无线视频监控系统中英文.docx

1、无线视频监控系统中英文英文资料及中文翻译Development of a multi-agent system for robot soccer game一、 IntroductionAs modern industrial society progresses, the needs for useful robots are growing. Especially, mobile robots are special issue that gradually expands its realm in industrial and studying topics. Researches on

2、mobile robots have been mainly concentrated on single mobile robot. But, the development of multi-agent system is strongly needed by the growth of complexity of tasks for robots to perform.The multi-agent systems have been studied by many researchersl-3. Generally, multi-agent system is defined as t

3、he system composed of more than 2 robots 4 and performs the given task by cooperation. The system has some different factors compared with single robot system. First, the environment for robots to confront is dynamic. In multi-agent system, the robots themselves constitute dynamic environment, becau

4、se each robot should recognize the other robots as moving obstacles. Many previous researches on mobile robots assume that the environment is static, even for the researches on single mobile robot5,6. Second, since the system performs given task by cooperation, it is necessary to make overall system

5、 plan forroles of robots. One of the obvious characteristics of the multi-agent system is cooperation - for example, 4-5 robots carry furniture 7. To cooperate one another, the changes of robots position must be predictable. There are some ways to know the robots position. For example, robots commun

6、icate their position one after another, or a supervisor detects robots position and transmits them to robots. It is related to communication problem. Third, each component of the system such as robots, a supervisor, sensors, communication equipment is well developed, because they influence the overa

7、ll system performance. Also, it is necessary to adopt appropriate architecture.Robot soccer is an interesting domain for studying the multi-agent system. The players must work together: It means a sort of cooperation. Also, they play the game in dynamic environment: predictable and unpredictable env

8、ironment - our robots and opponents robots, respectively. The main object is to put the ball in opponents goal as frequently as possible in presence of opponents robots which have the same task. So, according to a situation, our robots decide which action they take -defense or offense, how they work

9、 and so on. In this point, the system needs real-time sensing, quick decision making and fast behaviors. It is related to system architecture and algorithms. As described above , soccer game includes many characteristics of multi-agent system and is abundant in applying AI techniques.One of the adva

10、ntages of robot soccer game is direct comparison of different systems. Many robot soccer systems are gathered in some competitions. We participated in a Soccer robot competition in Taejon, Korea called MIROSOT96 8. MIROSOT makes some rules. The rules describe precise specification for soccer game. T

11、he playground is rectangular with its length 130cm, its width 90cm. An orange golf ball is selected as the play ball. The size of a robot is restricted within 7.5*7.5*7.5cm. One team consists of three robots. We purpose to make soccer system with three robots.In this paper, we explain some factors t

12、o be considered in establishing complete system. First, since the system architecture is very important, we decide the overall system as a centralized on-line system on the basis of surveys of multi-agent systems. Second, the overall system can be divided into three parts - A robot, communication an

13、d vision system. We describe the specifications of components of each part and the reasons to decide them. It would be helpful for later improvement.The rest of the paper is organized as follows. Section 2 gives some surveys of system architectures and selection of our soccer robot system. Section 3

14、 gives detailed descriptions of implemented hardware, especially mini robots. Section 4 gives cooperation and path plan algorithm for robot soccer game. Section 5 gives conclusion of this paper and presents further works.二、Categorization of multi-agent system and selection of soccer robot systemThe

15、survey on this issue is closely related in Arais work4. We can categorize multi- agent system based on two criteria. One is Who makes decision and orders? -Centralized / Decentralized , the other is When does the system make plans? - On line / Offline.Centralized system means that a supervisor integ

16、rates all available data, plans the behaviors of all the robots and makes commands. Since a supervisor considers all the robots simultaneously, the system can achieve the optimization of the motions of all the robots. But, as the number of robot increases, more computational power of a supervisor is

17、 needed. If the supervisor makes any fault, there is no way for the robots to correct it.Decentralized system means that each robot makes plan for itself on the basis of collected information from other robots and its own sensors. In the system, there is not considerable increasing computational loa

18、d as the number of robots increases. Even if one robot fails to work, other robots work well. But, the system cannot guarantee the optimization of the motions of all the robots.Off-line system means that all the paths are planned before all the robots move. Because of no restriction of time and comp

19、uting power, the system can achieve optimization. But, since the system assumes static environment, it is not robust to small variation of environment. In real world, it may malfunction with some variances.On-line system means real-time planning. It is robust to dynamic environment. But, it needs la

20、rge computational power and effective algorithm.In a lot of researches, the above two categorizations are interrelated each other. We summarize the researches in Table 1.Table 1. Categorization of multi-agent systemwhowhenproposed methodsCentralizedOff-linecell Decomposition Retraction10 Priority5,6

21、CentralizedOn-lineDecentralizedOff-linePriorityllDecentralizedOn-linePotential Field 12Rule-based13 Communication 14In MIROSOT96, The size of a robot is restricted. Therefore, it is difficult to implement a robot with large computational power. Also, it is important to decide what a robot must equip

22、. Basically, a robot has to equip actuator module and communication module. Additional equipments are selected and implemented considering the space of a robot. Soccer game needs global information of our robots position. So, we decide the centralized system as our system. From the viewpoint of path

23、 planning time, we decide the on-line system. Soccer game has fast changing nature and necessitates real-time sensing, fast behaviors, and quick decision making. It is reasonable to adopt on-line system. In centralized on-line system, a supervisor acquires all available information of whole environm

24、ent and the robots. Simultaneously, a supervisor should plan all the robots paths in real-time. Therefore it requires fast computing power. To decrease the burden of a supervisor, we choose partitioned system which separate main planning and executing. This is somewhat similar to the works of Shakey

25、15, Firby16. In our soccer robot system, a supervisor makes plans of all the robots on the basis of some strategy. Then, a supervisor transmits next desired position to each robot. Each robot receives desired position and executes its control algorithm for position and velocity controls. Simultaneou

26、sly, each robot takes data of its own local sensor which are fused with desired position into desired input of its own control loop. Therefore, a robot must possess some logic : a sort of a brain. So, our robots have micro-controllers. In this architecture, the system partitions computing burdens. F

27、igure 1 shows the functional diagram of our soccer robot system. Since a supervisor receives positions of the ball and all robots, the system doesnt need bi-directional communication. A supervisor only transmits commands to each robot. In the case of bi-directional communication, the logic of transm

28、itting and receiving order and priority must be needed. It may increase complexity of communication system of both a supervisor and a robot.Figure 1. The constitution of our soccer robot system三、System implementationSystem is composed of three parts - a supervisor, vision and 5 robots. A supervisor

29、is a PC - pentium processor -which makes plan in real time, and vision system has two cameras which have red and blue filter respectively, and image processing board which has a DSP and memory. A robot has a CPU, communication module, IR sensors, motors, etc. These three parts are related one anothe

30、r. Detailed descriptions are given in following chapters.1. Configuration of individual robotA robot is consisted of mechanical part, CPU board, communication(receiver module and sensor board. Its size is within 7.5*7.5*7.5 cm.2. Mechanical partMechanical part of a robot is consisted of two motors,

31、encoders, gearheads, wheels, a ball caster, and a frame. The frame is designed for easy, compact and hardy integration. Motors and gearheads are selected in consideration for operating voltage, internal resistance, mechanical time constant. Its operating voltage is 6V. Reduction ratio of gearhead is

32、 1:41. A diameter of a wheel is 32 mm. The no-load speed of a motor is 15200 rev/min. So, no-load speed of robots can be calculated as about 62 cm/sec. In real robots, we measure the maximum speed of a robot. The result is about 40cm/sec. Two motors are controlled by a CPU in main board independently. The encoder generates 16 pulses per revolution.3. CPU board and sensor boardFigure 2. The CPU board and sensor board(a)the locations of LEDs in CPU board forrobots position and rotation(b)the locations of IR sensors in sensor boardIn CPU board,