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ROS与javascript入门教程-roslibjs-编写actionlib客户端

ROS1/一代机器人系统 少儿编程 1726浏览 0评论
ROS与JS入门教程

ROS与javascript入门教程-roslibjs-编写actionlib客户端

说明:

  • 介绍如何利用roslibjs编写actionlib客户端

github:

  • 参考代码库

参考代码:

  • 新建名称为fibonacci.html

  • 内容为:

<!DOCTYPE html>
<html>
<head>
<meta charset="utf-8" />
<script type="text/javascript" src="http://cdn.robotwebtools.org/EventEmitter2/current/eventemitter2.js"></script>
<script type="text/javascript" src="http://cdn.robotwebtools.org/roslibjs/current/roslib.js"></script>

<script type="text/javascript" type="text/javascript">
  var ros = new ROSLIB.Ros({
    url : 'ws://localhost:9090'
  });

  var fibonacciClient = new ROSLIB.ActionClient({
    ros : ros,
    serverName : '/fibonacci',
    actionName : 'actionlib_tutorials/FibonacciAction'
  });

  var goal = new ROSLIB.Goal({
    actionClient : fibonacciClient,
    goalMessage : {
      order : 7
    }
  });

  goal.on('feedback', function(feedback) {
    console.log('Feedback: ' + feedback.sequence);
  });

  goal.on('result', function(result) {
    console.log('Final Result: ' + result.sequence);
  });

  ros.on('connection', function() {
    console.log('Connected to websocket server.');
  });

  ros.on('error', function(error) {
    console.log('Error connecting to websocket server: ', error);
  });

  ros.on('close', function() {
    console.log('Connection to websocket server closed.');
  });

  goal.send();
</script>
</head>

<body>
  <h1>Fibonacci ActionClient Example</h1>
  <p>Check the Web Console for output</p>
</body>
</html>

代码解释:

  • 代码段:
  var fibonacciClient = new ROSLIB.ActionClient({
    ros : ros,
    serverName : '/fibonacci',
    actionName : 'actionlib_tutorials/FibonacciAction'
  });
  • 解释:

    • ROSLIB.ActionClient 作为actionlib客户端,发送一个目标到actionlib服务器端并获取一个反馈。
    • 更多ROSLIB.ActionClient文档参考:http://robotwebtools.org/jsdoc/roslibjs/current/ActionClient.html
  • 代码段:

  var goal = new ROSLIB.Goal({
    actionClient : fibonacciClient,
    goalMessage : {
      order : 7
    }
  });
  • 解释:
    • ROSLIB.Goal是一个actionlib目标,用于发送到actionlib服务器端
    • 更多ROSLIB.Goal文档参考:http://robotwebtools.org/jsdoc/roslibjs/current/Goal.html
  • 代码段:
  goal.on('feedback', function(feedback) {
    console.log('Feedback: ' + feedback.sequence);
  });

  goal.on('result', function(result) {
    console.log('Final Result: ' + result.sequence);
  });

  goal.send();
  • 解释:

    • 回调函数获取feedback和result的信息

运行:

  • 服务器端,新终端,运行:
roslaunch rosbridge_server rosbridge_websocket.launch
  • 服务器端,新终端,运行:
rosrun actionlib_tutorials fibonacci_server
  • 直接拖动文件到chrome浏览器
file://simple.html
  • 效果图:

参考:

  • http://wiki.ros.org/roslibjs/Tutorials/ActionlibClient

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