Method and apparatus for controlling a vehicle in a coasting mode

Patent metadata

Field	Value
Publication number	US-10960883-B2
Application number	US-201816133022-A
Country	US
Kind code	B2
Filing date	Sep 17, 2018
Priority date	Sep 17, 2018
Publication date	Mar 30, 2021
Grant date	Mar 30, 2021

Abstract

A powertrain system for a vehicle is described, and includes an internal combustion engine that is selectively coupled to a driveline. The engine is configured to operate in a coasting mode, wherein the coasting mode includes operating the powertrain system with the engine in an OFF state and decoupled from the driveline. Devices are configured to monitor an output torque request, vehicle speed, and vehicle operating conditions. An executable instruction set monitors the vehicle speed and the output torque request. The engine is controlled to operate in the coasting mode when the output torque request is within the predetermined torque region and the vehicle speed is greater than a minimum speed threshold. The engine is controlled to discontinue operating in the coasting mode in response to the output torque request being outside the torque region of the vehicle speed being less than a minimum speed threshold.

First claim

What is claimed is:

1. A powertrain system for a vehicle, comprising:
an internal combustion engine selectively coupled to a driveline, wherein the internal combustion engine is configured to operate in a coasting mode, wherein the coasting mode includes operating the powertrain system with the internal combustion engine in an OFF state;
a plurality of devices disposed to monitor vehicle operating conditions;
a cruise control system configured to control the powertrain system to generate torque to maintain vehicle speed at a target speed, wherein the target speed includes a speed offset and an adjusted speed offset associated with the coasting mode, wherein the adjusted speed offset is greater than the speed offset; and
a controller, operatively connected to the internal combustion engine and in communication with the plurality of devices disposed to monitor vehicle operating conditions;
the controller including an instruction set, the instruction set executable to:
determine vehicle speed,
determine an output torque request,
activate the cruise control system;
decouple the internal combustion engine from the driveline,
control the internal combustion engine to operate in the coasting mode when the output torque request is within a predetermined torque region and the vehicle speed is greater than a minimum speed threshold,
control the internal combustion engine to exit the coasting mode when the vehicle speed exceeds the target speed combined with the adjusted speed offset; and
control the internal combustion engine to discontinue operating in the coasting mode in response to one of the output torque request being outside the predetermined torque region or the vehicle speed being less than the minimum speed threshold.

2. The powertrain system of claim 1 , comprising the internal combustion engine being selectively coupled to the driveline via activation of a disconnect clutch, wherein the coasting mode includes the internal combustion engine being controlled in the OFF state and decoupled from the driveline via the disconnect clutch.

3. The powertrain system of claim 1 , wherein the output torque request being within the predetermined torque region comprises the output torque request being within a region of +5% and −5% of a maximum torque output of the internal combustion engine.

4. The powertrain system of claim 1 , further comprising the instruction set being executable to control the internal combustion engine to discontinue operating in the coasting mode in response to an operator request for braking.

5. The powertrain system of claim 1 , further comprising the instruction set being executable to control the internal combustion engine to discontinue operating in the coasting mode in response to an operator request for acceleration.

6. The powertrain system of claim 1 , wherein the instruction set is executable to:
determine secondary enablement criteria based upon inputs from the plurality of devices disposed to monitor the vehicle operating conditions,
control the internal combustion engine to operate in the coasting mode when the output torque request is within the predetermined torque region, the vehicle speed is greater than the minimum speed threshold, and the secondary enablement criteria are met, and
control the internal combustion engine to discontinue the operating in the coasting mode in response to the secondary enablement criteria no longer being met.

7. The powertrain system of claim 6 , wherein the plurality of devices disposed to monitor vehicle operating conditions comprises an engine coolant temperature sensor, wherein the secondary enablement criteria includes engine coolant temperature, and wherein the instruction set is executable to control the internal combustion engine to discontinue the operating in the coasting mode when the engine coolant temperature is less than a minimum temperature, wherein the minimum temperature is associated with internal combustion engine operation to achieve a minimum exhaust temperature for exhaust purification.

8. The powertrain system of claim 6 , wherein the plurality of devices disposed to monitor vehicle operating conditions comprises an engine coolant temperature sensor, wherein the secondary enablement criteria includes engine coolant temperature, and wherein the instruction set is executable to control the internal combustion engine to discontinue the operating in the coasting mode when the engine coolant temperature is greater than a maximum temperature.

9. The powertrain system of claim 6 , wherein the plurality of devices disposed to monitor vehicle operating conditions comprises an ambient temperature sensor, wherein the secondary enablement criteria includes ambient temperature, and wherein the instruction set is executable to control the internal combustion engine to discontinue the operating in the coasting mode when the ambient temperature is less than a minimum temperature.

10. The powertrain system of claim 6 , wherein the plurality of devices disposed to monitor vehicle operating conditions comprises an ambient temperature sensor, wherein the secondary enablement criteria includes ambient temperature, and wherein the instruction set is executable to control the internal combustion engine to discontinue the operating in the coasting mode when the ambient temperature is greater than a maximum temperature.

11. The powertrain system of claim 6 , further comprising an electric machine being coupled to the internal combustion engine; wherein the plurality of devices disposed to monitor vehicle operating conditions comprises a device disposed to monitor a battery that is electrically connected to the electric machine, wherein the secondary enablement criteria includes battery state-of-charge (SOC), and wherein the instruction set is executable to control the internal combustion engine to discontinue the operating in the coasting mode when the battery SOC is less than a minimum SOC.

12. The powertrain system of claim 6 , wherein the plurality of devices disposed to monitor vehicle operating conditions comprises a cabin environmental control switch that is configured to control operation of a heating-ventilation-air-condition (HVAC) system, wherein the secondary enablement criteria includes activation of the HVAC system, and wherein the instruction set is executable to control the internal combustion engine to discontinue the operating in the coasting mode when the HVAC system is activated.

13. A method for controlling a powertrain system for a vehicle, the powertrain system including an internal combustion engine coupled to a driveline via a disconnect clutch, and the vehicle including a cruise control system configured to control the powertrain system to generate torque to maintain vehicle speed at a target speed, wherein the target speed includes a speed offset and an adjusted speed offset associated with the coasting mode, wherein the adjusted speed offset is greater than the speed offset; wherein the internal combustion engine is configured to operate in a coasting mode, wherein the coasting mode includes operating the powertrain system with the internal combustion engine in an OFF state, the method comprising:
monitoring vehicle speed;
monitoring an output torque request;
activating the cruise control system;
monitoring a plurality of secondary enablement criteria;
controlling the internal combustion engine to operate in the coasting mode when the output torque request is within a predetermined torque region, the vehicle speed is greater than a minimum speed threshold, and the secondary enablement criteria are met;
controlling the internal combustion engine to exit the coas

Assignees

• Gm Global Tech Operations Llc

Inventors

• Tamai Goro
• Bhattarai Birendra P
• Nicholson Daniel E

Classifications

• Y02T10/60

  Other road transportation technologies with climate change mitigation effect · CPC title

• B60W2510/244

  Charge state · CPC title

• B60W2555/20

  Ambient conditions, e.g. wind or rain · CPC title

• B60W40/00

  Estimation or calculation of {non-directly measurable} driving parameters for road vehicle drive control systems not related to the control of a particular sub unit, {e.g. by using mathematical models} · CPC title

• B60W2540/10

  Accelerator pedal position · CPC title