Tuesday, May 1, 2007
Look Ahead Avionics: Pursuing Intuition
With greater integration and computing capabilities, avionics systems will aim to give flight crews a quick and complete grasp of what their aircraft is doing and where it is in the sky.
IT’S FAR FROM CERTAIN WHAT COURSE THE DEVELopment of vertical lift will take over the next 40 years, and whether the results will be evolutionary or revolutionary. What is certain is that avionics will be at the heart of those developments.
Many people disparage what seems the popular trend of attempting to solve every problem by throwing a black box at it. But the key challenges facing the vertical-lift industry are of a type custom-made to be handled by the "black box" — that generic term for an electronics-based solution whose inner workings are too intricate for all but the specialist to comprehend.
Improving the speed, range, and payload efficiency of rotorcraft require flight control and power systems that can sense and adjust themselves continually to changing aero- and thermodynamic conditions.
Achieving greater levels of rotorcraft safety demand systems that can constantly apprise a pilot of his aircraft’s position, condition, and attitude in the air and in relation to hazards such as obstacles, terrain, weather, and other aircraft.
Fulfilling the mission requirements of the future with a shrinking base of pilots and mechanics call for greater use of automated systems to manage routine tasks. In the air, that may mean unmanned systems flying powerline patrols and other missions in which a pilot isn’t required in the cockpit. On the ground, computers will be needed to track the health of aircraft systems, anticipate their failure, and have the procedures and parts ready to replace them when they go.
Prevailing against dispersed, unconventional enemies armed with a diversity of threats argues for the ability to reconnoiter large stretches of the battlespace with a multitude of unmanned systems that can communicate with each other and the manned platforms and keep soldiers out of harm’s way.
All of these aspects of the future demand the ability to program tasks, process data, assess and respond to its output, and communicate responses. That will require managing the collection, analysis, and prioritization of information to free the person in the loop to focus on the most important tasks. That is to say, these situations require avionics, and avionics of a variety that are more capable and intuitive than today’s systems.
I can See Clearly
The trend toward such systems is already under way. Chelton Flight Systems’ Electronic Flight Instrument System (EFIS) is one example, with its ability to synthesize multiple pieces of information into a display that improves a pilot’s awareness of his situation in the air and his ability to navigate away from hazards. Central to its capability is its synthetic-vision primary flight display, its helicopter terrain awareness and warning system, and its Highway-In-The-Sky navigation system.
Chelton is enhancing its capability with the Heli-SAS autopilot it is developing for the Bell Helicopter 206 and 407. It is developing supplemental type certificates for the system’s installation with Bell subsidiary Edwards & Associates; they are aiming for certification this year.
Honeywell now also is developing integrated primary flight display technology for helicopters, including synthetic vision.
Thales is in position to tackle tomorrow’s problems, with Sikorsky Aircraft’s selection of its TopDeck integrated avionics system, for the Sikorsky S-76D. Thales also is providing the system, which features four 6X8-in flat-panel liquid-crystal displays for the AgustaWestland A109LUH light utility helicopter program. It has proposed TopDeck as a solution to return to the sky eight United Kingdom Royal Air Force Chinook HC3s ground seven years by avionics certification problems.
The glass cockpit for the S-76D is derived from the modular avionics developed by Thales for the Airbus A380 airliner. The A380’s 8X10-in EFIS panels were scaled down to fit a helicopter cockpit.
A big hurdle to meeting the operational challenges of tomorrow is developing an avionics system that can evolve with those challenges. That requires the use "open architecture" avionics designs, a concept that has been around for years that as often as not has been given lip service.
While the military typically leads technological developments in rotorcraft, it has been difficult for it to lead the drive toward true open-architecture systems, which establishes a common software frame to which competing avionics companies can mate their boxes. The main reason is that, for years, the military would contract for avionics systems, but it could not afford to pay the price of buying all of the rights to the systems’ software. As a result, if operators wanted to add systems to an aircraft, program managers typically had to go back to the software designer to do that. That drove up the cost, complexity, and time required to evolve an avionics suite.
For people who live and work in the age of "plug-and-play" personal computers, that’s difficult to understand.
Manufacturers on the civil side are pursuing "plug-and-play" capability. Bell Helicopter’s 429 GlobalRanger, is the flagship of that company’s effort to make it simple and easy for operators to customize the suite of avionics they choose for the aircraft. In an approach it calls BasiX, Bell is bringing in house the design of the "brain" of the aircraft, the digital acquisition unit, for the 429 and follow-on aircraft. Essentially the mission computer, this unit governs the performance and functions of the aircraft’s flight control system, engines and navigation and communications systems.
This move runs counter to 20 years of farming out "non-core" work, but reflects Bell’s recognition that the most critical skill in the avionics-integration process is familiarity with the aircraft.
The objective of BasiX designers is to provide as many interfaces as possible, so any commercial application with an ARINC 429 interface can easily be put into the aircraft.
The BasiX integrated avionics on the 429, dubbed BasiX-Pro, includes as standard elements two large-screen, multi-function flight displays ready for use with night-vision goggles. It also includes the dual digital, three-axis coupled autopilot with stability and control augmentation; state-of-the-art dual air data and attitude heading reference system; incorporation of all engine and system indications and crew-alerting systems into the glass-cockpit displays; electronic engine control; an electronic standby instrument system; dual navigation, communications and GPS systems with color mapping displays; an elementary surveillance-compliant Mode S transponder; a traffic information system, and a stereo-provisioned audio and intercom panel with marker beacon.
The 429 also is to have the on-screen programming in the cockpit to permit operators to load configurations for a variety of instruments and avionics units, from radar altimeters to terrain awareness and warning systems and forward looking infrared units.
The U.S. Army has taken up the open-architecture banner. Its Manned Unmanned Common Architecture Program (MCAP) aims to enable teams of manned and unmanned aircraft to use low cost modular, commercial-off-the-shelf electronics and open-systems interface standards for advanced mission processing.
Under a contract from the Army’s Aviation Applied Technology Directorate, Rockwell Collins and Boeing are working to develop a common mission-processing architecture for manned and unmanned aircraft. Phase 2 of the project, led by Boeing, is to create an open-system, scalable mission avionics architecture for the AH-64D Apache. Phase 3, headed by Collins in collaboration with AAI and Whitney & Bradley & Brown, will develop a mission avionics architecture for an Army unmanned air vehicle (UAV).
Army and program officials hope MCAP will lead the service into the future and offer increased interoperability between manned and unmanned aviation systems and reduced life-cycle costs through use of open industry standards and development of a common mission processing architecture.
Rockwell Collins is performing systems engineering activities to define a common computing and network architecture with application to UAVs, including the Shadow 200, the A-160 Hummingbird, and Fire Scout.
The Aviation Applied Technology Directorate will take advantage of that capability quickly. It already has teamed two unmanned helicopters in a successful demonstration of its Unmanned Autonomous Collaborative Operations (UACO) program.
"It’s the UAV-as-wingman concept," said Ray Wall, director of the Systems Integration Div. at the Army directorate. He explained that the goal is to not have the pilot plan out the UAVs mission, but to give it what he calls higher level guidance. In a simplified explanation, that is to communicate to the UAV that "I am going to do this mission. I want you to go do that," that being to examine a tree line or a section of an urban area.
"You’re not giving it waypoint guidance. You’re not flying the UAV."
Under contract to the directorate, robotics developer PercepTek, Inc. and subcontractor Carnegie Mellon University flew two Yamaha RMAX unmanned helicopters through a number of mission objectives at the same time. The UAVs searched for specific vehicles and troops and tracked moving vehicles in complex terrain.
The UACO program aims to give a single operator control of multiple unmanned air and ground vehicles to support soldiers in urban areas. The Army directorate awarded UACO contracts in 2004 to develop advanced autonomy and collaboration algorithms for UAVs. To wrap up that part of the contract, the UAVs planned, assigned, and performed tasks.
During that, they mapped terrain and avoided obstacles and relayed communications. They reallocated tasks in response to real-time events including simulated equipment failures and occluded lines of sight.
In a demonstration of collaboration among air and ground units in engaging targets, Wall said, a ground operator controlled three UAVs and two unmanned ground units "and it wasn’t taking up his full-time effort,"
UACO aims to develop and demonstrate cooperative behaviors among multiple UAVs. The combination of this interface and advances in perception will enable a single operator to run multiple UAVs in a coordinated manner, thus improving mission effectiveness.
See Them First
As Wall envisions it, "a combat force going in will have UAVs which are sent forward as observers, spotters, or to communicate with ground forces. This would allow the pilots of the manned aircraft to see the forces they are engaging before they get there."
Advanced navigation capabilities will help improve the efficiency and safety of rotorcraft operations in the future. The advent of automatic dependent surveillance-broadcast unleashes air traffic control from ground-based radar while at the same time providing means of communicating real-time weather and hazard advisories to crews in the air.
Multi-lateration is the development coming down the road for air traffic control technology. Advocates say it will eventually replace most transponder tracking ATC radars, and do so cheaper. It is being adopted rapidly by airports and airspace agencies around the world.
Multi-lateration is based on the principle of triangulation. But this system doesn’t triangulate by taking bearings. It uses listening post around an airport to monitor local traffic; in its wide-area configuration, it can cover much larger areas of airspace. They listen for transponder returns. It is designed to monitor Mode-A/C, Mode-S, ADS-B and military IFF transponders.
Each station sends the data from the received signals every second to a central data processor that does triangulation and time-of-arrival computations to derive the precise positions of all aircraft, which are then sent to ATC.