An implementation of omni directional vehicle controller based on offset diff drive mechanism.

Based on the paper:

Masayoshi Wada, etal. Omnidirectional Holonomic Mobile Robot Using Nonholonomic Wheels IEEE International Conference on Intelligent Robots and Systems (IROS '95), 446-453, 1995.

和田正義 他 双輪キャスタ型駆動機構を用いたホロノミック全方向移動ロボット 日本ロボット学会誌 Vol.18 No.8, pp.1166-1172, 2000. https://www.jstage.jst.go.jp/article/jrsj1983/18/8/18_8_1166/_pdf

Patent has been expired in 2015/12/11 https://patents.google.com/patent/US5924512A/en

See following notebook for additional details on the formalization:

https://nbviewer.jupyter.org/github/devrt/offset-diff-drive-controller/blob/master/offset-diff-drive-dynamics.ipynb