外文翻译--汽车ABS技术及其发展趋势

附 录 附录 A. Car ABS Technology and Development Trend In the car before the emergence of abs, used car is the open loop brake system. Its characteristic is the brake torque only and drivers of the size of the manipulation of the force, braking force distribution regulation and the size of the brakes on and type. With no wheel the motion of feedback signal measurement, cant know during wheel brake speed and holding in death, car you may adjust accordingly wheel cylinder or the gas chamber of the size of the brake pressure. So in an emergency brake, inevitably appear wheel on the ground, holding in death dragged the phenomenon of sliding. When the wheel lock, the ground of the performance was poor, the lateral attached can provide the lateral adhesion is small, car by external force in any minute under the action of will appear direction, easily happened instability problems of traffic accidents. In the wet pavement or snow and ice on the road, the direction of brake the instability of the phenomenon can more serious. towing It is through the basic function of sensors wheel each transient state of motion, and according to the motion correspondingly adjust the size of the brake torque in to avoid the wheels holding in death, it is a phenomenon of closed-loop brake system. It is the electronic control technology in cars of the most successful application project, one of auto brake antilock brake systems can make the car in the braking maintain stability and shorten the direction braking distance, effectively improve the driving safety. Car ABS can say is the most important car safety history of the three great inventions (the other two are airbag with seat belt), ABS is also other safety device (such as ESP driving dynamic stability system and EBD braking forces based distribution system) Because money spent too big, ABS the practical use of the early railway vehicle or aircraft. 70 s, digital electronic technology and large scale integrated circuit, for the rapid development of ABS system lays a foundation to practical application. Bosch company in 1978 first launched the digital electronic control unit of the brake system, and ABS2 Bosch holding device in the Mercedes Benz, which opened on the modern ABS system development sequence Although the Bosch ABS2 of electronic control device is a separation of the components, but due to the digital electronic control device and analog electronic control device, the reaction speed, compared to the control accuracy and reliability are significantly improved, therefore, Bosch ABS2 control effect already is quite good. From then on, Europe, America and Japan, many professional company and brake car companies have developed a variety of ABS system. According to statistics, the whole world has more than 60% of new cars equipped with ABS device. When the car brake wheel speed and the differences between body speed, can lead to the wheel and the road, when the wheel slippage between produce pure rolling way and the pavement at contact, the slip rate is zero, and wheel lock the slip rate is 100%. When the slip rate between 10% 30%, the largest transfer of power. The basic principle of braking antilock brake system (2, 3 is based on the above research, through the control regulation system in power, braking process, to the wheel in the slip rate control, within the scope of the right to obtain the best braking effect. ABS system hardware mainly by the wheel sensor, electronic control devices, brake pressure regulator three major components, constitute a to the slip rate is the control of the target of the closed-loop control system. The wheel speed sensor and the data transfer to the electronic control device. Control device is a microprocessor, according to the wheel speed sensor signal to calculate the speed of the car. In the braking process, reducing speed and control device of programmed ideal reducing the speed of characteristic curve in comparison. If control device judge the wheel reducing speed too large and the wheel will embrace died, signal to hydraulic regulator, hydraulic regulator is according to the control device of the signal to the brake wheel cylinder of hydraulic control (the boost, the pressure or blood pressure). Brake pressure to adjust the frequency of the cycle up to 6 20 H z. ABS technology at the core of theproblem is the control algorithm of research. The control car ABS is a complex, essential nonlinear control problem. In recent years, domestic and foreign scholars in the control of ABS calculate Method on the many theoretical research, mainly in the following several control methods. Now automotive ABS system most of the products are the addition, subtraction speed control, and additional threshold some auxiliary threshold, not involve specific mathematical model. Threshold control for nonlinear systems is an effective control method. In the braking process, can be a primary angular velocity threshold, when actual angular velocity over the threshold, the controller order to release, the wheel brake pressure to rotate faster； A Angle acceleration, when the threshold of angular velocity to reach this threshold, controller and issue commands to control moment, increased, and the wheel as slow movement. Can use a wheel angular velocity sensor as a single wheel signal, and electronic controller in set reasonable add, subtract speed threshold method, can come true to the embrace of the brake cycle. Logic threshold control the fault is that control system of the various threshold and the holding time is from repeated test that experience, and no sufficient data the theoretical basis of the stability of the system and the quality is difficult to evaluation. The optimal control method is based on state space method of modern control theory method. The optimal control method and threshold control method is different, it is a kind of based on the analysis of the model control method. The idea is based on the abs all the control requirements, according to the principle of optimization for brake antilock brake system optimal control goals. This control method is co nsidered the control process of state changes course and make the control process smoothly； Defect is the control effect of quality mainly depends on the mathematical model of the system, quality control is difficult to accurately. The classic of PID control parameters setting is set up on the basis of gather together in try, as long as the scene setting PID parameters, you can get right better control effect. In the ABS in a definition of the expected sliding rate S and actual sliding rate for the input of the difference of the PID, the PID control algorithm is calculate control air pressure value feedback to brake system, a typical feedback control. Its defect is control effect quality depends on the accuracy of the parameter setting. Fuzzy control is based on experience of the rules of the control, and have not rely on the mathematical model of the object, easy to use the experience, knowledge is robust and simple practical. Control rules to the law of thinking. Defect is no effective general calculation method, can only rely on industrial automation instrument and a plan of the device experience and repeated test. By automobile braking antilock brake the basic principle of the braking process, it is known that the nature of the problem is to the wheel the slip rate control adhesion coefficient in the peaks of the Sk, the sliding mode variable structure according to the system of the state, and deviation and at that time, in different derivative value area, in order to control the ideal switch mode switch co ntrol the amount of and symbols, in order to ensure that the system in sliding area is small, within the scope of the state trajectory S sliding in the pitch curve sliding into a control target tsinghua university song jian and other car braking process according to the physical nature of international proposed first to brake dissipation power as the target of the control method. Considering the car of the deceleration process, in fact, is the average kinetic energy of the car into other forms of energy dissipation process. Accordingly, if you take the reasoning brake friction power (or says dissipation power) maximum control targets of ABS, have the potential to give consideration to the braking stability and brake performance. This method than the threshold method has good stability, high efficiency of braking, strong adaptability and control of road surface features obvious etc. Characteristics. Research shows that the control method can have a good application prospect. Drive torque system (hereinafter referred to the ASR) is perfect and added. ABS ASR system can improve the car is in the most slippery road stability and acceleration of the electronic device. Its role is mainly through the control engine torque and a car braking system means to control the driving force, to prevent the wheels idling sliding, maintain the best driving force. ABS guarantee The car braking process, the stability of the direction is guaranteed the car ASR process (beginning, the direction of the acceleration) stability and handling. Many of the cars, the modern electronic control device equipped with ABS ASR electronic control signal devices to exchange interface. And ASR and a major part of the ABS (such as electronic controller, wheel sensor, brake pressure regulators) can be used with or Shared with the car with the ABS ASR system, just the premise, differential control valves and engine control cylinder engine can. This shows, ABS and ASR combination, can make full use of the relevant parts of the car, and active safety will be more assured. Vehicle stability control device (hereinafter referred to as VSC) use two sensors were sensor car yaw-rate and lateral acceleration, and car will shift to Angle and the actual direction are compared. When it found the car is not according to the intention of motorists road, immediately sent to the ASR and ABS correction signal, indicating they take measures to make the car to the correct direction. These system although functions and the structure is different, but the work is similar to the process is sensor signal, she is calculated, the execution processing ECU institutions take corresponding actions. In the system composition, pick the accuracy of the sensor signal directly influence the results of ECU, additional, wheel sensor most is installed in the bad environment, especially near to heat resistant, vibrationresistant sex, the magnetic, corrosion resistance has high request, to the improvement of the performance of the sensor is very important. ABS and electronic throttle control system, electronic all control type (or half controlled) suspension, electronic control four-wheel steering, electronic control hydraulic turn To the electronic control, automatic transmission, cruise control system, global positioning system, etc. Various kinds of electronic control system, can make the combined use of car movement remains in the best state. Along with the electronic control units in car has more and more application, vehicle electronic equipment of the data communication between becomes more and more important, the distributed control system for infrastructure automobile vehicle electronic network system is very necessary. Large amounts of data exchange, high reliability and rapid sex is cheap to automobile electronic network system requirements. The network system, the processor independent operation, the control to improve the performance of the car on something, and in the other processors need to provide according to service. When The structure of the network inside the car relies mainly on the bus transmission technology. Car through a kind of communication is bus transfers of agreement will car electronic control units (engine, ABS, automatic transmission, etc.), intelligent sensor, intelligent instrument, and link up a car interior network. Its advantages are: reduced the number of cable and wire harness in volume, improve the electronic system reliability and maintainability； The general sensors, achieve the purpose of sharing data； Improve the flexibility of the system, that is, through the system software can realize the change of system function. Car ABS technology has been acknowledged as the world, ABS change Good the car brake performance, and the shorter the braking distance. Avoid the wheel lock so as to avoid the loss of car to ability, lose the direction stability of the phenomenon. It would be expected that the recent all kinds of vehicles will be equipped with the technology. Of course, ABS technology is still have defects, such as the stability of system still need to improve, control algorithm of further research and improvement. Through the simulation shows, in the design of fuzzy controller, through the adjustment of the fuzzy controller membership functions, the error in the basic fuzzy subsets of domain non-uniform distribution and ZO interval of the retreat to small enough, without any increase in the control strategy of the case, make the steady-state error of the fuzzy controller is greatly reduced, has the good control effect, short setting time, no overshoot, the improved fuzzy controller in steady precision at the same time, continued to parameter time-variance and fuzzy controller of interference has strong adaptability. All in all, this method improves the fuzzy control the system steady control precision, to impro ve the system dynamic and static quality. Due to the adjustment of the fuzzy controller membership function is very convenient, and therefore, this method is simple and useful for the fuzzy controller is widely used, provide an easy method. 附录 B. 汽车 ABS 技术及其 发展趋 势 在汽车防抱死制动系统出现之前 , 汽车所用的都是开环制动系统。其特点 1, 2 是制动器制动力矩的大小仅与驾驶员的操纵力、制动力的分配调节以及制动器的尺寸和型式有关。由于没有车轮运动状态的反馈信号 , 无法测知制动过程中车轮的速度和抱死情况 , 汽车就不可能据此调节轮缸或气室制动压力的大小。因此在紧急制动时 , 不可避免地出现车轮在地面上抱死拖滑的现象。当车轮抱死时 , 地面的侧向附着性能很差 , 所能提供的侧向附着力很小 , 汽车在受到任何微小外力的作用下就会出现方向失稳问题 , 极易发生交通事故。在潮湿路 面或冰雪路面上制动时 , 这种方向失稳的现象会更加严重。汽车防抱死制动系统 ( Antilock Braking System 简称 ABS)的出现从根本上解决了汽车在制动过程中的车轮抱死问题。它基本功能就是通过传感器感知车轮每一瞬时的运动状态 , 并根据其运动状态相应地调节制动器制动力矩的大小以避免出现车轮的抱死现象 , 因而是一个闭环制动系统。它是电子控制技术在汽车上最有成就的应用项目之一 , 汽车制动防抱死系统可使汽车在制动时维持方向稳定性和缩短制动距离 , 有效提高行车的安全性。 汽车 ABS 可以说是汽车安全历史 上最重要的三大发明之一 (另外两个是安全气囊与安全带 ),ABS 也是其他安全装置 (如 ESP 行车动态稳定系统与 EBD刹车力分配系统 )的基础。精于汽车电子技术的德国博世 ( Bosch)公司研发 ABS 系统的起源要追溯到1936 年 , 当年博世申请了机动车辆防止刹车抱死装置 的专利。 1964 年 (集成电路诞生 )博世公司再度开始 ABS 的研发 , 最后有了 通过电子装工业仪表与自动化装置置控制来防止车轮抱死是可行的 结论 , 这是 ABS 名词在历史上第一次出现。世界上第一具 ABS 原型机于 1966 年出现 , 向世人证明 缩短刹 车距离 并非不可能。因为投入的资金过于庞大 , ABS 初期的应用仅限于铁路车辆或航空器。 70 年代后期 , 数字式电子技术和大规模集成电路的迅速发展 , 为 ABS 系统向实用化发展奠定了基础。博世公司在 1978 年首先推出了采用数字式电子控制装置的制动防抱系统博世 ABS2, 并且装置在奔驰轿车上 , 由此揭开了现代 ABS 系统发展的序 幕。尽管博世 ABS2 的电子控制装置是由分离元件组成的 , 但由于数字式电子控制装置与模拟式电子控制装置相比 , 其反应速度、控制精度和可靠性都显著提高 , 因此 , 博世 ABS2 的控制效果已相 当理想。从此以后 , 欧、美、日的许多制动器专业公司和汽车公司相继研制了形式多样的 ABS 系统。据统计 , 目前全世界已有超过 60%的新车装有 ABS 装置。 汽车制动时由于车轮速度与车身速度之间存在着差异 , 会导致车轮与路面之间产生滑移 , 当车轮以纯滚动方式与路面接触时 , 滑移率为零 , 而车轮抱死时其滑移率为100% 。当滑移率在 10% 30% 之间时 , 传递最大的制动力。制动防抱死系统的基本原理 2, 3 就是依据上述研究成果 , 通过控制调节制动力 , 在制动过程中 , 把车轮滑移率控制在合适的范围内 , 取得 最佳的制动效果。 ABS 系统硬件构成主要由轮速传感器、电子控制装置、制动压力调节器 3 大部分组成 , 构成一个以滑移率为控制目标的闭环控制系统。传感器测量车轮转速并这一数据传送至电子控制装置上。控制装置是一个微处理器 , 根据车轮转速传感器信号来计算车速。在制动过程中 ,减速度与控制装置中预先编制的理想减速度的特性曲线相比较。如果控制装置判断出车轮减速度太大和车轮即将抱死时 , 就发出信号给液压调节器 , 液压调节器就根据控制装置的信号对制动轮缸的油压进行控制 (升压、保压或降压 )。制动压力调节循环的频率可达 6 20H z。 ABS 技术的一个核心问题就是控制算法的研究。汽车 ABS 的控制是一个复杂的、本质非线性的控制问题。近年来 , 国内外学者对 ABS 的控制算 法进行了很多理论研究 , 主要有以下几种控制方法。目前汽车 ABS 系统绝大多数产品都是采用加、减速度门限值控制 , 并附加一些辅助的门限值 , 并不涉及具体的数学模型。门限控制是对非线性系统的一种有效控制方法。在制动过程中 , 可以预选一个角速度门限值 , 当实际的角速度超过此门限值时 , 控制器发出指令 , 开始释放制动压力使车轮得以加速旋转 ； 一个角加速度门限值 , 当车轮的角速度达 到此门限值时 , 控制器又发出指令 , 使控制力矩增大 , 车轮作减速运动。可以采用一个车轮角速度传感器作为单轮信号 , 同时在电子控制器中设置合理的加、减速度门限值 , 就可以实现防抱制动的循环。逻辑门限控制的缺点在于控制系统中的各种门限及保压时间都是从反复试验中得出的经验数据 , 而无充分的理论依据 , 系统的稳定性等品质难以评价。最优控制方法是基于状态空间法的现代控制理论方法。它可以根据车辆 地面系统的数学模型 ,采用状态空间的概念 , 在时间域内研究汽车防抱死制动系统。最优控制方法和门限值控制方法不同 ,它是一种基 于模型分析的控制方法。其思路是根据防抱死制动系统的各项控制要求 , 按照最优化的原理来求得制动防抱死系统的最优控制目标。这种控制方法的优点是考虑了控制过程中状态变化的历程而使控制过程平稳 ； 缺点是控制效果的优劣主要依赖于系统的数学模型 , 控制质量难以准确把握。经典 PID 控制的参数整定是建立在试凑基础上的 , 只要现场整定 PID 参数合适 , 就会得到较好的控制效果。 在 ABS中定义期望的滑移率 S 与实际滑移率之差为 PID 的输入 , 由 PID 控制算法算出控制气压值反馈给制动系统 , 构成典型的反馈控制。其缺点是控制 效果的好坏依赖于参数整定的准确度。模糊控制是基于经验规则的控制 , 具有不依赖对象的数学模型 , 便于利用人的经验知识 , 具有鲁棒性强和简单实用等优点。控制规则符合人的思维规律。缺点是没有有效通用的计算方法 , 只能依靠设工业仪表与自动化装置计者的经验和反复调试。由汽车防抱死制动的基本原理可知 , 其制动过程的本质问题是把车轮的滑移率控制在附着系数的峰值点 Sk, 则滑动模态变结构根据系统当时的状态、偏差及其导数值 , 在不同的控制区域 , 以理想开关的方式切换控制量的大小和符号 ,