Movable body control device and storage medium

Abstract

The invention provides a technology capable of easily adjusting a movable body such as a scanning frame or a workbench. The solution comprises: a unit 23 comprising a cylinder 21 and a piston 22; a subject support part (303) that moves in accordance with the relative movement of the cylinder (21) and the piston (22); a control board 30 that generates a control signal including a first pulse width W on the basis of an operation signal T1 input by a user's operation; and an oil amount adjustment unit (27) that adjusts the amount of oil contained in the cylinder (21) on the basis of the first pulse width (W), and the control plate (30) performs: determining the value of the gain (K) on the basis of the deviation amount (DM); calculating a second pulse width W2 based on the deviation amount DM and the determined value of the gain; when a next operation signal T2 is input, a control signal including a second pulse width W2 is generated, and an oil amount adjustment unit 27 adjusts the amount of oil in the cylinder 21 on the basis of the second pulse width W2.

Description

Technical Field

[0001] The present invention relates to a movable body control device for controlling a movable body, and a storage medium storing instructions for operating the movable body control device. Background Art

[0002] CT systems are known as medical devices for non-invasively imaging a subject. CT systems are widely used in medical facilities such as hospitals because they can acquire tomographic images of a subject in a short scanning time.

[0003] The CT system applies a predetermined voltage to the cathode and anode of the X-ray tube, generating X-rays. These X-rays pass through the subject and are detected by a detector. The CT system reconstructs a CT image of the subject based on the data detected by the detector.

[0004] Prior art literature

[0005] Patent Literature

[0006] Patent Document 1: Japanese Patent Application Laid-Open No. 2014-161392 Summary of the Invention

[0007] Problems to be solved by the invention

[0008] When imaging a subject using a CT system, the subject is placed on a table. After the subject is placed on the table, an operator adjusts the height of the table so that the imaging portion of the subject is properly positioned within the aperture of the gantry.

[0009] When adjusting the height of a worktable, the operator typically performs a rough adjustment and then fine-tunes the height. One known method for fine-tuning the height is micro-motion. In CT systems configured to enable fine-tuning using micro-motion, a control panel is provided for the operator to fine-tune the height of the worktable. When the operator operates the control panel, the height of the worktable is fine-tuned accordingly.

[0010] The worktable's vertical mechanism typically uses hydraulic or motor servo control. Motor servo control excels at fine-tuning and high-precision control, but is not good at outputting large forces and is also expensive. On the other hand, hydraulic control is inexpensive and good at outputting large forces, but suffers from the disadvantage of being poor at fine-tuning. Hydraulic control is often used for worktables in CT systems, where price is a priority. Hydraulic control uses a valve to adjust the flow rate of the working fluid (oil). When the operator operates the control panel, the valve opens and closes to adjust the height of the worktable. However, with hydraulic control, when the operator operates the control panel once, the change in the worktable's height corresponding to that single operation sometimes deviates from the desired value (target change). As a result, the operator must operate the control panel multiple times to adjust the worktable's height to the desired position, which takes time and places a heavy workload on the operator. To minimize this problem, the current practice is to adjust the valve flow rate for each worktable during the final stage of worktable manufacturing and inspection. However, valve flow rate adjustment is only performed under specific conditions (e.g., temperature). Therefore, when adjusting the height of the workbench under conditions different from the specific conditions, there is the following problem: the operator must operate the control panel multiple times to make the height of the workbench consistent with the desired position. In addition, by adjusting the flow rate of the valve during the workbench manufacturing inspection, the initial change in the height of the workbench is consistent with the desired value (target change), but if the workbench continues to be used, it is likely to gradually deviate from the desired value (target change), and there are limits to the flow rate adjustment of the valve during the workbench manufacturing inspection. To address this problem, workbench using hydraulic servo is known, but it is unrealistic to use a hydraulic servo mechanism for a workbench that requires low cost.

[0011] Furthermore, some CT systems are known to include a tilt mechanism capable of tilting the gantry. When this tilt mechanism utilizes hydraulic pressure, the operator may need to operate the control panel multiple times to adjust the gantry's tilt angle to the desired angle, further increasing the operator's burden.

[0012] Therefore, a technology that can easily adjust movable bodies such as a gantry and a stage is desired.

[0013] Technical Solution

[0014] A first aspect of the present invention is a movable body control device comprising: a unit including a cylinder and a piston, at least a portion of the piston being disposed within the cylinder, and wherein one of the cylinder and the piston is moved relative to the other by adjusting the amount of a working fluid within the cylinder;

[0015] a movable body that moves according to the relative movement of the cylinder and the piston;

[0016] a control unit that generates, based on a first operation signal input by a user operation for moving the movable body by a target change amount, a control signal including a first pulse width corresponding to the target change amount, so as to move the movable body by the target change amount;

[0017] a fluid amount adjustment unit that adjusts the amount of working fluid contained in the cylinder based on the first pulse width, and

[0018] The control unit performs:

[0019] By adjusting the amount of the working fluid in the cylinder, the movement amount of the movable body is determined;

[0020] determining a gain value based on an amount of deviation between the amount of movement of the movable body and the target amount of change;

[0021] calculating a second pulse width based on the offset and the determined gain value;

[0022] When a second operation signal for moving the movable body by a target change amount is input after the first operation signal, a control signal including the second pulse width is generated, and

[0023] The fluid amount adjustment unit adjusts the amount of the working fluid in the cylinder based on the second pulse width.

[0024] In addition, a second aspect of the present invention is a non-transitory computer-readable storage medium, which is included in a movable body control device or is capable of communicating with the movable body control device.

[0025] The movable body control device includes:

[0026] A unit comprising a cylinder and a piston, wherein at least a portion of the piston is disposed within the cylinder, and the cylinder and the piston are moved relative to each other by adjusting the amount of working fluid within the cylinder;

[0027] a movable body that moves according to the relative movement of the cylinder and the piston;

[0028] a control unit that generates, based on a first operation signal input by a user operation for moving the movable body by a target change amount, a control signal including a first pulse width corresponding to the target change amount, so as to move the movable body by the target change amount;

[0029] a fluid amount adjustment unit that adjusts the amount of working fluid contained in the cylinder based on the first pulse width, and

[0030] The control unit includes one or more processors,

[0031] The instructions contained in the storage device, when executed by the one or more processors, cause the one or more processors to perform:

[0032] By adjusting the amount of the working fluid in the cylinder, the movement amount of the movable body is determined;

[0033] determining a gain value based on an amount of deviation between the amount of movement of the movable body and the target amount of change;

[0034] calculating a second pulse width based on the offset and the determined gain value;

[0035] When a second operation signal for moving the movable body by a target change amount is input after the first operation signal, a control signal including the second pulse width is generated, and

[0036] The fluid amount adjustment unit adjusts the amount of the working fluid in the cylinder based on the second pulse width.

[0037] Beneficial effects

[0038] In the present invention, the gain value corresponding to the target change amount is determined based on the deviation between the movable body's movement amount and the target change amount. Therefore, the gain value is determined taking into account the actual deviation amount. Therefore, using the determined gain value, it is possible to calculate a second pulse width that reduces the deviation between the movable body's actual displacement amount and the target change amount. Furthermore, when the second operation signal is input, the movable body's movement amount is adjusted based on a control signal including the second pulse width. This allows the movable body's movement amount to be brought sufficiently close to the target change amount, thereby reducing the user's workload associated with movable body adjustment. BRIEF DESCRIPTION OF THE DRAWINGS

[0039] Figure 1 is a perspective view of the CT system 100 in the first embodiment.

[0040] Figure 2 It is an enlarged view of the operation panel 10 .

[0041] Figure 3 This is an explanatory diagram when the up button 12 is tapped.

[0042] Figure 4 This is an explanatory diagram when the down button 13 is tapped.

[0043] Figure 5 It is a block diagram of the workbench and the workbench control device.

[0044] Figure 6It is a block diagram of the workbench and the workbench control device.

[0045] Figure 7 1 is a diagram schematically showing the pulse width W and the lowering amount D of the table 300 corresponding to the tapping operation by the operator 401 .

[0046] Figure 8 It is an explanatory diagram of a case where the descending amount D of the table 300 deviates from the target change amount TW.

[0047] Figure 9 1 is a diagram showing the flow of operations of the workbench 300 when finely adjusting the height of the workbench 300 according to the present embodiment.

[0048] Figure 10 4 is a diagram showing the pulse width W and the lowering amount D of the table 300 corresponding to the operation of the operator 401 .

[0049] Figure 11 : is a flowchart of the method of calculating the pulse width W2 in step ST6.

[0050] Figure 12 This shows the flow when the pulse width is set to a fixed value.

[0051] Figure 13 is a graph showing the calculation results.

[0052] Figure 14 This is a diagram showing an example in which another operation of adjusting the height of the table is performed between operations T1 to T5.

[0053] Figure 15 This is an explanatory diagram when the forward tilt button 14 is tapped.

[0054] Figure 16 It is an explanatory diagram of the operation panel 10 in the second embodiment.

[0055] Figure 17 This is an explanatory diagram when the forward tilt button 14 is tapped.

[0056] Figure 18 This is an explanatory diagram when the rear tilt button 15 is tapped. DETAILED DESCRIPTION

[0057] Hereinafter, specific embodiments will be described, but the present invention is not limited to the following embodiments.

[0058] (First embodiment)

[0059] Figure 1 is a perspective view of the CT system 100 in the first embodiment.

[0060] The CT system 100 includes a gantry 200 and a workbench 300. The gantry 200 and the workbench 300 are disposed in a scanning room.

[0061] The gantry 200 has a hole 201 , and the subject 400 is conveyed to the hole 201 , where the subject 400 is scanned.

[0062] In addition, an operation panel 10 (see FIG. 1 ) which can be operated by an operator 401 is installed on the front of the scanning frame 200. Figure 2 ).

[0063] Figure 2 It is an enlarged view of the operation panel 10 .

[0064] The operation panel 10 includes a button section 11 on which control buttons are arranged and a display section 16. The button section 11 includes an up button 12 for raising the height of the workbench 300, a down button 13 for lowering the height of the workbench 300, and the like.

[0065] To roughly adjust the height of the work platform 300, the operator 401 presses and holds the up button 12 or the down button 13. For example, to continuously raise the height of the work platform 300, the operator 401 presses and holds the up button 12. If the up button 12 is pressed, the height of the work platform 300 continuously rises while the operator 401 holds the up button 12. On the other hand, to continuously lower the height of the work platform 300, the operator 401 presses and holds the down button 13. If the down button 13 is pressed, the height of the work platform 300 continuously descends while the operator 401 holds the down button 13.

[0066] When the operator 401 wants to finely adjust the height of the workbench 300 , the operator 401 performs the following operation (hereinafter referred to as “tapping operation”): presses the up button 12 or the down button 13 and then immediately releases the hand from the button 12 or 13 . Figure 3 This is an explanatory diagram when the up button 12 is tapped. Figure 3 The workbench 300 shown in the left half of the table represents the height of the workbench before the tapping operation of the ascending button 12. Figure 3 The workbench 300 shown in the right half of the table shows the height of the workbench after the tapping operation of the ascending button 12. The workbench 300 is set to rise by the target change amount TV by a single tapping operation. Figure 3 In the figure, the target change amount TV is exaggerated to make it easier to understand. However, in reality, the target change amount TV is approximately TV = 0.1 (mm) to 0.5 (mm). Therefore, the operator 401 can finely control the height increase of the workbench 300 by tapping the increase button 12.

[0067] on the other hand, Figure 4 This is an explanatory diagram when the down button 13 is tapped. Figure 4 The workbench 300 shown in the left half of the table represents the height of the workbench before the tapping operation of the lowering button 13. Figure 4 The workbench 300 shown in the right half of the is the height of the workbench after the tapping operation of the lowering button 13. The workbench 300 is lowered by the target change amount TW by a single tapping operation. Figure 4 In the figure, the target change amount TW is exaggerated to make it easier to understand, but in reality, the target change amount TW is approximately TW = 0.1 (mm) to 0.5 (mm). Therefore, by tapping the lowering button 13, the height of the workbench 300 can be finely controlled.

[0068] The display unit 16 of the operation panel 10 includes a display area 17 . The display area 17 is an area for displaying the current height of the work table 300 .

[0069] Therefore, the operator 401 can adjust the height of the workbench 300 while checking the current height of the workbench 300 on the display unit 16 by tapping the up button 12 or the down button 13 .

[0070] Next, a description will be given of a control device that controls the height of the workbench by receiving an operation from the operation panel 10 .

[0071] Figure 5 It is a block diagram of the workbench and the workbench control device.

[0072] The workbench 300 includes a base 301, legs 302, and a subject support 303. The subject support 303 supports a subject (such as a patient). The legs 302 connect the base 301 and the subject support 303. The legs 302 are configured to be extendable and retractable in the height direction of the workbench 300, and the legs 302 extend and retract in response to changes in the height of the workbench 300. In addition, the workbench 300 includes a workbench control device 500 for controlling the height of the workbench. The workbench control device 500 is described below.

[0073] The stage control device 500 includes a hydraulic device 20 for adjusting the height of the object support 303 .

[0074] The hydraulic device 20 includes: a unit 23, which includes a cylinder 21 and a piston 22; an oil tank 24; a supply pipe 25, which supplies the oil in the oil tank 24 to the cylinder 21; a discharge pipe 26, which discharges the oil in the cylinder 21 to the oil tank 24; and an oil quantity adjustment unit 27, which adjusts the oil quantity in the cylinder 21.

[0075] It should be noted that the oil pressure device 20 is installed on the workbench 300, but Figure 5 In order to facilitate understanding of the components of the hydraulic device 20, a portion of the components of the hydraulic device 20 is shown in the figure as extending from the workbench 300. Figure 5 In the figure, the unit 23 is shown enlarged in order to facilitate understanding of the structure of the unit 23 including the cylinder 21 and the piston 22.

[0076] Hereinafter, each component of the hydraulic system 20 will be described in sequence.

[0077] The unit 23 is configured such that at least a portion of the piston 22 is disposed within the cylinder 21, and by adjusting the amount of oil within the cylinder 21, one of the cylinder 21 and the piston 22 is moved relative to the other. For example, the piston 22 may be configured to reciprocate relative to the cylinder 21, the cylinder 21 may be configured to reciprocate relative to the piston 22, or the cylinder 21 and the piston 22 may be configured to reciprocate relative to each other. Furthermore, during the height adjustment of the subject support portion 303, the cylinder 21 and the piston 22 may be configured such that the angle α between the cylinder 21 and the piston 22 remains fixed, or such that the angle α continuously changes. By configuring the cylinder 21 and the piston 22 as described above, the height of the subject support portion 303 can be adjusted. The method for adjusting the height of the subject support portion 303 in this embodiment will be described in detail below.

[0078] In addition, the hydraulic device 20 includes: an oil tank 24; a supply pipe 25 that supplies the oil in the oil tank 24 to the cylinder 21; a discharge pipe 26 that discharges the oil in the cylinder 21 to the oil tank 24; and an oil amount adjustment unit 27 that adjusts the oil amount in the cylinder 21.

[0079] The oil quantity adjustment unit 27 includes a pump 28 and a valve 29. The pump 28 is configured to supply oil from the oil tank 24 to the cylinder 21 via the supply pipe 25. The valve 29 is configured to discharge the oil from the cylinder 21 via the discharge pipe 26 and return it to the oil tank 24. It should be noted that in this embodiment, oil is used as the operating fluid of the hydraulic device 20, but other fluids besides oil can also be used as the operating fluid.

[0080] The table control device 500 includes a control board 30 and an inverter 40. The control board 30 and the inverter 40 are configured to control the operation of the hydraulic system 20. The control board 30 and the inverter 40 will be described below.

[0081] The control board 30 generates a control signal including a control pulse width corresponding to the target change amount based on the operation signal for causing the subject support part 303 to be raised or lowered by the target change amount, so as to cause the subject support part 303 to be raised or lowered by the target change amount. The control board 30 has a storage device 37. The storage device 37 includes one or more storage media for storing programs, instructions executed by a processor, etc. The storage medium may, for example, be one or more non-temporary computer-readable storage media. The storage medium may, for example, include: a hard disk drive, a floppy disk drive, a compact disk read / write (CD-R / W) drive, a digital versatile disk (DVD) drive, a flash memory drive and / or a solid-state recording drive. It should be noted that in Figure 5 In the figure, the control board 30 is shown as including one storage device 37, but the control board 30 may also include multiple storage devices 37. Furthermore, the multiple storage devices 37 may be provided on the control board 30 or may be distributed on the control board 30 and other components outside the control board 30.

[0082] The control board 30 includes a converter 31. The converter 31 is connected to the operation panel 10. The converter 31 receives an operation signal SB0 inputted when the operator 401 operates the button 12 or 13.

[0083] For example, when the operator 401 long-presses the raising button 12 , the operation signal SB0 indicates the operation signal SB1 for continuously raising the height of the workbench 300 .

[0084] On the other hand, when the operator 401 taps the ascending button 12, the operation signal SB0 indicates the target change amount TV (reference number) for ascending the workbench 300. Figure 3 ) signal SB2. Figure 3 In order to make the target change amount TV easier to understand, the target change amount TV is exaggerated. However, in reality, the target change amount TV is a value of about TV=0.1 (mm) to 0.5 (mm).

[0085] Furthermore, when the operator 401 performs an operation of long-pressing the lowering button 13 , the operation signal SB0 indicates a signal SB3 for continuously lowering the height of the workbench 300 .

[0086] On the other hand, when the operator 401 taps the lowering button 13, the operation signal SB0 indicates a target change amount TW (refer to FIG. 1 ) for lowering the height of the workbench 300. Figure 4 ) signal SB4. Figure 4 In order to make the target change amount TW easier to understand, the target change amount TW is exaggeratedly shown, but in reality, the target change amount TW is a value of approximately TW=0.1 (mm) to 0.5 (mm).

[0087] It should be noted that the target change amount TV when raising the height of the table 300 is the same as the target change amount TW when lowering the height of the table 300 (ie, TV=TW). However, TV≠TW may also be satisfied.

[0088] Upon receiving an operation signal SB0 from button 12 or 13, converter 31 converts the voltage of operation signal SB0 and outputs converted voltage signals SB01 (SB11, SB21, SB31, SB41). Converted voltage signal SB11 contains an instruction to continuously raise the height of workbench 300, while converted voltage signal SB21 contains an instruction to raise the height of workbench 300 by a target change amount TV. Furthermore, converted voltage signal SB31 contains an instruction to continuously lower the height of workbench 300, while converted voltage signal SB41 contains an instruction to lower the height of workbench 300 by a target change amount TW.

[0089] The control board 30 further includes a processor 32. The processor 32 generates a control signal for controlling the oil quantity adjustment unit 27 of the hydraulic device 20 based on the signal SB01 received from the converter 31. Figure 5 In the figure, the control board 30 is shown as including one processor 32, but the control board 30 may also include multiple processors 32. Furthermore, the multiple processors 32 may be provided on the control board 30 or may be distributed on the control board 30 and other components outside the control board 30.

[0090] When the processor 32 receives a signal SB11 containing an instruction for continuously raising the height of the workbench 300 from the converter 31, it generates a control signal SC11 for continuously supplying oil to the cylinder 21. The control signal SC11 is supplied to the buffer 33, and the control signal SC111, which has been subjected to prescribed processing in the buffer 33, is supplied to the inverter 40. Upon receiving the control signal SC111, the inverter 40 supplies the AC signal SD1 from the AC source 41 to the pump 28. Based on the AC signal SD1, the pump 28 continuously supplies oil from the oil tank 24 to the cylinder 21. Therefore, the cylinder 21 moves in the arrow direction A relative to the piston 22, and as a result, the subject support 303 continuously rises. In this way, the subject support 303 constitutes a movable body that moves according to the relative movement of the cylinder 21 and the piston 22.

[0091] Furthermore, upon receiving signal SB21 from converter 31 containing an instruction to raise the height of table 300 by a target change amount TV, processor 32 generates control signal SC12 for supplying an amount of oil corresponding to target change amount TV to cylinder 21. This control signal SC12 is a pulse signal SP, and its pulse width Q represents the duration corresponding to target change amount TV. For example, pulse width Q = 330 ms. This control signal SC12 is supplied to buffer 33, where, after undergoing specified processing, control signal SC121 is supplied to inverter 40. Upon receiving control signal SC121, inverter 40 supplies AC signal SD2 from AC source 41 to pump 28 for a period corresponding to pulse width Q = 330 ms. Based on AC signal SD2, pump 28 supplies an amount of oil corresponding to pulse width Q (= 330 ms) from oil tank 24 to cylinder 21. Thus, pump 28 can adjust the amount of oil contained in cylinder 21 based on pulse width Q (= 330 ms). As a result, the air cylinder 21 is finely adjusted in the arrow direction A, and the object supporting portion 303 is moved upward by the target change amount TV.

[0092] In addition, when the processor 32 receives a signal SB31 including an instruction for continuously lowering the height of the workbench 300 from the converter 31, it generates a control signal SC21 for continuously supplying oil to the cylinder 21. The control signal SC21 is supplied to the buffer 34, and the control signal SC211, which has been subjected to predetermined processing in the buffer 34, is supplied to the TFT 35. When the control signal SC211 is supplied, the TFT 35 becomes conductive. When the TFT 35 becomes conductive, a predetermined reference voltage Ref is applied to the valve 29, and the valve 29 opens. At this time, while the operator 401 presses the descending button 13, the TFT 35 remains conductive. Therefore, the valve 29 discharges the oil in the cylinder 21 to the oil tank 24. Therefore, the cylinder 21 moves in the direction of the arrow B, and as a result, the subject support 303 continuously descends.

[0093] Furthermore, upon receiving signal SB41 from converter 31 containing an instruction to lower the height of table 300 by a target change amount TW, processor 32 generates control signal SC22 for discharging an amount of oil corresponding to target change amount TW from cylinder 21. This control signal SC22 is a pulse signal SP, and the pulse width W of control signal SC22 represents the time corresponding to target change amount TW. For example, pulse width W = 330 ms. This control signal SC12 is supplied to buffer 33, where, after undergoing predetermined processing, control signal SC221 is supplied to TFT 35. When control signal SC221 is supplied, TFT 35 turns on. When TFT 35 turns on, a predetermined reference voltage Ref is applied to valve 29, causing valve 29 to open. At this time, TFT 35 remains on only for the time corresponding to pulse width W = 330 ms. Consequently, an amount of oil corresponding to pulse width W is discharged from cylinder 21 to oil tank 24, adjusting the oil level within cylinder 21. Therefore, the air cylinder 21 is finely adjusted in the arrow direction B, and as a result, the subject support 303 is lowered by the target change amount TW.

[0094] In addition, the workbench control device 500 includes a potentiometer 42. The potentiometer 42 outputs an analog signal SE indicating a voltage corresponding to the rise or fall of the subject support 303 by adjusting the amount of oil in the cylinder 21. The ADC 36 converts the analog signal SE into a digital signal SF and outputs it to the processor 32. Based on the digital signal SF received from the ADC 36, the processor 32 calculates the current height of the workbench 300 through the button operation of the operator 401. The processor 32 outputs a digital signal SG indicating the current height of the workbench 300 to the converter 31. The converter 31 adjusts the voltage of the digital signal SG received from the processor 32 and sends the voltage-adjusted signal SH to the display unit 16. The signal SH includes information indicating the current height of the workbench 300. Therefore, the display unit 16 displays the current height of the workbench 300 based on the signal SH. Therefore, the operator 401 can recognize the current height of the workbench 300 in real time by viewing the display unit 16.

[0095] The stage control device 500 is configured as described above. Next, in this embodiment, an example of a procedure in which the operator 401 adjusts the height of the stage 300 while operating the button unit 11 when imaging a subject will be described.

[0096] After the operator 401 places the subject 400 on the table 300 (refer to Figure 1 ), adjust the height of the workbench 300.

[0097] First, the operator 401 presses and holds the up button 12 to adjust the work platform 300 to a suitable height for filming. While the up button 12 is pressed, the work platform 300 continues to rise, allowing the operator 401 to move the work platform 300 closer to the desired height. Furthermore, if the height of the work platform 300 is too high, the operator 401 presses and holds the down button 13. While the down button 13 is pressed, the work platform 300 continues to descend, allowing the operator 401 to quickly lower the work platform 300 to near the desired position.

[0098] After roughly positioning the height of the workbench 300, the operator 401 finely adjusts the height of the workbench 300. Here, consider a case where the operator 401 wants to finely adjust the workbench 300 so as to be lower than the current height.

[0099] It should be noted that, in order to clarify the difference between this embodiment and the conventional method, the conventional method of finely adjusting the height of the table 300 will be described first.

[0100] (1) Fine-tuning method of the workbench height using existing methods

[0101] Hereinafter, a conventional method for fine-tuning a workbench will be described, taking as an example an operator 401 fine-tuning a workbench while repeatedly performing a tapping operation on the down button 13 of the operation panel 10. Figure 6 and Figure 7 The fine-tuning of the existing method is described. Figure 6 express Figure 5 But in the block diagram Figure 5 The following table also includes symbols that are not used in the following description of the fine adjustment of the workbench. Therefore, in order to facilitate the understanding of the accompanying drawings, Figure 5 The figure with unnecessary symbols removed is as Figure 6 . Figure 7 The pulse width W and the descending amount D of the workbench 300 corresponding to the tapping operation of the operator 401 are schematically shown.

[0102] First, the operator 401 performs a tapping operation T1 on the down button 13 to lower the workbench 300 by a predetermined target change amount. Figure 7 When the tapping operation T1 is performed, as shown in Figure 6 As shown, the target change amount TW (reference Figure 4) and inputs it to converter 31. Upon receiving operation signal SB4, converter 31 converts the voltage of operation signal SB4 and outputs a voltage-converted signal SB41. Voltage-converted signal SB41 includes an instruction to lower the height of worktable 300 by the target change amount TW.

[0103] When the processor 32 receives the signal SB41 including the instruction to lower the height of the work table 300 by the target change amount TW from the converter 31, it generates a control signal SC22 for discharging the amount of oil corresponding to the target change amount TW from the cylinder 21. The control signal SC22 is a pulse signal SP, and the pulse width W of the control signal SC22 is a fixed value. Figure 7 In the figure, an example of pulse width W of W = 330 ms is shown, but W may be a value different from 330 ms. A control signal SC22 including pulse width W (= 330 ms) is supplied to buffer 34, and a control signal SC221, which has undergone predetermined processing in buffer 34, is supplied to TFT 35. When control signal SC221 is supplied, TFT 35 turns on. When TFT 35 turns on, a predetermined reference voltage Ref is applied to valve 29, causing valve 29 to open. At this time, TFT 35 remains on only for a time corresponding to pulse width W (= 330 ms). Therefore, an amount of oil corresponding to pulse width W is discharged from cylinder 21 to oil tank 24. As a result, cylinder 21 is finely adjusted in the direction of arrow B, resulting in the lowering of worktable 300. Figure 7 The descent amount D of the table 300 corresponding to the operation T1 is shown. Here, the target change amount TW of the descent amount D of the table 300 is 0.5 mm, and the operation T1 is shown such that the descent amount D matches the target change amount TW.

[0104] Likewise, each time the tapping operations T2, T3, T4, ... are performed, the table 300 can be lowered by 0.5 mm at a time.

[0105] However, depending on the use environment of the scanning frame, the lowering amount D of the workbench 300 may sometimes deviate from the target change amount TW (refer to Figure 8 ).

[0106] Figure 8 It is an explanatory diagram of a case where the descending amount D of the table 300 deviates from the target change amount TW.

[0107] exist Figure 8 In the case where the operator 401 performs a tapping operation T1 on the down button 13 (an operation to lower the workbench 300 by the target change amount TW), as in Figure 7As described in , the processor 32 outputs a control signal with a pulse width W (=330 ms). The pulse width W=330 ms represents a pulse width that ideally lowers the stage 300 by a target change amount TW (eg, 0.5 mm).

[0108] However, in Figure 8 In the figure, the workbench 300 is lowered by a value that deviates from the target change amount TW (for example, 0.7 mm). In this way, the amount of descent D of the workbench 300 is affected by the working environment of the workbench and is sometimes inconsistent with the target change amount TW. Similarly, the operator 401 continues to operate T2, T3, T4..., but the amount of descent D is inconsistent with the target change amount TW. Therefore, operations T1 to T4 should ideally be operations that reduce the height of the workbench 300 by the target change amount TW, but in reality, even if operations T1 to T4 are performed, the amount of descent D of the workbench 300 deviates from the target change amount TW. Therefore, there is a problem that the operator 401 spends time in aligning the workbench 300 to the desired height, and the workload of the operator 401 increases.

[0109] Therefore, the inventors of this application have conducted intensive research and have developed a method for quickly reducing the deviation DM between the actual descent D and the target change TW to zero (or close to zero) even when the actual descent D of the worktable 300 deviates from the target change TW during fine-tuning of the height of the worktable 300. The method for fine-tuning the height of the worktable 300 in this embodiment is described below.

[0110] (2) Method for fine-tuning the workbench height in this embodiment

[0111] refer to Figure 9 A method for fine-tuning the stage according to this embodiment will be described.

[0112] Figure 9 1 is a diagram showing the flow of operations of the workbench 300 when finely adjusting the height of the workbench 300 according to the present embodiment.

[0113] It should be noted that, when necessary, reference will be made to Figure 6 and Figure 10 right Figure 9 Provide explanation. Figure 6 is a block diagram of the workbench control device 500, Figure 10 The pulse width W and the descending amount D of the table 300 corresponding to the operation of the operator 401 are shown.

[0114] In step ST1, the processor 32 waits for a tap operation T1 of the down button 13 (refer to Figure 10 ) When the operator 401 performs a tap operation T1 on the down button 13, the process proceeds to step ST2.

[0115] In step ST2, as Figure 6 As shown, an operation signal SB4 for lowering the height of the workbench 300 by a target change amount TW is output from the operation panel 10 and input to the converter 31. Here, the target change amount TW is described as TW=0.5mm, but TW can also be set to a value less than 0.5mm, for example, it can be set to a value less than 0.1mm. When the converter 31 receives the operation signal SB4, it converts the voltage of the operation signal SB4 and outputs the voltage-converted signal SB41. The voltage-converted signal SB41 is a signal containing an instruction for lowering the height of the workbench 300 by a target change amount TW. The processor 32 receives the signal SB41 containing an instruction for lowering the height of the workbench 300 by a target change amount TW from the converter 31, and generates a control signal SC22 containing a pulse width W=W1 based on the signal SB41. The control signal SC22 is a pulse signal SP. As shown Figure 10 As shown, the pulse width W1 corresponding to the operation T1 is W1 = 330 ms. After the control signal SC22 is generated, the process proceeds to step ST3.

[0116] In step ST3, the height of the workbench 300 is finely adjusted based on the control signal SC22. Specifically, the height of the workbench 300 is finely adjusted as follows. Figure 6 As shown, the control signal SC22 is supplied to the buffer 34, and the control signal SC221 after being subjected to predetermined processing in the buffer 34 is supplied to the TFT 35. When the control signal SC221 is supplied, the TFT 35 becomes conductive. When the TFT 35 becomes conductive, a predetermined reference voltage Ref is applied to the valve 29, and the valve 29 opens. At this time, the TFT 35 maintains the conductive state only for a time corresponding to the pulse width W1 (= 330 ms). Therefore, the amount of oil corresponding to the pulse width W1 is discharged from the cylinder 21 to the oil tank 24. Therefore, the cylinder 21 moves in the direction of arrow B, and the specimen support 303 descends, resulting in that the height of the workbench 300 is finely adjusted.

[0117] In step ST4, the height of the workbench 300 is displayed. Specifically, the height of the workbench 300 is displayed as follows.

[0118] The potentiometer 42 outputs an analog signal SE indicating a voltage corresponding to the descent of the subject support 303 by adjusting the amount of oil in the cylinder 21. The ADC 36 converts the analog signal SE into a digital signal SF and outputs it to the processor 32. The processor 32 calculates the current height of the workbench 300 corresponding to the operation T1 of the operator 401 based on the digital signal SF received from the ADC 36. The processor 32 outputs a digital signal SG indicating the current height of the workbench 300 to the converter 31. The converter 31 adjusts the voltage of the digital signal SG received from the processor 32 and sends the voltage-adjusted signal SH to the display 16. The signal SH includes information indicating the current height of the workbench 300. Therefore, the display 16 can display the current height of the workbench 300 based on the signal SH. Therefore, the operator 401 can recognize the current height of the workbench 300 in real time by viewing the display 16.

[0119] In step ST5 , the processor 32 calculates the actual descending amount D of the table 300 based on the digital signal SE received from the ADC 36 . Figure 10 The amount of descent D = D1 of the table 300 corresponding to the operation T1 is shown. Here, D1 = 1.0 mm. After the amount of descent D = D1 (= 1.0 mm) is determined, the process proceeds to step ST6.

[0120] In step ST6, the processor 32 uses the pulse width W1 used in the tapping operation T1 to calculate the pulse width W2 used when lowering the stage in the next tapping operation T2. ​​The pulse width W2 is calculated using the following formula (1).

[0121] W2=W1-W1*K*DM(1)

[0122] Wherein, W2: the pulse width used in the next operation T2, W1: the pulse width used in the operation T1,

[0123] K: Gain, DM: Deviation calculated in operation T1

[0124] Therefore, it can be seen that the pulse width W2 is a value that depends on the gain K. The gain K is a value determined based on the deviation amount DM.

[0125] Below, reference Figure 11 , explaining the method of calculating the pulse width W2 using formula (1).

[0126] Figure 11 This is a flowchart of the method for calculating the pulse width W2 in step ST6.

[0127] In step ST61, processor 32 calculates a deviation amount DM which is a difference between the drop amount D calculated in step ST5 and the target change amount TW. Deviation amount DM is expressed by the following equation (2).

[0128] DM=D1-TW(2)

[0129] Where D1: the drop when executing operation T1, TW: the target change

[0130] In this embodiment, the target change amount TW = 0.5 mm. In addition, the drop amount D1 caused by the operation T1 is D1 = 1.0 mm. Therefore, the deviation amount DM is expressed by the following formula (3).

[0131] DM=D1-TW

[0132] =1.0-0.5

[0133] =0.5(mm)(3)

[0134] After the deviation amount DM is calculated, the process proceeds to step ST62.

[0135] In step ST62 , processor 32 determines the value of gain K based on deviation amount DM.

[0136] In this embodiment, the gain K is determined based on the following three conditions (4) to (6).

[0137] DM>0.15:K=0.5(4)

[0138] 0.15≥DM≥-0.05:K=0.8(5)

[0139] -0.05>DM:K=1.8(6)

[0140] That is, the processor 32 determines the gain K to be K = 0.5 when DM>0.15, and determines it to be K = 0.8 when 0.15≥DM≥-0.05. When -0.05>DM, it determines it to be K = 1.8. Here, as shown in formula (3), DM is calculated as DM = 0.5 mm. Therefore, since DM satisfies condition (4), the processor 32 determines the gain K to be K = 0.5. It should be noted that in this embodiment, the gain K is determined based on three conditions, but the gain K can also be determined based on two conditions, or based on four or more conditions. After determining the gain K, the process proceeds to step ST63.

[0141] In step ST63, the pulse width W2 is calculated based on equation (1). Figure 10It can be seen that W1 is W1 = 330ms. In addition, the gain K is determined to be K = 0.5 in step ST62. Furthermore, according to formula (3), the deviation DM is DM = 0.5mm. Therefore, if these values ​​are substituted into formula (1), the pulse width W2 can be calculated as follows.

[0142] W2=W1-W1*K*DM

[0143] =330ms-330ms*0.5*0.5

[0144] =247.5ms(7)

[0145] Therefore, in the operation T1 , the pulse width W1 = 330 ms is used, but through the process of step ST6 , the pulse width W2 corresponding to the next operation T2 is calculated as W2 = 247.5 ms. Figure 10 The calculated pulse width W2 (=247.5 mm) is shown. Once the pulse width W2 is calculated, the process proceeds to step ST7.

[0146] In step ST7, processor 32 determines whether work platform 300 has reached the target height. If work platform 300 has reached the target height, the process ends. On the other hand, if work platform 300 has not reached the target height, the process returns to step ST1. Here, it is assumed that work platform 300 has not reached the target height. Therefore, the process returns to step ST1.

[0147] In step ST1, the processor 32 waits for a tap operation T2 of the down button 13 (refer to Figure 10 ) If the operator 401 performs a tap operation T2 on the down button 13, the process proceeds to step ST2.

[0148] In step ST2, as Figure 6 As shown, an operation signal SB4 for lowering the height of the worktable 300 by a target change amount TW is output from the operation panel 10 and input to the converter 31. Upon receiving the operation signal SB4, the converter 31 converts the voltage of the operation signal SB4 and outputs a signal SB41 after the voltage conversion. Based on the signal SB41 from the converter 31, the processor 32 generates a control signal SC22 having a pulse width W=W2 expressed by equation (7). Figure 10 The pulse width W2 (=247.5 ms) calculated by equation (7) is used as the pulse width W when the tapping operation T2 is performed. After the control signal SC22 including the pulse width W (=W2) is generated, the process proceeds to step ST3.

[0149] In step ST3, the height of the workbench 300 is fine-tuned based on the control signal SC22. Figure 6As shown, control signal SC22 is supplied to buffer 34, and control signal SC221, after undergoing predetermined processing in buffer 34, is supplied to TFT 35. When control signal SC221 is supplied, TFT 35 becomes conductive, and valve 29 opens. At this time, TFT 35 remains conductive only for a time corresponding to pulse width W2 (= 247.5 ms). Consequently, an amount of oil corresponding to pulse width W2 is discharged from cylinder 21 to oil tank 24. Consequently, cylinder 21 moves in the direction of arrow B, lowering object support 303 and finely adjusting the height of worktable 300.

[0150] In step ST4, the current height of the work table 300 corresponding to the operation T2 is displayed on the display unit 16 based on the analog signal SE from the potentiometer 42. When the current height of the work table 300 is displayed, the process proceeds to step ST5.

[0151] In step ST5 , the processor 32 calculates the actual descending amount D of the table 300 based on the digital signal SE received from the ADC 36 . Figure 10 The amount of descent D = D2 of the table 300 corresponding to the operation T2 is shown. Here, D2 = 0.55 mm. After the amount of descent D = D2 (= 0.55 mm) is determined, the process proceeds to step ST6.

[0152] In step ST6, the processor 32 uses the pulse width W2 used in the tapping operation T2 to calculate the pulse width W3 used when lowering the stage in the next tapping operation T3. The pulse width W3 is calculated using the following equation (8).

[0153] W3=W2-W2*K*DM(8)

[0154] Wherein, W3: the pulse width used in the next operation T3, W2: the pulse width used in the operation T2,

[0155] K: Gain, DM: Deviation calculated in operation T2

[0156] It should be noted that when the pulse width W3 is calculated using formula (8), the pulse width W3 is the same as the pulse width W2 and can be calculated as Figure 11 Therefore, refer to Figure 11 , explaining the method of calculating the pulse width W3.

[0157] In step ST61, processor 32 calculates a deviation amount DM which is a difference between the drop amount D calculated in step ST5 and the target change amount TW. Deviation amount DM is expressed by the following equation (9).

[0158] DM=D2-TW(9)

[0159] Where D2: the drop when executing operation T2, TW: the target change

[0160] In this embodiment, the target change amount TW = 0.5 mm. In addition, the drop amount D2 caused by the operation T2 is D2 = 0.55 mm. Therefore, the deviation amount DM is expressed by the following formula (10).

[0161] DM=D2-TW

[0162] =0.55-0.5

[0163] =0.05(mm)(10)

[0164] After the deviation amount DM is calculated, the process proceeds to step ST62.

[0165] In step ST62 , processor 32 determines the value of gain K based on deviation amount DM.

[0166] In this embodiment, as described above, the gain K is determined based on the following three conditions (4) to (6).

[0167] DM>0.15:K=0.5(4)

[0168] 0.15≥DM≥-0.05:K=0.8(5)

[0169] -0.05>DM:K=1.8(6)

[0170] Here, as shown in equation (10), DM is calculated as DM = 0.05 mm. Therefore, since DM satisfies condition (5), processor 32 determines gain K as K = 0.8. After gain K is determined, the process proceeds to step ST63.

[0171] In step ST63, pulse width W3 is calculated according to equation (8). From equation (7), W2 is W2 = 247.5 ms. Furthermore, gain K is determined to be K = 0.8 in step ST62. Furthermore, from equation (10), the deviation DM is DM = 0.05 mm. Therefore, by substituting these values ​​into equation (8), pulse width W3 can be calculated as follows.

[0172] W3=W2-W2*K*DM

[0173] =247.5ms-247.5ms*0.8*0.05

[0174] =237.6ms(11)

[0175] Therefore, in the operation T2, the pulse width W2=247.5 ms is used, but through the process of step ST6, the pulse width W3 corresponding to the next operation T3 is calculated as W3=237.6 ms. Figure 10 The calculated pulse width W3 (=237.6 mm) is shown. Once the pulse width W3 is calculated, the process proceeds to step ST7.

[0176] In step ST7, the processor 32 determines whether the workbench 300 has reached the target height. Here, it is assumed that the workbench 300 has not reached the target height. Therefore, the process returns to step ST1.

[0177] In step ST1, the processor 32 waits for a tap operation T3 of the down button 13 (refer to Figure 10 ) If the operator 401 performs a tapping operation T3 on the down button 13, the process proceeds to step ST2.

[0178] In step ST2, as Figure 6 As shown, an operation signal SB4 for lowering the height of the worktable 300 by a target change amount TW is output from the operation panel 10 and input to the converter 31. Upon receiving the operation signal SB4, the converter 31 converts the voltage of the operation signal SB4 and outputs a signal SB41 after the voltage conversion. Based on the signal SB41 from the converter 31, the processor 32 generates a control signal SC22 having a pulse width W=W3 expressed by equation (11). Figure 10 It is shown that the pulse width W3 (=237.6 ms) is used as the pulse width W when the tapping operation T3 is performed. After the control signal SC22 including the pulse width W (=W3) is generated, the process proceeds to step ST3.

[0179] In step ST3, the height of the workbench 300 is fine-tuned based on the control signal SC22. Figure 6 As shown, control signal SC22 is supplied to buffer 34, and control signal SC221, after undergoing predetermined processing in buffer 34, is supplied to TFT 35. When control signal SC221 is supplied, TFT 35 becomes conductive, and valve 29 opens. At this time, TFT 35 remains conductive only for a time corresponding to pulse width W3 (= 237.6 ms). Consequently, an amount of oil corresponding to pulse width W3 is discharged from cylinder 21 to oil tank 24. Consequently, cylinder 21 moves in the direction of arrow B, lowering object support 303 and finely adjusting the height of worktable 300.

[0180] In step ST4, the current height of the work table 300 corresponding to the operation T3 is displayed on the display unit 16 based on the analog signal SE from the potentiometer 42. When the current height of the work table 300 is displayed, the process proceeds to step ST5.

[0181] In step ST5 , the processor 32 calculates the actual descending amount D of the table 300 based on the digital signal SE received from the ADC 36 . Figure 10 The amount of descent D = D3 of the table 300 corresponding to the operation T3 is shown. Here, D3 = 0.5 mm. After the amount of descent D = D3 (= 0.5 mm) is determined, the process proceeds to step ST6.

[0182] In step ST6, the processor 32 uses the pulse width W3 used in the tapping operation T3 to calculate a pulse width W4 used when lowering the stage in the next tapping operation T4. The pulse width W4 is calculated using the following equation (12).

[0183] W4=W3-W3*K*DM(12)

[0184] Wherein, W4: the pulse width used in the next operation T4, W3: the pulse width used in the operation T3,

[0185] K: Gain, DM: Deviation calculated in operation T3

[0186] It should be noted that when the pulse width W4 is calculated using formula (12), the pulse width W4 is the same as the pulse widths W2 and W3 and can be calculated as Figure 11 Therefore, refer to Figure 11 , explaining the method of calculating the pulse width W4.

[0187] In step ST61, processor 32 calculates a deviation amount DM which is a difference between the drop amount D calculated in step ST5 and the target change amount TW. Deviation amount DM is expressed by the following equation (13).

[0188] DM=D3-TW(13)

[0189] Where D3: the drop when executing operation T3, TW: the target change

[0190] In this embodiment, the target change amount TW = 0.5 mm. In addition, the drop amount D3 caused by the operation T3 is D3 = 0.5 mm. Therefore, the deviation amount DM is expressed by the following formula (14).

[0191] DM=D3-TW

[0192] =0.5-0.5

[0193] =0(mm)(14)

[0194] After the deviation amount DM is calculated, the process proceeds to step ST62.

[0195] In step ST62 , processor 32 determines the value of gain K based on deviation amount DM.

[0196] In this embodiment, as described above, the gain K is determined based on the following three conditions (4) to (6).

[0197] DM>0.15:K=0.5(4)

[0198] 0.15≥DM≥-0.05:K=0.8(5)

[0199] -0.05>DM:K=1.8(6)

[0200] Here, as shown in equation (14), DM is calculated as DM = 0 mm. Therefore, since DM satisfies condition (5), processor 32 determines gain K as K = 0.8. After gain K is determined, the process proceeds to step ST63.

[0201] In step ST63, pulse width W4 is calculated based on equation (12). From equation (11), W3 is W3 = 237.6 ms. Furthermore, gain K is set to K = 0.8 in step ST62. Furthermore, from equation (14), the deviation DM is DM = 0 mm. Therefore, by substituting these values ​​into equation (12), pulse width W4 can be calculated as follows.

[0202] W4=W3-W3*K*DM

[0203] =237.6ms-237.6ms*0.8*0

[0204] =237.6ms(15)

[0205] Therefore, the pulse width W4 corresponding to the next operation T4 is calculated as W4=237.6 ms. Figure 10 The calculated pulse width W4 (=237.6 mm) is shown. Once the pulse width W4 is calculated, the process proceeds to step ST7.

[0206] In step ST7, the processor 32 determines whether the workbench 300 has reached the target height. Here, it is assumed that the workbench 300 has not reached the target height. Therefore, the process returns to step ST1.

[0207] In step ST1, the processor 32 waits for a tap operation T4 of the down button 13 (refer to Figure 10 ) If the operator 401 performs a tapping operation T4 on the down button 13, the process proceeds to step ST2.

[0208] In step ST2, as Figure 6As shown, an operation signal SB4 for lowering the height of the worktable 300 by a target change amount TW is output from the operation panel 10 and input to the converter 31. Upon receiving the operation signal SB4, the converter 31 converts the voltage of the operation signal SB4 and outputs a signal SB41 after the voltage conversion. Based on the signal SB41 from the converter 31, the processor 32 generates a control signal SC22 having a pulse width W=W4 expressed by equation (15). Figure 10 It is shown that a pulse width W4 (=237.6 ms) is used as the pulse width W when the tapping operation T4 is performed. After the control signal SC22 including the pulse width W (=W4) is generated, the process proceeds to step ST3.

[0209] In step ST3, the height of the workbench 300 is fine-tuned based on the control signal SC22. Figure 6 As shown, control signal SC22 is supplied to buffer 34, and control signal SC221, after undergoing predetermined processing in buffer 34, is supplied to TFT 35. When control signal SC221 is supplied, TFT 35 becomes conductive, and valve 29 opens. At this time, TFT 35 remains conductive only for a time corresponding to pulse width W4 (= 237.6 ms). Consequently, an amount of oil corresponding to pulse width W2 is discharged from cylinder 21 to oil tank 24. Consequently, cylinder 21 moves in the direction of arrow B, lowering object support 303 and finely adjusting the height of worktable 300.

[0210] In step ST4, the current height of the work table 300 corresponding to the operation T4 is displayed on the display unit 16 based on the analog signal SE from the potentiometer 42. When the current height of the work table 300 is displayed, the process proceeds to step ST5.

[0211] In step ST5 , the processor 32 calculates the actual lowering amount D of the table 300 based on the digital signal SE received from the ADC 36 . Figure 10 The amount of descent D = D4 of the table 300 corresponding to the operation T3 is shown. Here, D4 ​​= 0.5 mm. After the amount of descent D = D4 (= 0.5 mm) is determined, the process proceeds to step ST6.

[0212] In step ST6, the processor 32 uses the pulse width W4 used in the tapping operation T4 to calculate the pulse width W5 used when lowering the stage in the next tapping operation T5. The pulse width W5 is calculated using the following formula (16).

[0213] W5=W4-W4*K*DM(16)

[0214] Wherein, W5: the pulse width used in the next operation T5, W4: the pulse width used in the operation T4,

[0215] K: Gain, DM: Deviation calculated in operation T4

[0216] It should be noted that when the pulse width W5 is calculated using formula (16), the pulse width W5 is the same as the pulse widths W2 to W4 and can be calculated according to Figure 11 Therefore, refer to Figure 11 , explaining the method of calculating the pulse width W5.

[0217] In step ST61, the processor 32 calculates a deviation amount DM which is a difference between the drop amount D calculated in step ST5 and the target change amount TW. The deviation amount DM is expressed by the following equation (17).

[0218] DM=D4-TW(17)

[0219] Where D4: the drop when executing operation T4, TW: the target change

[0220] In this embodiment, the target change amount TW = 0.5 mm. In addition, the drop amount D4 caused by the operation T4 is D4 = 0.5 mm. Therefore, the deviation amount DM is expressed by the following formula (18).

[0221] DM=D4-TW

[0222] =0.5-0.5

[0223] =0(mm)(18)

[0224] After the deviation amount DM is calculated, the process proceeds to step ST62.

[0225] In step ST62 , processor 32 determines the value of gain K based on deviation amount DM.

[0226] In this embodiment, as described above, the gain K is determined based on the following three conditions (4) to (6).

[0227] DM>0.15:K=0.5(4)

[0228] 0.15≥DM≥-0.05:K=0.8(5)

[0229] -0.05>DM:K=1.8(6)

[0230] Here, as shown in equation (18), DM is calculated as DM = 0 mm. Therefore, since DM satisfies condition (5), processor 32 determines gain K as K = 0.8. After gain K is determined, the process proceeds to step ST63.

[0231] In step ST63, pulse width W5 is calculated based on equation (16). From equation (15), W4 is W4 = 237.6 ms. Furthermore, gain K is set to K = 0.8 in step ST62. Furthermore, from equation (18), the deviation DM is DM = 0 mm. Therefore, by substituting these values ​​into equation (16), pulse width W5 can be calculated as follows.

[0232] W5=W4-W4*K*DM

[0233] =237.6ms-237.6ms*0.8*0

[0234] =237.6ms(19)

[0235] Therefore, the pulse width W5 corresponding to the next operation T5 is calculated as W5 = 237.6 ms.

[0236] Likewise, each time a tapping operation is performed to lower the height of the workbench 300, the pulse width used in the next tapping operation is calculated. In the above description, the example of calculating the pulse widths W2, W3, W4, and W5 is described. However, if the calculated pulse width is expressed as "W i+1 " indicates that the pulse width W i+1 It can be calculated using the following formula (20).

[0237] W i+1 =W i -W i *K*DM(20)

[0238] Among them, W i+1 :In the next operation T i+1 The pulse width used in i :In operation T i The pulse width used in

[0239] K: gain, DM: in operation T i The deviation calculated in

[0240] For example, after executing operation T p In the case of the next operation T p+1 The pulse width W used in p+1 The calculation is performed by substituting i=p into i in formula (20) to obtain the following formula.

[0241] W p+1 =W p -W p *K*DM(21)

[0242] Among them, W p+1 :In the next operation T p+1The pulse width used in p :In operation T p The pulse width used in

[0243] K: gain, DM: in operation T p The deviation calculated in

[0244] Therefore, each time the operation is performed, the pulse width W used to make the descending amount of the workbench consistent with the target change amount (or close to the target change amount) can be calculated based on formula (20): i+1 Then, in step ST7, if it is determined that the workbench 300 has reached the target height, the process ends.

[0245] In the present embodiment, when the height of the workbench 300 is fine-tuned, the operator 401 uses the buttons of the operation panel 10 to perform the fine-tuning operation of the workbench 300. When the operator 401 performs the fine-tuning operation for lowering the height of the workbench 300 by the target change amount, fine-tuning is performed according to the operation of the operator 401 to lower the height of the workbench 300. On the other hand, the processor 32 adjusts the pulse width based on the deviation DM between the actual descent amount D of the workbench 300 and the target change amount TW. In the present embodiment, the value of the gain K is determined according to the value of the deviation DM, so that the pulse width for making the deviation DM 0 (or reducing) can be calculated. Then, when the operator 401 performs the next operation, the height of the workbench 300 is fine-tuned based on the calculated pulse width. Therefore, even if the amount D of descent of the worktable 300 differs from the target change TW when fine-tuning the height of the worktable 300, the pulse width can be calculated based on the deviation DM as described above, allowing the amount D of descent of the worktable 300 to approach the target change TW, ultimately aligning the amount D with the target change TW. Once the amount D of descent is aligned with the target change TW, the amount D stabilizes, and the amount D of descent of the worktable 300 can then be (substantially) aligned with the target change TW. Therefore, the actual amount D of descent is stabilized relative to the operator 401's operation, reducing the workload on the operator 401 involved in adjusting the height of the worktable 300.

[0246] In this embodiment, Figure 9 In the process, the value of gain K is determined according to the deviation DM and the pulse width is calculated (refer to step ST), but for reference, Figure 12 The flow when the pulse width is set to a fixed value is shown in . Figure 12 In the process of FIG, since the pulse width is a fixed value, there is no step ST5 for calculating the drop amount and step ST6 for calculating the pulse width. Therefore, the pulse width cannot be set to the optimal value. As a result, Figure 8As shown, the amount of descent of the worktable cannot be made consistent with the target change amount. In contrast, in this embodiment, due to the presence of steps ST5 and ST6, even if the amount of descent of the worktable does not correspond to the target change amount, the amount of descent of the worktable 300 can be quickly (substantially) made consistent with the target change amount TW by determining the value of gain K based on the deviation amount DM and calculating the pulse width.

[0247] It should be noted that, in order to clarify the effect of this embodiment, the relationship between the number of tapping operations and the amount of movement of the height of the workbench is calculated. Figure 13 shown.

[0248] exist Figure 13 , there are shown graphs 91, 92, and 93. Graphs 91 to 93 show the relationship between the number of tapping operations and the amount of movement of the worktable height when the initial value of the amount of movement of the worktable is 0.2 (mm), 0.3 (mm), 0.4 (mm), 0.5 (mm), 0.6 (mm), 0.7 (mm), 0.8 (mm), 0.9 (mm), and 1.0 (mm).

[0249] Graph 91 shows the relationship between the number of tapping operations and the amount of movement of the table height when the pulse width is set to a fixed value. It can be seen that when the pulse width is set to a fixed value, the amount of movement does not change from the initial value even if the tapping operation is repeated several times.

[0250] Graph 92 shows the relationship between the number of tapping operations and the amount of table height movement when proportional control is used with a fixed gain K. With proportional control using a fixed gain K, repeated tapping operations converge the movement from the initial value to the target movement of 0.5 mm. However, four to five repeated tapping operations are required for convergence.

[0251] Graph 93 shows the relationship between the number of tapping operations and the amount of movement of the table height when the method of this embodiment is used, which determines the gain K based on the deviation DM. It can be seen that when the method of this embodiment is used, the movement amount converges from the initial value to the target movement amount of 0.5 mm by repeating the tapping operation three times.

[0252] Therefore, as can be seen from Graphs 91 to 93 , by adopting the method of this embodiment, even when the descent amount of the worktable does not coincide with the target change amount, the descent amount of the worktable 300 quickly (substantially) coincides with the target change amount TW.

[0253] It should be noted that Figure 10 The operation T1 to Tp of finely adjusting the height of the workbench 300 to lower the workbench 300 by the amount D is shown.+1 However, it is also possible to operate T1 to T p+1 Perform other operations to adjust the workbench height (see Figure 14 ).

[0254] Figure 14 This is a diagram showing an example in which another operation of adjusting the height of the table is performed between operations T1 to T5.

[0255] exist Figure 14 , it is shown that the operation U11 is executed between the operation T1 and the operation T2 to continuously lower the workbench 300, and the operation U11 is executed between the operation T3 and the operation T4 to raise the workbench 300 by the target change amount TV (reference Figure 3 ) operation example U12.

[0256] In this manner, even if other operations U11 and U12 are executed between operations T1 to T5, only operations T1 to T5 are focused on, and the deviation DM is calculated for each of these operations in the order described above. The value of the gain K is determined based on the deviation DM, thereby enabling the calculation of pulse widths W2 to W5. Consequently, the decrease D can be quickly brought into alignment with the target change TW.

[0257] It should be noted that, in the first embodiment, the lowering amount D of the table 300 is adjusted to the target change amount TW (reference Figure 4 ) is consistent with the example described above, but the present invention can also be applied to make the lifting amount of the workbench 300 consistent with the target change amount TV (reference Figure 3 When the workbench 300 is raised, the deviation DM between the amount of rise of the workbench and the target change amount TV is calculated, and the value of the gain K is determined based on the deviation DM. This allows calculation of the pulse width for making the amount of rise of the workbench consistent with (or close to) the target change amount TV.

[0258] (2) (Second embodiment)

[0259] In the second embodiment, a case where the CT system has a function of adjusting the tilt angle of the gantry 200 will be described.

[0260] Figure 15 1 is a block diagram of the gantry 200 and the gantry control device 600 that controls the tilt angle of the main body of the gantry.

[0261] It should be noted that the gantry control device 600 of the second embodiment is basically the same as the stage control device 500 described in the first embodiment. Therefore, in the description of the second embodiment, the differences from the first embodiment will be mainly described.

[0262] The scanning gantry control device 600 includes a hydraulic device 20. The hydraulic device 20 includes a unit 23 of a cylinder 21 and a piston 22, an oil tank 24, a supply pipe 25, a discharge pipe 26, and an oil quantity adjustment unit 27. The hydraulic device 20 is housed inside the scanning gantry 200, but is not Figure 15 In the figure, components other than unit 23 are shown outside of gantry 200 to facilitate visualization of the components of the hydraulic system 20. When the cylinder 21 moves in the direction of arrow B toward the piston 22, gantry 200 tilts toward the rear side 52 about the rotation axis 57. On the other hand, when the cylinder 21 moves in the direction of arrow A relative to the piston 22, gantry 200 tilts toward the front side 51 about the rotation axis 57. It should be noted that the configuration of unit 23, oil tank 24, supply pipe 25, discharge pipe 26, and oil quantity adjustment unit 27 of the hydraulic system 20 is identical to that of the hydraulic system described in the first embodiment, and therefore, any overlapping descriptions of the first embodiment will be omitted.

[0263] The gantry control device 600 includes an operation panel 10 and a control board 330. The operation panel 10 has the same structure as the operation panel 10 described in the first embodiment. The control board 330 of the second embodiment includes a relay 43 that supplies an AC signal from an AC source 41 to the pump 28. The remaining structure is the same as that of the control board 30 of the first embodiment.

[0264] Figure 16 It is an explanatory diagram of the operation panel 10 in the second embodiment.

[0265] exist Figure 16 In the description, only the parts related to the operation of the CT system of the second embodiment are denoted by reference numerals.

[0266] The operation panel 10 includes a front tilt button 14 and a rear tilt button 15 for tilting the gantry 200 . The front tilt button 14 tilts the gantry 200 toward the front side 51 , and the rear tilt button 15 tilts the gantry 200 toward the rear side 52 .

[0267] To coarsely adjust the tilt angle of the gantry 200, the operator 401 presses and holds the forward tilt button 14 or the backward tilt button 15. For example, to continuously tilt the gantry 200 toward the front side 51, the operator 401 presses and holds the forward tilt button 14. While the operator 401 is pressing and holding the forward tilt button 14, the gantry 200 continuously tilts toward the front side 51. On the other hand, to continuously tilt the gantry 200 toward the rear side 52, the operator 401 presses and holds the backward tilt button 15. While the operator 401 is pressing and holding the backward tilt button 15, the gantry 200 continuously tilts toward the rear side 52.

[0268] Furthermore, when the operator 401 wants to finely adjust the tilt angle of the gantry 200 , the operator 401 performs a tapping operation by pressing the forward tilt button 14 or the backward tilt button 15 and then immediately releasing the hand from the button 14 or 15 . Figure 17 This is an explanatory diagram of the tapping operation on the front tilt button 14. Figure 17 In FIG, the scanning frame 200 before the tapping operation is indicated by a dotted line, and the scanning frame 200 after the tapping operation is indicated by a solid line. The tilt angle of the scanning frame 200 changes from the tilt angle 53 to the tilt angle 54 by a single tapping operation. That is, the scanning frame 200 is set so that the tilt angle changes by the target change amount TA toward the front side 51 by a single tapping operation. Figure 17 In the figure, the target change amount TA is exaggerated to make it easier to understand. However, in reality, the target change amount TA is approximately TA = 0.1 (degrees) to 0.5 (degrees). Therefore, the operator 401 can finely control the tilt angle of the gantry 200 by tapping the forward tilt button 14.

[0269] on the other hand, Figure 18 This is an explanatory diagram of the tapping operation on the rear tilt button 15. Figure 18 In FIG, the scanning frame 200 before the tapping operation is indicated by a dotted line, and the scanning frame 200 after the tapping operation is indicated by a solid line. The tilt angle of the scanning frame 200 changes from the tilt angle 55 to the tilt angle 56 by a single tapping operation. That is, the scanning frame 200 is set so that the tilt angle changes by the target change amount TB toward the back side 52 by a single tapping operation. Figure 18 In the figure, the target change amount TB is exaggerated to make it easier to understand. However, in reality, the target change amount TB is approximately TB = 0.1 (degrees) to 0.5 (degrees). Therefore, the operator 401 can finely control the tilt angle of the gantry 200 by tapping the rear tilt button 15.

[0270] Note that the target change amount TA when the gantry 200 is tilted toward the front side 51 is the same as the target change amount TB when the gantry 200 is tilted toward the back side 52 (ie, TA=TB). However, TA≠TB may be used.

[0271] return Figure 16 Continue with the description.

[0272] The display unit 16 of the operation panel 10 includes a display area 18. The display area 18 is an area for displaying the current tilt angle of the gantry.

[0273] Therefore, the operator 401 can adjust the tilt angle of the gantry 200 while checking the current tilt angle of the gantry 200 on the display unit 16 by tapping the forward tilt button 14 or the backward tilt button 15 .

[0274] Furthermore, the gantry control device 600 includes a potentiometer 42 . The potentiometer 42 measures the tilt angle of the gantry 200 .

[0275] The gantry control device 600 is configured as described above. When the operator 401 fine-tunes the tilt angle of the gantry 200, ideally, the tilt angle of the gantry 200 changes by a target change amount TA or TB (e.g., 0.5 degrees). However, depending on the operating environment of the gantry 200 (e.g., the temperature and humidity of the scanning room), the actual change amount of the tilt angle of the gantry 200 may deviate from the target change amount TA or TB.

[0276] Thus, even when the gantry tilt angle does not match the target variation TA or TB, as described in the first embodiment, the gain K is adjusted based on the deviation DM to calculate a pulse width that can make the deviation DM 0 (or close to 0).

[0277] It should be noted that, in the first and second embodiments, a CT system is used as an example of a medical device. However, the present invention is not limited to CT systems and can be applied to medical devices that require the use of cylinders and pistons to adjust the movement of movable bodies (e.g., MRI devices, PET-CT devices, PET-MRI devices, and radiotherapy devices).

[0278] Description of Reference Numerals

[0279] 10: Operation panel

[0280] 11: Button

[0281] 12: Up button

[0282] 13: Down button

[0283] 14: Front tilt button

[0284] 15: Rear tilt button

[0285] 16: Display unit

[0286] 17: Display area

[0287] 18: Display area

[0288] 20: Hydraulic device

[0289] 21: Cylinder

[0290] 22: Pistons

[0291] 23: Unit

[0292] 24: Fuel tank

[0293] 25: Supply pipe

[0294] 26: Discharge pipe

[0295] 27: Oil quantity adjustment unit

[0296] 28: Pump

[0297] 29: Valve

[0298] 30: Control Panel

[0299] 31: Converter

[0300] 32: Processor

[0301] 33: Buffer

[0302] 34: Buffer

[0303] 35: TFT

[0304] 36: ADC

[0305] 37: Storage device

[0306] 40: Inverter

[0307] 41: AC source

[0308] 42: Potentiometer

[0309] 43: Relay

[0310] 51: front side

[0311] 52: Back side

[0312] 53~56: Tilt angle

[0313] 57: Rotation axis

[0314] 91-93: Chart

[0315] 100: CT system

[0316] 200: Scanning rack

[0317] 201: Hole

[0318] 300: Workbench

[0319] 301: Base

[0320] 302: Legs

[0321] 303: Subject support

[0322] 330: Control Panel

[0323] 400: Subject

[0324] 401: Operator

[0325] 500: Workbench control device

[0326] 600: Scanner control device

Claims

1. A movable body control device, comprising: A unit comprising a cylinder and a piston, wherein at least a portion of the piston is disposed within the cylinder, and the cylinder and the piston are moved relative to each other by adjusting the amount of working fluid within the cylinder; a movable body that moves according to the relative movement of the cylinder and the piston; a control unit that generates, based on a first operation signal input by a user operation for moving the movable body by a target change amount, a control signal including a first pulse width corresponding to the target change amount, so as to move the movable body by the target change amount; a fluid amount adjustment unit that adjusts the amount of working fluid contained in the cylinder based on the first pulse width, and The control unit performs: By adjusting the amount of the working fluid in the cylinder, the movement amount of the movable body is determined; determining a gain value based on an amount of deviation between the amount of movement of the movable body and the target amount of change; calculating a second pulse width based on the offset and the determined gain value; When a second operation signal for moving the movable body by a target change amount is input after the first operation signal, a control signal including the second pulse width is generated, and The fluid amount adjustment unit adjusts the amount of the working fluid in the cylinder based on the second pulse width.

2. The movable body control device according to claim 1, wherein: The control unit The value of the gain is determined based on which of a plurality of conditions the deviation satisfies.

3. The movable body control device according to claim 2, wherein: The control unit The value of the gain is determined based on which of three conditions the deviation satisfies.

4. The movable body control device according to claim 3, wherein: The control unit When the deviation satisfies the first of the three conditions, the gain value is determined to be a first value; when the deviation satisfies the second of the three conditions, the gain value is determined to be a second value; and when the deviation satisfies the third of the three conditions, the gain value is determined to be a third value.

5. The movable body control device according to claim 1, wherein: The movable body control device is used for a working table of a medical device. The movable body is a subject supporting portion of the table, The first operation signal and the second operation signal are operation signals for changing the height of the table by the target change amount.

6. The movable body control device according to claim 5, wherein: The target change amount is a target change amount when the table is lowered.

7. The movable body control device according to claim 5, wherein: The target change amount is a target change amount when the table is raised.

8. The movable body control device according to claim 1, wherein: The movable body control device is used for a scanning frame of a medical device. The movable body is the scanning frame, The first operation signal and the second operation signal are operation signals for changing the tilt angle of the gantry by the target change amount.

9. The movable body control device according to claim 8, wherein: The target change amount is a target change amount when the gantry is tilted toward the front side of the gantry.

10. The movable body control device according to claim 8, wherein: The target change amount is a target change amount when the gantry is tilted toward the back side of the gantry.

11. The movable body control device according to claim 1, wherein: The fluid volume adjustment unit includes: a pump that supplies the working fluid to the cylinder; and A valve discharges the working fluid from the cylinder.

12. The movable body control device according to claim 11, wherein: The pump supplies the working fluid in an amount corresponding to the second pulse width to the cylinder.

13. The movable body control device according to claim 11, wherein: The valve supplies the working fluid in an amount corresponding to the second pulse width from the cylinder.

14. The movable body control device according to claim 1, wherein: The movable body control device includes a potentiometer that outputs an analog signal representing a voltage corresponding to the movement of the movable body. The control unit includes an ADC that converts the analog signal from the potentiometer into a digital signal. The control unit calculates a movement amount of the movable body based on the digital signal from the ADC.

15. The movable body control device according to claim 1, wherein: The control unit performs: determining a gain value based on a deviation between the movement amount of the movable body and the target change amount each time an operation signal for moving the movable body by a target change amount is input; Based on the offset amount and the determined gain value, a pulse width used when the next operation signal is input is calculated.

16. A non-transitory computer-readable storage medium, which is included in a movable body control device or is capable of communicating with a movable body control device, The movable body control device includes: A unit comprising a cylinder and a piston, wherein at least a portion of the piston is disposed within the cylinder, and the cylinder and the piston are moved relative to each other by adjusting the amount of working fluid within the cylinder; a movable body that moves according to the relative movement of the cylinder and the piston; a control unit that generates, based on a first operation signal input by a user operation for moving the movable body by a target change amount, a control signal including a first pulse width corresponding to the target change amount, so as to move the movable body by the target change amount; a fluid amount adjustment unit that adjusts the amount of working fluid contained in the cylinder based on the first pulse width, and The control unit includes one or more processors, The instructions contained in the storage device, when executed by the one or more processors, cause the one or more processors to perform: By adjusting the amount of the working fluid in the cylinder, the movement amount of the movable body is determined; determining a gain value based on an amount of deviation between the amount of movement of the movable body and the target amount of change; calculating a second pulse width based on the offset and the determined gain value; When a second operation signal for moving the movable body by a target change amount is input after the first operation signal, a control signal including the second pulse width is generated, and The fluid amount adjustment unit adjusts the amount of the working fluid in the cylinder based on the second pulse width.

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