Search found 13 matches

by johnrowlay
13 Mar 2019, 17:20
Forum: General questions
Topic: sim.generateIkPath always returns NULL
Replies: 2
Views: 1150

Re: sim.generateIkPath always returns NULL

Hello,

Yes, that was the reason.

Thank you very much!
by johnrowlay
13 Mar 2019, 14:01
Forum: General questions
Topic: sim.generateIkPath always returns NULL
Replies: 2
Views: 1150

sim.generateIkPath always returns NULL

I am having trouble getting the "sim.generateIkPath" function to work, and it is always returning NULL for me (i.e. no path could be computed). I have created a very simple scene with a Sawyer robot, and introduced a tip-target setup with an IK calculation module. The target is 10cm away f...
by johnrowlay
26 Feb 2019, 19:51
Forum: General questions
Topic: Joint torque seems insufficient
Replies: 1
Views: 1081

Joint torque seems insufficient

I have loaded the Sawyer robot arm into a new scene, set all joints to force-torque mode, with very large maximum torques (10^11) and "lock motor when target velocity is zero" checked. If I start running the simulation, as expected the robot does not move. If I then set the "Target ve...
by johnrowlay
13 Feb 2019, 16:24
Forum: General questions
Topic: sim.computeJacobian() is returning -1
Replies: 1
Views: 850

sim.computeJacobian() is returning -1

I am having trouble retrieving the Jacobian using the regular API. So, I have created a new scene, and then imported the Sawyer robot. Then, I created an IK group using the calculation modules, with a tip and a target, and explicit handling not checked. Then, I added a child script for the Sawyer ro...
by johnrowlay
16 Nov 2018, 14:04
Forum: General questions
Topic: Disabling the "V-REP crashed in last session" message
Replies: 1
Views: 1000

Disabling the "V-REP crashed in last session" message

I am running a V-REP server using the remote API in Python. Sometimes, if my code crashes during simulation and I do not shut down the server correctly, when I then launch a V-REP server on the same port, I receive the following error message: https://i.imgur.com/DOa73I4.png However, the answer in m...
by johnrowlay
24 Apr 2018, 17:37
Forum: General questions
Topic: Locking a joint angle
Replies: 3
Views: 2100

Re: Locking a joint angle

Hello, I am using the Vortex physics engine. But I seem to remember that the same thing sometimes happens with other physics engines too. If a joint is moved due to interaction with an object, then should it always be reset to the value in "Position [deg]" through the PID controller? Or sh...
by johnrowlay
22 Apr 2018, 11:53
Forum: General questions
Topic: Locking a joint angle
Replies: 3
Views: 2100

Locking a joint angle

Hello, I have a robot arm in V-Rep, which has a two-fingered gripper. What I want to do, is to maintain the gripper in the "closed" position, such that the two fingers are just touching each other. The robot will then interact with some objects on a table. To do this, in the Joint Properti...
by johnrowlay
03 Mar 2018, 03:37
Forum: General questions
Topic: Random movement of tip in IK setup
Replies: 1
Views: 1345

Random movement of tip in IK setup

I have imported the Kinova Mico arm into V-REP 3.5, and built a tip-target setup. The IK group uses pseudo-inverse with maximum of 10 iterations, and precisions of 5e-4 m and 1e-1 deg. All joints are in inverse kinematics mode, with 0.01 proportional gain. Using the Python remote API, I set the targ...
by johnrowlay
27 Feb 2018, 00:03
Forum: Bug reports
Topic: Grouping objects changes the axes
Replies: 1
Views: 1846

Grouping objects changes the axes

In V-REP 3.5, let's say I create a cuboid shape, and then copy that cuboid, and move it next to the first cuboid. The axes of the two cuboids are aligned at this point. Then, I group the two cuboids together using "Edit -> Grouping / Merging -> Group selected shapes", it groups the cuboids...
by johnrowlay
06 Feb 2018, 19:04
Forum: General questions
Topic: Limiting speed in inverse kinematics mode
Replies: 1
Views: 1516

Limiting speed in inverse kinematics mode

I have a robot arm with all joints in IK (hybrid) mode, and a tip-target IK calculation set up. The IK calculation uses DLS with a damping of 0.1, and maximum 100 iterations. When I start a simulation with the target about 50cm from the tip, the robot moves very quickly to the target, almost instant...