Institut des Systèmes Intelligents
et de Robotique

Complios, an hybrid and compliant mobile robot

With a 80 cm length and an initial height of 34 cm, the Complios is designed to move on uneven and unknown terrains. To this end, it stands on four wheels that are linked to the chassis via partially actuated legs. These legs are compliant : they deform under the action of external forces and thus allow the robot to "feel" the relief. By means of a series elastic actuation, which combines motorization and springs, the Complios spontaneously adapts its configuration according to the ground geometry on which it is rolling. It is then able to advance without any prior knowledge on the terrain, while controlling its stability as well as the load distribution on the different wheels.
The Complios' legs are also design so as to distinguish the horizontal internal stresses induced by the presence of surrounding obstacles. Therefore, the observation of its structure deformations allows the robot to automatically deduce how the actuation should be modified in order to overcome the difficulties. It is thus able to react to unanticipated obstacles while relying solely on proprioceptive data provided by its encoders and its inertial unit. The posture control, as well as the redundancy of the actuation, then provide various solutions to deal with each situation that can be encountered.

Related publications :

Bouton, A. and Grand, Ch. and Ben Amar, F. (2017). Obstacle Negotiation Learning for a Compliant Wheel-on-Leg Robot,
Proceedings of IEEE Int. Conference on Robotics and Automation ICRA 2017.

Bouton, A. and Grand, Ch. and Ben Amar, F. (2016). Design of a Compliant Wheel-Legged Robot,
Proceedings of the 19th Int. Conference on Climbing and Walking Robots CLAWAR 2016.

Bouton, A. and Grand, Ch. and Ben Amar, F. (2016). Motion control of a compliant wheel-leg robot for rough terrains crossing,
Proceedings of IEEE Int. Conference on Robotics and Automation ICRA 2016.

Bouton, A. and Grand, Ch. and Ben Amar, F. (2016). Véhicule autonome compliant et procédé de commande associé, Patent No 165806.

Agile Fast Rover : SPIDO

The suspension design has ability to control its roll angle and its roll stability, by using a hydraulic cylinder that can shift the center of gravity and decrease then the lateral load transfer during cornering, especially at high speed, in the same manner than a moto racer when leaning inside a turn. The roll angle controller is based also on a linear MPC, ensuring anticipation to path curvature changes and future setpoint changes.

Spido robot is a fast all-terrain mobile robot with four-wheel drive and steering (4WDS). It can reach 12 m/s speed. It weighs about 700 kg. It is equipped with 4 dual wishbone independent suspensions and 2 active anti-roll bars. A Real Time Kinematic GPS (RTK-GPS) provides an accurate localization in real-time of the platform with respect to a reference station, and an IMU (Inertial Measurement Unit) gives orientation angles of the platform. A 3D LIDAR allows to perceive the environment and to identify dynamic or static obstacles. This platform is funded thanks to Robotex grants which is an Equipex national projet dedicated to investment (PIA Projet d'Investissement d'Avenir).

Related publications :

Krid, M. Ben Amar, F and Lenain, R, A new explicit dynamic path tracking controller using generalized predictive control, International Journal of Control, Automation and Systems, vol. 15, no. 1, pp.303-314, 2017

Krid, M and Ben Amar, F, Design and control of an active anti-roll system for a fast rover, Intelligent Robots and Systems (IROS), 2011 IEEE/RSJ International Conference

Krid, M. and Zamzami, Z. and Ben Amar, F. (2015). Design of an active device for controlling lateral stability of fast mobile robot. Robotica. Vol 34 No 11 Pages 2629–2651.