JP2003075190A - Rotation sensor, actuator therewith, and method of detecting rotation - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a low-cost sensor excellent in service life and stability and simple in structure. SOLUTION: The sensor has a rotating member 2 with a recording member 5 enabling information to be freely rewritten, an information recording means 3 for recording different information on the recording part 5 of the rotating member 2 depending on the direction of rotation, and at least two sensors 4 for detecting the information recorded on the rotating member 2. The direction of rotation of the rotating member 2 from a reference position is detected from the information recorded on the rotating member 2. The recording part 5 is, for example, a magnetic body, and the information recording means 3 is, for example, a permanent magnet that magnetizes the magnetic body with different polarities depending on the direction of rotation.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a rotation detecting sensor, an actuator having the same, and a rotation detecting method. More specifically, the present invention relates to an improvement in the configuration of a rotation detection sensor that detects position information and a circumferential position of a rotating body by obtaining position information from a magnetized area provided on the peripheral surface or main surface of the rotating body. .

[0002]

2. Description of the Related Art A motor for detecting the amount of rotation or direction of a rotor (which may be referred to as the body of the rotor in this specification) and returning it to a reference position is used in an actuator of a robot arm or the like. However, if the rotor can rotate 360 degrees or more, the body of the rotor becomes the same as the reference position every 360 degrees rotation, so it may be in the state of returning to the reference position or 360 degrees extra from the reference position. It may not be possible to determine whether it is rotated. In such a case, it may be difficult to restore the angle or shape of the robot arm to the initial state or protect the cord connected to the rotating member from twisting.

For this reason, it is necessary for the rotation detection sensor of the motor to have a function of determining whether the rotation amount is 0 degree or 360 degrees even if the rotor is at the same reference position, that is, whether the body is uneven. , To ensure this function 3
There is a need for a principle of storing whether or not 0 degree is obtained by rotating 60 degrees. As an actual rotation detection sensor, four methods are mainly used: a battery backup type shown in FIG. 12, a mechanical type (deceleration type) shown in FIG. 13, a magnetic bubble type shown in FIG. 14, and a mechanical switch type shown in FIG. Can be seen.

In the battery backup type, the rotation sensor itself is not turned off so that the integrated value is kept constant, and mechanically 3 including one pulse per rotation.
By turning 60 degrees, it looks exactly the same and the amount of rotation is stored electrically. In this system, for example, an MR element 102 and a fixed magnet 103 are provided in the vicinity of the rotor 101, and the power supply for the detection and the storage circuit for the detection itself is in the supply state even after the main power supply is cut off by the battery.

As the mechanical type, the reduction gear 10
The basic memory mechanism is that the mechanical appearance is different even with multiple rotations by providing 4. In this case, even if multiple rotations are made by mechanically decelerating, it is set within one rotation after deceleration, and the rotation of the input shaft 105 is detected by detecting the angle after deceleration. The rotation detecting means is, for example, the light source 106 and the phototransistor 107.

The magnetic bubble method of (1) is magnetically stored by moving a magnetic domain, and the fact that the permanent magnet 108 on the rotor 101 passes over the magnetic bubble substrate 109 shifts the magnetic bubble is used. is doing.

The mechanical switch type is provided with, for example, a projection 110 and a limit switch 111, and can be basically considered as a reduction gear having one rotation and one tooth, and is memorized by a mechanical body. .

[0008]

However, since it relies on a battery, which has a short life, it requires a circuit and a battery.

Since the mechanical type of (1) involves mechanical contact, there is a concern about the life and stability at high speed rotation and high frequency rotation.

Further, since is a non-contact type and it is an ideal method because it is a memory of the material itself, a special material called a magnetic bubble is required, and its reading requires a complicated circuit. The cost is generally high and the mechanism is complicated.

And, a configuration similar to
It may include the same problem as.

Therefore, the present invention is excellent in life and stability,
An object is to provide a rotation detection sensor having a simple structure and low cost, an actuator having the same, and a rotation detection method.

[0013]

In order to achieve the above object, the inventors of the present invention have made various studies and attached a magnetic substance magnet material (magnetized portion) capable of overwriting magnetization information to the rotor, It was discovered that over-rotation can be detected by attaching a fixed permanent magnet to the stator (stator) and marking with the permanent magnet while rotating the rotor, that is, changing the magnetized state of the magnetized portion. It was It has also been discovered that, by the same principle, over-rotation can be detected even if it is other than magnetism.

The present invention is based on such knowledge, and the rotation detecting sensor according to the first aspect of the present invention includes a rotating member having a recording unit in which information can be freely rewritten, and the recording unit of the rotating member according to the rotation direction. An information recording unit that records different information and at least two detection sensors that detect the recording information of the rotating member are provided, and the rotation direction of the rotating member from the reference position is detected by the recording information of the rotating member.

According to this rotation detecting sensor, different information can be written in the recording portion when the rotating member rotates in one direction and when it rotates in the opposite direction. Therefore, the rotation can be detected by detecting the recorded content. It is possible to determine which side the member is rotating from the reference position. Further, when the rotating member rotates more than a predetermined amount, the recorded contents are biased to some information. Therefore, by detecting this bias, it is possible to discriminate the over-rotation and the over-rotation direction.

According to a second aspect of the present invention, in the rotation detecting sensor according to the first aspect, the recording portion is a magnetic body, and the information recording means magnetizes the recording portion of the rotating member with different polarities depending on the rotation direction. It is a permanent magnet to be performed, and at least two detection sensors are arranged at a predetermined interval to detect the rotation direction of the rotating member from the reference position.

In this rotation detecting sensor, when the rotating member rotates in one direction, the magnetic material on the rotating member is magnetized to one polarity (for example, N pole) by the permanent magnet, while when rotating in the opposite direction, different magnetic properties are obtained. It is magnetized (for example, the S pole).
Therefore, it is possible to determine which side the rotating member is rotating from the reference position by detecting the magnetization record of the magnetic body. Also, if the rotating member rotates more than a predetermined amount, most or all of the magnetic material will be magnetized to have either polarity. Therefore, by detecting this deviation, the direction of over-rotation and over-rotation can be detected. To detect.

According to a third aspect of the present invention, in the rotation detecting sensor according to the second aspect, positive and negative information in the rotation direction from the reference position of the rotating member and a reference point detecting sensor for detecting the positive and negative information are provided. is there. Therefore, the rotating member can be returned to the predetermined position based on the reference point, that is, the positive / negative transition point information.

The permanent magnet in the rotation detecting sensor according to claim 2 is preferably a magnet having four polarizations or a combination of polarized magnets as in the invention according to claim 4.

According to a fifth aspect of the present invention, in the rotation detecting sensor according to any one of the second to fourth aspects, the two detecting sensors are arranged at positions facing each other with the rotation center of the rotating member interposed therebetween, and the permanent magnet is It is arranged substantially in the middle between the two detection sensors and at a position facing the rotating member. In this case, because the detection sensor, the permanent magnet, and the detection sensor are lined up every 90 degrees around the rotating member,
Polarity of magnetization recording detected by both detection sensors when the rotating member rotates 3/4 (3/4) in either direction and at least 3/4 of the magnetic material is magnetized to either polarity. Are equal to each other, and the opposite polarities are detected by both detection sensors if the rotation is performed in the opposite direction by 3/4. Therefore, it is possible to determine from the detection information of both detection sensors whether or not the rotary member is within the rotation range of ± 3/4 rotation (that is, one and a half rotations).

Further, in the rotation detecting sensor according to claim 3, as in the invention according to claim 6, from the detection signals H1 and H2 by the two detecting sensors and the detection signal H3 by the reference point detecting sensor, H1 <> H2 then H3 H1 = H2 then H1 It is possible to detect in which direction the rotating member is rotating from the reference point based on the result obtained based on the logical expression 1.

Further, in the invention described in claim 6, as in the invention described in claim 7, the detection sensor and the reference point detection sensor are monitored, and H3 <> H3Z- ¹ And H1 <> H2 And H3 <> ( The reference point can be detected by the result obtained based on the logical expression 2 of the logical expression 1 at the time of starting the origin return.

According to an eighth aspect of the present invention, in the rotation detection sensor according to the third aspect, means for determining whether or not the reference point can be returned to the origin based on the information obtained from the detection sensor and the reference point detection sensor, and the origin return. When it is difficult, it is provided with means for notifying the outside. Therefore, if it is determined that the reference point can be returned to the origin, the automatic return of the rotating member can be performed more safely.

According to a ninth aspect of the present invention, in the rotation detecting sensor according to the third aspect, the rotating member is provided with a half-divided annular magnetized region having a central angle of 180 °, and a boundary between the magnetized region and the non-magnetized region. Is used as a reference position. In this case, a clear reference position can be obtained from the boundary using the magnetic force. Further, an accurate reference position can be obtained every time the rotating member rotates 180 degrees.

According to a tenth aspect of the present invention, in the rotation detecting sensor according to the third aspect, the reference position is a slit provided on the rotating member, and the reference point detecting sensor is an optical sensor for detecting the slit. To do. In this case, the rotating member is provided with a light blocking region and a light passing region of approximately 180 degrees,
The boundary signal between the light shielding area and the light passing area is used as reference point information. Similar information can be obtained even if the light-shielding and light-passing regions are reflected or non-reflected.

An actuator according to an eleventh aspect of the present invention has the rotation detecting sensor according to any one of the first to tenth aspects, and detects the rotation direction of the rotating member from the reference position. . In this case, it is possible to determine which side the rotating member is rotating from the reference position by detecting the information recorded in the magnetic material (recording unit) of the rotating member, and the rotating member exceeds a predetermined amount. When the rotating member rotates, it is possible to determine that the rotating member rotates more than a predetermined amount by detecting the recording bias in the magnetic body (recording unit).

The rotation detecting method according to the invention of claim 12 is
A rotating member is provided with a recording unit in which information can be rewritten freely, and different information is recorded in the recording unit of the rotating member according to the rotation direction,
The detection information of the rotating member is detected by the detection sensor, and the rotation direction of the rotating member from the reference position is detected based on the recording information of the rotating member.

According to this rotation detection method, different information can be written in the recording portion when the rotating member rotates in one direction and when it rotates in the opposite direction. Therefore, by detecting the recorded content, the rotation can be performed. It is possible to determine which side the member is rotating from the reference position. Further, if the rotating member rotates more than a predetermined amount, the recorded content is biased to some information, and thus it is possible to determine that the rotating member is rotating more than the predetermined amount by detecting this bias. it can.

According to a thirteenth aspect of the present invention, in the rotation detecting method according to the twelfth aspect, the recording portion is a magnetic body, and the permanent magnet magnetizes the recording portion of the rotating member with different polarities depending on the rotation direction. The rotation direction of the rotating member from the reference position is detected by at least two detection sensors arranged at a predetermined interval.

In this rotation detection method, when the rotating member rotates in one direction, the magnetic material on the rotating member is magnetized to one polarity (for example, N pole) by the permanent magnet, while when rotating in the opposite direction, different magnetic properties are obtained. It is magnetized (for example, the S pole). Therefore, it is possible to determine which side the rotating member is rotating from the reference position by detecting the magnetization record of the magnetic body. Also, if the rotating member rotates more than a specified amount, most or all of the magnetic material will be magnetized to have either polarity, so by detecting this deviation, the rotating member will exceed the specified amount. It is possible to determine that it is rotating.

[0031]

BEST MODE FOR CARRYING OUT THE INVENTION The structure of the present invention will be described below in detail based on an example of an embodiment shown in the drawings.

1 to 3, the rotation detecting sensor 1 of the present invention is shown.
Indicates. The rotation detection sensor 1 includes a rotating member 2 including a recording unit 5 capable of rewriting information, and a recording unit 5 of the rotating member 2.
An information recording means 3 for recording different information depending on the rotation direction, and a detection sensor 4 for detecting the recording information of the rotating member 2, and the rotation direction from the reference position of the rotating member 2 by the recording information of the rotating member 2. Is to detect.

In the following, as one embodiment of the present invention, a magnetic type rotation detection sensor 1 suitable for application to a motor as an actuator of a robot arm or the like will be described. This rotation detection sensor 1 has a reference position detection function for detecting the reference position of the rotating member 2 and an over-rotation detection function for detecting an over-rotation state of the rotating member 2, and simply returns the original position of the rotating member 2. Instead, the total rotation amount is returned to the initial state and then the original point is returned to protect the cord or the like connected to the rotating member 2 from twisting, or the arm or the like is returned to the initial angle or shape. Is characterized by.

First, the excessive rotation detection function will be described.
In order to ensure this function, the rotation detection sensor 1 of this embodiment
As shown in FIG. 2, a rotor as a rotating member 2 (hereinafter referred to as "rotor 2") and a permanent magnet as information recording means 3 for magnetizing the rotor 2 (hereinafter referred to as "permanent magnet 3").
And a detection sensor 4 for detecting the magnetized state of the rotor 2 by the permanent magnet 3, and at least two detection sensors 4 are arranged at a predetermined interval so as to detect the rotation direction of the rotor 2. I have to.

The rotor 2 is provided with a recording section 5 whose magnetization record is rewritten (overwritten) by the permanent magnet 3. The recording unit 5, for example, is magnetized to the S pole when passing near the N pole of the permanent magnet 3, and is magnetized to the N pole when passing near the S pole, and keeps this magnetized state until the next magnetism is overwritten. And an annular magnetic body (hereinafter referred to as "magnetized ring 6"). The entire rotor 2 may be made of a magnetic material, but in the present embodiment, as shown in FIG. 1, the recording portion 5 is formed by a magnetized ring 6 made of a magnetic material.
The rotor 2 is fitted into the rotor 2 so as to be integrated with the rotor 2 so as to rotate coaxially.

The permanent magnet 3 is a recording head for performing magnetic recording on the recording portion 5 of the rotor 2. The detection sensor 4 is a detection head that reads magnetic information recorded on the recording unit 5 by the permanent magnet 3. The permanent magnet 3 and the detection sensor 4 are
The recording section 5 is arranged at a position facing the circumferential surface of the recording section 5 so that the recording section 5 can be magnetized and the contents can be read. The permanent magnet 3 is arranged such that the N pole and the S pole are aligned in the tangential direction of the rotor 2 as shown in FIG. 2, for example. As shown in the figure, when the S pole is arranged in the clockwise direction as viewed from the N pole, the recording unit 5 of the rotor 2 is
Is rotated clockwise, the S pole is magnetized to the N pole as shown in black in FIG. 2. On the contrary, when the rotor 2 is rotated counterclockwise, the N pole of the permanent magnet 3 causes white in the figure. It is magnetized to the S pole as shown by being removed.

In this embodiment, a Hall element is used as the detection sensor 4 for detecting the magnetized recording (hereinafter referred to as "Hall element 4"). In this embodiment, as shown in FIG. 2, two Hall elements 4a and 4b are provided every 180 degrees, and are arranged opposite to each other with the center of the rotation detection sensor 1 in between. The permanent magnet 3 described above is arranged at a position different from those of the Hall elements 4a and 4b (for example, a right angle position as shown in the drawing).

Next, the reference position detecting function for detecting the reference position of the rotor 2 will be described. Rotation detection sensor 1
Uses the reference point information 7 formed on the rotor 2 and the reference point detection sensor 8 for detecting the reference point information 7 to return the rotor 2 to the origin based on the reference point. As shown in FIG. 3A, in the present embodiment, an annular magnetic body (hereinafter referred to as a “magnet”) is magnetized into N and S poles every 180 degrees and is provided coaxially with the magnetized ring 6 described above. (Referred to as “ring 9”) is used as the reference point information 7 at the boundary portion between the north pole and the south pole of the magnet ring 9. No information recording means (for example, a permanent magnet) is provided around the magnet ring 9, and the magnetization information of the magnet ring 9 is only detected and is not changed. Similar to the magnetized ring 6, the magnet ring 9 is integrally provided with the rotor 2 so as to rotate by the same amount. Note that, here, the N-pole magnetized region of the magnet ring 9 (hereinafter referred to as the “recording portion 10”) has a semicircular shape with a central angle of 180 degrees, but this range is not limited to this. Also,
The magnet ring 9 may be divided into a magnetized area and a non-magnetized area, and the magnetized area may be used as the recording unit 10.

A reference point detection sensor 8 for detecting magnetic information of the magnet ring 9 is attached so as to face the recording surface of the magnet ring 9. As the reference point detection sensor 8, a Hall element is used as in the above-mentioned detection sensor (hereinafter referred to as "Hall element 8").

FIG. 1 shows an arrangement example of the above-mentioned two rings (magnetized ring 6 and magnet ring 9), Hall elements 4 and 8, and permanent magnet 3. The positional relationship between the Hall elements 4 a and 4 b with respect to the permanent magnet 3,
The magnetizing angle of the recording unit 10 can be variously changed in accordance with the positional relationship between the a and 4b and the Hall element 8 on the side of the magnet ring 9, but in the present embodiment, the Hall element 4a, A preferred arrangement example is shown in which the permanent magnet 3 and the Hall element 4b are arranged every 90 degrees. Such an arrangement is preferable in that the direction of the over-rotation (over-rotation) state can be obtained without rotating by rotating the signals from the two Hall elements 4a and 4b by a simple logical operation.

[0041]

EXAMPLE FIG. 5 shows an example of computer simulation of the operation of the rotation detection sensor 1 according to this embodiment. The permanent magnet 3 and the Hall element 4 were simulated as spot magnets and point detectors. The numbers in the left text box 11 in FIG. 5 are for inputting or indicating the relative movement angle of the rotor 2, and the left picture box 12 shows the magnetized state at that time. On the other hand, the right picture box 14 shows the state of the magnet ring 9 with one rotation and two poles, and the detected value is displayed in black as it is.

The central picture box 13 shows the detection state by the Hall element 4, and is divided into three vertically and three vertically long regions lined up in the left-right direction are formed. Of these, when the same level is detected in both the Hall elements 4a and 4b in the detection state of the magnetized ring 6 on the left side, the detection level is displayed in black, and when different levels are detected, it is displayed in white. Is displayed. In the central part, the logically synthesized one is displayed, and the logics shown in the following formulas 1 and 2 are calculated (logical formula 1). In the equation shown below, the detection signals from the Hall elements 4a and 4b are H1,
It is shown by H2, and the detection signal by the hall element 8 is shown by H3.

[Equation 1] H1 <> H2 then H3

## EQU00002 ## H1 = H2 then H1 In FIG. 5, rotations of. +-. 180 degrees or more appear at three places, but it is understood that the central part of the central picture box 13, which is the conclusion of detection, is normally detected. Similarly, an example in which the operation is over-rotated more is also shown in FIG.

From the above, it can be understood that the rotation detection sensor 1 reliably detects whether or not over-rotation has occurred when the rotor 2 makes such a forward and backward movement. When returning to the origin when exceeding 180 degrees, the same sign signals of H1 and H2, which are the signals of exceeding 180 degrees, are first negated (the detection signal is off), and then the magnet ring 9 It is also an important factor that the position where the polarity inversion occurs is the origin position.

When the rotation is further increased and the operation is performed by ± 270 degrees or more, the result is as shown in FIG. 6, and an erroneous detection occurs when the reverse rotation (return operation) after the rotation turns 90 degrees (in the figure, an ellipse indicates a circle). Enclosed part). As described above, the erroneous detection does not occur at the time of over-rotation, and the erroneous detection occurs in the subsequent reversing operation, which is a feature of the rotation detection sensor 1 of the present embodiment processed only by the mathematical formulas 1 and 2.

Next, the state of the detection sensor 4 during the origin return and the origin return from within ± 360 degrees will be described. The direction of return to origin is represented by the conditions described above. That is, in the normal case, that is, in the case where it does not exceed ± 270 degrees, Equation 1,
Although it has been confirmed in FIGS. 5 and 6 that the problem does not occur in the logical expression 1 shown in the mathematical expression 2, the following will consider the state of each sensor during the return when performing the origin return operation. Here, the initial state of the magnetized ring 6 is divided by 180 degrees around the origin, that is, the initial state of FIGS. 5 and 6 is considered. Suppose that after rotating from 270 degrees to 360 degrees from this state, it returns in the opposite direction. Considering the angle returned here and the angle rotated to return, Equation 1
Let's try to simulate the case where the origin return is performed based on. Further, here, as the condition for the normal point return to be completed, the logical expression (logical expression 2) showing the origin detection conditions as the mathematical expressions 3 to 5 is assumed.

H3 <> H3Z ⁻¹ ; the output of H3 is inverted and

[Expression 4] And H1 <>H2; not in the over-rotation state

[Expression 5] And H3 <> (Equation 1,
2) ； The direction of the H3 edge matches the origin return direction.

The following logical expression condition is defined as "confused" (logical expression 3).

(Expression 6) (Detection direction according to logical expression 1) <> (logical expression 1
Detection direction by Z · ⁻¹ ) This is simply detection of a situation in which the determination of the logical expression 1 is reversed before the origin is detected.

Based on this, FIG. 7 shows a change in the detection state when the operation is once performed from a position of -270 degrees or more.

As can be said from these tables, when 270 degrees is exceeded, or when there is a history of excess, 1) When the origin return cannot be performed, the confusion state is always detected from the logical expression 3. 2) The origin may be detected even with the excess history, but in this case, the excess history is lost and the normal state is restored. 3) By storing and judging the sensor state at the time of starting the origin return and the change in the sensor state after that, the angle at which the confusion occurs can be roughly known. That can be said.

Considering this result from the application side,
1) is ± 27 by performing the confusion detection using the logical expression 3.
It is possible to detect when the origin cannot be restored when the history has exceeded 0 degrees, and it can be applied as error detection. 2)
From the above, it is understood that when the magnetized ring 6 is initialized, the magnetized ring 6 is rotated 180 degrees in the + direction from the origin position by H3 and further rotated 360 degrees in the minus direction from there. Further, from 3), when the state where the confusion is detected is detected, the state of change of H1 to H3 leading to that state is shown in FIG.
By analyzing according to FIG. 8, it is possible to perform the re-initialization and the origin return, and it is possible to automatically and surely perform the origin return even in the operation range of ± 360 degrees.

In addition, from FIG. 7 and FIG. 8, it is necessary to consider the problem of whether or not all patterns are evaluated. That is, 360 degrees or less, 270
Let's think about the operation during power shutoff when stopping at a certain angle, going back and forth within a range that does not exceed this from the time when it rotated more than a degree. FIG. 9 shows an example of how the magnetized ring 6 in this case is magnetized. As you can see, only the over-rotation of 270 degrees or more, which is the initial rotation, is related to the position where the home position return is finally started. As a result, the magnetized state is the same unless the range indicating "rotated" is exceeded.

Further, FIG. 9 shows an actual operation in the case of exceeding 270 degrees, after shaking once up to 330 degrees, and then -1 at the top of the figure.
The change in the magnetized state is shown when the result is 280 degrees as a result of shaking at 00, +90, -30, +40, and -50 degrees. On the other hand, in the lower part of the figure, after shaking up to 330 degrees, 2
The magnetized state when moved to a point of 80 degrees is shown. Here, the point of magnetization change = polarity change point is determined at the time of once swinging up to 330 degrees, and the position of the polarity change point of magnetization is attached unless the operating range of going back and forth exceeds this 330 degree. It remains fixed to the magnetic ring 6 and its relative position does not change. From this, it can be said that the movement back and forth does not change the magnetized state unless the maximum overshoot point is exceeded.

That is, the sensor change of FIGS. 7 and 8 is ± 27.
It is considered to represent all of the origin return process having a history of exceeding 0 degree and within ± 360 degrees.

(In case of over ± 360 degrees) Up to here, ± 36
The result that the origin return in the case of 0 degree, that is, two rotations of the movable region, can be logically achieved was obtained. Now, let's consider what kind of response will be given to the history of further rotation. Similar to FIGS. 7 and 8, the place (angle) in the case of confusion is also examined. The result is shown in FIG. Although the simulation is performed only on the minus side, as is clear from FIGS. 7 and 8, and because the logic of the object of rotation is discussed, the plus side is replaced with H1 and H2, and + and-signs. It is clear that the reversal of is completely equivalent.

(Origin Return) Here, through consideration of FIGS. 7 and 10, it will be examined whether or not the origin can be returned for the case of super 270 degrees and the case of super 360 degrees.

(I) When the history is within ± 270 degrees or less, "confusing" does not occur, and the origin can be directly returned to and ended.

(Ii) A pattern whose history is ± 270 to ± 360 degrees or more, a pattern of ± 360 to ± 450 degrees (in this case,
Even if the history has an absolute value that exceeds at least 270 degrees), if "confused" does not occur, even if the return to origin is terminated, the change in the magnetized state after that is the same as after return to origin in the case of. Fits in

(Iii) In a pattern whose history is ± 270 to ± 360 degrees or more, or ± 360 to ± 450 degrees,
If "conflict" occurs during the return to origin, take the method of (ii). The position where the confusion occurs is estimated from the change in the sensor status, the required amount of feed is applied, the position is moved to the position of (ii), and the origin is returned.

Here, (iii) will be described in detail. Again, we will discuss on the negative side. If the position where the confusion occurs can be grasped in units of 90 degrees, it is possible to turn the rotor 2 to the position of the pattern of (ii) and perform the origin return again by swinging the minimum moving distance.
This is the fastest time to return to origin. (i
The point of the pattern i) is to forcibly return 90 degrees or more in absolute angle to the side opposite to the direction in which the history is over. This is exactly the same as the initialization operation. It is important to note here that this forced return angle should not exceed 270 degrees. In summary, the origin can be returned and the magnetized state can be corrected by forcibly moving it to the range of ± 90 to ± 270 degrees opposite to the direction in which there is history.

In order to obtain the angle to be forcibly moved, FIG. 11 is a summary of the points that cause confusion for each change in the detection pattern of the sensor from FIGS. As you can see from this figure, the angle that should be forcedly rotated is within the specified range, and -2
It is possible to bring to two regions of 70 to -360 degrees and -360 to -450 degrees, in which the origin can be returned to the origin without any problem even if the depth of history is different. However, if it falls within the predetermined range and sensor error etc. is included, it is fully expected that it will not fall within the calculated range just by swinging the specified angle in an open loop manner.

Now, returning to FIGS. 7 and 8 again and looking at the sensor patterns capable of returning to the origin, the patterns capable of returning to the origin are the same, and H1, H2 at the start position are the same.
There are two types of patterns of H3, ++ and ++. Of these, ++ is also included in the start pattern where “confused” occurs, so if it is the ++ − pattern, it can be determined that it is within the range of +180 to +270 degrees.
The home position can be returned as it is.

As described above, according to the rotation detection sensor 1 of the present embodiment, (1) the origin return direction is judged by the logical expression 1 to start the origin return, and the logical expressions 1 to 3 are executed during the origin return. to continue. (2) In this case, if the return-to-origin is completed by the logical expression 2, then it is completed. (2) 'When "confused" is detected by the logical expression 3, the direction to be forcibly returned is determined by collating with FIGS. 7 and 8 showing the sensor state during the origin return. (3) If the minus side over history side matches, H
Turn it to the plus side until the detection values of 1, H2, H3 become ++-(3) 'If it matches the plus side over history side, H
Turn to the minus side until the detected values of 1, H2, H3 become-+. (4) Return to (1) and perform home return again. In this case, it is considered that (2) will always occur and (2) 'will not occur, and the home return will end.

The above-described embodiment or example is an example of the preferred embodiment of the present invention, but the present invention is not limited to this, and various modifications can be made without departing from the gist of the present invention. For example, in the present embodiment, the recording unit 5 provided on the rotating member (rotor) 2 side is rotated with respect to the detection sensor (Hall element) 4 fixed on the stator side to overwrite the magnetized recording. Need only relatively change the position. For example, conversely to this, the information recording means 3 and the detection sensor 4 are fixed to the fixed recording unit 5.
Even if is provided so as to rotate around the recording unit 5, it is possible to detect the rotation direction and the excessive rotation as in the present embodiment.

In this embodiment, the case where magnetism is used as a suitable means for recording information in the recording portion 5 of the magnetized ring 6 has been described, but the recording means is not particularly limited to this, and the magnetic means is not limited to this. Information recording means 3 as in the case of using
It is possible to use any means capable of successively overwriting a portion facing each other, for example, a device for overwriting a heat-sensitive material and capturing the image to determine.

[0064]

As is apparent from the above description, according to the rotation detecting sensor of the first aspect, different information is recorded in the recording portion when the rotating member rotates in one direction and when it rotates in the opposite direction. By writing and detecting the recorded contents, it is possible to determine which side the rotating member is rotating from the reference position. Further, if the rotating member rotates more than a predetermined amount, the recorded content is biased to some information, and thus it is possible to determine that the rotating member is rotating more than the predetermined amount by detecting this bias. it can.

Therefore, according to this rotation detecting sensor, not only the rotary member can be returned to the original point, but also the total amount of rotation can be returned to the initial state and then the original point can be returned. Therefore, the cord or the like connected to the rotating member can be protected from being twisted, or the arm or the like can be returned to the initial angle or shape.

According to the rotation detecting sensor of the second aspect, it is possible to determine which side the rotating member is rotating from the reference position by detecting the magnetization record of the magnetic material. Also, if the rotating member rotates more than a specified amount, most or all of the magnetic material will be magnetized to have either polarity, so by detecting this deviation, the rotating member will exceed the specified amount. It is possible to determine that it is rotating.

Moreover, by adopting a simple structure with no power supply and no contact, the life and stability can be improved, and the Hall element,
Since it can be made up of inexpensive and simple members such as permanent magnets and magnetic materials, it is easy to realize low cost.

According to the rotation detecting sensor of claim 3,
Since the reference point information formed on the rotating member and the reference point detection sensor for detecting the reference point information are provided, the rotating member can be returned to the predetermined position based on the reference point information.

According to the rotation detecting sensor of the fourth aspect, since the permanent magnet is a magnet having four polarizations or a combination of polarized magnets, for example, as shown in FIG. The magnetic flux for recording can be effectively induced to the magnetized portion with respect to the polarized light.

Further, according to the rotation detection sensor of the fifth aspect, the detection sensor, the permanent magnet and the detection sensor are arranged around the rotating member at intervals of 90 degrees. Therefore, based on the detection information of both detection sensors. Rotating member is ± 3/4 rotation (1
It is possible to determine whether or not it is within a rotation range of 2.5 rotations at the maximum.

According to the rotation detecting sensor of the sixth aspect, the detection signals H1 and H2 from the two detecting sensors are
It is possible to detect in which direction the rotating member is rotating from the reference point based on the result obtained based on the logical expression from the detection signal H3 from the reference point detection sensor.

Further, according to the rotation detecting sensor of the seventh aspect, the detection sensor and the reference point detecting sensor can be monitored, and the reference point provided on the rotating member can be detected by the result obtained based on the logical expression. .

According to the rotation detecting sensor of the eighth aspect, if it is determined that the reference point can be returned to the origin, the automatic return of the rotating member can be performed more safely.

According to the rotation detecting sensor of the ninth aspect, the rotating member is provided with a half-divided annular magnetized area having a central angle of 180 degrees, and the boundary signal between the magnetized area and the non-magnetized area is used as the reference point information. Since it is used as, clear reference point information can be obtained. Also, accurate reference point information can be obtained every time the rotating member rotates 180 degrees.

According to the rotation detecting sensor of the tenth aspect, it is possible to obtain clear reference point information by using the optical sensor.

Since the actuator according to claim 11 has the rotation detecting sensor according to any one of claims 1 to 10, the actuator is rotated by detecting the information recorded in the magnetic body (recording section) of the rotating member. It is possible to determine to which side the member is rotating from the reference position, and if the rotating member has rotated beyond a specified amount, a magnetic material (recording unit)
It is possible to determine that the rotating member is rotating more than a predetermined amount by detecting the recording bias in (1).

According to the rotation detecting method of claim 12,
Since different information can be written in the recording unit when the rotating member rotates in one direction and when rotating in the opposite direction, by detecting the recorded contents, the rotating member can be positioned on either side of the reference position. It is possible to determine whether it is rotating. Further, if the rotating member rotates more than a predetermined amount, the recorded content is biased to some information, and thus it is possible to determine that the rotating member is rotating more than the predetermined amount by detecting this bias. it can.

According to the rotation detecting method of the thirteenth aspect, it is possible to determine which side the rotating member is rotating from the reference position by detecting the magnetization record of the magnetic material. Also, if the rotating member rotates more than a specified amount, most or all of the magnetic material will be magnetized to have either polarity, so by detecting this deviation, the rotating member will exceed the specified amount. It is possible to determine that it is rotating.

[Brief description of drawings]

FIG. 1 is a perspective view of a rotation detection sensor according to an embodiment of the present invention.

FIG. 2 is a plan view of a sensor showing an excessive rotation detection function of the rotation detection sensor.

FIG. 3 is a plan view of a reference position detecting function portion of (A) a rotation detecting sensor;
(C) It is a front view of the excessive rotation detection function part.

FIG. 4 is a schematic perspective view of a magnetized ring and a permanent magnet showing a second embodiment of the present invention.

FIG. 5 is a diagram for explaining an embodiment of the present invention, showing an operation in a range in which normal detection is performed.

FIG. 6 is a diagram showing an operation after exceeding 270 degrees.

FIG. 7 is a diagram showing an operation and logical expressions 2 and 3 after exceeding -270 degrees.
9 is a table showing a relationship with (exceeding − direction).

FIG. 8: Operation after exceeding +270 degrees and logical expressions 2 and 3
It is a table which shows the relationship with (+ direction excess).

FIG. 9 is a diagram showing an example of a magnetized state of a magnetized ring during power-off.

FIG. 10 is a diagram showing an operation and a logical expression 2 after exceeding -270 degrees.
It is a table | surface which shows the relationship with 3 (-direction excess).

FIG. 11 is a table summarizing points where confusion occurs for each change in the detection pattern of the rotation detection sensor.

FIG. 12 is a schematic view showing a conventional battery backup type rotation detection sensor.

FIG. 13 is a schematic diagram showing a conventional mechanical (deceleration) rotation detection sensor.

FIG. 14 is a schematic view showing a conventional magnetic bubble type rotation detection sensor, (A) is a perspective view and (B) is a partial plan view.

FIG. 15 is a schematic view showing a conventional mechanical switch type rotation detection sensor.

[Explanation of symbols]

1 Rotation detection sensor 2 Rotor (rotating member) 3 Permanent magnet (information recording means) 4 Hall element (detection sensor) 5 recording section 7 reference point information 8 Hall element (reference point detection sensor) 9 Magnet ring (magnetic material)

   ─────────────────────────────────────────────────── ─── Continued front page    (72) Inventor Haruhiro Tsuneda             2 Stock Association at 10801 Hara-mura, Suwa-gun, Nagano Prefecture             Inside Sanwa Seiki Seisakusho Suwa Minami Factory F term (reference) 2F077 CC02 JJ01 JJ08 JJ23 TT06                       TT51 TT62

Claims (13)

[Claims] 1. A rotating member provided with a recording unit in which information can be freely rewritten, information recording means for recording different information in the recording unit of the rotating member according to a rotation direction, and recording information of the rotating member is detected. And at least two detection sensors,
A rotation detecting sensor for detecting a rotation direction of the rotating member from a reference position based on the record information of the rotating member. 2. The recording section is a magnetic body, and the information recording means is a permanent magnet that magnetizes the recording section of the rotating member with different polarities according to the rotation direction, and the detection sensor is arranged at predetermined intervals. 2. The rotation detection sensor according to claim 1, wherein at least two of the rotation detection sensors are arranged at a predetermined position to detect the rotation direction of the rotation member from the reference position. 3. The rotation detecting sensor according to claim 2, further comprising: positive / negative information in a rotation direction of the rotating member from a reference position and a reference point detecting sensor for detecting the positive / negative information. 4. The rotation detecting sensor according to claim 2, wherein the permanent magnet is a magnet having four polarizations or a magnet in which polarized magnets are combined. 5. The two detection sensors are arranged at positions facing each other with the center of rotation of the rotary member interposed therebetween, and the permanent magnet is at a position approximately midway between the two detection sensors and facing the rotary member. 5. The rotation detection sensor according to claim 2, wherein the rotation detection sensor is arranged in. 6. A detection signal H by the two detection sensors.
1, H2 and the detection signal H3 by the reference point detection sensor
4. The direction obtained from the above based on the logical expression 1 of H1 <> H2 then H3 H1 = H2 then H1 is used to detect in which direction the rotating member is rotating from the reference position. Rotation detection sensor. 7. The detection sensor and the reference point detection sensor are monitored to monitor H3 <> H3Z- ¹ And H1 <> H2 And H3 <> (result of logical expression 1 at the time of starting origin return).
7. The rotation detecting sensor according to claim 6, wherein the reference point is detected based on a result obtained based on the logical expression 2 of FIG. 8. Means for determining whether the origin can be returned to the reference point based on the information obtained from the detection sensor and the reference point detection sensor, and means for notifying the outside when the origin return is difficult. The rotation detection sensor according to claim 3, further comprising: 9. The rotating member is provided with a half-divided annular magnetized region having a central angle of 180 degrees, and a boundary between the magnetized region and the non-magnetized region is used as the reference position.
The rotation detection sensor described. 10. The rotation detecting sensor according to claim 3, wherein the reference position is a slit provided in the rotating member, and the reference point detecting sensor is an optical sensor for detecting the slit. 11. An actuator comprising the rotation detection sensor according to claim 1 and detecting a rotation direction of the rotating member from a reference position. 12. A rotating member is provided with a recording unit in which information can be freely rewritten, different information is recorded in the recording unit of the rotating member according to a rotation direction, and the recorded information of the rotating member is detected by a detection sensor, A rotation detecting method comprising detecting the rotation direction of the rotating member from a reference position based on the record information of the rotating member. 13. The recording unit is an annular magnetic body, and the recording unit of the rotating member is magnetized with a different polarity depending on a rotation direction by a permanent magnet, and at least two recording units are arranged at a predetermined interval. 13. The rotation detection method according to claim 12, wherein the detection sensor detects the rotation direction of the rotating member from the reference position.