Feb 24 2012

How Technology Has Changed the World of Simulators Posted 12 years 274 days ago ago by Admin

Story by Casey Duke

Photos by Casey Duke & Lyn Burks

 

Introduction

Advancements in technology and material make modern simulators more realistic and effective than ever. Regulating this new generation of synthetic training devices has also taken the first steps in keeping up with the changes. This article details some of the technology advancements in simulation and looks at the future of simulators as well.

 

What is a Simulator?

In its basic form, a simulator is a device that lets you experience or practice a skill or task without the cost or risk associated with doing that task in whatever is being replicated. Today’s gaming stations (X-BOX, PlayStation) are examples of simple simulators. They meet the basic criteria; a user to computer interface (hand controller); a processor for interpreting inputs; a visual image generator, and a processor for integrating it all together into a synthetic environment where the user is actively involved in the displayed activity.  We’ll limit the discussion to full flight simulators (FFS).

 

Using the game station example above, modern flight simulators are highly sophisticated models of the same principal. There is the user to computer interface, in our case a cockpit with transducers, potentiometers, switches and an assortment of other expensive components convert pilot outputs into coded input for the processors. Those processors interpret the pilot’s movements and, working through a motion system and visual system processors,  create a virtual flight environment rivaling that of reality. One of the greatest benefits of the latest generation of simulators is the ability to offer zero aircraft time training, including full emergency and abnormal procedures drills in a device that never leaves the ground. 

 

The Cockpit

Simulator manufacturers can use repurposed cockpits or in some instances, fabricate fiberglass or plastic cockpits. Over the years, many original equipment manufacturers (OEM) have established alliances with flight training providers and simulator manufacturers. CAE, FlightSafety, Boeing and Rockwell are training providers that manufacture their own simulators.

 

Simulators can be built without the cooperation of the OEM. However, this often turns into a drawn out reverse engineering drill adding time and expense.  Equipment has to be bought, and then it has to be integrated into the other simulator systems.  Another aspect that can’t be understated is the availability of “data”.  If it isn’t available through the OEM, then it has to be collected from a real aircraft at considerable expense. This may lead to an arrangement with a customer to provide a line aircraft for the collection of flight data and this is very expensive. 

 

The Processor

Another improvement involves the processors. Just as home computer chips have gotten faster and smaller over the past 20 years, so have the chips used in simulation.  At one time, a high end simulator required a large room to handle the computer cabinets and environmental control units.  All that processing power was dependent on the availability of electrical power that could only be provided by a nuclear reactor and  staff engineers festooned with pocket protectors, lab coats and thick framed glasses.  You may remember those days.

 

Because the capability to store and retrieve large amounts of data was not available, the processors were actually printed circuit cards with as much on board memory as could be soldered to them. Dozens of those cards were inside the cabinets. The processor had instantaneous access to the memory eliminating latency (read-write delay),  which allowed for rapid response to pilot inputs.  However, the undesirable byproduct of all those circuit cards was heat. Unfortunately, heat remains the enemy of computer circuits. To mitigate heat, cooling and dehumidifying the air ensured the processors were able to operate at peak capability and speed.  With newer and faster processors, the need for board mounted processing power combined with room filling cabinets is a thing of the past.  Modern simulators can be controlled by a single commercial off the shelf (COTS) desktop processor and a few terabytes of hard disk storage.  Virtual environments can be added by simply swapping a hard drive with the new database.  We no longer require the large computer rooms, or additional nuclear power plants. We also no longer need teams of computer software engineers.  For the training provider, these savings ultimately boil down to a better income to expense ratio. 

 

Advanced modern processors have also improved the virtual world the pilot sees out the window.  Helicopter pilots need accurate, high-resolution three dimensional models to train for missions they are expected to accomplish. Long gone are the days of huge terrain boards populated with miniature trees, cars, airports, and the occasional insect fixed to the board by a technician with a skewed sense of humor. Engineers are now able to create life like models and environments that were not possible  even 10 years ago.  New image generators (IG) are capable of producing from 75,000 to over 100,000 polygons per channel (that is a lot) and over 2 million pixels (also a lot). CAE’s Tropos™6400 and FlightSafety’s VITAL X are two examples of next generation IG’s for their respective commercial simulators. Helicopter visual models routinely use 1 foot resolution imagery data, but can also use resolutions down to ¼ inch for texture rich scenes (blowing grass, tree leaves, snow etc.).  1 meter scaled imagery is sufficient to meet most of the detail requirements for in-flight situations.  This level of detail allows pilots to train “virtually” at any airport in the world without actually going there.

 

Models of LAX or JFK, for example, can be used to provide specialty training for operators in those regions. Off-shore oil platforms and ships are now being created with exact detail further enhancing the experience of the pilots who will be flying to those rigs soon after leaving the safety and security of the simulator. Until very recently, the texture rich detail found in nature hasn’t been adequately recreated in the current visual models. The basic visual models are very good in most respects, but the RW pilot is hampered by the limited resolution and inadequate luminance levels in the “out the window” display.  Instructors often use valuable time during the first simulator session to train the clients how to handle the simulator specific issues and limitations.  In other words, instructors must teach the client how to fly “the box” before teaching  them how to fly the aircraft it represents.  This creates an unnaturally long training process that can have negative consequences in the form of lack of confidence for the pilot and concerns of expense for the operator.  

 

The Projector

 

Having the capability to produce super rich detail is only half of the battle. The next generation of projector is finding its way into the simulator, further enhancing what the pilot sees. Cathode Ray Tube (CRT) projectors worked well, but had poor luminance capabilities and required continuous maintenance. New Liquid Crystal on Silicon (LCoS) projectors are changing the way pilots see their virtual world.  These projectors are doing for simulation displays what High Definition and Blu-Ray have done to television. Companies such as Barco, Christie, JVC and others are now building high definition projectors for simulation and other specialized purposes taking full advantage of the capabilities with the new IG’s. Until recently, technical and regulatory issues limited their use to the fixed wing devices.  They are now slowly making their way into rotary-wing simulators and improving the training experience for the pilot.

 

Another visual enhancement that is showing promise is direct projection displays. Direct projection systems have not replaced the collimated display systems currently in use, but it is hoped that methods to fully capitalize on the advantages of such systems will be developed and employed. However, only level B simulators and select Flight Training Devices (FTD) are exploiting the attributes of direct projection systems. Presently, level C and D simulators are required by appendix 1 to FAA Advisory Circular 120-63 to use the collimated display (or equivalent).  Collimated display systems remain the primary visual systems in nearly every commercial flight simulator because they provide very close to the same perspective for crewmembers regardless of viewing position within the simulator cockpit.

 

“She’s Got Legs”

Another dramatic advancement in synthetic flight devices is the introduction of the electric motion base.  Past simulators were supported by hydraulic powered legs providing necessary movement in each axis.  The hydraulic legs require gallons of fluid under constant pressure allowing rapid response when commanded by the processed pilot input. To keep the fluid under pressure, large hydraulic pumps are required to run almost continuously. These pumps require lots of energy to operate. While the hydraulic operated systems have remained reliable and effective, they are expensive. Increased awareness of the potential impact to the environment has also helped expedite the development of the electric based motion system, since even a small failure would not only be catastrophic to training, but could detrimentally impact an eco-system. The result would be increased governmental scrutiny, fines and even long term loss of revenue.

 

The development and implementation of electric motion control  has proven to be one the most significant improvements to occur in simulation in the past decade. Electric motion bases look very much like the hydraulic systems they replace, but there are no hydraulic lines, meaning no hydraulic pumps which remove the environmentally hazardous hydraulic fluid. Unlike hydraulic pressure which must remain constant even if the motion base is stable, such as it is in cruise flight, the electric base only uses energy to position the platform to a desired position. Once the platform has achieved the desired position, electric power is removed until the computer commands the base move in reaction to pilot input, turbulence or some other cue as dictated by the scenario being played out in the simulator. The electric motion system has revolutionized the full motion simulation for virtually every manufacturer.

 

A Peek Into the Future

Long gone are the devices that were best suited for developing cross check IFR skills. Through continuous development and improvement, the new generations of simulators are highly sophisticated full mission training devices.  Operators can prepare for any type of mission in any environment before ever attempting it live. Emergency and contingency training can be considered and mistakes can be identified and corrected. Situational awareness and crew resource management can be honed without the risk of injury or damage to anything but ego and pride. The latest materials, the fastest processors, and the cleanest (and greenest) simulators are now finding their way into training centers worldwide. If governmental oversight can keep up with the current pace of progress, the next decade should prove to be very exciting for training providers, operators and most importantly, pilots. The future outlook includes super thin curved plasma or LED screens that can be stacked to create a frameless,  contiguous, out the window display with high resolution graphics and high luminance qualities. Expect to see virtual reality helmets or glasses soon. They will eventually eliminate the requirement for bulky collimated display assemblies all together.