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2017-08-11 06:38:48 -0500 answered a question how can i capture an image from camera using opencv c++ code in ROS ?

You should have a look at the UVC camera package or at the lib UVC camera package since I suppose you you are using a U

2017-08-08 02:21:21 -0500 answered a question stereo_calibration - rotation and translation matrix from output?!

By convention, the projection matrix has the following format : [fx' 0 cx' Tx] [ 0 fy' cy' Ty

2017-08-07 04:18:54 -0500 edited answer What is a better solution for controlling actuators than Arduino????

You can use rosserial_mbed. It is a client library similar to rosserial_arduino that will help you to easily interface y

2017-08-07 04:14:14 -0500 edited answer What is a better solution for controlling actuators than Arduino????

You can use rosserial_mbed. It is a client library similar to rosserial_arduino that will help you to easily interface y

2017-08-07 03:31:40 -0500 edited answer What is a better solution for controlling actuators than Arduino????

You can use rosserial_mbed. It is a client library similar to rosserial_arduino that will help you to easily interface y

2017-08-07 02:41:10 -0500 answered a question What is a better solution for controlling actuators than Arduino????

You can use rosserial_mbed). It is a client library similar to rosserial_arduino that will help you to easily interface

2017-07-31 08:22:28 -0500 marked best answer Fix subcriber rate and drop other messages

I have an IMU topic that is published at ~1kHz and I want my suscriber ton only process 1 message out of 50, discarding the other messages. Is there a c++ way to do this ?

I am aware of the throttle command but that's not what I am looking for.

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2017-07-31 01:46:52 -0500 commented answer Fix subcriber rate and drop other messages

Thanks Lucas for all these tests ! However some of your links are pointing to are not pointing to the right github page

2017-07-31 01:46:37 -0500 commented answer Fix subcriber rate and drop other messages

Thanks Lucas for all these tests ! However some of you links are pointing to are not pointing to the right github page (

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2017-07-27 03:17:28 -0500 commented answer Fix subcriber rate and drop other messages

The imu topic is published by a ros node that only serves as a bridge from a propretary library (used by several sensors

2017-07-27 03:05:11 -0500 commented answer Fix subcriber rate and drop other messages

Thanks for your answer. The problem is, I cannot lower the publishing rate and adding an intermediate node will increase

2017-07-27 01:40:26 -0500 commented answer Fix subcriber rate and drop other messages

Yeah obviously but the fact is that I need to save as much CPU as possible so I was looking for a solution that prevent

2017-07-27 01:39:56 -0500 commented answer Fix subcriber rate and drop other messages

Yeah obviouly but the fact is that I need to save as much CPU as possible so I was looking for a solution that prevent t

2017-07-26 06:58:15 -0500 asked a question Fix subcriber rate and drop other messages

Fix subcriber rate and drop other messages I have an IMU topic that is published at ~1kHz and I want my suscriber ton on

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2017-07-11 06:06:40 -0500 commented answer How to log ROS-messages?

This is a rosbag problem, just refer to this page or try to do another rosbag record

2017-07-11 04:29:48 -0500 commented answer how can I use sensor_msgs/BatteryState

Does it solve your problem ? If yes please accept the answer so others can also benefit

2017-07-10 09:22:46 -0500 commented answer how can I use sensor_msgs/BatteryState

You will find how to write a simple suscriber in python here. I don't know the name of your topic but I am pretty sure y

2017-07-10 09:22:36 -0500 commented answer how can I use sensor_msgs/BatteryState

You will find how o write a simple suscriber in python here. I don't know the name of your topic but I am pretty sure yo

2017-07-10 08:50:26 -0500 answered a question how can I use sensor_msgs/BatteryState

You can write a simple suscriber ( you can follow this tutorial ) that will suscribe to your battery state topic. In th

2017-07-07 01:30:41 -0500 marked best answer Conversion from 32FC1 to mono8 using cv_bridge

I am trying to use cv_bridge to convert an image from /disp_map/image (32FC1 encoding according to msg->encoding ) to an image usable in opencv with the following code :

void detectionCallback(const sensor_msgs::ImageConstPtr& msg) {
   cv_bridge::CvImagePtr cv_ptr;
   try
   {
     cv_ptr = cv_bridge::toCvCopy(msg, "mono8");
   }
    catch (cv_bridge::Exception& e)
   {
    ROS_ERROR("cv_bridge exception: %s", e.what());
    return;
   }
}

And i get the following error :

[ERROR] [1499238883.621456903]: cv_bridge exception: [32FC1] is not a color format. but [mono8] is. The conversion does not make sense

What's the best solution to solve this ?

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2017-07-06 07:47:16 -0500 commented answer Unable to show messages

you can add it to your .bashrc file

2017-07-06 07:45:26 -0500 commented question Stereo Camera Calibration

have you tried (without modifying your launch file): rosrun camera_calibration cameracalibrator.py --size 8x6 --square

2017-07-06 07:44:41 -0500 commented question Stereo Camera Calibration

have you tried : rosrun camera_calibration cameracalibrator.py --size 8x6 --square 0.108 --no-service-check right:=/cam

2017-07-06 07:43:41 -0500 commented question Stereo Camera Calibration

You should be able to add "--no-service-check" to camera calibration's parameters to skip the service checks. You'll hav

2017-07-06 07:40:21 -0500 commented question Stereo Camera Calibration

It looks like the service '/camera1/set_camera_info' is not available.

2017-07-06 07:36:20 -0500 commented answer How to log ROS-messages?

You can use rostopic echo -b file.bag -p /topic > data.txt as I explained before to export your data to a text file (

2017-07-06 06:13:11 -0500 commented question Stereo Camera Calibration

What are the services available (the result of rossrv list ) ?

2017-07-06 01:59:07 -0500 edited answer How to log ROS-messages?

You can use rosbags to save the data published in different topics (and play it later). You will find more informations

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2017-07-06 01:47:33 -0500 commented question vision_opencv install/build error

Which version of ROS are you using ?

2017-07-06 01:44:06 -0500 answered a question How to log ROS-messages?

You can use rosbags to save the data published in different topics (and play it later). You will find more informations

2017-07-05 08:01:49 -0500 edited answer Conversion from 32FC1 to mono8 using cv_bridge

I manage to make it works using opencv 3 (compiling cv_bridge from sources ) I had to add a few lines of code to conve

2017-07-05 08:01:06 -0500 answered a question Conversion from 32FC1 to mono8 using cv_bridge

I manage to make it works using opencv 3 (compiling cv_bridge from sources ) I had to add a few lines of code to conve

2017-07-05 04:26:33 -0500 asked a question Conversion from 32FC1 to mono8 using cv_bridge

Conversion from 32FC1 to mono8 using cv_bridge I am trying to use cv_bridge to convert an image from /disp_map/image (32

2017-06-28 09:51:37 -0500 edited answer Stereo Camera Calibration

The main problem here is that the calibration node is looking for a topic named "/camera1/set_camera_info" and your came

2017-06-28 09:47:14 -0500 answered a question Stereo Camera Calibration

The main problem here is that the calibration node is looking for a topic named "/camera1/set_camera_info" and your came

2016-07-19 04:29:13 -0500 edited answer Change publishing rate in source code

You can use ros::Rate where frequency is the desired frequency.

// Run at the configured rate, discarding msgs if necessary

ros::Rate rate(frequency);

//main loop

while (ros::ok())
  {
  ros::spinOnce();
  rate.sleep();

  if (std::abs((rate.expectedCycleTime() - ros::Duration(1.0 / frequency)).toSec()) > 0.001)
  {
      // Change rate dynamically; if must be above 0, as 0 will provoke a segfault on next spinOnce
      ROS_DEBUG("Changing frequency from %.2f to %.2f", 1.0 / rate.expectedCycleTime().toSec(), frequency);
      rate = ros::Rate(frequency);
  }

}