Motion planning for all-terrain
We address modeling and global motion planning issues for an autonomous
wheeled mobile robot moving on an uneven three-dimensional terrain. The
basic problem we address is: starting from a given initial configuration
of the robot in contact with the terrain, find a feasible trajectory (configurations/velocities
and the control torques to be applied on the robot wheels) that moves the
robot toward a given desired configuration. The focus in our work is particularly
on the issue of dealing with dynamic and wheel/ground interaction constraints.
We believe that such an issue is fundamental for characterizing feasible
motions in the case of an all-terrain vehicle.
We have developed a suitable multi-level planning algorithm to deal with
the intrinsic characteristics of all-terrain locomotion. A key feature
of our approach is that it incorporates appropriate physical models to
cope with the task dynamics in the motion planning paradigm. The planner
is based on a two-level scheme. The high level considers a simplified 2D
instance of the motion task and searches a subset of the configuration
space of the robot in order to generate nominal sub-goals through which
the robot is steered. The local level solves for continuous feasible trajectories
and actuator controls to move the robot between neighboring sub-goals in
the presence of the entire task constraints. To the best of our knowledge,
this is the first implemented planner that solves for feasible trajectories
to be performed by a wheeled vehicle on quite complex terrains. Simulation
results are presented for the case of a six-wheeled articulated robot as
shown in the presented figures.
Recent related publications:
- M. Cherif, ``Motion Planning for All-Terrain Vehicles: A Physical
Modeling Approach for Coping with Dynamic and Contact Interaction Constraints'',
IEEE Transactions on Robotics and Automation, vol. 15, no. 2,
pages 202-218, April 1999 (regular paper).
- M. Cherif, "Kinodynamic Motion Planning for All-Terrain
Wheeled Vehicles", in Proceedings of the IEEE Int. Conference
on Robotics and Automation, Detroit, Michigan, USA, May, 1999.
Please, send your comments to Moez.Cherif@inrialpes.fr