Wiper Motor Control Sinusoidal Speed Profile
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Solution Overview
Problem
Existing wiper systems face challenges in maintaining effective wiping at low frequencies without causing noise pollution, premature wear, or rattling, especially when the wiper arm speed is reduced between turning positions.
Innovation Solution
A wiper motor controller that adjusts the speed of the wiper arm based on its position, following a sinusoidal profile in turning areas to minimize mechanical stress and prevent rattling, while maintaining a low wiping frequency, and is dependent on the mechanical load of the wiper motor.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If the speed of the wiper arm is reduced between turning positions to achieve low wiping frequency, then energy consumption is reduced and wiping frequency is lowered, but the wiper blade may rattle or chatter causing noise pollution and premature wear
Solution Approach 1:
The patent applies dynamics by making the wiper arm speed variable rather than constant. The speed profile is dynamically adjusted based on the wiper arm position, being reduced between turning positions and increased in turning areas. This dynamic speed variation allows the system to achieve low average wiping frequency while preventing rattling by maintaining sufficient speed in critical turning regions.
Solution Approach 2:
The patent changes the speed parameter as a function of position. The speed profile follows a sinusoidal pattern where the speed parameter varies continuously throughout the wiping cycle. This parameter change ensures that the wiper arm moves slowly between turning positions (reducing wear and energy consumption) but maintains adequate speed during turning areas (preventing rattling and noise).
2Stress or pressure
If the speed of the wiper arm is reduced between turning positions to minimize mechanical stress, then mechanical stress is reduced, but the wiper blade may chatter or rattle
Solution Approach 1:
The patent applies local quality by applying different speed characteristics to different spatial regions of the wiping cycle. Specifically, the speed profile is locally optimized: reduced speed is applied in non-turning areas where low mechanical stress is beneficial, while higher speed is applied in turning areas where sufficient momentum is needed to prevent chattering and rattling.
Solution Approach 2:
The patent implements periodic action through the sinusoidal speed profile that repeats with each wiping cycle. This periodic variation in speed creates a rhythmic motion pattern that naturally reduces mechanical stress during the low-speed portions while ensuring adequate speed during turning portions, preventing chattering and rattling through the periodic acceleration and deceleration pattern.
Data Source
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AI summary
The invention relates to a wiper motor control for controlling a wiper motor that moves a wiper arm in a pendulum motion between two turning positions, said wiper motor control being designed to control a speed of the wiper arm dependent on a position of the wiper arm. The speed of the wiper arm in turning regions, which comprise the turning positions, follows a specified progression independent of the speed of the wiper arm between the turning regions.