Fukushima Lab

JAPANESE


Terrain Adaptive Crawler Vehicle "HELIOS-VI"	BACK TO ROBOTS

(2000-)The new Helios VI (Fig. 1), the most recently designed version, is a tracked vehicle that can easily climb stairs by the use of two active arms. It has an asymmetric shape as shown in Fig. (3). One arm is basically used to put in contact the crawlers with the first step and to assist the vehicle motion.

The other arm adjusts the payload position, changing the posture of the carrier. The acceleration and the translation motion of the carrier are controlled in order to maintain a constant posture of the chassis. (Fig. 2)

For steering, Helios VI requires low energy because the center of gravity is principally positioned in the front part of the vehicle (the chassis’ own the weight on the shaft of the driving pulley) therefore the turning resistance is significantly reduced (Fig. 3).

A commercial rubber crawler has been used since, as in the case of TAQT Carrier, when a minimum amount of payload is applied on the carrier, it shows an outstanding performance on stairs. Helios VI uses a continuously variable transmission system. The gear ratio can be changed between 2 (for flat terrains) and 30 for climbing motion.

Making use of several simulations of Helios VI vehicle (Fig. 4), in order to automate stairs ascending and descending a control system has been developed.

Fig.1 Helios VI

Table.1 Main Specifications of Helios VI

Dimensions Length	1055[mm]
Width	700[mm]
Height	400[mm]
Total mass	85[kg]
Portable load	120[kg] (estimation)
Slope climbing ability	About 40 degrees Slope and Stairs
Velocity	70 [mm/s] (With maximum load) 175 [mm/s] (With no load)
Movable range of the front arm	-90 +90

Fig.2 Helios VI ascending stairs

Fig.3 Position of the Center of Gravity

Fig. 4 Stairs climbing simulation

Fig. 5 Several cooperating units

References:

S. Hirose, E. Fukushima, R. Damoto, and H. Nakamoto, “Design of terrain adaptive versatile crawler vehicle HELIOS-VI,” IEEE Int. Conference on Intelligent Robots and Systems, pp. 1540?1545, Nov. 2001.
Edwardo F. Fukushima, Hideichi Nakamoto, Riichiro Damoto and Shigeo Hirose, “Optimal Load-Sensitive Control for Mobile Robots Equipped with Continuously Variable Transmissions,” IEEE Int. Conference on Intelligent Robots and Systems, pp. 476-481, Nov. 2001.