应用AVR开发智能移动机器人的控制系统 - 图文-

1、文章编号:1007-757X(20106-0001-03应用A VR开发智能移动机器人的控制系统杨进摘 要:基于A VR系列的8位单片机,采用嵌入式分层控制方法,完成智能移动机器人的控制系统的开发。在该系统中,包括信息管理层和分散控制层。主机在信息管理层,完成传感器等信息及控制指令的处理;从机在分散控制层,完成电机的伺服控制。与基于51系列单片机开发的控制系统相比,本系统所需的外围电路更简单,数据处理速度更快。实验表明,该系统运行稳定,机器人移动平稳。该设计方案尤其适用智能移动机器人的开发,还可以广泛应用于其它智能设备和生产线的开发。关键词:机器人;控制系统;A VR;传感器中图分类号:TP2

2、42文献标志码:A左侧微处并调图1 机器人控制系统的结构图右侧结构图为伺服控制层,存在一个速度控制环。伺服控制系统的执行元件为直流旋转电机,系统的控制量是电机的转速。反馈元件采用旋转式光电编码器,反馈信号为光电编码器的脉冲信号(A、B两相。以ATmega8L微处理器作为计算控制单元,并在程序中设定速度采样频率为赫兹在每个采样周期内,微处理器计数编码器反馈的脉冲数。通过比较、B两相脉冲状态的变化并计数脉冲数,得到实时的速度值,再与目标速度数据比较,经过离散调解器计算,求得对电机的控制字。该控制字将修改单片机输,男,广州铁路职业技术学院,机电工程系,硕士,助教,研究方向:机器人设计理论与应用,广东

3、广州 510430·1··2·出的PWM 信号的占空比值,并通过OC1A 和OC1B 输出两路PWM 信号。经过对应的两路H桥驱动电路放大后,改变了两路电机的电枢电压有效值,从而实现速度的闭环控制。2 控制电路图2为信息管理层的控制电路。其中,系统供电为12伏直流电源,12伏电压是作为电机的驱动电压,也是光电开关的额定工作电压。通过3端稳压块LM7805获得稳定的5伏电压,为ATmega8L 微处理器提供额定的工作电压。ATmega8L 微处理器使用8M 赫兹晶振作为时钟源,采用上电复位方式。为作为控制核心的ATmega8L 微处理器,通过PC0PC3口

4、接收光电开关的开关信号6,获得障碍物的信息;通过ADC4、ADC5引脚接收光纤放大器反馈的模拟量信号,并转换成数字量,从而获得轨迹的信息;通过PB0、PB1和PC2PC7八个I/O 口接收遥控模块传递下来的控制指令。并且,主微处理器通过RXD 、TXD 引脚和伺服控制层的从机实现串行通信,向伺服控制层发送电机速度目标值,接收伺服控制层返回的电机运行实时情况。另外,电路中设计有ISP 接口,可以使用通用的A VR ISP 编程器很方便地下载程序。 图2 信息管理层的控制电路3 智能寻迹控制本文所开发的机器人,可以自动寻找由特定颜色所描绘的轨迹。在控制电路中,两个光纤放大器分别反馈一个模拟量信号,

5、并转换成数字量。单次转换的结果如下:REF IN V V ADC 1024×= (1式中,VIN 为被选中引脚的输入电压,VREF 为参考电压。0x000代表模拟地电平,0x3FF 代表所选参考电压的数值减去1LSB 7。电路中设计为ADC6和ADC7单端输入,通过微处理器内部定时/计数器0设定1毫秒的采样时间,每隔一个采样周期采集一路的信息。程序中首先需要T0和ADC 做相应的初始化。具体程序及注释如下。1. T/C0 初始化:TCCR0=0x0B; /内部时钟,64分频,CTC 模式 TCNT0=0x00;OCR0=0x7C;/ (124+1/125=1ms TIMSK=0x02

6、;/ 允许T/C0 比较中断 2. ADC 初始化程序:ADMUX=0x46;/ 参考电源A Vcc 、ADC6单端输入 SFIOR&=0x1F;SFIOR|=0x60; /选择T/C0 比较匹配中断为ADC 触发源ADCSRA=0xA9; /ADC 允许、自动触发转换、ADC 转换中断允许、ADCclk=2MHz#asm("sei" / 开放全局中断图3 定时器0比较中断子程序流程图定时/计数器0采用CTC 工作模式,通过比较中断准确定时1ms 。其比较中断子程序完成光纤放大器信号的读取和最初的数据处理任务。在CTC 工作模式下,当计数器0的数值TCNT0等于OC

7、R0(值为0x7C 时计数器自动清零。这个模式使得用户很容易地控制比较匹配输出的频率,也简化了外部事件计数的操作。在定时器0比较中断子程序中,轨迹的信息已被整理为TRACK 变量的数值,其有效数据为TRACK 的最低两位。当主程序初始化TRACK 为0x00后,轨迹的信息只有四个数据,分别是:0x00、0x01、0x02、0x03。其中0x01和0x02为刚刚偏离轨迹,0x01为左侧偏离,0x02为右侧偏离。数值0x03则表示机器人运行在轨迹上。而数值0x00所代表的运行状态就不是那么直接能判断的,需要和上一个采样周期的状态进行比较,才能得出结论。在自动寻迹子程序中还定义了一个静态变量OLD_

8、TRACK ,用于保存上一个采样周期的状态。当OLD_TRACK 为0x01时,则当前的TRACK (0x00表示严重偏离轨迹的左侧;当OLD_TRACK 为0x02时,则当前的TRACK (0x00表示严重偏离轨迹的右侧。·3·在自动寻迹子程序中,通过对TRACK 变量的数值进行逻辑判断,从而确定机器人相对轨迹的方向,并输出响应的速度控制量给伺服控制层。如上面程序流程图所示,当TRACK 发生变化时,输出也将改变。如果偏出轨迹左侧,则控制电机使机器人右转;如果偏出轨迹右侧,则控制电机使机器人左转;没有偏出,则以设定好的速度前进。 图4 自动寻迹子程序流程图4 实验按电路图

9、完成系统控制电路的制作。如图5所示,机器人通过车载蓄电池供电,由两块控制电路板控制,一块为按图2所设计的信息控制电路,另一块为伺服控制电路。使用WinA VR 软件按流程图编写好程序后,通过ISP 下载线将机器码,分别下载到两个ATmega8L 微处理器中。在图5中,a 图为机器人自动沿黄色描绘的迹线运动,b 图为机器人自动沿着墙体运行。 (a 机器人自动寻迹运动 (b 机器人自动沿墙体运行 图5 机器人自动运行5 结论本文基于A VR 微控制器开发出一台智能移动机器人,实验结果显示,机器人能够可靠地自动避开障碍物并找到自己运行的目标。通过伺服驱动,机器人能平稳较快速地前行。本文中的机器人,具

10、有清晰的控制系统结构,而且开发的成本低廉,所以该机器人的技术,尤其适用开发自动化教学设备。同时,该机器人技术,还可以广泛应用于自动设备的开发。参考文献1 徐国华,谭民.移动机器人的发展现状及其趋势J.机器人技术与应用, 2001(3: 7-14.2 徐玉,韩波,李平.基于A VR 的舵机控制器设计J.工业控制计算机, 2004(11:38-40. Xu Yu,Han Bo,Li Ping,The Design of A VR Based Servo ControllerJ, Industrial Control Computer, 2004(11:38-40.3 ATmega8芯片数据官方手册

11、M. ATmega8 Datasheet4 马潮,詹卫前,耿德根. ATmega8原理及应用手册M.第5版,北京:清华大学出版社, 2003:7-85 韩大鹏,韦庆.机器人控制器的一种模块化设计方法J.微计算机信息,2005(5:3-4.Han Da Peng,Wei Qing,A Design Method Via Modularization for Controllers of Mobile RobotsJ, Microcomputer Information, 2005(5: 3-4.6 阎石.数字电子技术基础(第四版,高等教育出版社,1998.117 沈文,Eagla lee,詹卫前

12、. A VR 单片机C 语言开发入门指导M.北京:清华出版社,2003.(收稿日期:2009-12-23ISSN1007-757X Zhu ZhongyingMicrocomputer Applications Editor-in-ChiefV ol.26, No.6 (General No.206Monthly (Since 1985 June 2010CONTENTSRESEARCH AND DESIGNDevelopment for Intelligent Mobile Robot Control System with A VR (1YANG Jin(Department of Ele

13、ctromechanical Engineering, Guangzhou Institute of Railway Technology, Guangzhou 510430, China Abstract: Based on 8-bit A VR series MCU, the control system of an intelligent mobile robot is completed by the method of embedded hierarchical control. There are two layers in the system, including inform

14、ation management and distributed control. The host MCU in the information management layer completes the processing of control commands and information such as the sensors. The slave MCU in the distributed control layer completes servo motor control. Compared to the control system development based

15、on the 51 Series MCU, the system has these advantages of simpler peripheral circuit and faster data processing. The experiments demonstrate that the mobile robot runs stably and smoothly by the control of A VR units, and that the design proposal especially benefits the development of intelligent mob

16、ile robots, also can be widely used in the development of other smart devices and product lines.Key words: Robot; Control System; A VR; SensorDesign of Wireless Communication System for Multi-Robots Based on 802.15.4 (4Zang Shenjun (Department of Computer Science and Engineering, Shanghai Jiaotong U

17、niversity, Shanghai 200240, ChinaAbstract: In this paper, a wireless communication system is designed and implemented for multi-robot system. Physical layer (PHY is designed, medium access control layer (MAC, network layer and interaction layer according to IEEE 802.15.4 standard which is establishe

18、d for Low-Rate Personal Area Network. Dynamic source routing (DSR algorithm is applied in network layer. Finally, the system is tested and analyzed on CC2430.Key words: 802.15.4; Wireless Networks; CC2430; DSRReal Time Facial Expression Recognition Based on SVM (8Zhang Peng, Jia Yinshan ,Liu Peishen

19、g(School of Computer and Communication Engineering ,Liaoning University of Petroleum and Chemical Technology , Fushun 113001, ChinaAbstract: Enabling computer systems to recognize facial expressions and infer emotions from them in real time presents a challenging research topic. In this paper, real

20、time approach to recognize facial expression is present in live video.We employ ASM method and an improved L-K optical flow algorithm to perform face localization and feature tracker.The facial feature displacements are used as input to a Support Vector Machine classifier. Our experiments demonstrat

21、e the effectiveness of a support vector machine and feature tracking approach to facial expressions recognition.Key words: Facial Expression; Support Vector Machines; Feature Tracking; Feature Displacements.Research on Accurate Modeling and Simulation of Physical Layer of Wireless Network (11ZHANG R

22、ui, LI Bo (School of Electronics and Information, Northwestern Polytechnical University, Xian 710129, ChinaAbstract: In wireless network simulation, the accuracy of the simulation for higher layer communication protocols heavily depends on the quality of PHY layer (physical layer modeling and simula

23、tion. However, the precision of OPNET modeling doesnt meet the need of wireless network simulation. In order to model and simulate the fundamentals of PHY layer accurately, the adverse effect upon the simulation accuracy is analyzed, which is deriving from the inward deficiencies of the original OPN

24、ET PHY layer simulation mechanism, such as inauthenticity of wireless channel and inaccuracy of transceiver working. Moreover, combining the fundamentals of PHY layer, an effective improved method to make up insufficiencies cased by OPNET modeling mechanism is proposed. This method optimizes the way

25、s of modeling the wireless channel, transceiver mechanism, calculation of frame-error rate (FER, and so on. Indicated from the simulation results, the innovated method for PHY layer modeling and simulation is able to remarkably improve the accuracy of the OPNET pipeline stage simulation mechanism.Ke

26、y words: Wireless Networkl; PHY Layer; Network SimulationResearch and Development on Figure Hospital Simulation Based on Medical Information (14Zhang Dan, Shen Xiaoping (School of Health Science and Nursing, Shanghai Sipo Polytechnic, Shanghai 201300, ChinaAbstract: In this paper, the function of th

27、e informational laboratory is investigated, the subject-designing-requirement and the system-designing of information-base experiment teaching and the management of the laboratory,etc.It training national medical information education base that co-hold to National medical information education manag

28、ement center of department of health and school of health science and nursing of shanghai sipo polytechnic.it trains a base and build a informationize management system.A “hospital simulating digitization”again on the basis of all-round informationizes administration medical education training base

29、will build and introduce.Key words: Informational Education; Educational Technology; Hygiene Information; Medical Physics; Digitize HospitalRealization and Security Design of Graduation Project Management System Based on ASP (17ZHAO Ling (Department of Information and Control, Xian Institute of Post Telecom, Xi an 710061, ChinaAbstract: Graduation project is a very important teaching p