JP2004205456A - Counter for incremental encoder - Google Patents

Counter for incremental encoder Download PDF

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Publication number
JP2004205456A
JP2004205456A JP2002377900A JP2002377900A JP2004205456A JP 2004205456 A JP2004205456 A JP 2004205456A JP 2002377900 A JP2002377900 A JP 2002377900A JP 2002377900 A JP2002377900 A JP 2002377900A JP 2004205456 A JP2004205456 A JP 2004205456A
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Prior art keywords
sampling
counting
magnetic
periodic signal
cycle
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JP2002377900A
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JP4074188B2 (en
Inventor
Satoshi Adachi
聡 安達
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Mitsutoyo Corp
株式会社ミツトヨ
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Abstract

Provided is a counting device for an electromagnetic induction type incremental encoder, which can perform an intermittent operation as appropriate while securing a sufficient moving speed of a movable portion, thereby suppressing an increase in power consumption. Periodic signals having a phase difference of 120 degrees output from the magnetic flux sensors 124, 126, and 128 are sampled by the sample and hold circuits 141 to 143 at a sampling period Ts. The wave number counting unit 165 counts the wave number Nw of the periodic signal based on the sampling result. On the other hand, the storage unit 164 stores the result of further sampling the sampling result of the sample and hold circuits 141 to 143 at a timing in consideration of the display update cycle of the display unit 300. Based on the sampling data stored in the storage unit 164, the relative movement amount of the two members within one wavelength λ of the periodic signal is calculated by the one-wavelength movement amount calculation unit 166. The step is executed in a time-sharing manner based on the sampling period Ts.
[Selection diagram] FIG.

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a counting device for an incremental encoder of an electromagnetic induction type, a capacitance type or the like.
[0002]
[Prior art]
There are two types of encoders for measuring the relative movement amount of two members, an incremental (INC) type and an absolute (ABS) type, depending on the form of the output signal. In the case of the electromagnetic induction type, the INC type, for example, as shown in Patent Document 1, samples a periodic signal (induced current) generated by the movement of a movable portion (read head or the like) at a predetermined sampling cycle, and obtains a sampling result. Is used to measure the relative displacement of the movable part. On the other hand, the ABS type demodulates periodic signals obtained from a plurality of scales having different pitches, obtains phase information corresponding to the absolute position from each demodulated signal, and detects the absolute position of the movable element based on the phase information. It is possible.
[0003]
The ABS type measurement system has a disadvantage that the calculation processing amount is larger than that of the INC type, but can execute the calculation only by acquiring the phase information at the measurement position. For this reason, the current consumption can be reduced by performing the intermittent operation of the arithmetic control unit at a position other than the measurement position.
On the other hand, the INC type has a merit that the amount of calculation is smaller than that of the ABS type. However, the periodic signal must be sampled sequentially not only at the measurement position but also between the reference position and the measurement position. Specifically, the sampling of the periodic signal must be performed at a sampling cycle that is equal to or less than half the cycle of the periodic signal.
[0004]
[Patent Document 1]
JP-A-10-318781 (pages 8 to 10)
[0005]
[Problems to be solved by the invention]
The period of the above-mentioned periodic signal becomes shorter in inverse proportion to the speed of the movable part of the encoder. For this reason, when the speed of the movable part increases, the sampling cycle also needs to be shortened.
At this time, if the calculation of the movement amount of the movable unit is performed for each sampling result, the calculation load increases, and the calculation of the movement amount cannot be performed within the sampling cycle. This means that the upper limit of the moving speed of the unit (hereinafter referred to as the response speed) must be kept low. If the intermittent operation is performed during the movement of the movable part as in the case of the ABS type, the response speed will be much lower.
[0006]
In addition, it is possible to shorten the calculation time by using a CPU having a large operating frequency, but in this case, a new problem that the power consumption is increased arises. In the case of a hand-held digital caliper or the like, it is difficult to mount a CPU with a high operating frequency because of the life of the battery and the like.
The present invention has been made in view of the above points, and provides an incremental encoder counting device that can perform an intermittent operation as appropriate while securing a sufficient moving speed of a movable unit, thereby suppressing an increase in power consumption. The purpose is to:
[0007]
[Means for Solving the Problems]
In order to achieve the above object, a counting device for an incremental encoder according to the present invention uses a periodic signal output in accordance with a relative movement of two members arranged opposite to each other, and displays a relative movement amount of the two members in a display update cycle. And a first sampling means for sampling the periodic signal at a first sampling period shorter than the display update period, and counting a wave number of the periodic signal based on a result of the sampling. A wave number counting unit, a second sampling unit that samples the periodic signal at a second sampling period corresponding to the display update period, and a second sampling unit that performs sampling within one period of the periodic signal based on a sampling result of the second sampling unit. The amount of relative movement of the two members is determined by the second sump. And wherein further comprising a calculating means for calculating a time-division in the ring cycle for each of the first sampling period.
[0008]
The present invention focuses on the fact that the display update cycle of the display unit can be set to a sufficiently long time as compared with the sampling cycle of the periodic signal. According to the knowledge of the inventors, even if the display update cycle of the display unit is set to, for example, about 125 ms, the usability of the user does not decrease so much. On the other hand, the sampling period of the periodic signal needs to be adjusted to the response speed, and in some cases, may be several ms or less. Therefore, in the present invention, sampling is performed at the first sampling period by the first sampling unit, and the wave number of the periodic signal is counted by the wave number counting unit in accordance with the sampling period. On the other hand, the second sampling means samples the periodic signal at a second sampling period in consideration of the display update period of the display unit. Based on the sampling result, the amount of movement of the periodic signal within a range of one wavelength is calculated for each first sampling period by time division. As a result, even if the first sampling cycle is shortened, the calculation of the movement amount may be performed within the second sampling cycle that is sufficiently longer than the first sampling cycle, and the power consumption of the counting device is reduced. The requirements of both suppression and keeping the response speed high can be simultaneously satisfied.
[0009]
According to the present invention, a fluctuating magnetic field generated by a magnetic field generator installed on one of two members arranged oppositely causes an induced current to be generated on a receiving electrode installed on the other member, and the induced current is generated according to the relative movement of the two members. The present invention can be applied to a counting device of an electromagnetic induction type incremental encoder that calculates and outputs a relative movement amount of the two members in a display update cycle based on the output periodic signal. Further, in the present invention, each processing of the calculation performed in the time division is performed in a time interval during which the counting operation by the wave number counting means is not performed in the first sampling period. Is preferred. The sampling by the second sampling means may be performed at least once in the display update cycle.
[0010]
BEST MODE FOR CARRYING OUT THE INVENTION
Hereinafter, preferred embodiments of the present invention will be described with reference to the accompanying drawings. FIG. 1 and FIG. 2 are views showing a main part of an incremental type electromagnetic induction rotary encoder according to an embodiment of the present invention.
FIG. 1 shows an outline of the entire structure of the encoder, and FIG. 2 shows an excerpt of the detailed structure of each part. Although FIG. 2 is represented linearly for easy understanding, it is actually formed in an arc shape as shown in FIG.
[0011]
As shown in FIG. 1, an incremental type electromagnetic induction type rotary encoder 1 of the present embodiment is disposed opposite to a read head 100 which is a first member that rotates in a direction of a measurement axis 114, with a predetermined gap therebetween. And a scale 200 as a second member.
A magnetic field generator 111 for generating a fluctuating magnetic field is provided on the read head 100 side, and a coupling functioning as a receiving electrode for generating an induced current due to the fluctuating magnetic field generated by the magnetic field generator 111 is provided on the scale 200 side. Loops 251A and 251B are provided. Further, on the read head 100 side, there are provided magnetic flux sensors 124, 126, 128 for detecting a magnetic field generated by the induced current generated in the coupling loops 251A, 251B.
[0012]
The magnetic field generator 111 has a first magnetic field generator portion 111A and a second magnetic field generator portion 111B. The first magnetic field generator portion 111A is disposed at the outer peripheral edge of the read head 100 with the measurement axis 114 as the longitudinal direction, and the second magnetic field generator portion 111B is disposed between the first and second magnetic flux sensors 124, 126, 128. The measurement axis 114 is arranged on the opposite side to the magnetic field generator portion 111A with the longitudinal direction.
[0013]
The coupling loop 251A is a plurality of closed loops having a first polarity, and is configured by connecting the first portion 252 and the second portion 253 with a pair of connection conductors 254. Similarly, the coupling loop 251B is a plurality of closed loops of the second polarity, and is configured by connecting the first portion 252 'and the second portion 253' with a pair of connection conductors 254 '. The first portions 252, 252 'are arranged in a first magnetic flux region in which the magnetic field generator 111A is arranged, and the second portions 253, 253' are arranged in the first magnetic flux region in which the magnetic flux sensors 124, 126, 128 are arranged. It is arranged in the two magnetic flux regions. Coupling loops 251A and 251B are electrically isolated from each other.
[0014]
The plurality of first coupling loops 251 </ b> A are arranged such that the first portion 252 draws an arc along the measurement axis 114 outside the circumference of the scale 200. The second portion 253 is arranged on the rotation center side of the scale 200 so as to draw an arc along the measurement axis 114.
Similarly, the plurality of second coupling loops 251B are arranged such that the first portion 252 'draws an arc along the measurement axis 114 on the rotation center side of the scale 200. The second portion 253 'is interleaved and arranged along the measurement axis 114 with the second portion 253 of the first coupling loop 251A.
[0015]
The terminals 112A and 112B of the magnetic field generator 111 are connected to an excitation signal generator 150 for transmission. The excitation signal generator 150 supplies a time-varying excitation signal to the terminal 112A of the magnetic field generator 111 according to a control signal from the control unit 160. As a result, a time-varying current flows from the terminal 112A to the terminal 112B through the magnetic field generator 111. In response, the first magnetic field generator portion 111A rises from the page of FIG. 2 inside the magnetic field generator portion 111A and descends to the page of FIG. 1 outside the loop created by the magnetic field generator portion 111A. Generates a magnetic field.
[0016]
On the other hand, the second magnetic field generator portion 111B rises from the plane of FIG. 2 outside the loop formed by the magnetic field generator section 111B, and rises from the plane of FIG. 2 inside the loop formed by the magnetic field generator section 111B. A primary magnetic field is generated that descends to As a result, current is induced in the coupling loops 251A and 251B so as to cancel the magnetic field change. That is, the induced current flowing in the first portions 252, 252 'of the coupling loop is in the opposite direction to the current flowing in the corresponding adjacent portions of the magnetic field generator portions 111A, 111B, respectively. Adjacent second portions 253 and 253 'carry loop currents of opposite polarity. As a result, a secondary magnetic field is generated such that a magnetic field portion of the opposite polarity is periodically distributed in the measurement axis 114 direction. The wavelength λ of the periodic secondary magnetic field is equal to the spacing between successive second portions 253 (or 253 ′).
[0017]
The magnetic flux sensors 124, 126, 128 are formed by conductor segments 129 and 129 'respectively forming a part of a plurality of sinusoidal waveforms formed on both sides of the insulating layer of the printed circuit board constituting the read head 100. The segments 129 and 129 'are connected via a through wire 130 to form a positive loop 132 and a negative loop 134 alternately in each of the magnetic flux sensors 124, 126 and 128. That is, the space between the pair of the adjacent positive and negative polarity loops 132 and 134 has a wavelength λ in the direction of the measurement axis 114 and a phase shift of λ / 3 between the magnetic flux sensors 124, 126 and 128. This means that the inductive regions having a periodic pattern whose width is modulated are arranged.
[0018]
Unnecessary electrical coupling from the magnetic field generator 111 to the magnetic flux sensors 124, 126, 128 (change in induced current independent of position and scale) can be avoided by the above configuration. That is, the primary magnetic fields generated by the first and second magnetic field generator portions 111A and 111B are directed in opposite directions near the magnetic flux sensors 124, 126, 128. Therefore, the primary magnetic fields cancel each other in the occupied area of the magnetic flux sensors 124, 126, 128. Ideally, the primary magnetic field should be completely canceled in this region.
[0019]
In the measurement operation, an excitation signal that changes with time is supplied from the excitation signal generator 150 to the magnetic field generator terminal 112A. Thereby, the first magnetic field generator portion 111A generates a first fluctuating magnetic field in a first direction, and the second magnetic field generator portion 111B generates a second fluctuating magnetic field in a second direction opposite to the first direction. Generates a fluctuating magnetic field.
[0020]
The plurality of first coupling loops 251A are inductively coupled to the first magnetic field generator portion 111A by a first magnetic field generated by the first magnetic field generator portion 111A. As a result, the induced current flows clockwise in each of the first coupling loops 251A.
At the same time, the plurality of second coupling loops 251B are inductively coupled to the second magnetic field generator portion 111B by the second magnetic field generated by the second magnetic field generator portion 111B. This induces a counterclockwise current in each of the second coupling loops 251B.
That is, current flows in opposite directions through the second portions 253 and 253 'of the coupling loops 251A and 251B.
[0021]
The clockwise current flowing through the second portion 253 of the first coupling loop 251A generates a third magnetic field in the second portion 253 in a direction descending to the plane of FIG. The counterclockwise current flowing through the second portion 253 'of the second coupling loop 251B generates a fourth magnetic field in the second portion 253' in a direction rising from the plane of FIG. This creates a net fluctuating magnetic field along the measurement axis 114. This fluctuating magnetic field has a wavelength equal to the wavelength λ of the magnetic flux sensors 124, 126, 128.
[0022]
The output signal obtained by the first magnetic flux sensor 124 as a function of the movement angle θ and sent to the reception signal processing circuit 140 is obtained by the second magnetic flux sensor 126 as a function of the movement angle θ and transmitted to the reception signal processing circuit 140. The output signal to be sent is 120 ° out of phase.
Similarly, the output signal obtained by the third magnetic flux sensor 128 as a function of the movement angle θ and sent to the reception signal processing circuit 140 is obtained by the second magnetic flux sensor 126 as a function of the movement angle θ, The output signal sent to 140 is out of phase by 120 °.
[0023]
The reception signal processing circuit 140 samples output signals from the magnetic flux sensors 124, 126, and 128 at a predetermined sampling period Ts, converts the signals into digital values, and sends the digital values to the control unit 160. The sampling period Ts is determined based on a relationship between the maximum value (hereinafter, referred to as a response speed) permitted as a relative movement speed between the read head 100 and the scale 200 and the wavelength λ. For example, when the response speed is 20 rps and the length of one circumference of the measurement axis 114 is 3 × λ, the sampling period Ts needs to be smaller than 1 / (20 × 3 × 2) = 8.34 ms. is there. Here, a description will be given assuming that Ts is set to 8.33 ms.
[0024]
The control unit 160 processes the digitized output signals from the magnetic flux sensors 124, 126, and 128 at the sampling period Ts, and counts the wave number Nw of the output signals. Further, the phase angle within the range of one wavelength λ of the output signal is calculated, and the movement angle θ within the range of one wavelength λ is calculated based on this. Further, the control unit 160 determines the direction of the relative movement between the read head 100 and the scale 200 based on the phase difference between the outputs of the magnetic flux sensors 124, 126, 128. The control unit 160 outputs a relative movement angle θt from a certain origin between the read head 100 and the scale 200 using the wave number Nw and the movement angle θ. Further, the control unit 160 sends a control signal to the transmission excitation signal generator 150 to generate a time-varying excitation signal.
[0025]
The display unit 300 is for displaying the movement angle θt of the read head 100 calculated by the control unit 160.
[0026]
Next, specific configurations of the reception signal processing circuit 140 and the control unit 160 will be described with reference to FIG. The reception signal processing circuit 140 includes three sample / hold circuits 141, 142, 143 and three A / D conversion circuits 144, 145, 146.
The sample hold circuits 141, 142, and 143 temporarily hold output signals of the magnetic flux sensors 124, 126, and 128 each time a control signal transmitted from the arithmetic and control circuit 167 is received at each sampling period Ts. It is configured. The A / D conversion circuits 144, 145, and 146 convert the outputs of the sample and hold circuits 141, 142, and 143 into digital values, respectively.
[0027]
The control unit 160 includes comparison circuits 161, 162, and 163, a storage unit 164, a wave number counting unit 165, a movement amount within one wavelength calculation unit 166, a calculation control circuit 167, and a display control unit 168. .
The comparison circuits 161, 162, and 163 compare the output values from the A / D conversion circuits 144, 145, and 146 with predetermined threshold values, respectively, and convert the output values into 1-bit digital values. Thereby, the output signals VR, VS, VT from the magnetic flux sensors 124, 125, 126 are converted into 1-bit pulse period signals VR ', VS', VT ', respectively, as shown in FIG. The wave number counting unit 165 counts the wave number Nw of the output signal based on the state of the one-bit signal.
[0028]
The storage unit 164 includes a switch SW. The switch SW is provided for further sampling the sampling signals of the sample and hold circuits 141, 142, and 143 at a period Ts' longer than the sampling period Ts and storing the signals in the storage unit 164. Here, considering that even if the display update cycle of the display unit 300 is about 125 ms, the usability of the user does not decrease so much, Ts' is set to the same as the display update cycle, 15 times Ts (125 ms). . Since the sampling operation of the storage unit 164 only needs to be performed once in the display update period, the following description will be made assuming that the display update period and the sampling period in the storage unit 164 are the same. However, they need not necessarily be the same, and the following description does not limit the scope of the present invention.
[0029]
Based on the sampling values of the output signals VR, VS, and VT stored in the storage unit 164, the one-wavelength movement amount calculation unit 166 calculates any two of the output signals VR, VS, and VT, for example, VS and VT. Is subtracted to generate a signal VQ. This signal VQ is a two-phase signal having a phase difference of 90 degrees from the remaining signal VR. From these two-phase signals VR and VQ, a relative movement angle θ within a range of one wavelength λ is obtained by an operation shown below (hereinafter referred to as a tan -1 operation) and output to the operation control circuit 167. .
[0030]
(Equation 1)
θ = A (λ / 2π) tan -1 [−VQ / VR · √3]
(A is a constant)
[0031]
The counting process in the wave number counting unit 165 is a simple process that only determines the period of 1, 0 of the three sampling signals converted into digital values, while the moving angle θ in the one-wavelength moving amount calculating unit 166. Is a procedure for converting the three-phase signals VR, VS, and VT into two-phase signals VQ, VR, and the above-described tan -1 calculation. When this is converted into the required time, the former calculation is completed in about 1 ms even when a 4-bit CPU is used, whereas the latter calculation requires about 25 ms in a similar environment. Assuming that it takes about 2.5 ms to acquire the output periodic signals VR, VS, and VT, the time from acquiring the signals VR, VS, and VT to calculating the movement angle θt is 28.5 ms (see FIG. 5A )). Therefore, if the sampling period Ts is on the order of 8.33 ms, the calculation cannot be completed within the sampling period (response speed excess (overspeed)).
[0032]
Therefore, in the present embodiment, as shown in FIG. 5B, the sampling process of the sample and hold circuits 141 to 143 ((1)) and the counting process of the wave number Nw of the wave number counting unit 165 ((2)) are performed. Performed every cycle Ts = 8.33 ms. When viewed within the display update period Ts' = 125 ms, the wave number Nw is counted 15 times.
On the other hand, a process of calculating the moving angle θ within the range of one wavelength λ by the intra-wavelength moving amount calculating unit 166, calculating the moving angle θt based on the θ and the wave number Nw, and displaying the calculated moving angle θt on the display unit 300 (hereinafter, referred to as processing) , Measurement data calculation display processing) is based on data obtained by the sampling processing of the sample and hold circuits 141 to 143 (BS in FIG. 5B) at the beginning of the display update cycle Ts ′, and based on the display update cycle Ts ′ = Execute the program divided into multiple times within 125 ms. In the case of the above example, as shown in FIG. 5, this angle measurement data calculation display processing is divided into 15 steps (steps 1), 2), 3),... 15)) (the time required for each step). (25/15 = 1.67 ms) is preferably executed immediately after the counting process ((2)) of each wave number Nw.
As shown in FIG. 5B, the division and execution are performed by counting the wave number Nw ((2)) and sampling the sample and hold circuits 141-143 ((1)) for the sampling period Ts. This is because it is necessary to perform the angle measurement data calculation display processing in this interval.
[0033]
According to such data processing, acquisition processing for sampling the output periodic signals VR, VS, and VT by the sample and hold circuits 141, 142, and 143 ((1), required time of about 2.5 ms), and counting processing of the wave number Nw ((2) ▼), the sum of the time of each division step of the measurement data calculation display processing is 2.5 + 1 + 1.67 = 5.17 ms. Even if the sampling period Ts is 8.34 ms, there is a sufficient margin, and the reception signal processing circuit has a sufficient margin. The intermittent operation (HALT) of the control unit 140 and the control unit 160 can be executed (in the above example, the HALT time is 3.16 ms). Actually, the processing (1) and the processing 1), 2), 3),... Or 15) can be performed in parallel by the reception signal processing circuit 140 and the control unit 160, respectively. Can be longer.
[0034]
Each time the calculation control circuit 167 calculates the movement angle θt, which is a new calculation value, for each cycle Ts ′ (= 15 × Ts = 125 ms), the display control unit 168 calculates the movement angle, which is a new calculation value, θt is displayed on the display unit 300.
[0035]
As described above, the embodiment has been described by giving numerical values, but the above example is only an example. For example, in the measurement data calculation display processing, the method of determining the number of divisions in the division step is not limited to the above example. In the above example, the display update period Ts' is set to 125 ms, but this can be changed to a longer or shorter length as required. For example, if it is desired to set the display update period Ts' to about 85 ms, the sampling processing of the sampling period Ts = 8.33 ms can be performed ten times during this 85 ms. And it is sufficient.
Further, in the above example, the division processing of the measurement data calculation display processing is performed every time one count processing is performed by the wave number counting unit 165. However, the division processing is not necessarily performed every time, and may be performed once. It does not matter (for example, division processing is performed once every two counts of the wave number Nw). Further, in the above-described embodiment, an electromagnetic induction type rotary encoder has been described as an example, but it is needless to say that the present invention can be applied to an electromagnetic induction type linear encoder.
[0036]
【The invention's effect】
As described above, according to the counting device of the incremental encoder according to the present invention, it is possible to perform the intermittent operation as appropriate while securing a sufficient moving speed of the movable unit, thereby suppressing an increase in power consumption. It has the effect of being able to.
[Brief description of the drawings]
FIG. 1 shows an outline of the entire structure of an incremental type electromagnetic induction rotary encoder according to an embodiment of the present invention.
FIG. 2 schematically shows a detailed structure of an incremental electromagnetic induction type rotary encoder according to an embodiment of the present invention.
FIG. 3 shows a specific configuration of a reception signal processing circuit 140 and a control unit 160 shown in FIG.
FIG. 4 is a diagram illustrating periodic signal periodic signals VR, VS, and VT output from the magnetic flux sensors 124, 126, and 128, and pulse periodic signals VR ′, VS ′, and VT ′ obtained by converting these into 1-bit digital signals. FIG.
FIG. 5 is a conceptual diagram showing a procedure of data processing according to the present embodiment.
[Explanation of symbols]
100 read head, 200 scale, 111 magnetic field generator, 111A first magnetic field generator part, 111B second magnetic field generator part, 112A, 112B terminal, 124, 126, 128 magnetic flux sensor 129, 129 '... segment, 114 ... measurement axis, 140 ... reception signal processing device, 141, 142, 143 ... sample hold circuit, 144, 145, 146 ... A / D conversion circuit, 150 ... transmission excitation signal generator, 160: control unit, 161, 162, 163: comparison circuit, 164: storage unit, 165: wave number counting unit, 166: movement amount calculation unit within one wavelength, 167: calculation control circuit, 168: display control unit, 251A, 251B ... the coupling loop, 252, 252 '... the first part, 253, 253' ... the second part, 254, 2 4 '... a pair of connecting conductors, 300 ... display unit

Claims (4)

  1. An incremental encoder counting device that calculates and outputs a relative movement amount of the two members in a display update cycle based on a periodic signal output in accordance with the relative movement of the two members arranged opposite to each other,
    First sampling means for sampling the periodic signal at a first sampling period shorter than the display update period;
    Wave number counting means for counting the wave number of the periodic signal based on the result of the sampling,
    Second sampling means for sampling the periodic signal at a second sampling cycle corresponding to the display update cycle;
    An operation of calculating a relative movement amount of the two members within one cycle of the periodic signal based on a sampling result of the second sampling means in a time-division manner for each of the first sampling cycles within the second sampling cycle Means for counting an incremental encoder.
  2. The counting device for an incremental encoder according to claim 1, wherein each processing of the calculation performed in the time-division manner is performed in a time interval during which the counting operation by the wave number counting means is not performed in the first sampling period. .
  3. 3. The counting device according to claim 1, wherein the sampling by the second sampling unit is performed at least once in the display update cycle.
  4. A period in which a fluctuating magnetic field generated by a magnetic field generator provided on one of the two members arranged oppositely causes an induced current to be generated on a receiving electrode provided on the other member, and is output in accordance with the relative movement of the two members. In the counting device of the electromagnetic induction type incremental encoder that calculates and outputs the relative movement amount of the two members in the display update cycle based on the signal,
    First sampling means for sampling the periodic signal at a first sampling period shorter than the display update period;
    Wave number counting means for counting the wave number of the periodic signal based on the result of the sampling,
    Second sampling means for sampling the periodic signal at a second sampling cycle corresponding to the display update cycle;
    An operation of calculating a relative movement amount of the two members within one cycle of the periodic signal based on a sampling result of the second sampling means in a time-division manner for each of the first sampling cycles within the second sampling cycle And a means for counting an electromagnetic induction type incremental encoder.
JP2002377900A 2002-12-26 2002-12-26 Incremental encoder counting device Active JP4074188B2 (en)

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Cited By (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE102008046741A1 (en) 2008-09-11 2010-03-18 Dr. Johannes Heidenhain Gmbh Inductive position sensor, measuring system equipped therewith and method for operating a position sensor
JP2012163412A (en) * 2011-02-04 2012-08-30 Nsk Ltd Physical quantity measurement instrument for rotating member
JP2016527520A (en) * 2013-08-12 2016-09-08 ジーディーイー テクノロジー リミテッドGde Technology Ltd Position sensor

Cited By (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE102008046741A1 (en) 2008-09-11 2010-03-18 Dr. Johannes Heidenhain Gmbh Inductive position sensor, measuring system equipped therewith and method for operating a position sensor
JP2012502286A (en) * 2008-09-11 2012-01-26 ドクトル・ヨハネス・ハイデンハイン・ゲゼルシヤフト・ミツト・ベシユレンクテル・ハフツングDr. Johannes Heidenhain Gesellschaft Mit Beschrankter Haftung Inductive position sensor, measuring system with inductive position sensor, and operation method of position sensor
US8451000B2 (en) 2008-09-11 2013-05-28 Dr. Johannes Heidenhain Gmbh Inductive position sensor, measuring system equipped therewith and method for operating a position sensor
JP2012163412A (en) * 2011-02-04 2012-08-30 Nsk Ltd Physical quantity measurement instrument for rotating member
JP2016527520A (en) * 2013-08-12 2016-09-08 ジーディーイー テクノロジー リミテッドGde Technology Ltd Position sensor
US10564013B2 (en) 2013-08-12 2020-02-18 Gde Technology Ltd Position sensor

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