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 reaffirmed, revised, or cancelled. SAE invites your written comments and suggestions. Copyright 2009 SAE International All rights reserved. No part of this publication m
3、ay 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 (outside USA)
4、 Fax: 724-776-0790 Email: CustomerServicesae.org SAE WEB ADDRESS: http:/www.sae.org SURFACE VEHICLE RECOMMENDED PRACTICE J1843 MAY2009 Issued 1989-06 Revised 2009-05 Superseding J1843 APR1993 Accelerator Pedal Position Sensor for Use with Electronic Controls in Medium- and Heavy-Duty Vehicle Applica
5、tionsTruck and Bus RATIONALE The following changes have been made to the document: Sec. 4: Sensors integrated into the pedal unit may not require an additional return force mechanism. Sec. 6: Specified each signal channel for Dual APS throttle pedal sensors. Sec. 6.9: Hysteresis requirement should b
6、e a valid statement over the entire span. Sec. 6.10 and 6.11: Specify that the open or short circuit response is valid at any position. Sec. 7.2: Changed to 40 mA DC maximum from 100 V DC maximum. Sec. 7.6: Added reference to Figure 2 for output linearity. Sec. 7.8: Corrected grammar. Sec. 7.10: Hys
7、teresis requirement should be a valid statement over the entire span. Sec. 7.11 and 7.12: Specify that the open or short circuit response is valid at any position. FOREWORD Many electronic controls used in medium- and heavy-duty vehicles require an electrical indication of accelerator pedal position
8、. A common accelerator pedal position sensor function and performance criterion is desired to minimize the number of different designs that would have to be stocked by those who service the many different types and brands of vehicles. A single universal electrical interface has not been defined. Two
9、 electrical interface types are defined in this SAE Recommended Practice. The intent of providing a choice of two signal types is to allow the industry time to prove by actual application the best selection. While a common mechanical definition of the size, shape, etc., of the accelerator pedal and
10、accelerator position sensor is desirable, it is realized that vehicles are not designed around the accelerator pedal. The present variations in vehicle configurations and design requirements cannot be satisfied by a single mechanical interface specification for the accelerator pedal. The intent of t
11、his specification is to limit sensor variations to one physical mounting interface and one of two electrical signal types. The specification to outline portions of the physical interface between an accelerator pedal and the accelerator pedal position sensor should serve two purposes. First, it will
12、minimize the number of base mechanical pedals required to mount the appropriate sensor(s) for different applications. Second, this specification would encourage the use of the sensors with the same mechanical interface for floor-mounted, suspended, and remote accelerator applications. For the remain
13、der of this document, the term “pedal“ can be construed to mean any physical means of converting operator motion into an acceleration or deceleration command. SAE J1843 Revised MAY2009 Page 2 of 19 1. SCOPE The purpose of this SAE Recommended Practice is to provide a common electrical and mechanical
14、 interface specification that can be used to design electronic accelerator pedal position sensors and electronic control systems for use in medium- and heavy-duty vehicle applications. 2. REFERENCES 2.1 Applicable Publication The following publication forms a part of this specification to the extent
15、 specified herein. The latest issue of SAE publications shall apply. 2.1.1 SAE Publication 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.org. SAE J1455 Recommended Environmental Pr
16、actices for Electronic Equipment Design in Heavy-Duty Vehicle Applications 2.1.2 The APS assembly shall comply with all appropriate Federal Motor Vehicle Safety Standards. 3. DEFINITIONS 3.1 Accelerator Position Sensor (APS) The sensor portion of the physical device used to convert the accelerator p
17、osition into an electrical signal. 3.2 Diagnostic Ranges The ranges of APS outputs between the maximum allowable output span during normal operation and the APS output values specified as an indication of an absolute fault condition. APS outputs in the diagnostic ranges may be used by the controller
18、(s) as an out-of-range indication, but do not necessarily indicate an absolute fault. 3.3 Duty Cycle The ratio of signal time high to signal period (see Figure 1). 3.4 Electrical Interface The electrical signals to be passed from the APS to other electronic/electrical devices. 3.5 Fault Ranges The r
19、anges of the APS output values beyond the diagnostic range(s) that indicate an absolute fault condition in the accelerator pedal assembly. 3.6 Full Scale The difference between the theoretical maximum and minimum signal outputs (i.e., 100% of analog supply voltage or 100% duty cycle). 3.7 Mechanical
20、 Interface The physical boundaries of the APS. SAE J1843 Revised MAY2009 Page 3 of 19 3.8 Output Hysteresis The maximum output signal difference for a given input pedal position due to previous history of pedal motion in either the increasing or decreasing direction. 3.9 Output Linearity The maximum
21、 deviation of the actual output transfer function from a straight line defined by the best fit linear regression straight line through the actual values (see Figure 2). 3.10 Output Smoothness Any spurious variation in the output not present in the input is measured as the difference between the actu
22、al output transfer function and the end points of a 2.0% of total pedal travel long line parallel to the output linearity function that passes through the actual output value for any APS position. The difference between the actual output values and the parallel line end points located 1.0% of total
23、travel from the APS position should be less than the output smoothness specification (see Figure 3). 3.11 Pulse Width Modulated (PWM) A system of modulation where the duty cycle of discrete pulses are varied by controlling the leading, trailing, or both edges to represent an output signal where the
24、duty cycle of the pulse is proportional to the value represented. 3.12 Sensing Element The portion of, or discrete device contained within, the APS that converts physical motion into a usable electrical signal. 3.13 Supply Voltage The voltage measured between the +V supply and V supply leads with th
25、e APS device connected. 3.14 Treadle The lever operated by the foot. 3.15 Idle Validation Signal (IVS) A signal generated by the accelerator pedal assembly to indicate that the assembly is in the idle position. SAE J1843 Revised MAY2009 Page 4 of 19 FIGURE 1 - PULSE WIDTH MODULATED SIGNAL WAVEFORM S
26、AE J1843 Revised MAY2009 Page 5 of 19 FIGURE 2 - OUTPUT LINEARITY DEFINITION SAE J1843 Revised MAY2009 Page 6 of 19 FIGURE 3 - OUTPUT SMOOTHNESS DEFINITION 3.16 Transmission Shift Point Transition Signal The electrical signal used by an automatic transmission to provide early shift points at low thr
27、ottle and higher shift points at increased throttle positions. 3.17 Kick Down Signal The electrical signal used by an automatic transmission to raise the shift points to provide maximum performance at full throttle. 4. MECHANICAL INTERFACE The following specifications are for an accelerator pedal to
28、 accelerator position sensor interface. It is intended to allow the design of sensors that are interchangeable for different electronic applications. The driveshaft configuration and APS mounting pattern are the critical areas for commonality. Figure 4 outlines the mounting pattern and driveshaft or
29、ientation. SAE J1843 Revised MAY2009 Page 7 of 19 FIGURE 4 - APS MOUNTING SPECIFICATIONS SENSOR MOUNTING HOLE PATTERN AND ANGULAR ROTATION REQUIREMENTS SAE J1843 Revised MAY2009 Page 8 of 19 Figure 5 outlines the APS mechanical interface in the area around the APS driveshaft. Figure 5 is a view from
30、 section A-A of Figure 4. Overall drift of the minimum accelerator pedal position driveshaft to be 3 degrees over the operating life of the accelerator pedal. Overall drift of the maximum accelerator pedal position driveshaft to be 3 degrees over the operating life of the accelerator pedal. Due to v
31、ariations in actual pedal designs and applications, sources of auxiliary signals, as defined in Section 8, may utilize, but are not required to utilize, this APS-to-pedal mechanical interface. If the APS has an optional cutaway driveshaft receptacle as illustrated in Figure 6, then the APS must not
32、contain an integral IVS. In this case, if the IVS is required, it must be located and operated independently of the APS. The APS shall contain an internal source of energy capable of returning the internal portions of the APS to the end of travel nearest the idle state. It is not intended that the A
33、PS be capable of returning the entire accelerator pedal assembly to an idle condition. The accelerator pedal assembly is expected to accomplish return of the treadle through other sources of energy. When the APS is an integrated part of the pedal unit, this internal source of energy may not be requi
34、red. FIGURE 5 - APS MOUNTING SPECIFICATIONS SECTION A-A SAE J1843 Revised MAY2009 Page 9 of 19 FIGURE 6 - OPTIONAL SENSOR CUTOUT 5. ELECTRICAL INTERFACE Any one electrical output signal of the accelerator pedal assembly is intended to be used by only one recipient device (i.e., electronic engine con
35、trol only, or electronic transmission control only). If multiple devices require a reliable signal from the APS, then some manner of isolation and buffering of the APS signal should be provided to each device, to prevent the loss of the APS signal if a fault occurred in only one subsystem. Two optio
36、nal electrical interfaces are defined. Either Option A, an analog ratiometric signal or Option B, a pulse width modulated (PWM) electronic interface can be used. The two options are presented and both are presently used in the industry today. An APS is not expected to provide both Option A and Optio
37、n B output signals, nor is the recipient device expected to be compatible with both. 6. ANALOG RATIOMETRIC ELECTRONIC INTERFACE (OPTION A) The following specifications for each signal channel shall apply when an analog ratiometric electronic interface is used in the APS. 6.1 Supply Voltage 5.0 V DC
38、0.50 V DC. 6.2 Supply Current 20 mA maximum. SAE J1843 Revised MAY2009 Page 10 of 19 6.3 Output Range See Figure 7. a. Span = 67.5% 7.5% of supply voltage b. Minimum APS Position = 15% 5% of supply voltage c. Maximum APS Position = 77.5% 7.5% of supply voltage 6.4 Diagnostic Range See Figure 7. a. L
39、ower Range = Less than 10% of supply voltage b. Upper Range = Greater than 85% of supply voltage 6.5 Fault Range See Figure 7. a. Lower Range = Less than 5% of supply voltage b. Upper Range = Greater than 90% of supply voltage FIGURE 7 - ANALOG RATIOMETRIC OUTPUT TRANSFER FUNCTION SAE J1843 Revised
40、MAY2009 Page 11 of 19 6.6 Output Smoothness 0.5% of full scale output for any 2% interval of total travel over the output range (See Figure 3). 6.7 Output Linearity 5% of full scale output over the output range. 6.8 Output Current The output transfer function defined in Figure 7 is to be valid under
41、 an electrical test load of 47 k 5%. (See Figure 8). FIGURE 8 - RATIOMETRIC APS OUTPUT TEST CIRCUIT 6.9 Output Hysteresis The sensing device must not exhibit output hysteresis greater than 2% of full scale output when measured over the entire span. Output hysteresis is measured at the direct mechani
42、cal input to the accelerator pedal position sensing element. Hysteresis of the linkages between the treadle and the sensing element of the APS is not included. 6.10 Open Circuit Response An open circuit of any lead to the APS at any position shall result in a signal as measured across the test point
43、s (47 k 5% test lead as per Figure 8) within a specified fault range as shown in Figure 7 and within a maximum time of 1.0 s. The signal shall transit from a specified fault range signal to the correct reading at any APS position in less than 0.1 s (signal slew rate only) upon return to a normal ope
44、ration. 6.11 Short Circuit Response A short circuit between any two leads of the APS at any position shall result in a signal as measured across the test points (47 k 5% load as per Figure 8) within a specified fault range as shown in Figure 7 and within a maximum time of 1.0 s. The signal shall tra
45、nsit from a specified fault range signal to the correct reading at any APS position in less than 0.1 s (signal slew rate only) upon return to a normal operation. SAE J1843 Revised MAY2009 Page 12 of 19 7. PULSE WIDTH MODULATED (PWM) ELECTRONIC INTERFACE (OPTION B) The following specifications shall
46、apply when a pulse width modulated electronic interface, Figure 1, is used in the APS. 7.1 Supply Voltage Positive battery voltage, 12 V DC or 24 V DC nominal, regulated 8 V DC 0.4 V DC, or regulated 5 V DC 0.25 V DC. 7.2 Supply Current 40 mA DC maximum. 7.3 Output Range See Figure 9. a. Minimum APS
47、 Position = 6% duty cycle b. Maximum APS Position = 94% duty cycle c. Minimum Accelerator Assembly Position = 16% 6% duty cycle d. Maximum Accelerator Assembly Position = 82.5% 7.5% duty cycle 7.4 Fault Range See Figure 9. a. Lower Range = Less than 5% duty cycle b. Upper Range = Greater than 95% du
48、ty cycle 7.5 Output Smoothness 0.5% of full scale output for any 2% interval of total travel over the output range (See Figure 3). 7.6 Output Linearity 5% of full scale output over the output range (See Figure 2). 7.7 Output Frequency a. Minimum = 200 Hz b. Maximum = 1100 Hz 7.8 Output Current The o
49、utput transfer function as defined in Figure 9 is to be valid under an electrical test load impedance of 47 k 5% and 0.001 F capacitance. See Figure 10 for test schematic. The output voltage across the test points high shall be greater than 3.8 V while sourcing a minimum 8.0 mA current. The output voltage low shall be less than 1.0 V while sinking a maximum 10 mA current. SAE J1843 Revised MAY2009 Page 13 of
