Article transfer device

Abstract

An article transfer device (1) is provided with: a holding unit (21) that holds an article (2); an advancing / retreating drive unit (M3) that advances / retreats the holding unit (21); and a control unit that controls the advancing / retreating drive unit (M3). The control unit performs an advance / retreat operation, which is an operation in which the advance / retreat drive unit (M3) causes the holding unit (21) to protrude or retreat, on the basis of a reference command pattern, which is a time change pattern of a command value for a position, a speed, or an acceleration such that the acceleration varies in a stepped manner as time elapses. The moving average of the setting period of the command value indicated by the reference command mode is used as an output command value, and the advance and retreat driving part (M3) is controlled according to the output command value.

Description

Technical Field

[0001] The present invention relates to an article transfer device, which comprises a holding part for holding articles, an advance / retract drive part for advancing / retracting the holding part, and a control part for controlling the advance / retract drive part. Background Art

[0002] An example of an article transfer device as described above is disclosed in Japanese Patent Publication No. 2007-119136 (Patent Document 1). In the following description of the background art, the figure marks in Patent Document 1 are cited in parentheses. The article transfer device (13) of Patent Document 1 includes: a fork (24) that holds the article (9); an advance and retreat drive device (25) that advances and retreats the fork (24) to a retracted position and a protruding position; and an advance and retreat control unit (31c) that controls the advance and retreat drive device (25). When the fork (24) is moved from the retracted position to the protruding position, or when the fork (24) is moved from the protruding position to the retracted position, the advance and retreat control unit (31c) operates in accordance with the method described in Patent Document 1. Figure 6 The advance and retract speed curve shown controls the advance and retract speed of the fork (24). Summary of the invention

[0003] However, when the holding part (fork in Patent Document 1) is moved forward and backward, the holding part or the article held by the holding part may vibrate due to the change in the acceleration of the holding part. The vibration of the holding part or the article held by the holding part may cause a delay in the subsequent action (for example, the lifting action of the holding part) due to waiting until the vibration is recovered or an adverse effect on the article. Therefore, it is ideal to suppress such vibration as small as possible.

[0004] Therefore, it is desired to realize a technology that can easily suppress the vibration of the holding portion or the article held by the holding portion accompanying the forward and backward movement of the holding portion.

[0005] The article transfer device involved in the present disclosure is an article transfer device comprising a holding part for holding an article, an advance / retract drive part for moving the holding part forward and backward, and a control part for controlling the advance / retract drive part. The control part, in an advance / retract action which is an action of protruding or retracting the holding part by the advance / retract drive part, uses a moving average of the command values ​​shown in the reference command pattern over a set period as an output command value, based on a reference command pattern which is a time change pattern of the command values ​​of position, speed or acceleration in which the acceleration changes in a step-like manner with the passage of time, during an advance / retract action, and controls the advance / retract drive part according to the output command value.

[0006] According to this configuration, compared with the case where the advancing and retreating driving unit is controlled according to the command value indicated by the reference command mode, the change (jump) of the acceleration of the holding unit during the advancing and retreating movement of the holding unit can be suppressed to be small, thereby also suppressing the change of the acceleration acting on the article held in the holding unit. Therefore, according to this configuration, it is easy to suppress the vibration of the holding unit or the article held in the holding unit accompanying the advancing and retreating movement of the holding unit.

[0007] Further features and advantages of the article transfer device will become apparent from the following description of the embodiments described with reference to the accompanying drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0008] Figure 1 It is a perspective view showing the transport vehicle according to the embodiment. Figure 2 It is a side view which shows the transport vehicle which concerns on embodiment. Figure 3 It is a front view which shows the transport vehicle which concerns on embodiment. Figure 4 This is a control block diagram involved in the implementation scheme. Figure 5 : is a diagram showing an example of a reference instruction pattern and a pattern after sine wave processing. Figure 6 : is a diagram showing an example of a reference instruction pattern and a pattern after moving average processing. Figure 7 It is a perspective view showing a transport vehicle according to another embodiment. DETAILED DESCRIPTION

[0009] The embodiment of the article transfer device is described based on the accompanying drawings. Figure 2 and Figure 3 As shown, the article transfer device 1 is provided on a transport vehicle 100 (here, an unmanned transport vehicle) that transports an article 2. The article 2 is, for example, a FOUP (Front Opening Unified Pod) that accommodates semiconductor wafers.

[0010] Figures 1 to 3 The transport vehicle 100 of the present embodiment shown is configured as follows. The transport vehicle 100 includes a travel portion 10 that travels along a travel path 40 and a main body portion 20 connected to the travel portion 10. Here, the main body portion 20 is supported on the travel portion 10 in a state of being arranged at the lower side Z2 relative to the travel portion 10. The article 2 is transported by the transport vehicle 100 in a state of being accommodated in the main body portion 20.

[0011] The travel path 40 is formed by travel rails 41 (here, a pair of travel rails 41 arranged at intervals along the width direction Y). The direction along the travel path 40 is the travel direction X, and the width direction Y is a direction perpendicular to the travel direction X when viewed in the up-down direction along the up-down direction Z (vertical direction) (here, a horizontal direction perpendicular to the travel direction X). The travel unit 10 has travel wheels 11 that roll on the travel surface (here, the upper surface) of the travel rails 41, and the travel wheels 11 are rotationally driven by the travel drive unit M1 (for example, an electric motor such as a servo motor), so that the travel unit 10 travels along the travel rails 41. Here, the travel rails 41 are suspended and supported from the ceiling 3, and the travel path 40 is formed along the ceiling 3. That is, the transport vehicle 100 of this embodiment is a ceiling transport vehicle.

[0012] like Figure 2 and Figure 3 As shown in FIG. 1 , the article transfer device 1 includes a holding portion 21 for holding the article 2. In the present embodiment, the holding portion 21 holds the article 2 from the upper side Z1. Figure 3 In the example shown, the holding portion 21 holds the article 2 by supporting the supported portion 2a (here, the flange portion) formed on the upper portion of the article 2 with the support member 21a. The holding method of the article 2 by the holding portion 21 is not limited to this, and for example, it may be as described later. Figure 7 As in the example shown, the holding portion 21 supports the article 2 from the lower side Z2 or the holding portion 21 clamps the article 2 from both sides in the horizontal direction.

[0013] In the present embodiment, the holding portion 21 is configured to perform a holding operation for holding the article 2 and a holding release operation for releasing the holding of the article 2. Figure 3 In the example shown, in the holding operation performed by the holding portion 21, at least a portion of the supporting member 21a is moved toward the lower side Z2 of the supported portion 2a. As a result, the article 2 can be held by the holding portion 21 (specifically, the supported portion 2a can be supported by the supporting member 21a). In addition, in the holding release operation performed by the holding portion 21, the supporting member 21a is retracted from the lower side Z2 of the supported portion 2a.

[0014] The article transfer device 1 includes a holding drive unit M4 (for example, an electric motor such as a servo motor) for driving the holding unit 21 (specifically, the support member 21a), and the holding operation performed by the holding unit 21 and the holding release operation performed by the holding unit 21 are performed by driving the holding drive unit M4. Figure 3In the example shown, the holding portion 21 includes a pair of supporting members 21a, and the holding driving portion M4 is configured so that the pair of supporting members 21a are moved closer to and away from each other. In addition, in the holding operation performed by the holding portion 21, at least a portion of each of the pair of supporting members 21a is moved toward the lower side Z2 of the supported portion 2a. In addition, in the holding release operation performed by the holding portion 21, each of the pair of supporting members 21a is retracted from the lower side Z2 of the supported portion 2a.

[0015] exist Figure 3 In the example shown, the holding operation by the holding portion 21 is performed by bringing the pair of supporting members 21a closer to each other, and the holding release operation by the holding portion 21 is performed by moving the pair of supporting members 21a away from each other. Different from such a configuration, a configuration may be adopted in which the holding operation by the holding portion 21 is performed by moving the pair of supporting members 21a away from each other, and the holding release operation by the holding portion 21 is performed by moving the pair of supporting members 21a closer to each other.

[0016] In the present embodiment, the article transfer device 1 includes a lifting drive unit M2 (for example, an electric motor such as a servo motor) that lifts and lowers the holding unit 21. Here, "lifting and lowering" means lifting and lowering a portion that serves as a reference relative to the article transfer device 1 (hereinafter referred to as a "reference portion"). In the present embodiment, the reference portion of the article transfer device 1 is a portion of the article transfer device 1 that is fixed to the main body 20. Therefore, the lifting drive unit M2 lifts and lowers the holding unit 21 relative to the main body 20.

[0017] The article transfer device 1 includes a lifting device 22 for lifting the holding portion 21, and the lifting drive unit M2 operates the lifting device 22 to lift the holding portion 21. Figure 2 In the example shown, the lifting device 22 is configured in such a manner that the holding portion 21 is lifted by winding a rope body 23 (belt or wire, etc.) that suspends the holding portion 21, and the holding portion 21 is lowered by releasing the rope body 23. One end of the rope body 23 is connected to the holding portion 21, and the other end of the rope body 23 is fixed to a reel not shown. The lifting drive unit M2 winds the rope body 23 around the reel by rotating the reel in one rotation direction, and releases the rope body 23 from the reel by rotating the reel in the other rotation direction.

[0018] When the transport vehicle 100 is traveling along the travel path 40, the holding portion 21 is arranged at a reference height H1 (see Figure 2 The reference height H1 is, for example, the upper limit position of the lifting range of the holding portion 21 of the lifting device 22 (in other words, the height in a state where the rope body 23 is wound to the maximum). Figure 2In the illustrated example, the reference height H1 is a height at which the holding portion 21 and the article 2 held by the holding portion 21 are stored in the main body 20 .

[0019] When the transport vehicle 100 (specifically, the article transfer device 1) performs a transfer operation of the article 2 between the holding portion 21 and the transfer target location 4, the holding portion 21 is arranged at a transfer height H2 (see FIG. 1 ) corresponding to the transfer target location 4. Figure 2 ). The transfer object part 4 is, for example, a loading port of a processing device that processes the article 2 (or the contents contained in the article 2), an entry and exit port of a storage device that stores the article 2, a storage rack that temporarily stores the article 2, etc. The holding action of the holding part 21 on the article 2 or the holding release action of the holding part 21 on the article 2 is performed in a state where the holding part 21 is configured at the transfer height H2. The transfer height H2 is set in accordance with the height of the transfer object part 4. Figure 2 In the illustrated example, the transfer height H2 is a height lower than the reference height H1.

[0020] like Figure 3 and Figure 4 As shown, the article transfer device 1 includes an advance / retract drive unit M3 (e.g., an electric motor such as a servo motor) for advancing / retracting the holding unit 21. Here, "advance / retract" means to advance / retract relative to the above-mentioned reference portion of the article transfer device 1. Therefore, the advance / retract drive unit M3 advances / retracts the holding unit 21 relative to the main body 20.

[0021] The article transfer device 1 includes an advance-retract device 24 for advancing and retracting the holding portion 21, and the advance-retract drive portion M3 operates the advance-retract device 24 to advance and retract the holding portion 21. The advance-retract device 24 is configured, for example, in a manner that advances and retracts the holding portion 21 while still maintaining the posture of the holding portion 21 (in other words, in a manner that moves the holding portion 21 in parallel between a retracted position and a protruding position). The retracted position and the protruding position will be described later. Such an advance-retract device 24 can be configured, for example, using a sliding mechanism (linear motion mechanism). In the present embodiment, the lifting device 22 supports the holding portion 21 so that it can be lifted and lowered freely, and the advance-retract device 24 supports the lifting device 22 so that it can be advanced and retracted freely. Moreover, the advance-retract device 24 is configured in a manner that advances and retracts the holding portion 21 supported by the lifting device 22 by advancing and retracting the lifting device 22. Figure 3 In the illustrated example, the advancing and retreating device 24 is configured to advance and retreat the lifting device 22 while maintaining the posture of the lifting device 22 (in other words, to move the lifting device 22 in parallel).

[0022] The advance and retreat direction D of the holding portion 21 using the advance and retreat drive portion M3 may be in the direction along the horizontal plane or in the direction inclined relative to the horizontal plane. In the present embodiment, the advance and retreat direction D is in the direction along the horizontal plane. In addition, in the present specification, "along the plane" is not limited to being parallel to the plane, but also includes being slightly inclined relative to the plane. Therefore, the advance and retreat direction D is not limited to being parallel to the horizontal plane, but may be in the direction slightly inclined relative to the horizontal plane. Figures 1 to 3 In the example shown, the advancing and retreating direction D is a direction parallel to the width direction Y.

[0023] When the transport vehicle 100 is traveling along the travel path 40, the holding portion 21 is disposed at the retracted position. The retracted position is a position retracted toward the reference portion of the article transfer device 1. In the present embodiment, the retracted position is a position where the holding portion 21 overlaps with the travel portion 10 when viewed in the vertical direction along the vertical direction Z. Figure 1 The holding portion 21 is not shown, but Figure 1 The state where the holding portion 21 holding the article 2 is arranged at the retracted position is shown.

[0024] When the transport vehicle 100 (specifically, the article transfer device 1) performs a transfer operation of the article 2 between the holding portion 21 and the transfer target portion 4, and the transfer target portion 4 to which the article 2 is transferred is arranged at a position overlapping with the travel path 40 when viewed in the vertical direction, the holding portion 21 is arranged at the retracted position. On the other hand, when the transfer target portion 4 to which the article 2 is transferred is arranged at a position offset in the width direction Y relative to the travel path 40 when viewed in the vertical direction, the holding portion 21 is arranged at the protruding position. The protruding position is a position protruding to the side opposite to the above-mentioned reference portion side of the article transfer device 1. In the present embodiment, the protruding position is a position where the holding portion 21 overlaps with the transfer target portion 4 when viewed in the vertical direction. Figure 3 The state where the holding portion 21 is arranged in the protruding position is shown.

[0025] The article transfer device 1 includes a control unit 30 (see Figure 4 ). In the present embodiment, the control unit 30 also controls the travel drive unit M1, the lifting drive unit M2, and the holding drive unit M4. The control unit 30, for example, includes a CPU (Central Processing Unit) and other processing devices and peripheral circuits such as a memory. The various functions of the control unit 30 are realized, for example, by the cooperation of hardware such as a processing device and a program executed on the hardware. The control unit 30 is configured to control at least the forward and backward drive unit M3. It is also possible that a control unit different from the control unit 30 controls at least any one of the travel drive unit M1, the lifting drive unit M2, and the holding drive unit M4.

[0026] The control unit 30 may also be divided into a plurality of control units that can communicate with each other. In addition, the control unit 30 may be entirely provided in a device (hereinafter referred to as a "main device") provided with a control object such as an advance and retreat drive unit M3, or may be entirely provided in a device (hereinafter referred to as an "external device") provided outside the main device and capable of communicating with the main device. Alternatively, the control unit 30 may be partially provided in the main device and partially provided in the external device. In addition, in the present embodiment, the main device is a transport vehicle 100.

[0027] The various technical features of the control unit 30 described below can also be applied to the operation method of the control unit 30 or the program for making the computer function as the control unit 30. Such an operation method or program, and a recording medium (computer-readable recording medium such as an optical disk or flash memory) recording such a program are also disclosed in this specification. The program for making the computer function as the control unit 30 is provided, for example, by a recording medium recording the program or via a communication network, and the provided program is stored in a storage device that can be referenced by the computer.

[0028] The control unit 30 controls the travel drive unit M1 to make the travel unit 10 perform a travel action along the travel path 40. The control unit 30 controls the lifting drive unit M2 to make the lifting device 22 perform a lifting action to lift the holding unit 21. The lifting action includes a lifting action to lift the holding unit 21 and a lowering action to lower the holding unit 21. In the present embodiment, the control unit 30 controls the lifting drive unit M2 in the lifting action of the holding unit 21 to gradually increase the lifting speed of the holding unit 21 toward the target speed, and then perform a constant speed lifting action to maintain the lifting speed of the holding unit 21 at the target speed, and then gradually reduce the lifting speed of the holding unit 21 from the target speed to stop the holding unit 21. The control unit 30 controls the advance and retreat drive unit M3 to make the advance and retreat device 24 perform an advance and retreat action to advance and retreat the holding unit 21. The advance and retreat action includes a protruding action to protrude the holding unit 21 and a retracting action to retract the holding unit 21. The control unit 30 controls the holding drive unit M4 to cause the holding unit 21 to perform a holding operation and a holding release operation.

[0029] When the transport vehicle 100 (specifically, the article transfer device 1) is causing the transport vehicle 100 to transfer an article 2 between the holding portion 21 and the transfer target portion 4, and the transfer target portion 4 is arranged at a position offset in the width direction Y relative to the travel path 40 when viewed in the up and down directions, the control unit 30 controls the travel drive unit M1, the lifting drive unit M2, the forward and backward drive unit M3, and the holding drive unit M4, so that the transport vehicle 100 moves as follows.

[0030] When transferring the article 2 from the holding portion 21 to the transfer target location 4, the control unit 30 causes the travel unit 10 to perform a travel operation to cause the transport vehicle 100 to travel to the same position as the transfer target location 4 in the travel direction X, while the holding portion 21 holding the article 2 is arranged at the retracted position at the reference height H1. Thereafter, the control unit 30 causes the advancing and retreating device 24 to perform a protruding operation to move the holding portion 21 holding the article 2 from the retracted position to the protruding position, and then causes the lifting device 22 to perform a lifting operation (here, a descending operation) to lift the holding portion 21 from the reference height H1 to the transfer height H2, and then causes the holding portion 21 to perform a holding release operation of the article 2. Then, the control unit 30 causes the lifting device 22 to perform a lifting operation (here, a rising operation) to lift the holding portion 21 not holding the article 2 from the transfer height H2 to the reference height H1, and then causes the advancing and retreating device 24 to perform a retracting operation to retract the holding portion 21 from the protruding position to the retracted position.

[0031] When transferring the article 2 from the transfer target location 4 to the holding portion 21, the control unit 30 causes the travel unit 10 to perform a travel operation to cause the transport vehicle 100 to travel to the same position as the transfer target location 4 in the travel direction X, while the holding portion 21 not holding the article 2 is arranged at the retracted position at the reference height H1. Thereafter, the control unit 30 causes the advancing and retreating device 24 to perform a protruding operation to move the holding portion 21 not holding the article 2 from the retracted position to the protruding position, and then causes the lifting device 22 to perform a lifting operation (here, a descending operation) to lift the holding portion 21 from the reference height H1 to the transfer height H2, and then causes the holding portion 21 to perform a holding operation of the article 2. Then, the control unit 30 causes the lifting device 22 to perform a lifting operation (here, a rising operation) to lift the holding portion 21 holding the article 2 from the transfer height H2 to the reference height H1, and then causes the advancing and retreating device 24 to perform a retracting operation to retract the holding portion 21 from the protruding position to the retracted position.

[0032] Although the details are omitted, when the transport vehicle 100 (specifically, the article transfer device 1) is operated to transfer the article 2 between the holding portion 21 and the transfer target portion 4, and the transfer target portion 4 is arranged at a position overlapping with the travel path 40 when viewed in the up and down directions, the control unit 30 operates the transport vehicle 100 in the same manner as described above, except that the advance and retreat device 24 is not operated to perform the protruding action of the holding portion 21 and the retracting action of the holding portion 21.

[0033] Thus, when the control unit 30 transfers the article 2 between the holding unit 21 and the transfer target portion 4, the advance / retract device 24 performs an advance / retract motion of the holding unit 21. Then, in order to minimize the vibration of the holding unit 21 or the article 2 held by the holding unit 21 accompanying the advance / retract motion of the holding unit 21, the control unit 30 controls the advance / retract drive unit M3 as described below in the advance / retract motion as the motion of protruding or retracting the holding unit 21 by the advance / retract drive unit M3. In addition, the following configuration may be adopted: the control unit 30 controls the advance / retract drive unit M3 as described below for either the protruding motion of protruding the holding unit 21 or the retracting motion of retracting the holding unit 21, instead of the two motions of the protruding motion of protruding the holding unit 21 and the retracting motion of retracting the holding unit 21.

[0034] In the advance and retreat action, which is an action of protruding or retracting the holding part 21 through the advance and retreat drive part M3, the control part 30 outputs the command value based on the moving average of the command value during the setting period shown in the reference command pattern, which is a time change pattern of the command value of the position, speed or acceleration such that the acceleration changes in a step-like manner with the passage of time. Here, the acceleration also includes deceleration (negative acceleration). Then, the control part 30 controls the advance and retreat drive part M3 according to the output command value. Thus, it is possible to use the reference command pattern such as the acceleration changing in a step-like manner, and at the same time change the speed of the holding part 21 in such a way that the change of the acceleration of the holding part 21 becomes smooth. That is, by taking into account the calculation of the jump (rate of change of acceleration), even if the time change pattern of the command value such as the acceleration changing smoothly is not derived, the speed of the holding part 21 can be changed in such a way that the change of the acceleration of the holding part 21 becomes smooth.

[0035] The control unit 30 outputs the command value as the command value obtained by performing a moving average process on the reference command pattern. Specifically, the control unit 30 outputs the command value as the command value obtained by performing a moving average process on the time series data of the reference command pattern for a set period (moving average time). The moving average process is, for example, an unweighted simple moving average process. The control unit 30 obtains the reference command pattern from other control units such as an upper-level control unit or obtains the reference command pattern by referring to a storage unit.

[0036] The reference command mode may be any one of a time variation pattern of a position command value such that the acceleration changes in a step-like manner with the passage of time (hereinafter referred to as a "reference position command mode"), a time variation pattern of a speed command value such that the acceleration changes in a step-like manner with the passage of time (hereinafter referred to as a "reference speed command mode"), and a time variation pattern of an acceleration command value such that the acceleration changes in a step-like manner with the passage of time (hereinafter referred to as a "reference acceleration command mode"). When the reference command mode is the reference position command mode, the output command value is a position command value, when the reference command mode is the reference speed command mode, the output command value is a speed command value, and when the reference command mode is the reference acceleration command mode, the output command value is an acceleration command value.

[0037] In the case where the output command value is a position command value, the control unit 30 controls the advance and retreat drive unit M3 through position control based on the output command value. In the case where the output command value is a speed command value, the control unit 30 controls the advance and retreat drive unit M3 through speed control based on the output command value. In the case where the output command value is an acceleration command value, the control unit 30 controls the advance and retreat drive unit M3 through acceleration control based on the output command value. In addition, the control of the advance and retreat drive unit M3 by the control unit 30 according to the output command value may also be control of the advance and retreat drive unit M3 based on a command value that is a derivative or integral of the output command value. For example, in the case where the output command value is a speed command value, the control unit 30 may also be configured to control the advance and retreat drive unit M3 through position control based on a position command value generated by integrating the output command value.

[0038] The control unit 30 controls the advance and retreat drive unit M3 according to the output command value, for example, through feedback control. In the feedback control, the control unit 30 generates a drive command based on the deviation between the feedback value and the command value (the output command value or the command value obtained by differentiating or integrating the output command value), and controls the advance and retreat drive unit M3 to output a driving force (for example, torque) corresponding to the drive command. The feedback value is detected, for example, by a detector (for example, an encoder) provided in the advance and retreat drive unit M3. The control unit 30 may also be configured to control the advance and retreat drive unit M3 according to the output command value through feedforward control or through a combination of feedback control and feedforward control.

[0039] The control unit 30 may also be configured to control the advance / retract drive unit M3 according to the command value indicated by the reference command pattern under specific conditions. The control content for the case where the control unit 30 controls the advance / retract drive unit M3 according to the command value indicated by the reference command pattern is the same as the case where the control unit 30 controls the advance / retract drive unit M3 according to the output command value as the moving average of the reference command pattern, but the "output command value" is replaced by the "command value indicated by the reference command pattern", and thus the detailed description is omitted.

[0040] In the present embodiment, the control unit 30 controls the advance / retract drive unit M3 during the advance / retract motion of the holding unit 21 so as to make the speed of the holding unit 21 approach the target speed Vt (see Figure 5 , Figure 6 ) is gradually increased, the speed of the holding unit 21 is maintained at the target speed Vt, and thereafter, the speed of the holding unit 21 is gradually reduced from the target speed Vt to stop the holding unit 21. Figure 5 In the example shown, the period from time t1 to time t2 is a period during which the speed of the holding unit 21 gradually increases toward the target speed Vt, the period from time t2 to time t3 is a period during which the speed of the holding unit 21 is maintained at the target speed Vt, and the period from time t3 to time t4 is a period during which the speed of the holding unit 21 gradually decreases from the target speed Vt. In this embodiment, the reference command mode is the reference speed command mode. Figure 5 and Figure 6 The speed indicated by the dashed line in represents the reference instruction pattern (reference speed instruction pattern) when the speed of the holding unit 21 is changed as described above. Figure 5 and Figure 6 The acceleration indicated by the one-dot chain line in φ represents a temporal change in the acceleration corresponding to the reference speed command pattern (specifically, a first-order differential value of the speed indicated by the reference speed command pattern).

[0041] exist Figure 5 The speed and acceleration shown by the solid lines in FIG. 1 represent the time changes of the speed and acceleration when the sine wave processing is performed to change the step-like acceleration change into the sine wave-like acceleration change. By performing the sine wave processing in this way, the speed of the holding part 21 can be changed in a manner that the acceleration change of the holding part 21 becomes smooth, but if Figure 5 As shown, the maximum value (absolute value, the same below) of the acceleration of the holding portion 21 exceeds the value in Figure 5 Specifically, the maximum value of the acceleration corresponding to the reference speed instruction pattern shown by the single-dot chain line in FIG. 1 is π / 2 times larger. Such an increase in the maximum value of the acceleration of the holding portion 21 may, for example, cause an adverse effect on the article 2 held in the holding portion 21, and thus the scope of application of such a technology may be limited.

[0042] In contrast, the control unit 30 controls the forward / reverse drive unit M3 according to the output command value which is the moving average of the command values ​​indicated in the reference command mode (reference speed command mode in this embodiment). Figure 6 As shown, the maximum value of the acceleration of the holding portion 21 can be made not to exceed the value in Figure 6 The maximum value of the acceleration corresponding to the reference speed instruction pattern shown by the single-dot chain line in FIG. 1 and the speed of the holding unit 21 are changed in such a way that the change of the acceleration of the holding unit 21 becomes smooth. Figure 6 , the speed indicated by the solid line represents the time variation of the output command value (here, the speed command value) as the moving average of the reference command pattern, and the acceleration indicated by the solid line represents the time variation of the acceleration corresponding to the speed indicated by the solid line.

[0043] Figure 6 The time t11, time t13, time t15 and time t17 in Figure 5 In the example, the time t1, the time t2, the time t3 and the time t4 correspond to each other. Figure 6 , the length of the period from time t11 to time t12, the length of the period from time t13 to time t14, the length of the period from time t15 to time t16, and the length of the period from time t17 to time t18 are consistent with the length of the set period (moving average time) involved in the moving average. Figure 6 As shown, when the advance / retract drive unit M3 is controlled according to the output command value of the moving average as the reference command pattern, the time until the holding unit 21 reaches the target position (retracted position or protruding position) (i.e., the time required for the advance / retract movement of the holding unit 21) becomes longer than the set period when the advance / retract drive unit M3 is controlled according to the command value shown in the reference command pattern. Figure 6 In the example shown, the time required for the forward and backward movement of the holding unit 21 is extended from the time from time t11 to time t17 to the time from time t11 to time t18. If the setting period is extended, the change of the acceleration of the holding unit 21 can be made smoother, but in this way, the time required for the forward and backward movement of the holding unit 21 becomes longer accordingly.

[0044] The control unit 30 may not change the length of the set period, but considering that the time required for the advance and retreat action of the holding unit 21 increases the length of the set period as described above, the control unit 30 may change the length of the set period as described below. In addition, the change of the length of the set period includes making the length of the set period zero (in other words, controlling the advance and retreat drive unit M3 according to the command value indicated by the reference command mode).

[0045] For example, the control unit 30 can be configured such that when the holding unit 21 holds the article 2, the control unit 30 extends the set period compared to when the holding unit 21 does not hold the article 2. In this case, Figure 4 As shown, it is suitable to be the following configuration: the article transfer device 1 includes a determination unit 31 for determining whether the holding unit 21 holds the article 2, and the control unit 30 changes the length of the set period as described above based on the determination result of the determination unit 31. For example, the determination unit 31 or the weight determination unit 32 described later is implemented by the control unit 30 (specifically, the processing unit) executing a program. In addition, Figure 4 The control unit 30, the determination unit 31, and the weight determination unit 32 described later are at least logically or conceptually distinguished, but not necessarily physically distinguished. For example, the determination unit 31 and the weight determination unit 32 may be a common determination unit.

[0046] When the article 2 is transferred from the holding portion 21 to the transfer target portion 4 (hereinafter referred to as "unloading transfer"), the protruding action of the holding portion 21 is performed in a state where the holding portion 21 holds the article 2, and the retracting action of the holding portion 21 is performed in a state where the holding portion 21 does not hold the article 2. In addition, when the article 2 is transferred from the transfer target portion 4 to the holding portion 21 (hereinafter referred to as "lifting transfer"), the protruding action of the holding portion 21 is performed in a state where the holding portion 21 does not hold the article 2, and the retracting action of the holding portion 21 is performed in a state where the holding portion 21 holds the article 2. Therefore, for example, the following configuration can be adopted: the determination portion 31 determines whether the holding portion 21 holds the article 2 during the forward and backward action (protruding action or retracting action) based on whether it is unloading transfer or lifting transfer. When the control unit 30 is configured to cause the transport vehicle 100 to transport the article 2 in response to a command from another control unit such as a superior control unit, the determination unit 31 may determine whether the article 2 is to be transported by unloading or lifting based on the command.

[0047] The determination method of the determination unit 31 is not limited to the above method, and for example, the following configuration may be adopted: the determination unit 31 determines whether the holding unit 21 holds the article 2 based on an index related to the driving force of the lifting drive unit M2 in the lifting action (for example, the output torque or current value when the lifting drive unit M2 is a motor). In addition, the following configuration may be adopted: the determination unit 31 determines whether the holding unit 21 holds the article 2 based on detection information of a sensor (a presence sensor for detecting the presence of the article 2 or a weight sensor for detecting the weight of the article 2) provided in the holding unit 21.

[0048] In the above-mentioned configuration, the control unit 30 extends the set period when the holding unit 21 holds the article 2 as compared to the case where the holding unit 21 does not hold the article 2, but the control unit 30 may set the length of the set period to zero when the holding unit 21 does not hold the article 2. In this case, the control unit 30 is configured as follows: in the forward and backward movement in the state where the holding unit 21 holds the article 2, the forward and backward drive unit M3 is controlled according to the output command value, and in the forward and backward movement in the state where the holding unit 21 does not hold the article 2, the forward and backward drive unit M3 is controlled according to the command value indicated by the reference command mode.

[0049] However, the holding portion 21 or the article 2 held by the holding portion 21 may vibrate in a manner that is different from the weight of the article 2. Therefore, the length of the setting period that can effectively reduce the vibration may be different from the weight of the article 2. In consideration of this, the control portion 30 may be configured to change the setting period (specifically, change the length of the setting period, the same below) in accordance with the weight of the article 2 held by the holding portion 21. In this case, Figure 4 As shown, it is suitable to be the following configuration: the article transfer device 1 is provided with a weight determination unit 32 for determining the weight of the article 2 held by the holding unit 21, and the control unit 30 changes the setting period as described above based on the determination result using the weight determination unit 32. In addition, in the case where the article 2 is a container for accommodating substrates such as semiconductor wafers, the weight of the article 2 changes in accordance with the number of substrates accommodated. For example, it is possible to be the following configuration: the weight determination unit 32 determines the weight of the article 2 held by the holding unit 21 during the lifting and lowering operation of the holding unit 21 by the lifting and lowering drive unit M2.

[0050] The following configuration is possible: when the control unit 30 is configured to make the transport vehicle 100 perform the transport operation of the article 2 in accordance with the instruction from other control units such as the superior control unit, and when the information on the weight of the article 2 can be obtained based on the instruction, the weight determination unit 32 determines the weight of the article 2 held by the holding unit 21 based on the instruction. In addition, similar to the determination method of the determination unit 31 described above, the following configuration is possible: the weight determination unit 32 determines the weight of the article 2 held by the holding unit 21 based on an indicator related to the driving force of the lifting drive unit M2 in the lifting operation or based on the detection information of the weight sensor provided on the holding unit 21.

[0051] For example, the following configuration may be adopted: a setting period by weight is obtained in advance as an appropriate setting period corresponding to the weight of the article 2 through experiments, etc., and the control unit 30 changes the setting period to a setting period by weight corresponding to the weight of the article 2 held by the holding unit 21. In addition, the control unit 30 may also be configured to simply extend the setting period in stages or continuously as the weight of the article 2 held by the holding unit 21 increases. In addition, the characteristics of the article 2 that serve as a basis for changing the setting period are not limited to the weight of the article 2. For example, the control unit 30 may also be configured to change the setting period in accordance with characteristics other than the weight of the article 2 held by the holding unit 21 (for example, the tolerance of vibration).

[0052] However, if the set period is changed during the advance and retreat movement of the holding unit 21, the output command value becomes discontinuous before and after the length of the set period is changed, so that the advance and retreat movement of the holding unit 21 may become unstable. In view of this, it is appropriate that the control unit 30 is configured to change the set period during a period other than the advance and retreat movement. In the present embodiment, the period other than the advance and retreat movement includes a period during the lifting and lowering movement of the holding unit 21 by the lifting drive unit M2, a period during the holding movement by the holding unit 21, and a period during the holding release movement by the holding unit 21. Therefore, the control unit 30 can be configured to change the set period during the lifting and lowering movement of the holding unit 21 by the lifting drive unit M2, a period during the holding movement by the holding unit 21, or a period during the holding release movement by the holding unit 21. In addition, the control unit 30 can also be configured to change the set period during the lifting and lowering movement of the holding unit 21 by the lifting drive unit M2. That is, the control unit 30 may be configured not to change the set period during the holding operation by the holding unit 21 or during the holding release operation by the holding unit 21 .

[0053] In the present embodiment, when unloading and transferring are performed, the projecting action of the holding portion 21, the descending action of the holding portion 21, the holding release action by the holding portion 21, the ascending action of the holding portion 21, and the retracting action of the holding portion 21 are performed in sequence. In this case, the setting period is changed to be shorter during the descending action of the holding portion 21, the holding release action by the holding portion 21, or the ascending action of the holding portion 21, so that when the holding portion 21 holds the article 2, the setting period can be extended compared to the case where the holding portion 21 does not hold the article 2. The following configuration is possible: when the setting period is changed during unloading and transferring or during the descending action of the holding portion 21, for example, the setting period is changed during the descent of the holding portion 21 based on the above-mentioned constant speed lifting action.

[0054] In addition, in the present embodiment, when lifting and transferring is performed, the projecting action of the holding portion 21, the descending action of the holding portion 21, the holding action by the holding portion 21, the ascending action of the holding portion 21, and the retracting action of the holding portion 21 are sequentially performed. In this case, the set period is changed to be longer during the descending action of the holding portion 21, the holding action by the holding portion 21, or the ascending action of the holding portion 21, so that when the holding portion 21 holds the article 2, the set period can be extended compared to the case where the holding portion 21 does not hold the article 2. The following configuration can be adopted: when the set period is changed during lifting and transferring or during the ascending action of the holding portion 21, for example, the set period is changed during the ascending of the holding portion 21 based on the above-mentioned constant speed lifting action after the article 2 is separated from the transfer target portion 4 due to the ascending of the holding portion 21.

[0055] [Other implementation methods] (1) In the above-mentioned embodiment, the following configuration is described as an example: the lifting device 22 supports the holding portion 21 so as to be able to be raised and lowered, and the advancing and retreating device 24 supports the lifting device 22 so as to be able to be advanced and retreated. However, the present disclosure is not limited to such a configuration, and the following configuration may be adopted: the advancing and retreating device 24 supports the holding portion 21 so as to be able to be advanced and retreated, and the lifting device 22 supports the advancing and retreating device 24 so as to be able to be raised and retreated. In this case, the lifting device 22 is configured in such a manner that the holding portion 21 supported by the advancing and retreating device 24 is raised and lowered.

[0056] (2) In the above-mentioned embodiment, the article transfer device 1 is described as an example in which the article transfer device 1 includes the lifting drive unit M2 for lifting the holding unit 21. However, the present disclosure is not limited to such a configuration, and the article transfer device 1 may not include the lifting drive unit M2. That is, the article transfer device 1 may not include the lifting device 22. In this case, for example, the device provided at the transfer target portion 4 of the article 2 includes a device for lifting the article 2.

[0057] (3) In the above-mentioned embodiment, the following configuration is described as an example: the transport vehicle 100 provided with the article transfer device 1 is a ceiling transport vehicle that travels along the travel path 40 formed along the ceiling 3. However, the present disclosure is not limited to such a configuration, and the article transfer device 1 may also be provided in a transport vehicle 100 of other types. Figure 7 The case where the transport vehicle 100 provided with the article transfer device 1 is a stacker crane is shown. Figure 7 In the drawings, parts having the same functions as those of the transport vehicle 100 of the above-described embodiment are denoted by the same reference numerals as those of the above-described embodiment.

[0058] Figure 7The transport vehicle 100 shown in the figure includes: a travel unit 10 that travels along a travel track 41 provided on a floor surface; a mast 12 that is erected on the travel unit 10; and a lifting platform 13 that is raised and lowered along the mast 12. The holding unit 21 is supported on the lifting platform 13. By driving the travel drive unit M1, the upper end of the mast 12 is guided by a guide track 42 provided on the ceiling side, and at the same time, the travel unit 10 travels along a travel path 40. The lifting device 22 is configured so that the lifting platform 13 is raised and lowered along the mast 12, and the lifting drive unit M2 operates the lifting device 22 to raise and lower the lifting platform 13 and the holding unit 21 supported on the lifting platform 13.

[0059] exist Figure 7 In the example shown, the holding portion 21 holds the article 2 from the lower side Z2. Specifically, the holding portion 21 holds the article 2 by supporting the bottom of the article 2 from the lower side Z2. The advancing and retreating device 24 is configured to allow the holding portion 21 to advance and retreat relative to the lifting platform 13. Figure 7 The advance and retreat drive unit M3 shown in the figure moves the advance and retreat device 24 to move the holding unit 21 forward and backward relative to the lifting platform 13. Figure 7 In the example shown, a drive unit corresponding to the holding drive unit M4 in the above-mentioned embodiment is not provided. Figure 7 In the illustrated example, for example, a shelf portion of a storage rack having a plurality of layers of shelf portions for storing articles 2 along the up-down direction Z is used as the transfer target location 4 .

[0060] In the case of unloading and transferring, the projecting action of the holding part 21, the descending action of the holding part 21, and the retracting action of the holding part 21 are performed in sequence. In this case, by changing the setting period to a shorter time during the descending action of the holding part 21, when the holding part 21 holds the article 2, the setting period can be extended compared to the case where the holding part 21 does not hold the article 2. In addition, in the case of lifting and transferring, the projecting action of the holding part 21, the ascending action of the holding part 21, and the retracting action of the holding part 21 are performed in sequence. In this case, by changing the setting period to a longer time during the ascending action of the holding part 21, when the holding part 21 holds the article 2, the setting period can be extended compared to the case where the holding part 21 does not hold the article 2.

[0061] In addition, the transport vehicle 100 provided with the article transfer device 1 is not limited to the mode of traveling along the travel track 41 such as a ceiling transport vehicle, a stacking crane, or other rail transport vehicles, and may also be a trackless transport vehicle such as an AGV (Automated Guided Vehicle) or an AMR (Autonomous Mobile Robot). In the case where the transport vehicle 100 is a trackless transport vehicle, the transport vehicle 100 travels along a travel path 40 that is not physically formed using a travel track, etc., but is virtually formed. For example, a plurality of detected objects such as two-dimensional codes or RF (Radio Frequency) tags are provided on the floor surface, and the travel path 40 is virtually formed in a manner of connecting the plurality of detected objects. It is also possible to have the following configuration: such a detected object is not provided on the floor surface, and the travel path 40 is virtually formed according to a route calculated based on the recognition result of the surrounding environment.

[0062] (4) In the above-mentioned embodiment, the article transfer device 1 is provided on the transport vehicle 100. However, the present disclosure is not limited to such a configuration, and the article transfer device 1 may be fixed to a floor or the like.

[0063] (5) In addition, the configurations disclosed in the above-mentioned embodiments can also be combined with the configurations disclosed in other embodiments (including the combination of the embodiments described as other embodiments) as long as no contradiction occurs. With regard to other configurations, the embodiments disclosed in this specification are merely illustrative in all points. Therefore, various changes can be made as appropriate without departing from the scope of the present disclosure.

[0064] [Summary of this embodiment] Hereinafter, the embodiments related to the article transfer device described above will be summarized as follows.

[0065] An article transfer device, which is an article transfer device comprising a holding portion for holding an article, an advance / retract drive portion for moving the holding portion forward / retract, and a control portion for controlling the advance / retract drive portion, wherein the control portion, in an advance / retract action which is an action of causing the holding portion to protrude or retract by the advance / retract drive portion, uses a reference command pattern which is a time change pattern of command values ​​of position, velocity or acceleration such that acceleration changes in a step-like manner with the passage of time, and uses a moving average of the command values ​​shown in the reference command pattern over a set period as an output command value, and controls the advance / retract drive portion according to the output command value.

[0066] According to this configuration, compared with the case where the advancing and retreating driving unit is controlled according to the command value indicated by the reference command mode, the change (jump) of the acceleration of the holding unit during the advancing and retreating movement of the holding unit can be suppressed to be small, thereby also suppressing the change of the acceleration acting on the article held in the holding unit. Therefore, according to this configuration, it is easy to suppress the vibration of the holding unit or the article held in the holding unit accompanying the advancing and retreating movement of the holding unit.

[0067] Here, preferably, there is further provided a determination unit for determining whether the holding unit holds the article, and the control unit extends the set period when the holding unit holds the article, compared to when the holding unit does not hold the article.

[0068] According to this configuration, when the holding portion holds an article, the setting period can be extended to reduce the change in acceleration acting on the article and suppress the vibration of the article. On the other hand, when the holding portion does not hold an article, the setting period can be shortened so that the time required for the advance and retreat action of the holding portion does not increase. Therefore, according to this configuration, the vibration of the article held by the holding portion can be suppressed to be small, and at the same time, the time required for the advance and retreat action of the holding portion can be suppressed from increasing.

[0069] In addition, it is suitable that there is also a determination unit for determining whether the aforementioned holding unit is holding the aforementioned article, and the aforementioned control unit controls the aforementioned advance and retreat drive unit according to the aforementioned output instruction value during the aforementioned advance and retreat movement in a state where the aforementioned holding unit is holding the aforementioned article, and controls the aforementioned advance and retreat drive unit according to the instruction value indicated by the aforementioned reference instruction mode during the aforementioned advance and retreat movement in a state where the aforementioned holding unit is not holding the aforementioned article.

[0070] According to this configuration, when the holding portion holds an article, by controlling the advance / retract drive portion according to the output command value that is the moving average of the command value indicated by the reference command pattern, the change in acceleration acting on the article can be suppressed to be small, and the vibration of the article can be suppressed to be small. On the other hand, when the holding portion does not hold an article, by controlling the advance / retract drive portion according to the command value indicated by the reference command pattern without taking a moving average, the time required for the advance / retract action of the holding portion can be shortened compared to the case where a moving average is taken. Therefore, according to this configuration, the vibration of the article held by the holding portion can be suppressed to be small, and at the same time, the time required for the advance / retract action of the holding portion can be suppressed from being prolonged.

[0071] Preferably, the device further comprises a weight determination unit for determining the weight of the article held by the holding unit, and the control unit changes the set period according to the weight of the article held by the holding unit.

[0072] According to this configuration, an appropriate setting period can be set according to the weight of the article held by the holding unit.

[0073] In addition, it is suitable that there is also a lifting drive unit for lifting the aforementioned holding unit, and the advance and retreat direction of the aforementioned holding unit using the aforementioned advance and retreat drive unit is along the direction of the horizontal plane, and the aforementioned control unit changes the aforementioned set period during the lifting and lowering action of the aforementioned holding unit performed by the aforementioned lifting drive unit.

[0074] According to this configuration, the set period can be changed by using the period in the lifting and lowering action of the holding part performed by the lifting and lowering driving part. Moreover, by changing the set period in the lifting and lowering action of the holding part performed by the lifting and lowering driving part, the set period can be kept unchanged during the advancing and retreating action of the holding part, thereby facilitating and stably performing the advancing and retreating action of the holding part.

[0075] The article transfer device according to the present disclosure only needs to achieve at least one of the above-mentioned effects. Description of Reference Numerals

[0076] 1: Article transfer device 2: Items 21: Maintaining Department 30: Control Department 31: Judgment Department 32: Weight determination unit D: forward and backward direction M2: Lifting drive unit M3: Advance and retraction drive unit.

Claims

1. An article transfer device comprising a holding unit for holding an article, an advance / retract drive unit for advancing / retracting the holding unit, and a control unit for controlling the advance / retract drive unit, The article transfer device has the following characteristics: In the forward / retractable action, which is the action of protruding or retracting the retaining portion through the forward / retractable driving portion, the control portion controls the forward / retractable driving portion according to the output command value, based on a reference command pattern, which is a time change pattern of the command value of the position, velocity or acceleration in which the acceleration changes in a step-like manner with the passage of time, and using the moving average of the command values ​​shown in the reference command pattern during a setting period as an output command value.

2. The article transfer device according to claim 1, wherein: further comprising a determination unit for determining whether the holding unit holds the article, The control unit extends the set period when the holding unit holds the article, compared to a case where the holding unit does not hold the article.

3. The article transfer device according to claim 1, wherein: further comprising a determination unit for determining whether the holding unit holds the article, The control unit controls the advance / retract drive unit according to the output instruction value during the advance / retract movement when the holding unit holds the article, and controls the advance / retract drive unit according to the instruction value shown in the reference instruction pattern during the advance / retract movement when the holding unit does not hold the article.

4. The article transfer device according to claim 1, wherein: further comprising a weight determination unit for determining the weight of the article held by the holding unit, The control unit changes the set period according to the weight of the article held by the holding unit.

5. The article transfer device according to any one of claims 2 to 4, wherein: The device further comprises a lifting driving unit for lifting the holding unit. The advancing and retreating direction of the holding portion by the advancing and retreating driving portion is along the horizontal plane. The control unit changes the set period during the lifting and lowering operation of the holding unit by the lifting and lowering driving unit.

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