RohitM's profile - activity

I have successfully implemented the global_planner and my own global planner plugin(RRTstar) for the teb_local_planner. I've found that the teb_local_planner is very efficient is avoiding obstacles. My doubt is, what is the role of the global planner in this? I do understand that the local planner is merely optimizing the trajectory provided by the global planner. But, going by the analogy that the local planner is like an elastic band, why couldn't we merely have selected a straight line between the start and goal point and use teb_local_planner to weave its way through the obstacles since it is effectively doing that with a global planner as well.

Also, am I wrong in understanding that the teb local planner works similar to the potential field planners? Do they suffer from the same drawbacks?

Any help would be much appreciated!

Unable to use python speech_recognition package I am trying to use the python speech_recognition package with ros. If I

I run Tensorflow in a virtual environment and I want to run a python node in this virtual environment. I'm getting an error saying:

ImportError: No module named 'rospkg'

I've tried running source ./devel/setup.bash but that didn't help solve the problem.

Does anyone have any suggestions on how to solve this problem?

Thanks in advance.

I have attempted two ways to add a dynamic obstacle neither of which have worked:

1. I added a simple model and added a velocity attribute to it which should give it an initial velocity as mentioned here. But for some reason that I have not understood, this method is not working.

2. I added another position model (thus making it two robots in my simulation) so that I can try to pass messages to my dynamic obstacle through the robot_1/cmd_vel topic. After debugging the many tf errors that come I have finally got rid of errors in rviz. However the obstacles are not visible in rviz even though they are visible in Stage. Not sure how to solve this error either.

Any help will be highly appreciated. If you require any additional information to help understand the problem then I can add them at the earliest.

I am attempting to use the ROBOTIS-Manipulator Code in ROS Indigo on Ubuntu 14.04. It is successfully executing catkin_make but is giving an error in roslaunch. After a lot of time I think that I have figured out that the error is in the following code snippet. I outputted the value of error and as shown below, it is giving 1 => EPERM (No permission to set the scheduling policy and parameters specified in attr). How to solve this error?

Error:

[ INFO] [1464938807.597236403]: error: 1
[ERROR] [1464938807.597311436]: timer thread create fail!!
terminate called after throwing an instance of 'boost::exception_detail::clone_impl<boost::exception_detail::error_info_injector<boost::lock_error> >'

Code Snippet:

// create and start the thread
        if((error = pthread_create(&this->timer_thread_, &attr, this->ThreadProc, this))!= 0) {ROS_INFO("error: %d", error);
            ROS_ERROR("timer thread create fail!!");
            exit(-1);
        }

I am publishing the pose from a node and receiving it another node. For some reason the subscriber is always getting a 0 value. Below is the ROS_INFO output of both the published message and the subscribed message.

[ INFO] [1467443650.648643683]: 0.174000    -0.289000     -0.275000

[ INFO] [1467443634.965920060]: 0.000000      0.000000       0.000000

This is a code snippet of the callback function where I am ROS_INFOing the message.

void BaseModule::KinematicsPoseMsgCallback( manipulator_base_module_msgs::KinematicsPose msg) 
{   
    if( enable == false )
        return;
    ROS_INFO("%f      %f       %f", msg.pose.position.x, msg.pose.position.y, msg.pose.position.z);
    Robotis->kinematics_pose_msg = msg;

Does anyone know why this might be the case? Please tell me if you need any more information to solve this problem. Thanks.

Edit: These are the publisher messages:

ros::Publisher k_i = n.advertise<manipulator_base_module_msgs::KinematicsPose>("kinematics_input", 10);
manipulator_base_module_msgs::KinematicsPose kin;
kin.pose.position.x = 0.174;
kin.pose.position.y = -0.289;
kin.pose.position.z = -0.275;
k_i.publish(kin);

Hi,

I am trying to transform a velocity from one frame to another. I want to use the transformVector3 function as mentioned in this link. Since it requires a StampedVector I am trying to convert the datatype using the function tf::vector3StampedMsgtoTF. I am writing my node in Python but I cannot find the Python version of the above tf functions anywhere.

Any help will be much appreciated.

ps. Does using tf2 avoid the explicit conversion of a geometry message to TF datatypes?

I've been using ROS for a couple of years and Rviz has been working satisfactorily till now. I'm not sure what I've done but I'm getting the error mentioned in the question ( [rospack] Error: package 'rviz' not found ) while executing the following statements:

rosrun rviz rviz 
rospack find rviz

Yes, I have sourced the required directories, this is the output to echo $ROS_PACKAGE_PATH

/home/rohit/glocal/src:/opt/ros/indigo/share:/opt/ros/indigo/stacks

ps. My original error was that one of my launch files which runs the rviz node was giving the following error:

ERROR: cannot launch node of type [rviz/rviz]: rviz
ROS path [0]=/opt/ros/indigo/share/ros
ROS path [1]=/home/rohit/glocal/src
ROS path [2]=/opt/ros/indigo/share
ROS path [3]=/opt/ros/indigo/stacks

This made me suspect that my rviz package wasn't being found which is the primary error according to me. Any help will be much appreciated.

I am writing a global planner plugin for the navigation stack using OMPL. I need to convert the Costmap2D in ROS to its corresponding State Space representation. Has anyone done this before?

Sorry mate, I wrongly thought that I was using Python 2.7. I checked my virtual environment and I was actually running P

Thanks for the reply. Turns out that I needed to pip install rospkg catkin_pkg

ImportError: dynamic module does not define init function (PyInit__tf2) I'm running Python 2.7 and when I try to import

Running ROS in a Tensorflow virtual environment I run Tensorflow in a virtual environment and I want to run a python nod

Hi,

I am trying to use DSRC for V2I communication. Does anyone have any tips or resources on how I can begin interfacing ROS with DSRC, I am currently unable to find any resources to help me get started with this. Any help will be much appreciated.

Thanks, Rohit.

The reason ROS2 will be difficult is that our publishers are written in python and the ros1_bridge works for C++ message

After that the message is sent from the computer to the radio device (perhaps via ethernet) and published using radio as

Thanks so much for your suggestions. I'm not very knowledgeable in communication theory so please tell me if I'm underst

Thanks so much for that info! We would definitely try to have an IP network available but it will be a little difficult.