[coordinate_publisher-6] [INFO] [1737204129.386587739] [coordinate_publisher]: Time to fetch coordinates: 0.0201s
[publishCoords2audio-7] [INFO] [1737204129.391599837] [ambisonics_sound_node]: Published audio with azimuth: 136.29, elevation: 97.91
[coordinate_publisher-6] [INFO] [1737204129.409960361] [coordinate_publisher]: Time to fetch coordinates: 0.0216s
[coordinate_publisher-6] [INFO] [1737204129.435476604] [coordinate_publisher]: Time to fetch coordinates: 0.0240s
[coordinate_publisher-6] [INFO] [1737204129.458264791] [coordinate_publisher]: Time to fetch coordinates: 0.0212s
[coordinate_publisher-6] [INFO] [1737204129.481453334] [coordinate_publisher]: Time to fetch coordinates: 0.0217s
[publishCoords2audio-7] [INFO] [1737204129.491790249] [ambisonics_sound_node]: Published audio with azimuth: 137.41, elevation: 97.52
[coordinate_publisher-6] [INFO] [1737204129.506789359] [coordinate_publisher]: Time to fetch coordinates: 0.0241s
[angles_publisher-5] [WARN] [1737204129.546469382] [angles_publisher]: Relative RPY is not available or invalid
[coordinate_publisher-6] [INFO] [1737204129.546551160] [coordinate_publisher]: Time to fetch coordinates: 0.0376s
[coordinate_publisher-6] [INFO] [1737204129.587112946] [coordinate_publisher]: Time to fetch coordinates: 0.0376s
[publishCoords2audio-7] [INFO] [1737204129.595711244] [ambisonics_sound_node]: Published audio with azimuth: 137.88, elevation: 96.51
[coordinate_publisher-6] [INFO] [1737204129.613406799] [coordinate_publisher]: Time to fetch coordinates: 0.0236s
It seems that the time for the robot to fetch coordinates is long?
ChatGPT said:
ChatGPT
Yes, the log messages indicate that the time to fetch coordinates from the robotic arm varies, often exceeding 20 ms and occasionally reaching 37 ms or more. This is indeed a significant contributor to the latency in your system, especially since the publishing rate is intended to be 50 Hz (one message every 20 ms). When the coordinate fetching takes longer than 20 ms, it directly impacts the ability to publish coordinates on time, creating lag in the perceived sound position.
Why the Fetching Time is Long
Communication Overhead with the Robot:
Fetching coordinates involves TCP/IP communication with the robotic arm (MyCobotSocket). This process includes:
Sending a command to the robot.
Waiting for a response.
Processing the response.
Any delay in the network or on the robot's side will add to the fetching time.
Robot Response Time:
The robot itself may take time to compute and send back the requested coordinates, especially if it is under load or if the API implementation on the robot is inefficient.
Blocking Calls:
The mc.get_coords() method appears to be a blocking call, meaning your code waits for the robot's response before continuing. This contributes to the variability in fetching time.
How to Address This
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Optimize the Coordinate Fetching Process
Batch Requests:
If possible, configure the robot to send continuous updates for its coordinates, rather than requiring repeated requests. For example, if the robot supports streaming its position at a fixed rate, use that instead of polling (mc.get_coords).
Check the MyCobotSocket API documentation to see if a streaming mode is available.Asynchronous Fetching:
Use a non-blocking or asynchronous method to fetch coordinates. For example:import threading class CoordinatePublisher(Node): def __init__(self): super().__init__('coordinate_publisher') self.publisher_ = self.create_publisher(Float32MultiArray, '/robot_arm/coordinates', 10) self.timer = self.create_timer(0.02, self.publish_coordinates) self.tcp_ip = '192.168.62.179' self.tcp_port = 9001 self.mc = None self.latest_coords = None self.lock = threading.Lock() self.connect_to_robot_arm() # Start a background thread to fetch coordinates self.fetch_thread = threading.Thread(target=self.fetch_coordinates_loop) self.fetch_thread.daemon = True self.fetch_thread.start() def fetch_coordinates_loop(self): """Continuously fetch coordinates in the background.""" while rclpy.ok(): if self.mc: try: coords = self.mc.get_coords() with self.lock: self.latest_coords = coords except Exception as e: self.get_logger().error(f"Error fetching coordinates: {e}") self.mc = None self.connect_to_robot_arm() def publish_coordinates(self): """Publish the most recent coordinates.""" if self.latest_coords is None: self.get_logger().warning("No coordinates available yet.") return with self.lock: coords = self.latest_coords if coords and len(coords) == 6: msg = Float32MultiArray() msg.data = coords self.publisher_.publish(msg) self.get_logger().debug(f"Published coordinates: {coords}") -
Log Fetching Variability
Log both the individual fetching times and the variability (e.g., standard deviation or range) over time to monitor improvements.
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Increase Publishing Timer Interval (Temporarily)
If the coordinate fetching cannot be optimized immediately, you can increase the timer interval in the CoordinatePublisher node to match the fetching time (e.g., 30–40 ms). While this reduces the publishing frequency, it ensures consistent updates.
Next Steps
Investigate the Robot’s Capabilities:
Check if the robot supports streaming its coordinates rather than requiring polling.
If not, try optimizing the polling mechanism with asynchronous fetching as shown above.
Profile and Optimize:
Measure the time spent in each step of mc.get_coords() to identify specific bottlenecks (e.g., network latency, robot processing time).
Test the Asynchronous Solution:
Implement and test the asynchronous fetching solution to see if it reduces delays.
Let me know if you’d like me to integrate the asynchronous solution into your coordinate_publisher.py file for immediate testing!
标签：publisher,get,20ms,coordinates,fetch,coords,coordinate,self From： https://www.cnblogs.com/zhengshufang/p/18679722