Subscriber整合

1. 添加subscriber创建

  1. self.subscriber = self.node.create_subscription(Pose, '/turtle1/pose', self.pose_call_back,10)

2. 添加订阅回调

  1. def pose_call_back(self, pose):
  2.     self.x_label.setText(str(pose.x))
  3.     self.y_label.setText(str(pose.y))
  4.     self.angle_label.setText(str(pose.theta))
  5.     self.linear_label.setText(str(pose.linear_velocity))
  6.     self.angular_label.setText(str(pose.angular_velocity))

3. 调试

t_2.png
为了能收到订阅的消息,需要定时的调用spin_once获取订阅收topic返回的消息:

  1. 定义定时器 ```python updateTimer = QTimer(self) updateTimer.setInterval(16) updateTimer.start()

updateTimer.timeout.connect(self.onUpdate)

  2. 2. 定时到之后,执行更新操作
  3. ```python
  4. def onUpdate(self):
  5.     self.update()
  6.     rclpy.spin_once(self.node)
  7.     if not rclpy.ok():
  8.         self.close()

注意: 需要调用update更新界面

完整示例代码

  1. import rclpy
  2. import sys
  3. from rclpy.node import Node
  4. from geometry_msgs.msg import Twist
  5. from turtlesim.msg import Pose
  6. from PyQt5.QtWidgets import QWidget, QApplication, QFormLayout, QLineEdit, QPushButton, QLabel
  7. from PyQt5.QtCore import QTimer
  10. class MainWindow(QWidget):
  11.     def __init__(self, node):
  12.         super(MainWindow, self).__init__()
  13.         self.node = node
  14.         # timer
  15.         updateTimer = QTimer(self)
  16.         updateTimer.setInterval(16)
  17.         updateTimer.start()
  19.         updateTimer.timeout.connect(self.onUpdate)
  20.         # topic
  21.         self.publisher = self.node.create_publisher(Twist, '/turtle1/cmd_vel', 10)
  22.         self.subscriber = self.node.create_subscription(Pose, '/turtle1/pose', self.pose_call_back,10)
  24.         self.resize(400, 120)
  25.         self.setWindowTitle('小乌龟控制')
  26.         # 布局
  27.         layout = QFormLayout()
  28.         self.setLayout(layout)
  30.         # 控件
  31.         self.editLinear = QLineEdit()
  32.         layout.addRow("线速度", self.editLinear)
  34.         self.editAngular = QLineEdit()
  35.         layout.addRow("角速度", self.editAngular)
  37.         # x
  38.         self.x_label = QLabel('0')
  39.         # y
  40.         self.y_label = QLabel('0')
  41.         # linear
  42.         self.linear_label = QLabel('0')
  43.         # angular
  44.         self.angular_label = QLabel('0')
  45.         # angle
  46.         self.angle_label = QLabel('0')
  47.         layout.addRow('x坐标', self.x_label)
  48.         layout.addRow('y坐标', self.y_label)
  49.         layout.addRow('线速度', self.linear_label)
  50.         layout.addRow('角速度', self.angular_label)
  51.         layout.addRow('角度', self.angle_label)
  53.         btnSend = QPushButton("发送")
  54.         layout.addRow('', btnSend)
  55.         btnSend.clicked.connect(self.start_control)
  57.     def start_control(self):
  58.         data = Twist()
  59.         data.linear.x = float(self.editLinear.text())
  60.         data.angular.z = float(self.editAngular.text())
  61.         self.publisher.publish(data)
  63.     def pose_call_back(self, pose):
  64.         self.x_label.setText(str(pose.x))
  65.         self.y_label.setText(str(pose.y))
  66.         self.angle_label.setText(str(pose.theta))
  67.         self.linear_label.setText(str(pose.linear_velocity))
  68.         self.angular_label.setText(str(pose.angular_velocity))
  70.     def onUpdate(self):
  71.         self.update()
  72.         rclpy.spin_once(self.node)
  73.         if not rclpy.ok():
  74.             self.close()
  78. def main():
  79.     rclpy.init()
  80.     node = Node('turtlesim_control')
  81.     app = QApplication(sys.argv)
  82.     window = MainWindow(node)
  83.     window.show()
  84.     # rclpy.spin(node)
  85.     result = app.exec_()
  86.     node.destroy_node()
  87.     rclpy.shutdown()
  88.     sys.exit()
  91. if __name__ == '__main__':
  92.     main()