Tanker Remote Vision System (TRVS)
The Tanker Remote Vision System (TRVS) supports the in-flight refuelling operator with adequate view on the refuelling scene below the tanker aircraft and information concerning the tanker process during air-to-air refuelling operations under bad visual conditions. TVRS was designed by TNO-FEL for the KDC-10 tanker aircraft of the Royal Netherlands Air Force (RNLAF) in 2006. KLM engineering & maintenance was responsible for designing and installation in the aircraft. TNO and its subcontractors were responsible for the architecture, hardware and software, production, testing and certification.
TRVS is based on a modular approach and consists of a surveillance vision system to obtain optimal situational awareness around the aircraft and a stereo vision system for crystal clear stereoscopic operator viewing along the refuelling boom.
The Royal Netherlands Air Force (RNLAF) employs two McDonnell Douglas DC-10 aircraft that were converted to serve as tanker and transporter in a mixed role. These aircraft are therefore designated as KDC-10 (‘K’ is the type designation for a tanker aircraft). The RNLAF KDC-10s resemble their American counterparts, however, they differ in fuel loading capacity and set-up of their in-flight refuelling system. In the RNLAF configuration, the boom operator station is located directly behind the cockpit. The boom is telecontrolled by using joysticks. The required visual feedback information is displayed on the operator console. The boom is controlled through a separate Boom Control Unit (BCU) which is part of the operator console. The BCU is not a part of TRVS. The TRVS interfaces with the BCU and receives information concerning the boom’s position and status. This information is presented in a graphic overlay on top of the refuelling image, together with the annunciators.
Visual information is generated by means of two video systems, a surveillance vision system, and a stereoscopic vision system. Together, these systems form the Tanker Remote Vision System (TRVS).
The surveillance vision system is based on three cameras covering more than 180 degrees horizontal field-of-view, between both the KDC-10’s wingtips in the aft direction. The images are displayed in a panoramic view on three monitors in the operator console. The stereoscopic vision system is based on dual-channel images from two cameras aimed at the refuelling boom tip. Stereoscopic images are obtained by using a shutter system. The operator wears passive polarised glasses that separate the images yielding a vivid stereoscopic image. The stereoscopic vision system also comprises synthetic symbology in depth. The vision system is suitable for day and night vision (near infra-red). TRVS has been proven as a high-performance vision system that has demonstrated its potentials during several air-to-air refuelling test flights.
The architecture of the TRVS is based on a modular approach. Five different modules are identified:
- Camera Module: the camera module is a mechanical construction including camera units. The Camera Module is placed in a camera bay under the tail of the aircraft to protect the cameras from severe environmental influence and dust during take-off and landing. The camera bay does not need pressurised air.
- Interface Module: The interface module contains the graphics processor units and an I/O processor unit. The graphics processor unit performs the image processing. The I/O processor unit takes care of interfacing with the boom control unit (BCU) and the operator control panels, and for generating caution and warning signals.
- Video Module: the video module consists of units for video switching, video recording and video playback.
- Monitor Module: the monitor module includes the video monitors for the surveillance vision system and the stereo vision system. The stereo monitors are equipped with a shutter system.
- Operator Control Module: the operator control for the TRVS vision system is performed by using the controls of the operator station.
- TRVS provides full operator viewing into direct sunlight, even in glare and blooming conditions. A superb picture for day, dusk and night operations exists.
- The surveillance system shows a high quality, more than 180 degrees panoramic field of view. High resolution and contrast sensitivity offer an extreme object detection range.
- The TRVS operator station offers a full-colour dynamic graphics overlay showing safety envelope brackets, boom position indicators, warning and caution indicators and fuel flow indication.
- The visual acuity of the video system approaches that of the unaided human eye.
- The stereoscopic system results in a depth acuity performance a factor three better than with the unaided human eye.
- The recording subsystem provides timestamped video for training and legal purposes.
- The use of high-performance monochrome cameras allows very high dynamic range and excellent contrast sensitivity.
- High system reliability and built-in diagnostics (user-initiated and continuous diagnostics) guarantee easy maintenance and repair.
- The use of polarised stereo imagery in combination with lightweight, easy-to-wear, polarised glasses for the operators guarantees a superb stereoscopic performance without the physical load that occurs in case a helmet mounted display is used.
- The modular system concept based on Line Replaceable Units uses fibre-optic imagery transmission in combination with complete digital image processing. This concept together with the extensive built-in test and diagnostic facilities offers a robust low-level maintenance solution for in-flight refuelling operations.
- TRVS is an effective and modest-cost solution to operate an air refuelling boom.
- TRVS can also be used for other applications such as improving the situational awareness aside the A/C (e.g., through video images of the Wing Aerial Refuelling Pods).
- Although initially designed for the KDC-10, TVRS can be used in any type of tanker aircraft.
- Field-of-view surveillance system: horizontal at least 180 degrees, vertical 62.0 degrees
- Field of view stereoscopic system: horizontal 35.5 degrees, vertical 27.0 degrees
- Certification based on DO-178B, DO-160D, DO-254
- Electrical power consumption: approx. 2 kW
- Total installed weight: approx. 280 kg