Abstract
Mechanical problems of the terrain-adaptable robot vehicle in practical use are discussed.
Recently we developed a scale model of a robot vehicle named “Transformable crawler vehicle”. This vehicle has an ability to actively adapt to terrain variations by changing the shape of its crawler units. But its size is too small to run over the actual size stairs. Moreover, it has some points to be improved for practical use. Therefore, we have developed a full scale 2nd-prototype vehicle in order to improve and refine the mechanism.
The volume of this vehicle is about 4.3 times larger than prototype, but the weight is only 2.5 times heavier than that of the prototype. This weight reduction is achieved by using the CFRP, and the structure design improvement.
This machine has an passive adaptability to the terrain variation by ground contact force equarizing mechanism. This mechanism is effective to prevent from slip down when climbing up and down the stairs. It has also turning resistance reducing mechanism by shorten the ground contact length by pushing down the auxiliary wheels. This mechanism can reduce the turning resistant force to 53%. It has also specially designed transmission in order to climb up steep stairs and run fast on flat floor. This vehicle have run on flat surface at a speed of 2.2km/h, and climbed up actual stairs of 39.3° inclination, 203mm step at a speed of 0.44km/h.
