Counting sensor having a correction function

Patent metadata

Field	Value
Publication number	US-10330501-B2
Application number	US-201715609439-A
Country	US
Kind code	B2
Filing date	May 31, 2017
Priority date	May 31, 2016
Publication date	Jun 25, 2019
Grant date	Jun 25, 2019

Abstract

The invention relates to a counting sensor for counting the number of rotations or of linear displacements of an object, wherein the counting sensor comprises:
one single Wiegand module; at least one sensor element; a processing electronic circuit, which is connected to the sensor element; and a permanent magnet arrangement, which is movable relatively to the Wiegand module; wherein the processing electronic circuit is configured to obtain direction information, whether the permanent magnet arrangement moves in said one direction or in an opposite direction, and (ii) to obtain magnetic pole information; and a data storage for storing a value, which indicates the number of the rotations or of the linear displacements; wherein: the processing electronic circuit is configured (i) to determine, on the basis of the direction information and the magnetic pole information, the number of the rotations or of the linear displacements of the object and to store the corresponding value in the data storage, (ii) to perform, on the basis of a sequence of the direction informations and of the magnetic pole informations, an error detection to the effect whether one of the rotations or one of the linear displacements of the object has not been recognized partially or completely, and (iii) to determine an according correction and to correct the value upon detection of an error.

First claim

The invention claimed is:

1. Counting sensor for counting the number of rotations or linear displacements of an object, wherein the counting sensor has the following:
one single Wiegand module, which is composed of a Wiegand wire having a coil surrounding the Wiegand wire;
at least one sensor element;
a processing electronic circuit, which is connected to the sensor element, and which is configured to evaluate an output signal that is output from the sensor element; and
a permanent magnet arrangement, which is movable relatively to the Wiegand module in one direction as well as in a direction that is opposite to said one direction, wherein the permanent magnet arrangement is configured to be arranged at the object such that the permanent magnet arrangement effects the rotations or linear displacements together with the object; wherein:
upon movement of the permanent magnet arrangement in said one direction, the coil of the Wiegand module generates a voltage impulse, if a north pole or a south pole of the permanent magnet arrangement is located at a first position, and, upon movement of the permanent magnet arrangement in said opposite direction, the coil of the Wiegand module generates a voltage impulse, if the north pole or the south pole of the permanent magnet arrangement is located at a second position that is different from the first position,
in an autonomous mode, in which the counting sensor is not supplied with outside energy, the processing electronic circuit is supplied with energy, which is provided by the Wiegand module,
the processing electronic circuit is configured, after detecting the voltage impulse output from the Wiegand module
(i) to obtain direction information about whether the permanent magnet arrangement moves in said one direction or in said opposite direction by the evaluation of the output signal of the sensor element, and
(ii) to obtain magnetic pole information about whether the north pole or the south pole of the permanent magnet arrangement is located at the first or the second position by the evaluation of the output signal of the sensor element or by the determination of the polarity of the voltage impulse generated by the coil of the Wiegand module;
a data storage for storing a value, which indicates the number of the rotations or of the linear displacements; and
a tracking information storage for storing tracking information, which indicates whether the south pole or the north pole of the permanent magnet arrangement has come to pass a particular tracking position or not, wherein the north pole or the south pole is located at the tracking position, if a magnetic field, which corresponds to the north pole or to the south pole, is oriented parallel to the Wiegand wire and acts maximally on the magnetic domains of the Wiegand wire; wherein:
the processing electronic circuit is configured
(i) to incorporate both the direction informations and also the magnetic pole informations in a sequence, to determine the number of the rotations or of the linear displacements of the object on the basis of the direction informations and the magnetic pole informations, and to store the corresponding value [of said number] in the data storage, and
(ii) to perform, on the basis of said sequence and the tracking information, an error detection to the effect whether one of the turns or one of the linear displacements of the object has not been recognized partially or completely, and
(iii) to determine a corresponding correction of said number and to correct said value upon detection of an error.

2. Counting sensor according to claim 1 , wherein
if, in said sequence, consecutive direction informations and consecutive magnetic pole informations are identical, the error detection provides a result to the effect that an error is present, and the correction is determined as a function of the tracking information such that
a. if the tracking information indicates that the magnetic pole, which is contained in the magnetic pole informations, has come to pass the tracking position in time between the receipt of the identical direction and magnetic pole informations, the value in the data storage is supplemented, and
b. if the tracking information indicates that the magnetic pole, which is contained in the magnetic pole information, has not come to pass the tracking position in time between the receipt of the identical direction and magnetic pole informations, the value in the data storage is not changed.

3. Counting sensor according to claim 2 , wherein
the tracking storage is arranged at the tracking position and is a magnetic field-sensitive storage, which is writable by the north and the south pole, which is erased upon the generation of the voltage impulse and which is subsequently written into the tracking information exclusively by the first pole of the permanent magnet arrangement, which comes to pass the tracking storage.

4. Counting sensor according to claim 3 , wherein the processing electronic circuit is configured, upon the generation of the voltage impulse, to read out the tracking information from the tracking storage before the tracking information is erased.

5. Counting sensor according to claim 1 , wherein
the processing electronic circuit is configured
to store the magnetic pole information, if the voltage impulse, which is generated by the Wiegand module, exceeds a medium voltage threshold, wherein the precedingly stored magnetic pole information is transferred beforehand to the tracking storage and serves as the tracking information, if the voltage impulse, which is generated by the Wiegand module, exceeds a lower voltage threshold, which is below the medium voltage threshold, and
to determine, on the basis of the direction information and the magnetic pole information, the number of rotations or of the linear displacements of the object, and to store the corresponding value in the data storage, if the voltage impulse, which is generated by the Wiegand module, exceeds an upper voltage threshold, which is above the medium voltage threshold.

6. Counting sensor according to claim 1 , wherein
the counting sensor further has a magnetic field-sensitive temporary storage, which is written directly by the north pole or by the south pole of the permanent magnet arrangement, and which stores magnetic pole data, which indicate whether the temporary storage has been written into by the north pole or by the south pole; and
the processing electronic circuit is configured,
to read out the magnetic pole data from the temporary storage and to transfer [them] into the tracking storage, if the voltage impulse, which is generated by the Wiegand module, exceeds a lower voltage threshold, and subsequently to allow an overwriting of the data in the magnetic field-sensitive temporary storage, and
to determine, on the basis of the direction information and the magnetic pole information, the number of the rotations or of the linear displacements of the object, and to store the corresponding value in the data storage, if the voltage impulse, which is generated by the Wiegand module, exceeds an upper voltage threshold, which is above the lower voltage threshold.

7. Counting sensor according to claim 1 , wherein
if, in said sequence, consecutive direction informations are identical and consecutive magnetic pole informations are different, the error detection provides a result to the effect that no error is present, and the number of the rotations or of the linear displacements of the object is determined correspondingly, and the corresponding value is stored in the data storage.

8. Counting sensor according to claim 1 , wherein
if, in said sequence, consecutive direction informations and consecutive magnetic pole informations are diffe

Assignees

• Avago Tech Int Sales Pte Lid

Inventors

• Mehnert Walter
• Theil Thomas

Classifications

• G01D5/24476 Primary

  Signal processing (G01D5/2448 - G01D5/24495 take precedence) · CPC title

• G01D5/145

  influenced by the relative movement between the Hall device and magnetic fields (see G01R33/06) · CPC title

• G01P3/4815

  using a pulse wire sensor, e.g. Wiegand wire · CPC title

• G01D5/245

  using a variable number of pulses in a train · CPC title