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icub-tech-iit / ergocub-gazebo-simulations

Repository containing the models and the simulations for ergoCub
BSD 3-Clause "New" or "Revised" License
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Strange IMU Behaviour in Simulation #38

Closed SimoneMic closed 2 years ago

SimoneMic commented 2 years ago

Hello,

Using stickBot in simulation, reading straight from the port /icubSim/chest/inertials/measures:o I have noticed some things that I can't explain. Example of a message with the robot staying still:

(((-0.000261648547432980632665 0.000386437616020565775487 -6.33732246059674829246e-06) 4221.79699999999957072)) 
(((0.0134758698668982629387 -9.79686681490665201011 0.245724967233435981351) 4221.79699999999957072)) 
(((0.0 0.0 0.0) 4221.79699999999957072)) 
(((1.44258615603545758965 -4.1081595871458080893 -0.0789977909900776154029) 4221.79699999999957072)) 
() () () () () ()

First triplet should be orientation RPY angles, the second one is for accelerations, then gyroscope and magnetometer.

  1. The gyroscope readings are all zero, and they don't change even when the robot is moving.
  2. The gravity acceleration is on the Y axis.

Furthermore, when I command the robot to turn on itself, the orientation on the yaw angle follow a sinusoid with a different period and amplitude. The following graph is a comparison with the ground truth yaw orientation (from gazebo). imu_graph

Blue is the ground truth.

Note: I have changed the IMU placement in the urdf file, to make it follow the ENU convention.

Nicogene commented 2 years ago

Hi @SimoneMic,

this behavior is happening also using iCubGazeboV3? Because in theory the imu orientation should be the same

SimoneMic commented 2 years ago

Hi,

I've tested with iCubGazeboV3 and the behavior is the same:

(((-0.0328292260296344853843 0.148951018372791843536 -0.0819835359097082494451) 49.59100000000000108)) 
(((0.0889226401005454580861 -9.65709876495395391771 -0.0539563243637438683109) 49.59100000000000108)) 
(((0.0 0.0 0.0) 49.59100000000000108)) 
(((-0.287830912787782944307 -0.00233404220161263732322 -0.0046476064837987912659) 49.59100000000000108)) () () () () () ()
Nicogene commented 2 years ago

I would move this issue in or gazebo-yarp-plugins or maybe better icub-models, what do you think about @traversaro ?

traversaro commented 2 years ago

Ok!

traversaro commented 2 years ago

I think the best place is icub-models @SimoneMic can you open an issue there? Unfortunatly we can't transfer directly issues that belong to different organizations.

SimoneMic commented 2 years ago

Ok, I will copy-paste this in icub-models. Thanks!

Closing.