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1. Install the package
sudo apt-get install ros-kinetic-rosbridge-suite
2. Use
1. Create a new html file
<!DOCTYPE html>
<html>
<head>
<meta charset="utf-8" />
<script type="text/javascript" src="http://static.robotwebtools.org/EventEmitter2/current/eventemitter2.min.js"></script>
<script type="text/javascript" src="http://static.robotwebtools.org/roslibjs/current/roslib.min.js"></script>
<script type="text/javascript" type="text/javascript">
// Connecting to ROS
var ros = new ROSLIB.Ros({
url : 'ws://localhost:9090'
});
//判断是否连接成功并输出相应的提示消息到web控制台
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.');
});
// Publishing a Topic
var cmdVel = new ROSLIB.Topic({
ros : ros,
name : '/cmd_vel',
messageType : 'geometry_msgs/Twist'
});//创建一个topic,它的名字是'/cmd_vel',,消息类型是'geometry_msgs/Twist'
var twist = new ROSLIB.Message({
linear : {
x : 0.1,
y : 0.2,
z : 0.3
},
angular : {
x : -0.1,
y : -0.2,
z : -0.3
}
});//创建一个message
function func()//在点击”Publish”按钮后发布消息，并对消息进行更改
{
cmdVel.publish(twist);//发布twist消息
twist.linear.x = twist.linear.x + 0.1;
twist.linear.y = twist.linear.y + 0.1;
twist.linear.z = twist.linear.z + 0.1;
twist.angular.x = twist.angular.x + 0.1;
twist.angular.y = twist.angular.y + 0.1;
twist.angular.z = twist.angular.z + 0.1;
}
// Subscribing to a Topic
var listener = new ROSLIB.Topic({
ros : ros,
name : '/chatter',
messageType : 'std_msgs/String'
});//创建一个topic,它的名字是'/chatter',,消息类型是'std_msgs/String'
function subscribe()//在点击”Subscribe”按钮后订阅'/chatter'的消息，并将其显示到网页中
{
listener.subscribe(function(message) {
document.getElementById("output").innerHTML = ('Received message on ' + listener.name + ': ' + message.data);
});
}
function unsubscribe()//在点击”Unsubscribe”按钮后取消订阅'/chatter'的消息
{
listener.unsubscribe();
}
</script>
</head>
<body>
<h1>Simple roslib Example</h1>
<p>Check your Web Console for output.</p>
<p id = "output"></p>
<button onclick = "func()">Publish</button>
<button onclick = "subscribe()">Subscribe</button>
<button onclick = "unsubscribe()">Unsubscribe</button><br />
</body>
</html>
2. Run
When using ROS Web, we must first run a launch file so that the Web terminal can connect to the ROS host and run in the terminal:
roslaunch rosbridge_server rosbridge_websocket.launch
Display:
Open a new terminal:
rosrun roscpp_tutorials talker
Open another terminal:
rostopic echo /cmd_vel
The purpose of this operation is to topics published by the talker node ‘/chatter’messages, facilitate this topic subscription operation in the Web side. Then open in the browser .htmlfiles, and open the Web console, will appear the following interface:
- F12 into the console
You can send and receive topics through the web
All topics at this time
seivl@seivl-Default-string:~$ rostopic list
/chatter
/client_count
/cmd_vel
/connected_clients
/rosout
/rosout_agg
Shut down the node, the console will also prompt to disconnect:
3. Reference
- Reference blog: Interaction between ros and web