Automatic Transmission Control Device Shift Error Prevention

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Solution Overview

Problem

Automatic transmissions often experience degraded operability and drivability due to simultaneous downshift and upshift commands during manual operations, leading to misoperations that cancel out intended shifts.

Innovation Solution

A control apparatus that responds to manual upshift operations by forbidding the first opposite manual upshift during automatic or forced downshifts and permitting subsequent upshifts, ensuring shifts align with the driver's intentions by using a shift map and operational error prevention control processes.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Adaptability or versatility

If the control system allows manual upshift operations during automatic downshift, then the driver can override automatic shifts when needed, but simultaneous upshift and downshift commands cancel each other out and degrade operability

Engineering Contradiction:
Improvedriver's ability to override automatic shiftsVSAvoidoperability during manual operation
Core Design Contradiction:
Adaptability or versatilityVSEase of operation

Solution Approach 1:

The control device predicts the driver's intended shift operation based on accelerator pedal depression amount and vehicle speed before the actual manual operation occurs. By anticipating the driver's intent and preparing the appropriate shift response in advance, the system prevents command cancellation while maintaining natural driver control. The prediction mechanism compares anticipated operations with actual manual operations to determine whether to permit or forbid shift execution.

Inventive Principle:
Principle #10Preliminary action

2Reliability

If the control system forbids the first manual upshift operation during automatic downshift, then misoperations are nullified, but the driver's actual intention may be blocked

Engineering Contradiction:
Improveprevention of misoperationVSAvoiddriver's intended shift execution
Core Design Contradiction:
ReliabilityVSEase of operation

Solution Approach 1:

The control device performs preliminary prediction of the driver's intended shift operation by comparing accelerator pedal depression amount and vehicle speed against stored shift maps. This prediction occurs before the manual upshift command is fully executed, allowing the system to distinguish between accidental misoperations (forbidden) and intentional overrides (permitted) based on whether the predicted operation matches the actual manual operation.

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The control device continuously monitors accelerator pedal depression amount and vehicle speed to predict driver intent, then compares this prediction with actual manual upshift operations. This feedback loop allows the system to dynamically determine whether to forbid or permit each manual upshift command, ensuring that misoperations are blocked while genuine driver intentions are honored.

Inventive Principle:
Principle #23Feedback

Data Source

PatentEP2613070B8Control device of automatic transmission
Publication Date: 2018.03.21 JATCO LTD

AI summary

An automatic transmission has an automatic shift mode and a manual shift mode. When an opposite manual operation is performed, during an automatic shift based on a shift map in the automatic shift mode, in an opposite direction opposite to the automatic shift or when the opposite manual operation is performed, during a forced shift performed regardless of the manual operation in the manual shift mode, in the opposite direction opposite to the forced shift, a control apparatus forbids a shift based on a first manual operation and permits a shift based on a second or subsequent manual operation in the opposite direction opposite to the automatic shift or the forced shift.