Motor drive device

Abstract

A motor drive device drives a motor for controlling a position of an object based on an instruction from a controller, the motor drive device including a correction instruction output section that outputs a correction instruction for correcting a position of the motor based on a position of the object detected by a displacement sensor for detecting the position of the object, and a position control section that outputs a drive signal for driving the motor based on an instruction from the controller and a position of the motor detected by an encoder for detecting the position of the motor, or based on the correction instruction and the position of the motor detected by the encoder.

Description

TECHNICAL FIELD

[0001] The present disclosure relates to a motor drive device that drives a motor. BACKGROUND

[0002] Conventionally, a motor drive device that drives a motor for controlling a position of an object based on an instruction from a controller is known.

[0003] For example, a motor drive device that drives a motor based on a correction target position instruction obtained by feedback of a sensing result of a sensor for detecting a position of an object output from a controller is described in Patent Literature 1.

[0004] According to the technology described in Patent Literature 1, feedback of a sensing result is transmitted to the motor drive device via the controller. Therefore, a time lag is sometimes generated between a timing of sensing by the sensor and a timing at which feedback is transmitted to the motor drive device. The control accuracy of the position of the object is sometimes reduced due to the time lag.

[0005] PRIOR ART DOCUMENTS

[0006] PATENT LITERATURE

[0007] Patent Literature 1: Japanese Patent Application Publication No. 2008-299710 SUMMARY

[0008] Therefore, an object of the present disclosure is to provide a motor drive device that can suppress reduction in control accuracy of a position of an object.

[0009] A motor drive device according to one embodiment of the present disclosure drives a motor for controlling a position of an object based on an instruction from a controller, the motor drive device including: a correction instruction output section that outputs a correction instruction for correcting a position of the motor based on a position of the object detected by a displacement sensor for detecting the position of the object; and a position control section that outputs a drive signal for driving the motor based on the instruction from the controller and a position of the motor detected by an encoder for detecting the position of the motor, or based on the correction instruction and the position of the motor detected by the encoder.

[0010] Thus, a motor drive device that can suppress reduction in control accuracy of a position of an object is provided. BRIEF DESCRIPTION OF DRAWINGS

[0011] Figure 1 is a schematic view showing a structure of a sheet winding system according to an embodiment.

[0012] Figure 2is a graph showing a relationship between a position of an object detected by the displacement sensor and a voltage in a position signal output from the displacement sensor.

[0013] Figure 3 is a block diagram showing a configuration example of the position correction mechanism and the motor drive device according to the embodiment.

[0014] Figure 4 is a graph showing a relationship between a position signal before saturation processing input to the saturation processing section and a position signal after saturation processing output from the saturation processing section.

[0015] Figure 5 is a graph showing a relationship between a correction amount of a position of an object and a voltage in a correction signal output from the controller.

[0016] Figure 6 is a graph showing a relationship between a correction signal before saturation processing input to the saturation processing section and a correction signal after saturation processing output from the saturation processing section.

[0017] Figure 7 is a graph showing a case where the absolute value of the first saturation voltage and the absolute value of the second saturation voltage are changed in a manner increasing with time by the saturation processing section.

[0018] Figure 8 is a flowchart of the first operation state change processing.

[0019] Figure 9 is a flowchart of the second operation state change processing.

[0020] Figure 10 is a flowchart of the third operation state change processing.

[0021] Figure 11 is a flowchart of the fourth operation state change processing.

[0022] Figure 12 is a flowchart of the fifth operation state change processing. DETAILED DESCRIPTION

[0023] (Process of achieving one embodiment of the present disclosure)

[0024] As described above, according to the technology described in Patent Literature 1, sometimes the control accuracy of the position of the object decreases due to a time lag occurring between the timing of sensing by the sensor and the timing at which feedback is delivered to the motor drive device. Therefore, the inventors considered that it is possible to suppress the decrease in the control accuracy of the position of the object by suppressing the time lag. The inventors intensively and repeatedly conducted experiments and researches on a motor drive device capable of suppressing the time lag. As a result, the inventors conceived the following motor drive device.

[0025] The motor drive device according to one embodiment of the present disclosure drives a motor for controlling a position of an object based on an instruction from a controller, and includes a correction instruction output section that outputs a correction instruction for correcting a position of the motor based on a position of the object detected by a displacement sensor for detecting the position of the object, and a position control section that outputs a drive signal for driving the motor based on the instruction from the controller and a position of the motor detected by an encoder for detecting the position of the motor, or based on the correction instruction and the position of the motor detected by the encoder.

[0026] According to the motor drive device described above, the position of the object detected by the displacement sensor can be fed back to the drive signal without passing through the controller. Therefore, according to the motor drive device described above, the time lag described above is suppressed. Thus, according to the motor drive device described above, the control accuracy of the position of the object can be suppressed from decreasing.

[0027] In addition, the motor drive device can further include a switching section that selectively outputs the correction instruction and the instruction from the controller, and the position control section can output the drive signal based on the instruction from the controller or the correction instruction selectively output from the switching section and the position of the motor detected by the encoder.

[0028] Thus, interference between the instruction from the controller and the correction instruction can be suppressed.

[0029] In addition, the switching section can switch to the second state after a predetermined period elapses after the switching signal is input when the switching section is in the first state in which the instruction from the controller is selectively output.

[0030] Thus, for example, the switching section can be switched from the first state to the second state after a period in which the operation of the displacement sensor is unstable, such as a period in which the displacement sensor is waited for to elapse after being started.

[0031] In addition, the switching section can switch to the second state after the position of the object detected by the displacement sensor becomes within the predetermined range if the position of the object detected by the displacement sensor is not within the predetermined range when the switching section is input with the switching signal indicating a switch from the first state in which the instruction from the controller is selectively output to the second state in which the correction instruction is selectively output.

[0032] Thus, in a case where the position of the object detected by the displacement sensor becomes within the prescribed range, the switching section automatically switches from the first state to the second state. Therefore, it is possible to suppress a decrease in control accuracy of the position of the object due to the switching section not switching from the first state to the second state in a case where the position of the object detected by the displacement sensor becomes within the prescribed range.

[0033] Further, it can be configured that, when a switching signal indicating a desire to switch from the first state to the second state in which the corrected command is selectively output is input while being in the first state in which the command from the controller is selectively output, the switching section switches to the second state if the position of the object detected by the displacement sensor becomes within the prescribed range for a prescribed period.

[0034] Thus, in a case where a phenomenon in which the signal indicating the position of the object detected by the displacement sensor momentarily varies, such as a phenomenon in which a spike-shaped noise is superimposed, occurs, it is possible to suppress a malfunction of the motor drive device due to the phenomenon.

[0035] Further, it can be configured that, when a switching signal indicating a desire to switch from the first state to the second state in which the corrected command is selectively output is input while being in the first state in which the command from the controller is selectively output, the switching section switches to the second state if, at a timing at which a prescribed period has elapsed from when the switching signal is input, the position of the object detected by the displacement sensor is not within the prescribed range, after the position of the object detected by the displacement sensor becomes within the prescribed range.

[0036] Thus, in a case where the position of the object detected by the displacement sensor becomes within the prescribed range after a prescribed period has elapsed, the switching section automatically switches from the first state to the second state. Therefore, it is possible to suppress a decrease in control accuracy of the position of the object due to the switching section not switching from the first state to the second state in a case where the position of the object detected by the displacement sensor becomes within the prescribed range after a prescribed period has elapsed.

[0037] Further, it can be configured that, when a switching signal indicating a desire to switch from the first state to the second state in which the corrected command is selectively output is input while being in the first state in which the command from the controller is selectively output, the switching section switches to the second state if, after a first prescribed period has elapsed from when the switching signal is input, the position of the object detected by the displacement sensor is within the prescribed range for a second prescribed period.

[0038] Thus, in a case where a phenomenon in which the signal instantaneously varies, a phenomenon in which noise such as a superimposed spike occurs, or the like occurs, which is indicative of the position detected by the displacement sensor, after the first prescribed period elapses, the erroneous operation of the motor drive device due to the phenomenon can be suppressed.

[0039] In addition, the motor drive device can further include a saturation processing section that performs saturation processing on the position of the object detected by the displacement sensor, and the correction instruction output section can output the correction instruction based on the position that has been subjected to the saturation processing.

[0040] Thus, the occurrence of an adverse situation due to the motor being sharply driven can be suppressed.

[0041] In addition, the saturation processing section can change the absolute value of the saturation value in the saturation processing in such a manner that the absolute value increases with time, in a case where a switching signal that indicates a desire for the switching section to switch from the first state in which the instruction is selectively output to the second state in which the correction instruction is selectively output is input.

[0042] Thus, the occurrence of an adverse situation due to the motor being sharply driven due to the switching section being switched from the first state to the second state can be suppressed.

[0043] Hereinafter, a specific example of a motor control device according to an embodiment of the present disclosure will be described with reference to the drawings. The embodiments shown herein each represent one specific example of the present disclosure. Thus, the numerical values, shapes, structural elements, arrangement and connection modes of structural elements, and steps (procedures) and orders of steps shown in the following embodiments are merely examples, and are not intended to limit the present disclosure. In addition, each drawing is a schematic view, and is not necessarily strictly illustrated.

[0044] Further, the inclusive or specific modes of the present disclosure can be implemented by a system, a method, an integrated circuit, a computer program, or a recording medium such as a CD-ROM (Compact Disc Read only memory) that is readable by a computer, and can be implemented by any combination of a system, a method, an integrated circuit, a computer program, and a recording medium.

[0045] (Embodiment)

[0046] <Structure>

[0047] Figure 1 is a schematic view showing the structure of a sheet winding system 1 according to an embodiment.

[0048] As Figure 1As shown, the sheet winding system 1 is configured to include a motor drive device 10, a controller 20, a position correction mechanism 30, a displacement sensor 40, a winder 50, an object 60 (here, the sheet 60), and an input device 70.

[0049] The winder 50 winds the object 60, i.e., the sheet 60. Here, the winder 50 winds the sheet 60 along its long side (…). Figure 1 The winding along the x-axis direction (as shown in the diagram).

[0050] Displacement sensor 40 detects the position of object 60. Here, displacement sensor 40 detects the position of sheet 60 in the short side direction (…). Figure 1 The position on the y-axis (as shown in the diagram). More specifically, the displacement sensor 40 is a sensor (laser displacement sensor) that illuminates the sheet 60 with a laser. Figure 1 Near the end portion in the y-axis direction shown, at least one of the reflected light from the laser reflected by the sheet 60 and the laser light not reflected by the sheet 60 is received, thereby detecting the sheet 60. Figure 1 The position of the terminal part in the y-axis direction is shown.

[0051] When the displacement sensor 40 detects the position of the object 60, it outputs a position signal indicating the detected position.

[0052] Figure 2 It is a graph showing the relationship between the position of the object 60 detected by the displacement sensor 40 and the voltage in the position signal output from the displacement sensor 40.

[0053] exist Figure 2 In the diagram, the horizontal axis represents the difference Δy1 between the position of the object 60 detected by the displacement sensor 40 and the reference position, and the vertical axis represents the voltage of the position signal.

[0054] like Figure 2 As shown, the displacement sensor 40 outputs a position signal as a voltage, which is proportional to the difference Δy1 between the position of the object 60 detected by the displacement sensor 40 and the reference position.

[0055] Return to Figure 1 Continuing with the description of the sheet winding system 1.

[0056] The position correction mechanism 30 includes a motor for controlling the position of the object 60. Here, the position correction mechanism 30 controls the sheet 60 in... Figure 1 The position along the y-axis is shown.

[0057] As the winder 50 winds the sheet 60, the sheet 60... Figure 1The position in the y-axis direction shown in FIG. 1 can sometimes deviate from the desired reference position. Such a deviation occurs, for example, in the case where the thickness of the sheet 60 is not uniform, in the case where a roller constituting the winder 50 is worn, and so on.

[0058] The position correction mechanism 30 is a mechanism for correcting such a deviation to return the position of the sheet 60 in the y-axis direction shown in FIG. 1 to the desired reference position. Figure 1

[0059] The motor drive device 10 drives the motor included in the position correction mechanism 30 based on the position command from the controller 20.

[0060] Figure 3 is a block diagram showing a configuration example of the position correction mechanism 30 and the motor drive device 10 involved in the embodiment.

[0061] As shown in FIG. 3, the position correction mechanism 30 is provided with a motor 31 and an encoder 32. Figure 3

[0062] The motor 31 controls the position of the object 60. Here, the motor 31 controls the position of the sheet 60 in the y-axis direction shown in FIG. 1. The motor 31 is driven in accordance with a drive signal (described later) output from the motor drive device 10. The motor 31 can be, for example, a rotary motor, or a linear motor or the like. Figure 1

[0063] The encoder 32 detects the position of the motor 31. In the case where the motor 31 is a rotary motor, the encoder 32 detects, for example, the rotation angle of the rotation shaft of the motor 31. In the case where the motor 31 is a linear motor, the encoder 32 detects, for example, the position of the movable member of the motor 31.

[0064] The encoder 32 outputs an encoded signal indicating the detected position when detecting the position of the motor 31.

[0065] As shown in FIG. 4, the motor drive device 10 is provided with a position control section 11, a correction command output section 12, a switching section 13, and a saturation processing section 14. Figure 3 The saturation processing section 14 is input with a position signal output from the displacement sensor 40, a correction signal output from the controller 20 indicating the correction amount of the position of the object 60, and a switching signal (described later) output from the controller 20, and the saturation processing section 14 (1) performs saturation processing on the position of the object 60 indicated by the position signal or the correction position of the object 60 indicated by the correction signal to output a saturated position signal or a saturated correction signal, or (2) directly outputs the input position signal or the input correction signal without performing saturation processing.

[0066] The saturation processing section 14 is input with a position signal output from the displacement sensor 40, a correction signal output from the controller 20 indicating the correction amount of the position of the object 60, and a switching signal (described later) output from the controller 20, and the saturation processing section 14 (1) performs saturation processing on the position of the object 60 indicated by the position signal or the correction position of the object 60 indicated by the correction signal to output a saturated position signal or a saturated correction signal, or (2) directly outputs the input position signal or the input correction signal without performing saturation processing.​​​

[0067] The saturation processing section 14 includes, for example, a processor (not shown) and a memory (not shown). The various functions thereof can also be implemented by the processor executing a program stored in the memory.

[0068] Figure 4 is a graph showing the relationship between the position signal before saturation processing, which is input to the saturation processing section 14, and the position signal after saturation processing, which is output from the saturation processing section 14.

[0069] In Figure 4 , the horizontal axis is the voltage of the position signal before saturation processing. The vertical axis is the voltage of the position signal after saturation processing.

[0070] As Figure 4 shown, the saturation processing section 14 performs saturation processing so that the maximum voltage of the output position signal after saturation processing is the first saturation voltage and the minimum voltage is the second saturation voltage.

[0071] Figure 5 is a graph showing the relationship between the correction amount of the position of the object 60 and the voltage in the correction signal output from the controller 20.

[0072] In Figure 5 , the horizontal axis is the correction amount Ay2 of the position of the object 60, and the vertical axis is the voltage of the analog correction signal.

[0073] As Figure 5 shown, the correction signal, which is proportional to the correction amount Ay2 of the position of the object 60, is output from the controller 20 as a voltage.

[0074] Figure 6 is a graph showing the relationship between the correction signal before saturation processing, which is input to the saturation processing section 14, and the correction signal after saturation processing, which is output from the saturation processing section 14.

[0075] In Figure 6 , the horizontal axis is the voltage of the correction signal before saturation processing, and the vertical axis is the voltage of the correction signal after saturation processing.

[0076] As Figure 6 shown, the saturation processing section 14 performs saturation processing so that the maximum voltage of the output correction signal after saturation processing is the first saturation voltage and the minimum voltage is the second saturation voltage.

[0077] The saturation processing section 14 has a function of changing the absolute values of the first saturation voltage and the second saturation voltage in such a manner that they increase with time when a switching signal is input from the controller 20.

[0078] Figure 7is a graph showing a case where the absolute value of the first saturation voltage and the absolute value of the second saturation voltage are changed in a manner that increases with time by the saturation processing section 14.

[0079] In Figure 7 , the horizontal axis is a time at which the time of the switching signal to be input is set as time 0, and the vertical axis is the voltage of the first saturation voltage and the second saturation voltage.

[0080] As Figure 7 shown, the saturation processing section 14 changes the absolute value of the first saturation voltage in a manner that linearly increases with time in such a manner that the first saturation voltage is voltage 0 at time 0 and voltage Vmax at time tl. In addition, the saturation processing section 14 changes the absolute value of the second saturation voltage in a manner that linearly increases with time in such a manner that the second saturation voltage is voltage 0 at time 0 and voltage Vmin at time tl.

[0081] Returning again to Figure 3 , the motor driving device 10 will be further described.

[0082] The correction command output section 12 is input with the position signal or the correction signal output from the saturation processing section 14, and outputs a correction position command for instructing a correction position of the motor 31 based on the position of the object 60 detected by the displacement sensor 40 indicated by the position signal or the correction amount of the position of the object 60 indicated by the correction signal.

[0083] Here, as described above, the position signal output from the displacement sensor 40 is input to the correction command output section 12 via the saturation processing section 14, that is, without passing through the controller 20. Therefore, the position of the object 60 detected by the displacement sensor 40 is fed back to a driving signal (to be described later) for driving the motor 31 without passing through the controller 20.

[0084] The correction command output section 12, for example, can include a processor (not shown) and a memory (not shown), and various functions thereof are realized by the processor executing a program stored in the memory.

[0085] The switching section 13 is input with the position command for instructing the position of the motor 31 output from the controller 20, the correction position command output from the correction command output section 12, the switching signal output from the controller 20, and the position signal output from the displacement sensor 40, and selectively outputs the position command and the correction position command. Here, the switching signal is a signal that switches the state of the switching section 13, and more specifically, a signal that switches between a first state in which the position command is selectively output and a second state in which the correction position command is selectively output.

[0086] In a case where the switch section 13 is in the first state, the motor drive device 10 is in a state of driving the motor 31 based on the position command output from the controller 20. In a case where the switch section 13 is in the second state, the motor drive device 10 is in a state of driving the motor 31 based on the position signal output from the displacement sensor 40 or the correction signal output from the controller 20. In a case where the switch section 13 is in the second state, the position command output from the controller 20 is fixed.

[0087] The switch section 13 can include, for example, a processor (not shown) and a memory (not shown), and various functions thereof can be realized by the processor executing a program stored in the memory.

[0088] The switch section 13 has the following first function to fifth function.

[0089] The first function is a function in which, when the switch section 13 is inputted, in a case where it is in the first state, a switch signal of the meaning of switching from the first state to the second state, the switch section 13 switches to the second state after a prescribed period elapses from when the switch signal is inputted. The first function is a function realized in a case where the switch section 13 is set to the first operation mode.

[0090] The second function is a function in which, when the switch section 13 is inputted, in a case where it is in the first state, a switch signal of the meaning of switching from the first state to the second state, if the position of the object 60 indicated by the position signal is not in a prescribed range, the switch section 13 switches to the second state after the position of the object 60 indicated by the position signal or the correction amount of the object 60 indicated by the correction signal becomes in the prescribed range. The second function is a function realized in a case where the switch section 13 is set to the second operation mode.

[0091] Here, whether or not the position of the object 60 indicated by the position signal or the correction amount of the object 60 indicated by the correction signal is in the prescribed range can be determined, for example, by investigating whether or not the voltage of the position signal or the correction signal is a prescribed value or more. For example, it can be determined by investigating whether or not the voltage of the position signal or the correction signal is a prescribed value or less. In addition, it can be determined by investigating whether or not the voltage of the position signal or the correction signal is a first prescribed value or more and a second prescribed value larger than the first prescribed value or less. In addition, it can be determined by investigating whether or not the voltage of the position signal or the correction signal is a first prescribed value or less or a second prescribed value larger than the first prescribed value or more.

[0092] The third function is a function in which the switching section 13, when a switching signal indicating a desire to switch from the first state to the second state is input while being in the first state, switches to the second state if the position of the object 60 indicated by the position signal is in the prescribed range for a prescribed period. The third function is a function realized when the switching section 13 is set to the third operation mode.

[0093] The fourth function is a function in which the switching section 13, when a switching signal indicating a desire to switch from the first state to the second state is input while being in the first state, switches to the second state after the position of the object 60 indicated by the position signal becomes in the prescribed range if the position of the object 60 indicated by the position signal is not in the prescribed range at a time when a prescribed period has elapsed from when the switching signal was input. The fourth function is a function realized when the switching section 13 is set to the fourth operation mode.

[0094] The fifth function is a function in which the switching section 13, when a switching signal indicating a desire to switch from the first state to the second state is input while being in the first state, switches to the second state if the position of the object 60 indicated by the position signal is in the prescribed range for a prescribed period after the first prescribed period has elapsed from when the switching signal was input. The fifth function is a function realized when the switching section 13 is set to the fifth operation mode.

[0095] The position control section 11 is input with the position command or the corrected position command selectively output from the switching section 13 and the encoding signal output from the encoder 32, and outputs a drive signal for driving the motor 31 based on the position command and the position of the motor 31 indicated by the encoding signal, or based on the corrected position command and the position of the motor 31 indicated by the encoding signal. Here, the drive signal is a current supplied to the motor 31 in order to drive the motor 31.

[0096] The position control section 11, for example, can include a processor (not shown) and a memory (not shown), and realize its various functions by the processor executing a program stored in the memory.

[0097] Returning again to Figure 1 , the sheet winding system 1 will be described.

[0098] The input device 70 receives an operation command of the sheet winding system 1 by a user using the sheet winding system 1. Then, the operation command received is output to the controller 20.

[0099] The input device 70, for example, can also realize its various functions by a personal computer having an input / output device.

[0100] The controller 20 is inputted with an operation command from the input device 70, generates a position command, a switching signal, and a correction signal based on the operation command. The generated position command, switching signal, and correction signal are outputted to the motor drive device 10.

[0101] The controller 20 can include, for example, a processor (not shown) and a memory (not shown), and various functions thereof are implemented by the processor executing a program stored in the memory.

[0102] (Action)

[0103] The following describes an action performed by the motor drive device 10 of the above-described structure.

[0104] The motor drive device 10 can perform first action state change processing to fifth action state change processing, which change the action state from a state in which the motor 31 is driven based on the position command outputted from the controller 20 to a state in which the motor 31 is driven based on the position signal outputted from the displacement sensor 40 or the correction signal outputted from the controller 20.

[0105] First, the first action state change processing is described.

[0106] Figure 8 is a flowchart of the first action state change processing.

[0107] For example, in a state in which the switching section 13 is set to the first action mode, the switching signal outputted from the controller 20, which indicates a switching of the state of the switching section 13 from the first state to the second state, is inputted to the switching section 13, whereby the first action state change processing is started.

[0108] When the first motor drive processing is started, the switching section 13 investigates whether or not the state thereof is in the first state (step S10).

[0109] In the processing of step S10, in a case where the state thereof is in the first state (step S10: "Yes"), the switching section 13 stands by until a prescribed period elapses from when the switching signal is inputted (step S20 is repeated: "No"). When the prescribed period elapses (step S20: "Yes"), the state thereof is switched from the first state to the second state (step S30). Thereby, the action state of the motor drive device 10 is changed from a state in which the motor 31 is driven based on the position command outputted from the controller 20 to a state in which the motor 31 is driven based on the position signal outputted from the displacement sensor 40 or the correction signal outputted from the controller 20.

[0110] In a case where the state of the switch unit 13 is not the first state in the process of the step S10 (step S10: "No") and in a case where the process of the step S30 ends, the motor drive device 10 ends the first operation state change process.

[0111] Figure 9 is a flowchart of the second operation state change process.

[0112] For example, in a state where the switch unit 13 is set to the second operation mode, the switch signal of the meaning to switch the state of the switch unit 13 from the first state to the second state, which is output from the controller 20, is input to the switch unit 13, and thus, the second operation state change process is started.

[0113] When the second motor drive process is started, the switch unit 13 investigates whether or not the state of the switch unit 13 is the first state (step S110).

[0114] In a case where the state of the switch unit 13 is the first state in the process of the step S110 (step S110: "Yes"), the switch unit 13 investigates whether or not the position of the object 60 indicated by the position signal is within the prescribed range (step S120).

[0115] In a case where the position of the object 60 is not within the prescribed range in the process of the step S120 (step S120: "No"), the switch unit 13 stands by until the position of the object 60 is within the prescribed range (step S120: "No" is repeated).

[0116] In a case where the position of the object 60 is within the prescribed range in the process of the step S120 (step S120: "Yes"), the switch unit 13 switches the state of the switch unit 13 from the first state to the second state (step S130). Thus, the operation state of the motor drive device 10 is changed from the state to drive the motor 31 based on the position command output from the controller 20 to the state to drive the motor 31 based on the position signal output from the displacement sensor 40 or the correction signal output from the controller 20.

[0117] In a case where the state of the switch unit 13 is not the first state in the process of the step S110 (step S110: "No") and in a case where the process of the step S130 ends, the motor drive device 10 ends the second operation state change process.

[0118] Figure 10 is a flowchart of the third operation state change process.

[0119] For example, in a state where the switch unit 13 is set to the third operation mode, the switch signal of the meaning to switch the state of the switch unit 13 from the first state to the second state, which is output from the controller 20, is input to the switch unit 13, and thus, the third operation state change process is started.

[0120] When the third motor drive processing is started, the switching section 13 investigates whether or not the own state is in the first state (step S210).

[0121] In the case where the own state is in the first state in the processing of step S210 (step S210: "Yes"), the switching section 13 stands by until the position of the object 60 indicated by the position signal is in the prescribed range for a prescribed period (step S220 is repeated: "No"). When the position of the object 60 indicated by the position signal is in the prescribed range for the prescribed period (step S220: "Yes"), the own state is switched from the first state to the second state (step S230). Thereby, the operation state of the motor drive device 10 is changed from the state of driving the motor 31 based on the position command output from the controller 20 to the state of driving the motor 31 based on the position signal output from the displacement sensor 40 or the correction signal output from the controller 20.

[0122] In the case where the own state is not in the first state in the processing of step S210 (step S210: "No") and in the case where the processing of step S230 ends, the motor drive device 10 ends the third operation state change processing.

[0123] Figure 11 is a flowchart of the fourth operation state change processing.

[0124] For example, in the state where the switching section 13 is set to the fourth operation mode, the switching signal of the meaning of switching the state of the switching section 13 from the first state to the second state output from the controller 20 is input to the switching section 13, whereby the fourth operation state change processing is started.

[0125] When the fourth motor drive processing is started, the switching section 13 investigates whether or not the own state is in the first state (step S310).

[0126] In the case where the own state is in the first state in the processing of step S310 (step S310: "Yes"), the switching section 13 stands by until a prescribed period elapses from when the switching signal is input (step S320 is repeated: "No"). When the prescribed period elapses (step S320: "Yes"), the switching section 13 investigates whether or not the position of the object 60 indicated by the position signal is in the prescribed range (step S330).

[0127] In the case where the position of the object 60 is not in the prescribed range in the processing of step S330 (step S330: "No"), the switching section 13 stands by until the position of the object 60 is in the prescribed range (step S330 is repeated: "No"). In the case where the position of the object 60 is in the prescribed range in the processing of step S330 (step S330: "Yes"), the own state is switched from the first state to the second state (step S340). Thereby, the operation state of the motor drive device 10 is changed from the state of driving the motor 31 based on the position command output from the controller 20 to the state of driving the motor 31 based on the position signal output from the displacement sensor 40 or the correction signal output from the controller 20.

[0128] In the case where the position of the object 60 is within the prescribed range in the processing of step S330 (step S330: YES), the switching section 13 switches its state from the first state to the second state (step S340). Thereby, the operation state of the motor drive device 10 is changed from the state of driving the motor 31 based on the position command output from the controller 20 to the state of driving the motor 31 based on the position signal output from the displacement sensor 40 or the correction signal output from the controller 20.

[0129] In the case where the state of the switching section 13 is not the first state in the processing of step S310 (step S310: NO) and in the case where the processing of step S340 ends, the motor drive device 10 ends the fourth operation state change processing.

[0130] Figure 12 This is a flowchart of the fifth operation state change processing.

[0131] For example, in the state where the switching section 13 is set to the fifth operation mode, the switching signal of the meaning of switching the state of the switching section 13 from the first state to the second state output from the controller 20 is input to the switching section 13, whereby the fifth operation state change processing is started.

[0132] When the fifth motor drive processing is started, the switching section 13 investigates whether or not its state is the first state (step S410).

[0133] In the case where the state is the first state in the processing of step S410 (step S410: YES), the switching section 13 stands by until a prescribed period elapses from when the switching signal is input (step S420 is repeated: NO). When the prescribed period elapses (step S420: YES), the switching section 13 stands by until the state where the position of the object 60 indicated by the position signal is within the prescribed range continues for a prescribed period (step S430 is repeated: NO). When the state where the position of the object 60 indicated by the position signal is within the prescribed range continues for the prescribed period (step S430: YES), the state is switched from the first state to the second state (step S440). Thereby, the operation state of the motor drive device 10 is changed from the state of driving the motor 31 based on the position command output from the controller 20 to the state of driving the motor 31 based on the position signal output from the displacement sensor 40 or the correction signal output from the controller 20.

[0134] In the case where the state of the switching section 13 is not the first state in the processing of step S410 (step S410: NO) and in the case where the processing of step S440 ends, the motor drive device 10 ends the fifth operation state change processing.

[0135] <Investigation>

[0136] According to the motor drive device 10, it is possible to feed back the position of the object 60 detected by the displacement sensor 40 to the drive signal without via the controller 20. Thereby, it is possible to suppress the time lag between the timing of sensing by the sensor and the timing of feeding back to the motor drive device, which is generated in the technology described in Patent Literature 1. Therefore, according to the motor drive device 10, it is possible to suppress the decrease in the control accuracy of the position of the object 60.

[0137] According to the motor drive device 10, the switching section 13 selectively outputs the position command and the correction position command. Thereby, it is possible to suppress the interference between the position command and the correction position command.

[0138] According to the motor drive device 10, the switching section 13 is able to switch to the second state after a prescribed time elapses from when the switching signal is input, when the switching signal indicating the intention to switch from the first state to the second state is input while being in the first state. Therefore, for example, it is possible to switch the switching section 13 from the first state to the second state after a period in which the operation of the displacement sensor 40 is unstable, such as a period until a time elapses after the displacement sensor 40 is just started.

[0139] According to the motor drive device 10, the switching section 13 is able to switch to the second state after the position of the object 60 detected by the displacement sensor 40 becomes within the prescribed range, when the switching signal indicating the intention to switch from the first state to the second state is input while being in the first state, if the position of the object 60 detected by the displacement sensor 40 is not within the prescribed range. Therefore, the switching section 13 automatically switches from the first state to the second state in a case where the position of the object 60 detected by the displacement sensor 40 becomes within the prescribed range. Therefore, it is possible to suppress the decrease in the control accuracy of the position of the object 60 due to the switching section 13 not switching from the first state to the second state in a case where the position of the object 60 detected by the displacement sensor 40 becomes within the prescribed range.

[0140] According to the motor drive device 10, the switching section 13 is able to switch to the second state if the state in which the position of the object 60 detected by the displacement sensor 40 is within the prescribed range continues for a prescribed period, when the switching signal indicating the intention to switch from the first state to the second state is input while being in the first state. Therefore, in a case where a phenomenon in which the signal indicating the position of the object 60 detected by the displacement sensor 40 momentarily fluctuates, such as a phenomenon in which noise in a spike shape is superimposed, occurs, it is possible to suppress the erroneous operation of the motor drive device 10 due to the phenomenon.

[0141] According to the motor drive device 10, the switching section 13, when being inputted with the switching signal indicating the intention to switch from the first state to the second state while being in the first state, can switch to the second state if the position of the object 60 detected by the displacement sensor 40 is not in the prescribed range at the time when a prescribed time has elapsed from when the switching signal is inputted. Thus, in the case where the position of the object 60 detected by the displacement sensor 40 becomes in the prescribed range after the prescribed time has elapsed, the switching section 13 automatically switches from the first state to the second state. Thus, it is possible to suppress a decrease in the control accuracy of the position of the object 60 due to the switching section 13 not switching from the first state to the second state in the case where the position of the object 60 detected by the displacement sensor 40 becomes in the prescribed range after the prescribed time has elapsed.

[0142] According to the motor drive device 10, the switching section 13, when being inputted with the switching signal indicating the intention to switch from the first state to the second state while being in the first state, can switch to the second state if the position of the object 60 detected by the displacement sensor 40 is in the prescribed range for a second prescribed period after the position of the object 60 detected by the displacement sensor 40 is in the prescribed range after a first prescribed period has elapsed from when the switching signal is inputted. Thus, in the case where a phenomenon in which the signal indicating the position of the object 60 detected by the displacement sensor 40 momentarily changes, such as a phenomenon in which noise in the shape of a spike is superimposed, occurs after the first prescribed period has elapsed, it is possible to suppress a malfunction of the motor drive device 10 due to the phenomenon.

[0143] According to the motor drive device 10, the saturation processing section 14 can perform saturation processing on the position of the object 60 detected by the displacement sensor 40, and the command output section 12 can output the second drive signal based on the position that has been subjected to the saturation processing. Thus, it is possible to suppress the occurrence of an adverse situation due to the motor 31 being sharply driven.

[0144] According to the motor drive device 10, the saturation processing section 14 can change the absolute value of the saturation value in the saturation processing in such a way that it increases with time in the case where the switching signal indicating the intention of the switching section 13 to switch from the first state to the second state is inputted. Thus, it is possible to suppress the occurrence of an adverse situation due to the motor 31 being sharply driven as a result of the switching section 13 being switched from the first state to the second state.

[0145] <Other Embodiments>

[0146] As described above, the embodiments were described as examples of the technology disclosed in the present application. However, the technology of the present disclosure is not limited to this, and can be applied to embodiments or modified examples obtained by appropriately changing, replacing, adding, omitting, and the like, without departing from the gist of the present disclosure.

[0147] (1) In the embodiment, as an example of the object 60, the object 60 is described as being provided as a sheet. However, the object 60 can be any object as long as the position thereof can be controlled by the motor 31, and need not necessarily be limited to the example of the sheet.

[0148] (2) In the embodiment, the instruction output from the controller 20 to the motor drive device 10 is described as being a position instruction for instructing the position of the motor 31. However, the instruction output from the controller 20 to the motor drive device 10 can be any instruction for driving the motor 31, and need not necessarily be limited to the example of the position instruction. For example, the instruction output from the controller 20 to the motor drive device 10 can be a speed instruction for instructing the speed of the motor 31. In this case, the position control section 11 outputs a drive signal for driving the motor 31 based on the speed instruction and the position of the motor 31 indicated by the encoding signal. For example, the instruction output from the controller 20 to the motor drive device 10 can be a torque instruction for instructing the acceleration of the motor 31. In this case, the position control section 11 outputs a drive signal for driving the motor 31 based on the torque instruction and the position of the motor 31 indicated by the encoding signal.

[0149] (3) In the embodiment, the instruction output by the correction instruction output section 12 is described as being a correction position instruction for instructing the correction position of the motor 31. However, the instruction output by the correction instruction output section 12 can be any instruction for driving the motor 31, and need not necessarily be limited to the example of the correction position instruction. For example, the instruction output by the correction instruction output section 12 can be a correction speed instruction for instructing the speed of the motor 31. In this case, the position control section 11 outputs a drive signal for driving the motor 31 based on the correction speed instruction and the position of the motor 31 indicated by the encoding signal. For example, the instruction output by the correction instruction output section 12 can be a correction torque instruction for instructing the acceleration of the motor 31. In this case, the position control section 11 outputs a drive signal for driving the motor 31 based on the correction torque instruction and the position of the motor 31 indicated by the encoding signal.

[0150] (4) In the embodiment, the displacement sensor 40 is described as being a laser displacement sensor that detects the position of the object 60 by receiving laser light. However, the displacement sensor 40 can be any sensor as long as it can detect the position of the object 60, and need not necessarily be limited to the example of the laser displacement sensor. For example, the displacement sensor 40 can be a pressure displacement sensor that detects the position of the object 60 by detecting pressure. For example, it can be a temperature displacement sensor that detects the position of the object 60 by detecting temperature. It can be an acceleration displacement sensor that detects the position of the object 60 by detecting acceleration.

[0151] (5) In the embodiment, it is described that the position command transmitted from the controller 20 to the switching section 13 is fixed in the case where the switching section 13 is in the second state. However, depending on the situation, the position command transmitted from the controller 20 to the switching section 13 does not necessarily need to be fixed, and can not be fixed.

[0152] Industrial applicability

[0153] The present disclosure can be widely used for a motor drive device that drives a motor.

[0154] Explanation of reference numerals

[0155] 1: sheet winding system; 10: motor drive device; 11: position control section; 12: correction command output section; 13: switching section; 14: saturation processing section; 20: controller; 30: position correction mechanism; 31: motor; 32: encoder; 40: displacement sensor; 50: winder; 60: object (sheet); 70: input device.

Claims

1. A motor drive device that drives a motor for controlling a position of an object based on an instruction from a controller, the motor drive device comprising: a correction instruction output section that outputs a correction instruction for correcting a position of the motor based on a position of the object detected by a displacement sensor for detecting the position of the object; a position control section that outputs a drive signal for driving the motor based on the instruction from the controller and a position of the motor detected by an encoder for detecting the position of the motor, or based on the correction instruction and the position of the motor detected by the encoder; and a switching section that selectively outputs the correction instruction and the instruction from the controller, the position control section outputs the drive signal based on the instruction or the correction instruction selectively output from the switching section and the position of the motor detected by the encoder, the switching section switches to a second state of selectively outputting the correction instruction from a first state of selectively outputting the instruction from the controller after a prescribed period elapses after the switching section is input with a switching signal indicating a desire to switch from the first state to the second state.

2. The motor drive device according to claim 1, wherein the switching section switches to the second state after the position of the object detected by the displacement sensor becomes within a prescribed range if the position of the object detected by the displacement sensor is not within the prescribed range when the switching section is input with the switching signal indicating a desire to switch from the first state to the second state while being in the first state.

3. The motor drive device according to claim 1, wherein the switching section switches to the second state if a state in which the position of the object detected by the displacement sensor is within a prescribed range continues for a prescribed period when the switching section is input with the switching signal indicating a desire to switch from the first state to the second state while being in the first state.

4. The motor drive device according to claim 1, wherein the switching section switches to the second state after the position of the object detected by the displacement sensor becomes within a prescribed range if the position of the object detected by the displacement sensor is not within the prescribed range at a time when a prescribed period elapses after the switching section is input with the switching signal indicating a desire to switch from the first state to the second state while being in the first state. wherein 5. The motor drive device according to claim 1, wherein ​ ​ ​ ​ ​ ​ ​ ​ The switching section switches to the second state of selectively outputting the correction command if, after a first prescribed period has elapsed from when the switching signal is input, the position of the object detected by the displacement sensor is within a prescribed range for a second prescribed period, when in a first state of selectively outputting the command from the controller.

6. The motor drive device according to any one of claims 1 to 5, characterized in that a saturation processing section that performs saturation processing on the position of the object detected by the displacement sensor is further provided, the correction command output section outputs the correction command based on the position that has been subjected to the saturation processing.

7. The motor drive device according to claim 6, characterized in that the saturation processing section changes the absolute value of the saturation value in the saturation processing in such a way that it increases with time when a switching signal is input for the purpose of switching the switching section from a first state of selectively outputting the command from the controller to a second state of selectively outputting the correction command.

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