Engine Control Apparatus for Manual Transmission Shift Shock Reduction

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Solution Overview

Problem

Manual transmission vehicles experience shift shock due to mismatched input and output rotational speeds when shifting gears, leading to delayed rotational speed synchronization of the engine, which affects drivability.

Innovation Solution

An engine control apparatus with a clutch release detecting component, time measuring component, and rotational speed synchronization control component that starts synchronization control after a prescribed delay, adjusting based on vehicle state and driver intent, to match engine speed with the predicted input rotational speed of the transmission.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If rotational speed synchronization control starts immediately when clutch is released, then shift shock is reduced, but engine rotational speed cannot decrease quickly enough during upshifting

Engineering Contradiction:
Improveshift shock reductionVSAvoidengine rotational speed adjustment speed
Core Design Contradiction:
ReliabilityVSSpeed

Solution Approach 1:

The control start determination unit determines whether to start rotational speed synchronization control before the clutch is fully released, based on predicted gear position and vehicle state. This preliminary determination allows the control to begin at the optimal moment - early enough to synchronize speeds properly, but not so early that it prevents quick speed adjustment during upshifting.

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The system dynamically adjusts the control start timing based on real-time conditions including predicted gear position, vehicle speed, and engine rotational speed. The control start determination unit evaluates multiple parameters to decide whether to initiate control, making the system adaptable to different driving scenarios rather than using fixed timing.

Inventive Principle:
Principle #15Dynamics

2Reliability

If rotational speed synchronization control starts before shifting, then synchronization is achieved, but drivability declines due to delayed speed matching

Engineering Contradiction:
Improverotational speed synchronizationVSAvoiddrivability
Core Design Contradiction:
ReliabilityVSEase of operation

Solution Approach 1:

The system performs preliminary determination of control start timing based on predicted post-shift gear position and current vehicle state. This allows the control to be ready to start immediately when conditions are right, achieving synchronization without delaying drivability.

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The control start determination unit continuously monitors vehicle speed, engine rotational speed, and predicted gear position to make real-time decisions about when to start synchronization control. This feedback mechanism ensures control starts at the optimal moment for both synchronization and drivability.

Inventive Principle:
Principle #23Feedback

Data Source

PatentEP1983177B1Engine control apparatus
Publication Date: 2014.06.18 NISSAN MOTOR CO LTD
  • EP1983177B1 patent drawingFigure 1
  • EP1983177B1 patent drawingFigure 2
  • EP1983177B1 patent drawingFigure 3

AI summary

An engine control apparatus basically has a clutch release detecting component, a time measuring component and a rotational speed synchronization control component. The clutch release detecting component detects when a clutch arranged between an engine and a manual transmission has been released to prevent rotation from being transferred from the engine to the manual transmission during shifting. The time measuring component measures an amount of time that elapses after the clutch is released. The rotational speed synchronization control component starts rotational speed synchronization control when the clutch is released and a prescribed delay time has elapsed since the clutch was released so that an engine rotational speed matches a predicted input rotational speed of the manual transmission being based on a vehicle speed and a gear position that is occurring after shifting is completed.