Position sensor
First Claim
1. A method for magnetostrictive position determination of a magnetic position indicator (3), along a wave conductor (2), through measurement of a sum (100) of run times of a voltage impulse and of a mechanical-elastic wave (10) resulting there from, wherein the run time sum is determined through:
- providing a system timing (110);
starting the voltage impulse (start impulse 101) in a fixed phase relationship at the beginning of a period (111) of the system timing (110);
determining a coarse time value of a coarse time interval (104) through digital determination of an integer number of periods (111) of the system timing (110), which is correlated in a defined manner with the run time sum (100);
analog determination of a fine time value of a supplemental time interval between arrival of the mechanical-elastic wave (stop impulse 102) and the start of a defined period of the coarse time interval (104);
digitizing the fine time value; and
computing the coarse time value with the fine time value into the run-time sum.
1 Assignment
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Accused Products
Abstract
In order to be able to perform a measurement of the run time of an electrical impulse in a position sensor through a single slow timed timing generator, while still capable to achieve a high precision of the measurement result, the entire run time is determined, so that the number of the completely performed system timings is counted as a coarse time value, and the fractions thereof are counted as a fine time value, in which the electrical impulse is started at a fixed point in time of the system timing, e.g. at the beginning of the timing, and the difference value is measured between the end of the coarse time interval and the arrival of the wave as a fine time interval, which is then digitized and computed with the coarse time value.
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Citations
18 Claims
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1. A method for magnetostrictive position determination of a magnetic position indicator (3), along a wave conductor (2), through measurement of a sum (100) of run times of a voltage impulse and of a mechanical-elastic wave (10) resulting there from, wherein the run time sum is determined through:
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providing a system timing (110); starting the voltage impulse (start impulse 101) in a fixed phase relationship at the beginning of a period (111) of the system timing (110); determining a coarse time value of a coarse time interval (104) through digital determination of an integer number of periods (111) of the system timing (110), which is correlated in a defined manner with the run time sum (100); analog determination of a fine time value of a supplemental time interval between arrival of the mechanical-elastic wave (stop impulse 102) and the start of a defined period of the coarse time interval (104); digitizing the fine time value; and computing the coarse time value with the fine time value into the run-time sum. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17)
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18. A magnetostrictive position sensor (1), said sensor comprising:
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a wave conductor (2); a magnetic position indicator (3), movable along the wave conductor (2); signal electronics (5) at a measurement location at one end of the wave conductor (2); wherein the signal electronics (5) include an excitation circuit (6) and a system timing clock (7); and only one interpolator for fine determination next to the coarse counter (9).
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Specification