Engine control unit

Patent metadata

Field	Value
Publication number	US-9243574-B2
Application number	US-201113326884-A
Country	US
Kind code	B2
Filing date	Dec 15, 2011
Priority date	Dec 17, 2010
Publication date	Jan 26, 2016
Grant date	Jan 26, 2016

Abstract

To prevent a reduction in engine load detection accuracy due to variations in reluctor size within mass production tolerances, an engine control unit includes a pulse generator PC that detects a reluctor to output crank pulses. An angular velocity calculating unit calculates a first crank angular velocity on the basis of an interval between two crank pulses output in a predetermined section near compression top dead center TDC, and detects near overlap top dead center OLP the same reluctor used for calculating the first crank angular velocity to calculate a second crank angular velocity on the basis of an interval between generated two crank pulses. An engine load estimating unit calculates, as an engine load, a difference between the first crank angular velocity and the second crank angular velocity. The engine load is indicated mean effective pressure over a whole cycle including negative work done by the engine.

First claim

We claim:

1. An engine control unit comprising:
a pulse generator that detects a reluctor provided on a crank pulser rotor rotating synchronously with a crankshaft of a single cylinder engine to output crank pulses;
an angular velocity calculator that calculates a first crank angular velocity using a reluctor in a predetermined section near compression top dead center of the engine in a compression stroke and an interval between two crank pulses output in the predetermined section near the compression top dead center of the engine, and detects near overlap top dead center the same reluctor used for calculating the first crank angular velocity to calculate a second crank angular velocity in an exhaust stroke using an interval between two crank pulses output from the pulse generator; and
an engine load estimator that estimates an engine load from a difference between the first crank angular velocity and the second crank angular velocity,
wherein the two crank pulses to be output in each of predetermined sections near the compression top dead center and the overlap top dead center are output at a time of detection of front and rear ends of a single reluctor provided on the crank pulser rotor.

2. The engine control unit according to claim 1 , wherein a relationship between the reluctor and the crankshaft is set such that the two crank pulses to be output in each of predetermined sections near the compression top dead center and the overlap top dead center are output in positions immediately before the compression top dead center and the overlap top dead center.

3. The engine control unit according to claim 2 , wherein the engine load estimator estimates the engine load from indicated mean effective pressure over a whole cycle of the engine including a pumping loss that is negative work done by the engine.

4. The engine control unit according to claim 1 , wherein the engine load estimator estimates the engine load from indicated mean effective pressure over a whole cycle of the engine including a pumping loss that is negative work done by the engine.

5. An engine control unit comprising:
a pulse generator that detects a reluctor provided on a crank pulser rotor rotating synchronously with a crankshaft of a single cylinder engine to output crank pulses;
an angular velocity calculator that calculates a first crank angular velocity using a reluctor in a predetermined section near compression top dead center of the engine in a compression stroke and an interval between two crank pulses output in the predetermined section near the compression top dead center of the engine, and detects near overlap top dead center the same reluctor used for calculating the first crank angular velocity to calculate a second crank angular velocity in an exhaust stroke using an interval between two crank pulses output from the pulse generator; and
an engine load estimator that estimates an engine load from a difference between the first crank angular velocity and the second crank angular velocity,
wherein a relationship between the reluctor and the crankshaft is set such that the two crank pulses to be output in each of predetermined sections near the compression top dead center and the overlap top dead center are output in positions of the same physical reluctor straddling both the compression top dead center in the compression stroke and the overlap top dead center in the exhaust stroke.

6. The engine control unit according to claim 5 , wherein the two crank pulses to be output in each of predetermined sections near the compression top dead center and the overlap top dead center are output at a time of detection of front and rear ends of a single reluctor provided on the crank pulser rotor.

7. The engine control unit according to claim 5 , wherein the engine load estimator estimates the engine load from indicated mean effective pressure over a whole cycle of the engine including a pumping loss that is negative work done by the engine.

8. A method of controlling an engine with an engine control unit comprising:
detecting, by a pulse generator, a reluctor provided on a crank pulser rotor rotating synchronously with a crankshaft of a single cylinder engine to output crank pulses;
calculating, by the engine control unit, a first crank angular velocity using a reluctor in a predetermined section near compression top dead center of the engine in a compression stroke and an interval between two crank pulses output in the predetermined section near the compression top dead center of the engine, and detecting near overlap top dead center of the same reluctor used for calculating the first crank angular velocity to calculate a second crank angular velocity in an exhaust stroke using an interval between two crank pulses output from the pulse generator; and
estimating, by the engine control unit, an engine load from a difference between the first crank angular velocity and the second crank angular velocity,
wherein the two crank pulses to be output in each of predetermined sections near the compression top dead center and the overlap top dead center are output at a time of detection of front and rear ends of a single reluctor provided on the crank pulser rotor.

9. The method of controlling an engine according to claim 8 , wherein a relationship between the reluctor and the crankshaft is set such that the two crank pulses to be output in each of predetermined sections near the compression top dead center and the overlap top dead center are output in positions immediately before the compression top dead center and the overlap top dead center.

10. The method of controlling an engine according to claim 8 , further comprising: estimating the engine load from indicated mean effective pressure over a whole cycle of the engine including a pumping loss that is negative work done by the engine.

11. A method of controlling an engine comprising:
detecting, by a pulse generator, a reluctor provided on a crank pulser rotor rotating synchronously with a crankshaft of a single cylinder engine to output crank pulses;
calculating, by the engine control unit, a first crank angular velocity using a reluctor in a predetermined section near compression top dead center of the engine in a compression stroke and an interval between two crank pulses output in the predetermined section near the compression top dead center of the engine, and detecting near overlap top dead center of the same reluctor used for calculating the first crank angular velocity to calculate a second crank angular velocity in an exhaust stroke using an interval between two crank pulses output from the pulse generator; and
estimating, by the engine control unit, an engine load from a difference between the first crank angular velocity and the second crank angular velocity,
wherein a relationship between the reluctor and the crankshaft is set such that the two crank pulses to be output in each of predetermined sections near the compression top dead center and the overlap top dead center are output in positions of the same physical reluctor straddling both the compression top dead center in the compression stroke and the overlap top dead center in the exhaust stroke.

12. The method of controlling an engine according to claim 11 , wherein the two crank pulses to be output in each of predetermined sections near the compression top dead center and the overlap top dead center are output at a time of detection of front and rear ends of a single reluctor provided on the crank pulser rotor.

Assignees

• Nishida Kenji
• Kaneko Tetsuya
• Sasaki Tomiyuki
• Aoki Koji
• Imao Ranju
• Fukuzawa Kazuto
• Honda Motor Co Ltd

Inventors

• Nishida Kenji
• Kaneko Tetsuya
• Sasaki Tomiyuki
• Aoki Koji
• Imao Ranju
• Fukuzawa Kazuto

Classifications

• G01D5/24428

  Error prevention · CPC title

• G01D5/147

  influenced by the movement of a third element, the position of Hall device and the source of magnetic field being fixed in respect to each other · CPC title

• F02P5/151

  with means for compensating the variation of the characteristics of the engine or of a sensor, e.g. by ageing · CPC title

• G01P3/488

  delivered by variable reluctance detectors · CPC title

• F02D41/0097 Primary

  using means for generating speed signals · CPC title