Off-road mobile robots control: An accurate and stable adaptive approach

Automation in outdoor applications at high speed (such as farming, surveillance, etc.) requires the highly accurate control of mobile robots, taking into account natural ground characteristics, in order to preserve both motion accuracy and robot stability. To meet such expectations, advanced control laws must be developed. In previous studies, adaptive and predictive control algorithms, based on both an extended kinematic and a dynamic representation, have been proposed to specifically address path tracking for such robots. However, even if high accuracy path tracking can be attained, such control laws do not enable roll-over situations to be avoided. This paper therefore addresses the prevention of off-road mobile robot roll-over as well as path tracking. In order to meet this aim, a stability metric, depending on a dynamic model, is computed and sliding phenomena are accounted for via a mixed observer (a multi-model observer, mixing kinematic and dynamic modelling). The steering angle is then controlled by the path tracking algorithm, and robot longitudinal speed may be limited to ensure safe motion. More precisely, the robot velocity leading to a critical value of the stability metric is computed via Predictive Functional Control (PFC), and this constitutes the speed control set point when inferior to the desired robot speed. The capabilities of the proposed approach are demonstrated and discussed thanks to full scale experimentation.

[1]  Philippe Bidaud,et al.  Dynamic Analysis of Off-Road Vehicles , 1995, ISER.

[2]  Urbano Nunes,et al.  Trajectory planning and sliding-mode control based trajectory-tracking for cybercars , 2007, Integr. Comput. Aided Eng..

[3]  Maria Letizia Corradini,et al.  Experimental testing of a discrete-time sliding mode controller for trajectory tracking of a wheeled mobile robot in the presence of skidding effects , 2002, J. Field Robotics.

[4]  Benoît Thuilot,et al.  Mobile robot control on uneven and slippery ground: An adaptive approach based on a multi-model observer , 2012, 2012 IEEE/RSJ International Conference on Intelligent Robots and Systems.

[5]  Danwei Wang,et al.  Maneuverability and path following control of wheeled mobile robot in the presence of wheel skidding and slipping , 2010, J. Field Robotics.

[6]  Hans B. Pacejka,et al.  Tire and Vehicle Dynamics , 1982 .

[7]  C. Samson,et al.  Trajectory tracking for unicycle-type and two-steering-wheels mobile robots , 1993 .

[8]  Jürgen Ackermann,et al.  Advantages Of Active Steering For Vehicle Dynamics Control , 1999 .

[9]  Philippe Bidaud,et al.  Stabilization algorithm for a high speed car-like robot achieving steering maneuver , 2008, 2008 IEEE International Conference on Robotics and Automation.

[10]  Alessandro Astolfi,et al.  Path-tracking of a tractor-trailer vehicle along rectilinear and circular paths: a Lyapunov-based approach , 2004, IEEE Transactions on Robotics and Automation.

[11]  Maarouf Saad,et al.  A higher level path tracking controller for a four-wheel differentially steered mobile robot , 2006, Robotics Auton. Syst..

[12]  Alonzo Kelly,et al.  Development of a Terrain Adaptive Stability Prediction System for Mass Articulating Mobile Robots , 2003, FSR.

[13]  Jayantha Katupitiya,et al.  Path tracking control of agricultural tractors with compensation for steering dynamics , 2009, Proceedings of the 48h IEEE Conference on Decision and Control (CDC) held jointly with 2009 28th Chinese Control Conference.

[14]  Christophe Debain,et al.  On-line estimation of a stability metric including grip conditions and slope: Application to rollover prevention for All-Terrain Vehicles , 2011, 2011 IEEE/RSJ International Conference on Intelligent Robots and Systems.

[15]  Philippe Martinet,et al.  A new device dedicated to autonomous mobile robot dynamic stability: Application to an off-road mobile robot , 2010, 2010 IEEE International Conference on Robotics and Automation.

[16]  Christophe Debain,et al.  Integrity of an autonomous agricultural vehicle according to the definition of trajectory traversability. , 2010 .

[17]  Roland Siegwart,et al.  Introduction to Autonomous Mobile Robots , 2004 .

[18]  Guy Bessonnet,et al.  Forces acting on a biped robot. Center of pressure-zero moment point , 2004, IEEE Transactions on Systems, Man, and Cybernetics - Part A: Systems and Humans.

[19]  Philippe Martinet,et al.  Multi-model based sideslip angle observer: Accurate control of high-speed mobile robots in off-road conditions , 2009, 2009 IEEE/RSJ International Conference on Intelligent Robots and Systems.

[20]  G. Campion,et al.  Control of Wheeled Mobile Robots Not Satisfying Ideal Velocity Constraints - a Singular Perturbation Approach , 1995 .

[21]  J. Richalet,et al.  Industrial applications of model based predictive control , 1993, Autom..

[22]  Georges Bastin,et al.  Structural properties and classification of kinematic and dynamic models of wheeled mobile robots , 1996, IEEE Trans. Robotics Autom..

[23]  Evangelos Papadopoulos,et al.  A new measure of tipover stability margin for mobile manipulators , 1996, Proceedings of IEEE International Conference on Robotics and Automation.

[24]  A. Rantzer,et al.  Vehicle dynamics control and controller allocation for rollover prevention , 2006, 2006 IEEE Conference on Computer Aided Control System Design, 2006 IEEE International Conference on Control Applications, 2006 IEEE International Symposium on Intelligent Control.

[25]  Philippe Martinet,et al.  High accuracy path tracking for vehicles in presence of sliding: Application to farm vehicle automatic guidance for agricultural tasks , 2006, Auton. Robots.

[26]  Karsten Berns,et al.  Action/perception-oriented robot software design: An application in off-road terrain , 2008, 2008 10th International Conference on Control, Automation, Robotics and Vision.

[27]  Steven C. Peters,et al.  Mobile robot path tracking of aggressive maneuvers on sloped terrain , 2008, 2008 IEEE/RSJ International Conference on Intelligent Robots and Systems.

[28]  Andreas Jacubasch,et al.  Predictive Functional Control - Application to Fast and Accurate Robots , 1987 .

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

[30]  Lv Zhi-qiang.  Safety,Comfort and Convenience Systems for Modern Automobiles , 2007 .

[31]  T D Gillespie,et al.  Fundamentals of Vehicle Dynamics , 1992 .

[32]  Z. Szabo,et al.  The Design of an Integrated Control System in Heavy Vehicles Based on an LPV Method , 2005, Proceedings of the 44th IEEE Conference on Decision and Control.

[33]  Philippe Martinet,et al.  An active anti-rollover device based on Predictive Functional Control: application to an All-Terrain Vehicle , 2009, 2009 IEEE International Conference on Robotics and Automation.