closed-loop control, to high precision. 3 steering control system design of the 3.1 control system the choice of the main controller of the system hardware design directly affect the performance of the steering control system. Considering that most of the engineer

19、ing vehicle complex structure itself, in our system is designed using high performance DSP TMS320LF2407A. The chip instruction execution speed (30 MIPS), with 32 k on chip Flash program memory, extensible external memory is 192 k, so it can realize complex control algorithm on the piece. Chip has tw

20、o event management module, PWM channel 8, 16 road 10 bit A/D converter, PWM control signal, can fully meet the steering system wheel deflection Angle signal A/D, etc. Also has a serial communication interface (SCI) and the serial peripheral interface (SPI), and in communication of upper machine and

21、the software programming, troubleshooting, etc. In order to facilitate expansion of the system and achieve the group of control engineering vehicles and the remote control, we CAN control module by using TMS320LF2407A chip, the system design by introducing the CAN field bus control technology, contr

22、ol system includes several modules of basic analog input module, switch input and output module, PWM control module, display module, communication module design, power supply module design, etc.对于模拟量输入模块，主要为轮胎偏转角度的检测信号。如前面所述，由于在转向过程中，要求轮胎具有同步性，否则就会引起轮胎的磨损和转向后行走过程中的不稳定，所以要求转角传感器具有很高的精度，为此我们在设计中选用了德国A

23、SM公司AWS系列角度传感器。该传感器线性度好、测量范围大、输人电压范围广、能够在雨雪灰尘和震动等工况下可靠工作，适宜于工业应用。系统设计中，转向精度可以达到0.50。For analog input module, mainly for the tyre deflection Angle of the detection signal. As described earlier, because in the process of steering, the tire with synchronicity, otherwise it will cause tire wear and turn

24、s to walk after the process is not stable, so the required Angle sensor of high accuracy, therefore in our design, we chose Germany ASM company AWS series Angle sensor. This sensor has good linearity, large measuring range, wide input voltage range, able to work in the rain and snow dust and vibrati

25、on and other working conditions is reliable, suitable for industrial application. System design, steering precision can reach 0.50.显示模块设计主要用于车辆在开机后显示自检结果，以及转向过程中的状态显示等，为故障诊断与排除提供依据。Display module design is mainly used in vehicles at boot after self-checking result, and the status is displayed in the

26、 steering process, provide the basis for failure diagnosis and elimination.通信模块的设计中，主要为CAN总线通信设计。在设计的转向系统中具有5个CAN通信站点。其中DSP芯片所在为主站点，其余四个站点分别分布，以利于系统移植和系统扩容。另外，在系统设计上进行了冗余设计，4个子站可以分别连接传感器件，通过CAN总线检测相应位置处的轮胎转角，做到就近连接，提高系统的抗干扰能力。3.2系统软件设计 软件设计是系统设计的重要部分，在DSP硬件平台上，控制算法的升级换代主要通过软机更新实现。在本系统的设计中，我们采用了TM532

27、0系列芯片的集成开发软件ccs在上位机利用C语言进行开发。本系统的软件采用模块化设计方法，系统由若干模块组成，分别完成不同的功能，它们包括系统自检和初始化模块、AD采样转换模块、控制计算和控制信号生成模块、通信模块、键盘扫描模块、显示模块等。其中系统信号采集过程包括几个模块的运行，如AD采样转换模块、通信模块、键盘扫描模块和其他一些中断服务程序等。4结论 根据系统转向系统的原理和对车轮转向的特殊要求，设计了一种四轮转向系统。系统采用先进的DSP系统设计技术，系统硬件结构简洁，控制算法软件升级方便。系统设计中引入了CAN现场总线技术，使得系统易于扩展，信号传输稳定可靠，抗干扰性能进一步提高。Th

28、e design of communication module, mainly for the CAN bus communication design. In the design of the steering system has five sites CAN communication. Of DSP chip's main site, the rest four site distribution, respectively, to facilitate system transplantation and system capacity. In addition, the

29、 system design on the redundancy design, four sub-stations CAN respectively connected to the sensor, through the CAN bus testing Angle to the corresponding location of the tires, do nearby connection, improve the anti-interference ability of system. 3.2 system software design, software design is an

30、important part of system design, on the DSP hardware platform, the control algorithm is upgrading is mainly through software updates. In the design of this system, we adopted TM5320 series chip integration development software using C language to develop CCS in the upper machine. The software adopts the modular design method