Search found 5 matches

by Zhiwu
Mon Sep 23, 2019 3:04 am
Forum: General Bullet Physics Support and Feedback
Topic: Why timeStep have to be this unreasonably small?
Replies: 7
Views: 8338

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 POSITI...
by Zhiwu
Sat Sep 14, 2019 8:51 pm
Forum: General Bullet Physics Support and Feedback
Topic: Why timeStep have to be this unreasonably small?
Replies: 7
Views: 8338

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)...
by Zhiwu
Fri Sep 06, 2019 4:59 am
Forum: General Bullet Physics Support and Feedback
Topic: Why timeStep have to be this unreasonably small?
Replies: 7
Views: 8338

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. Hi Steven, Thank you for your reply. Actually I found that it was my fault. I am using global variable m=5 for the figs but I put m=8 in the codes....
by Zhiwu
Mon Sep 02, 2019 7:22 am
Forum: General Bullet Physics Support and Feedback
Topic: Why timeStep have to be this unreasonably small?
Replies: 7
Views: 8338

Why timeStep have to be this unreasonably small?

Hello All, I am using the newest released stable PyBullet (Bullet 2) to simulate a soft bender as several rigid segments connected with hinge joints and motors. The problem that I have is the timeStep has to be unreasonably small (as low as ~0.2 us) to get physically right result. I say it is unreas...
by Zhiwu
Mon Jul 22, 2019 2:08 pm
Forum: General Bullet Physics Support and Feedback
Topic: How to understand the physics model of a motor?
Replies: 0
Views: 4765

How to understand the physics model of a motor?

Hi All, I am new to Bullet/PyBullet. I am confused about the physics model of a motor. For two bodies connected to one joint (p.JOINT_REVOLUTE), for a torque-controlled motor, physically where are the force applied on both bodies (what is the force and what is the lever arm vector)? I am trying to w...