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1、安徽理工大学自动化专业本科毕业设计英文翻译学院(部)：电气与信息工程学院专业班级： 自动化0 班 学生姓名： x x x 指导教师： 讲师 年 月 日Implementation of Fuzzy-PID in Smart Car ControlAbstractAn unmanued smart car control system and the fuzzy-PID control algorithm are produced . A design scheme of fuzzy-PID controller is put forward. The simulation analysis f
2、rom matlab indicated that the dynamic performance of fuzzy-PID control algorithm is better than that of usual PID. Experimental result of smart car show that it can follow the black guide line well and fast-stable complete running the whole trip.Keywords fuzzy-PID; smart car; fuzzy controller; fuzzy
3、 control1 IntroductionIn recent years, many countries are developing unmanned vehicle technology. This gives birth to many new theories and applied technology. Reference1 presents the theory of turn ahead which uses real-time monitoring speed to change the turn-in point dynamically, then it implemen
4、ts the control strategy to achieve a perfect characteristics of steering. Reference2 uses edge detection algorithm to extract track information and adopt P control. Reference3 proposes a efficient, good anti-jamming and adaptive image processing dynamic algorithm which effectively solves the out of
5、track caused by the changes of ambient light and track. Reference4 reconstructs spatial relationships of track and calibrates camera using nonlinear optimization, then it can measure lateral deviation accurately. The above improve vehicle performance in one way but they are all lack of characteristi
6、cs of car movement and based on lots of experiments. A fuzzy-PID control algorithm and a design scheme of fuzzy-PID controller are put forward in this paper. At last, the experimental result is given out to prove the validity of fuzzy-PID.2 Hardware system designTo implement the design of fuzzy-PID
7、algorithm, its necessary to design a hardware system of smart car. Smart car would have a smart control unite which contain detection of guide line, steering angle value, speed value and so on. See details in Fig.1.Fig.1 The functional block diagram of smart car3 Basic principle of fuzzy-PIDIts diff
8、icult for usual PID control algorithm to achieve the best effect. Because, the parameters Kp, Ki, Kd cant adjust to different object or different state of the same object. Fuzzy control is based on fuzzy set and fuzzy logic. Without precise mathematical model it can determine the size of controlled
9、variable according the rule table organized by experience. In general, fuzzy control input variables are based on system error E and error change EC, which is similar to PD control. Such control might have a good dynamic characteristic, but the static performance is not satisfactory.Combining fuzzy
10、control and PID control, this would make a system have both flexibility-adaptablity of fuzzy control and high accuracy of PID control.Fig.2 shows the structure diagram of fuzzy-PID control system, in which fuzzy controller is responsible for selecting a different PID parameter to improve the local p
11、erformance thus increasing over all performance.4 Design of fuzzy-PID controllerSpeed drive motor controller design is similar to the following example for steering gear controller design. Fuzzy controller consists of fuzzification, fuzzy-inference and defuzzification, which are based on the knowled
12、ge base.6 Controller input error and error change, output the parameters Kp,Ki,Kd.Suppose the fuzzy set for E isNB,NM,NS,NO,PO,PS，PM,PB; the fuzzy set for EC、 Kp、Ki and Kd isNB,NM,NS,ZO,PS,PM,PB. The linguistic meanings are: NB = negative big, NM = negative middle, NS = negative small, NO = negative
13、 zero, ZO = zero, PO = positive zero, PS = positive small, PM = positive middle, PB = positive big. So the membership function curves of fuzzy variables E、EC、Kp、Ki and Kd are shown in the Fig.3-Fig.7:Its necessary to establish rule table after finishing fuzzification. According the description of ru
14、le table, 56 fuzzy conditional statements can be summed, which look like If (E is PB) and (EC is PB) then (Kp is PB) (Ki is ZO) (Kd is PB). See details in Tab.1-Tab.3.Then, the last step is defuzzification and making a lookup table. During fuzzy control, the lookup table would be embed into the prog
15、ram. Suppose input value is fixed, the corresponding output value would be found in the table. Actually, this would save much computing time, and the control would become simply.5 Analysis of experimental resultsExperiment used the steering gear model. The simulation circuit were shown in Fig.2. The
16、 usual PID and fuzzy PID algorithm were all simulinked in the Matlab. Responding curves obtained were shown in Fig.8 and Fig.9. The experimental result show that compared with the usual PID, the responding time of fuzzy-PID algorithm is shorter without over swing. The system dynamic performance is i
17、mproved significantly.6 Conclusion and outlookThis paper provided a design scheme for controlling a smart car, which is proved practically and superlatively though experiments. Unmanned smart car is due to the development of computer technology, pattern recognition and intelligent control technique.
18、 Many countries and research groups are doing research in the area. But its a complicated system, which involves a number of technologies. So the development of each technology is important, for it would become the bottleneck of the development of smart car.Stepper motorStepper motor is the electric
19、 pulse signals into angular displacement or linear displacement of the open-loop stepper motor control element pieces. In the case of non-overloaded, the motor speed, stop position depends only on the pulse frequency and pulse number, regardless of load changes, when the driver receives a step pulse
20、 signal, it will drive a stepper motor to Set the direction of rotation of a fixed angle, called the step angle, which the angle of rotation is fixed step by step operation. Number of pulses can be controlled by controlling the angular displacement, so as to achieve accurate positioning purposes; th
21、e same time by controlling the pulse frequency to control the motor rotation speed and acceleration, to achieve speed control purposes.1 WorkInduction motor is a stepper motor, does it work is the use of electronic circuits, the DC power supply into a time-sharing, multi-phase timing control current
22、, this current stepper motor power supply, the stepper motor to work properly , The drive is sharing power supply for the stepper motor, the polyphase timing controller.Although the stepper motor has been widely used, but the stepper motor does not like a normal DC motor, AC motor in the conventiona
23、l use. It must be double-ring pulse signal; power driver circuit composed of the control system can be used. Therefore, it is not easy with a good stepping motor, which involves mechanical, electrical, electronics and computers, and much other specialized knowledge.As the stepper motor actuators, el
24、ectromechanical integration, one of the key products, widely used in a variety of automatic control systems. With the development of microelectronics and computer technology, increasing demand for stepper motor has applications in all areas of the national economy.2 CategoriesNow more commonly used
25、include the reaction of step motor stepper motor (VR), permanent magnet stepper motor (PM), hybrid stepper motors (HB) and single-phase stepper motor.3 Permanent magnet stepper motorPermanent magnet stepper motor is generally two-phase, torque, and smaller, usually 7.5 degree step angle or 15 degree
26、s;Permanent magnet stepper motor output torque, dynamic performance, but a large step angle.4 Reaction Stepper Motor Reaction is generally three-phase stepping motor can achieve high torque output, step angle of 1.5 degrees is generally, but the noise and vibration are large. Reaction by the stepper
27、 motor rotor magnetic circuit made of soft magnetic materials, a number of the stator phase excitation winding, the use of permeability changes in torque.Step Motor simple structure, low production costs, step angle is small; but the dynamic performance is poor.5 Hybrid Stepping MotorHybrid Step Mot
28、or combines reactive, permanent magnet stepper motors of both, its a small step angle, contribute a large, dynamic performance, is currently the highest performance stepper motor. It is also sometimes referred to as Permanent Magnet Induction Stepping Motor. It consists of two phases and the five-ph
29、ase: the general two-phase step angle of 1.8 degrees and the general five-phase step angle 0.72 degrees. The most widely used Stepper Motor. Stepper motor drive for energy saving6 Three-phase stepper motor drive special features:u 180% low torque output, low frequency characteristics of a good runu
30、Maximum output frequency 600Hz, high-speed motor controlu full range of detection of protection (over voltage, under voltage, overload) instantaneous power failure restartu acceleration, deceleration, such as dynamic change in the stall protection function to preventu Electrical dynamic parameters o
31、f automatic recognition function to ensure stability and accuracy of the systemu quick response and high-speed shutdownu abundant and flexible input and output interface and control, versatilityu use of SMT production and three full-mount anti-paint treatment process, product stability and highu ful
32、l range of Siemens IGBT power devices using the latest, to ensure the quality of high-quality7 Basic principlesUsually for the permanent magnet rotor motor, when current flows through the stator windings, the stator windings produce a magnetic field vector. The magnetic field will lead to a rotor an
33、gle of the magnetic field makes the direction of a rotor and the stators magnetic field direction. When the stator magnetic field vector rotating at an angle. As the rotor magnetic field is also transferred from another perspective. An electrical pulse for each input, the motor turning a point forwa
34、rd. It is the angular displacement of the output and input the number of pulses proportional to speed and pulse frequency is proportional to. Power to change the order of winding, the motor will reverse. Therefore, the number of available control pulse, frequency and power the motor windings of each
35、 phase in order to control the stepper motor rotation.8 Induction Stepping Motor8-1 features: Induction, compared with the traditional reactive, structural reinforced with a permanent magnet rotor, in order to provide the working point of soft magnetic materials, and the stator excitation magnetic f
36、ield changes only need to provide to provide the operating point of the consumption of magnetic materials energy, so the motor efficiency, current, low heat. Due to the presence of permanent magnets, the motor has a strong EMF, the damping effect of its own good, it is relatively stable during opera
37、tion, low noise, low frequency vibration. Induction can be seen as somewhat low-speed synchronous motor. A four-phase motor can be used for four-phase operation, but also can be used for two-phase operation. (Must be bipolar voltage drive), while the motor is not so reactive. For example: four phase
38、, eight-phase operation (A-AB-B-BC-C-CD-D-DA-A) can use two-phase eight-shot run. Not difficult to find the conditions for C =, D =. a two-phase motors internal winding consistent with the four-phase motors, small power motors are generally directly connected to the second phase, the power of larger
39、 motor, in order to facilitate the use and flexible to change the dynamic characteristics of the motor, its external connections often lead to eight (four-phase), so that when used either as a four-phase motors used, can be used for two-phase motor winding in series or parallel.8-2 classification：In
40、duction motors can be divided in phases: two-phase motor, three phase motor, four-phase motor, five-phase motor. The frame size (motor diameter) can be divided into: 42BYG (BYG the Induction Stepping motor code), 57BYG, 86BYG, 110BYG, (international standard), and like 70BYG, 90BYG, 130BYG and so ar
41、e the national standards.8-3 the stepper motor phase number of static indicators of terms: very differently on the N, S the number of magnetic field excitation coil. Common m said. Beat number: complete the necessary cyclical changes in a magnetic field pulses or conducting state with n said, or tha
42、t turned a pitch angle of the motor pulses needed to four-phase motor, for example, a four-phase four-shot operation mode that AB -BC-CD-DA-AB, shot eight four-phase operation mode that A-AB-B-BC-C-CD-D-DA-A. Step angle: corresponds to a pulse signal, the angular displacement of the rotor turned wit
43、h said. = 360 degrees (the rotor teeth number of J * run shot), the conventional two, four-phase, the rotor teeth 50 tooth motor as an example. Four step run-time step angle = 360 / (50 * 4) = 1.8 degrees (commonly called the whole step), eight-shot running step angle = 360 / (50 * 8) = 0.9 degrees
44、(commonly known as half step.) Location torque: the motor is not energized in the state, its locked rotor torque (as well as by the magnetic field profile of harmonics caused by mechanical error) static torque: the motor under the rated static electricity, the motor without rotation, the motor shaft
45、 locking torque. The motor torque is a measure of volume (geometry) standards, and drive voltage and drive power, etc. has nothing to do. Although the static torque is proportional to the electromagnetic magnetizing ampere turns, and fixed air gap between the rotor teeth on, but over-use of reduced
46、air gap, increase the excitation ampere-turns to increase the static torque is not desirable, this will cause the motor heating and mechanical noise.智能小车控制中模糊-PID控制的实现摘要：本文设计了一个自动智能小车控制系统和模糊-PID控制算法。 提出了一个设计模糊PID控制器的方案。通过matlab的仿真分析表明,模糊- PID控制算法的性能比一般的PID控制更好。智能小车的试验结果表明它会随黑色的引导线快速并且稳定的走完整个行程。关键词：模
47、糊PID；智能小车；模糊控制器；模糊控制。 1简介近年来,许多国家正在研制无人驾驶的车辆技术。产生了许多新的理论和应用技术。文献1中提出了一个采用实时检测速度从而准确、动态改变小车转向的理论，从而实现转向完美特性的控制策略。文献2中采用边缘检测算法来提取道路信息，并采用了比例控制。文献3提出了一种有效、具有良好抗干扰性的、适应性强的动态图像处理算法。这种算法有效的解决了由环境光线变化以及轨道变化所引起的小车偏离轨道现象。文献4利用非线性最优化重建了轨道和摄像调整间的空间关系，从而使它能够精确的测量出横向偏差。上述方案都从某种意义上改善了小车的性能，但他们都缺少以小车运动和大量实验为基础的小车的
48、特性。这篇文章中提出了一个模糊控制算法以及模糊PID控制器的设计方法。在本文最后,给出了实验结果来证明模糊PID算法的有效性。2硬件系统设计要实现模糊PID控制算法的设计，有必要设计一个智能小车硬件系统。智能小车应该有由道路检测，转角检测，速度检测等构成的智能控制单元。详见图1。图1 智能小车原理框图3模糊PID控制的基本原则用一般的PID控制算法来获得最好的响应是不容易的。因为参数Kp、Ki、Kd不适应于不同的对象，或者同一个对象的不同状态。模糊控制是以模糊集合和模糊逻辑为机车的。不需要精确的数学模型，它可以由用经验建立起来的规则表来确定控制变量的大小。一般来说，模糊控制的输入变量基于系统的
49、误差E和系统的误差变化量Ec。这和比例微分控制相似。这样的控制可能可以获得较好的动态性能，但获得的静态性能不能让人满意。将模糊控制于PID控制结合起来，这就会使系统即具有模糊控制所具有的灵活的适应特性，又具有PID控制的所具有的较高的精确度。图2给出了模糊PID控制系统的结构图，其中模糊控制器的作用是选择不同的PID参数来改善局部响应，进而改善整体的响应。图2 模糊PID控制仿真框图4模糊PID控制器的设计速度驱动电机控制器的设计和下面给出的转向机构控制器设计是相似的。模糊控制器由模糊化、模糊推理、去模糊化组成，这些都是以知识库为基础的。控制器输入为误差及误差变化量，输出为参数Kp、Ki、Kd。假设误差
