Instrumentation Monthly Test | Measurement | Control
Happy Landings Flight Simulations build and run technically sophisticated flight training simulators that have equal appeal for leisure users and budding pilots.
With six highly detailed simulator models covering a range of aircraft types including helicopters, jets and commercial airliners, they include motion controlled replicas of real cockpits and surround screen HD graphics for terrestrial features and international airports. To improve the performance and reliability of the roll and pitch axes for its Cessna C172 ‘Skyhawk’ simulator, Happy Landings have recently replaced gear mechanics and rotary potentiometers with SP1 and SM1 draw wire position sensors from Variohm EuroSensor.
As directly coupled measurement devices, the draw-wire (or cable extension transducer) solution reduces the potential for lost motion in the control system and improves the control sensitivity – and ultimately enhances the flying simulation experience. The SP1 series draw wire sensor provides a robust and compact position measurement solution for up to 1.27 metres travel whilst the miniature SM1 has the ability for even more compact installation for travel lengths to 0.63 metres. For this application both sensors are configured for voltage divider output from integral potentiometers with a measurement resolution which is essentially infinite and repeatability in the region of 0.5% full scale. A sturdy nylon-coated stainless steel cable connects the moving load to the potentiometric sensor through a spring loaded winch mechanism. Typical working life is more than 2.5 million cycles. Featuring durable polycarbonate housings with multiple mounting points they are easily installed and do not require perfect alignment.
Draw wire sensors may also be specified with IP67 protective housings for use in harsh outdoor environments where long travel, high accuracy linear position measurement is required. A wide range is available from Variohm EuroSensor with optional mechanical fixings, selectable voltage and current outputs as well as CANopen, SSI and other fieldbus interfaces if required. Draw wire sensors are well proven for positioning and linear measurement tasks in demanding applications such as high performance car throttle controls, elevating bridge and crane controls, heavy industrial equipment, agricultural and construction machinery.
