Linear Scale Sensor Phase Alignment for Extended Stroke Measurement
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Solution Overview
Problem
Existing systems for determining the distance from a reference point in elongate moving-magnet type linear motors are costly and inaccurate due to the complexity of synthesizing signals from multiple detection elements over a stroke range greater than the scale length.
Innovation Solution
A linear scale with a scale element having magnetic bodies of alternating polarities and sensors arranged at even intervals to output waveform signals of the same phase, allowing for continuous detection and synthesis of signals to determine distance from a reference point without a massive circuit configuration.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Length of stationary object
If a plurality of detection elements are arranged over a stroke range greater than the scale length with flip-flop circuits and latching mechanisms, then the measurement range is extended, but the device complexity and cost increase significantly
Solution Approach 1:
The invention extracts and eliminates the complex flip-flop circuits, latching mechanisms, and signal synthesis hardware from the detection system. By using a single detection element that continuously outputs analog waveform signals, the patent removes the need for switching mechanisms and signal synthesis circuits, thereby extending the measurement range while reducing device complexity.
Solution Approach 2:
The patent replaces the mechanical/electronic switching system (flip-flop circuits and latching mechanisms) with a continuous analog waveform signal system. The detection element continuously outputs sinusoidal or triangular waveform signals that directly represent position information, eliminating the need for digital switching and synthesis hardware.
2Measurement precision
If flip-flop circuits and latching mechanisms are used to determine which detection element reads the scale element, then the position detection is achieved, but the manufacturing cost increases
Solution Approach 1:
The invention replaces expensive, complex flip-flop circuits and latching mechanisms with a simple, continuous analog waveform signal system. The single detection element continuously outputs waveform signals that can be directly processed to determine position, eliminating the need for costly switching and synthesis hardware while maintaining measurement precision.
Solution Approach 2:
The patent extracts and removes the expensive flip-flop circuits and latching mechanisms from the system. By using a detection element that continuously outputs analog waveform signals, the invention eliminates the need for complex signal switching and synthesis hardware, thereby reducing manufacturing cost while maintaining position detection accuracy.
3Length of stationary object
If multiple detection elements with latching mechanisms are used, then the stroke range coverage is improved, but the signal synthesis accuracy deteriorates
Solution Approach 1:
The invention implements continuous detection by using a single detection element that continuously outputs analog waveform signals across the entire stroke range. This continuous signal output eliminates the discontinuities and synthesis errors that occur when switching between multiple detection elements, thereby improving signal synthesis accuracy while maintaining extended stroke range coverage.
Solution Approach 2:
The patent merges the functions of multiple detection elements into a single detection element that continuously outputs waveform signals across the entire stroke range. This unified approach eliminates the need for signal synthesis from multiple elements, thereby improving signal synthesis accuracy while maintaining extended stroke range coverage.
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 from a reference point over a stroke range greater than the scale length at a lower cost by synthesizing waveform signals of the same phase, reducing the need for complex flip-flop circuits and enhancing signal accuracy.
Implementation Method 1
a scale detection mechanism which outputs waveform signals of the same phase and are corresponding to a magnetic flux density generated by the magnetic bodies of the scale element
Implementation Method 2
an elongate moving-magnet type linear motor... a magnetic body mounted to the movable section
Data Source
AI summary
Disclosed is a linear scale for obtaining a distance from a reference point. A scale detection mechanism is adapted to output waveform signals of the same phase. Also the scale detection mechanism corresponds to a magnetic flux density generated by magnetic bodies of a scale element. The scale detection mechanism may be sensors. The sensors are arranged at even intervals corresponding to a scale length of the scale element. The sensors are adapted to output sine-wave signals having the same phase to continuously detect the scale element in a movement direction of the scale element. The scale element has opposite ends each has the same polarity and configured such that an output voltage of the single sensor detecting the end of the scale element is reduced to one-half of an output voltage of the single sensor detecting the remaining portion of the scale element.