(1994- ). Japan has many mountainous areas, and the construction of transportation facilities such as highways and railways is carried out frequently. At present, workers have to climb up the slope to engage in the task with their facing to the danger, shown in Photo 1.
To improve these circumstances, we have started to develop a mobile robot which can play a role as a mobile platform on the rugged and steep slope under construction. For the basic structure, we selected the walking style, because it can avoid obstacles and the leg can be also used as a powerful manipulator. And we adopted a quadruped, because four is the minimum number of legs to achieve a statically stable walk.
In the future, up to the construction site, we'll make the robot walk by itself, but on the steep slope it will be suspended a pair of wires, just like Fig.1 .
To realize this project, it is crucial to design both the mechanism and a gait maintaining the stability. As for the mechanism, we adopted Rocker Bogie Sole ( Photo 2 ) to avoid slipping and the extensible leg to set the center of gravity higher up the slope.
As for the gait, the intermittent crawl gait, which cam which enables the quadruped walking robot to move more stably than the crawl gait, is introduced( Fig.2 ). TITAN VII ( Photo 3 ) developed in this way could walk 15 degree slope by itself, and could climb 70 degree slope with its body supported by wires( Photo 4 ). The velocity at that time was kept at 177[mm/s] with its weight of 60[kgf].
At present, Time-Of-Flight Laser Range Finder has been installed (Photo 5) in order to measure elevation of the terrain and to navigate, and step over obstacles.
Photo.1 Workers performing construction tasks on a steep slope
Fig.1 Future application
Fig.2 Comparison of motion and stability between the crawl gait and the intermittent crawl gait
Photo.2 Rocker Bogie Sole which can adapt itself to rough terrain
Photo.3 Over all view of TITAN VII climbing up 30 degree with its downhill legs extended<
Photo.4 TITAN VII climbing 70 degree slope
Fig.3 Dual drive mechanism of the up/down drive axle
References:
Hideyuki Tsukagoshi,Shigeo Hirose,Kan Yoneda;Maneuvering Operations of a Quadruped Walking Robot ,Advanced Robotics,11,4,pp.359-375(1997)
Shigeo Hirose,Kan Yoneda,Hideyuki Tsukagoshi; TITAN VII:Quadruped Walking and Manipulating Robot on a Steep Slope,Proc.Int.Conf.on Robotics and Automation,Albuquerque,New Mexico,pp.494-500(1997)
Doi, Hirose; 3D Visual Information Processing and Gait Controlof a Quadruped Robot, Journal of Robotics and MechatronicsCVol.15, No.3.
Quadruped Walking Machine to Climb Up Slopes "TITAN VII"
PAGE TOP
