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2013-07-26 13:12:14 -0500 commented question Controlling a Mobile Robot with its Range Sensor

@iche033 I am using gazebo 1.8.7 now. I am using SDF 1.4. No there are not error/warning message in the terminal.

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2013-07-15 22:46:15 -0500 commented question Controlling a Mobile Robot with its Range Sensor

@iche033 Hi thanks for the comment. I noticed my mistake and have updated the question accordingly.

2013-07-15 14:42:22 -0500 asked a question Controlling a Mobile Robot with its Range Sensor

Hi all,

I am following the tutorial in this link: http://gazebosim.org/wiki/Tutorials/1.3/control_robot/mobile_base_laser. The robot and the sensor are working properly as mentioned in the Prerequisites. I have copied the code exactly mentioned in the tutorial.However When I spawned the robot into the world it does not stop when it reaches 2 meters in front of obstacle and keeps moving on until it hits the obstacle. I cant figure out what's going wrong over here. I am using gazebo 1.8.6 for this. Any help would be highly appreciated.

Thank you.

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2013-06-21 15:48:13 -0500 asked a question problem using arm navigation with Atlas arm?

I am trying to use arm_navigation package with Atlas mainly for finding IK solution of Atlas arm. I am following tutorial in the following link: http://www.ros.org/wiki/arm_navigation/Tutorials. I used planning description configuration wizard to generate a package with name "atlas_arm_navigation". Within this package is a launch file called "atlas_arm_navigation.launch". Based on the tutorial to use the package my next step is to use the following command: roslaunch atlas_arm_navigation atlas_arm_navigation.launch. When I enter this command in the terminal following error message comes out: 'waitForService: Service [/register_planning_scene] has not been advertised, waiting... Waiting for robot state ... Waiting for robot state ... Waiting for environment server planning scene registration service /register_planning_scene'. I have seen similar issue being asked here. Based on the answer in the given link and looking at the fake_pub.py of turtlebot I created a node that would publish the joint angles in Atlas arm. My code looks at follows:

!/usr/bin/env python

import roslib; roslib.load_manifest("my_joint_state_publisher") import rospy from sensor_msgs.msg import JointState

rospy.init_node("fake_pub") p = rospy.Publisher('joint_states', JointState)

msg = JointState() msg.name = ['back_lbz', 'back_mby', 'back_ubx', 'neck_ay', 'l_leg_uhz', 'l_leg_mhx', 'l_leg_lhy', 'l_leg_kny', 'l_leg_uay', 'l_leg_lax', 'r_leg_uhz', 'r_leg_mhx', 'r_leg_lhy', 'r_leg_kny', 'r_leg_uay', 'r_leg_lax', 'l_arm_usy', 'l_arm_shx', 'l_arm_ely', 'l_arm_elx', 'l_arm_uwy', 'l_arm_mwx', 'r_arm_usy', 'r_arm_shx', 'r_arm_ely', 'r_arm_elx', 'r_arm_uwy', 'r_arm_mwx']

msg.position = [-1.825729896154371e-06, 0.0012158011086285114, 3.1900293834041804e-05, -0.6108962893486023, -0.014087767340242863, 0.0600777342915535, -0.23434774577617645, 0.5147263407707214, -0.27372151613235474, -0.06056824326515198, 0.014155304990708828, -0.06070755794644356, -0.23345401883125305, 0.5148292183876038, -0.2747017741203308, 0.06044372543692589, 0.29961875081062317, -1.30330491065979, 2.0006399154663086, 0.49854737520217896, 0.00045716011663898826, -0.0025867922231554985, 0.29961803555488586, 1.3032892942428589, 2.000636577606201, -0.49854570627212524, 0.00045820337254554033, 0.002590071177110076]

msg.velocity = [0.00013856934674549848, 0.000154771376401186, -0.0001353632687823847, 0.008212480694055557, -0.00041940310620702803, -0.0005069326725788414, -0.00045518350088968873, 0.0008471862529404461, -0.0038269900251179934, -0.0011595507385209203, 0.0007314747199416161, 0.0002890885516535491, -0.0004049588169436902, 0.0005705549847334623, -0.002361031249165535, 0.00222948519513011, -0.00025113363517448306, -9.360113472212106e-05, -0.0003189251001458615, -0.00036248480319045484, 8.628344221506268e-05, 0.0003728768788278103, -0.0001802600163500756, 0.00012022889859508723, -0.0002849512093234807, 0.00032948522130027413, 6.529196980409324e-05, -0.00028708099853247404]

while not rospy.is_shutdown(): msg.header.stamp = rospy.Time.now() p.publish(msg)
print("message published") rospy.sleep(0.1)

Even when I run this node the error message still continues to come in the terminal. I don't know what to do next? I would really appreciate if anyone with previous experience with Arm navigation have any suggestions for me. I am using ros Fuerte, Gazebo 1.8.2 and drcsim 2.6.6.1 in ubuntu 12.04. Thank you.

2013-06-19 14:18:59 -0500 commented answer Inverse kinematics for Atlas Arm?

@Francisco I tried following your instructions. But when I type the following command in the terminal "roslaunch atlas_arm_navigation atlas_arm_navigation.launch" following message keeps coming on the screen " waitForService: Service [/register_planning_scene] has not been advertised, waiting... , Waiting for robot state ..., Waiting for joint state ..., Waiting for environment server planning scene registration service /register_planning_scene". I don't know what to do next??

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2013-06-18 13:55:09 -0500 commented answer Inverse kinematics for Atlas Arm?

@nkoenig Thanks for the reply. I have one question though. MoveIt seems to be better as it is going to replace arm_navigation. However It is not available for fuerte!! And drcsim comes along with fuerte. So I think I should either try to run drcsim with groovy or run moveit on fuerte. Which one do you think is better option??

2013-06-16 13:56:31 -0500 commented answer Inverse kinematics for Atlas Arm?

Thanks for the reply. I'll give it a try.

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2013-06-14 12:13:44 -0500 asked a question Inverse kinematics for Atlas Arm?

Hi All. I am trying to find out the Inverse Kinematic solution for the Atlas Arm. I am trying to use the 'arm_kinematics' package for this. The steps I used for this are as follows:

I entered the following commands in seperate terminals:

  1. roslaunch urdf_tutorial display.launch model:=atlas_sandia_hands.urdf

  2. roslaunch atlas_utils atlas_sandia_hands.launch

In a separate terminal I entered the following commands:

  1. rosparam set urdf_xml robot_description
  2. rosparam set robot_description atlas_sandia_hands.urdf
  3. rosparam set arm_kinematics/root_name utorso
  4. rosparam set arm_kinematics/tip_name l_hand
  5. rosparam set maxIterations 1000
  6. rosrun arm_kinematics arm_kinematics

Then I wrote a python script for finding out the IK solution. I tried following the tutorial for PR2 arm inverse kinematics. This is what I had:

! /usr/bin/env python

import roslib roslib.loadmanifest('tutorial_atlas_control') roslib.loadmanifest('geometry_msgs') roslib.load_manifest('kinematics_msgs')

import rospy, yaml, sys from atlas_msgs.msg import AtlasCommand from sensor_msgs.msg import JointState from std_msgs.msg import * from geometry_msgs.msg import * from kinematics_msgs.srv import * from arm_navigation_msgs.srv import *

class findik:

def get_ik(self, x, y, z):
    rospy.init_node('find_ik')

    self.ik_info = '/arm_kinematics/get_ik_solver_info'    

    print "waiting for ik service"
    rospy.wait_for_service(self.ik_info) 
    self.ik_info_service = rospy.ServiceProxy(self.ik_info, GetKinematicSolverInfo)
    self.ik_info_service.joint_names = ["l_arm_usy",
                                        "l_arm_shx",
                                        "l_arm_ely",
                                        "l_arm_elx",
                                        "l_arm_uwy",
                                        "l_arm_mwx"]
    self.ik_info_service.joint_names = ["utorso",
                                        "l_clav",
                                        "l_scap",
                                        "l_uarm",
                                        "l_larm",
                                        "l_farm",
                                        "l_hand"]


    self.ik_info_req = GetKinematicSolverInfoRequest()
    self.ik_info_res = self.ik_info_service.call(self.ik_info_req)    

    self.ik_service = rospy.ServiceProxy('arm_kinematics/get_ik', GetPositionIK, True)

    self.ik_req = GetPositionIKRequest()
    self.ik_req.timeout = rospy.Duration(5.0)
    self.ik_req.ik_request.ik_link_name = 'l_hand'
    self.ik_req.ik_request.ik_seed_state.joint_state.name = self.ik_info_res.kinematic_solver_info.joint_names
    self.ik_req.ik_request.ik_seed_state.joint_state.position = [0]*6

    self.ps = PoseStamped()
    self.ps.header.stamp = rospy.Time(0)
    self.ps.header.frame_id = 'pelvis'
    self.ps.pose.position.x = x
    self.ps.pose.position.y = y
    self.ps.pose.position.z = z

    self.ps.pose.orientation.x = 0
    self.ps.pose.orientation.y = 0
    self.ps.pose.orientation.z = 0
    self.ps.pose.orientation.w = 1.0

    self.ik_req.ik_request.pose_stamped = self.ps        

    self.ik_res = self.ik_service.call(self.ik_req)

if __name__ == '__main__': ik = findik() ik.get_ik(0.55, -0.15, 1.2)

However the command "self.ik_res = self.ik_service.call(self.ik_req)" would result in rospy exception and would stop the "arm_kinematics" node in the other terminal.

Has any one tried finding IK for Atlas. What Package did you use. If you used "arm_kinematics" did you run into similar problem?? Please let me know. I am using ros Fuerte, Gazebo 1.8.2 and drcsim 2.6.6.1 in ubuntu 12.04.

Any help will be highly appreciated. Thanks.

2013-06-08 13:44:27 -0500 commented question DRCsim Atlas robot inverse kinematics

Hi, were able to get the arm_kinematics package working for the finding the inverse kinematics of the Atlas arm??? I've been trying to do it myself for about a week now but without any luck?? If you were able to get it working could you please give me the steps on how you approached it. I am using ROS fuerte, Gazebo 1.8.2 for this.