A non-transitory computer-readable recording medium storing a graphic display program, a graphic display device, and a graphic display method

Abstract

The graphic display program of the present invention enables a computer to execute: a control quantity acquisition step, which, together with time information, acquires the control quantities of multiple servo motors, namely first control quantities, and the control quantity of the controlled object, namely second control quantities; and a playback step, which, based on the time information acquired together with the first control quantities, sequentially displays multiple first graphics on a display screen at a predetermined speed from a predetermined start time to an end time, and sequentially displays second graphics on other display screens in sync with the display of the first graphics, based on the time information acquired together with the second control quantities.

Description

Technical Field

[0001] This invention relates to a non-volatile computer-readable recording medium storing a graphics display program, a graphics display device, and a graphics display method used in servo control systems. Background Technology

[0002] A servo control system has multiple servo motors, which are used to drive an object with multiple drive axes. In a servo control system, control parameters such as gain values ​​are set to appropriately control the servo motors. These control parameters are evaluated and adjusted by verifying the control command values ​​for each servo motor or by using state variables (position, speed, etc.) representing the control results of each servo motor.

[0003] Regarding the confirmation of control command values ​​or state variables for each servo motor, waveforms are created and displayed on a time axis for each servo motor. These values ​​represent positions or speeds included in the control command values ​​for the servo motors, thereby allowing the understanding of temporal changes in positions or speeds. However, while confirming each servo motor using such waveforms alone is possible, it is not possible to confirm whether the controlled object is acting as intended. Therefore, the graphic display device described in Patent Document 1 displays waveforms related to each servo motor on a screen, and also displays a trajectory diagram of the target trajectory and the actual trajectory of the controlled object in a spatial coordinate system. This not only allows for the confirmation of control command values ​​for each servo motor, but also for the confirmation of the trajectory of the controlled object, enabling the evaluation of control parameters.

[0004] Patent Document 1: Japanese Patent Application Publication No. 2019-82754 Summary of the Invention

[0005] The graphic display device described in Patent Document 1 above can display a cursor on the time axis of a waveform graph related to a servo motor, and can display a trajectory graph up to the moment the cursor is positioned on the time axis. If the user drags the cursor along the time axis, the time range of the displayed trajectory graph increases or decreases accordingly. Therefore, by dragging the cursor, the user can compare the changes in the waveform graphs related to each servo motor and the trajectory graph related to the controlled object at the same moment.

[0006] However, users must drag the cursor along the timeline to check the waveforms associated with each servo motor and the trajectory diagrams associated with the controlled object, which requires a significant amount of work. Therefore, the verification of these graphs can easily become insufficient.

[0007] The present invention was proposed to solve the aforementioned problems, and its object is to provide a non-volatile computer-readable recording medium, a graphics display device, and a graphics display method that stores a graphics display program, which facilitates the verification of graphics related to servo motors and graphics related to controlled objects.

[0008] The present invention relates to a non-volatile computer-readable recording medium storing a graphic display program, characterized in that the graphic display program causes a computer to execute: a first control quantity acquisition step, for each of a plurality of servo motors, acquiring, together with timing information, a control command value for the servo motor or a state quantity representing the control result of the servo motor as a first control quantity; a second control quantity acquisition step, together with timing information, acquiring, as a second control quantity, a control command value for a controlled object driven by the plurality of servo motors or a state quantity representing the control result of the controlled object; and a first display step, performing operations on a first display screen for displaying a first graphic representing the first control quantity. The display step includes a second display screen for displaying a second graphic representing the second control quantity; a playback step for displaying the first graphic sequentially on the first display screen at a predetermined speed from a predetermined start time to an end time based on the timing information acquired together with the first control quantity, and for displaying the second graphic sequentially on the second display screen in sync with the display of the first graphic based on the timing information acquired together with the second control quantity; and a third display step for displaying a list on the third display screen, which chronologically arranges the first control quantity and the second control quantity acquired in the first control quantity acquisition step and the second control quantity acquisition step.

[0009] Furthermore, the graphic display device of the present invention is characterized by comprising: a first control quantity acquisition unit, which, together with time information, acquires a control command value for each of a plurality of servo motors or a state quantity representing the control result of the servo motor as a first control quantity; a second control quantity acquisition unit, which, together with time information, acquires a control command value for a controlled object driven by the plurality of servo motors or a state quantity representing the control result of the controlled object as a second control quantity; a first display unit, which displays a first display screen for displaying a first graphic representing the first control quantity; and a second display unit, which displays a first display screen for displaying a first graphic representing the first control quantity. A second display screen is used to display a second graphic representing a second control quantity; a playback unit displays the first graphic sequentially on the first display screen at a predetermined speed from a predetermined start time to an end time based on time information acquired together with the first control quantity, and displays the second graphic sequentially on the second display screen in sync with the display of the first graphic based on time information acquired together with the second control quantity; and a third display unit displays a list on the third display screen, which chronologically arranges the first control quantity and the second control quantity acquired by the first control quantity acquisition unit and the second control quantity acquisition unit.

[0010] Furthermore, the graphic display method of the present invention is characterized by comprising: a first control quantity acquisition step, wherein for each of a plurality of servo motors, a control command value for the servo motor or a state quantity representing the control result of the servo motor is acquired as a first control quantity together with time information; a second control quantity acquisition step, wherein a control command value for a controlled object driven by the plurality of servo motors or a state quantity representing the control result of the controlled object is acquired as a second control quantity together with time information; a first display step, wherein a first display screen for displaying a first graphic representing the first control quantity is displayed; and a second display step for displaying a first display screen for displaying a first graphic representing the first control quantity. The second display screen displays a second graphic representing the second control quantity; the playback step involves displaying the first graphic sequentially on the first display screen at a predetermined speed from a predetermined start time to an end time based on the timing information acquired together with the first control quantity, and displaying the second graphic sequentially on the second display screen in sync with the display of the first graphic based on the timing information acquired together with the second control quantity; and the third display step involves displaying a list on the third display screen, which chronologically arranges the first control quantity and the second control quantity acquired in the first control quantity acquisition step and the second control quantity acquisition step.

[0011] The effects of the invention

[0012] The present invention relates to a non-volatile computer-readable recording medium storing a graphic display program, a graphic display device, and a graphic display method that sequentially displays a first graphic at a predetermined speed and simultaneously displays a second graphic sequentially, thereby facilitating the confirmation of graphics related to servo motors and graphics related to controlled objects. Attached Figure Description

[0013] Figure 1 This is a conceptual diagram of a servo control system according to an embodiment of the present invention.

[0014] Figure 2 This is a block diagram illustrating the hardware structure of the graphics display device, controller, and servo amplifier according to embodiments of the present invention.

[0015] Figure 3 This is a block diagram illustrating the functional structure of a graphic display device according to an embodiment of the present invention.

[0016] Figure 4 This is a block diagram illustrating the functional structure of the graphics display unit of a graphics display device according to an embodiment of the present invention.

[0017] Figure 5 This is a block diagram illustrating the functional structure of the controller according to an embodiment of the present invention.

[0018] Figure 6 This is a block diagram illustrating the functional structure of the servo amplifier according to an embodiment of the present invention.

[0019] Figure 7 This diagram illustrates an example of a screen for setting recording items displayed on the display unit of a graphics display device according to an embodiment of the present invention.

[0020] Figure 8 This is a flowchart illustrating the recording item setting process of a graphic display device according to an embodiment of the present invention.

[0021] Figure 9 This is a flowchart illustrating the record item collection and processing of the controller according to an embodiment of the present invention.

[0022] Figure 10 This is a flowchart illustrating the record item collection and processing of the controller according to an embodiment of the present invention.

[0023] Figure 11 This is a flowchart illustrating the recording item collection and processing of a servo amplifier according to an embodiment of the present invention.

[0024] Figure 12 This is a flowchart illustrating the recording item collection and processing of a graphic display device according to an embodiment of the present invention.

[0025] Figure 13 This is a flowchart illustrating the graphics display processing and playback processing of a graphics display device according to an embodiment of the present invention.

[0026] Figure 14 This diagram illustrates an example of a graphic display screen displayed by the display unit of a graphic display device according to an embodiment of the present invention.

[0027] Figure 15 This diagram illustrates an example of a graphic display screen played on the display unit of a graphic display device according to an embodiment of the present invention. Detailed Implementation

[0028] Hereinafter, embodiments of the present invention will be described using the accompanying drawings. The same reference numerals in the drawings denote the same or equivalent parts.

[0029] First, use Figure 1 The structure of the servo control system 1 will be described, which includes the graphic display device 100 according to the embodiments of the present invention.

[0030] The servo control system 1 is a system that controls the driving state of a controlled object having three drive axes. The controlled object is, for example, a workpiece conveying device, which has three drive axes extending in orthogonal directions in three-dimensional space, enabling the workpiece to move in three axes.

[0031] The servo control system 1 includes a graphic display device 100, a controller 200, servo amplifiers 300a, 300b, and 300c, servo motors 400a, 400b, and 400c, and a communication line 500. The servo motors 400a, 400b, and 400c are each connected to one of the three drive axes of the controlled object, driving the controlled object. The controller 200 outputs control command values, including the coordinates and time of the controlled object's movement target position, to the servo amplifiers 300a, 300b, and 300c, causing the servo amplifiers 300a, 300b, and 300c to control the servo motors 400a, 400b, and 400c, thereby controlling the controlled object. Based on the control command values ​​received from the controller 200, the servo amplifiers 300a, 300b, and 300c control the current values, etc., output to the servo motors 400a, 400b, and 400c.

[0032] The graphic display device 100 is a device capable of graphically displaying control command values ​​or state quantities representing control results for each servo motor, and control command values ​​or state quantities representing control results for a controlled object. It includes: a liquid crystal monitor 102 for graphical display; a processing unit 101 for controlling the display state of the liquid crystal monitor 102 and performing calculations on the displayed content; and a keyboard 103 and a mouse 104 for receiving user input. This graphic display device 100 can be configured as a computer.

[0033] The graphic display device 100, controller 200, and servo amplifiers 300a, 300b, and 300c are connected via a communication line 500. The communication line 500 enables the transmission and reception of control command values, status variables representing control results, and other request signals. The communication line 500 may be, for example, a LAN (Local Area Network) cable.

[0034] Next, use Figures 2 to 6 The structures of the graphic display device 100, controller 200, and servo amplifiers 300a, 300b, and 300c constituting the servo control system 1 will be described separately. Furthermore, since servo amplifiers 300a, 300b, and 300c have the same structure, they will sometimes be described as servo amplifier 300. Similarly, servo motors 400a, 400b, and 400c will sometimes be described as servo motor 400.

[0035] First, regarding the graphics display device 100, such as Figure 2 As shown, the computing device 101 includes a processor 105, a storage device 106, and an interface 107.

[0036] The processor 105 controls the overall graphics display device 100. It reads and executes various programs, such as graphics display programs, for displaying graphics from the storage device 106.

[0037] The storage device 106 is a high-capacity, non-volatile recording medium such as an HDD (Hard Disk Drive) or SSD (Solid State Disk) that stores various programs, including a graphics display program executed by the processor 105. It also stores control command values ​​received from the controller 200, status variables indicating control results, and other request commands.

[0038] Interface 107 is a LAN port and a USB (Universal Serial Bus) port. A LAN cable, i.e., a communication line 500, is connected to the LAN port, and a USB cable 108, which connects to the LCD monitor 102, keyboard 103, and mouse 104, is connected to the USB port. Through interface 107, output signals from the computing device 101 to the controller 200 and the LCD monitor 102, and input signals from the controller 200, keyboard 103, and mouse 104 to the computing device 101 are transmitted and received.

[0039] The aforementioned graphics display program is a program that causes the computer to execute the following processing steps: the first control quantity acquisition step, the second control quantity acquisition step, the first display step, the second display step, the playback step, and the third display step. The computer, which consists of the arithmetic unit 101, the LCD monitor 102, the keyboard 103, and the mouse 104, executes the graphics display program through the processor 105, thereby functioning as the graphics display device 100.

[0040] Next, use Figure 3 The functional structure of the graphics display device 100 when the computer functions as a graphics display device 100 will be explained.

[0041] The graphics display device 100 includes a display unit 111, an operation unit 112, a communication unit 113, and a storage unit 114. The display unit 111 displays graphics and other information to the user and is composed of a liquid crystal monitor 102. The operation unit 112 receives operations from the user and is composed of a keyboard 103 and a mouse 104. The communication unit 113 transmits and receives input / output signals to the controller 200 and is composed of an interface 107. The storage unit 114 stores information such as control command values, status variables indicating control results, and other request commands received from various programs including the graphics display program and the controller 200, and is composed of a storage device 106.

[0042] In addition, the graphic display device 100 includes a control quantity acquisition unit 115 and a graphic display unit 116.

[0043] The control quantity acquisition unit 115 acquires control command values ​​for servo motors 400a, 400b, and 400c, or status quantities indicating the control results of servo motors 400a, 400b, and 400c, along with time information, from the controller 200 via the communication unit 113. Specifically, the control command values ​​for the servo motors 400 are command values ​​indicating the target movement position sent from the controller 200 to each servo amplifier 300, or current command values ​​indicating the current output from the servo amplifier 300 to the servo motor 400, etc. Specifically, the status quantities indicating the control results of each servo motor 400 are position-related feedback values ​​received by the servo amplifier 300 from the servo motor 400, etc.

[0044] Furthermore, the control quantity acquisition unit 115 has the function of acquiring, along with timing information, control command values ​​or status quantities representing the control results of controlled objects driven by servo motors 400a, 400b, and 400c from the controller 200 via the communication unit 113. The control command value for the controlled object is a coordinate value containing a numerical component, representing the target position of the controlled object in three orthogonal directions within the space where the controlled object is located. More specifically, since these three directions correspond to the drive shafts connected to the three servo motors 400, the control command value for the controlled object is a coordinate value containing a command value output from the controller 200 to each servo amplifier 300, representing the target movement position for each servo motor 400. The status quantity representing the control result of the controlled object is a coordinate value containing a numerical component, representing the actual position of the controlled object in three orthogonal directions within the space where the controlled object is located. More specifically, since the three directions mentioned above correspond to the drive shafts connected to the three servo motors 400, the state variables representing the control result for the controlled object are coordinate values ​​calculated based on the feedback values ​​of each servo motor 400a, 400b, and 400c. Alternatively, a position sensor can be installed on the controlled object itself, such as the workpiece clamping part, and its output can be converted into coordinate values ​​as the state variables representing the control result.

[0045] Here, the timing information obtained along with the control command value is timing information stored simultaneously when the control command value or a state quantity representing the control result is stored by the controller 200 or servo amplifier 300. This timing information is obtained from the internal clock 213 of the controller 200 (see reference 213). Figure 5 ) or the internal clock 313 of the servo amplifier 300 (refer to) Figure 6 The moment it was achieved.

[0046] Furthermore, the control command value or state quantity representing the control result of each servo motor 400 corresponds to the first control quantity. The control quantity acquisition unit 115, which acquires the first control quantity and timing information, corresponds to the first control quantity acquisition unit. Additionally, the control command value or state quantity representing the control result for the controlled object corresponds to the second control quantity. The control quantity acquisition unit 115, which acquires the second control quantity and timing information, corresponds to the second control quantity acquisition unit. Sometimes, the first and second control quantities are collectively referred to as the control quantity.

[0047] The graphics display unit 116 controls the display unit 111 to display graphics and list the aforementioned control quantities. Its detailed configuration is as follows: Figure 4 As shown.

[0048] The graphics display unit 116 includes a waveform display unit 120, a trajectory display unit 121, a list display unit 122, and a playback unit 123.

[0049] The waveform display unit 120 has the function of displaying a display screen for displaying a graph representing the first control quantity on the display unit 111. This display screen is displayed on a portion of the screen of the display unit 111, i.e., the liquid crystal monitor 102. The waveform display unit 120 has the function of displaying a time axis and an axis of the first control quantity orthogonal to the time axis on the display screen, and displaying a still image of the graph (hereinafter referred to as a waveform) representing the relationship between the first control quantity and time, unless playback processing is performed by the playback unit 123 described later. Furthermore, the waveform display unit 120 receives user selections and can display waveforms for each of the servo motors 400a, 400b, and 400c, or only the waveform of the servo motor 400 selected by the user. In this embodiment, the user selects the display of the waveforms for each of the servo motors 400a, 400b, and 400c.

[0050] Furthermore, the waveform display unit 120 corresponds to the first display unit, and the displayed screen corresponds to the first display screen. Additionally, the displayed waveform corresponds to the first graphic.

[0051] The trajectory display unit 121 has the function of displaying a display screen on the display unit 111 that displays a graph representing a second control quantity indicating a controlled object. This display screen is displayed on a portion of the screen of the display unit 111, i.e., the liquid crystal monitor 102, and is in an area different from the first display screen described above. The trajectory display unit 121 has the function of displaying three orthogonal axes representing the position of the controlled object on the display screen, and displaying a graph (hereinafter referred to as a trajectory diagram) representing the trajectory of the controlled object as a still image based on the second control quantity, unless playback processing is performed by the playback unit 123 described later.

[0052] Furthermore, the aforementioned trajectory display unit 121 corresponds to the second display unit, and the aforementioned display screen corresponds to the second display screen. Additionally, the displayed trajectory diagram corresponds to the second graphic.

[0053] The playback unit 123 has the function of playing waveform diagrams and trajectory diagrams. Specifically, the playback unit 123 has the function of playing back waveform diagrams; that is, if it receives a playback processing operation from the user, it sets the waveform diagram displayed on the waveform diagram display unit 120 to be hidden, and displays multiple waveform diagrams sequentially from a predetermined start time to a predetermined end time at a predetermined speed based on the time information obtained by the control quantity acquisition unit 115 along with the first control quantity for each of the servo motors 400a, 400b, and 400c. Furthermore, if the user selects to display only a portion of the servo motors 400, the waveform diagram of the selected servo motor is played back. In addition, the playback unit 123 has the function of playing back waveform diagrams simultaneously, and based on the time information obtained by the control quantity acquisition unit 115 along with the second control quantity for the controlled object, sequentially displays trajectory diagrams and waveform diagrams synchronously.

[0054] In addition, the playback unit 123 can display graphics at a speed different from the speed predetermined above, and has the function of allowing the user to select one of the speeds and play it at the selected speed.

[0055] The list display unit 122 has the function of displaying a display screen for displaying a list on the display unit 111. This list sequentially arranges the control quantities of the servo motors 400 (servo motors 400a, 400b, and 400c in this embodiment) and the controlled objects, selected by the user for display as waveforms. This display screen is displayed on a portion of the screen of the display unit 111, i.e., the LCD monitor 102, and in an area different from the first and second display screens described above. The list display unit 122 has the function of displaying the list on this display screen. Furthermore, when playback processing is performed by the playback unit 123 (described later) and a waveform and trajectory diagram of the playback time between the start and end times are displayed, the list display unit 122 has the function of displaying, respectively, the control quantities among the first control quantities included in the list that have time information closest to the playback time, and the control quantities among the second control quantities included in the list that have time information closest to the playback time, in a display format different from the other control quantities. Displaying it in different ways, such as using bold text or highlighting, refers to displaying only the control value.

[0056] Furthermore, the list display unit 122 corresponds to the third display unit, and the screen displayed by the list display unit corresponds to the third display screen.

[0057] The structure of the graphics display device 100 has been described above. Next, using... Figure 2 and Figure 5 The structure of controller 200 is described.

[0058] like Figure 2 As shown, the controller 200 has a processor 201, a storage device 202 and an interface 203. The controller 200 is also referred to as a programmable logic controller.

[0059] The processor 201 controls the controller 200 as a whole. It reads and executes various programs from the storage device 202, such as programs for controlling the servo motor 400 and programs for obtaining control values ​​to be sent to the graphics display device 100.

[0060] The storage device 202 is a high-capacity, non-volatile recording medium such as an HDD (Hard Disk Drive) or SSD (Solid State Disk) that stores various programs executed by the processor 201. Additionally, it stores control quantities such as control command values ​​sent from the controller 200 to the servo amplifier 300 and status quantities representing control results obtained from the servo amplifier 300.

[0061] Interface 203 is a LAN port, and a LAN cable, i.e., communication line 500, is connected to the LAN port. Through interface 203, input signals from the graphics display device 100 and the servo amplifier 300, as well as output signals from the controller 200 to the graphics display device 100 and the servo amplifier 300, are transmitted and received.

[0062] Next, use Figure 5 The functional structure of the controller 200 is described.

[0063] The controller 200 includes a storage unit 211, a communication unit 212, and an internal clock 213. The storage unit 211, consisting of a storage device 202, stores various programs and control quantities. The communication unit 212, consisting of an interface 203, handles the transmission and reception of inputs and outputs to the graphics display device 100 and the servo amplifier 300. The internal clock 213 provides timing information when control quantities are stored in the storage unit 211 and is synchronized with the internal clock 313 of the servo amplifier 300 (described later).

[0064] The controller 200 also includes a control instruction unit 214 and a control recording unit 215. The control instruction unit 214 has the function of generating control instruction values ​​to be sent to each servo amplifier 300, and causing the communication unit 212 to send the control instruction values.

[0065] The control recording unit 215 has the function of temporarily storing a first control quantity and a second control quantity obtained by the graphics display device 100 through sending a request in the storage unit 211. Specifically, the control recording unit 215 stores the control command values ​​of each servo amplifier 300 generated by the control command unit 214, the control command values ​​generated by each servo amplifier 300 obtained from each servo amplifier 300 via the communication line 500 and the communication unit 212, and the feedback values ​​of each servo motor 400 as the first control quantity in the storage unit 211. In addition, the control recording unit 215 stores the coordinate values ​​of the target position of the controlled object calculated based on the control command values ​​of each servo amplifier 300, and the coordinate values ​​of the actual position of the controlled object calculated based on the feedback values ​​of each servo motor 400 as the second control quantity in the storage unit 211. Furthermore, as will be described later, the control quantity to be stored is determined based on the recording item output from the control quantity acquisition unit 115 of the graphics display device 100.

[0066] The structure of controller 200 has been described above. Next, using... Figure 2 and Figure 6 The structure of the servo amplifier 300 is described.

[0067] like Figure 2 As shown, the servo amplifier 300 has a processor 301, a storage device 302 and an interface 303. It generates position command value, speed command value and current command value based on the control command value output from the controller 200, determines the current value to be output to the servo motor 400, and outputs the current value to the servo motor 400, thereby controlling the servo motor 400.

[0068] The processor 301 controls the servo amplifier 300 as a whole. It reads and executes various programs from the storage device 302, such as programs for controlling the servo motor 400 and programs for obtaining control values ​​to be sent to the controller 200.

[0069] The storage device 302 is a high-capacity, non-volatile recording medium such as an HDD (Hard Disk Drive) or SSD (Solid State Disk) that stores various programs executed by the processor 301. Additionally, it stores control command values ​​such as position command values, speed command values, and current values ​​used to control the servo motor 400. Furthermore, it stores feedback values ​​obtained from the servo motor 400 as state variables representing the control results.

[0070] Interface 303 is a LAN port and a current control device for the servo motor 400. The LAN port is connected to a LAN cable, i.e., a communication line 500. Input signals from the controller 200 and output signals from the servo amplifier 300 to the controller 200 are transmitted and received through interface 203.

[0071] Next, use Figure 6 The functional structure of the servo amplifier 300 is explained.

[0072] The servo amplifier 300 includes a storage unit 311, a communication unit 312, and an internal clock 313. The storage unit 311, consisting of a storage device 302, stores various programs and control quantities. The communication unit 312, consisting of an interface 303, handles the transmission and reception of inputs and outputs to the controller 200. The internal clock 313 provides timing information when control quantities are stored in the storage unit 311 and synchronizes with the internal clock 213 of the controller 200.

[0073] The servo amplifier 300 also includes a positioning control unit 314 and a control recording unit 315. The positioning control unit 314 generates position command values, speed command values, and current command values ​​based on control command values ​​received from the controller 200, determines the current value to be output to the servo motor 400, and outputs a current corresponding to that current value to the servo motor 400. The control recording unit 315 stores the position command values, speed command values, and current command values ​​generated by the positioning control unit 314 in a storage unit 311. Furthermore, the control recording unit 315 stores feedback values ​​from the servo motor 400 related to the position, speed, and current values ​​in the storage unit 311.

[0074] The structure of the graphic display device 100, etc., constituting the servo control system 1 has been described above. Next, using... Figures 7 to 11 The process by which the graphic display device 100 obtains control quantities in order to display a graphic on the display unit 111 will be explained.

[0075] The control values ​​acquired by the control value acquisition unit 115 of the graphics display device 100 are collected by the controller 200 and the servo amplifier 300. Therefore, firstly, the user selects the control value they wish to graphically represent, and upon receiving the selection, the control value acquisition unit 115 requests the controller 200 to set the control value required for the graphical display as a recording item. Figure 7 and Figure 8 This document explains the settings and processing for this record item.

[0076] First, if the user operates the graphic display device 100 to set recording items, then... Figure 7 The recording settings shown are displayed on the display unit 111 on screen 130, then the recording begins. Figure 8 The flowchart shows the record item setting process.

[0077] Figure 7The recording item setting screen 130 includes a get button 131, a recording item list 132, and a set button 133. The recording item list 132 displays a list of selectable items when the user selects a recording item. Figure 7 The example shows that record item list 132 has been created, but... Figure 8 The flowchart processing begins at the initial stage, before the list has been created and displayed.

[0078] If a user clicks the "Get" button 131 to display the items that can be selected as record items in the record item list 132, then... Figure 8 As shown in the flowchart, the control quantity acquisition unit 115 determines that the acquisition button 131 has been pressed (YES in step S101) and sends an acquisition request signal capable of recording items to the request communication unit 113 of the controller 200 (step S102). Furthermore, the control quantity acquisition unit 115 repeats the determination in step S101 until the acquisition button 131 is clicked.

[0079] The controller 200 stores a list of recordable items that can be recorded by the controller 200 itself and the controlled servo amplifier 300. If a request is received from the control quantity acquisition unit 115, information indicating recordable items is sent to the control quantity acquisition unit 115. Upon receiving this information, the control quantity acquisition unit 115 displays the recordable items in the record item list 132 (step S103). Thus, the state with the list of recordable items displayed is... Figure 7 The recording item setting screen 130 shows the controller name in the left column as the device name and the control quantity in the right column as the items that can be recorded.

[0080] Regarding the record item list 132, the user can select each record item using a mouse 104 or the like, and the control quantity acquisition unit 115 receives the record item selection from the user (step S104). After the user selects a record item, they click the setting button 133 to confirm the selection. Therefore, when the user clicks the setting button 133, the control quantity acquisition unit 115 determines that the setting button has been pressed (YES in step S105) and continues to receive record item selections until the click occurs (NO in step S105).

[0081] After the setting button 133 is clicked, the control quantity acquisition unit 115 stores the recorded item selected by the user in the storage unit 114 (step S106) and sends the recorded item to the controller 200 (step S107). The controller 200 stores the received recorded item in the storage unit 211. Thus, the recorded item setting process is completed.

[0082] Once the recording items are set up, the controller 200 begins collecting the recording items, i.e., the control quantities. Specifically, if the settings are complete, the process repeats at a fixed period. Figure 9 The processing of flowcharts.

[0083] like Figure 9 As shown, the control recording unit 215 of the controller 200 first reads the set recording item from the storage unit 211 (step S111). Then, the control recording unit 215 causes the communication unit 212 to send a recording item transmission request signal to the servo amplifier 300. The processing of the servo amplifier 300 upon receiving the transmission request signal will be described later (see reference). Figure 11 If the servo amplifier 300 sends data corresponding to the recording item in response to the transmission request signal, the control recording unit 215 receives the data via the communication unit 212 and stores it in the storage unit 211 (step S113). Furthermore, here, if it is necessary to calculate the coordinate values ​​of the position based on the feedback value, the calculation is performed and stored in the storage unit 211.

[0084] In addition, the control recording unit 215 of the controller 200 also conforms to Figure 10 The flowchart processing stores the control command values ​​generated by the controller 200 itself. This processing begins when the controller 200 generates control command values. First, the control recording unit 215 reads a record item from the storage unit 211 (step S121). Then, the control recording unit 215 determines whether the generated control command value is included in the record item read from the storage unit 211 (step S122). If it is included in the record item (YES in step S122), the control command value is stored in the storage unit 211 along with time information (step S123). Furthermore, when it is necessary to calculate the position coordinates based on the control command value, calculations are performed and stored in the storage unit 211.

[0085] Next, use Figure 11 The collection and processing of control quantities in the servo amplifier 300 is described. Starting with a fixed period... Figure 11 The processing of flowcharts.

[0086] First, the control recording unit 315 of the servo amplifier 300 sends a transmission request signal to the servo motor 400 to send a feedback value (step S131). Then, if a feedback value is received from the servo motor 400, the timing information is obtained with reference to the internal clock 313, and the feedback value and the timing information are stored together in the storage unit 311 (step S132).

[0087] Then, the control recording unit 315 determines whether a transmission request signal has been received from the controller 200 (step S133). Figure 9 In step S112, the send request signal is sent from the controller 200.

[0088] Upon receiving a transmission request signal (in the case of YES in step S133), the control recording unit 315 reads the data corresponding to the recording item specified by the transmission request signal from the storage unit 311 (step S134) and sends it to the controller 200 (step S135). Afterwards, on the controller 200 side, as described above, the data received by the controller 200 is stored in the storage unit 211. Figure 9 Step S113).

[0089] If no transmission request signal is received (in the case of NO in step S133), the control recording unit 315 will not read or transmit data and will end the process.

[0090] In addition, the position command value, speed command value and current command value generated by the servo amplifier 300 for controlling the servo motor 400 are also pre-stored in the storage unit 311 when they are generated, and sent to the controller 200 when there is a transmission request signal from the controller 200.

[0091] Based on the above Figures 9 to 11 The controller 200 collects the control command values ​​sent by the controller 200 to each servo amplifier 300 for each servo motor 400, the control command values ​​sent by each servo amplifier 300 to each servo motor 400, and the status variables representing the control results for each servo motor 400, i.e., the feedback values ​​from the servo motor 400, as the first control variable and the second control variable data.

[0092] Next, use Figures 12 to 15 The process by which the graphic display device 100 displays graphics using the control command values ​​and feedback values ​​(i.e., control quantities) collected by the controller 200 will be described.

[0093] Figure 12 The flowchart illustrates the process by which the graphics display device 100 collects control signals and timing information from the controller 200 to create a graphic. This process begins when the graphics display device 100 receives an operation from the user to create a graphic. The control signal acquisition unit 115 of the graphics display device 100 reads the recorded items and controller 200 information set in the controller 200 from the storage unit 114 to collect control signals from the controller 200 (step S141). These recorded items and controller 200 information are stored in... Figure 8 The settings are recorded in step S106 of the flowchart for the processing of the project.

[0094] Next, the control quantity acquisition unit 115, using the controller shown in the information of the controller 200 as the receiving target, generates a transmission request signal and sends it to the communication unit 113. The transmission request signal is used to request the transmission of data corresponding to the recording item (step S142). Then, the data corresponding to the recording item is received from the controller 200 and stored in the storage unit 114 (step S143). Furthermore, this data includes not only the control quantity but also time information stored along with the control quantity.

[0095] In addition, Figure 12 Steps S141 to S143 shown are collectively referred to as control quantity acquisition steps. Furthermore, since the control quantity acquired by the control quantity acquisition unit 115 includes a first control quantity and a second control quantity, the control quantity acquisition steps are referred to as the first control quantity acquisition steps when the focus is on acquiring the first control quantity, and as the focus is on acquiring the second control quantity, they are referred to as the second control quantity acquisition steps.

[0096] As described above, if the graphics display device 100 obtains a control quantity, then according to Figure 13 The flowchart shows the process of displaying and playing graphics starting from the graphics display device 100.

[0097] The waveform display unit 120 of the graphics display device 100 receives information about the waveform that the user wishes to create. Specifically, the waveform information indicates which control quantity is associated with which waveform to create, and includes information about multiple waveforms if the user wishes to create multiple waveforms. In this embodiment, the creation of waveforms associated with servo motors 400a, 400b, and 400c is selected, but selections associated with a portion of the servo motors 400 can also be made. If the waveform display unit 120 receives the waveform information, it displays a waveform display screen (first display screen) on a portion of the screen of the display unit 111, i.e., the liquid crystal monitor 102. In this display screen, the axis of the control quantity corresponding to the displayed waveform is displayed as the vertical axis. The time axis is displayed as the horizontal axis, orthogonal to the axis of the control quantity. Furthermore, the waveform display unit 120 reads the waveform information related to the control quantity and the control quantity. Figure 12 In step S143, the control quantity and timing information contained in the data corresponding to the recorded items stored in the storage unit 114 are used to generate a waveform diagram and display it on the display screen (step S151).

[0098] Furthermore, step S151 corresponds to the first displayed step.

[0099] Next, the trajectory display unit 121 of the graphics display device 100 displays a trajectory display screen (second display screen) in a portion of the screen of the display unit 111, i.e., the liquid crystal monitor 102, and in an area that does not overlap with the waveform display screen. Furthermore, this display screen displays three orthogonal axes used to represent three-dimensional space. These three orthogonal axes represent the spatial positions of the controlled object that can be moved. The trajectory display unit 121 reads the waveform and the waveform display screen... Figure 12 In step S143, the data corresponding to the recorded items stored in the storage unit 114 includes the coordinate values ​​and time information of the target or actual position of the controlled object. Based on these coordinate values ​​and time information, a trajectory diagram is generated and displayed on the aforementioned display screen (step S152).

[0100] Furthermore, step S151 corresponds to step 2 shown.

[0101] exist Figure 14 The image shown is an example of a display unit 111, i.e., a liquid crystal monitor 102, that displays waveform and trajectory diagrams as described above.

[0102] In the overall display screen, the left side serves as the graphics display screen, and the three graphics display screens at the top are waveform display screens 141, 142, and 143. In this example, in the first waveform display screen 141, the user selects to display a graph related to the actual current position of the servo motor 400 driving axis 1. The vertical axis is set to the axis of the actual current position of the servo motor 400 driving axis 1, and the horizontal axis is set to the time axis. Axis 1 is one of the three axes of the controlled object. Additionally, a waveform graph related to the actual current position of the servo motor 400 driving axis 1 is displayed.

[0103] In the second waveform display screen 142, a graph related to the actual current position of the servo motor 400 driving axis 2 is displayed, selected by the user. The vertical axis is set to the axis of the actual current position of the servo motor 400 driving axis 2, and the horizontal axis is set to the time axis. Axis 2 is one of the three axes of the controlled object. Additionally, a waveform graph related to the actual current position of the servo motor 400 driving axis 2 is displayed.

[0104] In the third waveform display screen 143, a graph related to the actual current position of the servo motor 400 driving axis 3 is displayed based on user selection. The vertical axis is set to the axis of the actual current position of the servo motor 400 driving axis 3, and the horizontal axis is set to the time axis. Axis 3 is one of the three axes of the controlled object. Additionally, a waveform graph related to the actual current position of the servo motor 400 driving axis 3 is displayed.

[0105] Additionally, below the three waveform display screens 141, 142, and 143 is the trajectory display screen 144. The trajectory display screen 144 displays three axes representing the position of the controlled object in the configured space, and displays a trajectory diagram representing the trajectory of the controlled object.

[0106] Furthermore, the list display unit 122 of the graphics display unit 116 displays the display screen (third display screen) used for list display in an area that does not overlap with the area that becomes the graphics display screen. Figure 14 In the example, it is shown on the right side of each graph. The list display unit 122 displays a graph setting list 145 that represents the content of the displayed graph, and a control record list 146 that displays the control quantities corresponding to the axes used in the waveform graph and trajectory graph in sequence.

[0107] The graph setting list 145 lists the information of the graphs displayed on waveform display screens 141, 142, 143 and trajectory graph display screen 144. The displayed graphs are numbered 1, 2, 3, and 4 from top to bottom in the order they appear, and these numbers are displayed in the leftmost column (the NO. column). The graph name is displayed in the column to the right of the NO. column. The graph name can be entered and changed by the user. A category column is displayed to the right of the graph name column, indicating whether the graphs with NO. 1, 2, 3, and 4 are waveform graphs or trajectory graphs. Regarding the category, user input can be received, or the category can be automatically determined and displayed based on whether the graph includes a time axis. A column for item 1, item 2, and item 3 is displayed to the right of the category column (in...). Figure 14 The column for item 3 is hidden and can be displayed by manipulating the slider below the list. The column for item 1 displays the names of the axes representing the control quantities shown in the waveform graph and the name of one axis shown in the trajectory graph. The columns for items 2 and 3 display the names of the remaining axes shown in the trajectory graph. These axis names can be input by the user or read from the output. Figure 7 The name of the record item stored in the storage unit 114 in step S106 of the flowchart (refer to...) Figure 6 The list 132 is displayed.

[0108] Control record list 146 is a list that arranges the control quantities corresponding to the axes of the displayed waveform and trajectory graphs in chronological order. When arranged chronologically, the time shown by the time information stored along with the control quantities is used. The leftmost column in control record list 146 is the time column, displaying the times sequentially. In the columns to the right of the time column, there is a column displaying control commands, showing what kind of control command was performed on the controlled object. This control command is displayed based on user input. Additionally, the control quantities corresponding to the displayed times are displayed in the three columns to the right of the control command column. Furthermore, in... Figure 14 The example shows the control variables corresponding to the respective axes of the waveform graph. The three axes of the trajectory graph are common to the axes of the waveform graph, so they have been omitted.

[0109] Next, return to Figure 13 The flowchart illustrates the graphics playback processing performed by the graphics display device 100.

[0110] From the moment the user receives the start operation for playback processing, the waveform display unit 120 and the trajectory display unit 121 to the playback unit 123 continuously display a static image (NO in step S153). If the user initiates the playback process, the playback unit 123 determines that a playback operation exists (YES in step S153) and stops the waveform display unit 120 and the trajectory display unit 121 from displaying the waveform and trajectory. Then, the playback unit 123 reads the control quantity and timing information selected as the waveform to be displayed from the storage unit 114, and displays the waveform sequentially from the time consistent with the start time to the time consistent with the end time based on the control quantity and the timing information (step S154). During the start operation of playback processing, the user can input the start time and the end time.

[0111] Additionally, the playback unit 123 reads the control quantities and timing information required to display the trajectory graph from the storage unit 114, and displays the trajectory graph sequentially in sync with the display of the waveform graph based on the control quantities and timing information (step S155).

[0112] Furthermore, steps S154 and S155 are collectively referred to as the playback steps.

[0113] exist Figure 14In the example, the playback processing of the graphics is performed on the operation screen 147 in the lower right corner. The operation screen 147 includes a play / pause button 148, a slow play / pause button 149, and a stop button 150, which the user can operate using the mouse 104. If the user clicks the play / pause button 148 once, it is considered an acceptance of the start operation for playback processing, and playback processing by the playback unit 123 begins. If clicked again, the playback unit 123 pauses the display of the graphics. Similarly, the slow play / pause button 149 operates on the playback and stop functions implemented by the playback unit 123, but the graphics are played at a slower speed compared to clicking the play / pause button 148. Furthermore, if the stop button 150 is clicked, the playback of the graphics is reset, the graphics return to the starting point, and playback stops.

[0114] Here, in Figure 15 The image shows the graphics being played. Figure 15 The diagram on the left shows the initial stage of playback, and the diagram on the right shows the final stage. That is, the left diagram is earlier than the right diagram. Figure 15 As shown, if the play / pause button 148 or the slow play / pause button 149 is clicked, the waveform will be played on the waveform display screens 141, 142... and the trajectory will be played on the trajectory display screen 144.

[0115] Return to Figure 14 Continuing with the explanation of operation screen 147. Operation screen 147 includes a start time 151, an end time 152, a slider 153, and a display time 154. The start time 151 and end time 152 can be entered by clicking, thus setting the start and end times. In addition to playing via the play / pause button 148 or the slow play / pause button 149, the operation screen 147 also allows for graphics playback by dragging the slider 153. At display time 154, the time of the graphics played is displayed, and a specific control value from the control record list 146 is displayed in a different format than other rows, such as bold text or highlighting. This specific control value corresponds to the time information representing the closest time to that time.

[0116] Furthermore, the timing of the graphics played via the playback display corresponds to the playback timing. Additionally, the following process is referred to as the third display step: the process by which the list display unit 122 displays the control record list 146 on the third display screen as described above; and the process by which a row of specific control quantities among the control quantities contained in the control record list 146 is displayed in a display format different from other rows, wherein the specific control quantity corresponds to timing information representing the timing closest to the playback timing.

[0117] The graphics display program, graphics display device 100, and graphics display method according to Embodiment 1 of the present invention are configured as described above, and the following effects are achieved.

[0118] The graphic display program, graphic display device 100, and graphic display method sequentially display graphics related to the first control quantity of the servo motor 400 at a predetermined speed, and also synchronously display graphics related to the second control quantity of the controlled object. Therefore, there is no need to perform dragging operations to play the graphics, and it is easy to perform the confirmation operation of graphics related to the servo motor and graphics related to the controlled object.

[0119] The graphic display program, graphic display device 100, and graphic display method enable the synchronous and sequential display of waveform diagrams and trajectory diagrams. The waveform diagram represents the relationship between the control quantity of the servo motor 400 and time, while the trajectory diagram is generated based on values ​​representing the position of the controlled object in three-dimensional space. Therefore, both the control state of the servo motor and the control state of the controlled object can be confirmed in a time-matched manner, and the control parameters of the servo control system can be easily adjusted.

[0120] The graphics display program, graphics display device 100, and graphics display method can not only display waveforms and trajectory diagrams sequentially at a predetermined speed, but also play them at a speed different from that speed. Therefore, since the user can select a suitable speed for playback, it is easy to perform confirmation operations on graphics related to servo motors and graphics related to the controlled object.

[0121] The graphical display program, graphical display device 100, and graphical display method can display waveform diagrams and trajectory diagrams, and can also display a list of control quantities arranged in sequence for each diagram. Therefore, users can understand the movement of the servo motor 400 or the controlled object through the graphics, and can adjust the control parameters of the servo control system with high precision by observing the values ​​in the list.

[0122] The graphic display program, graphic display device 100, and graphic display method can display the control quantities corresponding to the playback time of the graphic in a list of control quantities arranged in sequence for each graphic, using a display format different from other control quantities. Therefore, users can more easily grasp the values ​​in the list corresponding to the graphic and can easily and accurately adjust the control parameters of the servo control system.

[0123] Here, we will describe and supplement the description of variations of the graphics display program, graphics display device 100 and graphics display method according to the embodiments of the present invention.

[0124] In the embodiments, examples of conveying devices capable of transporting workpieces in three dimensions are given as the controlled object, but two-dimensional conveying devices are also possible, as well as devices that move elements other than the workpiece, such as processing tools. Additionally, robotic arms with multiple drive axes are also possible.

[0125] Furthermore, there can be multiple controlled objects, and the number of controllers 200 can also match the number of controlled objects or the content being controlled. In this case, the graphic display device 100 sets the recording items for each controller 200 and collects the recording items from each controller 200. Even when there are multiple controllers 200, the graphic display device 100 can centrally collect control quantities and display them graphically, thus improving user convenience.

[0126] Furthermore, even if the controllers 200 are out of sync, as long as the graphics display device 100 is aware of the time differences of each controller 200, the time information differences of each controller 200 can be corrected.

[0127] In addition, in the implementation method, it is explained that the control command value and the state quantity representing the control result mainly represent position, but can also represent speed and acceleration.

[0128] In one embodiment, the waveform display unit 120 and the trajectory display unit 121 display the waveform and trajectory on the display unit 111, but the graphics display unit 116 may also receive input of any graphic form and axis from the user and display multiple graphics selected by the user.

[0129] Industrial applicability

[0130] The graphics display program, graphics display device, and graphics display method of the present invention can be used when adjusting the control parameters of a servo control system.

[0131] Explanation of the label

[0132] 1. Servo control system; 100. Graphic display device; 101. Calculation unit; 102. LCD monitor; 103. Keyboard; 104. Mouse; 105. Processor; 106. Storage device; 107. Interface; 108. USB cable; 111. Display unit; 112. Operation unit; 113. Communication unit; 114. Storage unit; 115. Control quantity acquisition unit; 116. Graphic display unit; 120. Waveform display unit; 121. Track graph display unit; 122. List display unit; 123. Playback unit; 130. Screen for setting recording items; 131. Acquisition button; 132. Recording item list; 133. Setting button; 141. Waveform display screen; 142. Waveform display screen; 143. Waveform display screen; 144. Track graph display screen; 145. Graphic setting list; 146. Control recording list; 147. Operation screen; 148. Play / Pause. Buttons, 149 Slow Play / Pause Button, 150 Stop Button, 151 Start Time, 152 End Time, 153 Slider, 154 Display Time, 200 Controller, 201 Processor, 202 Storage Device, 203 Interface, 211 Storage Unit, 212 Communication Unit, 213 Internal Clock, 214 Control Command Unit, 215 Control Recording Unit, 300 Servo Amplifier, 301 Processor, 302 Storage Device, 303 Interface, 311 Storage Unit, 312 Communication Unit, 313 Internal Clock, 314 Positioning Control Unit, 315 Control Recording Unit, 400 Servo Motor, 500 Communication Line

Claims

1. A non-transitory computer-readable recording medium storing a graphic display program that causes a computer to execute: a first control amount acquisition step of acquiring, for each of a plurality of servo motors, a control command value for the servo motor or a state amount indicating a control result of the servo motor as a first control amount together with time information; a second control amount acquisition step of acquiring a control command value for a control target driven by the plurality of servo motors or a state amount indicating a control result of the control target as a second control amount together with time information; a first display step of displaying a first display screen for displaying a first graph indicating the first control amount; a second display step of displaying a second display screen for displaying a second graph indicating the second control amount; a playback step of displaying the first graph on the first display screen at a predetermined speed in order from a predetermined start time to an end time based on the time information acquired together with the first control amount, and displaying the second graph on the second display screen in synchronization with the display of the first graph based on the time information acquired together with the second control amount; and a third display step of displaying a list on a third display screen, the list arranging the first control amount and the second control amount acquired in the first control amount acquisition step and the second control amount acquisition step in chronological order, and displaying a specific first control amount included in the first control amount and a specific second control amount included in the second control amount in a display form different from other first control amounts and second control amounts in a case where the first graph at a playback time between the start time and the end time is displayed while the first graph is displayed in order from the start time to the end time in the playback step, the specific first control amount being a first control amount whose time indicated by the time information acquired together with the first control amount is closest to the playback time, and the specific second control amount being a second control amount whose time indicated by the time information acquired together with the second control amount is closest to the playback time.

2. The computer-readable recording medium according to claim 1, wherein the second control amount acquired in the second control amount acquisition step is a numerical value indicating a respective target or actual position of the control target in a plurality of directions orthogonal in a space in which the control target is disposed, the first graph is a graph indicating a relationship between the first control amount of the servo motor and time, and the second graph is a graph indicating a trajectory of the control target generated based on the numerical value indicating the position.

3. The computer-readable recording medium according to claim 1 or 2, wherein ​ ​ ​ ​ ​ ​ ​ ​ ​ In the playback step, the first graphics can be sequentially displayed at a speed different from the predetermined speed, and the user can be allowed to select between the predetermined speed and the different speed, so that the first graphics are sequentially displayed at the speed selected by the user.

4. A graphic display device, comprising: a first control amount acquisition section that acquires, for each of a plurality of servo motors, a control command value for the servo motor or a state amount indicating a control result of the servo motor as a first control amount, together with time information; a second control amount acquisition section that acquires a control command value for a control target driven by the plurality of servo motors or a state amount indicating a control result of the control target as a second control amount, together with time information; a first display section that displays a first display screen for displaying a first graphic representing the first control amount; a second display section that displays a second display screen for displaying a second graphic representing the second control amount; a playback section that sequentially displays the first graphics on the first display screen at a predetermined speed from a predetermined start time to an end time based on the time information acquired together with the first control amount, and sequentially displays the second graphics on the second display screen in synchronization with the display of the first graphics based on the time information acquired together with the second control amount; and a third display section that displays a list in which the first control amounts acquired by the first control amount acquisition section and the second control amounts acquired by the second control amount acquisition section are arranged in chronological order, and displays a specific first control amount included in the list and a specific second control amount included in the list in a display form different from other first control amounts and second control amounts in a case where the first graphics at playback times between the start time and the end time are displayed while the playback section sequentially displays the first graphics from the start time to the end time.

5. A graphic display method, comprising: a first control amount acquisition step of acquiring, for each of a plurality of servo motors, a control command value for the servo motor or a state amount indicating a control result of the servo motor as a first control amount, together with time information; a second control amount acquisition step of acquiring a control command value for a control target driven by the plurality of servo motors or a state amount indicating a control result of the control target as a second control amount, together with time information; a first display step of displaying a first display screen for displaying a first graphic representing the first control amount; The second display step displays a second display screen for displaying a second graphic representing the second control amount; The playback step displays the first graphics on the first display screen in a predetermined order from a predetermined start time to an end time based on time information obtained with the first control amount, and displays the second graphics on the second display screen in synchronization with the display of the first graphics based on time information obtained with the second control amount; and The third display step displays a list on a third display screen, the list arranging the first control amounts obtained in the first control amount obtaining step and the second control amounts obtained in the second control amount obtaining step in time series, and displays a specific first control amount included in the list and a specific second control amount included in the list in a display form different from other first control amounts and second control amounts, the specific first control amount being a first control amount whose time indicated by the time information obtained with the first control amount is closest to a playback time between the start time and the end time at which the first graphics are displayed in the playback step, the specific second control amount being a second control amount whose time indicated by the time information obtained with the second control amount is closest to the playback time.

Images