UAV’s require several systems to keep them in the air and allow them to complete their mission. I have been working in the UAV business over 10 years mainly supporting propulsion systems but in the last 5 years I have expanded my business to include other systems. My focus for UAV Propulsion Tech, is to find the best UAV solution providers outside of the US and offer their solutions into the US UAV market. I thought I would summarize these solutions in this months blog.
The graphic below shows the systems that will be detailed further below.
A: Propulsion- This is what keeps the UAV in the air but also provides electrical power to the air vehicle and payload via a generator. It also can include an engine mount which is critical to minimize vibration transmission to the payload which can cause camera issues. It also typically has an engine management system that interfaces with the flight computer to monitor engine health (like cylinder head temp, exhaust gas temp, throttle position, manifold air pressure, and can also calculate fuel consumption). The propeller is tested with the engine (and sometimes supplied) but is usually specified by the UAV manufacturer’s aerospace engineers. The propeller can be direct driven from the engine or utilize a propeller speed reduction system (either belt or gear) to allow the UAV to utilize a larger propeller spinning at a lower speed. This decreases noise and increases thrust.
UAV Propulsion Tech provides propulsion solutions from Orbital (Australia) and Hirth (Germany). Orbital’s expertise is in custom direct injected 2-stroke engines that enable operation on heavy fuel’s such as Jet A, JP5, JP8. The DI system provides significant fuel consumption reduction benefits at cruise because the engine can run leaner than a typical port injected or carbureted engine. They can also apply their direct injection system to existing piston or rotary engines to improve the combustion process and enable operation on heavy fuel. Examples of their UAV customers (in the public domain) include the Aerosonde MK4.7 engine (now produced by Lycoming) and the new ScanEagle N20 engine (recently detailed in Unmanned Systems Magazine – #8).
Hirth’s expertise is in COTS and custom 2-stroke aircraft engines and they currently produce engines from 8hp to 100hp. They have been in business for almost 100 years and have produced over 1 million engines. Their 2-strokes are used in ultralights, powered parachutes, gyrocopters, gliders, hovercraft, generators, water pumps, go-karts and UAV’s. Their technologies include advanced engine management systems for both gasoline and heavy fuel, integrated starter/generators and relationships with some of the most reputable 2-stroke components suppliers in the world. Their UAV customers (in the public domain) include: Saab Skeldar, Indra Pelicano, EMT Luna, Dronetech AV-1 Albatross, Northrop Bat, Denel Seeker 200, Ruag Ranger, and IDS Hero-150.
B: Gimbals- The primary UAV payload is typically a gyro-stabilized electro-optical (EO) and infrared (IR) camera gimbal. The payload can also have a laser range finder or pointer. These gimbal systems also have optional video tracking, geo-location and geo-positioning. UAV Propulsion Tech provides gimbal solutions from DST Control (Sweden). These systems are flying on several UAV’s today and their OTUS-U135 is one of the smallest gimbals on the market with the best value for the advanced capabilities it provides. The OTUS-U250 is a 10″ gimbal and is the largest in the DST Control family and is very cost competitive compared to other solutions of similar size.
C: Fuel Modules-Another critical system in a UAV is the fuel delivery module. This would typically include a fuel tank, fuel pump, and fuel level sensor. The operation of the UAV can impact delivery of fuel to the engine which can cause fuel starvation and engine stall. Critical events can include launch, altitude pressure changes, and flight maneuvers (pitch/yaw). The fuel delivery module also has to provide a means to minimize slosh effects and provide filtered fuel to the engine. UAV Propulsion Tech provides fuel module solutions from Orbital. The picture below shows the new ScanEagle N20 propulsion system which includes the engine as well as the fuel delivery module. Orbital can develop custom turnkey fuel delivery systems for a specific UAV application.
Hirth does not provide fuel delivery modules but does provide in-line fuel pumps and fuel pressure regulators for all UAV engines. Shown below is a fuel delivery module concept from UAV Propulsion Tech that shows a COTS configuration that can be customized for specific applications. This is shown just to illustrate a typical tank system and is not available for sale. Fuel delivery modules can however be provided by Orbital.
D: Autopilots-The autopilot is a critical system of a UAV and is responsible for controlling the flight of the UAV. It ties into several UAV systems to enable autonomous or remote piloted flight. The autopilot links to a ground control station (GCS) via a radio modem and the GCS is used to develop waypoints for the flight plan and monitor operation. UAV Propulsion Tech provides autopilot solutions from MicroPilot (Canada). MicroPilot has been providing professional autopilots for the UAV market for over 20 years and has systems flying all over the world. Their autopilot solutions include board mount (weighs only 28g), enclosed (includes redundant long range communication data link) or triple redundant (3 autopilots for ultimate reliability). These solutions have been developed for fixed wing, multi-copter, and helicopter applications. MicroPilot’s autopilots are not open source but they do offer XTender which is a software developers kit to enable customization. This allows the UAV customer a way to differentiate their UAV from their competitors. MicroPilot’s True Hardware-in-Loop simulator offers UAV integrators and researchers the highest fidelity autopilot simulation available on the market today.
E: Parachutes – Parachutes can be used in a UAV as a means of recovery (instead of a net or runway) or as a means of rescue in case of a system failure. Most are used for rescue situations to save the air vehicle and payload assets. The challenge is always trying to find space for a parachute and deal with the added weight. UAV Propulsion Tech provides parachute solutions from Skygraphics (Germany). Their ProtectUAV parachutes provide a lightweight/compact solution over other products on the market. They are currently being utilized by several UAV companies and ProtectUAV also recently launched a multi-copter solution. ProtectUAV’s solutions cover fixed wing applications up to 200kg MTOW and multi-copter applications up to 28kg MTOW.
F: Servos-Another critical component for UAV’s are servos. Servos are used to move control surfaces (like rudder, ailerons, flaps, etc.), control the engine throttle and sometimes used to trigger certain options (like a compartment door for a parachute). UAV Propulsion Tech provides servo solutions from Volz (Germany). Volz has been designing/producing high end servos since 1983 and are flying on several UAV’s including Aerosonde MK4.7, Northrop Bat, Schiebel Camcopter, Airbus target drones, Lockheed Martin Fury, Aeronautics Orbiter and several others. They provide a complete range of servos from DA15 (15mm) to DA30 (30mm) and are now offering redundant and OPV (optionally piloted vehicle) variants of their larger DA26 and DA30 servos.
They also have throttle servos that can be mounted directly to the engine throttle and can withstand the vibration because of their brushless motor and contactless sensor design.
Key UAV News for the Week:
- NCTC Announces Collaborative Agreement With Northrop Grumman
- General Atomics Gets $9.6M Precision Tracking Award
- British Army Watchkeeper UAV downed by computer glitch
- Iran Unveils Long-Range Bavar-373 Air Defense System
Industry Events for August:
- UAS Summit and Expo – August 22-24, Grand Forks, ND http://www.theuassummit.com.
- AUVSI Pathfinder – August 30-September 1, Huntsville, AL www.auvsipathfinder.com
- UAS West Symposium – August 30-31, San Diego, CA. www.uaswest.com/
Quote for the week:
“The human spirit is like an elastic band. The more you stretch, the greater your capacity.” – Bidemi Mark-Mordi