安徽理工大学毕业设计英文翻译_大学毕业设计英文翻译

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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 Control

Abstract—An 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 from 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 control 1 Introduction In recent years, many countries are developing unmanned vehicle technology.This gives birth to many new theories and applied technology.Reference[1] presents the theory of turn ahead which uses real-time monitoring speed to change the turn-in point dynamically, then it implements the control strategy to achieve a perfect characteristics of steering.Reference[2] uses edge detection algorithm to extract track information and adopt P control.Reference[3] proposes a efficient, good anti-jamming and adaptive image proceing dynamic algorithm which effectively solves the out of track caused by the changes of ambient light and track.Reference[4] 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 characteristics 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 design To implement the design of fuzzy-PID algorithm, it’s neceary 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.1.1

Fig.1 The functional block diagram of smart car 3 Basic principle of fuzzy-PID It’s difficult for usual PID control algorithm to achieve the best effect.Because, the parameters Kp, Ki, Kd can’t 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 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 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 performance thus increasing over all performance.2Design of fuzzy-PID controller Speed 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 knowledge base.[6] Controller input error and error change, output the parameters Kp,Ki,Kd.Suppose the fuzzy set for E is{NB,NM,NS,NO,PO,PS，PM,PB};the fuzzy set for EC、Kp、Ki and Kd is{NB,NM,NS,ZO,PS,PM,PB}.The linguistic meanings are: NB = negative big, NM = negative middle, NS = negative small, NO = negative 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: 3

It’s neceary to establish rule table after finishing fuzzification.According the description of rule 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 program.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.Analysis of experimental results

Experiment used the steering gear model.The simulation circuit were shown in Fig.2.The 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 improved significantly.6 Conclusion and outlook This 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.Many countries and research groups are doing research in the area.But it’s 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 motor Stepper motor is the electric pulse signals into angular displacement or linear displacement of the open-loop stepper motor control element pieces.In the case of 8 non-overloaded, the motor speed, stop position depends only on the pulse frequency and pulse number, regardle of load changes, when the driver receives a step pulse 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;the same time by controlling the pulse frequency to control the motor rotation speed and acceleration, to achieve speed control purposes.1 Work Induction 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, 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 conventional 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, electromechanical 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 Categories Now more commonly used 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 motor Permanent magnet stepper motor is generally two-phase, torque, and smaller, usually 7.5 degree step angle or 15 degrees;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 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.Hybrid Stepping Motor Hybrid Step Motor combines reactive, permanent magnet stepper motors of both, it's 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-phase: 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 saving 6 Three-phase stepper motor drive special features:  180% low torque output, low frequency characteristics of a good run  Maximum output frequency 600Hz, high-speed motor control  full range of detection of protection(over voltage, under voltage, overload)instantaneous power failure restart  acceleration, deceleration, such as dynamic change in the stall protection function to prevent  Electrical dynamic parameters of automatic recognition function to ensure stability and accuracy of the system  quick response and high-speed shutdown  abundant and flexible input and output interface and control, versatility  use of SMT production and three full-mount anti-paint treatment proce, product stability and high  full range of Siemens IGBT power devices using the latest, to ensure the quality of high-quality 7 Basic principles Usually 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 angle of the magnetic field makes the direction of a rotor and the stator's 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 forward.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 phase in order to control the stepper motor rotation.8 Induction Stepping Motor 8-1 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 field 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 operation, 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, 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 motor's internal winding consistent with the four-phase motors, small power motors are generally directly connected to the second phase, the power of larger 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 claification：Induction 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 are 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 neceary cyclical changes in a magnetic field pulses or conducting state with n said, or that 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 with θ said.θ = 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 θ = 360 ° /(50 * 4)= 1.8 degrees(commonly called the whole step), eight-shot running step angle θ = 360 ° /(50 * 8)= 0.9 degrees(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 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 air gap, increase the excitation ampere-turns to increase the static torque is not desirable, this will cause the motor heating and mechanical noise.12 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E的模糊集合为{NB NM NS NO PO PS PM PB};误差变化量Ec、参数Kp、Ki、Kd的模糊集合为{NB NM NS ZO PS PM PB}。他们表示的意义为：NB=负大、NM=负中、NS=负小、NO=负零、ZO=零、PO=正零、PS=正小、PM=正中、PB=正大。得到模糊变量E、EC、Kp、Ki、Kd的隶属度函数曲线如图3至图7所示：

图3 Kp隶属函数响应曲线

图4 Ki隶属函数响应曲线

图5 Kd隶属函数响应曲线

图6 E隶属函数响应曲线

图7 Ec隶属函数响应曲线

在模糊化完成后需要建立规则表，根据规则表的描述，可以总结出56个模糊条件语句，形式例如：如果(E 是 PB)并且(Ec 是 PB)那么(Kp 是 PB)(Ki 是 ZO)(Kd是 PB)。详见表1—表3。

最后一个步骤是去模糊化和建立查询表。在模糊控制中查询表应该嵌入到程序中。假设输入的值是固定的那么可以在表中查出相应的输出值。实际上，这可以节省许多计算时间并使控制简化。

表1 Kp规则表

表2 Ki规则表

表3 Kd规则表

5．实验结果分析

图8 PID控制响应曲线

图9 模糊PID控制响应曲线

实验利用了转向机构模型，它的仿真回路已经由图2给出。我们已经用MATLAB仿真出了一般PID控制算法和模糊PID控制算法，获得的响应曲线如图

8、图9所示。

实验结果表明，同一般得PID控制相比模糊控制的响应时间要短且没有超调的。系统的动态性能有了重大的提高。

6．总结和展望

这篇文章给出了一个控制智能小车的设计方案，并且通过实验从实际上很好的验证了这个方案。

无人驾驶智能小车是以计算机技术、模式识别以及智能控制技术的发展为基础的。许多国家和机构都在做这一方面的研究，但它是一个复杂的系统，它包含了许多方面的技术，所以任何一个技术的发展都是重要的，这可能成为智能车发展的瓶颈。

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步进电机

步进电机是将电脉冲信号转变为角位移或线位移的开环控制元步进电机件。在非超载的情况下，电机的转速、停止的位置只取决于脉冲信号的频率和脉冲数，而不受负载变化的影响，当步进驱动器接收到一个脉冲信号，它就驱动步进电机按设定的方向转动一个固定的角度，称为“步距角”，它的旋转是以固定的角度一步一步运行的。可以通过控制脉冲个数来控制角位移量，从而达到准确定位的目的；同时可以通过控制脉冲频率来控制电机转动的速度和加速度，从而达到调速的目的。工作原理

步进电机是一种感应电机，它的工作原理是利用电子电路，将直流电变成分时供电的，多相时序控制电流，用这种电流为步进电机供电，步进电机才能正常工作，驱动器就是为步进电机分时供电的，多相时序控制器

虽然步进电机已被广泛地应用，但步进电机并不能象普通的直流电机，交流电机在常规下使用。它必须由双环形脉冲信号、功率驱动电路等组成控制系统方可使用。因此用好步进电机却非易事，它涉及到机械、电机、电子及计算机等许多专业知识。步进电机作为执行元件，是机电一体化的关键产品之一, 广泛应用在各种自动化控制系统中。随着微电子和计算机技术的发展，步进电机的需求量与日俱增，在各个国民经济领域都有应用。分类

现在比较常用的步进电机包括反应式步进电机（VR）、永磁式步进电机（PM）、混合式步进电机（HB）和单相式步进电机等。永磁式步进电机

永磁式步进电机一般为两相，转矩和体积较小，步进角一般为7.5度 或15度； 永磁式步进电动机输出力矩大，动态性能好，但步距角大。反应式步进电机

反应式步进电机一般为三相，可实现大转矩输出，步进角一般为1.5度，但噪声和振动都很大。反应式步进电机的转子磁路由软磁材料制成，定子上有多相励磁绕组，利用磁导的变化产生转矩。

反应式步进电动机结构简单，生产成本低，步距角小；但动态性能差。混合式步进电机

混合式步进电动机综合了反应式、永磁式步进电动机两者的优点，它的步距角小，出力大，动态性能好，是目前性能最高的步进电动机。它有时也称作永磁感应子式步进电动机。它又分为两相和五相：两相步进角一般为1.8度而五相步进角一般为 0.72度。这种步进电机的应用最为广泛。变频器对步进电机的节能改造 三相步进电机专用变频器特点：

■低频转矩输出180%，低频运行特性良好 ■输出频率最大600Hz，可控制高速电机

■全方位的侦测保护功能(过压、欠压、过载)瞬间停电再起动■加速、减速、动转中失速防止等保护功能

■电机动态参数自动识别功能，保证系统的稳定性和精确性 ■高速停机时响应快

■丰富灵活的输入、输出接口和控制方式，通用性强 ■采用SMT全贴装生产及三防漆处理工艺，产品稳定度高 ■全系列采用最新西门子IGBT功率器件，确保品质的高质量 基本原理

通常电机的转子为永磁体，当电流流过定子绕组时，定子绕组产生一矢量磁场。该磁场会带动转子旋转一角度，使得转子的一对磁场方向与定子的磁场方向一致。当定子的矢量磁场旋转一个角度。转子也随着该磁场转一个角度。每输入一个电脉冲，电动机转动一个角度前进一步。它输出的角位移与输入的脉冲数成正比、转速与脉冲频率成正比。改变绕组通电的顺序，电机就会反转。所以可用控制脉冲数量、频率及电动机各相绕组的通电顺序来控制步进电机的转动。感应子式步进电机

1、特点： 感应子式与传统的反应式相比，结构上转子加有永磁体，以提供软磁材料的工作点，而定子激磁只需提供变化的磁场而不必提供磁材料工作点的耗能，因此该电机效率高，电流小，发热低。因永磁体的存在，该电机具有较强的反电势，其自身阻尼作用比较好，使其在运转过程中比较平稳、噪音低、低频振动小。感应子式某种程度上可以看作是低速同步的电机。一个四相电机可以作四相运行，也可以作二相运行。（必须采用双极电压驱动），而反应式电机则不能如此。例如：四相，八相运行（A-AB-B-BC-C-CD-D-DA-A）完全可以采用二相八拍运行方式.不难发现其条件为C=,D=.一个二相电机的内部绕组与四相电机完全一致，小功率电机一般直接接为二相，而功率大一点的电机，为了方便使用，灵活改变电机的动态特点，往往将其外部接线为八根引线（四相），这样使用时，既可以作四相电机使用，可以作二相电机绕组串联或并联使用。

2、分类

感应子式电机以相数可分为：二相电机、三相电机、四相电机、五相电机等。以机座号（电机外径）可分为：42BYG(BYG为感应子式步进电机代号）、57BYG、86BYG、110BYG、（国际标准），而像70BYG、90BYG、130BYG等均为国内标准。

3、步进电机的静态指标术语 相数：

产生不同对极N、S磁场的激磁线圈对数。常用m表示。拍数：完成一个磁场周期性变化所需脉冲数或导电状态用n表示，或指电机转过一个齿距角所需脉冲数，以四相电机为例，有四相四拍运行方式即AB-BC-CD-DA-AB，四相八拍运行方式即 A-AB-B-BC-C-CD-D-DA-A.步距角：对应一个脉冲信号，电机转子转过的角位移用θ 20 表示。θ=360度（转子齿数J*运行拍数），以常规二、四相，转子齿为50齿电机为例。四拍运行时步距角为θ=360度/（50*4）=1.8度（俗称整步），八拍运行时步距角为θ=360度/（50*8）=0.9度（俗称半步）。定位转矩：电机在不通电状态下，电机转子自身的锁定力矩（由磁场齿形的谐波以及机械误差造成的）静转矩：电机在额定静态电作用下，电机不作旋转运动时，电机转轴的锁定力矩。此力矩是衡量电机体积（几何尺寸）的标准，与驱动电压及驱动电源等无关。虽然静转矩与电磁激磁安匝数成正比，与定齿转子间的气隙有关，但过分采用减小气隙，增加激磁安匝来提高静力矩是不可取的，这样会造成电机的发热及机械噪音。