RS-100 Virtual Reality Refueling Simulator
Typical Computer-generated Pilotís Scene
The RS-100 is a virtual reality air-to-air refueling simulator technology demonstrator in which the computer generated scenery appears on a helmet-mounted display (HMD). A typical RS-100 image is shown above. The interior of the pilotís ownship, including the instrument panel gages and indicators can all appear in the display along with out-the-window imagery.
The RS-100 simulator incorporates a number of innovative features aimed at driving down the cost of air-to-air refueling simulators. Key features include:
The stereo helmet-mounted display utilizes two channels of computer graphics to support a total field-of-regard of more than 180 degrees in both the horizontal and vertical directions as the pilot moves his head from right to left and from up to down. Conventional air-to-air refueling simulators using projection displays typically require three graphics channels and three projectors and screens for the scenery, and a detailed cockpit mockup Ė all very expensive. Using projection screens or monitors also takes up considerable floor space. The use of virtual reality limits the required floor space for the RS-100 system to about 20 square feet. The system includes an optical tracker for head position which, unlike magnetic trackers, works without interference from other nearby simulators or equipment.
How does the RS-100 work?
Before the simulation exercise begins, the computer keyboard and trackball are used to select tanker altitude, visibility range, and turbulence conditions. Once the desired conditions are selected, the simulation exercise can begin.
During the simulation, the optical tracker monitors the pilotís head position. To track the pilotís head position, the optical tracker electronics causes the four infrared light emitting diodes (LEDís) located on the helmet-mounted display to illuminate in sequence. Two sensors located in the tracker sensor unit then triangulate the position of each LED and compute the position and attitude of the pilotís head. The computer also monitors the position of all pilot flight controls via the data acquisition card. Using this data and simplified flight model software the computer system generates a 3-D image corresponding to the current head, ownship, and tanker position. The image is displayed on both the pilotís helmet-mounted display and the local monitor. The local monitor is used for simulation setup and also allows other people to watch the progress of the simulation.
The CGSD-developed rugged housing encloses a commercially available Sony HMD. A picture of the ruggedized HMD is shown below. When used with the RS-100, an optical tracker emitter assembly (not shown) is mounted on top of the horseshoe-shaped piece that surrounds the HMD optical unit. Small speakers positioned near each ear provide stereo audio cues.
Ruggedized Helmet-mounted Display
The tanker aircraft is programmed to fly in a "racetrack" pattern at the altitude selected at the beginning of the training exercise. The highly detailed tanker model (shown below) includes typical U.S. Navy markings. Depending on the selected turbulence conditions, the refueling basket and hose will move erratically increasing the difficulty of refueling.
KA-6A Tanker Model
A highly detailed 3-D model of the ownship cockpit interior is provided. The head-tracked helmet-mounted display in combination with the 3-D cockpit model allows the pilot to see around such things as the window struts. Instruments and instrument panels are accurately sized and positioned in 3-D space to provide realistic queues as the pilot moves his head. While most instruments are static and do not move as the simulation progresses, several cockpit instruments are updated in real time to allow the pilot to locate and rendezvous with the tanker. These include an attitude ball, an airspeed indicator, and a radar indicator. The radar indicator presents range and azimuth to the tanker. Once rendezvous is accomplished, the pilot can maintain relative position with the tanker using out-the-window imagery for flight queues. The pilot controls the flight of the ownship with a joystick, throttle, and rudder pedals (optional).
A database showing terrain and a shoreline is provided. At normal refueling altitudes it provides horizon reference and motion queues.
The RS-100 technology demonstrator is pictured below along with a system block diagram. The hardware, consisting of a single 19-inch electronics cabinet and a pilot station, includes rugged arcade quality flight controls and an industrial rack-mounted computer. Note; the HMD shown here is not the ruggedized Sony HMD discussed elsewhere in this description.
Navy visitor tries simulator at I/ITSEC 1999
RS-100 Hardware Block Diagram
For further information please see our Frequently Asked Questions page and the Product Specification.