justinkgoh's profile - activity

I have tried it in several places. Including the one you suggested in the gazebo wiki site. The other ones I have tried are from here and here.

When I do that I get an error that says this:

CMake Error at robsim/robsim_gazebo/CMakeLists.txt:214 (target_link_libraries):
        Cannot specify link libraries for target "publisher_node" which is not
        built by this project.

What I mean by install is that I want to use the .c and .h files from ulapi (which is what we use to talk to the robot arms we have in the lab) in my c++ code I have written. I am familiar with the way you install libraries for arduino if that is of any help.

The files I have are C and H. I am use to installing libraries for Arduino and was wondering how to do it for ROS.

I managed to get it working without using a plugin. Thanks for your time and help!

I am wondering how I would incorporate a library in ROS. The library I am trying to install is called ulapi to communicate with the kuka robot we have in the lab.

Thanks

Update (7.13.16): Here is part of my code that I am trying to add the ulapi library. Might be useful.

#include <ros/ros.h>

//library for type of message sent to gazebo topics
#include <std_msgs/Float64.h>

//libraries to control model in gazebo
#include <geometry_msgs/Pose.h>
#include <geometry_msgs/Twist.h>
#include <gazebo_msgs/ModelState.h>
#include <gazebo_msgs/SetModelState.h>

#include <cstdlib>
#include <robsim_gazebo/ulapi.h>

int main (int argc, char** argv)
{
    //initialize node
    ros::init(argc, argv, "publisher_node");

    //create node handle
    ros::NodeHandle rob_pose;

    ros::NodeHandle a1a2;
    ros::NodeHandle a2e1;
    ros::NodeHandle e1a3;
    ros::NodeHandle a3a4;
    ros::NodeHandle a4a5;
    ros::NodeHandle a5a6;
    ros::NodeHandle a6tp;

Here is the part of my CMakeLists.txt file

add_library(unix_ulapi src/unix_ulapi.c)
#target_link_libraries(publisher_node unix_ulapi)

add_library(ulapi_getopt src/ulapi_getopt.c)
#target_link_libraries(publisher_node ulapi_getopt)

Thanks fixed my issue.

Im trying to write c++ code to publish joint angles to have Gazebo update the model.

I am getting this error message:

Client [/gazebo] wants topic /kuka/a1_a2_joint_position_controller/command to have datatype/md5sum [std_msgs/Float64/...], but our version has [trajectory_msgs/JointTrajectoryPoint/...]. Dropping Connection

My knowledge of C++ is limited and the version of ROS im using is Indigo and Gazebo is 2.2.3

Here is the code I have written for the publisher:

{
    ros::init(argc, argv, "publisher_node");
    ros::NodeHandle p;

    ros::Publisher a1_a2_pub = p.advertise<trajectory_msgs::JointTrajectoryPoint>("/kuka/a1_a2_joint_position_controller/command", 1000);

    ros::Rate rate(10);

    while (ros::ok())
    {
    trajectory_msgs::JointTrajectoryPoint msg; //= new trajectory_msgs::JointTrajectoryPoint();

    msg.positions.resize(6);
    msg.positions[0] = 1.0;

    a1_a2_pub.publish(msg);

    //ROS_INFO_STREAM("Sending position command" << msg.positions[0]);

    rate.sleep();
    ros::spinOnce();
    }
    return 0;
}

UPDATE: Here is the working final code:

#include "ros/ros.h"
#include "std_msgs/Float64.h"
#include <iostream>
#include "trajectory_msgs/JointTrajectory.h"

#include <cstdlib>

int main (int argc, char** argv)
{
ros::init(argc, argv, "publisher_node");
ros::NodeHandle a1a2;
ros::NodeHandle a2e1;
ros::NodeHandle e1a3;
ros::NodeHandle a3a4;
ros::NodeHandle a4a5;
ros::NodeHandle a5a6;
ros::NodeHandle a6tp;

ros::Publisher a1_a2_pub = a1a2.advertise<std_msgs::Float64>("/kuka/a1_a2_joint_position_controller/command", 1000);
ros::Publisher a2_e1_pub = a2e1.advertise<std_msgs::Float64>("/kuka/a2_e1_joint_position_controller/command", 1000);
ros::Publisher e1_a3_pub = e1a3.advertise<std_msgs::Float64>("/kuka/e1_a3_joint_position_controller/command", 1000);
ros::Publisher a3_a4_pub = a3a4.advertise<std_msgs::Float64>("/kuka/a3_a4_joint_position_controller/command", 1000);
ros::Publisher a4_a5_pub = a4a5.advertise<std_msgs::Float64>("/kuka/a4_a5_joint_position_controller/command", 1000);
ros::Publisher a5_a6_pub = a5a6.advertise<std_msgs::Float64>("/kuka/a5_a6_joint_position_controller/command", 1000);
ros::Publisher a6_tp_pub = a6tp.advertise<std_msgs::Float64>("/kuka/a6_tp_joint_position_controller/command", 1000);

//ROS_INFO_STREAM("PUBLISHER");

ros::Rate rate(10);

while (ros::ok())
{
std_msgs::Float64 a1a2msg;
std_msgs::Float64 a2e1msg;
std_msgs::Float64 e1a3msg;
std_msgs::Float64 a3a4msg;
std_msgs::Float64 a4a5msg;
std_msgs::Float64 a5a6msg;
std_msgs::Float64 a6tpmsg;
//ROS_INFO_STREAM("OBJECT");

a1a2msg.data = rand() % 2 + -2;
a2e1msg.data = rand() % 3 + 0;
e1a3msg.data = rand() % 2 + -2;
a3a4msg.data = rand() % 2 + -2;
a4a5msg.data = rand() % 2+ -2;
a5a6msg.data = rand() % 2 + -2;
a6tpmsg.data = rand() % 2 + -2;

ROS_INFO_STREAM("A1 / A2: " << a1a2msg.data);
ROS_INFO_STREAM("A2 / E1: " << a2e1msg.data);
ROS_INFO_STREAM("E1 / A3: " << e1a3msg.data);
ROS_INFO_STREAM("A3 / A4: " << a3a4msg.data);
ROS_INFO_STREAM("A4 / A5: " << a4a5msg.data);
ROS_INFO_STREAM("A5 / A6: " << a5a6msg.data);
ROS_INFO_STREAM("A6 / TP: " << a6tpmsg.data);

a1_a2_pub.publish(a1a2msg);
a2_e1_pub.publish(a2e1msg);
e1_a3_pub.publish(e1a3msg);
a3_a4_pub.publish(a3a4msg);
a4_a5_pub.publish(a4a5msg);
a5_a6_pub.publish(a5a6msg);
a6_tp_pub.publish(a6tpmsg);
//ROS_INFO_STREAM("PUBLISH");

rate.sleep();
ros::spinOnce();
}
return 0;
}

Update: I was able to get the subscriber working and now I am having issues with the publisher.

Hi, I am wondering if you could send me your code for the subscriber. I am also a beginner and trying to get a subscriber and publisher thing going as well.

Thanks.

I apologize if what I wrote is confusing. I am not a computer science major. Is there anything I can provide that would be helpful in clearing whether I would need a gazebo plugin or not. I would like to stay away from plugins if possible since my programming knowledge is limited.

Hello all, I am new to ROS and I am trying to write a subscriber and publisher c++ code to talk with Gazebo. I want to get the states of each link and be able to publish to each link to control its joint angles.

I was successfully able to control my model in Gazebo via a rostopic pub command and am struggling to write a c++ code to do the same. Similarly, I have not been able to write any code to get the link states. I was able to get code working to subscribe to the /joint_states, but this does not reflect the link states in Gazebo.

Any help would be appreciated!

Ubuntu: 14.04 LTS ROS: Indigo Gazebo: 2.2.3

I am wondering if rviz has a collision detection system similar to gazebo implemented. I see that there is an option to enable collision, but I have not found and information online about what it does exactly.

Ubuntu 14.04 LTS ROS: Indigo