AUTOMATIC TRANSMISSION

• US 20090198423A1
• Filed: 01/30/2009
• Published: 08/06/2009
• Est. Priority Date: 02/01/2008
• Status: Abandoned Application

• Current Assignee: GM Global Technology Operations LLC (General Motors Company)
• Original Assignee: GM Global Technology Operations Incorporated (General Motors Company)
• Inventors: HOLTZ, Vincent, TISSOT, Pascal
• Application Number:
  US12/363,595
• Publication Number:
  US 20090198423A1
• Time in Patent Office: Days
• US Class Current: 701/55
• CPC Class Codes: F16H 2061/0496 for low engine torque, e.g. during coasting, sailing or engine braking
• CPC Class Codes: F16H 2061/1208 with diagnostic check cycles; Monitoring of failures
• CPC Class Codes: F16H 2061/1268 Electric parts of the controller, e.g. a defect solenoid, wiring or microprocessor
• CPC Class Codes: F16H 2306/42 Changing the input torque to the transmission
• CPC Class Codes: F16H 61/0437 by using electrical signals F16H61/0403 and F16H61/061 take precedence
• CPC Class Codes: F16H 61/12 Detecting malfunction or potential malfunction, e.g. fail safe in control of hydrostatic gearing F16H61/4192; Circumventing or fixing failures
• CPC Class Codes: F16H 63/502 for smoothing gear shifts

Abstract

An automatic transmission is provided with an engine control module and a process for controlling an automatic transmission. In order to assure secure positive torque requests during lift foot upshifts, an automatic transmission is described which includes, but is not limited to a transmission control module with means for sending an upshift positive torque request on CAN and means for an upshift positive torque supervision preventing the transmission from requesting unexpected positive torque. The means for an upshift positive torque supervision are designed to differentiate upshift conditions under which the positive torque is not expected to occur from shift conditions where it is expected to occur. They allow secure positive torque requests during lift foot upshifts.

Claims

1. An automatic transmission with an engine control module, comprising:

a means for sending an upshift positive torque request on CAN; and

a means for an upshift positive torque supervision preventing the automatic transmission from requesting unexpected positive torque.

2. The automatic transmission of claim 1, wherein the means for the upshift positive torque supervision is designed to differentiate upshift conditions under which a positive torque is not expected to occur from shift conditions that are expected to occur.

3. The automatic transmission of claim 2, wherein a positive torque request is supervised by at least one of maximum upshift time, below low speed upshift, and above low speed upshift.

4. The automatic transmission of claim 2, wherein a positive torque request is supervised by maximum upshift time, below low speed upshift, and above low speed upshift.

5. A method for controlling an automatic transmission, comprising the steps of:

sending an upshift positive torque request on CAN;

supervising an upshift positive torque; and

preventing the automatic transmission from requesting an unexpected positive torque based at least in part on the supervising of the upshift positive torque.

6. The method according to claim 5, wherein the upshift positive torque is only allowed if the supervising indicates that a positive torque is not unexpected.