Variable droop engine speed control system
First Claim
1. A method of controlling the engine speed of an internal combustion engine having a throttle position sensor associated therewith for sensing throttle position, an engine speed sensor for sensing actual engine speed, and a fuel system responsive to a fuel control signal to fuel the engine, the method comprising the steps of:
- (1) sensing throttle position and determining a desired engine speed therefrom;
(2) sensing actual engine speed;
(3) determining an error speed to be the difference between the desired engine speed and the actual engine speed;
(4) generating a fuel control signal from the error speed that is a function of at least the magnitude, duration and rate of change of the error speed, the fuel control signal further being proportional to engine load such that the actual engine speed decreases as engine load increases; and
(5) fueling the engine in accordance with the fuel control signal to thereby control the actual engine speed.
2 Assignments
0 Petitions
Accused Products
Abstract
A variable droop engine speed control system includes a proportional-integral-derivative (PID) engine speed controller as its central component. The PID controller includes the standard proportional, integral and derivative gains associated with the proportional, integral and derivative portions of the controller, and further includes a droop gain associated only with the integral portion. The PID transfer function has a pole associated strictly with the droop gain such that a full range of droop may be provided by varying only the droop gain. Varying the droop gain affects only the steady-state frequency response of the PID so that its dynamic compensation is not disturbed by varying the amount of droop
-
Citations
19 Claims
-
1. A method of controlling the engine speed of an internal combustion engine having a throttle position sensor associated therewith for sensing throttle position, an engine speed sensor for sensing actual engine speed, and a fuel system responsive to a fuel control signal to fuel the engine, the method comprising the steps of:
-
(1) sensing throttle position and determining a desired engine speed therefrom; (2) sensing actual engine speed; (3) determining an error speed to be the difference between the desired engine speed and the actual engine speed; (4) generating a fuel control signal from the error speed that is a function of at least the magnitude, duration and rate of change of the error speed, the fuel control signal further being proportional to engine load such that the actual engine speed decreases as engine load increases; and (5) fueling the engine in accordance with the fuel control signal to thereby control the actual engine speed. - View Dependent Claims (2, 3)
-
-
4. A method of providing variable droop in an electronic engine speed governor having a proportional portion, an integral portion and a derivative portion associated therewith, the governor having a transfer function that is a function of the proportional, integral and derivative portions, the method comprising the steps of:
-
(1) configuring the governor such that its transfer function has a pole associated with the integral portion; (2) providing the integral portion with a droop gain associated with the integral portion pole; and (3) varying the magnitude of the droop gain to thereby vary the location of the integral portion pole, the location of the integral portion pole determining the amount of droop in the engine speed governor. - View Dependent Claims (5, 6, 7, 8)
-
-
9. A method of providing variable droop in an electronic engine speed governor having a proportional portion, an integral portion and a derivative portion, the governor having a frequency response associated therewith, the method comprising the steps of:
-
(1) configuring the governor such that the magnitude of only its steady-state frequency response is dependent upon a droop gain associated with the integral portion; and (2) varying the magnitude of the droop gain to thereby vary the steady state frequency response magnitude, the magnitude of the steady-state frequency response determining the amount of droop in the engine speed governor. - View Dependent Claims (10)
-
-
11. A control system for controlling the speed of an internal combustion engine having a throttle comprising:
-
a throttle position sensor for sensing throttle position and providing a throttle position signal corresponding thereto; an engine speed sensor for sensing engine speed and providing an engine speed signal corresponding thereto; a fueling system responsive to a fuel control signal to fuel the engine; and an engine speed controller responsive to said throttle position signal to provide a reference speed signal corresponding thereto, said controller being responsive to said reference speed signal and said engine speed signal to determine an error speed signal corresponding to the difference therebetween, said controller being further responsive to said error speed signal to generate said fuel control signal from said error speed signal, said fuel control signal being a function of at least the magnitude, duration and rate of change of said error speed signal and further being proportional to engine load such that said engine speed decreases as engine load increases. - View Dependent Claims (12, 13, 14, 15)
-
-
16. A variable droop electronic engine speed governor for use in a control system for controlling the speed of an internal combustion engine, comprising:
-
an error speed input for receiving an engine speed error signal thereat; a fuel control output for providing a fuel control signal thereat; and an engine speed error correction portion defining a transfer function having at least one pole, the location of said pole being variable to thereby provide said governor with a variable range of droop; wherein said engine speed governor is responsive to said engine speed error signal to provide said fuel control signal to the engine fueling system in accordance with said transfer function. - View Dependent Claims (17)
-
-
18. A variable droop electronic engine speed governor for use in a control system for controlling the speed of an internal combustion engine, comprising:
-
an error speed input for receiving an engine speed error signal thereat; a fuel control output for providing a fuel control signal thereat; and an engine speed error correction portion having a frequency response associated therewith, the magnitude of only the steady-state portion of said frequency response being variable to thereby provide the engine speed governor with a correspondingly variable range of droop; wherein said engine speed governor is responsive to said engine speed error signal to provide said fuel control signal to the engine fueling system in accordance with said frequency response. - View Dependent Claims (19)
-
Specification