Optimum steering input determination and path-tracking of all-wheel steer vehicles on uneven terrains based on constrained optimization

In this paper we propose a framework for optimum steering input determination of all-wheel steer vehicles (AWSV) on rough terrains. The framework computes the steering input which minimizes the tracking error for a given trajectory. Unlike previous methodologies of computing steering inputs of car-like vehicles, the proposed methodology depends explicitly on the vehicle dynamics and can be extended to vehicle having arbitrary number of steering inputs. A fully generic framework has been used to derive the vehicle dynamics and a non-linear programming based constrained optimization approach has been used to compute the steering input considering the instantaneous vehicle dynamics, no-slip and contact constraints of the vehicle. All Wheel steer Vehicles have a special parallel steering ability where the instantaneous centre of rotation (ICR) is at infinity. The proposed framework automatically enables the vehicle to choose between parallel steer and normal operation depending on the error with respect to the desired trajectory. The efficacy of the proposed framework is proved by extensive uneven terrain simulations, for trajectories with continuous or discontinuous velocity profile.

[1]  Fumio Harashima,et al.  A position control differential drive wheeled mobile robot , 2001, IEEE Trans. Ind. Electron..

[2]  Jeffrey J. Biesiadecki,et al.  Athlete: A cargo handling and manipulation robot for the moon , 2007, J. Field Robotics.

[3]  R. Rajagopalan,et al.  Comparative study of velocity and computed torque control schemes for a differentially driven automated vehicle , 1996, Proceedings of IEEE International Conference on Robotics and Automation.

[4]  R. M. DeSantis Path-tracking for car-like robots with single and double steering , 1995 .

[5]  R. C. Coulter,et al.  Implementation of the Pure Pursuit Path Tracking Algorithm , 1992 .

[6]  Karl Iagnemma,et al.  Kinematic analysis and control of an omnidirectional mobile robot in rough terrain , 2007, 2007 IEEE/RSJ International Conference on Intelligent Robots and Systems.

[7]  K. Madhava Krishna,et al.  Planning stable trajectory on uneven terrain based on Feasible Acceleration Count , 2011, IEEE Conference on Decision and Control and European Control Conference.

[8]  Majura F. Selekwa,et al.  Path tracking control of four wheel independently steered ground robotic vehicles , 2011, IEEE Conference on Decision and Control and European Control Conference.

[9]  Frédéric Plumet,et al.  Motion kinematics analysis of wheeled-legged rover over 3D surface with posture adaptation , 2010 .

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