Title :
Wheeled robot with movable center of mass for traversing over rough terrain
Author :
Nakamura, Sousuke ; Faragalli, Michele ; Mizukami, Noriaki ; Nakatani, Ichiro ; Kunii, Yasuharu ; Kubota, Takashi
Author_Institution :
ISAS/JAXA, Sagamihara
fDate :
Oct. 29 2007-Nov. 2 2007
Abstract :
Planetary exploration requires rovers to perform a variety of challenging tasks autonomously. In order to complete relevant scientific mission, these rovers need to overcome difficulty for rough terrain traversing by "online methods". This paper discusses an idea that utilizes a rover mobile center of mass in order to aid in traversing rough terrain. According to vehicle pitch angle and contact angles, the rover recalculates the optimal position for the center of mass to minimize the indicator defined by two factors : the wheel driving force over the wheel normal force (adhesion coefficient) and tip-over stability angle (stability coefficient). Two innovative approaches are developed in this paper. The first one is that the authors defines easily comprehensible two factors, adhesion and stability coefficients for traversability indicator and proposes a method to calculate optimal center of mass position. The second one is that in the case of four-wheels drive, the relation between the front wheel and the rear wheel adhesion coefficient is easily solved and the best case for giving the driving forces can be solved as force making the front and the rear wheel adhesion coefficient equal. The authors call this "optimal force distribution method". Finally, this paper shows some simulation results for traversing rough terrain that compute the optimal center of mass while traversing the terrain.
Keywords :
aerospace robotics; mobile robots; planetary rovers; stability; movable mass center; optimal force distribution method; planetary exploration; rear wheel adhesion coefficient; rough terrain traversing; rover mobile mass center; scientific mission; tip-over stability angle; wheel driving force; wheel normal force; wheeled robot; Adhesives; Intelligent robots; Mars; Mobile robots; NASA; Orbital robotics; Space exploration; Stability; Weight control; Wheels;
Conference_Titel :
Intelligent Robots and Systems, 2007. IROS 2007. IEEE/RSJ International Conference on
Conference_Location :
San Diego, CA
Print_ISBN :
978-1-4244-0912-9
Electronic_ISBN :
978-1-4244-0912-9
DOI :
10.1109/IROS.2007.4399168