Performance of a Hopping Rotochute

Abstract

A hybrid micro air/ground vehicle has been developed and is specifically tailored to explore interior spaces with complex terrain. The vehicle, called the hopping rotochute, maneuvers through intricate environments by hopping over or through impeding obstacles. A small coaxial rotor system provides the necessary lift while a moveable internal mass allows directional control. In addition, the low mass center and egg-like exterior shape of the body creates a means to passively reorient the vehicle to an upright attitude when in contact with the ground while protecting the rotating components. This paper examines basic flight performance of the device obtained through a validated simulation. Key parameters such as system weight, rotor speed, internal mass weight and location, as well as battery capacity are varied to explore air vehicle performance characteristics such as single hop height and range, number of hops, and total achievable range. In general, the total achievable range is increased as the internal mass weight, internal mass offset, and battery capacity are increased. For a given system, an optimum rotor speed and pulse width results in the maximum achievable total range for a single battery charge. The sensitivity of the hopping rotochute to atmospheric winds is also investigated and the ability of the device to perform trajectory shaping is shown.