Methods and systems for efficient engine torque control

• US 10,243,494 B2
• Filed: 02/12/2018
• Issued: 03/26/2019
• Est. Priority Date: 05/01/2015
• Status: Expired due to Fees

• Current Assignee: Ford Global Technologies, LLC (Ford Motor Company)
• Original Assignee: Ford Global Technologies, LLC (Ford Motor Company)
• Inventors: Pallett, Tobias John, Teslak, Christopher John, Zhao, Yanan, Crisp, Nicholas Dashwood, Johri, Rajit, Doering, Jeffrey Allen
• Primary Examiner(s): Vilakazi, Sizo B
• Application Number:
  US15/894,599
• Publication Number:
  US 20180167007A1
• Time in Patent Office: 407 Days
• Field of Search: 123198 DB, 123198 DC, 123198 F
• CPC Class Codes: F02D 2250/18 Control of the engine output torque
• CPC Class Codes: F02D 2250/22 by keeping a torque reserve, i.e. with temporarily reduced drive train or engine efficiency
• CPC Class Codes: F02D 2250/24 by using an external load, e.g. a generator
• CPC Class Codes: F02D 37/02 one of the functions being ignition
• CPC Class Codes: F02D 41/0002 Controlling intake air
• CPC Class Codes: F02D 41/107 and deceleration
• CPC Class Codes: F02D 41/123 the fuel injection being cut-off
• CPC Class Codes: F02D 41/126 transitional corrections at the end of the cut-off period
• CPC Class Codes: F02P 5/045 combined with electronic control of other engine functions, e.g. fuel injection in general F02D37/02
• CPC Class Codes: F02P 5/1504 with particular means during a transient phase, e.g. acceleration, deceleration, gear change during starting F02P5/1506
• CPC Class Codes: H02P 9/008 wherein the generator is controlled by the requirements of the prime mover
• CPC Class Codes: Y02T 10/40 Engine management systems

Abstract

Method and systems are provided for adjusting an engine torque in response to changes in a desired engine torque. In one example, a method may comprise responsive to increasing desired engine torques, monotonically decreasing an alternator torque to a first level from a second level when not injecting fuel to engine cylinders, and stepping up the alternator torque from the first level to the second level while initiating engine combustion, and then monotonically decreasing the alternator torque from the second level to the first level in response to the alternator torque reaching the first level. In this way, a method may comprise adjusting a load exerted on an engine by an alternator mechanically coupled to said engine during both cylinder combustion, and during non-fueling conditions.

Claims

1. A vehicle system comprising:

an engine with one or more cylinders;

an alternator mechanically coupled to the engine;

a first battery electrically coupled to a starting system for starting the vehicle system and turning on the engine, and selectively electrically coupled to one or more of the alternator and various electrical loads;

a second battery electrically coupled to the alternator and the electrical loads;

a voltage regulator configured to maintain a voltage and/or current supplied to a field coil of the alternator to a set point; and

a controller with computer readable instructions for adjusting the voltage and/or current supplied to the field coil between a first level and a second level based on engine operating conditions, where the adjusting comprises;

when not injecting fuel to the one or more engine cylinders, monotonically decreasing the voltage and/or current supplied to the field coil with increasing engine torque demand, and in response to a desired engine torque reaching a first threshold, stepping up the current and/or voltage supplied to the field coil from the first level to the second level;

when injecting fuel to the one or more engine cylinders, monotonically decreasing an alternator torque with increasing engine torque demand from the first threshold to a second threshold; and

maintaining the current and/or voltage supplied to the field coil at the first level in response to the engine torque demand increasing above the second threshold.

2. The system of claim 1, wherein the instructions further include instructions to monotonically decrease alternator torque to a first torque from a second torque as the desired engine torque increases, and during cylinder combustion, maintain a position of a throttle valve and monotonically decrease alternator torque to the first torque from the second torque as the desired engine torque increases.

3. The system of claim 2, wherein the instructions further include instructions to retard spark timing from a desired spark timing during cylinder combustion, when the alternator torque is at the second level, and engine torque is greater than desired.

4. A vehicle system comprising:

an engine with one or more cylinders;

an alternator mechanically coupled to the engine;

a first battery electrically coupled to a starting system for starting the vehicle system and turning on the engine, and selectively electrically coupled to one or more of the alternator and various electrical loads;

a second battery electrically coupled to the alternator and the electrical loads;

a voltage regulator configured to maintain a voltage and/or current supplied to a field coil of the alternator to a set point; and

a controller with computer readable instructions for;

during deceleration fuel shut-off (DFSO), when a throttle valve is in a first position and fuel is not injected to the one or more engine cylinders, monotonically decreasing alternator torque to a first torque from a second torque as desired engine torque increases up to a first level, and during cylinder combustion, maintaining position of the throttle valve in a second position and monotonically decreasing alternator torque to the first torque from the second torque as the desired engine torque increases from the first level to a second level.

5. The system of claim 4, wherein the instructions further include instructions to adjust a position of the throttle valve between the second position and a third position as the desired engine torque increases above the second level.

6. The system of claim 4, wherein the instructions further include instructions to retard spark timing from a desired spark timing during cylinder combustion, when an alternator torque is at the second level, and engine torque is greater than desired.