BACKGROUND
Some unmanned aircraft applications for high-speed flight, such as aerial target drones, require a means to launch without a runway. Current methods to address this need include catapults, pneumatic launch rails and rocket-assisted take-off (RATO) systems. The use of a RATO system is often expensive but can be accomplished with a zero-length launch rail that cradles the vehicle and uses a launch footprint nearly the size of the vehicle itself. This method uses rocket motors to not only propel the vehicle forward but also lift the aircraft vertically to a desired flight path angle. Catapult and pneumatic launchers not only have a larger footprint, but they are generally prohibitive for launching multiple vehicles at once, as each vehicle would require a separate launcher that uses a lot of space and costly launch hardware. Also, the catapult and pneumatic launchers typically impart a high g-load to the vehicle structure that can lead to structural fatigue and failure. Conversely, a RATO system imparts a substantially lower g-load and launching multiple aircraft at once simply requires multiple, inexpensive launch rails that have a small footprint. The primary challenge associated with the RATO system is the operating cost and availability of rocket motors. Also, it is difficult to tailor a RATO system design for a specific aircraft with a range of potential vehicle weights and configurations for a variety of potential missions. Therefore, there is a critical need to reduce development cost for low-cost RATO systems.
SUMMARY OF TECHNOLOGY
OSU Researchers have designed a rapid, low-cost development of RATO systems for unmanned aircraft applications. The main components of the demonstrator include a mass simulator, a launch rail trailer, a wireless launch controller and a RATO assembly consisting of a bracket, RATO motor tubes, recovery tubes and rocket motors. The mass simulator is made from readily available material that can be easily reconfigured to mimic the geometry, weight, center of gravity and RATO system interfaces of an intended RATO system application. The launch rail trailer is a commercially available trailer adjusted to cradle and transport the mass simulator and RATO assembly and customize the launch angle. The trailer is equipped with a retention sub-system to inhibit the mass simulator until desired thrust is attained from the RATO rocket motors, at which time a retention shear pin breaks and the vehicle leaves the launch rails. Tethers are used to secure the trailer from moving when rocket exhaust impinges on the trailer structure as the mass simulator leaves the launch rails. The wireless controller consists of a single remote trigger sub-system and a pad box with multiple igniter cables. The trigger sub-system includes an arming mechanism for safety, an indicator to ensure sufficient voltage for operation and a transmitter that broadcasts an encrypted signal. The pad box includes a receiver paired to the trigger transmitter and buttons to verify igniter continuity. The RATO assembly includes a bracket that is easily adjusted to set the RATO rocket angle such that thrust is aligned as desired with the combined vehicle and RATO assembly center of gravity. The RATO assembly also includes one or more motor tubes, depending on the intended application, made from readily available material, each tube designed to contain a rocket motor, casing, and related hardware. Additionally, one or more recovery tubes are coupled to the RATO bracket and rocket tubes. Each recovery tube contains a parachute, thermal protective material, ejection charge, and electronics bay with timer for the ejection charge. Finally, the RATO assembly includes one or more rocket motors, depending on the intended application.
POTENTIAL AREAS OF APPLICATION
- RATO systems
- Unmanned aircraft applications
MAIN ADVANTAGES
- No competition identified
STAGE OF DEVELOPMENT