Electrostatic Applicator Distance Measurement via Capacitance
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Solution Overview
Problem
In painting and welding applications, existing methods require additional sensors to measure distances accurately, which add complexity, cost, and vulnerability, especially when dealing with high-voltage equipment and conductive paints, and there is a need for a simpler way to correct deviations in position without additional equipment.
Innovation Solution
Measuring the voltage and saturation current between an electrostatic applicator and an object, determining the onset voltage for ionization, and calculating the distance based on these measurements, allowing for proximity sensing and position correction without additional sensors.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If additional sensors (cameras, radar, IR-sensors) are used to measure distance and correct position, then measurement precision is improved, but device complexity increases and reliability decreases due to vulnerability and paint interference
Solution Approach 1:
The electrostatic applicator is made to serve dual functions: applying conductive paint/coating and measuring distance to the substrate. By utilizing the applicator's existing electrical components (electrodes, high-voltage generator) for both painting and sensing, the patent eliminates the need for separate distance measurement sensors, thereby reducing device complexity while maintaining measurement capability
Solution Approach 2:
The system uses its own inherent electrical properties (capacitance changes in the electrostatic field) for distance measurement rather than relying on external sensors. The applicator's electrical system serves itself to detect distance by measuring changes in electrical parameters, eliminating dependency on additional measurement equipment
2Measurement precision
If additional sensors are mounted near the spray head for distance measurement, then measurement precision is improved, but reliability worsens due to paint collection on sensors and high-voltage interference
Solution Approach 1:
The electrostatic applicator measures distance using its own electrical field and capacitance changes, eliminating the need for separate sensors that would be vulnerable to paint contamination and high-voltage interference. The measurement function is integrated into the applicator's existing electrical system
Solution Approach 2:
The patent uses electrical field parameters (capacitance, voltage, current) as an intermediary medium to measure distance indirectly without physical contact between the measurement device and the environment. This electrical field mediation allows distance sensing without exposing sensitive components to paint spray and high-voltage conditions
3Device complexity
If the electrostatic applicator is used directly for distance measurement, then device complexity is reduced, but measurement precision must be maintained through accurate electrical parameter measurement
Solution Approach 1:
The patent replaces mechanical/optical sensing systems with an electrical field-based measurement system. By substituting physical sensors with electrical parameter measurement (capacitance, voltage, current), the system achieves simplified structure while maintaining measurement capability through electrical field interactions between the applicator and substrate
Solution Approach 2:
The system measures distance by detecting changes in electrical parameters (capacitance, voltage, current) of the electrostatic field as the distance between the applicator and substrate varies. This parameter-based measurement approach enables accurate distance detection through electrical characteristics rather than mechanical or optical means
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
Enables accurate distance measurement and position correction in painting and welding processes without the need for additional sensors, reducing complexity and cost, and providing a robust solution against paint interference and high-voltage challenges.
Implementation Method 1
The atomizer comprises a central spray head and a number of electrode holders arranged in a concentric ring around the spray head. The electrode holders include high-voltage generators. The function of the atomizer is that the droplets from the spray head are charged in the electric field formed between the high-voltage electrodes and the grounded spray head
Implementation Method 2
the charged paint particles are accelerated towards the surface, where they adhere
Implementation Method 3
measuring the voltage and saturation current between an electrostatic applicator and an object, determining the onset voltage for ionization, and calculating the distance based on these measurements
Data Source
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AI summary
The present invention relates to a method for measuring the distance to an object to be worked on by a work tool, wherein the method comprises the steps of applying a voltage field to the work tool, measuring the current between the work tool and the object, comparing the current with a predefined value, which value is based on a predetermined distance between the work tool and the object, and indicating if the measured current exceeds the predefined value, which provides information that the object is within a certain distance from the work tool. The method further comprises, when the work tool is an electrostatic paint applicator, the steps of measuring the voltage of the electrostatic applicator, measuring the saturation current between the applicator and the object, determining the onset voltage where the ionization begins, which voltage is dependent on the distance to the object, calculating the actual distance to the object based on the measured voltage and current taking into account the distance dependent onset voltage. The present invention also relates to a device and a computer program product for performing the method.