Vehicle Control Device for Simultaneous Pedal Operation
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Solution Overview
Problem
Existing vehicle control devices fail to maintain a constant rate of deceleration during simultaneous accelerator and brake operation, leading to increased brake operation requirements due to downshifting in automatic transmissions, which increases vehicle drive force.
Innovation Solution
Limiting downshifts or performing a forcible upshift in the transmission, along with output reducing control for the engine, to prevent an increase in drive force and simplify deceleration control during simultaneous accelerator and brake operation.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Power
If the transmission is downshifted in accordance with decrease in vehicle speed, then the drive force of the vehicle increases, but the brake operation amount must be increased to maintain constant deceleration rate
Solution Approach 1:
The control device applies preliminary anti-action by detecting simultaneous accelerator and brake operation, then proactively limiting downshifts before they can increase drive force and complicate braking control. The ECU prevents downshifts that would otherwise occur due to vehicle speed decrease, thereby counteracting the potential harmful effect of increased drive force during braking.
2Power
If the accelerator pedal operation amount is reduced to reduce engine output, then the drive force decreases, but the brake operation amount must be increased if the transmission downshifts
Solution Approach 1:
The invention extracts the problematic element (downshift) from the system during simultaneous accelerator and brake operation. By separating the downshift function from the normal speed-based control logic and applying a specific limitation during braking, the system eliminates the source of increased drive force that would otherwise require increased brake operation.
3Power
If output reducing control is applied to the drive source, then the engine output is reduced, but the reduction amount increases if downshift occurs simultaneously
Solution Approach 1:
The control device performs preliminary action by limiting downshifts before output reducing control needs to compensate for increased drive force. By preventing the downshift that would increase drive force, the system reduces the burden on subsequent output reducing control, allowing for smaller and simpler engine output reduction to achieve the desired braking effect.
Data Source
AI summary
When simultaneous depression of an accelerator pedal (2) and a brake pedal (4) is detected, an electronic control unit (1) inhibits a downshift of an automatic transmission (11) and performs output suppression control for an engine (6), thereby making it possible to suppress the increase of vehicle drive force caused by the downshift and maintain a constant vehicle deceleration rate by an easier operation.