Vehicle Control Device Downshift Suppression During Attitude Adjustment
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Solution Overview
Problem
Concurrently executing vehicle attitude control and automatic transmission downshift control often results in inadequate torque reduction or increase, leading to compromised steering stability and extended downshift operation times.
Innovation Solution
A vehicle control device with an engine torque regulating mechanism, downshift control, and vehicle attitude control parts, which suppresses downshift control during vehicle attitude control to ensure torque reduction and vice versa, preventing overlapping execution periods to enhance steering stability.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Speed
If downshift control is executed to increase engine torque, then the gear ratio is increased and input rotational speed is increased, but the vehicle attitude control cannot be performed adequately because torque reduction is insufficient
Solution Approach 1:
The control device determines whether vehicle attitude control or downshift control should be prioritized in advance before executing either control. This preliminary determination prevents conflict between the two controls by establishing execution priority beforehand, ensuring that vehicle attitude control can be performed adequately even when downshift is requested.
Solution Approach 2:
The system dynamically adjusts the execution priority between vehicle attitude control and downshift control based on current vehicle conditions. The control determination unit evaluates the necessity of each control and flexibly determines which control should take precedence, allowing the system to adapt to changing driving conditions and maintain optimal vehicle attitude control.
2Reliability
If vehicle attitude control is executed to reduce engine torque, then steering stability is improved, but the downshift operation time is extended because torque increase is insufficient
Solution Approach 1:
The control determination unit makes a preliminary decision about which control to execute first by evaluating the current state. When vehicle attitude control is determined to be more necessary, it is executed first with full torque reduction capability, ensuring steering stability is maintained while downshift is delayed until the attitude control is complete.
Solution Approach 2:
The system automatically manages the conflict between the two controls without requiring external intervention. The control determination unit self-regulates by monitoring the execution status and necessity of each control, automatically switching priority as needed to ensure both controls can be performed effectively in sequence.
3Productivity
If both vehicle attitude control and downshift control are executed concurrently, then both controls are attempted simultaneously, but torque reduction or increase becomes inadequate leading to compromised performance
Solution Approach 1:
Before executing either control, the system performs a preliminary determination of which control has higher priority. This advance decision prevents concurrent execution conflicts by establishing a clear execution sequence, ensuring that the control with higher necessity is performed first with full effectiveness.
Solution Approach 2:
The system dynamically switches between different control execution modes based on real-time conditions. When one control becomes less necessary, the system dynamically transitions to executing the other control, ensuring that torque adjustments are always adequate for the current priority control without being compromised by simultaneous conflicting demands.
Data Source
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AI summary
A vehicle control device comprises: a downshift control part 51 configured, upon issuance of a downshift request for downshifting an automatic transmission 200, to execute a downshift control of downshifting the automatic transmission 200 and driving an engine torque regulating mechanism to increase an output torque of an engine 10; a vehicle attitude control part 53 configured, upon satisfaction of a condition that the vehicle is traveling and a steering angle-related value pertaining to a steering angle of a steering device increases, to execute a vehicle attitude control of reducing the output torque of the engine 10 to generate deceleration of the vehicle so as to control vehicle attitude; and a downshift suppression part 55 configured, when the vehicle attitude control is executed, to suppress the execution of the downshift control.