1 安装

参考官网安装步骤《Ubuntu（Debian） — ROS 2 文档：银河文档》

1.1 添加ROS2源

sudo curl -sSL https://raw.githubusercontent.com/ros/rosdistro/master/ros.key -o /usr/share/keyrings/ros-archive-keyring.gpg

echo "deb [arch=$(dpkg --print-architecture) signed-by=/usr/share/keyrings/ros-archive-keyring.gpg] http://packages.ros.org/ros2/ubuntu $(. /etc/os-release && echo $UBUNTU_CODENAME) main" | sudo tee /etc/apt/sources.list.d/ros2.list > /dev/null

1.2 更新源

sudo apt update

sudo apt upgrade

1.3 安装版本

如ubuntu20.04版本，选择galactic。

选择以下任意版本安装，若安装较慢，可将ubuntu源切换成国内源。

版本	安装命令
桌面安装（推荐）：ROS，RViz，演示，教程	sudo apt install ros-galactic-desktop
ROS 基本安装（裸骨）：通信库、消息包、命令行工具。没有图形用户界面工具。	sudo apt install ros-galactic-ros-base
开发工具：用于构建 ROS 包的编译器和其他工具	sudo apt install ros-dev-tools

1.4 将源添加到 shell 启动脚本中

echo "source /opt/ros/galactic/setup.bash" >> ~/.bashrc

1.5 检查环境变量

printenv | grep -i ROS

1.6 bridge-server

该服务可用于websocket服务通信

apt install ros-galactic-rosbridge-server

1.7 注意事项

1) 配置ros2源无法地址403时，

解决：手动配置域名映射185.199.108.133 raw.githubusercontent.com

2) 更换阿里云apt源，以20.04为例

mv /etc/apt/sources.list /etc/apt/sources.list_bak

vi /etc/apt/sources.list

deb https://mirrors.aliyun.com/ubuntu/ focal main restricted universe multiverse

deb-src https://mirrors.aliyun.com/ubuntu/ focal main restricted universe multiverse

deb https://mirrors.aliyun.com/ubuntu/ focal-security main restricted universe multiverse

deb-src https://mirrors.aliyun.com/ubuntu/ focal-security main restricted universe multiverse

deb https://mirrors.aliyun.com/ubuntu/ focal-updates main restricted universe multiverse

deb-src https://mirrors.aliyun.com/ubuntu/ focal-updates main restricted universe multiverse

# deb https://mirrors.aliyun.com/ubuntu/ focal-proposed main restricted universe multiverse

# deb-src https://mirrors.aliyun.com/ubuntu/ focal-proposed main restricted universe multiverse

deb https://mirrors.aliyun.com/ubuntu/ focal-backports main restricted universe multiverse

deb-src https://mirrors.aliyun.com/ubuntu/ focal-backports main restricted universe multiverse

2 使用

2.1 编译工具colcon安装

# 安装

sudo apt-get install python3-colcon-common-extensions

# 编译

colcon build --symlink-install

# 编译生成build/install/log文件夹，执行setup.bash使生效

source install/setup.bash

2.2 使用JAVA发布/订阅ROS2

相当于使用websocket进行消息通信，ros2需要启动rosbridge服务，java去订阅这个服务。

2.2.1 启动rosbridge_server服务

ros2 launch rosbridge_server rosbridge_websocket_launch.xml

2.2.2 Java订阅

maven依赖

<artifactId>jrosbridge</artifactId>

</dependency>

代码实现

import com.alibaba.fastjson.JSON;

import edu.wpi.rail.jrosbridge.Ros;

import edu.wpi.rail.jrosbridge.Topic;

import edu.wpi.rail.jrosbridge.handler.RosHandler;

import edu.wpi.rail.jrosbridge.messages.Message;

import lombok.extern.slf4j.Slf4j;

import org.springframework.scheduling.annotation.Scheduled;

import org.springframework.web.bind.annotation.RestController;

import team.iOceanPlus.PB.Target.PBTarget;

import team.iOceanPlus.PB.Target.PBTarget.Builder;

import javax.annotation.PostConstruct;

import javax.websocket.Session;

import java.util.HashMap;

import java.util.Map;

@Slf4j

@Component

public class RosSubscribe implements RosHandler {

//properties配置文件配置

//ros服务器ip

// @Value("${ros.ip}")

private String ip = "192.168.136.138";

//指定订阅的话题名称/类型

// @Value("${ros.topic.gnss.name}")

private String topicName = "our_topic";

// @Value("${ros.topic.gnss.type}")

private String msgType = "std_msgs/String";

Ros ros = null;

boolean connect = false;

/**

* ros服务器故障断开每隔五秒重连

@Scheduled(cron = "*/5 * * * * ?")

void reconnect() {

if (!connect) {

log.error("未连接服务！正在重连ros服务器！");

init();

}

@PostConstruct

void init() {

try {

ros = new Ros(ip);

connect = ros.connect();

if (connect) {

Topic topic = new Topic(ros, topicName, msgType);

Map<String,Object> msg = new HashMap<>();

msg.put("data","测试 publish");

Message message1 = new Message(JSON.toJSONString(msg), "std_msgs/String");

topic.publish(message1);

//开始订阅话题

topic.subscribe(message -> {

try {

Map maps = (Map) JSON.parse(message.toString()); //message即该话题的广播消息

System.out.println(maps);

} catch (Exception e) {

log.error(e.toString());

}

});

ros.addRosHandler(this); //监听器监听ros连接状态

}

} catch (Exception e) {

log.error("ros服务器连接错误:" + e.toString());

connect = false;

}

@Override

public void handleConnection(Session session) {

log.info("ros已连接：" + session.getId());

}

@Override

public void handleDisconnection(Session session) {

log.error("断开ros连接：" + session.getId());

connect = false;

}

@Override

public void handleError(Session session, Throwable t) {

log.error("ros连接失败：" + session.getId() + "-----失败原因：" + t.toString());

connect = false;

}

2.2.3 JAVA发布

import com.alibaba.fastjson.JSON;

import edu.wpi.rail.jrosbridge.Ros;

import edu.wpi.rail.jrosbridge.Topic;

import edu.wpi.rail.jrosbridge.handler.RosHandler;

import edu.wpi.rail.jrosbridge.messages.Message;

import lombok.extern.slf4j.Slf4j;

import org.springframework.beans.factory.annotation.Autowired;

import org.springframework.scheduling.annotation.Scheduled;

import org.springframework.stereotype.Component;

import team.iOceanPlus.PB.Target.PBTarget;

import team.iOceanPlus.PB.Target.PBTarget.Builder;

import javax.annotation.PostConstruct;

import javax.websocket.Session;

import java.util.HashMap;

import java.util.Map;

@Slf4j

@Component

public class RosPublish implements RosHandler {

//properties配置文件配置

//ros服务器ip

// @Value("${ros.ip}")

private String ip = "192.168.136.138";

//指定订阅的话题名称/类型

// @Value("${ros.topic.gnss.name}")

private String topicName = "our_topic";

// @Value("${ros.topic.gnss.type}")

private String msgType = "std_msgs/String";

Ros ros = null;

boolean connect = false;

/**

* ros服务器故障断开每隔五秒重连

@Scheduled(cron = "*/5 * * * * ?")

void reconnect() {

if (!connect) {

log.error("未连接服务！正在重连ros服务器！");

init();

}

@PostConstruct

void init() {

try {

ros = new Ros(ip);

connect = ros.connect();

if (connect) {

Topic topic = new Topic(ros, topicName, msgType);

// 测试发布

Map<String,Object> msg = new HashMap<>();

msg.put("data","测试 publish");

Message message1 = new Message(JSON.toJSONString(msg), "std_msgs/String");

topic.publish(message1);

ros.addRosHandler(this); //监听器监听ros连接状态

}

} catch (Exception e) {

log.error("ros服务器连接错误:" + e.toString());

connect = false;

}

@Override

public void handleConnection(Session session) {

log.info("ros已连接：" + session.getId());

}

@Override

public void handleDisconnection(Session session) {

log.error("断开ros连接：" + session.getId());

connect = false;

}

@Override

public void handleError(Session session, Throwable t) {

log.error("ros连接失败：" + session.getId() + "-----失败原因：" + t.toString());

connect = false;

}

消息使用protobuf编码

使用Base64对protobuf的二进制数组进行字符串编码。

PBTarget pbTarget = PBTarget.newBuilder().build();

// JAVA

String encodeStr = Base64.getEncoder().encodeToString(pbTarget.toByteArray());

byte[] bytes Base64.getDecoder().decode(encodeStr);

PBTarget pbTarget = PBTarget.parseFrom(bytes);

// JS

atob(base64编码)

2.3 使用Python发布/订阅ROS2

以下发布和订阅只适合ROS服务端和python程序部署在一起。如果跨服务器，请使用websocket。

2.3.1 发布

import rclpy

from rclpy.node import Node

from std_msgs.msg import String

#####这部分配置似乎可有可无#####

#创建工作空间：（在ros2_ws/src下执行）ros2 pkg create --build-type ament_python topic_rclpy --dependencies rclpy

#将文件放到工作空间下的topic_rclpy目录下的topic_rclpy文件夹下

#编译工作空间：colcon build

#运行：ros2 run topic_rclpy topic_publisher（无需执行）

###########

class DataPublisher(Node):

def __init__(self, name, topic_this):

super().__init__(name)

self.topic_this = topic_this

self.get_logger().info("%s节点启动!" % name)

self.command_publisher_ = self.create_publisher(String, topic_this, 10)

def publish_command(self, value):

msg = String()

msg.data = value

self.command_publisher_.publish(msg)

self.get_logger().info(f'向{self.topic_this}发布了消息：{msg.data}')

def main(args=None):

rclpy.init(args=args)

processor = DataPublisher('pubulisher',"command") # 创建数据处理节点

rclpy.spin(processor)

processor.destroy_node()

rclpy.shutdown()

2.3.2 订阅

原理：定义一个监听类

import rclpy

from rclpy.node import Node

from std_msgs.msg import String

class LISTENER(Node):

def __init__(self, name, topic):

# 初始化

super().__init__(name)

# 创建发布节点

self.subscriber = self.create_subscription(String, topic, self.receive_callback, 10)

self.get_logger().info("LISTENER: I'm listener %s, I subscribed topic %s" % (name, topic))

self.n_receive = 0

# 订阅器都是通过回调函数来实现对应功能，callback()内部完成对应实现

def receive_callback(self, msg):

self.n_receive += 1

self.get_logger().info("%d I heard %s" % (self.n_receive, msg.data))

def main():

# 初始化

rclpy.init()

# 创建订阅节点

node = LISTENER(name="listener_node", topic='our_topic')

# 死循环

rclpy.spin(node)

# 关闭

rclpy.shutdown()

2.3.3 Ros-bridge-server

通过roslibpy库连接ros-bridge-server服务，可以实现跨服务器对ROS的消息发布与订阅。

import base64

from time import sleep

import roslibpy

from roslibpy import Ros

import Target_pb2

'''

这是一个通过使用roslibpy库连接ros-bridge-server进行消息发布和订阅操作的例子。

使用时请填写实际的host和port端口

'''

# 消息发布

class Publisher:

client = None

def __init__(self, host: str, port: int):

self.client = roslibpy.Ros(host=host, port=port)

self.client.run()

def publish(self, topic: str, data: str):

if not self.client.is_connected:

raise "ros client is not connect."

rosTopic = roslibpy.Topic(self.client, topic, 'std_msgs/String')

msg = {

"data": data

}

rosTopic.publish(msg)

def close(self):

self.client.close()

# 消息订阅

class Listener:

client: Ros = None

def __init__(self, host: str, port: int):

self.client = Ros(host=host, port=port)

self.client.run()

def subscribe(self, topic: str, callback):

listener = roslibpy.Topic(self.client, topic, 'std_msgs/String')

# 回调

listener.subscribe(callback)

def close(self):

self.client.close()

def callbackFunc(message):

# print('Heard talking: ' + message['data'])

body = base64.b64decode(message['data'])

pbTarget = Target_pb2.PBTarget()

pbTarget.ParseFromString(body)

print(pbTarget)

if __name__ == '__main__':

listener = Listener(host="localhost", port=9090)

listener.subscribe("/OnLineTruthTargetTracks", callbackFunc)

publisher = Publisher(host=" localhost", port=9090)

pbTarget = Target_pb2.PBTarget()

for num in range(100):

pbTarget.enum_Sender_Software = num

# 序列化并转为base64字符串

data = base64.b64encode(pbTarget.SerializeToString()).decode("UTF-8")

publisher.publish("/OnLineTruthTargetTracks", data)

# 消息发送太快可能会丢失

sleep(0.0001)

try:

while True:

pass

except KeyboardInterrupt:

listener.client.terminate()

publisher.client.terminate()

2.3.4 注意事项

2.3.4.1 导入rclpy依赖缺失

在python项目（非服务方式）中，通常使用pip install rclpy 或者conda来安装管理依赖，由于在pipy源中找不到该依赖。所以，可从ros2的安装目录下找到对应的依赖文件，操作步骤如下：

1、确认ros版本，如：galactic

2、临时生效：export PYTHONPATH=/opt/ros/galactic/lib/python3.8/site-packages

3、永久生效：echo “export PYTHONPATH=/opt/ros/galactic/lib/python3.8/site-packages” >> ~/.bashrc && source ~/.bashrc

3 参考资料

1) Ubuntu（Debian） — ROS 2 文档：银河文档

2) GitHub - h2r/java_rosbridge：一个简单的库，使用Jetty 9将Java连接到rosbridge服务器。支持使用不同的主题委托发布和订阅

3) java--Rosbridge--ros通信（基于webscoket）

4) ROS2前置基础教程| Python依赖查找流程

5) gramaziokohler/roslibpy: Python ROS Bridge library (github.com)

ROS2通讯中间件安装与使用

1 安装

1.1 添加ROS2源

1.2 更新源

1.3 安装版本

1.4 将源添加到 shell 启动脚本中

1.5 检查环境变量

1.6 bridge-server

1.7 注意事项

2 使用

2.1 编译工具colcon安装

2.2 使用JAVA发布/订阅ROS2

2.2.1 启动rosbridge_server服务

2.2.2 Java订阅

2.2.3 JAVA发布

消息使用protobuf编码

2.3 使用Python发布/订阅ROS2

2.3.1 发布

2.3.2 订阅

2.3.3 Ros-bridge-server

2.3.4 注意事项

2.3.4.1 导入rclpy依赖缺失

3 参考资料

热门文章

最新文章

相关课程

相关电子书

相关实验场景

推荐镜像