ELECTRONIC GOVERNOR SYSTEM AND LOAD SENSING SYSTEM

• US 20150315982A1
• Filed: 05/01/2015
• Published: 11/05/2015
• Est. Priority Date: 05/01/2014
• Status: Active Grant

• Current Assignee: Briggs & Stratton LLC (Briggs & Stratton Corporation)
• Original Assignee: Briggs & Stratton Corporation
• Inventors: Koenen, Robert, Brueck, Daniel
• Granted Patent: US 9,909,511 B2
• Time in Patent Office: Days
• US Class Current: 1/1
• CPC Class Codes: F02D 11/10 of the electric type
• CPC Class Codes: F02D 2009/0208 for small engines
• CPC Class Codes: F02D 2009/0213 Electronic or electric governor
• CPC Class Codes: F02D 2009/022 Throttle control function parameters
• CPC Class Codes: F02D 2009/023 Engine speed
• CPC Class Codes: F02D 2009/0261 having a specially shaped transmission member, e.g. a cam, specially toothed gears, with a clutch
• CPC Class Codes: F02D 2200/0404 Throttle position
• CPC Class Codes: F02D 2200/1004 Estimation of the output torque
• CPC Class Codes: F02D 2200/101 Engine speed
• CPC Class Codes: F02D 2400/14 Power supply for engine control systems
• CPC Class Codes: F02D 31/002 controlling air supply
• CPC Class Codes: F02D 41/1402 Adaptive control
• CPC Class Codes: F02D 9/02 concerning induction conduits throttle valves, or arrangements thereof in conduits F02D9/08
• CPC Class Codes: F02D 9/1065 Mechanical control linkage between an actuator and the flap, e.g. including levers, gears, springs, clutches, limit stops of the like
• CPC Class Codes: F02P 9/005 by weakening or suppression of sparks to limit the engine speed
• CPC Class Codes: F16H 2035/003 Gearings comprising pulleys or toothed members of non-circular shape, e.g. elliptical gears
• CPC Class Codes: F16H 2035/005 Gearings or mechanisms preventing back-driving
• CPC Class Codes: F16H 35/00 Gearings or mechanisms with other special functional features
• CPC Class Codes: Y10T 74/18568 Reciprocating or oscillating to or from alternating rotary

Abstract

An electronic governor system includes a motor, a transmission coupled to the motor, a throttle plate coupled to the transmission, the throttle plate movable to multiple positions between closed and wide-open, wherein power is supplied to the motor to move the throttle pate to a desired position and wherein power is not supplied to the motor to maintain the throttle plate in the desired position.

Claims

1. An electronic governor system, comprising:

a motor;

a transmission coupled to the motor;

a throttle plate coupled to the transmission, the throttle plate movable to a plurality of positions between closed and wide-open;

wherein power is supplied to the motor to move the throttle pate to a desired position; and

wherein power is not supplied to the motor to maintain the throttle plate in the desired position.

2. The electronic governor system of claim 1, a reduction ratio of the transmission is greater than or equal to 40:

1.

3. The electronic governor system of claim 1, further comprising:

an elliptical gear set coupling the transmission to the throttle plate, the elliptical gear set including a driven elliptical gear coupled to the transmission and a driving elliptical gear coupled to the throttle plate;

wherein, when the throttle plate is near the wide open position, a major radius of the driving elliptical gear engages a minor radius of the driven elliptical gear; and

wherein, when the throttle plate is near the closed position, a minor radius of the driving elliptical gear engages a major radius of the driven elliptical gear.

4. The electronic governor system of claim 1, further comprising:

an ignition system configured to produce excess energy; and

an energy storage device configured to store the excess energy and to power the motor with the stored excess energy.

5. The electronic governor system of claim 4, wherein the excess energy comprises at least one positive spark.

6. An electronic governor system, comprising:

a motor;

a transmission coupled to the motor;

a throttle plate coupled to the transmission, the throttle plate movable to a plurality of positions between closed and wide-open;

an engine speed sensor; and

a controller including a feedback control module and an adaptive control module;

wherein the feedback control module is configured to;

determine an engine speed error based on a comparison of a current engine speed input signal from the engine speed sensor and a desired engine speed; and

provide an engine speed output signal to the motor to control the position of the throttle plate to correct the engine speed error, wherein the engine speed output signal is determined by a control algorithm using the engine speed error as an input;

wherein the adaptive control module is configured to;

determine an expected engine speed error correction based on the engine speed output signal provided by the feedback control module;

determine an actual engine speed error correction based on a current engine speed input signal from the engine speed sensor and a previous engine speed input signal from the engine speed sensor;

determine a correction error based on the expected engine speed error correction and the actual engine speed correction; and

adjust a parameter of the control algorithm of the feedback control module when the correction error is within a predetermined range or outside of a predetermined range.

7. The electronic governor system of claim 6, wherein the feedback control module utilizes a proportional-integral-derivative control algorithm to provide the engine speed output signal and the parameter adjusted by the adaptive control module is at least one of a proportional parameter, an integral parameter, and a derivative parameter.

8. The electronic governor system of claim 7, wherein the proportional-integral-derivative control algorithm utilizes a plurality of parameter sets, each parameter set including a proportional parameter, an integral parameter, and a derivative parameter, and wherein the feedback control module is configured to utilize a specific parameter set based on the position of the throttle plate.

9. The electronic governor system of claim 8, wherein a first parameter set is utilized by the proportional-integral-derivative control algorithm when the throttle plate is near the closed position and a second parameter set is utilized by the proportional-integral-derivative control algorithm when the throttle plate is near the wide-open position.

10. The electronic governor system of claim 8, further comprising a temperature sensor configured to detect a temperature, wherein a first parameter set is utilized by the proportional-integral-derivative control algorithm when the detected temperature is below a threshold and a second parameter set is utilized by the proportional-integral-derivative control algorithm when the detected temperature is above the threshold.

11. The electronic governor system of claim 6, wherein the feedback control module utilizes a fuzzy logic control algorithm to provide the engine speed output signal and the parameter adjusted by the adaptive control module is at least one parameter of at least one rule of the fuzzy logic control algorithm.

12. The electronic governor system of claim 11, further comprising a temperature sensor configured to detect a temperature, wherein the detected temperature is an input to the fuzzy logic control algorithm.

13. The electronic governor system of claim 6, further comprising an ignition system, wherein excess energy from the ignition system is used to power the motor.

14. The electronic governor system of claim 6, wherein power is not supplied to the motor when the throttle plate position is not changing.

15. The electronic governor system of claim 6, wherein the adaptive control module is configured to adjust a parameter of the feedback control module such that a subsequent engine speed output signal is more aggressive when the expected engine speed error correction is less than the actual engine speed correction.

16. The electronic governor system of claim 6, wherein the adaptive control module is configured to adjust a parameter of the feedback control module such that a subsequent engine speed output signal is less aggressive when the expected engine speed error correction is greater than the actual engine speed correction.

17. A four-cycle small internal combustion engine, comprising:

an engine speed sensor configured to detect an engine speed;

an electronic governor system configured to change an engine operating speed in response to a load input; and

a load sensing system configured to determine an engine load based on changes in the detected engine speed and provide the load input to the electronic governor system based on the determined engine load.

18. The engine of claim 17, wherein the electronic governor system is configured to provide at least two operating modes, wherein the electronic governor system is configured to set the engine operating speed to a first speed in the first operating mode and set the engine operating speed to a second speed greater than the first speed in the second operating mode.

19. The engine of claim 18, wherein the electronic governor system is configured to implement the first operating mode when the load input is below a first predetermined threshold value and implement the second operating mode when the load input is above a second predetermined threshold value.

20. The engine of claim 19, wherein the first predetermined threshold value and the second predetermined threshold value are the same.