[ros-users] values are zero in joint.h

Top Page
Attachments:
Message as email
+ (text/plain)
Delete this message
Reply to this message
Author: Andreas Vogt
Date:  
To: ros-users
Subject: [ros-users] values are zero in joint.h
Hi,

The values,

/// The joint position in radians or meters (read-only variable)
double position_;
/// The joint velocity in randians/sec or meters/sec (read-only variable)
double velocity_;
/// The measured joint effort in Nm or N (read-only variable)
double measured_effort_;

are zero all the time but the joint is turning. Where is the problem?

I am using this in the xml:

<transmission name="joint_p-a1_trans" type="SimpleTransmission">
                <actuator name="joint_p-a1_motor" />
                <joint name="joint_p-a1" />
                <mechanicalReduction>1</mechanicalReduction>
                <motorTorqueConstant>1</motorTorqueConstant>
    </transmission>


in the yaml:

  my_controller_ns:
    type: MyControllerPlugin
    wheel1: joint_c-w1



in the code:


  wheel1_state = robot->getJointState(wheel1);
  if (! wheel1_state )
  {
    ROS_ERROR("MyController could not find joint named '%s'",
               wheel1.c_str());
    return false;
  }
...
...
ROS_ERROR(  wheel1_state>commanded_effort etc...


--

Andreas Vogt
Logistics and Production Robotics

DFKI Bremen
Robotics Innovation Center
Robert-Hooke-Straße 5
28359 Bremen, Germany

Phone: +49 (0)421 218-64140
Fax: +49 (0)421 218-64150
E-Mail:

 Weitere Informationen: http://www.dfki.de/robotik
 -----------------------------------------------------------------------
 Deutsches Forschungszentrum fuer Kuenstliche Intelligenz GmbH
 Firmensitz: Trippstadter Straße 122, D-67663 Kaiserslautern
 Geschaeftsfuehrung: Prof. Dr. Dr. h.c. mult. Wolfgang Wahlster 
 (Vorsitzender) Dr. Walter Olthoff
 Vorsitzender des Aufsichtsrats: Prof. Dr. h.c. Hans A. Aukes
 Amtsgericht Kaiserslautern, HRB 2313
 Sitz der Gesellschaft: Kaiserslautern (HRB 2313)
 USt-Id.Nr.:    DE 148646973
 Steuernummer:  19/673/0060/3