Tuesday, 29 October 2024

 October update


Time for another update on robbie after changing the the drive base to the omni_bot base it showed potential but also a lot of short comings the base was to large to consistently go through corridors the structural integrity was compromised. The base was designed with tighter tolerances and greater rigidity also smaller. We now use stepper motors for the steering system with magnetic encoders. and I2C controller motor drivers with encoders . The motor drivers were from the old design and the python driver was a legacy design. The big change was the odometery function using wheel angles and wheel velocity coupled with a gyro, magnetometer that gave a 20cm accuracy after a 16 meter drive. The successful test of the new omometery node I was able to remover the dead encoder wheel and use ROS nav2 with a MPPI controller in OMNI mode using the nav2 docking server the auto dock works with greater reliability and comes with a undock function all this is mapped the joy stick controller. The python controller was starting to be a bottle neck so I rewrote it in CPP with a noticeable speed improvement. 

this is a video of the the base using navi2 to chase the videographer https://youtu.be/5DKG3iNSfLM

and some build photos






 

 

No comments:

Post a Comment