《GMW-8773-2006.pdf》由会员分享,可在线阅读,更多相关《GMW-8773-2006.pdf(34页珍藏版)》请在三一文库上搜索。
1、 WORLWIDE ENGINEERING STANDARDS General Specification Electrical/Electronic PPEI 3.7 GMW8773 Platform to Powertrain Electrical Interface (PPEI) Specification Brakes and Traction Control Subsystem Copyright 2006 General Motors Corporation All Rights Reserved March 2006 Originating Department: North A
2、merican Engineering Standards Page 1 of 34 1 Introduction This standard defines the Brakes and Traction Control electrical interface between Platform and Powertrain. 1.1 Applicability. The GMW8762 PPEI (Platform to Powertrain Electrical Interface) Standard Specification includes: General Information
3、, On-Board Diagnostics and Electrical Requirements and GMLAN Serial Data Signal Definitions and Framing for the following nineteen PPEI subsystems standard specifications: 1. GMW8763 Power and Ground 2. GMW8764 Four Wheel Drive/All Wheel Drive Controls 3. GMW8765 Displays and Gauges 4. GMW8766 Engin
4、e Power Management 5. GMW8767 Starter Control 6. GMW8768 Vehicle Theft Deterrent 7. GMW8769 Cruise Control 8. GMW8770 Cooling Fan Control 9. GMW8771 Air Conditioning Compressor Control 10. GMW8772 Serial Data Architecture 11. GMW8773 Brakes and Traction Control 12. GMW8774 Enhanced Evaporative Emiss
5、ions and Fuel 13. GMW8775 Exhaust After-Treatment 14. GMW8776 Suspension Control 15. GMW8777 Transmission 16. GMW8778 Generator Control 17. GMW8779 Post Collision Operation 18. GMW8780 Power Take-Off and Fast Idle Control 19. GMW8781 Vehicle Speed and Rough Road Sensing Each of the nineteen PPEI sub
6、system standard specifications contains the hardware, serial data, algorithms and calibrations for the named subsystem. The master PPEI document and all nineteen PPEI subsystem standard specifications are required to define the complete set of PPEI requirements. 2 References Note: Only the latest ap
7、proved standards are applicable unless otherwise specified. 2.1 External Standards/Specifications. None. 2.2 GM Standards/Specifications. GMW3001 GMW8771 GMW3059 GMW8772 GMW8762 GMW8774 GMW8763 GMW8775 GMW8764 GMW8776 GMW8765 GMW8777 GMW8766 GMW8778 GMW8767 GMW8779 GMW8768 GMW8780 GMW8769 GMW8781 GM
8、W8770 2.3 Additional References. None. GMW8773 GM WORLDWIDE ENGINEERING STANDARDS Copyright 2006 General Motors Corporation All Rights Reserved Page 2 of 34 March 2006 3 Subsystem Requirements 3.1 Functional Overview. The interface defined in this section shall apply to the following platform functi
9、ons. Driver application of the brake pedal Anti-Lock Brake System (ABS) Traction Control Systems Vehicle Stability Enhancement System (VSES) Driver application of the park brake Brake Boost Vacuum Sensing Brake Torque Management Brake System Speed Limiting Brake Thermal Modeling Auto Grade Braking A
10、daptive Cruise Control Braking Vehicles without ABS will support only: Driver application of the brake pedal Driver application of the park brake Brake Boost Vacuum Sensing (if required) Brake Torque Management 3.1.1 Driver Application of the Brake Pedal. A hard-wired signal, from the platform to th
11、e ECM, is required on all vehicles. This signal will indicate driver application of the brake pedal for both Brake Apply Sensor (BAS) and brake switch vehicles. It is required as a hardwired brake input for ETC and other Powertrain functions. The hardwired signal will not be active when the brake la
12、mps have been turned on by a request for automatic braking and shall be activated whenever the brake pedal is applied by the driver. There shall be no undetectable single point failure or operational mode, which shall prevent detection of driver application of the brake pedal. Serial data signals fr
13、om the platform to powertrain will also provide redundant information from the BAS or brake switches. 3.1.2 Anti-Lock Brake System. The ABS System prevents excessive wheel slip during vehicle braking by controlling brake pressure at individual wheels. The EBCM performs vehicle speed/acceleration cal
14、culation, and mini spare tire detection functions that are used as part of the ABS control, and are also sent to other vehicle systems. The requirements on data sent to other systems are documented in the PPEI Sections related to those systems. For instance, wheel rotational status and ground speed
15、requirements are found in GMW8781 Section 3 PPEI Vehicle Speed and Rough Road Sensing. All ABS data is communicated over the Serial Data Link. 3.1.3 Traction Control Systems. Traction Control Systems may consist of the Enhanced Traction System (ETS) or the Full Function Traction Control System. The
16、TCS acronym generally is used to denote the Full Function Traction Control System. 3.1.3.1 Full Function Traction Control System (TCS). The TCS is a distributed system that uses both Platform and Powertrain electronics to control brake pressure of the driven wheels, control engine torque, and may al
17、so control transmission gear ratio. TCS is a system that helps maintain vehicle control and stability on slippery surfaces. Under conditions where the driven wheels are determined to be excessively spinning, the traction controller will apply brake pressure to the driven wheels to reduce the level o
18、f spin. At the same time, the traction controller will request powertrain to reduce torque via engine torque or transmission gear ratio control, preventing brake fade and excessive brake wear. The TCS interface uses only serial data signals. (Refer to Section 3.3.1 Serial Data Link.) Cruise Control
19、shall be disengaged when traction control is active for more than a calibratable time. 3.1.3.2 Enhanced Traction System (ETS). The ETS is a distributed system that uses both Platform and Powertrain electronics to control engine torque and may also control transmission gear ratio. ETS, like TCS, is a
20、 system that prevents excessive spinning of the driven wheels. Unlike TCS, ETS does not control brake pressure at the driven wheels. It relies only on powertrain torque control to control excessive wheel spin. The ETS interface uses only serial data signals. (Refer to Section 3.3.1 Serial Data Link.
21、) Cruise Control shall be disengaged when traction control is active for more than a calibratable time. GM WORLDWIDE ENGINEERING STANDARD GMW8773 Copyright 2006 General Motors Corporation All Rights Reserved March 2006 Page 3 of 34 3.1.4 Vehicle Stability Enhancement System (VSES). The VSES function
22、 is vehicle closed-loop yaw control that requires Brake and Powertrain system assistance. The drivers intended vehicle path and the actual vehicle path are observed through various vehicle sensors (steering wheel position, yaw rate, lateral acceleration, etc.). If corrections in the vehicle path are
23、 required, Brake Control (in the form of active brake pressure applied to one or more wheels) and/or Powertrain torque reduction is initiated. The VSES interface uses only serial data messages. Refer to Section 3.3.1 Serial Data Link. When the VSES intervention occurs for more than a calibratable ti
24、me, cruise control shall be disengaged. Powertrain also uses the VSES sensor information for other non-related functions. Full Function TCS is required on the vehicle for the VSES function. 3.1.5 Driver Application of the Park Brake. The platform shall send a serial data signals indicating status of
25、 the park brake. This is used by some AWD systems, as well as the ETC subsystem. 3.1.6 Brake Boost Vacuum. 3.1.6.1 Brake Boost Vacuum Determination The Powertrain electronics shall support two methods for determining Brake Boost Vacuum: direct sensor measurement and indirect estimation. The Powertra
26、in electronics shall provide a calibration option to select either method: K_VacSensingConfig= “Model”, “Sensor”, or “NoVacSensor” When No VacSensor, Vacuum Pressure = 0 kPa 3.1.6.2 Brake Boost Vacuum Sensing Powertrain uses the platform provided vacuum sensor and calibrations to determine brake boo
27、st vacuum. When vacuum rises above the K_MinVacuumLevel threshold, cylinder deactivation is turned off to provide more vacuum boost for braking. Vout = Vcc (K_Vacuum_Sensor_k1 * P + K_Vacuum_Sensor_k2), where P is input vacuum pressure K_Vacuum_Sensor_k1 is the gain of the sensor K_Vacuum_Sensor_k2
28、is the offset of the sensor The full-scale (max voltage) value of the sensor is K_Vacuum_Sensor_P. Refer to GMW8762 Section 3 for additional requirements. 3.1.6.3 Brake Boost Vacuum Estimation The Brake Boost Vacuum Estimation (BBVE) function utilizes vehicle speed, manifold absolute pressure and at
29、mospheric pressure to calculate an estimated brake boost vacuum. The resulting BBVE value is compared to a predetermine threshold to determine when the engine Displacement on Demand (DoD) function should be disabled (revert to all cylinder mode) to maintain adequate brake boost vacuum for vehicle br
30、aking. Some Powertrain systems (e.g. cylinder deactivation, CVT, Coordinated Torque Control, etc.) may adjust engine controls for increased fuel economy and may cause a reduction in brake booster vacuum. These systems require a vacuum pressure sensor in the brake booster on vehicles that use vacuum
31、for brake assist. 3.1.7 Brake Torque Management. Some Platform systems require an additional serial data signal for brake torque management. These systems limit engine torque to a value that the braking system is able to absorb under moderate brake apply conditions. Vehicles equipped with brake torq
32、ue management and using discrete brake switches require a switch indicating that moderate brake pedal travel has been achieved. This switch allows the platform electronics to produce a serial data signal indicating that moderate brake pedal travel has been achieved for use in brake torque management
33、. On a BAS vehicle, the platform electronics uses the BAS input to generate the serial data signal indicating that moderate brake pedal travel has been achieved for use in brake torque management. 3.1.8 Brake System Speed Limiting. Some brake systems require the ability to limit top vehicle speed in
34、 the event of certain types of brake system faults. The EBCM will send a signal to the Platform Gateway, which will arbitrate speed limits of various Platform modules. The Gateway determines the allowable top speed limit dynamically, and transmits this value to the powertrain via the GMLAN signal Ve
35、hicle Top Speed Limit Request. 3.1.9 Brake Thermal Modeling. A Brake Thermal Model may be implemented by some platforms. This model will estimate brake temperature from a combination of vehicle speed, GMW8773 GM WORLDWIDE ENGINEERING STANDARDS Copyright 2006 General Motors Corporation All Rights Res
36、erved Page 4 of 34 March 2006 vehicle deceleration, engine torque, gear ratio, ambient temperature (and brake pedal position, if available). The estimated brake temperature will be transmitted optionally to the powertrain via the GMLAN signal Brake Temperature. The brake temperature can be used as p
37、art of an Auto Grade Braking algorithm, or to warn the driver, via a telltale or signal, of reduced brake function. 3.1.10 Auto Grade Braking. Some transmissions incorporate an Auto Grade Braking algorithm based on vehicle speed, deceleration, gear ratio, engine torque, and brake application. Using
38、additional parameters such as brake pedal position (intended vehicle deceleration) and predicted brake temperature the transmission can achieve a more robust level of operation. These additional parameters will be sent by the platform to powertrain over serial data when available, via the GMLAN sign
39、als Brake Temperature and Chassis Braking Load. 3.1.11 Adaptive Cruise Control Braking. When Adaptive Cruise Control (ACC) is present on a vehicle, the ECM and brake controller will receive vehicle deceleration requests from the ACC controller. The brake controller will provide brake pressure when i
40、t determines that the ECM is not capable of providing the requested deceleration. Reference GMW8769 Section 3 PPEI Cruise Control Functional Requirements and GMW8773 Section 4 PPEI Brakes and Traction Control Algorithm Requirements, for further information on adaptive cruise control braking function
41、ality. 3.2 Hardware Overview. The electrical interface between the Platform Electronics and the Powertrain Electronics for the Brakes and Traction Control System consists of the serial data link and a single discrete line indicating driver application of the brake pedal. An optional sensor using a t
42、hree wire interface to indicate the vacuum level available at the brake booster is required for vehicles equipped with cylinder deactivation, coordinated torque control or CVT used in conjunction with vacuum assisted brakes. On a BAS vehicle, the platform electronics generates both the Brake Pedal A
43、pply discrete and serial data Brake Pedal Initial Travel Achieved signal. On a Brake Switch vehicle (requires two switches) the normally closed switch is used to generate the serial data message, and the normally open switch shall be used to generate the Brake Pedal Apply (BPA) discrete. Vehicles us
44、ing discrete brake switches may also have an optional switch indicating that moderate brake pedal travel has been achieved. 3.2.1 Block Diagram. The following block diagrams (Figure 1 and Figure 2) depict possible mechanizations for the ABS, ETS, TCS and VSES. The electrical interface between Powert
45、rain and Platform is the only standard defined. -,-,- GM WORLDWIDE ENGINEERING STANDARD GMW8773 Copyright 2006 General Motors Corporation All Rights Reserved March 2006 Page 5 of 34 3.2.1.1 Block Diagram - Brake Switch Mechanization N/O Battery or Run/Crank (BLS) Brake Lamp Switch Run/Crank N/C Redu
46、ndant Brake Switch Run/Crank N/C Moderate Travel Brake Switch (Optional) 3 Platform Electronics 2 Brake Lamp Output Brake Pedal Apply 2 Powertrain Electronics Powertrain Platform Brake Boost Vacuum Pressure Sensor +5 V Supply Brake Boost Vacuum Pressure Output Brake Boost Vacuum Pressure Sensor Retu
47、rn Brake Boost Vacuum Pressure Sensor Notes: 1. On non-adaptive cruise vehicles either the Brake Lamp Output or Brake Lamp Switch may feed the CHMSL, brake lamp relay, filament, or hazard/flasher module. The Brake Pedal Apply line shall have a 750 Ohm load or less on the platform side. 2. On Adaptiv
48、e Cruise Control vehicles, separate Brake Lamp and Brake Pedal Apply output are required. Only the Brake Lamp output shall feed the CHMSL, brake lamp relay, filament, or hazard/flasher module. The Brake Pedal Apply line shall have a 750 Ohm load or less on the platform side. 3. Specific mechanizatio
49、n of redundant and moderate travel switches is determined by platform. 1 1 Serial Data Link 3 Figure 1: Brake Switch Mechanization Block Diagram -,-,- GMW8773 GM WORLDWIDE ENGINEERING STANDARDS Copyright 2006 General Motors Corporation All Rights Reserved Page 6 of 34 March 2006 3.2.1.2 Block Diagram - Brake Apply Sensor Mechanization. 3119-024(08/02) Brake Lamp Output 1 2 Serial Data Link Notes: 1. The Brake Lamp Output feeds the CHMSL and also conn
链接地址:https://www.31doc.com/p-3769596.html