# US 8,751,078 B2 · Off-going clutch control

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- Number: US 8,751,078 B2
- Document ID: US8751078B2
- Status: Granted
- Kind: B2
- Application number: 13/087,419
- Filed: 2011-04-15
- Published: 2012-10-18
- Granted: 2014-06-10
- Earliest claimed: 2011-04-15
- Assignees: GM Global Technology Operations LLC
- Applicants: Lawrence A. Kaminsky; Jy-Jen F. Sah
- Inventors: Lawrence A. Kaminsky; Jy-Jen F. Sah
- Web page: https://patentgrep.com/patent/US8751078B2

## CPC

- B60W 20/00: Control systems specially adapted for hybrid vehicles {(hybrid vehicle design, B60K6/00; electric vehicles B60L)}
- B60K 6/445: Differential gearing distribution type
- B60W 10/02: including control of driveline clutches
- B60W 10/115: with planetary gears
- B60W 50/0098: {Details of control systems ensuring comfort, safety or stability not otherwise provided for}
- B60W 2050/0096: {Control during transition between modes}
- B60W 2710/025: Clutch slip, i.e. difference between input and output speeds
- F16D 2500/1066: Hybrid
- F16D 2500/50858: Selecting a Mode of operation
- F16D 2500/70426: Clutch slip
- Y02T 10/62: Hybrid vehicles
- B60W: CONJOINT CONTROL OF VEHICLE SUB-UNITS OF DIFFERENT TYPE OR DIFFERENT FUNCTION; CONTROL SYSTEMS SPECIALLY ADAPTED FOR HYBRID VEHICLES; ROAD VEHICLE DRIVE CONTROL SYSTEMS FOR PURPOSES NOT RELATED TO THE CONTROL OF A PARTICULAR SUB-UNIT
- B60K: ARRANGEMENT OR MOUNTING OF PROPULSION UNITS OR OF TRANSMISSIONS IN VEHICLES; ARRANGEMENT OR MOUNTING OF PLURAL DIVERSE PRIME-MOVERS IN VEHICLES; AUXILIARY DRIVES FOR VEHICLES; INSTRUMENTATION OR DASHBOARDS FOR VEHICLES; ARRANGEMENTS IN CONNECTION WITH COOLING, AIR INTAKE, GAS EXHAUST OR FUEL SUPPLY OF PROPULSION UNITS IN VEHICLES
- F16D: COUPLINGS FOR TRANSMITTING ROTATION; CLUTCHES; BRAKES
- Y02T: CLIMATE CHANGE MITIGATION TECHNOLOGIES RELATED TO TRANSPORTATION

## Abstract

A vehicle includes an engine, a motor, and a gearbox. A clutch is configured to engage to transfer a reactive torque to at least one of the engine, the motor, and the gearbox. The clutch is configured to disengage during a transition from a present operating mode to a target operating mode. A controller is configured to determine an expected slip direction of the clutch, define a non-zero value based at least in part on the expected slip direction, and command the reactive torque to the non-zero value to control the clutch to induce slip during the transition from the present operating mode to the target operating mode.

## Claims

### Claim 1

A vehicle comprising:
an engine configured to generate an engine torque;
a motor configured to generate a motor torque;
a gearbox configured to receive at least one of the engine torque and the motor torque;
a clutch configured to engage to transfer a reactive torque to at least one of the engine, the motor, and the gearbox, and wherein the clutch is configured to disengage during a transition from a present operating mode to a target operating mode; and
a controller configured to determine an expected slip direction of the clutch, define a non-zero value based at least in part on the expected slip direction, and command the reactive torque to the non-zero value to control the clutch to induce slip during the transition from the present operating mode to the target operating mode.

### Claim 2 (depends on 1)

A vehicle as set forth in claim 1, wherein the controller is configured to determine the expected slip direction based on an expected rotation of the clutch in either a first direction or a second direction.

### Claim 3 (depends on 2)

A vehicle as set forth in claim 2, wherein the controller is configured to define the non-zero value as a positive number if the expected slip direction is the first direction and define the non-zero value as a negative number if the expected slip direction is the second direction.

### Claim 4 (depends on 1)

A vehicle as set forth in claim 1, wherein the non-zero value is based at least in part on a calibration magnitude.

### Claim 5 (depends on 1)

A vehicle as set forth in claim 1, wherein the reactive torque is bound by a torque constraint and wherein the controller is configured to converge the torque constraint toward the non-zero value during the transition from the present operating mode to the target operating mode.

### Claim 6 (depends on 1)

A vehicle as set forth in claim 1, wherein the controller is configured to maintain the engagement of the clutch at least until the reactive torque of the clutch is substantially equal to the non-zero value.

### Claim 7 (depends on 6)

A vehicle as set forth in claim 6, wherein the controller is configured to disengage the clutch when the reactive torque is substantially equal to the non-zero value.

### Claim 8 (depends on 7)

A vehicle as set forth in claim 7, wherein the controller is configured to command a capacity of the clutch to substantially zero to disengage the clutch.

### Claim 9 (depends on 8)

A vehicle as set forth in claim 8, wherein the controller is configured to determine whether the clutch has disengaged after commanding the capacity of the clutch to substantially zero.

### Claim 10 (depends on 1)

A vehicle as set forth in claim 1, wherein the controller is configured to determine an expected slip speed and derive the expected slip direction based at least in part on the expected slip speed.