Engine Idle Control via Steering Angle Torque Compensation

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Solution Overview

Problem

Conventional idle control systems for vehicle engines face challenges in maintaining stability and efficiency, particularly when external loads fluctuate during steering operations, leading to potential engine stalling and increased energy loss.

Innovation Solution

The engine controlling apparatus sets a torque value based on the steering angle and adjusts the intake air amount and ignition timing to increase the maximum torque at the Minimum Spark Advance for Best Torque (MBT), thereby enhancing idle stability and reducing fuel cost by considering load fluctuations during steering operations.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If the idle speed is set higher in advance to avoid engine stall, then the engine stability is improved, but the energy loss increases and fuel cost deteriorates

Engineering Contradiction:
Improveengine stabilityVSAvoidenergy loss
Core Design Contradiction:
ReliabilityVSLoss of energy

Solution Approach 1:

The patent applies dynamics by making the target idle speed variable rather than fixed. The ECU dynamically adjusts the target idle speed based on detected steering operation amounts, adding a steering correction term to the basic idle speed. This allows the system to adapt to changing load conditions during steering operations, maintaining engine stability only when necessary while avoiding unnecessary energy consumption during normal operation.

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The patent changes the parameter of idle speed from a constant value to a variable value that responds to steering operations. By calculating a steering correction term based on the steering operation amount and adding it to the basic idle speed, the system adjusts the target idle speed parameter dynamically. This resolves the contradiction by increasing idle speed only during steering operations when load fluctuation occurs, rather than maintaining a consistently high idle speed.

Inventive Principle:
Principle #35Parameter changes

2Reliability

If the intake air amount is controlled greater in advance to maintain idle stability, then the engine stall is prevented, but the engine rotates excessively and fuel cost increases

Engineering Contradiction:
Improveidle stabilityVSAvoidfuel efficiency
Core Design Contradiction:
ReliabilityVSProductivity

Solution Approach 1:

The patent implements feedback control by continuously detecting the steering operation amount and adjusting the target idle speed accordingly. The ECU calculates a steering correction term based on the detected steering amount and adds it to the basic idle speed to determine the target idle speed. This feedback mechanism ensures that additional intake air is supplied only when steering operations create load fluctuations, rather than continuously supplying excess air, thus maintaining idle stability only when needed and improving fuel efficiency.

Inventive Principle:
Principle #23Feedback

3Device complexity

If conventional idle control based on angular speed is used, then the control system is simple, but it is difficult to calculate accurate external load values and idle stability degrades

Engineering Contradiction:
Improvecontrol system complexityVSAvoididle stability
Core Design Contradiction:
Device complexityVSReliability

Solution Approach 1:

The patent changes the control parameter from angular speed to steering operation amount (steering angle). By detecting the steering operation amount instead of relying on angular speed calculations, the system directly measures the parameter that correlates with external load during steering operations. This provides more accurate information for calculating the steering correction term, improving idle stability without significantly increasing system complexity.

Inventive Principle:
Principle #35Parameter changes

Data Source

PatentEP2436914B1Engine controlling apparatus
Publication Date: 2023.12.27 MITSUBISHI MOTORS CORP
  • EP2436914B1 patent drawingFigure 1
  • EP2436914B1 patent drawingFigure 2~3
  • EP2436914B1 patent drawingFigure 4A~4B

AI summary

An engine controlling apparatus includes an idle speed setting unit (2a) that sets a target idle speed upon idling of an engine mounted on a vehicle, and a target torque setting unit (2a) that sets a target torque in response to the target idle speed. The apparatus further includes an ignition timing controlling unit (4a) that controls an ignition timing and an intake air amount controlling unit (4b) that controls an intake air amount, and a steering angle detection unit (8) that detects a steering angle. The apparatus further includes a torque value setting unit (3) that sets a torque value in response to the steering angle. The intake air amount controlling unit (4b) controls the intake air amount in response to both the target torque and the torque value. The ignition timing controlling unit (4a) controls the ignition timing so that the engine outputs the target torque.