Vehicle Control Apparatus for Step-Variable Transmission
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Solution Overview
Problem
Existing vehicle control apparatuses for step-variable transmissions face challenges in reducing synchronizing shock during coasting shift-down actions, particularly when the rate of change of vehicle running speed is low, leading to either slow progress or excessive rapid rise in input speed, which can result in synchronizing shock or prolonged shift times.
Innovation Solution
A control apparatus that temporarily increases the input torque of the step-variable transmission beyond the required value during coasting shift-down actions, with the amount of increase varying based on the rate of change of vehicle running speed, and includes a torque increasing amount setting portion to adjust the input torque to prevent synchronizing shock and ensure timely completion of the shift-down action.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Speed
If the input torque is increased by a predetermined constant amount to raise the input speed, then the input speed reaches the synchronization value faster, but the coasting shift-down action progresses slowly when the rate of change of vehicle running speed is relatively high
Solution Approach 1:
The patent applies dynamics by making the torque increase amount variable rather than constant. The control apparatus dynamically adjusts the torque increase amount based on the rate of change of vehicle running speed, allowing the system to adapt to different driving conditions and optimize both shift speed and completion time
Solution Approach 2:
The patent changes the parameter of torque increase amount from a fixed constant value to a variable value that depends on the rate of change of vehicle running speed. This parameter change allows the system to optimize performance across different operating conditions by adjusting the torque application based on real-time vehicle dynamics
2Duration of action of moving object
If the input torque is increased by a predetermined constant amount to raise the input speed, then the coasting shift-down action completes in reasonable time, but the input speed rises excessively rapidly when the rate of change of vehicle running speed is relatively low, causing synchronizing shock
Solution Approach 1:
The system dynamically adjusts the torque increase amount based on the rate of change of vehicle running speed. When the rate of change is low, the torque increase amount is reduced to prevent excessive rapid rise in input speed, thereby avoiding synchronizing shock while still completing the shift action within reasonable time
Solution Approach 2:
The patent changes the torque increase amount parameter based on the rate of change of vehicle running speed. By making this parameter variable rather than constant, the system can optimize the balance between shift completion time and synchronizing shock prevention for different driving conditions
Data Source
AI summary
A control apparatus for a vehicle having a step-variable transmission. The control apparatus includes: a shift control portion to temporarily increase an input torque of the step-variable transmission beyond a required value, the shift control portion commanding an engaging-side coupling device which is the coupling device placed in a released state, to be brought into an engaged state, when the input speed has been raised to a predetermined value; and a torque increasing amount setting portion to set an amount of increase of the input torque of the step-variable transmission beyond the required value, such that the amount of increase is smaller when a rate of change of a running speed of the vehicle is relatively low than when the rate of change is relatively high, the rate of change of the running speed having a negative value in a decelerating state of the vehicle.