Vehicular Variator Control for Instantaneous Interruption Recovery
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Solution Overview
Problem
Conventional techniques for controlling vehicular variators during instantaneous interruptions result in prolonged engine rotation speed increases due to slow convergence of transmission ratios, leading to unnecessary high engine rotation speeds during power reset.
Innovation Solution
A vehicular variator control device that sets the target transmission ratio to a higher change speed from the lowest transmission ratio value during power reset, allowing quicker convergence to the desired transmission ratio, thereby preventing unnecessary engine rotation speed increases.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If the target transmission ratio is set to the lowest transmission ratio value by initialization processing after power reset, then the variator transmission ratio can be adjusted to match the desired transmission ratio, but the convergence time becomes excessively long causing unnecessary engine rotation speed increase
Solution Approach 1:
The patent applies dynamics by making the target transmission ratio change speed adaptive rather than fixed. The control device dynamically adjusts the change speed based on whether the system is in normal control or instantaneous interruption recovery control mode. During recovery control, the target transmission ratio converges to the desired value at a higher speed, reducing convergence time and preventing excessive engine rotation speed increase while ensuring reliable transmission ratio adjustment.
Solution Approach 2:
The patent changes the parameter of target transmission ratio change speed from a fixed value to a variable parameter. By switching between normal control (lower change speed) and instantaneous interruption recovery control (higher change speed), the system optimizes the convergence process. This parameter change allows the variator to quickly recover from the lowest transmission ratio value to the desired transmission ratio, resolving the contradiction between reliable convergence and excessive convergence time.
2Device complexity
If the target transmission ratio changes at the same speed as under normal control after power reset, then the control process remains simple, but the engine rotation speed becomes unnecessarily high due to prolonged downshift duration
Solution Approach 1:
The control device dynamically adjusts the target transmission ratio change speed based on the operational mode. During instantaneous interruption recovery control, the system uses a higher change speed to quickly converge the transmission ratio, reducing the duration of high engine rotation speed. This dynamic adjustment resolves the contradiction by making the control process adaptive rather than static, preventing excessive energy consumption while maintaining reasonable complexity through mode-based switching.
3Manufacturing precision
If the variator transmission ratio is adjusted from the lowest transmission ratio value to the desired transmission ratio value, then the transmission ratio convergence is achieved, but the input rotation speed of the transmission is set high for a long duration
Solution Approach 1:
The patent changes the parameter of target transmission ratio change speed to resolve the contradiction between transmission ratio accuracy and downshift duration. By using a higher change speed during instantaneous interruption recovery control, the system achieves the required transmission ratio accuracy in a shorter time, preventing prolonged high input rotation speed while ensuring the variator reaches the desired transmission ratio value.
Data Source
AI summary
Provided are a variator and a transmission controller in an engine-driven vehicle. The transmission controller has an instantaneous interruption recovery control portion configured to, upon a power reset from an instantaneous interruption during running, set a target through transmission ratio and a desired through transmission ratio to a lowest transmission ratio value by initialization and perform recovery control to recover an actual through transmission ratio of the variator to a transmission ratio value for shifting to normal control. The instantaneous interruption recovery control portion is further configured to, upon the power reset from the instantaneous interruption during the running, set a change speed of the target through transmission ratio from the lowest transmission ratio value to the desired through transmission ratio, to be higher than that under the normal control, before a time at which the desired through transmission ratio value deviates from the lowest transmission ratio value.