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 there
2、from, is the sole responsibility of the user.” SAE reviews each technical report at least every five years at which time it may be revised, reaffirmed, stabilized, or cancelled. SAE invites your written comments and suggestions. Copyright 2016 SAE International All rights reserved. No part of this p
3、ublication 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: +1 724-776-497
4、0 (outside USA) Fax: 724-776-0790 Email: CustomerServicesae.org SAE WEB ADDRESS: http:/www.sae.org SAE values your input. To provide feedback on this Technical Report, please visit http:/standards.sae.org/AIR1739B AEROSPACE INFORMATION REPORT AIR1739 REV. B Issued 1981-08 Revised 2012-02 Reaffirmed
5、2016-11 Superseding AIR1739A Information on Antiskid Systems RATIONALE AIR1739B has been reaffirmed to comply with the SAE five-year review policy. INTRODUCTION The summary of experience in antiskid system usage will be used by design personnel to avoid the pitfalls experienced by others in applicat
6、ion of antiskid to retrofitted and new systems. The information will be presented as General System Description and Operation, Hardware Details and Functions, System Performance Evaluation, System Development Process, and Service Problems. Need and Requirements: While antiskid system, component, and
7、 feature problems and limitations are well known to the designer and specific user, there is no documentation available which describes the broad field of applications. This document is a compendium of field experience and can form the basis for establishing system requirements. The requirements sho
8、uld reflect the intended operating surfaces, the desired performance, required system efficiency and the method of determining this efficiency. Required system characteristics or features should be initially established along with performance requirements prior to contracting for a system. Antiskid
9、control systems originated in response to the inability of the pilot to maintain control of the brake system and to avoid inadvertent wheel lockup and possible tire failure. With most power brake systems, the “feel“ of the overall aircraft system to the pilot is inadequate to maintain knowledge of t
10、he state of rotation of all the aircraft wheels. This is especially true for large multi-wheel aircraft. Therefore, some degree of assistance was needed to detect and react to deep skids and wheel lockups. This initial basic need resulted in the inclusion of an antiskid system. As antiskid systems e
11、volved, their primary purpose shifted from lockup prevention and tire saving to optimal stopping performance. All modern brake control systems include highly efficient stopping performance as one of their primary goals. TABLE OF CONTENTS 1. SCOPE 51.1 Purpose . 52. APPLICABLE DOCUMENTS 52.1 SAE Publ
12、ications . 52.2 U.S. Government Publications 52.3 Other Documents 63. GENERAL SYSTEM DESCRIPTION AND OPERATION 63.1 General System Configuration 63.2 System Operation . 63.3 Antiskid Control Classification . 63.3.1 ON-OFF Systems 73.3.2 Modulating (Quasi-Modulating) Systems 83.3.3 Adaptive Systems (
13、Fully Modulating) 83.4 Control Features . 113.4.1 Individual Wheel Control . 113.4.2 Paired Wheel Control 123.4.3 Locked Wheel Protection 123.4.4 Touchdown Protection 123.4.5 Hydroplaning Protection 123.4.6 Fault Detection 124. HARDWARE DETAILS AND FUNCTIONS 134.1 Wheel Speed Transducer . 134.1.1 DC
14、 Generator 134.1.2 AC Generator 134.1.3 Fiber-Optic Wheel Speed Transducers 144.1.4 Wheel Speed Transducer Couplings 144.1.5 Sensor/Exciter Ring, Wheel Speed Transducers . 154.1.6 Hall Effects Wheel Speed Transducers 164.2 Controller . 184.3 Antiskid Valve 184.4 Electric Brake Actuation 194.5 Brake
15、and Tire . 205. SYSTEM PERFORMANCE EVALUATION 245.1 Aircraft Tests . 255.1.1 Average Friction Coefficient Calculation - Basic Method 255.1.2 Antiskid System Efficiency Calculation - Drag Force/Torque/Pressure Efficiency Method 285.1.3 Antiskid System Efficiency Calculation - Wheel Slip Method . 295.
16、2 Simulator Tests . 315.2.1 Stopping Distance Efficiency 325.2.2 Developed Efficiency . 335.2.3 Developed Efficiency - Alternate Method 1 345.2.4 Developed Acceleration Efficiency . 365.3 Dynamometer Tests 376. SYSTEM DEVELOPMENT PROCESS 38SAE INTERNATIONAL AIR1739B 2 of 56_7. SYSTEM ISSUES . 407.1
17、Actuator/System Response 407.1.1 Long Hydraulic Lines 407.1.2 Line Diameter 437.1.3 Restrictions in Brake Lines . 437.1.4 Flex Lines 437.1.5 Brakes with Excessive Compliance 437.1.6 Air in the System/Low Return Pressure 437.1.7 Hydraulic Line Bends and Routing . 437.1.8 Valves With Inadequate Flow C
18、apacity 447.1.9 Inadequate Hydraulic Supply 447.1.10 Inadequate Hydraulic Return 447.1.11 Poor Brake Metering Valve Response 447.1.12 Contaminated Hydraulic Fluid . 447.1.13 Electric Actuator Response . 447.2 Excessive Brake Torque Gain 457.3 Poor Aerodynamic Lift Dumping . 457.4 Hydroplaning . 457.
19、5 Landing Gear 467.5.1 Locked Out Main Gear Suspension 467.5.2 Forward Raked Main Landing Gears 537.5.3 Gear Shimmy 547.6 Changes Without Consultation . 548. SERVICE PROBLEMS . 559. NOTES 55FIGURE 1 ANTISKID SYSTEM SCHEMATIC . 7FIGURE 2 ON-OFF SYSTEM OPERATION 9FIGURE 3 MODULATING SYSTEM OPERATION 1
20、0FIGURE 4 ADAPTIVE SYSTEM OPERATION 11FIGURE 5 DC WHEEL SPEED TRANSDUCER 13FIGURE 6 AC WHEEL SPEED TRANSDUCER 14FIGURE 7 SPIDER/DOG-BONE COUPLING 15FIGURE 8 BELLOWS COUPLING . 15FIGURE 9 SENSOR - EXCITER RING 16FIGURE 10 AXLE RDC, BLOW UP . 17FIGURE 11 AXLE RDC, SIDE VIEW 17FIGURE 12 ANTISKID SERVO
21、VALVE (3-WAY) 19FIGURE 13 ELECTRIC BRAKES . 19FIGURE 14 ELECTRIC BRAKE ACTUATOR (FIRST GENERATION) . 20FIGURE 15 TYPICAL AIRCRAFT BRAKE ASSEMBLIES . 21FIGURE 16 MU VS SLIP CURVE 21FIGURE 17 TIRE PULLEY ANALOGY . 22FIGURE 18 TYPICAL AIRCRAFT TIRE CONSTRUCTION (BIAS) . 23FIGURE 19 TYPICAL AIRCRAFT TIR
22、E CONSTRUCTION (RADIAL) 23FIGURE 20 AIRCRAFT LANDING GEAR GEOMETRY 27FIGURE 21 BRAKE TORQUE/PRESSURE/DRAG FORCE EFFICIENCY . 29FIGURE 22 ANTISKID EFFICIENCY VERSUS WHEEL SLIP RATIO 30FIGURE 23 OPTIMUM SLIP RATIO DETERMINATION . 31FIGURE 24 TIRE FREE BODY DIAGRAM 35FIGURE 25 MU-SLIP AND MU ROLL 35FIG
23、URE 26 EFFICIENCY FOR AN ACCELERATING AIRCRAFT 37FIGURE 27 BRAKE DISPLACEMENT CURVE . 41FIGURE 28 BRAKE PISTON AND STACK 41FIGURE 29 WATER HAMMER 42FIGURE 30 FLAPPER-NOZZLE CONTAMINATION . 44SAE INTERNATIONAL AIR1739B 3 of 56_FIGURE 31 SHOCK STRUT WITH A STEP 46FIGURE 32 SHOCK STRUT BEARING LOADS 47
24、FIGURE 33 WEIGHT ON THE WHEEL WITH A STICKING SHOCK STRUT 47FIGURE 34 WEIGHT ON THE WHEEL VERSUS TIME 48FIGURE 35 WEIGHT ON THE WHEEL VERSUS MU VARIATIONS 49FIGURE 36 WHEEL SPEED VARIATION DUE TO BOUNCING 49FIGURE 37 BOUNCING FOOLS BRAKE CONTROL (TIGHT CONTROL) 50FIGURE 38 BOUNCING FOOLS BRAKE CONTR
25、OL (TUNED FOR BOUNCING) 52FIGURE 39 GEAR ACCELERATION AFTER DEEP SKID RELEASE 53FIGURE 40 FORWARD AND AFTWARD RAKED GEAR . 53TABLE 1 AIRPLANE AND LANDING GEAR PARAMETERS . 39APPENDIX A BIBLIOGRAPHY . 56SAE INTERNATIONAL AIR1739B 4 of 56_1. SCOPE This SAE Aerospace Information Report (AIR) has been p
26、repared by a panel of the SAE A-5A Committee and is presented to document the design approaches and service experience from various applications of antiskid systems. This experience includes commercial and military applications. 1.1 Purpose The purpose of this document is to describe antiskid system
27、 configurations, features, modes of operation and to define various methods used to calculate antiskid system performance. 2. 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
28、issue of other publications shall be the issue in effect on the date of the purchase order. In 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 regulation
29、s unless a specific exemption has been obtained. 2.1 SAE Publications Available from SAE International, 400 Commonwealth Drive, Warrendale, PA 15096-0001, Tel: 877-606-7323 (inside USA and Canada) or 724-776-4970 (outside USA), www.sae.orgAS483B Skid Control Equipment AIR764C Skid Control System Vib
30、ration Survey ARP862B Skid Control Performance AIR1064D Braking System Dynamics ARP1070C Design and Testing of Antiskid Brake Control Systems for Total Aircraft Compatibility AIR5372 Information on Brake-by-Wire (BBW) Brake Control Systems 2.2 U.S. Government Publications Available from the Document
31、 Automation and Production Service (DAPS), Building 4/D, 700 Robbins Avenue, Philadelphia, PA 19111-5094, Tel: 215-697-6257, http:/assist.daps.dla.mil/quicksearch/14 CFR 25.735e Antiskid Systems 14 CFR 25.109 Accelerate-Stop Distance 14 CFR 25.1301 Function and Installation 14 CFR 25.1309 Equipment,
32、 Systems and Installations AC 25-7B Flight Test Guide for Certification of Transport Category Airplanes AC 25.735-1 Brakes and Braking Systems Certification Tests and Analysis MIL-W-5013L Military Specification Wheel and Brake Assemblies, Aircraft General Specification for MIL-PRF-5041K Performance
33、Specification, Tires, Ribbed Tread, Pneumatic, Aircraft, General Specification for MIL-B-8075D Brake Control Systems, Antiskid, Aircraft Wheels, General Specification for SAE INTERNATIONAL AIR1739B 5 of 56_2.3 Other Documents AFFDL-TR 74-118 “Test and Performance Criteria for Airplane Antiskid Syste
34、ms,“ October 1974 Boeing Report D6-41115, “Research Study on Antiskid Braking Systems for the Space Shuttle,“ NASA Contract 8-27864 ASD-TR-74-41, FAA-RD-74-211, Vols. I and II, “Combat Traction II, Phase II,“ October 1974 ASD-TR-77-6, Vols. I and II, “An Extended Prediction Model for Airplane Brakin
35、g Distance and a Specification for a Total Braking Prediction System,“ March 1977 NASA TP-1051, “Behavior of Aircraft Antiskid Braking Systems on Dry and Wet Runway Surfaces - A Slip-Velocity-Controlled, Pressure-Bias-Modulated System”, December 1979 NLR-TP-2001-242, “Hydroplaning of Modern Aircraft
36、 Tires,” Nationaal Lucht- en Ruimtervarrtlaboratorium NLR, November 1999 3. GENERAL SYSTEM DESCRIPTION AND OPERATION 3.1 General System Configuration Antiskid Control System is defined as a group of interconnected components which interact to prevent inadvertent tire skidding and contribute to short
37、er aircraft stopping distances by controlling excessive clamping force on the brakes. The basic system normally consists of a wheel speed transducer, a control circuit and a brake pressure control valve or electric motor actuation controller as shown in Figure 1. The antiskid system is a sub-system
38、of the braking system which also includes the pilot control, parking brake functions, and the wheel/tire/brake assemblies. The braking system may also include other features such as automatic and gear retract braking. In some cases, the pilots control function uses the antiskid system hardware, as i
39、s the case in many brake-by-wire systems. All are subsystems of the gear, and they are all interrelated.3.2 System Operation The basic purpose of the antiskid system is to modulate pilot commanded clamping force on the brakes, modulating it to levels compatible with optimum aircraft deceleration, wh
40、ile preventing excessive wheel skidding. In hydraulic systems this clamping force is produced by hydraulically driven pistons. In electric brake systems this force is produced by electrically driven actuators. Typical operation is as follows. The pilot applies brakes by applying force to the brake p
41、edals resulting in an increase in clamping force in the brakes. As the clamping force increases, the wheel begins to slow down and the force between the tire and the runway increases. When the available friction force between the tire and the runway is exceeded, the wheel begins to decelerate rapidl
42、y. This is sensed by the antiskid system which in response outputs a signal to reduce clamping force. With release of clamping force, the wheel accelerates to a speed somewhat less than synchronous speed while maintaining as much braking force as possible, the release signal is removed and clamping
43、force is reapplied. This sequence then repeats as needed. 3.3 Antiskid Control Classification Many different antiskid systems are in use today. They represent a broad spectrum of an evolving technology from the late 1940s and different approaches to the solution of a complex problem. The very early
44、systems utilize on-off control concepts, while later systems provide different degrees of brake pressure modulation in response to wheel speed changes.SAE INTERNATIONAL AIR1739B 6 of 56_FIGURE 1 - ANTISKID SYSTEM SCHEMATIC 3.3.1 ON-OFF Systems A typical on-off system is in use on the B-52 and consis
45、ts of three components: a skid and locked wheel detector, a control shield, and a solenoid valve. The detector is an electro-mechanical device, providing logic signals to the control shield. The control shield is a power conditioner containing a series of relays. The relays interpret logic signals f
46、rom the detector and apply an electrical signal to the hydraulic solenoid valve, to dump or reapply metered brake pressure. The detector is the heart of this antiskid system. Its function in the system is to detect wheel decelerations above a preset value. As implemented in the B-52, the detector is
47、 mounted in the axle and is driven by wheel hub cap rotation. The skid sensing portion of the detector consists of an inertia flywheel and an overload-release clutch. The flywheels inertia causes the spring loaded clutch to release when wheel deceleration exceeds a predetermined rate. Because the wheel is slowing down faster than the released inertia, a relative displacement occurs between the inertia and the drive, attached to the wheel, causing a set of electrical points to contact, thereby completing the skid circuit to the control shield. The s
