Conveying device and control method for a conveying device

Abstract

This invention provides a conveying device and control method that can more accurately maintain the posture of a moving body. The conveying device includes: a moving body; a top plate disposed above the moving body at a distance; a magnetic plate including a plurality of permanent magnets, the plurality of permanent magnets being arranged parallel to a predetermined direction of movement on the lower surface of the top plate with adjacent permanent magnets having different polarities; a travel control coil unit including a plurality of excitation coils, the plurality of excitation coils being disposed at a distance from the predetermined magnetic plate on the upper surface of the moving body along the predetermined magnetic plate; an upper spacing control coil unit including a plurality of excitation coils, the plurality of excitation coils being disposed at a distance from the predetermined magnetic plate on the upper surface of the moving body along the same or different magnetic plate; and a control device that supplies drive current to the travel control coil unit and the upper spacing control coil unit respectively, causing the moving body to move along the direction of movement, and controlling the upper spacing.

Description

TECHNICAL FIELD

[0001] The present application relates to a conveyance device and a control method of a conveyance device. The present application particularly relates to a linear motor-driven suspension conveyance device and a control method thereof. BACKGROUND

[0002] There is a linear motor-driven suspension conveyance device. The linear motor-driven suspension conveyance device, for example, is provided with a rail on the top, and loads an article such as a container in a bucket suspended from a mobile body. The linear motor causes the mobile body to travel along the rail. In the linear motor-driven suspension conveyance device, generally, a magnetic plate is arranged on the rail, and a traveling control coil unit including a plurality of excitation coils is arranged on the upper surface of the mobile body of the trolley. The magnetic plate and the traveling control coil unit are arranged facing each other at a prescribed interval (hereinafter referred to as an upper interval). If a drive current is supplied to the excitation coils, a magnetic field is generated at the upper interval, and the mobile body moves in a prescribed direction along the magnetic plate.

[0003] In such a conveyance device, it is desirable to provide a posture maintaining member that maintains the upper interval between the magnetic plate and the traveling control coil unit and maintains the posture of the mobile body. For example, in Japanese Patent Publication No. 2018-069838, as a posture maintaining member, a conveyance device including rollers (gap rollers) in front and rear of the mobile body is disclosed. The rollers, as the mobile body moves, abut against the magnetic plate (magnetic rail) and rotate, maintaining the upper interval to be fixed. SUMMARY

[0004] [PROBLEMS TO BE SOLVED BY THE INVENTION]

[0005] The posture maintaining member such as the rollers does not directly exert an attractive force on the magnetic plate, so there is a possibility that the mobile body tilts due to inertia at the time of starting or stopping conveyance of the mobile body, and the upper interval becomes large or comes into contact with other members.

[0006] Further, the linear motor-driven conveyance device can convey the mobile body in a non-contact form, so it is also provided in a space such as a clean room where high cleanliness is required. However, in the case where the contact-type posture maintaining member such as the rollers is provided, there is a possibility that dust is generated at the abutting position with the posture maintaining member.

[0007] The present application was completed in view of such a situation, and aims to provide a conveyance device that can more accurately maintain the posture of the mobile body by maintaining the upper interval with a non-contact member.

[0008] [MEANS FOR SOLVING THE PROBLEMS]

[0009] According to the present application, there is provided a conveyance device including: a moving body; a top plate provided above the moving body with a space from the moving body; at least one magnetic plate including a plurality of permanent magnets arranged on a lower surface of the top plate in parallel with a prescribed moving direction with different polarities of adjacent ones; a travel control coil unit including a plurality of field coils provided on an upper surface of the moving body with a space from a prescribed magnetic plate among the at least one magnetic plate along the prescribed magnetic plate; at least two upper gap control coil units including a plurality of field coils provided on the upper surface of the moving body with a space from the same or different magnetic plate among the at least one magnetic plate from the prescribed magnetic plate; and a control device that supplies drive currents to the travel control coil unit and the at least two upper gap control coil units respectively, moves the moving body along the moving direction, and controls a gap, i.e., an upper gap, between the magnetic plate and the at least two upper gap control coil units.

[0010] Further, according to the present application, there is provided a control method of a conveyance device including: a moving body; a top plate provided above the moving body with a space from the moving body; at least one magnetic plate including a plurality of permanent magnets arranged on a lower surface of the top plate in parallel with a prescribed moving direction with different polarities of adjacent ones; a travel control coil unit including a plurality of field coils provided on an upper surface of the moving body with a space from a prescribed magnetic plate among the at least one magnetic plate along the prescribed magnetic plate; and at least two upper gap control coil units including a plurality of field coils provided on the upper surface of the moving body with a space from the same or different magnetic plate among the at least one magnetic plate from the prescribed magnetic plate, the control method of the conveyance device supplying drive currents to the travel control coil unit and the at least two upper gap control coil units respectively, moving the moving body along the moving direction, and controlling a gap, i.e., an upper gap, between the magnetic plate and the at least two upper gap control coil units.

[0011] [Effects of the Invention]

[0012] In addition to the travel control coil unit, the conveying device of the present invention also includes an upper spacing control coil unit comprising a plurality of excitation coils. By supplying a drive current to the upper spacing control coil unit, an attractive or repulsive force is generated between the magnetic plate and the upper spacing control coil unit, thereby controlling the distance between the magnetic plate and the upper spacing control coil unit, i.e., the upper spacing, and thus controlling the distance between the magnetic plate and the travel control coil unit to a predetermined size. This allows for more accurate maintenance of the posture of the moving body. Furthermore, since the magnetic plate and the upper spacing control coil unit are kept in a non-contact state, dust generation is suppressed. Attached Figure Description

[0013] Figure 1 This is a side view of the conveying device in this embodiment.

[0014] Figure 2 yes Figure 1 AA arrow view sectional view.

[0015] Figure 3 This is a cross-sectional view of the conveying device in a variation example.

[0016] Figure 4 This is a block diagram of the control device in this embodiment.

[0017] Figure 5 This is a block diagram of the travel control device in this embodiment.

[0018] Figure 6 This is a block diagram of the upper spacing control device in this embodiment.

[0019] Figure 7 This is a block diagram of the lateral spacing control device of this embodiment.

[0020] [Explanation of Symbols]

[0021] 1: Transport device

[0022] 2: Moving body

[0023] 3: Track

[0024] 4: Travel control coil unit

[0025] 5: Upper spacing control coil unit

[0026] 6: Lateral spacing control coil unit

[0027] 7: Roller

[0028] 8: Control device

[0029] 31: Top plate

[0030] 33: Side panel

[0031] 35: magnetic plate

[0032] 35n, 35s: permanent magnet

[0033] 41, 51, 61: field coil

[0034] 41u, 51u: u-phase coil

[0035] 41v, 51v: v-phase coil

[0036] 43: position / magnetic pole sensor

[0037] 53: upper clearance sensor

[0038] 63: lateral clearance sensor

[0039] 80: host device

[0040] 81: travel control device

[0041] 83: upper clearance control device

[0042] 85: lateral clearance control device

[0043] 431: position sensor

[0044] 433: magnetic pole sensor

[0045] 811: travel control section

[0046] 812, 832: phase calculator

[0047] 813a, 813b, 833a, 833b, 853: PI control section

[0048] 814, 834: reverse d-q conversion section

[0049] 815, 835, 855: power amplifier

[0050] 816, 836, 856: A / D converter

[0051] 817, 837: d-q conversion section

[0052] 831: upper clearance control section

[0053] 851: lateral clearance control section DETAILED DESCRIPTION

[0054] Hereinafter, embodiments of the present application will be described using the drawings. The various modifications described below can be implemented in combination, as appropriate. In addition, the direction in which the mobile body 2 moves, i.e., the direction of the arrow in the drawings, will be referred to as the front direction, the direction opposite to the front direction will be referred to as the rear direction, the left side in the drawings will be referred to as the left side, and the right side in the drawings will be referred to as the right side. Figure 1The left-right direction in the above-described embodiment is referred to as a moving direction, and a horizontal direction orthogonal to the moving direction, i.e. Figure 2 and Figure 3 The left-right direction in the above-described embodiment is referred to as a width direction.

[0055] Figure 1 and Figure 2 A conveyance device 1 of the present embodiment shown in FIG. 1 is a so-called linear motor driven suspension type conveyance device that conveys a moving body 2 by a magnetic force generated above the moving body 2. The conveyance device 1 of the present embodiment includes the moving body 2, a rail 3, a magnetic plate 35, a traveling control coil unit 4, a position / magnetic pole sensor 43, an upper gap control coil unit 5, an upper gap sensor 53, a side gap control coil unit 6, a side gap sensor 63, and a control device.

[0056] For example, a bucket is suspended from the moving body 2, and an article to be conveyed is mounted on the bucket. The traveling control coil unit 4, the upper gap control coil unit 5, the position / magnetic pole sensor 43, and the upper gap sensor 53 are respectively mounted on the upper surface of the moving body 2. Further, the side gap control coil unit 6 and the side gap sensor 63 are respectively mounted on the side surface of the moving body 2.

[0057] The rail 3 is a member such as a cross-sectional H-shaped member that is fixed to a predetermined position in a manner of covering the moving body 2 from above. Specifically, the rail 3 includes a top plate 31 that is provided above the moving body 2 so as to be spaced apart from the moving body 2, and a pair of side plates 33 that are provided on the side of the moving body 2 so as to be spaced apart from the moving body 2. In the present embodiment, the pair of side plates 33 are respectively erected downward from both ends in the width direction of the top plate 31, but the top plate 31 and the side plates 33 can be respectively provided separately.

[0058] At least one magnetic plate 35 is provided on the lower surface of the top plate 31. The magnetic plate 35 includes a plurality of permanent magnets 35n of N-pole on a surface facing the moving body 2, and a plurality of permanent magnets 35s of S-pole on a surface facing the moving body 2, and the permanent magnets 35n and the permanent magnets 35s are alternately arranged on the top plate 31 so that the adjacent poles are different. Further, the permanent magnets 35n and the permanent magnets 35s are arranged in parallel with the moving direction. In the present embodiment, one magnetic plate 35 is provided on the top plate 31, and the traveling control coil unit 4 and the upper gap control coil unit 5 share the one magnetic plate 35 as described below. By this, the structure of the conveyance device 1 can be made more compact, and thus is preferable. However, the magnetic plate 35 can be respectively provided for the traveling control coil unit 4 and the upper gap control coil unit 5. The traveling control coil unit 4 and the upper gap control coil unit 5 are primary sides, and the magnetic plate 35 is a secondary side, and thus a linear motor is configured.

[0059] The traveling control coil unit 4 is, for example, a coil unit for a three-phase core linear motor including a plurality of field coils 41. The field coils 41 are provided on the upper surface of the moving body 2 so as to be spaced apart from the magnetic plate 35 along the magnetic plate 35. When the field coils 41 are excited, each of the field coils 41 is lifted by the attractive force and the repulsive force generated between the field coil 41 and the permanent magnets 35n and 35s adjacent to the field coil 41, and is carried in the direction in which the permanent magnets 35n and 35s are arranged, that is, the moving direction. The field coils 41 can also be excited by three-phase alternating current of three phases, u phase, v phase, and w phase, which are offset by 120° from each other. At this time, the u-phase coil 41u, the v-phase coil 41v, and the w-phase coil 41w, which are excited by u-phase current, v-phase current, and w-phase current, respectively, are set as one group, and each of the field coils 41 includes a predetermined number of groups.

[0060] The position / pole sensor 43 functions as both a position sensor 431 that detects the position of the moving direction of the moving body 2 and a pole sensor 433 that detects the magnetic field of the permanent magnets 35n and 35s, and is, for example, a magnetic scale. However, the position sensor 431 and the pole sensor 433 can be separately provided, and, for example, an optical sensor can be provided as the position sensor 431 and a Hall element can be provided as the pole sensor 433. As the position sensor 431 and the pole sensor 433, any sensor can be used, and a non-contact sensor is preferable. In the present embodiment, the position / pole sensor 43 is attached to the traveling control coil unit 4, but can be directly or indirectly attached to the moving body 2 via another member. In the present embodiment, when the position and the speed of the moving body 2 are measured, incremental position measurement is performed using the position sensor 431 and the pole sensor 433, but the present embodiment is not limited thereto. For example, as the position / pole sensor 43, any linear position detector such as an optical sensor, an electrostatic capacitance sensor, a laser interference sensor, or a magnetic sensor can be used. Furthermore, absolute position measurement can be performed, in which case the pole sensor 433 can be omitted.

[0061] Each of the upper gap control coil units 5 is, for example, a coil unit for a three-phase core linear motor including a plurality of field coils 51. The field coils 51 are provided on the upper surface of the moving body 2 so as to face the magnetic plates 35 along the magnetic plates 35. As described above, it is preferable that the magnetic plate 35 facing the field coils 41 and the magnetic plate 35 facing the field coils 51 are the same. That is, the field coils 41 and the field coils 51 share the magnetic plate 35. However, a plurality of magnetic plates 35 can be provided, and the magnetic plates 35 facing the field coils 41 and the field coils 51 can be different from each other. The gap between the magnetic plate 35 and the upper gap control coil unit 5, that is, the upper gap is controlled by the attractive force or the repulsive force generated between each of the field coils 51 and the permanent magnet 35n or the permanent magnet 35s facing the field coil 51 after the field coil 51 is excited. The field coils 51 can be excited by three-phase alternating current. At this time, u-phase coils 51u, v-phase coils 51v, and w-phase coils 51w excited by u-phase current, v-phase current, and w-phase current, respectively, are set as one group, and each of the field coils 51 includes a predetermined number of groups. It is desirable that one upper gap control coil unit 5 is provided in front of and behind the travel control coil unit 4 in the moving direction.

[0062] Each of the upper gap sensors 53 detects the size of the upper gap, and is, for example, an infrared sensor. As the upper gap sensor 53, any sensor can be used, and a non-contact sensor is preferable. It is desirable that one upper gap sensor 53 is provided in front of and behind the travel control coil unit 4 in the moving direction. In the present embodiment, each of the upper gap sensors 53 is attached to each of the upper gap control coil units 5, and can be directly attached to or indirectly attached to the moving body 2 through other members.

[0063] When the travel control coil unit 4 and the upper gap control coil unit 5 share one magnetic plate 35, the travel control coil unit 4 and the upper gap control coil unit 5 are provided on the same line along the one magnetic plate 35. Further, when the field coils 41 of the travel control coil unit 4 are excited, a q-axis current is supplied to the travel control coil unit 4 as a drive current. The q-axis current is converted into u-phase current, v-phase current, and w-phase current, and is supplied to the u-phase coils 41u, the v-phase coils 41v, and the w-phase coils 41w, respectively. When the field coils 51 of the upper gap control coil unit 5 are excited, a d-axis current is supplied to the upper gap control coil unit 5 as a drive current. The d-axis current is converted into u-phase current, v-phase current, and w-phase current, and is supplied to the u-phase coils 51u, the v-phase coils 51v, and the w-phase coils 51w, respectively. The d-axis current is a current generating a magnetic field in a direction parallel to the direction of the magnetic field generated by the magnetic plate 35, that is, the N-pole direction. Further, the q-axis current is a current orthogonal to the d-axis current. In other words, the phase of the d-axis current is shifted by 90° from the phase of the q-axis current.

[0064] According to the conveyance device 1 as above, by controlling the size of the upper gap, the posture of the moving body 2 can be maintained. At this time, the magnetic plate 35 and the upper gap control coil unit 5 are maintained in a non-contact state, so that dusting caused by contact is suppressed. In particular, in the present embodiment, the travel control coil unit 4 and the upper gap control coil unit 5 share one magnetic plate 35 to control the movement of the moving body 2 and the upper gap, so that the size of the entire conveyance device 1 can be more compactly configured.

[0065] When conveying the moving body 2, it is desirable that the position of the moving body 2 in the width direction is also restricted. In other words, it is desirable that the lateral gap between the side gap control coil unit 6 and the side plate 33, i.e., the lateral gap, is maintained constant. In the present embodiment, the lateral gap is controlled by the side gap control coil unit 6 and the lateral gap sensor 63.

[0066] Each side gap control coil unit 6 is, for example, a single-phase AC electromagnet or a DC electromagnet including one or more field coils 61. The field coils 61 are provided on the side surface of the moving body 2 so as to be spaced apart from the side plate 33. At this time, at least the facing surface of the side plate 33 with the field coils 61 is a ferromagnetic body. After the field coils 61 are excited, the lateral gap is controlled by the attractive force generated between each field coil 61 and the side plate 33. When the side gap control coil unit 6 is a single-phase AC electromagnet, the side gap control coil unit 6 is excited by single-phase AC. When the side gap control coil unit 6 is a DC electromagnet, the side gap control coil unit 6 is excited by DC. As the side gap control coil unit 6 of the single-phase AC electromagnet or the DC electromagnet, one is provided on each of the two side surfaces of the moving body 2.

[0067] In addition, the side gap control coil unit 6 can also be a three-phase core linear motor coil unit including a plurality of field coils. The field coils can be excited by three-phase AC. At this time, the u-phase coil, the v-phase coil, and the w-phase coil excited by the u-phase current, the v-phase current, and the w-phase current, respectively, are set as one group, and the field coils include a predetermined number of groups. As the side gap control coil unit 6 of the three-phase core linear motor, one can be provided on each of the two side surfaces of the moving body 2. Furthermore, a magnetic plate 35 can be provided as a ferromagnetic body on the facing surface of the side plate 33 with the field coils. In the case, as the side gap control coil unit 6 of the three-phase core linear motor, one can be provided on the side surface of the moving body 2.

[0068] The lateral gap sensor 63 detects the size of the lateral gap, and is, for example, an infrared sensor. As the lateral gap sensor 63, any sensor can be used, and a non-contact sensor is preferable. In the present embodiment, the lateral gap sensor 63 is attached to one of the side gap control coil units 6, and can be directly or indirectly attached to the moving body 2 through other members.

[0069] Further, the lateral distance can be controlled by other members. For example, in Figure 3 In the modification shown, the rollers 7 rotatably provided in contact with the side plates 33 are provided one each on both side surfaces of the moving body 2. In addition, in Figure 3 In the embodiment, the same symbols are attached to the same members as those of the embodiment, and detailed description is omitted.

[0070] From the viewpoint of suppressing dust generation, it is desirable to control the lateral distance with a non-contact type restriction member such as the coil unit 6 and the lateral distance sensor 63. However, the force applied in the width direction is relatively small when the moving body 2 is carried, and therefore a contact type restriction member such as the roller 7 can also be used.

[0071] The control device 8 supplies a drive current to the travel control coil unit 4, the upper distance control coil unit 5, and the lateral distance control coil unit 6, respectively, moves the moving body 2 in the moving direction, and controls the sizes of the upper distance and the lateral distance. As shown in Figure 4 The control device 8 includes a travel control device 81, an upper distance control device 83, and a lateral distance control device 85, as shown in

[0072] As shown in Figure 5 The travel control device 81 includes a travel control section 811, a phase calculator 812, proportional integral (PI) control sections 813a and 813b, an inverse d-q conversion section 814, a power amplifier 815, an analog to digital (A / D) converter 816, and a d-q conversion section 817.

[0073] The phase calculator 812 is inputted with a pole signal mp indicating the magnetic field of the permanent magnets 35n and 35s detected by the pole sensor 433 and a position signal po indicating the current position of the moving body 2 detected by the position sensor 431. The phase calculator 812 calculates the phase of the magnetic field of the magnetic plate 35 based on the pole signal mp and the position signal po, and outputs a phase signal ph indicating the phase of the magnetic field of the magnetic plate 35 to the inverse d-q conversion section 814 and the d-q conversion section 817.

[0074] The travel control section 811 calculates a target phase of the magnetic field of the magnetic plate 35 based on a moving instruction po ref, and a position signal po input from the position sensor 431, to calculate a target position and a target speed of the moving body 2. The travel control coil unit 4 generates a thrust in the direction of movement with respect to the magnetic plate 35 in proportion to the q-axis current value Aiq. Therefore, the travel control section 811 outputs the q-axis current command Aiq ref to the PI control section 813a in order to supply the q-axis current as a drive current to the travel control coil unit 4. On the other hand, the travel control device 81 does not supply the d-axis current to the travel control coil unit 4. That is, the travel control section 811 outputs the d-axis current command Aid ref .

[0075] The PI control section 813a and the PI control section 813b convert the q-axis current command Aiq ref to a q-axis voltage command AVq ref and the d-axis current command Aid ref to a d-axis voltage command AVd ref by performing PI operations, respectively. The reverse d-q conversion section 814 performs d-q reverse conversion on the q-axis voltage command AVq ref and the d-axis voltage command AVd ref based on the phase signal ph to calculate a u-phase voltage command AVu ref , a v-phase voltage command AVv ref , and a w-phase voltage command AVw ref , and outputs them to the power amplifier 815.

[0076] The power amplifier 815 supplies the required u-phase voltage AVu, v-phase voltage AVv, and w-phase voltage AVw to the u-phase coil 41u, v-phase coil 41v, and w-phase coil 41w of the travel control coil unit 4, respectively, based on the u-phase voltage command AVu ref , v-phase voltage command AVv ref , and w-phase voltage command AVw ref .

[0077] Thus, the travel control coil unit 4 generates a magnetic field whose phase is shifted by about 90° from the magnetic field generated by the magnetic plate 35, and the moving body 2 is moved in the required direction of movement by the magnetic force generated between the travel control coil unit 4 and the magnetic plate 35.

[0078] Furthermore, feedback control is ideally implemented during the movement control of the moving body 2. Specifically, the A / D converter 816 reads the values ​​of the u-phase voltage AVu, v-phase voltage AVv, and w-phase voltage AVw output from the power amplifier 815, and converts them into u-phase current values ​​Aiu, v-phase current values ​​Aiv, and w-phase current values ​​Aiw. The dq conversion unit 817 performs dq conversion on the u-phase current values ​​Aiu, v-phase current values ​​Aiv, and w-phase current values ​​Aiw based on the phase signal ph, calculating the q-axis current value Aiq and the d-axis current value Aid. The q-axis current command Aiq is then used. ref and d-axis current command Aid ref Correction is achieved using the q-axis current value Aiq and the d-axis current value Aid.

[0079] like Figure 6 As shown, the upper spacing control device 83 includes an upper spacing control unit 831, a phase calculator 832, a PI control unit 833a and a PI control unit 833b, an inverting dq converter 834, a power amplifier 835, an A / D converter 836, and a dq converter 837.

[0080] The phase calculator 832 receives the magnetic pole signal mp and the position signal po. Based on the magnetic pole signal mp and the position signal po, the phase calculator 832 outputs the phase signal ph to the inverting dq converter 834 and the dq converter 837. Alternatively, the phase calculator 812 and the phase calculator 832 can be separately installed in the travel control device 81 and the upper spacing control device 83, respectively, or they can be combined into a single phase calculator.

[0081] The upper spacing control unit 831 calculates a correction value for the upper spacing based on the upper spacing signal tgap, which indicates the current upper spacing size, input from the upper spacing sensor 53, the d-axis current value Bid, input from the dq conversion unit 837, and a predetermined set value. The vertical attraction or repulsion force generated by the upper spacing control coil unit 5 relative to the magnetic plate 35 is related to the d-axis current value Bid. Therefore, in order to supply d-axis current as a drive current to the upper spacing control coil unit 5, the upper spacing control unit 831 sends the d-axis current command Bid... ref The output is sent to the PI control unit 833b. On the other hand, the upper pitch control device 83 does not supply q-axis current to the upper pitch control coil unit 5. That is, the upper pitch control unit 831 outputs a q-axis current command Biq with a value of 0 to the PI control unit 833a. ref .

[0082] PI control units 833a and 833b perform PI calculations respectively to convert the q-axis current command Biq. ref Convert to q-axis voltage command BVq refd-axis current command Bid ref Convert to d-axis voltage command BVd ref The inverting dq converter 834 converts the q-axis voltage command BVq based on the phase signal ph. ref and d-axis voltage command BVd ref Perform dq inverse conversion to calculate the u-phase voltage command BVu. ref Phase V voltage command BVv ref And the w-phase voltage command BVw ref And output to the power amplifier 835.

[0083] The 835 power amplifier is based on the u-phase voltage command BVu. ref Phase V voltage command BVv ref And the w-phase voltage command BVw ref The required phase u voltage BVu, phase v voltage BVv and phase w voltage BVw are supplied to the phase u coil 51u, phase v coil 51v and phase w coil 51w of the upper spacing control coil unit 5, respectively.

[0084] Therefore, the upper spacing control coil unit 5 generates a magnetic field in a direction parallel to the magnetic field generated by the magnetic plate 35, that is, a magnetic field whose phase is consistent with the N of the magnetic field generated by the magnetic plate 35. Through the magnetic force generated by the upper spacing control coil unit 5 and the magnetic plate 35, the upper spacing is maintained at the required size.

[0085] Furthermore, feedback control is ideal for upper spacing control. Specifically, the A / D converter 836 reads the values ​​of the u-phase voltage BVu, v-phase voltage BVv, and w-phase voltage BVw output from the power amplifier 835 and converts them into u-phase current values ​​Biu, v-phase current values ​​Biv, and w-phase current values ​​Biw. The dq conversion unit 837 performs dq conversion on the u-phase current values ​​Biu, v-phase current values ​​Biv, and w-phase current values ​​Biw based on the phase signal ph, calculating the q-axis current value Biq and the d-axis current value Bid. The q-axis current command is Biq. ref and d-axis current command Bid ref Correction is achieved using the q-axis current value Biq and the d-axis current value Bid.

[0086] Here, the magnitude of the drive current supplied to the upper spacing control coil unit 5, i.e., the d-axis current, is ideally controlled in a manner that matches the weight of the movable part as a whole, consisting of the moving body 2 and the components fixed to the moving body 2, with the attraction force between the upper spacing control coil unit 5 and the magnetic plate 35. That is, in the upper spacing control coil unit 5, it is ideal to perform so-called zero-power control. In this embodiment, specifically, the components fixed to the moving body 2 include the travel control coil unit 4, the position / magnetic pole sensor 43, the upper spacing control coil unit 5, the upper spacing sensor 53, the lateral spacing control coil unit 6, the lateral spacing sensor 63, the bucket suspended to the moving body 2, and the object to be transported mounted on the bucket. Let G be the weight of the entire movable part, including the moving body 2 and the components fixed to the moving body 2. Let P1 be the attraction force generated by the travel control coil unit 4, and P2 be the attraction force generated by one upper spacing control coil unit 5. Then, when P2 becomes {(G-P1) / (number of upper spacing control coil units 5)}, the attraction force between the upper spacing control coil unit 5 and the magnetic plate 35 is matched. By controlling the upper spacing by matching the weight of the entire movable part and the attraction force between the upper spacing control coil unit 5 and the magnetic plate 35, the value of the drive current supplied to the upper spacing control coil unit 5 can be substantially zero, thereby suppressing power consumption. That is, ideally, the upper spacing is controlled to a value where the drive current is substantially zero, rather than a value commanded by the upper device 80, etc.

[0087] like Figure 7 As shown, the side spacing control device 85 includes a side spacing control unit 851, a PI control unit 853, a power amplifier 855, and an A / D converter 856.

[0088] The lateral spacing control unit 851 calculates a correction value for the lateral spacing based on the lateral spacing signal sgap, which represents the current lateral spacing size, input from the lateral spacing sensor 63, and a predetermined set value. Then, the lateral spacing control unit 851 sends a current command Ci... ref The output is sent to the PI control unit 853.

[0089] The PI control unit 853 performs PI calculations to convert the current command Ci... ref Convert to voltage command CV ref And output to power amplifier 855.

[0090] Power amplifier 855 based on voltage command (CV) ref The required voltage CV is supplied to the excitation coil 61 of the side spacing control coil unit 6.

[0091] Thus, by controlling the magnetic force generated between the lateral spacing control coil unit 6 and the side plate 33, the lateral spacing is maintained at the required size.

[0092] Furthermore, feedback control is ideal for lateral spacing control. Specifically, the A / D converter 856 reads the voltage CV output by the power amplifier 855 and converts it into a current value Ci. The current command Ci... ref Correction is made using the current value Ci.

[0093] The side spacing control device 85 described above shows the structure when each side spacing control coil unit 6 is a single-phase AC electromagnet or a DC electromagnet. As mentioned above, the side spacing control coil unit 6 can also be a coil unit for a three-phase cored linear motor.

[0094] As illustrated in the examples already shown, this invention is not limited to the structure of the embodiments shown in the accompanying drawings, and various modifications or applications can be made without departing from the technical concept of this invention.

Claims

1. A conveying device, comprising: Moving body; A top plate is disposed above the moving body, spaced apart from it; At least one magnetic plate, comprising a plurality of permanent magnets, the plurality of permanent magnets being arranged parallel to a predetermined direction of movement on the lower surface of the top plate in an adjacent manner with different polarities; The travel control coil unit includes a plurality of excitation coils, which are disposed on the upper surface of the moving body along a predetermined magnetic plate of the at least one magnetic plate and spaced apart from the predetermined magnetic plate; At least two upper spacing control coil units, including a plurality of excitation coils, the plurality of excitation coils being disposed on the upper surface of the moving body at a distance from the magnetic plate along the predetermined magnetic plate of the at least one magnetic plate; and The control device supplies drive current to the travel control coil unit and the at least two upper spacing control coil units respectively, causing the moving body to move along the moving direction, and controls the spacing between the magnetic plate and the at least two upper spacing control coil units, i.e., the upper spacing. The travel control coil unit and the at least two upper spacing control coil units are arranged on the same line along the specified magnetic plate. The control device supplies d-axis current as the driving current to the at least two upper-spaced control coil units. The d-axis current is a current that generates a magnetic field in a direction parallel to the direction of the magnetic field generated by the predetermined magnetic plate. The travel control coil unit is supplied with a q-axis current orthogonal to the d-axis current as the driving current.

2. The conveying device according to claim 1, wherein the at least two upper spacing control coil units are respectively disposed at the front and rear of the moving direction, separated by the travel control coil unit.

3. The conveying device according to claim 1 further includes a position sensor, which detects the position of the moving body in the direction of movement.

4. The conveying device according to claim 1 further includes at least one upper spacing sensor, wherein the at least one upper spacing sensor detects the size of the upper spacing.

5. The conveying device according to claim 4, wherein the at least one upper spacing sensor comprises at least two upper spacing sensors, the at least two upper spacing sensors being disposed at the front and rear of the moving direction respectively, separated by the travel control coil unit.

6. The conveying device according to claim 1 further includes a pair of side plates, the side plates being disposed on the side of the moving body at a distance from the moving body.

7. The conveying device according to claim 6 further includes at least one lateral spacing control coil unit, comprising an excitation coil disposed on the side of the moving body at a distance from the side plate. At least the side plate facing the excitation coil is a strongly magnetic material. The control device supplies current to the at least one side spacing control coil unit and controls the distance between the at least one side spacing control coil unit and one of the side plates, i.e., the side spacing.

8. The conveying device according to claim 7 further includes a lateral spacing sensor, wherein the lateral spacing sensor detects the size of the lateral spacing.

9. The conveying device according to claim 6 further includes a roller, the roller being disposed on the side of the movable body and abutting against the side plate in a rotatable manner.

10. The conveying device according to claim 1, wherein the control device supplies the drive current to the at least two upper spacing control coil units in a manner that matches the gravity of the movable part as a whole, consisting of the moving body and the member fixed to the moving body, and the attraction force between the at least two upper spacing control coil units and the same or different magnetic plates as the specified magnetic plates.

11. A control method for a conveying device, The conveying device is the conveying device as described in claim 1. The control method of the conveying device supplies q-axis current as driving current to the travel control coil unit, causing the moving body to move along the travel direction. Furthermore, d-axis current is supplied as driving current to the at least two upper spacing control coil units, and the spacing between the magnetic plate and the at least two upper spacing control coil units, i.e., the upper spacing, is controlled. The d-axis current is the current that generates a magnetic field in a direction parallel to the direction of the magnetic field generated by the specified magnetic plate, and the q-axis current is the current orthogonal to the d-axis current.

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