Search found 83 matches
- Mon Nov 11, 2019 9:37 am
- Forum: General Bullet Physics Support and Feedback
- Topic: What parameters to tune to stabilize collisions
- Replies: 8
- Views: 12337
Re: What parameters to tune to stabilize collisions
looks not so reasonable. I will check it again later.
- Mon Nov 11, 2019 9:00 am
- Forum: General Bullet Physics Support and Feedback
- Topic: What parameters to tune to stabilize collisions
- Replies: 8
- Views: 12337
Re: What parameters to tune to stabilize collisions
i just take a test that change the gravity acceleration to setGravity(0, 0, -0.981) and set robot initial position to robot_init_pos=(0, 0, 200) and then after a while we can find that the base velocity sometimes become very large. i also debug this case and find the acceleration of the base and joi...
- Thu Nov 07, 2019 11:40 am
- Forum: General Bullet Physics Support and Feedback
- Topic: What parameters to tune to stabilize collisions
- Replies: 8
- Views: 12337
Re: What parameters to tune to stabilize collisions
thanks for your sharing. i think it should be caused by your selected actions which maybe make the robot jump very high.
- Mon Oct 14, 2019 5:24 am
- Forum: PyBullet Support and Feedback
- Topic: Simulating an KUKA LBR iwaa
- Replies: 2
- Views: 4312
Re: Simulating an KUKA LBR iwaa
Could you provide a complete simple test? thanks.
- Wed Oct 09, 2019 12:53 am
- Forum: Research and development discussion about Collision Detection and Physics Simulation
- Topic: Bullet softbody cloth was stretched away
- Replies: 1
- Views: 35659
Re: Bullet softbody cloth was stretched away
very interesting! have you found the rootcause?
- Wed Sep 25, 2019 3:36 am
- Forum: General Bullet Physics Support and Feedback
- Topic: Why timeStep have to be this unreasonably small?
- Replies: 7
- Views: 8362
Re: Why timeStep have to be this unreasonably small?
This is from the assumption of linear elasticity. Similar to Hooke's Law, the torque is promotional to how much it displaces from the equilibrium position (angle). i hava an intuition that the torque of joint near the base should be larger than the joint near the end given the same delta theta, rig...
- Mon Sep 16, 2019 1:26 pm
- Forum: General Bullet Physics Support and Feedback
- Topic: Why timeStep have to be this unreasonably small?
- Replies: 7
- Views: 8362
Re: Why timeStep have to be this unreasonably small?
sorry, i still don't understand why this function be written like that. i have some questions as below. 1. where do these constants come from such as -1.5e-3, 1.5735*1e5? 2. why the joint torque only have relation with the joint delta theta(if not consider the damping)? also you can call the POSITIO...
- Wed Sep 11, 2019 8:56 am
- Forum: General Bullet Physics Support and Feedback
- Topic: Why timeStep have to be this unreasonably small?
- Replies: 7
- Views: 8362
Re: Why timeStep have to be this unreasonably small?
i change your code to use the POSITION_CONTROL mode with (5e-3)/240 us timestep which is bigger than what you used and it can work well as below. if you have to use the TORQUE_CONTROL mode based on some other consideration, Could you explain your function of TorVolThe(Theta,angularVelocity,Voltage)?...
- Thu Sep 05, 2019 2:27 am
- Forum: General Bullet Physics Support and Feedback
- Topic: Why timeStep have to be this unreasonably small?
- Replies: 7
- Views: 8362
Re: Why timeStep have to be this unreasonably small?
hi Could you tell me the bullet version you used? i am testing this case with the attached code but get a different result.
my bullet version is 2.5.5.
my bullet version is 2.5.5.
- Tue Aug 27, 2019 12:58 am
- Forum: General Bullet Physics Support and Feedback
- Topic: unstable soft body similation
- Replies: 3
- Views: 4166
Re: unstable soft body similation
Could you email these object files to me, shengjun89@163.com? thanks.
- Mon Aug 26, 2019 6:25 am
- Forum: General Bullet Physics Support and Feedback
- Topic: unstable soft body similation
- Replies: 3
- Views: 4166
Re: unstable soft body similation
Could you attach all your body object? thanks.
- Mon Jul 01, 2019 12:47 pm
- Forum: PyBullet Support and Feedback
- Topic: What accuracy to expect for trajectory tracking using position control
- Replies: 6
- Views: 8608
Re: What accuracy to expect for trajectory tracking using position control
in the second case, the robot collides with the ground which will impact the links and joints of the robot.
- Sun Jun 30, 2019 5:45 am
- Forum: PyBullet Support and Feedback
- Topic: What accuracy to expect for trajectory tracking using position control
- Replies: 6
- Views: 8608
Re: What accuracy to expect for trajectory tracking using position control
thanks for your sharing. why did you said "maximum of 0.01 for some joint"? i add the following to print the max delta, the value is about 0.006. how much tracking accuracy do you need? the accuracy is very high if don't care about the velocity. print("max value=", np.max(robotlo...
- Fri Jun 28, 2019 1:39 am
- Forum: PyBullet Support and Feedback
- Topic: What accuracy to expect for trajectory tracking using position control
- Replies: 6
- Views: 8608
Re: What accuracy to expect for trajectory tracking using position control
Could you provide a complete simple test? i can work with you to find the root cause.
- Wed May 29, 2019 11:51 am
- Forum: General Bullet Physics Support and Feedback
- Topic: Incorrect results when simulating multiple bodies
- Replies: 8
- Views: 6107
Re: Incorrect results when simulating multiple bodies
hi tgreif,
sorry, it is hard for me to reproduce your issue. hope next time i can help you. good luck!
sorry, it is hard for me to reproduce your issue. hope next time i can help you. good luck!