Redundant encoder

Abstract

[Problem] To provide an encoder capable of detecting a rotation angle within one rotation and detecting the amount of multi-rotations, both with redundancy.　[Solution] A redundant encoder 100 has a configuration comprising: a first rotation detection unit 10 that includes a magnetic field generation unit 5 having two or more N poles 2 and two or more S poles 3 and detects a rotation amount with a resolution of less than or equal to 1 / 2 rotation; and a second rotation detection unit 20 that detects a rotation amount with a resolution higher than that of the first rotation detection unit 10. A permanent magnet is used for the magnetic field generation unit 5. The first rotation detection unit 10 has a configuration including a magnetic power generation element 26 that exhibits a large Barkhausen effect and a magnetic detection element 27 that exhibits a Hall effect or a magnetoresistance effect.

Description

Redundant Encoders

[0001] The present invention relates to a redundant encoder, and more particularly to a technique for improving reliability in detecting a rotation angle within one rotation and the amount of multiple rotations.

[0002] FIG. 7 is an explanatory diagram showing the configuration and key points of operation of a conventional encoder having a single rotation angle detector, as disclosed in Patent Document 1 (see below). As shown in the figure, this encoder 700 is composed of a single rotation detector 720, which detects the rotation angle within one rotation and calculates the amount of multiple rotations from the integrated value. The output signal from the rotation detector 720 is sent to a signal processing circuit 728, which obtains the rotation angle within one rotation. The resolution is, for example, 1 / 4096 rotation or less. The rotation detector 720 and signal processing circuit 728 receive power from an external power source 729.

[0003] FIG. 8 is an explanatory diagram showing the configuration and key points of operation of a conventional encoder having two rotation detectors, as disclosed in Patent Document 2 (see below). As shown in the figure, this encoder 800 is configured with two rotation detectors: a second rotation detector 820 that detects the rotation angle within one rotation, and a first rotation detector 810 that detects the amount of multiple rotations. Therefore, the second rotation detector 820 detects the rotation angle within one rotation, while the first rotation detector 810 detects the amount of multiple rotations. The output signal from the second rotation detector 820 is sent to a second signal processing circuit 828, which obtains the rotation angle within one rotation. The resolution is, for example, 1 / 4096 rotation or less. The second rotation detector 820 receives power from an external power source 829.

[0004] The first rotation detection unit 810 is composed of a magnetic power generation element 86, a magnetic detection element 87 having the Hall effect or magnetoresistance effect, and a magnetic field generation unit 85 having a north pole and a south pole. The magnetic field generation unit 85 is provided coaxially with the second rotation detection unit 820, and the magnetic field generated by the magnetic power generation element 86 generates electricity, while changes in the magnetic field due to rotation are detected by the magnetic detection element 87. The output signal from the magnetic detection element 87 is sent to a first signal processing circuit 818, which detects the amount of multiple rotations. The resolution is 1 / 1 rotation or less. The first rotation detection unit 810 does not have an external power supply. The output voltage from the magnetic power generation element 86 is supplied to the first signal processing circuit 818.

[0005] In this encoder 800, when power is supplied from the external power supply 829, the rotation angle within one rotation is detected at the resolution of the second rotation detection unit 820. For example, this is 1 / 4096 rotation or less. On the other hand, the amount of multiple rotations is not only detected by the first rotation detection unit 810, but is also obtained from the integrated amount of the rotation angle within one rotation detected by the second rotation detection unit 820. In other words, the amount of multiple rotations is detected redundantly.

[0006] Japanese Utility Model Application Publication No. 02-97619 "Multi-rotation absolute value encoder" Japanese Patent Application Publication No. 2014-137233 "Motor"

[0007] Encoder 700, which has a single rotation detector, cannot detect the rotation angle within one rotation or the amount of multiple rotations with redundancy. Encoder 800, which has two rotation detectors, can detect the amount of multiple rotations with redundancy, but cannot detect the rotation angle within one rotation with redundancy. Therefore, both of the conventional technologies have limitations in terms of improving detection reliability.

[0008] Therefore, the problem that the present invention aims to solve is to provide an encoder that eliminates the problems of the prior art and is capable of detecting both the rotation angle within one rotation and the amount of multiple rotations with redundancy.

[0009] The inventors of the present application have investigated the above-mentioned problem. Based on the fact that the first rotation detection unit in the conventional encoder consisting of the two rotation detection units is composed of only one north pole and one south pole, which is the reason for the lack of redundancy, they have found that this problem can be solved by using a magnetic field generating unit with two or more north poles and two or more south poles, and have completed the present invention based on this. That is, the invention claimed in this application, or at least the invention disclosed therein, as a means for solving the above-mentioned problem is as follows.

[0010] [1] A redundant encoder comprising: a first rotation detection unit having a magnetic field generating unit with two or more north and south poles and detecting the amount of rotation with a resolution of 1 / 2 rotation or less; and a second rotation detection unit detecting the rotation angle with a resolution higher than that of the first rotation detection unit, thereby providing redundancy for both the rotation angle within one rotation and the amount of multiple rotations. [2] The redundant encoder according to [1], characterized in that the first rotation detection unit comprises a magnetic generating element having the large Barkhausen effect and a magnetic detection element having the Hall effect or the magnetoresistive effect. [3] The redundant encoder according to [2], characterized in that it comprises a first signal processing circuit that processes an output signal from the first rotation detection unit and a second signal processing circuit that processes an output signal from the second rotation detection unit. [4] The redundant encoder according to [3], characterized in that the second rotation detection unit and the second signal processing circuit are provided with external power sources.

[0011] [5] The redundant encoder according to any one of [1], [2], [3], and [4], characterized in that the second rotation detection unit is an optical, magnetic, electromagnetic induction, capacitance, or other type of rotation detector. [6] The redundant encoder according to any one of [1], [2], [3], and [4], characterized in that the resolution of the second rotation detection unit is 1 / 4096 rotation or less. [7] The redundant encoder according to any one of claims 1, 2, 3, and 4, characterized in that a rotation angle T1s within one rotation with a resolution of 1 / 2 rotation or less is detected from the rotation amount T1 obtained by the first rotation detection unit, and a multi-rotation amount T1m is detected by integrating the rotation amount T1, and a rotation angle T2s within one rotation with a resolution higher than that obtained by the first rotation detection unit is detected from the rotation angle T2 obtained by the second rotation detection unit, and the multi-rotation amount T2m is detected by integrating the rotation angle T2. [8] A redundant encoder according to [7], characterized in that by comparing the rotation angle T1s and the rotation angle T2s, the rotation angle within one rotation is detected with redundancy that matches to a resolution of 1 / 2 rotation or less, and by comparing the multi-rotation amount T1m and the multi-rotation amount T2m, the multi-rotation amount is detected with redundancy that matches to a resolution of one rotation.

[0012] [9] The redundant encoder according to [7], wherein the second rotation detection unit and the second signal processing circuit are equipped with external power supplies, the resolution of the second rotation detection unit is 1 / 4096 rotation or less, and by comparing the rotation angle T1s and the rotation angle T2s, the rotation angle within one rotation is detected to 1 / 4096 rotation or less, which is the resolution of the rotation angle T2, and is detected with redundancy to 1 / 2 rotation or less, which is the resolution of the rotation amount T1, and by comparing the multi-rotation amount T1m and the multi-rotation amount T2m, the multi-rotation amount is detected with redundancy to match up to the resolution of one rotation.

[10] The redundant encoder according to either [8] or [9], wherein a comparison means is provided for comparing the rotation angle T1s and the rotation angle T2s.

[11] The redundant encoder according to either [8] or [9], wherein a comparison means is provided for comparing the multi-rotation amount T1m and the multi-rotation amount T2m.

[0013] Because the redundant encoder of the present invention is configured as described above, it can detect both the rotation angle within one rotation and the amount of multiple rotations with redundancy, thereby improving detection reliability. Furthermore, the amount of multiple rotations can be detected regardless of whether an external power source is present or operating. In other words, even if a malfunction occurs in the external power source, the first rotation detection unit, which has a resolution of 1 / 2 rotation or less, can still detect the amount of multiple rotations up to a resolution of one rotation.

[0014] FIG. 1 is an explanatory diagram showing the basic configuration of a redundant encoder of the present invention; FIG. 2 is an explanatory diagram showing the configuration and operation of a redundant encoder of the present invention in which a first rotation detection unit is equipped with a magnetic power generation element or the like; FIG. 3 is an explanatory diagram showing the configuration and operation of a redundant encoder of the present invention equipped with a signal processing circuit; FIG. 4 is an explanatory diagram showing the rotation detection operation in the redundant encoder of the present invention; FIG. 5 is a second explanatory diagram showing the rotation detection operation in the redundant encoder of the present invention; FIG. 6 is an explanatory diagram showing the configuration of an embodiment of a redundant encoder of the present invention; FIG. 7 is an explanatory diagram showing the configuration and operation of a conventional encoder having one rotation angle detection unit; and FIG. 8 is an explanatory diagram showing the configuration and operation of a conventional encoder having two rotation angle detection units.

[0015] The present invention will be described in detail below with reference to the drawings. Figure 1 is an explanatory diagram showing the basic configuration of a redundant encoder of the present invention. As shown in the figure, this redundant encoder 100 mainly comprises a magnetic field generating unit 5 having two or more north poles 2 and two or more south poles 3, a first rotation detecting unit 10 that detects the amount of rotation of an object to be detected with a resolution of 1 / 2 rotation or less, and a second rotation detecting unit 20 that detects the amount of rotation of the same object to be detected with a higher resolution than the first rotation detecting unit 10. A permanent magnet can be used for the magnetic field generating unit 5.

[0016] In this redundant encoder 100, the magnetic field generating unit 5 of the first rotation detection unit 10 has two or more north poles 2 and two or more south poles 3, and therefore detects the amount of rotation with a resolution of 1 / 2 rotation or less. In other words, this allows the amount of multiple rotations to be detected, and the rotation angle within one rotation to be detected with a resolution of 1 / 2 rotation or less. On the other hand, the second rotation detection unit 20 has a higher resolution than the first rotation detection unit 10, and therefore can detect the rotation angle within one rotation with higher accuracy than the first rotation detection unit 10, and can also detect the amount of multiple rotations by integrating the detection results (rotation angle). Therefore, this redundant encoder 100 can perform redundant detection of both the rotation angle within one rotation and the amount of multiple rotations.

[0017] The total number of north poles 2 and south poles 3 in the magnetic field generating unit 5 of the redundant encoder 100 of the present invention is four or more, and the resolution improves as the number of poles increases, such as six or eight. However, the desired effect of the present invention can be sufficiently obtained with two north poles 2 and two south poles 3, a total of four poles.

[0018] 2 is an explanatory diagram showing the configuration and operation of a redundant encoder of the present invention in which the first rotation detection unit is equipped with a magnetic generating element, etc. As shown in the figure, the redundant encoder 2100 can be configured such that the first rotation detection unit 210 includes a magnetic field generating unit 25 having two or more north poles 22 and two or more south poles 23, a magnetic generating element 26 having the large Barkhausen effect, and a magnetic detection element 27 having the Hall effect or magnetoresistive effect.

[0019] The magnetic field generating unit 25 is arranged coaxially with the second rotation detecting unit 220, and the magnetic field generated by the magnetic field generating unit 25 causes the magnetic generating element 26 to generate electricity, and the change in the magnetic field due to rotation is detected by the magnetic detecting element 27.

[0020] 3 is an explanatory diagram showing the configuration and operation of a redundant encoder 3100 of the present invention equipped with a signal processing circuit. As shown in the figure, this redundant encoder 3100 can be configured to include, in addition to the configuration shown in FIGS. 1 and 2, a first signal processing circuit 318 that processes the output signal from the first rotation detection unit 310, and a second signal processing circuit 328 that processes the output signal from the second rotation detection unit 320.

[0021] According to the redundant encoder 3100 configured as described above, output signals from the magnetic generating element 36 and magnetic detecting element 37 of the first rotation detecting unit 310 are sent to the first signal processing circuit 318, where they are processed to detect the amount of multiple rotations T1. Furthermore, because the magnetic field generating unit 35 has two or more north poles 32 and two or more south poles 33, the resolution is ½ rotation or less. Therefore, the rotation angle within one rotation can also be detected with a resolution of ½ rotation or less. The first rotation detecting unit 310 does not have an external power supply. The output voltage from the magnetic generating element 36 is supplied to the first signal processing circuit 318.

[0022] On the other hand, the output signal from the second rotation detection unit 320 is sent to a second signal processing circuit 328, where it is processed to detect a rotation angle T2 within one rotation. The resolution of the second rotation detection unit 320 can be, for example, 1 / 4096 rotation or less, but is not limited to this.

[0023] As shown in the figure, the second rotation detection unit 320 and second signal processing circuit 328 of this redundant encoder 3100 are configured to be equipped with an external power supply 329. In this encoder 3100, while power is being supplied from the external power supply 329, the rotation angle T2 within one rotation is detected at the resolution of the second rotation detection unit 320, for example, at the resolution of 1 / 4096 rotation or less as described above. In addition, the rotation angle within one rotation is also detected by the first rotation detection unit 310 at a resolution of 1 / 2 rotation or less, so the rotation angle within one rotation is detected redundantly.

[0024] Furthermore, the amount of multiple rotations T2 is detected by the first rotation detection unit 310 and is also obtained from the integrated amount of rotation angles within one rotation detected by the second rotation detection unit 320, so that the amount of multiple rotations is also detected redundantly. In this way, based on the comparison and synthesis CP of the amount of multiple rotations T1 and the rotation angle T2 within one rotation obtained by this redundant encoder 3100, these rotation detections are performed with redundancy.

[0025] In the redundant encoder 3100 of the present invention, which aims to be able to detect both the rotation angle within one rotation and the amount of multiple rotations with redundancy, the external power supply 329 is necessary to operate the second rotation detection unit 320. However, even if an abnormality occurs in the external power supply 329 and the second rotation detection unit 320 stops operating, the amount of multiple rotations can be detected up to a resolution of one rotation by the action of the first rotation detection unit 310, which has a resolution of 1 / 2 rotation or less.

[0026] The second rotation detector 320 may be an optical, magnetic, electromagnetic induction, capacitance, or other type of rotation detector, such as a magnetic resolver, an optical encoder, or a capacitance encoder.

[0027] 4 is an explanatory diagram showing the rotation detection function of the redundant encoder of the present invention. As shown in the figure, the redundant encoder 100 of the present invention performs the following rotation detection functions: detection of a rotation angle T1s within one rotation, which has a resolution of 1 / 2 rotation or less, from the rotation amount T1 obtained by the first rotation detector 10; detection of a multiple rotation amount T1m by integrating the rotation amount T1; detection of a rotation angle T2s within one rotation, which has a higher resolution than that obtained by the first rotation detector, for example, a resolution of 1 / 4096 rotation or less, from the rotation angle T2 obtained by the second rotation detector 20; and detection of a multiple rotation amount T2m by integrating the rotation angle T2.

[0028] The multi-rotation amount T1m derived from the first rotation detection unit 10 and the rotation angle within one rotation T2s derived from the second rotation detection unit 20 are combined to obtain a rotation amount U with increased reliability as the rotation angle within one rotation and the multi-rotation amount.

[0029] As shown in the figure, the rotation angle within one rotation is detected with redundancy, matching to a resolution of 1 / 2 rotation or less, by comparing rotation angle T1s and rotation angle T2s (CPs). On the other hand, the amount of multiple rotations is detected with redundancy, matching to a resolution of one rotation, by comparing multiple rotation amounts T1m and T2m (CPm).

[0030] FIG. 5 is a second explanatory diagram illustrating the rotation detection function of the redundant encoder of the present invention. The lower part of the figure shows a diagram illustrating the angular positions within one rotation, stretched into strips, for the first rotation detector 510 (obtaining the rotation amount T1) and the second rotation detector 520 (obtaining the rotation angle T2) constituting the redundant encoder 5100 shown in the upper part of the figure, and showing the angular positions that can be compared. Note that the magnetic field generator 55 constituting the first rotation detector 510 has two or more north poles 52 and two or more south poles 53, but here an example is shown in which there are two poles each, for a total of four poles. In other words, the detection resolution of the rotation angle within one rotation in the first rotation detector 510 is 1 / 2 rotation. On the other hand, the detection resolution of the rotation angle within one rotation in the second rotation detector 520 is 1 / 4096 rotation.

[0031] In one rotation, that is, in the range of 0° to 360°, 0° is detected as 0 / 2 rotation by the first rotation detection unit 510 and 0 / 4096 rotation by the second rotation detection unit 520, that is, as 0 rotation by both rotation detection units. Similarly, 360° is detected as 2 / 2 rotation by the first rotation detection unit 510 and 4096 / 4096 rotation by the second rotation detection unit 520, that is, as one rotation by both rotation detection units.

[0032] In addition, in the redundant encoder 5100 of the present invention, 180° is detected as 1 / 2 rotation by the first rotation detector 510 and as 2048 / 4096 rotation by the second rotation detector 520. In other words, it is detected as 1 / 2 rotation or less by both rotation detectors. In other words, redundant detection is performed up to 1 / 2 rotation, which is the resolution of the first rotation detector 510 (T1).

[0033] The redundant encoder of the present invention can be configured to include a comparison means for comparing rotation angle T1s with rotation angle T2s. By comparing rotation angle T1s with rotation angle T2s by the comparison means, the rotation angle within one rotation can be detected with the resolution of rotation angle T2 (for example, 1 / 4096 rotation or less), and can also be detected with redundancy up to 1 / 2 rotation, which is the resolution of rotation amount T1.

[0034] The redundant encoder of the present invention can also be configured to include a comparison means for comparing the multi-rotation amount T1m with the multi-rotation amount T2m. By comparing the multi-rotation amount T1m with the multi-rotation amount T2m by the comparison means, the multi-rotation amount can be detected with redundancy that matches up to the resolution of one rotation.

[0035] 6 is an explanatory diagram showing the configuration of an embodiment of a redundant encoder of the present invention. As shown in the figure, the magnetic field generating unit 65 of the first rotation detection unit 610 of this redundant encoder 6100 is composed of two north poles 62 and two south poles 63, for a total of four poles. In addition, a resolver is used as the second rotation detection unit 620.

[0036] The redundant encoder of the present invention can detect both the rotation angle within one rotation and the amount of multiple rotations with redundancy, thereby improving the reliability of detection. Therefore, this invention has high industrial applicability in the fields of encoder manufacturing and use, and all related fields.

[0037] 2, 22, 32, 62...North pole 3, 23, 33, 63...South pole 5, 25, 35, 65...Magnetic field generating unit 10, 210, 310, 510, 610...First rotation detecting unit 20, 220, 320, 520, 620...Second rotation detecting unit 26, 36, 66...Magnetic power generating element 27, 37, 67...Magnetic detecting element 100, 2100, 3100, 5100, 6100...Redundant encoder 318, 618...First signal processing circuit 328, 628...Second signal processing circuit 329...External power supply CP...Comparison and synthesis CPm...Comparison of multi-rotation amount T1m and multi-rotation amount T2m CPs...Comparison of rotation angle T1s and rotation angle T2s T1...Amount of rotation obtained by first rotation detecting unit (amount of multi-rotation) T1m...Amount of multi-rotation T1s...rotation angle within one rotation T2...rotation angle obtained by second rotation detection unit T2m...amount of multiple rotations T2s...rotation angle within one rotation U...amount of rotation with improved reliability 700...encoder (prior art) 720...rotation detection unit 728...signal processing circuit 729...external power supply 800...encoder (prior art) 810...first rotation detection unit 85...magnetic field generation unit 86...magnetic power generation element 87...magnetic detection element 818...first signal processing circuit 820...second rotation detection unit 828...second signal processing circuit 829...external power supply

Claims

1. A redundant encoder comprising: a first rotation detection unit that has a magnetic field generating unit with two or more north and south poles and detects the amount of rotation with a resolution of 1 / 2 rotation or less; and a second rotation detection unit that detects the rotation angle with a higher resolution than the first rotation detection unit, thereby providing redundancy in both the rotation angle within one rotation and the amount of multiple rotations.

2. The redundant encoder according to claim 1, wherein the first rotation detection unit comprises a magnetic generating element having the large Barkhausen effect and a magnetic detecting element having the Hall effect or the magnetoresistive effect.

3. A redundant encoder according to claim 2, characterized in that it comprises a first signal processing circuit for processing an output signal from the first rotation detection unit, and a second signal processing circuit for processing an output signal from the second rotation detection unit.

4. The redundant encoder according to claim 3, wherein the second rotation detection unit and the second signal processing circuit are provided with an external power supply.

5. A redundant encoder according to any one of claims 1, 2, 3 and 4, wherein the second rotation detection unit is an optical, magnetic, electromagnetic induction, capacitance or other type of rotation detector.

6. A redundant encoder according to any one of claims 1, 2, 3 and 4, characterized in that the resolution of said second rotation detection unit is 1 / 4096 rotation or less.

7. A redundant encoder according to any one of claims 1, 2, 3 and 4, characterized in that a rotation angle T1s within one rotation with a resolution of 1 / 2 rotation or less is detected from the rotation amount T1 obtained by the first rotation detection unit, and a multiple rotation amount T1m is detected by integrating this rotation amount T1, and a rotation angle T2s within one rotation with a resolution higher than that obtained by the first rotation detection unit is detected from the rotation angle T2 obtained by the second rotation detection unit, and a multiple rotation amount T2m is detected by integrating this rotation angle T2.

8. A redundant encoder according to claim 7, characterized in that by comparing the rotation angle T1s with the rotation angle T2s, the rotation angle within one rotation is detected with redundancy that matches to a resolution of 1 / 2 rotation or less, and by comparing the amount of multiple rotations T1m with the amount of multiple rotations T2m, the amount of multiple rotations is detected with redundancy that matches to a resolution of one rotation.

9. The redundant encoder according to claim 7, wherein the second rotation detection unit and the second signal processing circuit are provided with external power supplies, the resolution of the second rotation detection unit is 1 / 4096 rotation or less, by comparing the rotation angle T1s with the rotation angle T2s, the rotation angle within one rotation is detected to 1 / 4096 rotation or less which is the resolution of the rotation angle T2, and is detected with redundancy up to 1 / 2 rotation or less which is the resolution of the rotation amount T1, and by comparing the multi-rotation amount T1m with the multi-rotation amount T2m, the multi-rotation amount is detected with redundancy that matches up to the resolution of one rotation.

10. A redundant encoder according to claim 8 or 9, further comprising a comparison means for comparing said rotation angle T1s with said rotation angle T2s.

11. A redundant encoder according to claim 8 or 9, further comprising a comparison means for comparing the amount of multiple rotations T1m with the amount of multiple rotations T2m.

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