Transmission with electronic range selector and pull out of park control logic

Patent metadata

Field	Value
Publication number	US-9399454-B2
Application number	US-201414549593-A
Country	US
Kind code	B2
Filing date	Nov 21, 2014
Priority date	Nov 21, 2014
Publication date	Jul 26, 2016
Grant date	Jul 26, 2016

Abstract

A vehicle includes a transmission, and an Electronic Transmission Range Selection (ETRS) system. The transmission has a plurality of clutches, a park pawl, and a park sensor. The ETRS system has a controller and an electronic range selector device. The controller is programmed to detect a delay in pull out of the park pawl from a park position and to control an action of the vehicle in response to the delay by receiving an electronic range request signal to shift from a park operating range to another operating range; receiving a park pawl position signal from the park sensor; determining if pull out of the park pawl from the park position has not occurred by a predetermined time; and increasing one of a line pressure, a clutch pressure, and an idle speed if pull out of the park pawl from the park position has not occurred by the predetermined time.

First claim

The invention claimed is:

1. A vehicle comprising:
an engine having an idle speed;
a transmission connected to the engine and having:
a hydraulic pressure source for supplying a hydraulic fluid at a line pressure;
a plurality of clutches, each having a respective clutch pressure;
a shift valve that is in fluid communication with the hydraulic pressure source and the plurality of clutches, wherein the shift valve is operable to shift the transmission to a requested operating range via the plurality of clutches;
a park pawl that is pulled out of a park position to shift the transmission out of a park operating range via one or more of the clutches when the transmission is requested to shift from the park operating range to another operating range; and
a park sensor configured to determine if the park pawl is pulled out of the park position; and

an electronic transmission range selection (ETRS) system having a controller and an electronic range selector device, wherein the electronic range selector device is operable to transmit an electronic range request signal to the controller to request a shift of the transmission to the requested operating range;
wherein the controller is programmed to detect a delay in pull out of the park pawl from the park position when the transmission is requested to shift from the park operating range to another operating range, and to control an action of the vehicle in response to the delay by:
receiving the electronic range request signal to shift from the park operating range to another operating range from the electronic range selector device;
receiving a park pawl position signal from the park sensor indicative of the park pawl being pulled out of the park position;
determining if pull out of the park pawl from the park position has not occurred by a predetermined time after the range request signal has been received; and
increasing one of the line pressure, the clutch pressures, and the idle speed if pull out of the park pawl from the park position has not occurred by the predetermined time.

2. The vehicle of claim 1 , further comprising a grade sensor configured to detect an upgrade and a downgrade relative to the vehicle direction;
wherein the controller is programmed to receive a grade signal from the grade sensor, to determine if the upgrade exceeds a predetermined upgrade and the downgrade exceeds a predetermined downgrade, and to increase one of the line pressure, the clutch pressures, and the idle speed when one of the predetermined upgrade and the predetermined downgrade is detected and the electronic range request signal to shift from the park operating range to another operating range is received from the electronic range selector device.

3. The vehicle of claim 2 , further comprising a brake having a brake sensor for determining if the brake is applied;
wherein the controller is programmed to receive a brake application signal from the brake sensor and to increase one of the line pressure, the clutch pressures, and the idle speed and to apply a drive operating range when the electronic range request signal to shift from the park operating range to the drive operating range is received from the electronic range selector device, the upgrade exceeds the predetermined upgrade, and the brake is applied; and
wherein the controller is programmed to increase one of the line pressure, the clutch pressures, and the idle speed and to apply a reverse operating range when the electronic range request signal to shift from the park operating range to the reverse operating range is received from the electronic range selector device, the downgrade exceeds the predetermined downgrade, and the brake is applied.

4. The vehicle of claim 3 , further comprising an indicator device;
wherein the controller is programmed to return the transmission to the park operating range and to transmit an indicator signal to the indicator device if pull out of the park pawl from the park position has not occurred by the predetermined time after increasing one of the line pressure, the clutch pressures, and the idle speed and applying one of the drive operating range and the reverse operating range.

5. The vehicle of claim 1 , wherein the controller is programmed to increase one of the line pressure, the clutch pressures, and the idle speed when the electronic range request signal to shift from the park operating range to another operating range is received from the electronic range selector device and pull out of the park pawl from the park position did not occur by the predetermined time in a previous shift from the park operating range to another operating range.

6. The vehicle of claim 1 , wherein the controller is programmed to return the transmission to the park operating range if pull out of the park pawl from the park position has not occurred by the predetermined time after increasing one of the line pressure, the clutch pressures, and the idle speed.

7. The vehicle of claim 6 , further comprising an indicator device;
wherein the controller is programmed to transmit an indicator signal to the indicator device if pull out of the park pawl from the park position has not occurred by the predetermined time after increasing one of the line pressure, the clutch pressures, and the idle speed.

8. A system for use in a vehicle having an engine and a transmission, the system comprising:
a hydraulic pressure source for supplying a hydraulic fluid at a line pressure;
a plurality of clutches, each having a respective clutch pressure;
a shift valve that is in fluid communication with the hydraulic pressure source and the plurality of clutches, wherein the shift valve is operable to shift the transmission to a requested operating range via the plurality of clutches;
a park pawl that is pulled out of a park position to shift the transmission out of a park operating range via one or more of the clutches when the transmission is requested to shift from the park operating range to another operating range;
a park sensor configured to determine if the park pawl is pulled out of the park position; and
an electronic transmission range selection (ETRS) system having a controller and an electronic range selector device, wherein the electronic range selector device is operable to transmit an electronic range request signal to the controller to request the shift of the transmission to the requested operating range; and
wherein the controller is in communication with the electronic transmission range selection system and the park sensor and is programmed to:
receive the electronic range request signal to shift from the park operating range to another operating range from the electronic range selector device;
receive a park pawl position signal from the park sensor indicative of the park pawl being pulled out of the park position;
determine if pull out of the park pawl from the park position has not occurred by a predetermined time after the range request signal has been received; and
increase one of the line pressure, the clutch pressures, and an idle speed of the engine if pull out of the park pawl from the park position has not occurred by the predetermined time.

9. The system of claim 8 , further comprising a grade sensor configured to detect an upgrade and a downgrade relative to the vehicle direction;
wherein the controller is programmed to:
receive a grade signal from the grade sensor;
determine if the upgrade exceeds a predetermined upgrade and the downgrade exceeds a predetermined downgrade; and
increase one of the line pressure, the clutch pressures, and the idle speed when one of the predetermined upgrade and the predetermined downgrade is detected and the electronic range request signal to shift from t

Assignees

• Gm Global Tech Operations Llc

Inventors

• Somerville James Robert
• Gunderson Joel H

Classifications

• B60W10/08

  including control of electric propulsion units, e.g. motors or generators · CPC title

• F16H2061/1224

  Adapting to failures or work around with other constraints, e.g. circumvention by avoiding use of failed parts · CPC title

• B60W2710/0644

  Engine speed · CPC title

• B60W2552/15

  Road slope, i.e. the inclination of a road segment in the longitudinal direction · CPC title

• B60W30/19 Primary

  Improvement of gear change, e.g. by synchronisation or smoothing gear shift · CPC title