Stabilization and path following of a single wheel robot

We have developed a single wheel, gyroscopically stabilized robot. This is a novel concept for a mobile robot that provides dynamic stability for rapid locomotion. The robot is a sharp-edged wheel actuated by a spinning flywheel for steering and a drive motor for propulsion. The spinning flywheel acts as a gyroscope to stabilize the robot and it can be steered by tilting. This robot is nonholonomic in nature, underactuated and inherently unstable in the lateral direction. In this paper, we first develop a three-dimensional (3-D) nonlinear dynamic model and investigate the dynamic characteristics of the robot. We conduct simulations and real-time experiments to verify the model. Both simulations and experiments show that the flywheel has a significant stabilizing effect on the robot. Then, we can decouple the longitudinal and lateral motions of the robot by linearization. We propose a linear state feedback to stabilize the robot at different lean angles, so as to control the steering velocity of the robot indirectly, because the robot steers only by leaning itself to a predefined angle. For the task of path following, we design a controller for tracking any desired straight line without falling. In the controller, we first design the linear and steering velocities for driving the robot along the desired straight line by controlling the path curvature. We then apply the linear state feedback to stabilize the robot at the predefined lean angle such that the resulting steering velocity of the robot converges to the given steering velocity. This work is a significant step toward fully autonomous control of such a dynamically stable but statically unstable system.

[1]  R. McGhee,et al.  The adaptive suspension vehicle , 1986, IEEE Control Systems Magazine.

[2]  Vijay Kumar,et al.  Control of Mechanical Systems With Rolling Constraints , 1994, Int. J. Robotics Res..

[3]  D. R. Freitag.  History of wheels for off-road transport , 1979 .

[4]  Jerry H. Ginsberg,et al.  Advanced Engineering Dynamics , 1988 .

[5]  Fumio Miyazaki,et al.  A stable tracking control method for a non-holonomic mobile robot , 1991, Proceedings IROS '91:IEEE/RSJ International Workshop on Intelligent Robots and Systems '91.

[6]  N. McClamroch,et al.  Stabilization and asymptotic path tracking of a rolling disk , 1995, Proceedings of 1995 34th IEEE Conference on Decision and Control.

[7]  P. R. Klarer.  Recent Developments in the Robotic All Terrain Lunar Exploration Rover (RATLER) Program , 1993 .

[8]  D.W. Vos,et al.  Dynamics and nonlinear adaptive control of an autonomous unicycle: theory and experiment , 1990, 29th IEEE Conference on Decision and Control.

[9]  I. C. Holm,et al.  Articulated, wheeled off-the-road vehicles , 1970 .

[10]  Ilya Kolmanovsky,et al.  Application of Integrator Backstepping to Nonholonomic Control Problems , 1995 .

[11]  Fariba Fahroo,et al.  A new line tracking method for nonholonomic vehicles , 1997, Proceedings of International Conference on Robotics and Automation.

[12]  A. V. Lensky,et al.  Control of autonomous motion of two-wheel bicycle with gyroscopic stabilisation , 1998, Proceedings. 1998 IEEE International Conference on Robotics and Automation (Cat. No.98CH36146).

[13]  P. S. Sologub,et al.  Small Marsokhod configuration , 1992, Proceedings 1992 IEEE International Conference on Robotics and Automation.

[14]  Arthur E. Bryson,et al.  Design and test of a computer-stabilized unicycle , 1988 .

[15]  Claude Samson,et al.  Time-varying Feedback Stabilization of Car-like Wheeled Mobile Robots , 1993, Int. J. Robotics Res..

[16]  N. H. Getz.  Control of balance for a nonlinear nonholonomic non-minimum phase model of a bicycle , 1994, Proceedings of 1994 American Control Conference - ACC '94.

[17]  Kazuo Yamafuji,et al.  Postural stability of a human riding a unicycle and its emulation by a robot , 1997, IEEE Trans. Robotics Autom..

[18]  O. J. Sørdalen,et al.  Exponential control law for a mobile robot: extension to path following , 1992, Proceedings 1992 IEEE International Conference on Robotics and Automation.

[19]  Yangsheng Xu,et al.  Dynamic control and coupling of a free-flying space robot system , 1994, J. Field Robotics.

[20]  Eric Krotkov,et al.  Ambler: Performance of a six-legged planetary rover☆ , 1992 .

[21]  Yangsheng Xu,et al.  A single-wheel, gyroscopically stabilized robot , 1996, Proceedings of IEEE International Conference on Robotics and Automation.

[22]  Yangsheng Xu,et al.  Decoupled dynamics and stabilization of single wheel robot , 1999, Proceedings 1999 IEEE/RSJ International Conference on Intelligent Robots and Systems. Human and Environment Friendly Robots with High Intelligence and Emotional Quotients (Cat. No.99CH36289).

[23]  Takashi Tsubouchi,et al.  A development of a new mechanism of an autonomous unicycle , 1997, Proceedings of the 1997 IEEE/RSJ International Conference on Intelligent Robot and Systems. Innovative Robotics for Real-World Applications. IROS '97.