Vehicle Gear Shift Mode Switch Control Device
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Solution Overview
Problem
Conventional control systems for vehicles with switchable automatic and manual gear shift modes often result in sudden changes in drive force when switching between modes, leading to an unpleasant experience for the driver, as the initial gear stage or ratio selected does not align with the driver's intention or expected sensation.
Innovation Solution
A control device that adjusts the initial gear stage or ratio during mode switches to minimize the change in drive force or ensure it aligns with the driver's intention, by selecting a gear stage or ratio that offers the lowest change in drive force or matches the driver's intended acceleration or deceleration, using sensors to determine the driver's intent from accelerator pedal operations.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Stability of the object's composition
If the initial gear stage is set based on the previous automatic gear stage when switching from automatic to manual mode, then the gear stage continuity is maintained, but the drive force changes suddenly causing driver discomfort
Solution Approach 1:
The patent changes the parameter selection criteria for the initial gear stage in manual mode. Instead of simply maintaining the previous automatic gear stage, the system selects a gear stage that minimizes drive force change by comparing drive force characteristics across different gear stages. This parameter optimization resolves the contradiction by maintaining continuity while preventing sudden harmful changes in drive force.
2Object-affected harmful factors
If the initial gear stage is selected to minimize drive force change, then driver comfort is improved, but the gear stage may not align with driver intention for acceleration or deceleration
Solution Approach 1:
The patent incorporates feedback from multiple sensors including accelerator pedal position, vehicle speed, and engine load to determine driver intention. This feedback mechanism allows the system to distinguish between situations where the driver wants acceleration versus deceleration, and selects the initial gear stage accordingly. The feedback loop resolves the contradiction by ensuring both comfort and alignment with driver intent.
3Ease of operation
If the gear stage is selected based on driver acceleration intention, then the drive force aligns with driver expectation, but the drive force change may be large causing discomfort
Solution Approach 1:
The patent applies partial action by selectively adjusting the gear stage selection based on the degree of accelerator depression. For moderate acceleration requests, it selects a gear stage that provides adequate acceleration while limiting excessive drive force changes. For strong acceleration requests, it allows more significant drive force changes. This partial application of gear optimization resolves the contradiction between alignment and comfort.
Data Source
AI summary
Provided is a control device for a vehicle that can switch between an automatic gear shift mode in which gear shifting of the automatic transmission is performed according to a vehicle traveling condition, and a manual gear shift mode in which gear shifting of the automatic transmission is performed according to a driver operation, and that changes drive force characteristics by controlling output torque of the drive source at the time of a gear shift mode switch. When the gear shift mode is switched between automatic and manual the control device selects an initial gear stage or an initial gear ratio for the gear shift mode switch such that the amount of change in drive force that accompanies the gear shift mode switch decreases, or such that the direction of change in drive force that accompanies the gear shift mode switch conforms to the driver's intention or expected sensation.