1、SAE Technical Standards Board Rules provide that: “This report is published by SAE to advance the state of technical and engineering sciences. The use of this report is entirelyvoluntary, and its applicability and suitability for any particular use, including any patent infringement arising therefro
2、m, is the sole responsibility of the user.”SAE reviews each technical report at least every five years at which time it may be reaffirmed, revised, or cancelled. SAE invites your written comments and suggestions.Copyright 2002 Society of Automotive Engineers, Inc.All rights reserved. No part of this
3、 publication may be reproduced, stored in a retrieval system or transmitted, in any form or by any means, electronic, mechanical, photocopying, recording, or otherwise, without the prior written permission of SAE.TO PLACE A DOCUMENT ORDER: Tel: 877-606-7323 (inside USA and Canada)Tel: 724-776-4970 (
4、outside USA)Fax: 724-776-0790Email: custsvcsae.orgSAE WEB ADDRESS: http:/www.sae.orgAEROSPACE STANDARDAS5392Issued 2002-12Health and Usage Monitoring System,Rotational System Indexing Sensor SpecificationTABLE OF CONTENTS1. SCOPE .21.1 Classification21.2 Specification Terminology22. REFERENCES .23.
5、DEFINITIONS.34. REQUIREMENTS AND RECOMMENDATIONS 34.1 Self-Powered Sensor Interface34.2 Externally Powered Sensor Interface 65. NOTES .95.1 Comments to Sensor Subsystem Designer.95.2 Principles of Operation - Different Sensor Technologies .10FIGURE 1 Self-Powered Sensor Subsystem-to-Electronics Inte
6、rface 3FIGURE 2 Representative Passive Magnetic Sensor Output Voltage.4FIGURE 3 Typical Passive Magnetic Sensor Phase Variation 5FIGURE 4 Noise Spectrum6FIGURE 5 Externally Powered Sensor Subsystem-to-Electronics Interface .7FIGURE 6 Typical Phase Variation for the Digital Sensor .8SAE AS5392 - 2 -1
7、. SCOPE:This SAE Aerospace Standard (AS) specifies requirements for the interface between a rotational system indexing sensor and its interface electronics. These sensors generate one or more electrical pulses for each revolution of the shaft being monitored. These pulses can be used to determine th
8、e actual shaft rotational speed and/or position for use in a Health and Usage Monitoring System (HUMS). Indexing sensors are used in the following HUMS areas on the aircraft: (a) rotor track and balance, (b) engine vibration monitoring and diagnostics, (c) drive train vibration monitoring and diagno
9、stics. The goal of this standardization effort is to be able to take any compliant indexing sensor and connect it to any compliant interface electronics.These SAE HUMS Interface Specifications include the minimal interface and performance requirements for interoperability with the Rotorcraft Industr
10、y Technology Association (RITA) compliant HUMS. Compliance with these Interface Specifications can be referenced in more comprehensive procurement and device specifications.1.1 Classifications:Two general classifications of sensors are considered in this specification, those that are self-powered su
11、ch as passive magnetic sensors and those that require an external source of power to operate such as optical sensors. This specification addresses the self-powered and externally powered sensors separately because of the significant differences in their interface requirements. While these two sensor
12、s types have very different outputs and are considered separately in this specification, a common electronic interface could be designed to accommodate both sensor types.1.2 Specification Terminology:The terms “shall” and “should” within this specification observe the following rules:a. The word “sh
13、all” expresses a mandatory requirement of the Specification.b. The word “should” expresses a recommendation or advice on implementing the specification or actions expected of users of the system.2. REFERENCES:There are no referenced publications specified herein.SAE AS5392 - 3 -3. DEFINITIONS:SENSIT
14、IVITY - The ratio of change in sensor output as a result of a unit change in measurand.SENSOR - A measurement device that transforms one form of energy into another. Also referred to as transducer or pickup.TRANSDUCER - See Sensor.4. REQUIREMENTS AND RECOMMENDATIONS:This specification is divided int
15、o two major sections titled “Self-Powered Sensor Interface“ and “Externally Powered Sensor Interface.“ The major sections specify the interface requirements for the two sensor types. Each of these major sections is further divided into two subsections titled “Sensor Interface Requirements“ and “Inte
16、rface Electronics Interface Requirements.“ The major sections were divided into, the above mentioned, subsections to aid the supplier of the sensor or interface electronics in identifying the applicable requirements.4.1 Self-Powered Sensor Interface:Self-powered sensors are sensors that generate an
17、electrical output signal without the use of batteries or an external power source. The most common self-powered sensor is the passive magnetic sensor. A description of passive magnetic sensors is provided in 5.2.1. The self-powered sensor typically produces a sinusoidal like voltage output. FIGURE 1
18、 - Self-Powered Sensor Subsystem-to-Electronics Interface4.1.1 The following subparagraphs provide interface requirements for the sensor side of the sensor-to-electronics interface.SAE AS5392 - 4 -4.1.1.1 Sensor Output Voltage: An idealized trace of the self-powered sensors output voltage (Vsignal)
19、is shown in Figure 2. The amplitude of the output voltage signal is a function of the relative target/sensor speed, the spacing between the target and sensor, the sensitivity of the sensor, the size and material used for the target, and the electrical load. This document does not specify the number
20、of targets the sensor shall observe per revolution. The interface specification only requires that the zero crossing point shall be well defined as shown in Figure 2.FIGURE 2 - Representative Passive Magnetic Sensor Output Voltage4.1.1.1.1 Maximum Sensor Output Voltage: The maximum sensor output vol
21、tage (Vsignal) shall not exceed 60 V peak to peak (P-P) at a 15 k load.4.1.1.1.2 Minimum Usable Sensor Output Voltage: The minimum usable sensor output voltage (Vsignal) shall be 1 V peak to peak (P-P) at a 15 k load.4.1.1.2 Sensor Output Impedance:4.1.1.2.1 DC Resistance: The DC resistance of the s
22、ensor shall be less than 1500 .4.1.1.2.2 Typical Inductance: Typical sensor inductance shall be less than 360 mH.4.1.1.3 Electrical Isolation: The resistance between the signal wires (with signal and signal common shorted together) and the case shall be greater than 25 M 100 V DC.4.1.1.4 Phase Drift
23、: The phase drift is the variation of the sensors output voltage over time, when sensing a constant target speed under constant external environmental conditions. This variation is illustrated in Figure 3. The phase drift shall be less than 1 for pulse rates from 2 to 400 Hz.SAE AS5392 - 5 -FIGURE 3
24、 - Typical Passive Magnetic Sensor Phase Variation4.1.1.5 Sensor Pulse Rate: The sensor shall meet all the requirements stated in 4.1.1 when operating over a 2 to 400 Hz pulse rate.4.1.2 Interface Electronics Interface Requirements: The following subparagraphs give interface requirements for the ele
25、ctronics side of the sensor-to-electronics interface.4.1.2.1 Interface Electronics Input Voltage:4.1.2.1.1 Maximum Input Voltage for Usable Measurements: The maximum input voltage (Vsignal ) for which the interface electronics will operate normally shall be 60 V peak to peak. Input signals exceeding
26、 this maximum value may result in inaccurate results4.1.2.1.2 Maximum Non-damaging Input Voltage: The maximum input voltage (Vsignal ) that the interface electronics can withstand before suffering damage shall be 100 V peak to peak. Input signals exceeding this maximum may cause permanent damage to
27、the interface electronics.4.1.2.1.3 Minimum Usable Input Voltage: The minimum usable input voltage (Vsignal) shall be 1 V peak to peak (P-P).4.1.2.2 Interface Impedance: The interface electronics impedance, at the signal terminals, shall be greater than 15 k over the operating frequency range specif
28、ied in 4.1.2.4.SAE AS5392 - 6 -4.1.2.3 Maximum Noise: Noise is defined as any voltage that is present on the signal that is not part of the sensors nominal output. The noise content superimposed on the signal shall not exceed that shown in Figure 4 and shall not increase above 0.125 V peak for any f
29、requency. This maximum noise requirement applies to electrical factors only and not mechanical noise such as induced by mounting and external vibration.FIGURE 4 - Noise Spectrum4.1.2.4 Sensor Pulse Rate: The interface electronics shall process a pulse rate of 2 to 400 Hz.4.1.2.5 Electronic Trigger P
30、osition (V ref): The interface electronics shall trigger on the sensor output in one of two ways: 1) zero-crossing trigger; 2) non-zero, falling edge trigger level. In the case of the non-zero falling edge trigger level, the interface electronics shall trigger when the falling edge of the sensors ou
31、tput decreases through the DC reference voltage Vref = 0.6 V 0.005 V as shown in Figure 3. When using a zero crossing trigger, the electronics shall trigger in the middle of the bipulse, where the sensors output voltage changes sign. The triggering of the interface electronics indicates the position
32、 of the rotating element at that given time.4.2 Externally Powered Sensor Interface:Figure 5 shows the electrical interface for an externally powered sensor. The two models that are shown inside the sensor represent an open collector type output that switches between a high and low impedance state.
33、The power may be supplied by either the interface electronics or the aircraft power supply.SAE AS5392 - 7 -FIGURE 5 - Externally Powered Sensor Subsystem-to-Electronics Interface4.2.1 Sensor Interface Requirements: The externally powered sensors typically produce a series of rectangular shaped pulse
34、s whose amplitude, unlike the self-powered sensors, is not a function of the target speed. The following subparagraphs give interface requirements for the sensor side of the sensor-to-electronics interface.4.2.1.1 Sensor Impedance:4.2.1.1.1 Sensor “On-State” Impedance: The sensors “on-state” impedan
35、ce shall be less than 150 .4.2.1.1.2 Sensor “Off-State” Impedance: The sensors “off-state” impedance shall be high enough to ensure a maximum “off state” current of 50 A over the sensors signal voltage range.4.2.1.2 Sensor Signal Voltage (Vsignal):4.2.1.2.1 Maximum Sensor Signal Voltage: The maximum
36、 signal voltage (Vsignal ) shall be 30 V DC.4.2.1.2.2 Minimum Sensor Signal Voltage: The minimum signal voltage (Vsignal ) shall be -0.3 V DC.4.2.1.3 Maximum Sensor Signal Current: The maximum signal current (Isignal ) shall be 3 mA.4.2.1.4 Sensor Power:4.2.1.4.1 Sensor Operating Voltage (V power):
37、The sensor operating voltage shall be 28 V DC.4.2.1.4.2 Maximum Continuous Sensor Current (I power): The maximum continuous current shall be 100 mA.SAE AS5392 - 8 -4.2.1.4.3 Sensor Power Inrush Current: The inrush current shall be less than 150 mA.4.2.1.4.4 Power Quality: The sensor shall operate wi
38、th power quality as described by the power quality specification used for the aircraft in which the sensor is installed.4.2.1.5 Electrical Isolation: The resistance between the signal wires (with signal and signal common shorted together) and the case shall be greater than 25 M 100 V DC.4.2.1.6 Phas
39、e Drift: The phase drift is the variation in the sensors output voltage, over time, when sensing a constant target conditions. This variation is illustrated in Figure 6. The phase drift shall be less than 1 for pulse rates from 2 to 400 Hz.FIGURE 6 - Typical Phase Variation for the Digital Sensor4.2
40、.1.7 Sensor Pulse Rate: The sensor shall meet all the requirements stated in 4.2.1 when operating over a 2 to 400 Hz pulse rate.4.2.2 Interface Electronics Interface Requirements: The externally powered sensors electrical interface accepts a pulse train from the sensor as well as, optionally, provid
41、es electrical power to the sensor. The following subparagraphs give interface requirements for the electronics side of the sensor-to-electronics interface.4.2.2.1 Signal Voltage:4.2.2.1.1 Maximum Signal Voltage: The maximum electrical interface signal voltage (Vsignal ) shall not exceed 30 V DC.4.2.
42、2.1.2 Minimum Signal Voltage: The minimum electrical interface signal voltage (Vsignal ) shall be -0.3 V DC.SAE AS5392 - 9 -4.2.2.2 Maximum Signal Current: The maximum signal current (Isignal ) supplied by the interface electronics shall not exceed 1.5 mA.4.2.2.3 Minimum Rise/Fall Time: The minimum
43、signal rise time and fall time shall be 3.5 s, (0.5 degree phase at 400 Hz). Rise time is the time it takes the output voltage (Vsignal ) to rise from 10 to 90% of its final value. Fall time is the time it takes the output voltage (Vsignal ) to fall from 90 to 10% of its final value.4.2.2.4 Interfac
44、e Pulse Rate: The interface electronics shall process a pulse rate of 2 to 400 Hz.4.2.2.5 Electronic Trigger Position: The interface electronics shall trigger on the falling edge of the sensors output as shown in Figure 6. The triggering of the interface electronics indicates the position of the rot
45、ating element at that given time. The choice of a triggering threshold is left to the designer of the interface electronics who, in most cases, will also specify the value of the load/sense resistor and the excitation voltage.5. NOTES:5.1 Comments To Sensor Subsystem Designers:a. This document does
46、not specify the number of targets the sensor shall observe per revolution.b. To achieve interchangeability of self-powered sensors the 0.6 V crossing point (trigger position) must occur at the same mechanical index location regardless of which suppliers sensor is used.c. This specification does not
47、address the absolute phase of the sensors output signal. This is the responsibility of the system designer to mechanically mount and/or provide a software patch so that the sensors output switches at a meaningful point in time.d. The gap and target material shall be chosen by the system integrator s
48、o that both the requirements of this specification and interchangeability of interface electronics can be accomplished. e. During power switching transients it is acceptable for the indexing sensor and interfacing electronics to momentarily interrupt operation.f. The duration of time (or target revo
49、lutions) that the phase must be within 1 was not specified in 4.1.1.4. It is up to the system designer to ensure that the phase drifts less than 1 within the time span the data is collected for its intended purpose.SAE AS5392 - 10 -5.2 Principles of Operation - Different Sensor Technologies:5.2.1 Passive Magnetic Sensor: Passive magnetic speed sensors emit a magnetic field in front of the sensor. As a ferrous object approaches the tip of the sensor, the magnetic field increases and then decreases as the object moves away from
