Ask Your Question

BhanuKiran.Chaluvadi's profile - activity

2019-10-11 07:38:32 -0500 received badge  Famous Question (source)
2019-09-02 15:07:21 -0500 commented answer Control System loop rate using CAN Communication

Actually, we are trying to synchronize positions of two joints but the control loop is so slow (20 Hz) it is giving us a

2019-09-02 15:05:03 -0500 commented question Control System loop rate using CAN Communication

Hi @duck-development , Currently, we are not using any rt Linux at one stage we tried using Apollo rt-kernel but the im

2019-09-02 13:30:24 -0500 received badge  Popular Question (source)
2019-09-02 01:49:26 -0500 edited question Control System loop rate using CAN Communication

Control System loop rate Hi, We have 9 joints in our robot and following ROS control - joint_velocity_controller and

2019-09-02 01:47:24 -0500 asked a question Control System loop rate using CAN Communication

Control System loop rate Hi, We have 9 joints in our robot and following ROS control - joint_velocity_controller and

2019-08-20 03:17:22 -0500 received badge  Popular Question (source)
2019-08-19 21:13:56 -0500 received badge  Notable Question (source)
2019-08-19 21:13:56 -0500 received badge  Popular Question (source)
2019-08-16 06:25:29 -0500 edited question Set Joint state publisher offsets

Set Joint state publisher offsets Hi , I have a physical robot that can increase and decrease in size. Whenever i boot

2019-08-16 04:59:47 -0500 asked a question Set Joint state publisher offsets

Set Joint state publisher offsets Hi , I have a physical robot that can increase and decrease in size. Whenever i boot

2019-08-07 11:34:08 -0500 received badge  Famous Question (source)
2019-07-14 06:24:42 -0500 received badge  Notable Question (source)
2019-06-29 11:44:23 -0500 received badge  Popular Question (source)
2019-06-26 16:53:32 -0500 commented question updateConfig() called on a dynamic_reconfigure::Server that provides its own mutex

Any solution ?

2019-06-26 15:14:03 -0500 received badge  Popular Question (source)
2019-06-25 07:25:43 -0500 edited question Unable to move robot inside gazebo.

Unable to move robot inside gazebo. Hi Guys, I am trying to move my robot inside gazebo. It spawns correctly inside th

2019-06-25 07:14:02 -0500 commented question Unable to move robot inside gazebo.

Can you open the question now ?

2019-06-25 06:51:17 -0500 edited question Unable to move robot inside gazebo.

Unable to move robot inside gazebo. Hi Guys, I am trying to move my robot inside gazebo. It spawns correctly inside th

2019-06-25 06:49:56 -0500 edited question Unable to move robot inside gazebo.

Unable to move robot inside gazebo. Hi Guys, I am trying to move my robot inside gazebo. It spawns correctly inside th

2019-06-25 06:26:14 -0500 edited question Unable to move robot inside gazebo.

Unable to move robot inside gazebo. Hi Guys, I am trying to move my robot inside gazebo. It spawns correctly inside th

2019-06-25 06:25:27 -0500 commented question Unable to move robot inside gazebo.

Edited. I think having a screenshot will eliminate thinking of obvious errors.

2019-06-25 06:23:15 -0500 edited question Unable to move robot inside gazebo.

Unable to move robot inside gazebo. Hi Guys, I am trying to move my robot inside gazebo. It spawns correctly inside th

2019-06-25 06:21:34 -0500 edited question Unable to move robot inside gazebo.

Unable to move robot inside gazebo. Hi Guys, I am trying to move my robot inside gazebo. It spawns correctly inside th

2019-06-25 06:14:18 -0500 asked a question Unable to move robot inside gazebo.

Unable to move robot inside gazebo. Hi Guys, I am trying to move my robot inside gazebo. It spawns correctly inside th

2019-06-18 12:44:15 -0500 received badge  Notable Question (source)
2019-06-10 16:29:44 -0500 received badge  Notable Question (source)
2019-06-06 09:52:47 -0500 received badge  Notable Question (source)
2019-05-20 02:37:24 -0500 marked best answer Error: Config file has not been declared.

HI I am trying to build package: performance_test

It has a configuration file @ performance_test->cfg->performanceTest.cfg. package contains a simple publisher and subscriber.

Screen shot of my files is attached.Please zoom if isn't clear. Any help would be greatly appriciated.

Error: /home/nth/ocean_ws/src/performance_test/src/talker_node.cpp:21:41: error: ‘performance_test::performanceTestConfig’ has not been declared
   void configCallback(performance_test::performanceTestConfig &config, uint32_t level);

image description

image description

2019-05-20 02:37:21 -0500 marked best answer loop rate of a subscriber ?

Hi How can i find the loop rate of a subscriber/subscriber callback ?

Thanks

2019-05-20 01:56:20 -0500 marked best answer Transfer a point(x,y,z) between frames
 geometry_msgs::PointStamped initial_pt; 
 ros::Publisher odom_pub = node.advertise<geometry_msgs::vector3>("/visualization_marker", 1);
 tf2_ros::Buffer tfBuffer; 
 tf2_ros::TransformListener tfListener(tfBuffer);

ros::Rate rate(10.0);
while (node.ok()){

geometry_msgs::TransformStamped transformStamped;
try{
  transformStamped = tfBuffer.lookupTransform("/base_1", "/base_2", ros::Time(0));
}
catch (tf2::TransformException &ex) {
  ROS_WARN("%s",ex.what());
  ros::Duration(1.0).sleep();
  continue;
}

geometry_msgs::PointStamped  transformed_pt ; 
?
? 
?

Hi, I am trying to transfer a point from frame base_1 to base_2. Went through online search but not convinced how to proceed after this . tf2 listener tutorial Any help would be greatly appreciated.

2019-05-20 01:34:49 -0500 marked best answer NormalEstimation for 2D point cloud

Hi,

Is there a way to estimate normals for a 2D point cloud (XY plane & Unorganized point cloud) . To give a small background the point cloud is formed from Laser scan messages using laser_geometry package.

As per the PCL documentation, it try to fit a plane and estimate the normal but in my case all the points are present in a plane. So is there a way to find the normal lying the same 2D plane. Some thing like fitting a line and finding the norm.

Thank you.

2019-05-20 01:17:32 -0500 marked best answer How to call a service with begin and end time as request/input

Hi,

I am looking to call laser_assembler call back service -AssembleScans .

time begin
time end
---
sensor_msgs/PointCloud cloud
  std_msgs/Header header
    uint32 seq
    time stamp
    string frame_id
  geometry_msgs/Point32[] points
    float32 x
    float32 y
    float32 z
  sensor_msgs/ChannelFloat32[] channels
    string name
    float32[] values

I am looking to call this service in my velocity call back function but not how to input choose the start and end time.

There is an example in laser_assembler package using timer call back

void timerCallback(const ros::TimerEvent& e)
{
    AssembleScans srv;
    srv.request.begin = e.last_real;
    srv.request.end   = e.current_real;
    client_.call(srv)
}

Now I am looking the same service from a velocity call back

void  velocity_cb (const geometry_msgs::Twist& cmd_vel)
{
    AssembleScans srv;
    srv.request.begin = ???;
    srv.request.end   = ???;
}

Not sure how to input srv.request.begin , srv.request.end .

2019-05-20 01:11:56 -0500 marked best answer Cleaning dynamic memory allocation in a call back function.

Hi, My callback function looks like this.

void  cloud_cb (const sensor_msgs::PointCloud2ConstPtr& input_pc)
{
  // Convert the sensor_msgs/PointCloud2 data to pcl/PointCloud - Dataset
  pcl::PointCloud<PointT>::Ptr cloud_in(new pcl::PointCloud<PointT>);
  pcl::fromROSMsg(*input, *cloud_in);
  // pcl::norms
  pcl::PointCloud<pcl::Normal>::Ptr cloud_normals (new pcl::PointCloud<pcl::Normal>);
  ....
  ....
  for(auto searchPoint: filtered_cloud->points)
  {
    pcl::PCA<PointT> local_pca = new pcl::PCA<PointT>;
    pcl::PointIndices::Ptr inliers(new pcl::PointIndices());
    ....
    ....
   delete local_pca;
   delete inliers;
}
publisher(*cloud_normals);
// delete cloud;
// delete cloud_normals;
}

Is it a good practice to de-allocate memory for the variables "cloud" , "cloud_normals" after the end of callback function ?

2019-05-20 01:03:55 -0500 marked best answer Unable to launch lidar during boot

Hi,

I have an rplidar and i want to launch it during the booting. I followed a rosanswer here and was able to launch roscore during the bootup. But I am unable to launch rplidar.

/etc/systemd/system/
*********************rosCore.service************
[Unit]
Description=start roscore
After=network.target
Restart=on-abort

[Service]
ExecStart=/usr/local/bin/rosCoreService.sh

[Install]
WantedBy=default.target

**********************************************
/usr/local/bin/
*******************rosCoreService.sh **********
#!/usr/bin/env bash

bash -c "source /home/bc/.bashrc && roslaunch rplidar view_rplidar.launch"

****************************************************

I tried ./rosCoreService.sh directly and its working fine. In order to have port permissions I added KERNEL="ttyUSB0", GROUP:"bc", MODE = "0666" in /etc/udev/rules.d/50-usb-serial.rules

Since i need some port permission is "After=network.target" is correct ? or any suggestions ? I replaced "roslaunch rplidar view_rplidar.launch" with "roscore" and roscore is launching while bootup.

2019-05-20 01:00:54 -0500 received badge  Famous Question (source)
2019-03-28 06:53:28 -0500 marked best answer Where are velocities are set to zero in Joint group velocity controller.

Hi ,

I see that when ever velocity control is used , usually velocities are set to zero after certain time out (cmd_vel_timeout). which can be observed in differential drive controller.

But in the case of "joint_group_velocity_controller" which refers to "forward_joint_group_command_controller " , I am unable to find where the velocities are set to zero after a specified time ?

I also see that there is no time stamp in the joint group velocity controller ?

Thanks.

2019-03-27 05:02:28 -0500 received badge  Popular Question (source)
2019-03-26 12:56:03 -0500 edited question Where are velocities are set to zero in Joint group velocity controller.

Where are velocities are set to zero in Joint group velocity controller. Hi , I see that when ever velocity control is

2019-03-26 12:55:30 -0500 asked a question Where are velocities are set to zero in Joint group velocity controller.

Where are velocities are set to zero in Joint group velocity controller. Hi , I see that when ever velocity control is

2019-03-09 14:01:24 -0500 commented question Syntax for ros service with message type string array in request.

Yes, I am using tab completion rosservice call /joint_service "joint_names: - ''" After which, i filled in joint c1 a

2019-03-09 09:07:28 -0500 received badge  Notable Question (source)
2019-03-09 05:51:51 -0500 asked a question Syntax for ros service with message type string array in request.

Syntax for ros service with message type string array in request. Hi, My service message looks like this. string[] joi

2019-03-09 04:54:49 -0500 received badge  Famous Question (source)
2019-03-06 09:01:01 -0500 received badge  Popular Question (source)
2019-03-04 12:26:26 -0500 commented question Unable to load PID controller

Yes, you are right. How can i accept your comment as an answer ?

2019-03-04 12:25:03 -0500 commented question Unable to load PID controller

Yes, you are right.

2019-03-04 06:10:01 -0500 edited question Unable to load PID controller

Unable to load PID controller Hi, I am trying to write my own controller, where i want to add some PID. #include &l

2019-03-04 06:09:32 -0500 asked a question Unable to load PID controller

Unable to load PID controller Hi, I am trying to write my own controller, where i want to add some PID. #include &l

2019-03-03 18:53:18 -0500 received badge  Popular Question (source)