Inductive position or angle measurement device

Abstract

The invention relates to an inductive position measuring device or goniometer having two to no more than five digital oscillators, each of which contains measuring coils or reference coils. Particularly favorable for one application as a transmission sensor is a coil array for three or four oscillators that includes two measuring coils and / or two reference coils. When one plate-shaped measuring element that is sensitive for eddy currents passes through the measuring area, a measuring coil arranged in a planar manner is increasingly covered. One reference coil is arranged such that it does not touch the movement track of the measuring element, but is exposed to the same ambient conditions (temperatures) as the measuring coil. Another reference coil is arranged such that it is covered by the measuring element in the entire measuring area and therefore can compensate the fluctuations in the spacing height between the planar coil array and the measuring element that occur during operation. It is also possible to use additional height reference coils to compensate tilting of the measuring element. Pulse frequencies of the digital oscillator signals are counted asynchronously and subtracted by pairs in a digital evaluation circuit. The operation of the evaluation circuit has the aid of a clock signal provided by a system frequency, the clock signal is derivate directly or through a digital frequency divider from a pulse frequency of a fiducial oscillator.

Description

technical field [0001] The invention relates to an inductive position- or angle-measuring device with two, three or four digital oscillators, which always contain a measuring coil or a reference coil. The measuring or reference coils are arranged in a coil row, near which the moving measuring element assumes a defined position or a defined angle. The measuring element can belong, for example, to a transmission sensor mounted on the vehicle transmission. In this application, the measuring cell is mechanically connected to the gear selection control inside the gearbox. The gear selection control device can in particular be a gearshift rocker of a double clutch transmission. The measuring element can be adapted to a linear movement of the control device or to a circular movement such as that of a selector rocker. In the second case, the measuring element, which is introduced into a circular coil row, is bent correspondingly to the direction of movement. Position-sensing measu...

AI Technical Summary

Problems solved by technology

In addition, because inductive sensing technology needs to solve the measurement of multiple intermediate positions or multiple angular positions along the motion track of the gear selection-control device, the fourth problem is that the characteristic curve of the sensor needs to be in a relatively large measurement range. is linear

The last fifth question is that metal sludge accumulated due to friction in the gearbox oil sump should not affect the measurement (for example, when using a Hall sensor, its permanent magnet will be surrounded by iron filings as the working time increases )

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