search

bulletphysics / bullet3

Bullet Physics SDK: real-time collision detection and multi-physics simulation for VR, games, visual effects, robotics, machine learning etc.
http://bulletphysics.org
Other
12.4k stars 2.86k forks source link

About the robot arm drops naturally #3346

Closed ZisongXu closed 3 years ago

ZisongXu commented 3 years ago

Pls help me. I am having some problems with the robot arm. (The urdf file for the robot arm was written with my own reference). When I move the robot arm to a position (tilt), I no longer care about the robot arm and the robot arm moves down on its own over time. image image We can see the UR5 robot on the left moving slowly on its own, which is an interesting phenomenon and how I should have avoided it. This is my "UR5.urdf": `<?xml version="1.0" encoding="utf-8" ?>

`

ZisongXu commented 3 years ago

image The third picture.

erwincoumans commented 3 years ago

When I move the robot arm to a position (tilt),

Are you using position control for all joints? (pybullet.setJointMotorControl2(robot, joint, pybullet.POSITION_CONTROL, pos,...) See https://github.com/bulletphysics/bullet3/blob/master/examples/pybullet/gym/pybullet_examples/vr_kuka_setup.py#L46

Also, load the URDF using useFixedBase=True

and URDF files need elements, see the URDF for KUKA.

ZisongXu commented 3 years ago

When I move the robot arm to a position (tilt),

Are you using position control for all joints? (pybullet.setJointMotorControl2(robot, joint, pybullet.POSITION_CONTROL, pos,...) See https://github.com/bulletphysics/bullet3/blob/master/examples/pybullet/gym/pybullet_examples/vr_kuka_setup.py#L46

Also, load the URDF using useFixedBase=True

and URDF files need elements, see the URDF for KUKA.

I just used mouse to move and control the ur5 robot and the robot will move down by itself.