Variable Speed Wiper System for Motor Vehicle Visibility
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Solution Overview
Problem
Modern windshield wiper systems face challenges in maintaining clear visibility during heavy rain without increasing wear or noise, especially with reversible motors, as higher wiping frequencies lead to increased dynamic load and temperature issues, contradicting customer demands for quieter and more durable systems.
Innovation Solution
A linear wiper system with a time-dependent wiping speed, where the wiper moves slower through the driver's field of vision and faster through the remaining field, optimizing availability and reducing waiting time without increasing wiping frequency, and incorporating an optional holding time in the upper reversal position to harmonize the process.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If the wiping frequency is increased to maintain clear visibility during heavy rain, then the driver's field of vision remains clearer for longer, but the dynamic load on the wiping system increases and wear on bearing points increases
Solution Approach 1:
The patent applies dynamics by making the wiping speed variable rather than constant. The control device adjusts the wiping speed dynamically: higher speeds in non-critical areas and lower speeds in the driver's direct field of vision. This dynamic speed adjustment allows the system to maintain effective clearing performance while reducing the overall dynamic load and wear on bearing points compared to uniformly high-speed operation.
Solution Approach 2:
The patent implements local quality by applying different wiping speeds to different spatial zones of the windshield. The driver's direct field of vision receives optimized attention with appropriate speed control, while other areas use higher speeds. This localized differentiation maintains visibility where needed without subjecting the entire system to the high dynamic loads that would result from uniformly high-speed operation across all areas.
2Productivity
If the wiping frequency is increased to maintain clear visibility during heavy rain, then the driver's field of vision remains clearer for longer, but the noise level increases due to quicker turning positions
Solution Approach 1:
The control device dynamically adjusts wiping speed to minimize noise while maintaining effectiveness. By using lower speeds in the driver's direct field of vision and higher speeds in other areas, the system reduces the frequency and intensity of rapid turning motions that generate noise, thereby lowering overall noise levels while still maintaining clear visibility where the driver needs it most.
Solution Approach 2:
The patent applies local quality by differentiating noise control strategies for different windshield zones. Areas critical for driver visibility receive optimized speed control that balances clearing effectiveness with noise reduction, while non-critical areas use higher speeds that generate more noise but are less problematic for driver comfort. This localized approach reduces overall noise levels compared to uniformly high-speed operation.
3Productivity
If the wiping frequency is increased to maintain clear visibility during heavy rain, then the driver's field of vision remains clearer for longer, but the temperature development of the reversible motor becomes unacceptably high
Solution Approach 1:
The control device dynamically modulates the wiping speed to reduce motor temperature. By using variable speeds with lower velocities in the driver's direct field of vision and higher velocities elsewhere, the system reduces the overall energy consumption and heat generation of the reversible motor compared to sustained high-frequency operation, while still maintaining effective clearing performance.
Solution Approach 2:
The patent implements local quality by applying differentiated speed control to different windshield zones. This reduces the total work and energy consumption of the motor by optimizing speed based on local visibility requirements, thereby reducing temperature development in the reversible motor while maintaining clear visibility in critical driver areas.
4Productivity
If the wiping frequency is increased to maintain clear visibility during heavy rain, then the driver's field of vision remains clearer for longer, but a harmonious wiping process cannot be achieved due to frequent reversing
Solution Approach 1:
The control device uses dynamic speed adjustment to achieve a harmonious wiping process. By varying the speed according to position and priority areas, the system smooths out the wiping motion and reduces the disruptive effects of frequent reversing. The dynamic control ensures that transitions between directions are more gradual and coordinated, maintaining a harmonious process even at higher overall wiping frequencies.
Data Source
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AI summary
Disclosed is a windshield wiping system in which a sinusoidal wiping curve of the wiping velocity can be predefined. In order to improve the availability of a wiper, a wiping curve v(t) whose peaks are closer to the lower reversing position than to the upper reversing position can be predefined at least for the wiper located on the driver's side such that the wiper penetrates a predefined top segment (1) of the wiping range more slowly and the remaining wiping range more quickly than during a symmetrical wiping curve regarding the reversing positions while the wiping frequency remains the same at the most.