Vehicle Control Device for Rapid Transmission Shift Formation
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Solution Overview
Problem
In vehicles with internal combustion engines and transmission apparatuses, there is a challenge in quickly forming a transmission shift stage when the vehicle is traveling in a neutral state with increasing speed, leading to delays in power transmission and reduced acceleration due to negative torque transfer.
Innovation Solution
A vehicle control device that controls the rotation speed of the internal combustion engine to ensure the transmission shift input member's rotation speed exceeds the post-transmission-shift input rotation speed, allowing for quick engagement of engagement devices and prevention of negative torque transfer, thereby facilitating rapid formation of transmission shift stages.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Use of energy by moving object
If the vehicle travels on a downhill with the transmission apparatus kept in the neutral state, then fuel consumption is reduced during inertial travel, but the rotation speed difference between the rotary member close to the wheels and the rotary member close to the internal combustion engine increases, causing response delay when forming a transmission shift stage
Solution Approach 1:
The control device performs preliminary action by controlling the internal combustion engine to rotate at a predetermined rotation speed before the driver operates the accelerator. This ensures that when the transmission shift stage needs to be formed, the rotation speed of the rotary member close to the internal combustion engine is already close to the rotation speed of the rotary member close to the wheels, enabling immediate engagement of the engagement device without response delay.
Solution Approach 2:
The control device dynamically adjusts the rotation speed of the internal combustion engine based on the vehicle's travel state. During inertial travel on downhill, the engine maintains a specific rotation speed that prepares the transmission system for rapid engagement when needed, rather than keeping the transmission apparatus in a completely passive neutral state.
2Productivity
If the rotation speed of the internal combustion engine is increased to form a transmission shift stage quickly, then the transmission shift stage can be formed promptly, but the rotation speed mismatch between engagement devices may cause negative torque transfer to the wheels
Solution Approach 1:
The control device uses feedback by continuously monitoring the rotation speed of the internal combustion engine and the travel state of the vehicle. Based on this feedback, it precisely controls the engine rotation speed to match the required predetermined speed, ensuring that when the transmission shift stage is formed, the rotation speeds are synchronized and negative torque transfer is prevented.
Solution Approach 2:
The control device changes the parameter of engine rotation speed to a specific predetermined value that optimizes the balance between rapid transmission shift stage formation and prevention of negative torque transfer. This parameter control ensures smooth engagement of the engagement device without causing harmful torque reversal.
Data Source
AI summary
A vehicle control device for controlling a vehicle driving device including an internal combustion engine as a driving force source for a wheel and a transmission apparatus, wherein the transmission apparatus includes a transmission shift input member drivably coupled to the internal combustion engine, a transmission shift output member drivably coupled to the wheel, and a transmission mechanism having a plurality of engagement devices and selectively forming a plurality of transmission shift stages having different transmission shift ratios depending on engagement states of the plurality of engagement devices.