Method and system for controlling the speed of an internal combustion engine driving a disengageable device

Patent metadata

Field	Value
Publication number	US-11560861-B2
Application number	US-201917287231-A
Country	US
Kind code	B2
Filing date	Oct 22, 2019
Priority date	Oct 22, 2018
Publication date	Jan 24, 2023
Grant date	Jan 24, 2023

Abstract

Disclosed is a method for regulating the speed of an engine which drives a disengageable device. The regulation of the engine speed is effected in accordance with a first mode when the disengageable device is disengaged and in accordance with a second mode when the disengageable device is engaged. The determination is effected by: —estimating the resistive torque exerted on the engine by the disengageable device; -changing a binary value from a first value representative of the disengaged state to a second value representative of the engaged state when the estimated resistive torque is higher than a first predetermined threshold for a first predetermined period of time; and —changing the binary value from the second value to its first value when, for a second predetermined period of time, the estimated resistive torque is lower than a second threshold possibly equal to the first threshold.

First claim

The invention claimed is:

1. A method for regulating a rotational engine speed of an internal combustion engine that drives a disengageable device in accordance with either of a first mode as a disengaged state wherein the disengageable device is not driven by the engine and a second mode as an engaged state wherein the disengageable device is driven by the engine, the method comprising:
determining whether the engine and the disengageable device are in one of the disengaged state and the engaged state, by carrying out the sub-steps of:
determining an estimated resistive torque exerted on the engine by the disengageable device,
comparing a value of the estimated resistive torque to a value of a first predetermined threshold torque, and when the value of the estimated resistive torque is higher than the value of the first predetermined threshold for a first predetermined period of time, changing a binary value from a first value representative of the disengaged state to a second value representative of the engaged state, and
comparing the value of the estimated resistive torque to a value of a second predetermined threshold torque, and when the value of the estimated resistive torque is lower than the value of the second predetermined threshold for a second predetermined period of time, changing said binary value from the second value to the first value; and

providing the binary value to an electronic management system of the engine.

2. The regulation method as claimed in claim 1 , wherein, during a change of the binary value from the second value to the first value, the second threshold has a value that is determined as a function of the rotational engine speed.

3. The regulation method as claimed in claim 1 , wherein a change of the binary value from the second value to the first value is carried out when, for the second predetermined period of time:
i) the estimated resistive torque is lower than the second threshold, and
ii) a variation in the rotational engine speed per unit time is higher than a predefined acceleration threshold.

4. The regulation method as claimed in claim 1 , wherein the estimated resistive torque exerted on the engine by the disengageable device is determined from a torque produced by combustion inside the engine, from which is subtracted both a torque associated with an internal friction in the engine and an acceleration torque that is calculated from

J
⁢

d
⁢

⁢
ω

dt

in which J corresponds to a moment of inertia of the disengageable device driven by the engine, and

d
⁢

⁢
ω

dt

in which is a variation of the rotational engine speed over time.

5. A method for regulating a rotational engine speed of an internal combustion engine that drives a disengageable device in accordance with either of a first mode as a disengaged state wherein the disengageable device is not driven by the engine and a second mode as an engaged state wherein the disengageable device is driven by the engine, the method comprising:
determining whether the engine and the disengageable device are in one of the disengaged state and the engaged state, by carrying out the sub-steps of:
estimating a resistive torque exerted on the engine by the disengageable device,
changing a binary value from a first value representative of the disengaged state to a second value representative of the engaged state when the estimated resistive torque is higher than a first predetermined threshold for a first predetermined period of time, and
changing said binary value from the second value to the first value when, for a second predetermined period of time, the estimated resistive torque is lower than a second threshold; and

providing the binary value to an electronic management system of the engine,
wherein when the system is in the engaged state, the following further steps are carried out:
when the estimated resistive torque is stable for a third predetermined period of time, determining a first instant at which the rotational engine speed passes a low speed threshold;
storing a first value representative of the estimated resistive torque;
determining a second instant at which the rotational engine speed passes a high speed threshold;
determining a value of a moment of inertia from the estimated resistive torque, from a variation in the rotational engine speed, and from a measured time interval used to obtain said variation of the rotational engine speed; and
when a difference between the determined value of the moment of inertia determined in the preceding step and a stored value of a moment of inertia of the disengageable device is outside a predetermined interval, modifying the stored value.

6. The regulation method as claimed in claim 5 , wherein the resistive torque exerted on the engine by the disengageable device is estimated from a torque produced by the combustion inside the engine, from which is subtracted both a torque associated with an internal friction in the engine and an acceleration torque that is calculated from

J
⁢

d
⁢

⁢
ω

dt

in which J corresponds to the moment of inertia of the disengageable device driven by the engine, and

d
⁢

⁢
ω

dt

in which is the variation of the rotational engine speed over time, and
wherein the stored value of the moment of inertia of the disengageable device is modified by ignoring a variation in the internal friction of the engine.

7. A non-transitory computer-readable medium on which is stored a computer program, comprising computer instructions that, upon execution by a computer, causes the computer to implement the method for regulating the speed of an internal combustion engine as claimed in claim 1 .

8. A device for regulating a speed of an internal combustion engine that drives a disengageable device, comprising:
means for determining an engine speed of the engine;
an electronic computer; and
regulation means for modifying the engine speed, wherein the electronic computer is configured to:
determine an estimated resistive torque exerted on the engine by the disengageable device,
compare a value of the estimated resistive torque to a value of a first predetermined threshold torque, and when the value of the estimated resistive torque is higher than the value of the first predetermined threshold for a first predetermined period of time, change a binary value from a first value representative of the disengaged state to a second value representative of the engaged state,
compare the value of the estimated resistive torque to a value of a second predetermined thresho

Assignees

• Vitesco Tech Gmbh

Inventors

• Moine Xavier

Classifications

• F02D2200/1004

  Estimation of the output torque · CPC title

• F02D41/022 Primary

  in relation with the clutch status · CPC title

• F02D2200/1006

  Engine torque losses, e.g. friction or pumping losses or losses caused by external loads of accessories · CPC title

• F02D2200/101

  Engine speed · CPC title

• F02D41/1497 Primary

  With detection of the mechanical response of the engine · CPC title