10 week HW (3) action programming : action server node

1. make package

 

2. make python file

import rclpy
 
# import ActionServer class to make actionserver
from rclpy.action import ActionServer
from rclpy.node import Node
 
# import Fibonacci interface type
from my_interface_example.action import Fibonacci
 
class FibonacciActionServer(Node):
 
    def __init__(self):
        # Initialize FibonacciActionServer class & make node name
        super().__init__('fibonacci_action_server')
        self._action_server = ActionServer(
            self,
            Fibonacci,
            'fibonacci',
            self.execute_callback)
 
    def execute_callback(self, goal_handle):
        self.get_logger().info('Executing goal...')
 
        sequence = [0, 1]
 
        for i in range(1, goal_handle.request.order):
            sequence.append(sequence[i] + sequence[i-1])
 
        # succeed() function indicates the goal was successful
        goal_handle.succeed()
 
        result = Fibonacci.Result()
 
        # return the requested Fibonacci sequence
        result.sequence = sequence
        return result
 
def main(args=None):
    rclpy.init(args=args)
 
    fibonacci_action_server = FibonacciActionServer()
 
    rclpy.spin(fibonacci_action_server)
 
if __name__ == '__main__':
    main()

---

---

 

3. play

python은 인터프리터 언어로 빌드가 필요없다.

 

현재까지의 코드는 피드백이 없는 상태

피드백을 위해서는 코드를 수정해야 한다.

 

4. add the feedback

[revise code]

import time
import rclpy
 
# import ActionServer class to make actionserver
from rclpy.action import ActionServer
from rclpy.node import Node
 
# import Fibonacci interface type
from my_interface_example.action import Fibonacci
 
class FibonacciActionServer(Node):
 
    def __init__(self):
        # Initialize FibonacciActionServer class & make node name
        super().__init__('fibonacci_action_server')
        self._action_server = ActionServer(
            self,
            Fibonacci,
            'fibonacci',
            self.execute_callback)
 
    def execute_callback(self, goal_handle):
        self.get_logger().info('Executing goal...')
 
        # Define the feedback
        feedback_msg = Fibonacci.Feedback()
        feedback_msg.partial_sequence = [0, 1]
 
        for i in range(1, goal_handle.request.order):
            feedback_msg.partial_sequence.append(
                feedback_msg.partial_sequence[i] + feedback_msg.partial_sequence[i-1])
            self.get_logger().info('Feedback: {0}'.format(feedback_msg.partial_sequence))
 
            # publish Feedback msg
            goal_handle.publish_feedback(feedback_msg)
            time.sleep(1)
 
        # succeed() function indicates the goal was successful
        goal_handle.succeed()
 
        result = Fibonacci.Result()
 
        # return the requested Fibonacci sequence
        result.sequence = feedback_msg.partial_sequence
        return result
 
def main(args=None):
    rclpy.init(args=args)
 
    fibonacci_action_server = FibonacciActionServer()
 
    rclpy.spin(fibonacci_action_server)
 
if __name__ == '__main__':
    main()

 

5. play

 

 

next time we will add action client code