Aerospace & Defence
usually they are fitted by bonding or encapsulation to the host mechanical structures such as the aileron, wing spar, gearbox, seat etc. They will often be completely embedded in resin for example. The printed feedback devices do not need a precision alignment of the moving and stationary parts of the sensors, so further mechanical elements such as guides, bushes, bearings and seals can also be eradicated, producing further weight savings. The advantages of such printed technologies does not just end with weight reduction at the actuator
itself. Their weight advantage is increased still further due to the eradication of cabling between actuator and centralised control units - typically a flight control unit (FCU) or actuator control unit (ACU). Traditionally, these centralised units receive signals from the servo feedback device and motor encoder and, in turn, transmit the required power to the motor. Such signal and power lines might typically require 14 individual wires per actuator. Compare this to the printed approach, where the intelligence is distributed to each of the actuators. The software for actuation is embedded into the printed sensor’s control circuit. There is no need to transmit power and signals for
computation to the centralised unit since the necessary computation is carried out at the actuator itself. Only command signals and power are transmitted from the ACU or FCU to the actuator. Since the command signals can be provided over the power lines, only a 2-wire bus is required. The use of printed electronics technology is already
well underway in the military sector - they are flying today on UAVs in their electrical actuation and control systems. In time, it will be adopted by the civil sector because advantages are so significant over traditional techniques. The driving force will be increased fuel efficiency as a result of weight reduction. ●
Fig. 2. Printed plastic sensor technologies from UK company called Zettlex.
ABB BAE Systems Blackfast Chemicals Bossard CRC Press CarlStahl Clippard ContiTech Dejond Digital Mechanics GBK Gates Gesipa
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10 39 17 6
26 48 28 34 28
58
www.engineerlive.com
Steven Bowns is a consultant at Technology Futures, Cambridge, UK.
www.technology-futures.co.uk
Gutekunst Federn IRISS Inpro/Seal LB Blömker Lohmann Micro-Epsilon Nord-Lock Ondrives Phytron PiezoMotor S.S. White Technologies SPS IPC Drives Trelleborg Engineered Fabrics
28 14 13 37 31 19 33
IBC 48
IFC 21 26 22
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