Questions tagged [friction]

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How to simulate torsional friction in Gazebo Sim like in Gazebo Classic?

In Gazebo Classic, it was possible to assign torsional friction to objects, as explained here https://classic.gazebosim.org/tutorials?tut=torsional_friction&cat=physics. However, when I follow the ...
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Problem with locomotion of hexabot in ROS2/Gazebo, wondering what the problem might be

Hi Robotics Stack Exchange Community, I am trying to build my first ROS2/Gazebo project and I want to simulate a six-legged robot. I have been trying to troubleshoot and look through documention as to ...
54 views

Can set friction direction based on link cordinate in URDF

I'm a beginner at gazebo and ROS. I'm trying to make mobile robot which propels itself using the friction force normal to the direction of wheel. I want to use cylinder as wheel, and set the friction ...
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How to simulate joint friction in gazebo

I sucessfully created a custom effort controller for my robot but I'm having an issue related to joint friction. I load the robot in gazebo and just compesate gravity, so the robot is still in the ...
4 views

Frictionless sphere stops spinning for smaller torques

Hello, I'm experimenting with Gazebo Classic v11.10.2 and friction coefficient. I added a unit sphere, set the mass to 120kg, and the mu1 and mu2 coefficient to 0.0. Then I apply a small torque (eg. &...
56 views

How does Gazebo compute the friction between two surfaces?

The friction is defined for a pair of surfaces. For example the rubber on asphalt. In Gazebo, however, we define a parameter 'friction' is set for each link. So suppose there is an object with surface ...
2 views

Simulated robot is building a tower of blocks in Gazebo 7, blocks are sliding

I'm trying to have a Sawyer robot build a tower out of blocks but the blocks keep sliding off each other. I'm using Gazebo version 7. I've tried increasing the friction but it made no difference. SDF ...
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Physics problem with simple movement of grasped object

The robot tool is a prismatic gripper with four rods that slip into matching holes on the object to be grasped. Using this gripper to move the object works fine for motion perpendicular to the rod ...
16 views

Grasping unable to lift object

Grasping is not working in this primitive case I've made. The object is a box of mass 1 and default friction and contact parameters. The gripper uses two prismatic joints to move two c-shaped links ...
47 views

Friction insufficient in grasping simulation

Update 2 Following some advice below I changed the ROS controller from EffortJointInterface to PositionJointInterface and this ...
2 views

robot slips after upgrade to kinetic

Dear all, After upgrading from Ubuntu 14.04 to 16.04 and from Indigo to Kinetic I'm experiencing a weird behavior from Gazebo and the HyQ robot model. The complete robot model can be found here. I ...
7 views

Friction Not Working Between URDF and Database Model

I am trying to model and control a conveyor using ROS/Gazebo, but right now it seems that objects I place on top of it just stay in place when I actuate it. Here are screenshots showing the collision ...
4 views

Robot tilting problem on linear acceleration

Hello, I am trying to simulate someting close to the Nexus 3-wheeled platform. When I accelerate with 2 wheels in the direction of the third, the latter wheel gets raised into the air. I used the ...
7 views

How to programatically set joint friction torque?

I have a car model in Gazebo. Each of the 4 wheels has a continuous joint with friction torque in the urdf file. I want to set the friction torque value dynamically in the source code (instead of ...
13 views

Setting friction params

Ok guys, is any of you open to explain this in a simplified matter, or on a specific example? We all usually need friction for wheels; so If you have a wheel, turning on the x direction. You would ...
7 views

How does ODE determine contact points in Gazebo?

I was looking at the contact points for the Atlas in the DRCsim package. Each foot has 4 contact points at each vertex of the rectangle. I'd like to know how these points are determined. I've tried ...
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Explain Gazebo friction coefficients <mu> and <mu2>?

I'm having a tough time grasping the difference between "mu" and "mu2". The friction tutorial says that: "mu" is the Coulomb friction coefficient for the first friction ...
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Why ground_plane has mu 100 mu2 50 if documentation says it's in range [0..1]

Checking out friction parameters trying to solve situations involving grasping and a humanoid walking I ended up with a doubt: If I check mu and mu2 parameters from ground_plane in the different sdf ...
9 views

Are mu and mu2 in the direction of the world frame, or collision frame?

I'm trying to do model some basic 4-wheel robots, and they having difficulty turning. My first attempt was to mess with <mu> and ...
43 views

How to set friction direction in gazebo

Hello, I am trying to set different friction coefficients in the different x-y link direction. For that i am using the <mu> , <mu2> and <fdir1> ...
11 views

What do the friction coefficients mean and why are they so large in the DRCSim Atlas URDF files?

I've been looking through the URDF specifications of the Atlas robot from DRC Sim. I noticed that there are two mu values and that they are quite large for what I would expect for a coefficient of ...