The circular inverted pendulum  adopts an   open architecture control solution with expandible  experimental modules. With   the circular motion base platform, it is easy to be configured to satisfying    various needs for control teaching and research. Namely:
 
                            (i) Circular   one-stage inverted pendulum 
                            (ii) Circular two-stage serial inverted pendulum 
                            (iii) Circular two-stage parallel inverted pendulum
 
                            (iv) Combined   serial & parallel inverted pendulums of three- and four-stages