Wiper Control Unit Speed Transition Mechanism
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Solution Overview
Problem
Existing wiper systems experience uncomfortable and jerky transitions when switching between high speed and low speed modes due to rapid changes in wiper motor rotational speed, leading to temporary hitching and discomfort for the driver.
Innovation Solution
A wiper system with an electric motor and control unit that gradually changes the wiper's moving speed over a predetermined number of swings between upper and lower return positions when switching operational modes, ensuring a smoother transition by matching the preset speed of the new mode during this period.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Speed
If the rotational speed of the wiper motor is rapidly changed when switching operational modes, then the response time to mode change is improved, but the smoothness of wiper operation deteriorates causing temporary hitching and driver discomfort
Solution Approach 1:
The patent applies dynamics by making the wiper motor's rotational speed adjustable and variable during operation. The control unit dynamically changes the rotational speed from the first operational mode to the second operational mode gradually, rather than making an abrupt switch. This dynamic adjustment allows the system to adapt to different operational requirements while maintaining smooth operation and avoiding temporary hitching that would occur with rapid speed changes.
2Ease of operation
If the wiper motor rotational speed is progressively changed during mode transition, then the smoothness of operation is improved, but the response time to mode change increases
Solution Approach 1:
The patent applies parameter changes by systematically varying the rotational speed parameter of the wiper motor during mode transition. The control unit changes the rotational speed from the first operational mode to the second operational mode through intermediate speed values, creating a progressive transition. This parameter change approach balances smoothness of operation with reasonable transition time, avoiding both abrupt changes that cause hitching and excessively gradual changes that would take too long.
Data Source
AI summary
A wiper is pivotably supported and is swung by a drive force of an electric motor. When a command, which commands execution of one of high and low speed modes, is entered through a wiper switch in the middle of operation of the wiper in another one of the high and low speed modes, a control unit controls an electric motor such that a moving speed of the wiper, which is preset for the another one of the high and low speed modes, is changed to the moving speed of the wiper, which is preset for the one of the high and low speed modes, during a time period of executing a predetermined number of swings of the wiper between an upper return position and a lower return position upon entering of the command through the wiper switch means.