A new hybrid micro vehicle called the hopping rotochute has been developed to robustly explore rough and complex terrain. Unlike other jumping robots, the vehicle traverses an area by intermittently powering a small coaxial rotor system that allows the device to hop over obstacles of various shapes and sizes. A movable internal mass controls the vehicle's direction of travel, and the exterior shape and low mass center allow the vehicle to passively reorient itself to an upright attitude when in contact with the ground. This paper presents a dynamic model of the hopping rotochute used to assess the basic flight performance of the vehicle. The experimental methods used to estimate model parameters are described and comparisons between measured and simulated motion are presented. Basic flight performance predicted by dynamic simulation is reported, including maneuverability, jumping performance, and total range. The simulated results indicate that the hopping rotochute is capable of surmounting larger obstacles than current hoppers while being able to navigate with the use of a movable internal mass.

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.

The effectiveness of open-box micro air vehicles to deliver light, small payloads of high importance to specific ground coordinates is investigated through dynamic simulation. The open box exhibits interesting and varied flight dynamic behavior as key design parameters are changed. For example, the open box can achieve a coning behavior, a corkscrewing behavior, or glide much like a conventional aircraft to the ground by merely shifting the mass center location. The four rear flaps of the air vehicle can be used to control the box and affords the aircraft greater control authority than dispersion caused by typical atmospheric winds. This control mechanism can also be used as a braking system, which can greatly arrest the descent rate before ground impact. These dynamic qualities make the open box a promising airdrop vehicle which can cut through atmospheric winds towards the target before decelerating and gently landing.

Strickly speaking, most autonomous parafoil and payload aircraft possess only lateral control, achieved by right and left parafoil brake deflection. An innovative new technique to achieve direct longitudinal control through dynamic incidence angle changes is reported. Addition of this extra control channel requires simple rigging changes and an additional servo actuator. The ability of dynamic incidence angle to alter the glide slope of a parafoil and payload aircraft is demonstrated through a flight test program with a micro parafoil system. Results from the flight test program are synthesized and integrated into a 6 degreeof-freedom simulation. The simulation model is subsequently used to assess the utility of glide slope control to improve autonomous flight control system performance. Through Monte Carlo simulation, impact point statistics with and without glide slope control indicate that dramatic improvements in impact point statistics are possible using direct glide slope control.

3 2 1 0 , , , q q q q : Quaternion orientation parameters of box. w v u , , : Components of velocity vector of mass center in body reference frame. r q p , , : Components of angular velocity vector in body reference frame. Z Y X , , : Total applied force components in body reference frame. N M L , , : Total applied moment components about mass center in body reference frame. A A A w v u , , : Relative aerodynamic velocity components of mass center in body reference frame. A V : Magnitude of relative aerodynamic velocity vector of mass center.

3 2 1 0 , , , q q q q : Quaternion orientation parameters of box. w v u , , : Components of velocity vector of mass center in body reference frame. r q p , , : Components of angular velocity vector in body reference frame. Z Y X , , : Total applied force components in body reference frame. N M L , , : Total applied moment components about mass center in body reference frame. A A A w v u , , : Relative aerodynamic velocity components of mass center in body reference frame. A V : Magnitude of relative aerodynamic velocity vector of mass center.

A simple dynamic allocation algorithm is described for queuing variable length messages in memory. The algorithm makes use of the ability of many operating system to increase and decrease available memory as required. Some results describing its efficiency are presented.