Positioning device, drive device, positioning method, positioning program

Abstract

The present invention provides a positioning device that can improve the reliability of detecting the position of a movable element moving between two adjacent substrates. [Solution] The positioning device 4 comprises two substrates arranged adjacent to each other along the direction of movement of the movable element C, each of the two substrates having a position detection unit for positioning a positioning scale C attached to the movable element C, and when the positioning scale spans the detection range of the position detection units of each of the two substrates, and the positioning unit of the positioning scale C is switched from the source position detection unit on the opposite side of the direction of movement to the destination position detection unit on the direction of movement side, at least one count value including the first count value counted after the switch is output from the destination substrate to the source substrate.

Description

[Technical Field]

[0001] This disclosure relates to a drive device, etc., for moving a movable element along a track. [Background technology]

[0002] Patent Document 1 discloses a linear transport system as a drive device for moving a movable element along a track. Multiple magnetic sensors arranged along the track measure the position of a magnetic scale attached to the movable element. [Prior art documents] [Patent Documents]

[0003] [Patent Document 1] Japanese Patent Publication No. 2021-164396 [Overview of the project] [Problems that the invention aims to solve]

[0004] One possible approach is to arrange multiple circuit boards along a track and install a magnetic sensor on each of them. In this case, since each of these circuit boards uses different logic circuits such as FPGAs (Field Programmable Gate Arrays) and has a different clock source, the processing timing of two adjacent circuit boards will not be strictly synchronized. Therefore, when a movable element moves between the magnetic sensors of two adjacent circuit boards, it is possible that for a moment, neither circuit board's magnetic sensor may be able to detect the movable element.

[0005] This disclosure is made in view of these circumstances and aims to provide a positioning device, etc., that can improve the reliability of position detection of a movable element moving between two adjacent substrates. [Means for solving the problem]

[0006] To solve the above problems, a positioning device according to an aspect of the present disclosure includes two substrates arranged adjacent to each other along the moving direction of a mover. Each of the two substrates has a position detection unit for positioning a positioning scale attached to the mover. When the positioning subject of the positioning scale straddles the detection ranges of the position detection units of the two substrates, when switching the positioning subject of the positioning scale from the position detection unit at the original position on the side opposite to the moving direction to the position detection unit at the destination position on the moving direction side, at least one count value including the first count value counted after the switching at the position detection unit at the destination position is output from the substrate at the destination position to the substrate at the original position.

[0007] In this aspect, when the positioning subject of the positioning scale of the mover is switched from the position detection unit of the substrate at the original position to the position detection unit of the substrate at the destination position, the substrate at the destination position outputs the count value at the position detection unit at the destination position to the substrate at the original position. Therefore, the substrate at the original position can continue counting using the input count value, so the mover can be detected on at least one of the substrates.

[0008] Another aspect of the present disclosure is a driving device. This device includes a mover driven along a track and two substrates arranged adjacent to each other along the track. Each of the two substrates has a position detection unit for positioning a positioning scale attached to the mover. When the positioning scale straddles the detection ranges of the position detection units of the two substrates, when switching the positioning subject of the positioning scale from the position detection unit at the original position on the side opposite to the moving direction of the mover to the position detection unit at the destination position on the moving direction side, at least one count value including the first count value counted after the switching at the position detection unit at the destination position is output from the substrate at the destination position to the substrate at the original position.

[0009] Yet another aspect of the present disclosure is a positioning method. This method is used in a positioning device including two substrates arranged adjacent to each other along the moving direction of a mover. Each of the two substrates has a position detection unit for detecting a positioning scale attached to the mover. When the positioning scale straddles the detection ranges of the position detection units of the two substrates and the positioning subject of the positioning scale is switched from the position detection unit at the original position on the side opposite to the moving direction to the position detection unit at the destination position on the moving direction side, at least one count value including the first count value counted after the switching at the position detection unit at the destination position is output from the substrate at the destination position to the substrate at the original position.

[0010] Yet another aspect of the present disclosure is a positioning program. This program causes a computer to execute a step of outputting at least one count value including the first count value counted after the switching at the position detection unit at the destination position from the substrate at the destination position to the substrate at the original position when the positioning subject of the positioning scale is switched from the position detection unit at the original position on the side opposite to the moving direction to the position detection unit at the destination position on the moving direction side in a positioning device including two substrates arranged adjacent to each other along the moving direction of a mover. Each of the two substrates has a position detection unit for detecting a positioning scale attached to the mover, and the positioning scale straddles the detection ranges of the position detection units of the two substrates.

[0011] In addition, any combination of the above components, or those obtained by converting these expressions into methods, devices, systems, recording media, computer programs, etc., are also included in the present disclosure.

Advantages of the Invention

[0012] According to the present disclosure, the reliability of position detection of a mover moving between two adjacent substrates can be improved.

Brief Description of the Drawings

[0013] [Figure 1] It is a perspective view showing the overall structure of a linear conveyance system. [Figure 2] A schematic diagram shows a positioning device consisting of a position detection unit and other components in a linear transport system. [Figure 3] Patent Document 1 schematically illustrates how the positioning system of a magnetic scale switches from the source magnetic sensor to the destination magnetic sensor. [Figure 4] This example shows how the positioning primary switching unit controls the switching of each magnetic sensor. [Figure 5] This example shows how the positioning primary switching unit controls the switching of each magnetic sensor. [Figure 6] This example shows how the positioning primary switching unit controls the switching of each magnetic sensor. [Figure 7] This example shows how the positioning primary switching unit controls the switching of each magnetic sensor. [Figure 8] This example shows how the positioning primary switching unit controls the switching of each magnetic sensor. [Figure 9] A schematic diagram shows the multiple circuit boards included in the positioning device. [Figure 10] This diagram schematically illustrates how the magnetic sensor on the source circuit board detects the reference mark on the magnetic scale. [Figure 11] This diagram schematically illustrates how the positioning location of the magnetic scale switches from the magnetic sensor on the source board to the magnetic sensor on the destination board. [Figure 12] This timing chart schematically shows an example of the time-dependent changes in the sensors used on each circuit board, the count values ​​of the magnetic sensors, and the absolute position of the movable element. [Figure 13] This is a timing chart showing a magnified portion of Figure 12. [Figure 14] This is a timing chart schematically showing the time changes of the sensors used, count values, and absolute position of the movable element for each substrate in the embodiment. [Figure 15] This is a timing chart showing an enlarged portion of Figure 14. [Modes for carrying out the invention]

[0014] The following describes in detail the forms for implementing this disclosure (hereinafter also referred to as embodiments) with reference to the drawings. In the description and / or drawings, identical or equivalent components, members, processes, etc., are denoted by the same reference numerals, and redundant descriptions are omitted. The scale and shape of the illustrated parts are set for convenience in order to simplify the description and are not to be interpreted restrictively unless otherwise specified. The embodiments are illustrative and do not limit the scope of this disclosure in any way. Not all features or combinations thereof presented in the embodiments are necessarily essential to this disclosure. For convenience, embodiments are presented by breaking them down into components for each function and / or group of functions that realize them. However, one component in an embodiment may actually be realized by a combination of multiple separate components, and multiple components in an embodiment may actually be realized by a single integrated component.

[0015] Figure 1 is a perspective view showing the overall structure of a linear transport system 1, which is one embodiment of the drive device according to this disclosure. The linear transport system 1 comprises a stator 2 that constitutes an annular rail or track, and a plurality of movable elements 3A, 3B, 3C, 3D (hereinafter collectively referred to as movable element 3) that are driven by the stator 2 and can move along the rail. An electromagnet or coil provided on the stator 2 and a permanent magnet provided on the movable element 3 face each other, thereby forming a linear motor along the annular rail. The rail formed by the stator 2 is not limited to an annular shape and may be any shape. For example, the rail may be straight or curved, one rail may branch into multiple rails, or multiple rails may merge into one rail. Furthermore, the installation direction of the rail formed by the stator 2 is also arbitrary. In the example of Figure 1, the rail is arranged in a horizontal plane, but the rail may be arranged in a vertical plane, or in a plane or curved surface at any angle of inclination.

[0016] The stator 2 has a rail surface 21 whose normal direction is horizontal. The rail surface 21 extends in a strip shape along the direction in which the rail is formed, and when forming an annular rail as in the example in Figure 1, it becomes an endless strip with (virtual) ends connected. Multiple drive modules (not shown) equipped with electromagnets are embedded or arranged continuously or periodically along the rail surface 21, which can form rails of any shape. The electromagnets in the drive modules generate a magnetic field that exerts a propulsive force along the rail on the permanent magnet of the movable element 3 and / or the electromagnet itself. Specifically, when a drive current such as three-phase alternating current is passed through these numerous electromagnets, a moving magnetic field is generated that linearly drives the movable element 3, equipped with a permanent magnet, in a desired tangential direction along the rail. In the example in Figure 1, the normal direction of the rail surface 21 that forms an annular rail in the horizontal plane was horizontal, but the normal direction of the rail surface 21 may be vertical or any other direction.

[0017] In the stator 2, a positioning unit 22 provided on the upper or lower surface perpendicular to the rail surface 21 has multiple magnetic sensors (not shown in Figure 1) embedded continuously or periodically as position detection units capable of measuring the position of a magnetic scale (not shown in Figure 1) attached to the movable element 3 as a positioning target or positioning scale. A magnetic sensor that positions a magnetic scale formed by a striped magnetic pattern or magnetic scale at a constant pitch generally has multiple magnetic detection heads. By shifting the spacing between the multiple magnetic detection heads relative to the pitch or period of the magnetic pattern of the magnetic scale, the magnetic sensor can measure the position of the magnetic scale with high accuracy. In a typical magnetic sensor with two magnetic detection heads, for example, the spacing between the two magnetic detection heads is shifted by 1 / 4 pitch (the phase is shifted by 90 degrees) relative to the magnetic pattern of the magnetic scale. Alternatively, the magnetic sensor may be provided on the movable element 3 and the magnetic scale on the stator 2. Furthermore, the velocity of the movable element 3 can be detected by differentiating the position of the movable element 3 measured by the positioning unit 22 with respect to time, and the acceleration of the movable element 3 can be detected by differentiating that velocity with respect to time.

[0018] The position detection unit provided on the stator 2 and the positioning target or positioning scale attached to the movable element 3 are not limited to the magnetic type described above, but may also be optical or other types. In the case of the optical type, an optical scale formed by a striped pattern or markings at a constant pitch is attached to the movable element 3, and an optical sensor capable of optically reading the striped pattern of the optical scale is provided on the stator 2. In the magnetic and optical types, the position detection unit measures the positioning target (magnetic scale or optical scale) non-contactually, thus reducing the risk of failure of the position detection unit when the object being transported by the movable element 3 is scattered and enters the positioning location (upper surface of the stator 2). However, in the optical type, if the optical scale is covered by the transported object such as liquid or powder that enters the positioning location, the positioning accuracy will deteriorate. Therefore, it is preferable to use the magnetic type, which does not deteriorate the positioning accuracy even if the transported object, whose magnetism is negligible, enters the positioning location.

[0019] The stator 2 comprises multiple substrates (not shown in Figure 1) each having one or more position detection units. The multiple position detection units on the stator 2 are mounted on one of the multiple substrates. The multiple substrates are arranged along the direction of movement of the movable element 3. The position detection units described in Figures 1 to 8 are all examples where they are mounted on a single substrate. Details of the substrates will be described later with reference to Figure 9 and subsequent figures.

[0020] The movable element 3 comprises a movable element body 31 facing the rail surface 21 of the stator 2, a positioned section 32 extending horizontally from the top of the movable element body 31 and facing the positioning section 22 of the stator 2, and a transport section 33 extending horizontally from the movable element body 31 on the opposite side of the positioned section 32 (the side farther from the stator 2) on which the transported object is placed or fixed. The movable element body 31 is equipped with one or more permanent magnets (not shown) facing a plurality of electromagnets embedded in the rail surface 21 of the stator 2 along the rail. The moving magnetic field generated by the electromagnets of the stator 2 applies linear power or thrust in the tangential direction of the rail to the permanent magnets and / or the electromagnets themselves of the movable element 3, so that the movable element 3 is driven linearly along the rail surface 21 relative to the stator 2.

[0021] The positioning unit 32 of the movable element 3 is provided with a magnetic scale or optical scale, which serves as a positioning target or positioning scale, facing the position detection unit (magnetic sensor or optical sensor) provided on the positioning unit 22 of the stator 2. In the example shown in Figure 1, where the position detection unit is provided on the upper surface of the stator 2, the positioning target, such as a magnetic scale, is attached to the lower surface of the positioning unit 32 of the movable element 3. When the positioning unit 22 and the positioning unit 32 are magnetic, it is preferable that the rail surface 21 and the positioning unit 22 of the stator 2 are formed on different surfaces or at separate locations, and that the movable element body 31 and the positioning unit 32 of the movable element 3 are formed on different surfaces or at separate locations, so that the magnetic field between the electromagnet on the rail surface 21 and the permanent magnet on the movable element body 31 does not affect the magnetic positioning of the positioning unit 22 and the positioning unit 32.

[0022] Figure 1 illustrates four movable elements 3A, 3B, 3C, and 3D, but in a linear transport system 1 that transports many small items, for example, it is conceivable that more than 1,000 movable elements 3 may be required.

[0023] Figure 2 schematically shows a positioning device 4 in a linear transport system 1, which is composed of a position detection unit and the like. The positioning device 4 includes a plurality of (four in the illustrated example) magnetic sensors S0 to S3 as position detection units, which are embedded in or arranged in the rail surface 21 along the trajectory direction of the stator 2 or the direction of movement of the movable element C (left and right direction in Figure 2), in order to position a magnetic scale (hereinafter also referred to as magnetic scale C for convenience) which is attached to one or more (one in the illustrated example) movable element C. Hereinafter, when simply referred to as "direction of movement," it means the direction of movement of the movable element C.

[0024] The distance between each magnetic sensor S0 to S3 in the direction of movement may be equal, but in this embodiment, an example where all the distances are different will be described. Specifically, the distance X between the 0th magnetic sensor S0 and the 1st magnetic sensor S1 0 / 1 Let X be 30mm, for example, and the distance between the first magnetic sensor S1 and the second magnetic sensor S2 1 / 2 Let X be 26mm, for example, and the distance between the second magnetic sensor S2 and the third magnetic sensor S3 2 / 3 Let's say the spacing X is 24 mm, for example.0 / 1 and interval X 1 / 2 and interval X 2 / 3 are different from each other. Although it is preferable that the intervals between the magnetic sensors are as constant as possible, it may not be practical to arrange the magnetic sensors at equal intervals at the curved portions, branch portions, merging portions, etc. of the rail. This embodiment is suitable for such cases.

[0025] For the intervals X 0 / 1 of the above magnetic sensors S0 to S3 1 / 2 and X 2 / 3 the length in the moving direction of the magnetic scale C is, for example, 48 mm. Thus, in this embodiment, the intervals (30 mm, 26 mm, 24 mm) in the moving direction of each of the magnetic sensors S0 to S3 are smaller than the length (48 mm) in the moving direction of the magnetic scale C.

[0026] The magnetic scale C has both end portions EL and ER in the moving direction, and a long scale body AB sandwiched between the both end portions EL and ER from both sides in the moving direction. A number of magnetic graduations or magnetic patterns are formed on the scale body AB at equal intervals along the moving direction. Each of the magnetic sensors S0 to S3 that detects the magnetic graduations on the scale body AB outputs common A-phase and B-phase pulses in a linear encoder. Typically, the phases of the A-phase pulses and the B-phase pulses are different from each other by 90 degrees. Note that magnetic graduations similar to those of the scale body AB may also be formed at both end portions EL and ER of the magnetic scale C.

[0027] The length in the moving direction of each of the end portions EL and ER of the magnetic scale C is, for example, 8 mm. In this case, the length in the moving direction of the scale body AB is 32 mm obtained by subtracting the total length of 16 mm of both end portions EL and ER from the length of 48 mm of the magnetic scale C. Thus, in this embodiment, the intervals (30 mm, 26 mm, 24 mm) in the moving direction of each of the magnetic sensors S0 to S3 are smaller than the length (32 mm) in the moving direction of the scale body AB of the magnetic scale C.

[0028] A reference mark Z is provided on the movable element C and / or magnetic scale C as a reference mark. Each magnetic sensor S0 to S3 that first magnetically detects the reference mark Z outputs a Z-phase pulse, which is common in known linear encoders. The Z-phase pulse output in response to the reference mark Z is used to determine the reference position of the movable element C. Specifically, the magnetic sensor that first detects the reference mark Z and first outputs a Z-phase pulse becomes the reference sensor from which the counting unit described later starts counting the A / B phase magnetic scale of the magnetic scale C. The following describes the case where the 0th magnetic sensor S0 is the reference sensor for the magnetic scale C. In the illustrated state, the reference mark Z is on the 0th magnetic sensor S0 which is the reference sensor, and the counting unit 50 of the 0th magnetic sensor S0, which detected the reference mark Z, starts counting the A / B phase magnetic scale of the magnetic scale C from a count value of "0".

[0029] The above description of magnetic scale C also applies to other magnetic scales attached to other movable parts not shown. However, the dimensions of each part and the position of the reference mark are arbitrarily determined for each magnetic scale. Unless otherwise specified below, the description of magnetic scale C also applies to other magnetic scales.

[0030] Each magnetic sensor S0 to S3 is equipped with counting units 50 to 53 that count the A / B phase magnetic scales formed on the scale body AB and / or both ends EL and ER of the magnetic scale C. The direction of increase or decrease of the count value in each counting unit 50 to 53 corresponds to the direction of movement of the magnetic scale C (i.e., the movable element C) detected by each magnetic sensor S0 to S3. For example, when the movable element C moves from left to right in Figure 2, the count value in each counting unit 50 to 53 increases in accordance with the number of A / B phase pulses output by each magnetic sensor S0 to S3, and when the movable element C moves from right to left in Figure 2, the count value in each counting unit 50 to 53 decreases in accordance with the number of A / B phase pulses output by each magnetic sensor S0 to S3.

[0031] As the movable element C moves along the rail, the magnetic sensors S0 to S3 that position the magnetic scale C are switched sequentially. Figure 3 schematically shows how, in Patent Document 1, the positioning main of a magnetic scale C moving from left to right switches from the source magnetic sensor S0 to the destination magnetic sensor S1. As shown in the figure, the switching of magnetic sensors S0 and S1 is performed when the scale body AB of the magnetic scale C straddles the detection ranges of two adjacent magnetic sensors S0 and S1. In the illustrated example, the positioning main of the magnetic scale C switches from magnetic sensor S0 to magnetic sensor S1 when magnetic sensors S0 and S1 are at positions SW1 and SW2 that are symmetrical with respect to the center of the magnetic scale C's direction of movement (the position of the reference mark Z).

[0032] The first switching position SW1 is a position within the scale body AB at a predetermined distance from the boundary between the left end EL and the scale body AB, and the second switching position SW2 is a position within the scale body AB at a predetermined distance from the boundary between the right end ER and the scale body AB. In the illustrated example, the distance from the left end of the scale body AB to the first switching position SW1 and the distance from the right end of the scale body AB to the second switching position SW2 are, for example, 1 mm. In this case, the distance from the center of the scale body AB to the first switching position SW1 and the distance from the center of the scale body AB to the second switching position SW2 are 15 mm, and their sum (30 mm) is the distance X between the magnetic sensors S0 and S1. 0 / 1 This matches.

[0033] When the positioning primary of the magnetic scale C switches from magnetic sensor S0 to magnetic sensor S1, the count value of the counting unit 50 of the source magnetic sensor S0 is carried over to the count value of the counting unit 51 of the destination magnetic sensor S1. In the following, the count values ​​of each counting unit 50 to 53 are considered zero when each magnetic sensor S0 to S3 detects the center of the magnetic scale C (position of reference mark Z), the count values ​​of each counting unit 50 to 53 are considered positive when each magnetic sensor S0 to S3 detects the magnetic scale on the opposite side of the direction of movement of the movable element C from the center of the magnetic scale C (left side in Figure 3), and the count values ​​of each counting unit 50 to 53 are considered negative when each magnetic sensor S0 to S3 detects the magnetic scale on the side of the direction of movement of the movable element C from the center of the magnetic scale C (right side in Figure 3).

[0034] In the illustrated example, the position of the reference mark Z corresponds to a count value of "0", the first switching position SW1 corresponds to a positive count value of "+15,000" corresponding to, for example, the distance to the reference mark Z (15 mm), and the second switching position SW2 corresponds to a negative count value of "-15,000" corresponding to, for example, the distance to the reference mark Z (15 mm). The ratio of the absolute value of the change in the count value (15,000) to the physical distance (15 mm) is also called the sensor resolution R, and in this embodiment, R is kept constant at R = 1,000 (= 15,000 / 15). The count value at the first switching position SW1 is also called the switching count value, and the count value at the second switching position SW2 is also called the starting count value. In the illustrated example, the switching count value and the starting count value differ only in their sign (positive or negative). As shown in the diagram, when the first switching position SW1 of the magnetic scale C is above the magnetic sensor S0, the switching count value "+15,000" of its counting unit 50 is converted to the starting count value "-15,000" of the counting unit 51 of the magnetic sensor S1, which is at the second switching position SW2. From thereafter, the magnetic sensor S1 becomes the primary positioning unit of the magnetic scale C, and its counting unit 51 counts from the starting count value "-15,000" up to the switching count value "+15,000" for the next magnetic sensor.

[0035] As described above, the technology described in Patent Document 1, in which the count value is reversed ("+15,000" → "-15,000") when switching between magnetic sensors S0 and S1, assumes that the spacing between the magnetic sensors is constant, and the spacing X of each magnetic sensor S0 to S3 is as shown in Figure 2. 0 / 1 , X 1 / 2 , X 2 / 3 This method is not applicable if the interval X of each magnetic sensor S0 to S3 changes. 0 / 1 , X 1 / 2 , X 2 / 3 A positioning main switching unit 40 that can appropriately switch between each magnetic sensor S0 to S3 even when the conditions change will be described.

[0036] The positioning primary switching unit 40 in Figure 2 comprises a count value conversion unit 41 and a position calculation unit 42. When the scale body AB of the magnetic scale C spans the detection ranges of two adjacent magnetic sensors S0 / S1, S1 / S2, and S2 / S3, the count value conversion unit 41 switches the positioning primary of the scale body AB from the source magnetic sensors S0, S1, S2 on the opposite side of the direction of movement to the destination magnetic sensors S1, S2, S3 on the side of the direction of movement, by the interval X between each magnetic sensor S0 to S3. 0 / 1 , X 1 / 2 , X 2 / 3 Based on this, the switching count values ​​of the counting units 50, 51, and 52 of the source magnetic sensors S0, S1, and S2 are converted to the starting count values ​​of the counting units 51, 52, and 53 of the destination magnetic sensors S1, S2, and S3. The position calculation unit 42 calculates the interval X between each magnetic sensor S0 to S3. 0 / 1 , X 1 / 2 , X 2 / 3 Based on this, the relative position of the magnetic scale C with respect to the source magnetic sensors S0, S1, and S2 is calculated from the count values ​​of the counting units 51, 52, and 53 of the destination magnetic sensors S1, S2, and S3. Hereinafter, the relative position of the reference mark Z of the magnetic scale C with respect to the 0th magnetic sensor S0, which is used as a reference sensor and calculated by the position calculation unit 42, is also referred to as the absolute position of the reference mark Z of the magnetic scale C or simply the absolute position of the magnetic scale C.

[0037] Figures 4 to 8 show an example of the switching control of each magnetic sensor S0 to S3 by the positioning main switching unit 40. Figure 4 shows the same state as Figure 2, where the counting unit 50 of the 0th magnetic sensor S0, which is the reference sensor that detected the reference mark Z, starts counting the A / B phase magnetic scale of the magnetic scale C from a count value of "0". At this time, the absolute position of the magnetic scale C (relative to the 0th magnetic sensor S0) is equal to the count value of the counting unit 50, "0".

[0038] Figure 5 shows the state in which the center of the magnetic scale C's direction of movement (position of reference mark Z), after moving from the state in Figure 4, is at the midpoint of the 0th magnetic sensor S0 and the 1st magnetic sensor S1. At this time, magnetic sensors S0 and S1 are at the first switching position SW1 and the second switching position SW2, which are symmetrical with respect to the center of the magnetic scale C, and the positioning main body of the magnetic scale C is switched from magnetic sensor S0 to magnetic sensor S1. Note that the switching from magnetic sensor S0 to magnetic sensor S1 only needs to be performed when the scale body AB straddles the detection range of magnetic sensors S0 and S1, and does not necessarily need to be performed at the first switching position SW1 and the second switching position SW2, which are symmetrical with respect to the center of the magnetic scale C (as will be described later, it may be performed at a position shifted within 1 mm to the left or right of the illustrated position). However, as shown below, by making the first switching position SW1 and the second switching position SW2 symmetrical with respect to the center of the magnetic scale C, the calculations in the count value conversion unit 41 and the position calculation unit 42 can be simplified.

[0039] In Figure 5, the first switching position SW1 is located within the scale body AB, 1 mm from the boundary between the left end EL and the scale body AB, and the second switching position SW2 is located within the scale body AB, 1 mm from the boundary between the right end ER and the scale body AB. In this case, the distance from the center of the scale body AB to the first switching position SW1 and the distance from the center of the scale body AB to the second switching position SW2 are 15 mm, and their sum (30 mm) is the distance X between magnetic sensors S0 and S1. 0 / 1 This matches. In this embodiment, where the sensor resolution R is constant at "1,000", the count value of the counting unit 50 of the 0th magnetic sensor S0, which detected 15 mm of A / B phase magnetic scale from the state in Figure 4, is "+15,000", and this becomes the switched count value C0.

[0040] When the count value conversion unit 41 switches the positioning primary of the magnetic scale C from the source 0th magnetic sensor S0 to the destination 1st magnetic sensor S1, the distance X between the 0th magnetic sensor S0 and the 1st magnetic sensor S1 0 / 1 (30mm) Corresponding count value (30,000: Below this, "Interval X 0 / 1Based on the value "30,000", the switching count value C0 "+15,000" of the counting unit 50 of the 0th magnetic sensor S0 is set to the starting count value C1 of the counting unit 51 of the 1st magnetic sensor S1, so C1 = -X 0 / 1 The conversion is performed by / 2 = -C0. Specifically, C1 = -30,000 / 2 = -15,000 becomes the starting count value C1 of the first magnetic sensor S1. Thus, in this embodiment, regardless of the spacing between each magnetic sensor, the starting count value C1 "-15,000" of the destination magnetic sensor S1 is simply the positive and negative inverted version of the switching count value C0 "+15,000" of the source magnetic sensor S0.

[0041] Furthermore, when the movable element C moves to the opposite side (left side) from Figure 5, the switching count value of the 0th magnetic sensor S0 is set to C0, and the starting count value of the (not shown) -1st magnetic sensor S-1 is set to C -1 If so, C -1 =X -1 / 0 / 2 = -C0. Here, X -1 / 0 is the distance between the -1st magnetic sensor S-1 and the 0th magnetic sensor S0. For example, X -1 / 0 If we set it to 28mm, then C -1 =28,000 / 2=14,000, and C0=-C -1 = -14,000.

[0042] When the position calculation unit 42 calculates the absolute position of the magnetic scale C from the count value C1 (-15,000~) of the counting unit 51 of the magnetic sensor S1 at the destination, the interval X 0 / 1 Simply add "30,000". Specifically, the absolute position of magnetic scale C is the absolute position (count value) of magnetic sensor S1 relative to magnetic sensor S0, which is P1(=X 0 / 1 Assuming =30,000), the calculation is performed as P1 + C1, and in the state shown in Figure 5 (C1 = -15,000), the calculation is correctly performed as 30,000 - 15,000 = 15,000. Also, when the movable element C moves to the opposite side (left side) from Figure 5, the absolute position (count value) of magnetic sensor S-1 relative to magnetic sensor S0 is set to P -1 (=-X -1 / 0 Assuming P = -28,000, -1 +C -1 , and the calculation is performed as C-1 When the value is 14,000, the calculation -28,000 + 14,000 = -14,000 is performed correctly.

[0043] Figure 6 shows the state in which the center of the magnetic scale C in the direction of movement (position of reference mark Z) is above the first magnetic sensor S1, after moving from the state in Figure 5. Since the magnetic scale C has moved 15 mm from the state in Figure 5, the count value C1 of the counting unit 51 of the first magnetic sensor S1 is "0", which is obtained by adding "+15,000" for the movement to "-15,000" in Figure 5. Thus, in this embodiment, the count values ​​of the counting units 51 to 53 of magnetic sensors S1 to S3, other than the 0th magnetic sensor S0 which acts as the reference sensor, are always "0" when the center of the magnetic scale C is detected. Furthermore, the position calculation unit 42 correctly calculates the absolute position of the magnetic scale C as 30,000 + 0 = 30,000 using the above formula P1 + C1.

[0044] Figure 7 shows the state in which the center of the magnetic scale C's direction of movement (position of reference mark Z), after moving from the state in Figure 6, is at the midpoint of the first magnetic sensor S1 and the second magnetic sensor S2. At this time, magnetic sensors S1 and S2 are at the first switching position SW1 and the second switching position SW2, which are symmetrical with respect to the center of the magnetic scale C, and the positioning main body of the magnetic scale C is switched from magnetic sensor S1 to magnetic sensor S2. Note that the switching from magnetic sensor S1 to magnetic sensor S2 only needs to be performed when the scale body AB straddles the detection range of magnetic sensors S1 and S2, and does not necessarily need to be performed at the first switching position SW1 and the second switching position SW2, which are symmetrical with respect to the center of the magnetic scale C (as will be described later, it may be performed at a position shifted within 3 mm to the left or right of the illustrated position). However, as shown below, by making the first switching position SW1 and the second switching position SW2 symmetrical with respect to the center of the magnetic scale C, the calculations in the count value conversion unit 41 and the position calculation unit 42 can be simplified.

[0045] In Figure 7, the first switching position SW1 is located within the scale body AB, 3 mm from the boundary between the left end EL and the scale body AB, and the second switching position SW2 is located within the scale body AB, 3 mm from the boundary between the right end ER and the scale body AB. In this case, the distance from the center of the scale body AB to the first switching position SW1 and the distance from the center of the scale body AB to the second switching position SW2 are 13 mm, and their sum (26 mm) is the distance X between magnetic sensors S1 and S2. 1 / 2 This matches. In this embodiment, where the sensor resolution R is constant at "1,000", the count value C1 of the counting unit 51 of the first magnetic sensor S1, which detected 13 mm of A / B phase magnetic scale from the state in Figure 6 (C1=0), is "+13,000", and this becomes the switched count value C1.

[0046] When the count value conversion unit 41 switches the positioning primary of the magnetic scale C from the first magnetic sensor S1 at the source of movement to the second magnetic sensor S2 at the destination, the distance X between the first magnetic sensor S1 and the second magnetic sensor S2 1 / 2 (26mm) Corresponding count value (26,000: Below this, "Interval X 1 / 2 Based on the value "26,000", the switching count value C1 "+13,000" of the counting unit 50 of the first magnetic sensor S1 is set to the starting count value C2 of the counting unit 51 of the second magnetic sensor S2, C2 = -X 1 / 2 The conversion is performed by / 2 = -C1. Specifically, C2 = -26,000 / 2 = -13,000 becomes the starting count value C2 of the second magnetic sensor S2. Thus, in this embodiment, regardless of the spacing between each magnetic sensor, the starting count value C2 "-13,000" of the destination magnetic sensor S2 is simply the positive and negative inverted version of the switching count value C1 "+13,000" of the source magnetic sensor S1. Note that X 0 / 1 (30mm) and X 1 / 2 In this embodiment, where the (26mm) values ​​differ from one another, the starting count value "-15,000" in Figure 5 and the switching count value "+13,000" in Figure 7 of the first magnetic sensor S1 are not simply polarity inversions.

[0047] When the position calculation unit 42 calculates the absolute position of the magnetic scale C from the count value C2 (-13,000~) of the counting unit 52 of the magnetic sensor S2 at the destination, it uses an interval X representing the distance of the magnetic sensor S2 from the 0th magnetic sensor S0, which serves as the reference sensor. 0 / 1 "30,000" and interval X 1 / 2 Simply add the sum of "26,000". Specifically, the absolute position of magnetic scale C is the absolute position (count value) of magnetic sensor S2 relative to magnetic sensor S0, which is P2 (=X 0 / 1 +X 1 / 2 Assuming = 56,000), the calculation P2 + C2 is performed, and in the state shown in Figure 7 (C2 = -13,000), the calculation is correctly performed as 56,000 - 13,000 = 43,000.

[0048] Figure 8 shows the state in which the center of the magnetic scale C in the direction of movement (position of reference mark Z) is above the second magnetic sensor S2, after moving from the state in Figure 7. Since the magnetic scale C has moved 13 mm from the state in Figure 7, the count value C2 of the counting unit 52 of the second magnetic sensor S2 is "0", which is obtained by adding "+13,000" for the movement to "-13,000" in Figure 7. Thus, in this embodiment, the count values ​​of the counting units 51 to 53 of the magnetic sensors S1 to S3, other than the 0th magnetic sensor S0 which acts as the reference sensor, are always "0" when the center of the magnetic scale C is detected. Furthermore, the position calculation unit 42 correctly calculates the absolute position of the magnetic scale C as 56,000 + 0 = 56,000 using the above formula P2 + C2.

[0049] According to the above embodiment, regardless of the spacing between each magnetic sensor, the starting count value of the destination magnetic sensor is simply the positive and negative inverted version of the switching count value of the source magnetic sensor. Furthermore, in this embodiment, even for magnetic sensors other than the reference sensor, the count value of the counting unit is always "0" when detecting the center of the magnetic scale C. Moreover, in this embodiment, when the position calculation unit 42 calculates the absolute position of the magnetic scale C, it is sufficient to simply add the count value representing the distance between the magnetic sensor and the reference sensor to the count value of the positioning-main magnetic sensor's counting unit.

[0050] Next, the multiple circuit boards included in the positioning device 4 according to this embodiment will be described. Figure 9 schematically shows the multiple circuit boards B1 to B3 included in the positioning device 4. In Figure 9, three circuit boards B1 to B3 are shown as the multiple circuit boards included in the positioning device 4, but there may be two circuit boards or four or more. Hereinafter, three circuit boards B1 to B3 will be used as examples for explanation.

[0051] Multiple substrates B1 to B3 are embedded in or positioned in the rail surface 21 along the trajectory direction of the stator 2 or the direction of movement of the movable element C (left-right direction in Figure 9). Substrates B1 and B2 are positioned adjacent to each other along the direction of movement. Substrates B2 and B3 are positioned adjacent to each other along the direction of movement. Magnetic sensors S1 to S16 are positioned on substrate B1. Magnetic sensors T1 to T16 are positioned on substrate B2. Magnetic sensors U1 to U16 are positioned on substrate B3. Figure 9 shows an example where each substrate has 16 magnetic sensors, but each substrate only needs to have one or more magnetic sensors.

[0052] Each magnetic sensor S1-S16, T1-T16, and U1-U16 is configured in the same way as each magnetic sensor S0-S3 in Figure 2. The spacing between each magnetic sensor S1-S16, T1-T16, and U1-U16 in the direction of movement may be different from each other, but in this embodiment, an example in which all spacings are equal will be described. In this case, the spacing between each magnetic sensor S1-S16, T1-T16, and U1-U16 in the direction of movement is, for example, 30 mm. The above description applies not only to the spacing between each magnetic sensor in the direction of movement arranged on a single substrate, but also to the spacing between two adjacent magnetic sensors that span two adjacent substrates, for example, the spacing between magnetic sensor S16 on substrate B1 and magnetic sensor T1 on substrate B2, or the spacing between magnetic sensor T16 on substrate B2 and magnetic sensor U1 on substrate B3. Thus, in this embodiment, the distance between each magnetic sensor S1-S16, T1-T16, and U1-U16 in the direction of movement (30 mm) is smaller than the length of the magnetic scale C in the direction of movement (48 mm). Specifically, the distance between the magnetic sensor S16 on substrate B1 and the magnetic sensor T1 on substrate B2 along the direction of movement is smaller than the length of the magnetic scale C in the direction of movement. Also, the distance between the magnetic sensor T16 on substrate B2 and the magnetic sensor U1 on substrate B3 along the direction of movement is smaller than the length of the magnetic scale C in the direction of movement.

[0053] Each magnetic sensor S1-S16, T1-T16, and U1-U16, similar to each magnetic sensor S0-S3 in Figure 2, is equipped with a counting unit (not shown) that counts the A / B phase magnetic scales formed on the scale body AB and / or both ends EL and ER of the magnetic scale C. Each substrate B1-B3 is equipped with a positioning main switching unit 40 as shown in Figure 2. Each substrate B1-B3 has an individual logic circuit, and this individual logic circuit functions as the positioning main switching unit 40. The logic circuit is, for example, an FPGA.

[0054] Two adjacent circuit boards are connected to each other in a way that allows them to communicate with one another. This communication does not depend on the clock source of the logic circuit, and for example, an asynchronous communication method can be used. The detection signals (A-phase, B-phase, and Z-phase pulses) of two adjacent magnetic sensors spanning the two adjacent circuit boards are shared between the two boards through communication. Specifically, the detection signal of magnetic sensor S16 on board B1 is transmitted to board B2. Similarly, the detection signal of magnetic sensor T1 on board B2 is transmitted to board B1. The same applies between board B2 and board B3.

[0055] The positioning primary switching unit 40 of each board B1 to B3 uses detection signals from adjacent boards B1 to B3 to control the switching of two adjacent magnetic sensors that span two adjacent boards. When the magnetic scale C spans the detection range of the magnetic sensors (e.g., magnetic sensors S16 and T1) of two adjacent boards (e.g., boards B1 and B2), and the positioning primary of the magnetic scale C switches from the source magnetic sensor S16 on the opposite side of the direction of movement to the destination magnetic sensor T1 on the direction of movement, the positioning primary switching unit 40 of the source board B1 treats the magnetic sensor that will be the primary positioning sensor as no longer being the source magnetic sensor S16, meaning that the magnetic scale C is not a target for positioning on the source board B1. At this time, the positioning primary switching unit 40 of the destination board B2 switches from a state where there is no magnetic sensor that will be the primary positioning sensor to a state where the destination magnetic sensor T1 is the primary positioning sensor. The position calculation unit 42 of the positioning main switching unit 40 of the destination board B2 calculates the absolute position of the magnetic scale C in the entire linear transport system 1 by adding the absolute position of the magnetic scale C in board B2, which is calculated on the destination board B2, to the absolute position of the magnetic scale C in board B1, which is calculated on board B1, which is calculated on board B1.

[0056] Each board B1 to B3 transmits information about the absolute position of the magnetic scale C, calculated by the positioning main switching unit 40 of each board B1 to B3, to the controller 70 using the individual logic circuits described above. The controller 70 uses the information about the absolute position of the magnetic scale C received from each board B1 to B3 to drive and control the movable element 3. The controller 70 includes a position determination unit 72, the details of which will be described later.

[0057] Figure 10 schematically shows how the magnetic sensor S16 on the source board B1 detects the reference mark Z of the magnetic scale C. Figure 11 schematically shows how the positioning location of the magnetic scale C switches from the magnetic sensor S16 on the source board B1 to the magnetic sensor T1 on the destination board B2. Figure 12 is a timing chart schematically showing an example of the time changes of the sensors used (the magnetic sensors that are the main point of positioning) on ​​each board B1 and B2, the count values ​​of the magnetic sensors, and the absolute position of the movable element.

[0058] As shown in Figures 10 and 12, when the magnetic scale C moves from the left to the right in Figure 10 and the magnetic sensor S16 detects the reference mark Z as the reference mark of the magnetic scale C, the magnetic sensor S16 outputs a Z-phase pulse. At this time, the counting unit of the magnetic sensor S16 starts counting the A / B phase magnetic scale of the magnetic scale C from a count value of "0". At this point, as shown in Figure 12, the sensor used on substrate B1 is the magnetic sensor S16, and there are no sensors used on substrate B2. In the example shown in Figure 12, during the period when there are no sensors used on substrate B2, the position calculation unit 42 of substrate B2 sets the absolute position of the magnetic scale C within substrate B2 and the absolute position of the magnetic scale C in the entire linear transport system 1 as invalid values ​​of "0x7FFFFFFF". Similarly, during the period when there are no sensors used on substrate B2, the positioning main switching unit 40 of substrate B2 sets the sensors used on substrate B2 as invalid values ​​of "0x7FFFF".

[0059] As shown in Figure 11, when the center of the magnetic scale C's movement direction (position of reference mark Z), which has moved from the state shown in Figure 10, reaches the midpoint between magnetic sensor S16 and magnetic sensor T1, the positioning main of magnetic scale C is switched from magnetic sensor S16 to magnetic sensor T1. At this time, the switching count value "15,000" of the counting unit of magnetic sensor S16 is converted to the starting count value "-15,000" of the counting unit of magnetic sensor T1. From this point onward, magnetic sensor T1 becomes the positioning main of magnetic scale C, and its counting unit counts from the starting count value "-15,000" to the switching count value "+15,000" for the next magnetic sensor T2. After the positioning main of magnetic scale C is switched to magnetic sensor T1, as shown in Figure 12, there are no sensors used on board B1, and the sensor used on board B2 is magnetic sensor T1. In the example shown in Figure 12, during periods when no sensors are in use on substrate B1, the position calculation unit 42 of substrate B1 sets the absolute position of magnetic scale C within substrate B1 and the absolute position of magnetic scale C in the entire linear transport system 1 as invalid values, set to "0x7FFFFFFF". Similarly, during periods when no sensors are in use on substrate B1, the positioning main switching unit 40 of substrate B1 sets the sensors in use on substrate B1 as invalid values, set to "0x7FFFF".

[0060] Thus, even when the magnetic scale C moves between two adjacent substrates, the destination magnetic sensor takes over the count value from the source magnetic sensor and performs counting. In addition, the position calculation unit 42 of the substrate having the positioning-focused magnetic sensor calculates the absolute position of the magnetic scale C within the entire linear transport system 1.

[0061] As mentioned above, each board B1 to B3 uses its own logic circuit, such as an FPGA, to operate the positioning primary switching unit 40 and transmit the absolute position of the magnetic scale C to the controller 70. Since these individual logic circuits operate on their own clock sources, the timing of the processing using the logic circuits on each board B1 to B3 is not strictly synchronized.

[0062] Figure 13 is a timing chart showing an enlarged portion of Figure 12. As shown in Figure 13, the clock timing of the logic circuit on board B1 and the clock timing of the logic circuit on board B2 are not perfectly synchronized. In the example shown in Figure 13, the sampling rate of the clock source for each logic circuit is 100 MHz, and the timing is off by approximately 2 nanoseconds. Therefore, around the timing shown in Figure 11, it is possible for a momentary state to occur where the positioning main body of the magnetic scale C is such that the magnetic sensor S16 on board B1 is no longer in use, and the magnetic sensor T1 on board B2 is not yet in use. This period is shown as period G in Figure 13. Consequently, if the controller 70 acquires absolute position information of the magnetic scale C from boards B1 and B2 during period G, the controller 70 may misdetect the position of the magnetic scale C. In the example shown in Figure 13, during period G, the absolute position of the magnetic scale C received from substrates B1 and B2 is "0x7FFFFFFF", causing a gap in the measurement value, and the controller 70 cannot correctly measure the position of the magnetic scale C.

[0063] Therefore, this embodiment aims to improve the reliability of position detection of a movable element moving between two adjacent substrates. Figure 14 is a timing chart schematically showing the time changes of the sensors used, count values, and absolute position of the movable element for each substrate in this embodiment. The embodiment shown in Figure 14 differs from the example shown in Figure 12 in that substrate B1 uses a virtual sensor S17.

[0064] In this embodiment, when the magnetic scale C spans the detection ranges of the magnetic sensors S16 and T1 on the two substrates B1 and B2, respectively (as shown in Figure 11), when switching the positioning primary of the magnetic scale C from the source magnetic sensor S16 to the destination magnetic sensor T1, the destination substrate B2 outputs at least one count value, including the first count value counted by the destination magnetic sensor T1 after the switch, to the source substrate B1. The source substrate B1 uses the count value input from the destination substrate B2 to perform counting using the virtual sensor S17, which acts as a virtual position detection unit. In the example shown in Figure 14, substrate B2 transmits the count values ​​of magnetic sensor T1, such as "-15,000", "-14,999", etc., to substrate B1 as needed. As described above, communication between the two adjacent substrates B1 and B2 does not depend on the clock source of the logic circuit. The board B2 may transmit the count value of magnetic sensor T1 to board B1 until the positioning primary of magnetic scale C is switched from magnetic sensor T1 to magnetic sensor T2.

[0065] The positioning primary switching unit 40 of board B1 switches the positioning primary from magnetic sensor S16 to virtual sensor S17, similar to switching the positioning primary between actual magnetic sensors within board B1. The counting unit of virtual sensor S17 of board B1 performs counting in parallel with the counting unit of magnetic sensor T1, using the count value received from magnetic sensor T1. The position calculation unit 42 of board B1 calculates the absolute position of magnetic scale C using the count value of virtual sensor S17. Note that the counting unit of virtual sensor S17 is a virtual counting unit and can be implemented, for example, as a function of the positioning primary switching unit 40 of board B1.

[0066] The position determination unit 72 of the controller 70 determines the position of the magnetic scale C based on either the count value obtained by the virtual sensor S17, which acts as a virtual position detection unit on the source substrate B1, or the count value obtained by the magnetic sensor T1, which acts as a position detection unit on the destination substrate B2. In this embodiment, either the absolute position of the magnetic scale C calculated on substrate B1 or the absolute position of the magnetic scale C calculated on substrate B2 is determined as the absolute position of the magnetic scale C.

[0067] Figure 15 is a timing chart showing an enlarged portion of Figure 14. As shown in Figure 15, during the period G described in Figure 13, the absolute position of the magnetic scale C calculated on the substrate B1 is correctly calculated as "480,000" based on the virtual sensor S17. Therefore, the controller 70 can perform stable measurements without measurement jumps by using the absolute position of the magnetic scale C calculated on the substrate B1 during period G.

[0068] In this way, when the magnetic scale C moves between two adjacent substrates, even after the measurement by the magnetic sensor on the source substrate has finished, the measurement can be virtually continued on the source substrate using the measurement value from the magnetic sensor on the destination substrate. Therefore, even if there is a difference in processing timing on each substrate, the position of the magnetic scale C can be reliably maintained. This improves the reliability of position detection of the movable element moving between two adjacent substrates.

[0069] In the example shown in Figure 15, the count value of magnetic sensor S16 is updated even after the positioning main body of magnetic scale C is switched from magnetic sensor S16 to magnetic sensor T1. This is because, as shown in Figure 3, the positioning main body is switched at a predetermined distance (e.g., 1 mm) from the boundary between the left end EL of magnetic scale C and the scale body AB within the scale body AB, so even after the positioning main body of magnetic scale C is switched from magnetic sensor S16 to magnetic sensor T1, the counting unit of magnetic sensor S16 can still count for the predetermined distance. However, if the predetermined distance is shorter, or if the movement speed of the movable element 3 is faster than a certain amount, it is difficult for the controller 70 to acquire the count value of magnetic sensor S16 after the positioning main body has been switched to magnetic sensor T1. Therefore, as described above, it is effective to virtually continue measurement on the source board using the measurement value of the magnetic sensor on the destination board.

[0070] In the above embodiment, the case where the magnetic scale C moves to the right in Figure 10, etc., has been described, but the magnetic scale C may also move to the left in Figure 10, etc. In this case, in the description of this embodiment, the source board is board B2, the destination board is board B1, the source magnetic sensor is magnetic sensor T1, and the destination magnetic sensor is magnetic sensor S16. When switching the positioning main of the magnetic scale C from the source magnetic sensor T1 to the destination magnetic sensor S16, the destination magnetic sensor S16 outputs at least one count value, including the first count value counted after the switch, from the destination board B1 to the source board B2. The source board B2 uses the count value input from the destination board B1 to perform counting by the virtual sensor T0, which acts as a virtual position detection unit.

[0071] The positioning primary switching unit 40 of board B2 switches the positioning primary from magnetic sensor T1 to virtual sensor T0, similar to the switching of the positioning primary between actual magnetic sensors within board B2. The counting unit of virtual sensor T0 of board B2 then performs counting in parallel with the counting unit of magnetic sensor S16 using the count value received from magnetic sensor S16. The position calculation unit 42 of board B2 calculates the absolute position of magnetic scale C using the count value of virtual sensor T0.

[0072] The present disclosure has been described above based on embodiments. Various modifications are possible for each component and each combination of processes in the exemplary embodiments, and it will be obvious to those skilled in the art that such modifications are included in the scope of the present disclosure.

[0073] In the embodiments, a linear transport system is illustrated in which a movable element is driven based on the magnetic force between a permanent magnet provided on the movable element and an electromagnet provided on the stator. However, this disclosure can be applied to any drive device based on any principle other than magnetism (e.g., electricity or fluid).

[0074] The configuration, operation, and function of each device and method described in the embodiments can be realized by hardware resources or software resources, or by the cooperation of hardware resources and software resources. Hardware resources include, for example, processors, ROMs, RAMs, and various integrated circuits. Software resources include, for example, operating systems and application programs. [Explanation of symbols]

[0075] 1 Linear transport system, 2 Stator, 3 Movable, 4 Positioning device, 40 Positioning main switching unit, B Circuit board, C Movable, 70 Controller, 72 Position determination unit.

Claims

1. It comprises two substrates arranged adjacent to each other along the direction of movement of the movable element, Each of the two substrates has a position detection unit for positioning a positioning scale to be attached to the movable element. When the positioning scale spans the detection range of the position detection units of each of the two boards, and the positioning entity of the positioning scale is switched from the position detection unit of the source of movement on the opposite side of the direction of movement to the position detection unit of the destination on the direction of movement side, at least one count value, including the first count value counted after the switch at the destination position detection unit, is output from the destination board to the source board. Positioning device.

2. The source board performs counting using a virtual position detection unit with respect to at least one count value input from the destination board. The positioning device according to claim 1.

3. The system further includes a position determination unit that determines the position of the positioning scale based on either the count value obtained by the virtual position detection unit on the source board or the count value obtained by the position detection unit on the destination board. The positioning device according to claim 2.

4. The positioning scale is a magnetic scale provided with multiple magnetic scales, Each of the two substrates has a position detection unit which is a magnetic sensor equipped with a magnetic detection head for detecting the magnetic scale. The positioning device according to claim 1.

5. The distance between the position detection units of each of the two substrates along the direction of movement is smaller than the length of the positioning scale in the direction of movement. A positioning device according to any one of claims 1 to 4.

6. A movable element driven along a track, The system comprises two substrates arranged adjacent to each other along the aforementioned track, Each of the two substrates has a position detection unit for positioning a positioning scale to be attached to the movable element. When the positioning scale spans the detection range of the position detection units of each of the two substrates, and the positioning entity of the positioning scale is switched from the source position detection unit on the opposite side of the movable element's movement direction to the destination position detection unit on the movement direction side, at least one count value, including the first count value counted after the switch at the destination position detection unit, is output from the destination substrate to the source substrate. Drive unit.

7. A positioning device comprising two substrates arranged adjacent to each other along the direction of movement of a movable element, wherein each of the two substrates has a position detection unit for positioning a positioning scale attached to the movable element, A positioning method in which, when the positioning scale spans the detection range of the position detection units of each of the two boards, the positioning entity of the positioning scale is switched from the source position detection unit on the opposite side of the direction of movement to the destination position detection unit on the direction of movement side, the method includes the step of outputting at least one count value, including the first count value counted after the switch by the destination position detection unit, from the destination board to the source board.

8. A positioning device comprising two substrates arranged adjacent to each other along the direction of movement of a movable element, wherein each of the two substrates has a position detection unit for positioning a positioning scale attached to the movable element, A positioning program that, when the positioning scale spans the detection range of the position detection units of each of the two boards, causes a computer to perform the step of outputting at least one count value, including the first count value counted after the switch at the destination position detection unit, from the destination board to the source board, when switching the positioning entity of the positioning scale from the source position detection unit on the opposite side of the direction of movement to the destination position detection unit on the direction of movement side.

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