Fundamental performance of a 6 wheeled off-road vehicle "HELIOS-V"

We present the development of the "HELIOS" series off-road vehicles and powered wheelchairs that are able to ascend and descend stairs. In this paper, we describe a 6-wheeled vehicle "HELIOS-V", which is equipped with 4 low-pressure tires on the outside and 2 high-pressure tires on the inside. This vehicle has two continuously variable transmissions to change velocity and direction of locomotion. We intend to use low-pressure tires for ascending and descending obstacles such as stairs because of their ability to produce high grip forces on the edges of obstacles. In this paper, we describe the design of the "HELIOS-V", characteristics of the continuously variable transmission, reduction of the driving resistance using the low and high pressure tires and the difficulties while ascending and descending stairs.