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 entirely voluntary, and its applicability and suitability for any particular use, including any patent infringement arising theref
2、rom, 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 2010 SAE International All rights reserved. No part of this publication ma
3、y 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: +1 724-776-4970 (outside US
4、A) Fax: 724-776-0790 Email: CustomerServicesae.org SAE WEB ADDRESS: http:/www.sae.orgSAE values your input. To provide feedback on this Technical Report, please visit http:/www.sae.org/technical/standards/ARP5879AEROSPACERECOMMENDEDPRACTICEARP5879 Issued 2010-04Aerospace Test Methodology for Electro
5、hydrostatic Actuators RATIONALEThe test methodologies applicable to Electrohydrostatic Actuators (EHAs) require considerations unique to EHAs for certain requirements and tests, as compared to electrohydraulic servoactuators. This ARP discusses such tests specific to EHAs, and recommends test method
6、ologies unique to EHAs TABLE OF CONTENTS 1. SCOPE 31.1 Purpose . 31.2 Field of Application 32. REFERENCES 32.1 Applicable Documents 32.1.1 SAE Publications . 32.1.2 ISO Publications 42.2 Terminology 42.3 Abbreviations 43. TEST CONSIDERATIONS . 43.1 System Considerations . 43.2 Component Consideratio
7、ns 53.2.1 Power Drive Electronics (PDE) . 53.2.2 EHA Mechanical Components 53.2.3 Fluid Fill and Bleed, Integrity, Replenishment . 53.3 Test Fixture and Setup Considerations 63.3.1 Instrumentation . 63.3.2 Electric Power Supply . 63.4 Documentation 74. TESTS, THEIR SCOPE, AND METHODOLOGY . 74.1 Inte
8、gration Tests . 84.1.1 Performance Tests 84.1.2 Thermal Tests . 84.1.3 Failure Transients . 84.2 Acceptance Tests . 84.2.1 Examination of Product . 84.2.2 Software/Firmware Version Verification 84.2.3 Weight . 84.2.4 Proof Pressure 8SAE ARP5879 Page 2 of 204.2.5 Verification of Fill and Bleed . 94.2
9、.6 Performance Tests 104.2.7 Electrical Tests 144.3 Qualification Tests. 144.3.1 Proof Pressure (high temperature) . 154.3.2 High Temperature Performance . 154.3.3 Low Temperature Performance 154.3.4 Dynamic Stiffness . 164.3.5 Failure Transients . 164.3.6 Functional Tests 164.3.7 Duty Cycle Tests .
10、 164.3.8 Endurance Test . 174.3.9 Mechanical fatigue test . 184.3.10 Pressure Impulse 184.3.11 Limit Load 194.3.12 Environmental Tests . 194.3.13 Electrical Tests 194.3.14 Magnetic Effect . 204.3.15 Ultimate Load 204.3.16 Burst Pressure (high temperature) . 204.3.17 Fluid Integrity . 205. NOTES 20FI
11、GURE 1 EHA FLUID STIFFNESS TEST 10SAE ARP5879 Page 3 of 201. SCOPE This document provides an overview of the tests and issues related to testing that are unique to Electrohydrostatic Actuators (EHAs). An EHA incorporates a linear or rotary hydraulic actuator and a variable speed, reversible electric
12、 servomotor driving a fixed displacement hydraulic pump for actuator control, and associated power drive electronics. The tests and issues documented are not necessarily all-inclusive. This document discusses both, the tests applicable to EHAs and the test methodologies to accomplish the test object
13、ives. This document also lists tests that are not unique to EHAs, but are still applicable to EHAs. In these instances a discussion of such tests is not contained in this document, and as applicable, the reader may reference ARP1281 (Actuators: Aircraft Flight Controls, Power Operated, Hydraulic, Ge
14、neral Specification For), which addresses test issues applicable to electrohydraulic flight control servoactuators. In the discussion of the tests and test methodologies contained in this document, numerical definition or specification of the test parameters to be imposed or measured is not included
15、. These definitions or specifications should be developed to conform to the requirements of the applicable EHA technical specification document, considering the usual influencing factors such as instrumentation accuracy, test temperature, etc. 1.1 Purpose The purpose of this document is to facilitat
16、e the generation of test specifications, plans and procedures for EHAs (and EHA mode operation of Electric Backup Hydraulic Actuators (EBHAs), covering Integration, Acceptance and Qualification testing.1.2 Field of Application This document focuses on EHA issues irrespective of the application of th
17、e EHA whether military or commercial. It shall be the users responsibility to ensure that particular qualification or certification requirements, or applicable specifications, standards or regulations for the intended application are satisfied by the EHA design, and the tests and test methods that a
18、re developed. 2. REFERENCES 2.1 Applicable Documents The following publications form a part of this document to the extent specified herein. The latest issue of SAE publications shall apply. The applicable issue of other publications shall be the issue in effect on the date of the purchase order. In
19、 the event of conflict between the text of this document and references cited herein, the text of this document takes precedence. Nothing in this document, however, supersedes applicable laws and regulations unless a specific exemption has been obtained. 2.1.1 SAE Publications Available from SAE Int
20、ernational, 400 Commonwealth Drive, Warrendale, PA 15096-0001, Tel: 877-606-7323 (inside USA and Canada) or 724-776-4970 (outside USA), www.sae.org.ARP1281 Actuators: Aircraft Flight Controls, Power Operated, Hydraulic, General Specification For ARP1383 Impulse Testing of Aerospace Hydraulic Actuato
21、rs, Valves, Pressure Containers, and Similar Fluid System Components ARP4386 Terminology and Definitions for Aerospace Fluid Power, Actuation and Control Technologies ARP5007 Development Process - Aerospace Fly-By-Wire Actuation System AS4941 Aerospace - General Requirements for Commercial Aircraft
22、Hydraulic ComponentsSAE ARP5879 Page 4 of 20AS8775 Hydraulic System Components, Aircraft and Missiles, General Specification For 2.1.2 ISO Publications Available from American National Standards Institute, 25 West 43rdStreet, New York, NY 10036-8002, Tel: 212-642-4900, www.ansi.org, or from Internat
23、ional Organization for Standardization, 1, rue de Varembe, Case postale 56, CH-1211 Geneva 20, Switzerland, Tel: +41-22-749-01-11, www.iso.org.ISO22072 Aerospace Electrohydrostatic actuator (EHA) Characteristics to be defined in procurement specifications 2.2 Terminology Refer to ARP4386 and ISO2207
24、2 for EHA specific terminology. 2.3 Abbreviations Following abbreviations are used in this document. ATP Acceptance Test Procedure BIT Built-In-Test CE Control Electronics EHA Electrohydrostatic Actuator EHAS Electrohydrostatic Actuation System EBHA Electrical Backup Hydraulic Actuator ICD Interface
25、 Control Document IAP Integrated Actuator Package PDE Power Drive Electronics SOV Solenoid Operated Valve 3. TEST CONSIDERATIONS 3.1 System Considerations The performance of an EHA is heavily dependent upon the associated electronics both the power drivers for the electric motor, as well as the vari
26、ous control loop closures. The EHA by definition includes the power drive electronics (PDE; whether mounted locally on the actuator itself, or at a remote location), ref. ARP4386 or ISO22072. The control electronics (CE) by definition are not a part of the EHA (an EHA along with its CE is the Electr
27、oHydrostatic Actuation System (EHAS). While this definition of an EHA facilitates isolation of the discussion of the critical EHA elements involved in power transmission, physical separation between PDE and CE may or may not be distinct.This document is intended to discuss issues related to testing
28、of the EHA and includes issues related to the PDE. While this document is not intended to discuss issues related to the CE, it is to be recognized that the planning and execution of several, if not most, tests on an EHA needs to be undertaken with full consideration of the impact that the CE used to
29、 test the EHA will have on the EHA under test. SAE ARP5879 Page 5 of 20For example, the electric motor driven EHA has performance capability dependent upon the motor capability, the capability of the power driver and the supply voltage, power control algorithms built into the power drivers or contro
30、l electronics, and all loop closures around the power driver, the motor and the EHA. Similarly, the failure transient performance of the EHA is dependent upon the performance of any mode select valves within the EHA, the electrical energization/de-energization of electrically actuated mode select va
31、lves and the motor, and the control algorithms that govern various EHA functions. As such, in all those instances where an EHA is subjected to a test that necessitates electronics for its function and the electronics have an impact on the performance of the EHA, the electronics will be either(a) The
32、 actual electronics to be used with the actuator,or(b) Test electronics that are used to test the EHA, which shall be validated separately and independently as being of the required configuration and capability, to ensure accurate EHA test results. Such electronics may be termed validated electronic
33、s (or validated test consoles). 3.2 Component Considerations 3.2.1 Power Drive Electronics (PDE) A critical safety consideration in handling the PDE in a test environment is to ensure that the DC link and EMI capacitors are discharged before handling the unit. While a typical PDE contains bleed resi
34、stors or other devices to ensure the internal charge on capacitors has been depleted, the time over which the discharge occurs can vary, and in the event of failure of the bleed device, may not discharge at all. It is imperative that before handling the PDE, the voltage from source to return be veri
35、fied to be at a safe level, usually below 30 volts. 3.2.2 EHA Mechanical Components In addition to the usual importance of component cleanliness prior to assembly for electrohydraulic servoactuators, EHA mechanical components require additional considerations. Due to the relatively small, closed hyd
36、raulic circuit of EHAs, ensuring that components are adequately clean prior to assembly and any re-assembly during a test program is very important to preclude adverse impact to EHA fluid cleanliness and integrity. For any disassembly that may be required during a test program, the disassembly proce
37、dure should carefully consider minimizing fluid loss, and recovery, storage and reuse, or replenishment of any fluid that may be lost. An important safety consideration in disassembly of the EHA in a test environment is to ensure that the EHA reservoir is depressurized or discharged before opening t
38、he hydraulic circuit of the unit. 3.2.3 Fluid Fill and Bleed, Integrity, Replenishment 3.2.3.1 Fluid Fill and Bleed Proper filling and bleeding of the EHA is crucial to its performance. A fill and bleed test procedure and tooling/fixtures are often developed to ensure adequate fill and bleed. Prior
39、to beginning EHA tests and as necessary during an extended test program, it should be verified that the EHA has been adequately filled and bled. 3.2.3.2 Fluid Integrity In an extended test program, the need to monitor the condition of the EHA fluid periodically should be examined. The method to obta
40、in a sample of the EHA fluid, and its replenishment if required, should be established. SAE ARP5879 Page 6 of 203.2.3.3 Fluid replenishment In an extended test program, the EHA fluid may need to be replenished due to external leakage, or due to the fluid lost during disassembly and reassembly that m
41、ay be required of the mechanical components. The test program should address the implications of such replenishment. Cleanliness of the fluid used for replenishment should be in compliance with the applicable EHA specification. 3.2.3.4 Other Considerations Depending upon the design of the EHA, some
42、specific tests such as those that result in an internal temperature increase, could cause excessive internal pressurization or overboard EHA fluid loss. In such cases, unless such internal pressurization or overboard fluid loss is intended, consideration should be given to conducting such tests with
43、 the EHA reservoir partially filled. 3.3 Test Fixture and Setup Considerations In addition to the usual considerations given to the design of the required test fixtures and setups for electrohydraulic servoactuators, EHA test fixtures and setups may require additional issues to be addressed dependin
44、g upon the planned tests. The following is an illustrative list of such considerations: x Environmental considerations for the required heat transfer for the EHA including the PDE. The considerations or requirements may not be the same for both the actuator and the PDE. x Endurance and duty cycle te
45、sting: Need for synchronizing the load system to EHA commands and/or PDE operating parameters.x Duty cycle testing: Worst case requirements for the EHA actuator may or may not be the worst case for the PDE. May need separate tests for each. x The rate at which EHA endurance testing is conducted may
46、be impacted by the EHA and/or electronics temperatures. x Consideration of undertaking EHA actuator endurance test with validated electronics instead of the PDE. x Careful consideration of performance test stress on the actuator and the PDE. Due to losses such as the motor and the PDE electrical los
47、ses and the energy required to accelerate/decelerate the motor-pump inertia, the duration of testing such as stall force and frequency response, among others, may need to be limited to avoid causing thermal damage to the motor or the PDE. 3.3.1 Instrumentation During certain tests it may be necessar
48、y to install sensors in addition to the sensors that may already be a part of the EHA. Consideration of such sensors should ensure that the sensors or their attachment hardware do not impact the EHA function or performance in a manner that may invalidate the test. 3.3.2 Electric Power Supply The electric power supply system used during EHA testing should be sufficiently representative of the power supply of the intended application of the EHA. As such it should conform to several important requirements.
