Engine Controller Crank Counter Map Integration

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Solution Overview

Problem

Existing control systems for internal combustion engines face increased processing loads due to varying engine rotation speeds, which can lead to inefficient fuel injection and potential low fuel pressure issues when counting the driving times of high pressure fuel pumps.

Innovation Solution

A control system that acquires crank counter values at fixed time intervals, uses a map to calculate the number of driving times based on top dead center positions, and integrates these values to maintain consistent processing intervals, ensuring accurate counting and preventing low fuel pressure conditions.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If the controller checks the crank counter value changes at every fixed crank angle to count the number of driving times of the high pressure fuel pump, then the number of driving times can be counted accurately, but the processing load of the controller becomes too large when engine rotation speed becomes high

Engineering Contradiction:
Improveaccuracy of counting driving timesVSAvoidprocessing load
Core Design Contradiction:
Measurement precisionVSProductivity

Solution Approach 1:

The patent pre-calculates and stores in a lookup table the number of crank counter value changes that occur at each possible crank angle position during one camshaft rotation. This preliminary computation allows the controller to simply query the table during runtime instead of performing complex real-time counting, thereby maintaining accurate driving time measurement while significantly reducing the processing load during high-speed operation.

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The patent creates a simplified representation (lookup table) of the crank counter value change patterns. Instead of directly processing the actual crank angle changes in real-time, the controller uses pre-computed data from the lookup table to determine the number of driving times, effectively copying the essential information needed for accurate counting while avoiding the computational complexity of real-time analysis.

Inventive Principle:
Principle #26Copying

2Measurement precision

If the controller counts the number of driving times by checking crank counter changes at every fixed crank angle, then accurate counting is achieved, but the interval at which processing is performed becomes shorter as engine rotation speed increases

Engineering Contradiction:
Improveaccuracy of driving time countingVSAvoidprocessing interval
Core Design Contradiction:
Measurement precisionVSLoss of time

Solution Approach 1:

The patent performs the complex analysis of crank counter value changes in advance during engine operation at normal speeds, storing the results in a lookup table. During high-speed operation, the controller simply queries this pre-computed table, eliminating the need for continuous real-time processing and thereby maintaining accurate counting while extending the processing interval to avoid time loss.

Inventive Principle:
Principle #10Preliminary action

Applied Scientific Principles

This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.

Function Achieved in This Case

This approach reduces processing load variability with engine speed changes and ensures fuel injection only when the high pressure fuel pressure is sufficient, preventing in-cylinder fuel injection at low pressure conditions.

Implementation Method 1

a pump cam 67 provided on a camshaft 25 that rotates in conjunction with a rotation of a crankshaft 18

Methodology Applied
Scientific EffectCam mechanism: Cam

Implementation Method 2

a volume of a fuel chamber 63 is increased and is decreased and fuel is pressurized by a reciprocating motion of a plunger 62

Methodology Applied
Scientific EffectReciprocating motion:

Data Source

PatentEP3722579B1Control system for internal combustion engine, and internal combustion engine
Publication Date: 2023.06.07 TOYOTA JIDOSHA KK
  • EP3722579B1 patent drawingFigure 1
  • EP3722579B1 patent drawingFigure 2
  • EP3722579B1 patent drawingFigure 3~4

AI summary

A control system includes a controller (100). The controller (100) acquires a crank counter value each time a fixed time elapses. The controller (100) calculates the number of the crank counter values corresponding to the top dead center of the plunger (62) between a previously acquired crank counter value and a currently acquired crank counter value with reference to the map each time the crank counter value is acquired and calculate the number of driving times of the high pressure fuel pump (60) by integrating the calculated number.