General Thoughts
I have always been fascinated by Stewart platforms and their use in simulators and racing games. For this project, I want to build a scaled-down prototype that can simulate the motion of a boat moving through the ocean.
I am still learning the hardware side of things, but I am excited to dive in. My main focus is the pipeline between Unity and the Arduino. If I can get a close approximation of the motion mapping working, that will be a success in itself. Realistic fluid dynamics and hard-surface physics are well beyond the scope of this project, but I think there is a lot to learn by experimenting and building a prototype.
This will be my first project that brings code, hardware, and simulation together. I plan to start with a scaled version and enjoy the process of designing it.
I also plan to write more posts that explore each part of the project in more detail, then update the main project page as I make progress.
Motion Control Considerations
The simulation will run in the Unity engine.
Motion mapping will be controlled with an Arduino.
A 6-actuator Stewart platform will provide 6 DOF motion using inverse kinematics.
Washout filtering will help keep motion within physical limits and avoid singularities.
A physical kill-switch will be included for safety.
Considerations
Control Pipeline
Data transformation
IK solving, especially the best and fastest method
Motion filtering and scaling
Calibration and default pose
Communication
Communication method
Latency
Throughput and data size
Dropouts and reconnection
Error tolerance and handling
Hardware
Actuator type
Cost
Material
Complexity
Scalability
Power
Safety
Open Questions
Which Arduino is best suited for this project?
What actuators are needed for the arms?
Which ocean simulation package in Unity is the most robust and practical?
Are there design caveats that apply to a scaled prototype but not to the full-scale version, and vice versa?
What is the best way to reduce debugging time and improve profiling?
Next Steps
Create a project proposal for the Projects section.
Produce a bill of materials for the hardware.
Experiment with Unity water and boat physics.
Research Stewart platforms and parallel platforms through papers, videos, and other projects online.
See you in the next one!