Torque compensation for air/fuel switching

Patent metadata

Field	Value
Publication number	US-12448931-B2
Application number	US-202318171417-A
Country	US
Kind code	B2
Filing date	Feb 20, 2023
Priority date	Feb 20, 2023
Publication date	Oct 21, 2025
Grant date	Oct 21, 2025

Abstract

A vehicle includes one or more processors configured to select an air/fuel ratio for the engine that is different from the stoichiometric air/fuel ratio. The one or more processors are further configured to select a torque request for the engine, determine a load request for the engine based on at least the torque request and the selected air/fuel ratio, and determine an output to a throttle actuator based on the load request for the engine.

First claim

What is claimed is:

1. A vehicle comprising:
one or more processors disposed within the vehicle and configured to:
select an air/fuel ratio for an engine of the vehicle, wherein the selected air/fuel ratio is different from a stoichiometric air/fuel ratio;
select a torque request for the engine;
determine a load request for the engine based on at least the torque request and the selected air/fuel ratio; and

determine a first output to a throttle actuator based on the load request for the engine,
wherein the one or more processors are further configured to:
if the selected air/fuel ratio exceeds a threshold maximum, determine the load request for the engine based on at least the torque request and the threshold maximum; and
if the selected air/fuel ratio is less than a threshold minimum, determine the load request for the engine based on at least the torque request and the threshold minimum.

2. The vehicle of claim 1 , wherein the one or more processors are further configured to determine a second output to a spark actuator based on the load request for the engine.

3. The vehicle of claim 1 , wherein the one or more processors are further configured to determine a third output to a variable valve timing (VVT) actuator based on the load request for the engine.

4. The vehicle of claim 1 , wherein selecting the air/fuel ratio is based at least in part on a sensor reading from an air/fuel sensor located downstream of a catalytic converter in an exhaust system of the vehicle.

5. The vehicle of claim 4 , wherein the air/fuel ratio is selected to improve performance of the catalytic converter by affecting a ratio of oxygen and hydrocarbons stored within a catalyst of the catalytic converter.

6. The vehicle of claim 5 , wherein affecting the ratio of oxygen and hydrocarbons stored within the catalyst includes driving the ratio closer to a stoichiometric ratio.

7. The vehicle of claim 1 , wherein the engine is at idle.

8. The vehicle of claim 1 , wherein the one or more processors are configured to, if blocking criteria are not met, determine the load request for the engine based on at least the torque request and a stoichiometric air/fuel ratio.

9. The vehicle of claim 8 , wherein the blocking criteria include whether a speed of the vehicle is below a threshold value.

10. The vehicle of claim 8 , wherein the blocking criteria include whether the selected air/fuel ratio is different from a previously selected air/fuel ratio.

11. The vehicle of claim 1 , wherein determining the load request for the engine based on at least the torque request and the selected air/fuel ratio prevents a dip or surge in engine speed when the selected air/fuel ratio is different from a previously selected air/fuel ratio.

12. A method comprising:
with one or more processors disposed within a vehicle:
selecting an air/fuel ratio for an engine of the vehicle, wherein the selected air/fuel ratio is different from a stoichiometric air/fuel ratio;
selecting a torque request for the engine;
determining a load request for the engine based on at least the torque request and the selected air/fuel ratio; and

determining, based on the load request for the engine, at least one of a first output to a throttle actuator, a second output to a spark actuator, or a third output to a variable valve timing (VVT) actuator;
if the selected air/fuel ratio exceeds a threshold maximum, determining the load request for the engine based on at least the torque request and the threshold maximum; and
if the selected air/fuel ratio is less than a threshold minimum, determining the load request for the engine based on at least the torque request and the threshold minimum.

13. The method of claim 12 , wherein selecting the air/fuel ratio is based at least in part on a sensor reading from an air/fuel sensor located downstream of a catalytic converter in an exhaust system of the vehicle, and
wherein the air/fuel ratio is selected to improve performance of the catalytic converter by affecting a ratio of oxygen and hydrocarbons stored within a catalyst of the catalytic converter by driving the ratio closer to a stoichiometric ratio.

14. The method of claim 13 , further comprising: if blocking criteria are not met, determining the load request for the engine based on at least the torque request and a stoichiometric air/fuel ratio.

15. The method of claim 14 , wherein the blocking criteria include whether a speed of vehicle is below a threshold value.

16. The method of claim 14 , wherein the blocking criteria include whether the selected air/fuel ratio is different from a previously selected air/fuel ratio.

17. A system comprising:
a vehicle;
one or more processors disposed within the vehicle and configured to, if an engine of the vehicle is at idle:
select an air/fuel ratio for the engine of based at least in part on a sensor reading from an air/fuel sensor located downstream of a catalytic converter in an exhaust system of the vehicle, wherein the selected air/fuel ratio is different from a stoichiometric air/fuel ratio;
select a torque request for the engine;
if the selected air/fuel ratio exceeds a threshold maximum, determine a load request for the engine based on at least the torque request and the threshold maximum;
if the selected air/fuel ratio is less than a threshold minimum, determine the load request for the engine based on at least the torque request and the threshold minimum;
if the selected air/fuel ratio is between the threshold minimum and the threshold maximum, determine the load request for the engine based on at least the torque request and the selected air/fuel ratio; and
determine, based on the load request for the engine, at least one of a first output to a throttle actuator, a second output to a spark actuator, or a third output to a variable valve timing (VVT) actuator.

18. The system of claim 17 , wherein the one or more processors are further configured to:
if the selected air/fuel ratio exceeds a threshold maximum, determine the load request for the engine based on at least the torque request and the threshold maximum; and
if the selected air/fuel ratio is less than a threshold minimum, determine the load request for the engine based on at least the torque request and the threshold minimum.

Assignees

• Toyota Eng & Mfg North America
• Toyota Motor Co Ltd

Inventors

• Munson Garrett Parker
• Mcjunkin Adam C

Classifications

• F02D41/08

  for idling (F02D41/06, F02D41/16 take precedence) · CPC title

• F02D41/1439

  characterised by the position of the sensor · CPC title

• F02D2200/1002

  Output torque · CPC title

• F02D2200/501

  Vehicle speed · CPC title

• F02D2200/04

  Engine intake system parameters · CPC title