Inductive Sensor Motor Time Estimation
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Solution Overview
Problem
Existing methods using inductive sensors to measure the operating time of endothermic motors in landscaping tools are limited in accuracy due to overlapping electromagnetic variations from the sparking spark and the rotation of the motor's free wheel, making it difficult to calculate rotating speeds.
Innovation Solution
A method that involves cyclically measuring time intervals between variation peaks of the electromagnetic field, obtaining frequencies, and using pre-set ranges of frequencies to calculate representative rotation frequencies, while accounting for corrective coefficients based on the number of peaks and their least common multiples.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Use of energy by moving object
If an inductive sensor is used to measure electromagnetic field variations, then energy consumption is reduced, but measurement precision deteriorates due to overlapping signals from free wheel magnets and sparking spark
Solution Approach 1:
The patent segments the electromagnetic field variations into distinct components by analyzing the temporal pattern of peaks. It identifies and separates the sparking spark signal (occurring at specific intervals corresponding to combustion events) from the free wheel magnet signal (occurring at regular intervals corresponding to magnet rotation). This segmentation allows the system to extract accurate rotation speed information despite the overlapping nature of the signals.
Solution Approach 2:
The patent applies preliminary action by pre-defining frequency ranges corresponding to different operating conditions (idling, maximum running, intermediate speeds) before actual measurement. These pre-set ranges are used to classify and interpret the measured frequencies, enabling the system to accurately determine operating conditions without requiring complex real-time analysis of overlapping signals.
2Ease of operation
If the inductive sensor position is fixed due to tool shape constraints, then ease of operation is improved, but measurement precision deteriorates because the sensor cannot be optimally positioned to avoid free wheel magnet interference
Solution Approach 1:
The patent changes the parameter being measured from the raw electromagnetic field intensity to the temporal pattern and frequency characteristics of the signal. By analyzing the time intervals between peaks and the frequency distribution, the system can distinguish between sparking spark and free wheel magnet signals regardless of the sensor's fixed position. This parameter transformation enables accurate measurement without requiring optimal sensor positioning.
3Device complexity
If simple peak counting is used to determine rotation speed, then device complexity is reduced, but measurement precision deteriorates because it cannot distinguish between overlapping electromagnetic variations
Solution Approach 1:
The patent implements feedback by using the measured frequency information to identify the operating condition (idling, maximum speed, or intermediate speed) and then applying appropriate corrective coefficients. The system continuously monitors the frequency of electromagnetic variations and adjusts its interpretation based on the detected operating regime, enabling accurate rotation speed determination through a relatively simple counting mechanism enhanced by feedback-based classification.
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
This method provides an accurate estimate of the operating time at specific rotating speeds, improving the accuracy of wear monitoring in landscaping tools by effectively distinguishing between different operating conditions.
Implementation Method 1
an inductive sensor for taking such measurement of the operating hours... allows measuring the variations in electromagnetic field generated from the passage of the current required to generate a spark in the combustion chamber of the endothermic motor and/or from the magnets present in the free wheel of the endothermic motor
Data Source
AI summary
A method is described for estimating, by measurements taken by an inductive sensor, the time for which an endothermic motor of a tool has operated at predetermined rotating speeds, and an apparatus implementing the method also described. The method in particular includes cyclically measuring, at a pre-set sampling period, an overall time interval by starting at the beginning of the measuring of the overall time interval when a first variation peak of the electromagnetic field is sensed and terminating the measuring of the overall time interval when a last variation peak of the electromagnetic field is sensed. The first and the last peaks are the start and tail ends of a sequence of peaks having a predetermined number of successive peaks, the number of peaks being positive, whole, at least equal to six and a least common multiple of two and three.