Hybrid feedback path following for robotic walkers via bang-bang control actions

This paper presents a control algorithm conceived to guide a robotic walking assistant along a planned path using electromechanical brakes. The device has been modelled as a Dubins' car, a wheeled vehicle that moves only forward in the plane and constrained by a lower bounded turning radius. In order to reduce the hardware requirements as much as possible, so as to reduce the costs, we work with limited sensory information, so the classic modulated braking guidance cannot be implemented. As a consequence, the vehicle has a very limited set fixed turning radius manoeuvres ruled by a hybrid controller based on three discrete states: go straight, turn right and turn left. Despite of these limitations and in order to ensure a gentle and natural convergence of the user to the planned path, the robot approaches the path with an orientation that depends on its position and that guarantees a continuous curvature of the tracked path. Results are validated using extensive simulations.

[1]  Axel Legay,et al.  Efficient customisable dynamic motion planning for assistive robots in complex human environments , 2015, J. Ambient Intell. Smart Environ..

[2]  Lionel Lapierre,et al.  Nonlinear Path Following Control of an AUV , 2007 .

[3]  Antonio Bicchi,et al.  Optimal feedback control for route tracking with a bounded-curvature vehicle , 2000, Proceedings 2000 ICRA. Millennium Conference. IEEE International Conference on Robotics and Automation. Symposia Proceedings (Cat. No.00CH37065).

[4]  Giuseppe Oriolo,et al.  Feedback control of a nonholonomic car-like robot , 1998 .

[5]  C. Samson.  Control of chained systems application to path following and time-varying point-stabilization of mobile robots , 1995, IEEE Trans. Autom. Control..

[6]  Jean-Paul Laumond,et al.  Robot Motion Planning and Control , 1998 .

[7]  Davor Hrovat,et al.  Vehicle steering intervention through differential braking , 1995, Proceedings of 1995 American Control Conference - ACC'95.

[8]  Luigi Palopoli,et al.  Unicycle steering by brakes: A passive guidance support for an assistive cart , 2013, 52nd IEEE Conference on Decision and Control.

[9]  Kazuhiro Kosuge,et al.  Development of passive type double wheel caster unit based on analysis of feasible braking force and moment set , 2011, 2011 IEEE/RSJ International Conference on Intelligent Robots and Systems.

[10]  Carlos Canudas de Wit,et al.  Exponential control law for a mobile robot: extension to path following , 1993, IEEE Trans. Robotics Autom..

[11]  Jean-Paul Laumond,et al.  An Optimality Principle Governing Human Walking , 2008, IEEE Transactions on Robotics.

[12]  A. Bicchi,et al.  Path-following with a bounded-curvature vehicle: a hybrid control approach , 2005 .

[13]  Luigi Palopoli,et al.  Design and performance analysis of an indoor position tracking technique for smart rollators , 2013, International Conference on Indoor Positioning and Indoor Navigation.

[14]  Anselmo Frizera,et al.  A review of the functionalities of smart walkers. , 2015, Medical engineering & physics.

[15]  Antonio Bicchi,et al.  Closed loop steering of unicycle like vehicles via Lyapunov techniques , 1995, IEEE Robotics Autom. Mag..

[16]  Jean-Paul Laumond,et al.  From human to humanoid locomotion—an inverse optimal control approach , 2010, Auton. Robots.

[17]  Antonio Bicchi,et al.  Path tracking control for Dubin's cars , 1996, Proceedings of IEEE International Conference on Robotics and Automation.

[18]  Kazuhiro Kosuge,et al.  Motion Control of Passive Intelligent Walker Using Servo Brakes , 2007, IEEE Transactions on Robotics.

[19]  Luigi Palopoli,et al.  Passive robotic walker path following with bang-bang hybrid control paradigm , 2016, 2016 IEEE/RSJ International Conference on Intelligent Robots and Systems (IROS).

[20]  Luigi Palopoli,et al.  A passive guidance system for a robotic walking assistant using brakes , 2015, 2015 54th IEEE Conference on Decision and Control (CDC).

[21]  Antonio M. Pascoal,et al.  Adaptive, non-singular path-following control of dynamic wheeled robots , 2003, 42nd IEEE International Conference on Decision and Control (IEEE Cat. No.03CH37475).

[22]  Ulises Cortés,et al.  Assistive technologies for the new generation of senior citizens: the SHARE-it approach , 2010, Int. J. Comput. Heal..

[23]  Zhong-Ping Jiang,et al.  Saturated stabilization and tracking of a nonholonomic mobile robot , 2001 .

[24]  Axel Legay,et al.  Motion planning in crowds using statistical model checking to enhance the social force model , 2013, 52nd IEEE Conference on Decision and Control.

[25]  Luigi Palopoli,et al.  Indoor Positioning of a Robotic Walking Assistant for Large Public Environments , 2015, IEEE Transactions on Instrumentation and Measurement.