JP2017094458A - Robot moving locus drawing apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To suppress deviation between the actual moving locus of a robot and a moving locus to be drawn while suppressing an increase in processing load.SOLUTION: A drawing apparatus 50 that draws the moving locus of a robot 20 at a drawing period longer than a control period on a display unit 51 on the basis of a signal from a controller 30 that controls the robot 20 at the prescribed control period acquires information indicating the position of the robot 20 at a predetermined point at each control period from the controller 30, determines, on the basis of the acquired information, whether the drawing period includes an extreme value point at which at least one component at the position on a coordinate system takes an extreme value with respect to time, when it is determined that the extreme value point is not included, draws a moving locus connecting the position during the previous drawing period and the position during the current drawing period on the display unit 51, and when it is determined that the extreme value point is included, a moving locus for connection from the position during the previous drawing period to the position during the current drawing period closer to the extreme value point on the display unit 51.SELECTED DRAWING: Figure 1

Description

  The present invention relates to an apparatus for drawing a movement locus of a robot on a display unit.

  2. Description of the Related Art Conventionally, there is a technique in which a first predetermined number of teaching target points are acquired from teaching target points, and a movement locus from the initial position coordinates of the robot to the acquired last teaching target point is drawn on a display unit (Patent Document). 1).

Japanese Patent No. 5375436

  By the way, in order to accurately draw the movement trajectory of the robot, it is desirable to make the drawing cycle for drawing a line connecting the drawing points as short as possible. However, due to the problem of the processing load for drawing the movement trajectory, it is common to draw the movement trajectory with a drawing cycle much longer than the control cycle of the robot. For this reason, the distance between the drawing points is considerably long, and the deviation between the actual movement locus of the robot and the drawn movement locus is large.

  The present invention has been made in view of such circumstances, and the main purpose thereof is to suppress the shift between the actual movement locus of the robot and the drawn movement locus while suppressing an increase in the processing load for drawing the movement locus. It is an object of the present invention to provide a robot movement trajectory drawing apparatus that can be suppressed.

  The present invention employs the following means in order to solve the above problems.

  The first means is a drawing apparatus that draws the movement locus of the robot on the display unit at a drawing cycle longer than the control cycle based on a signal from a control unit that controls the robot at a predetermined control cycle. An acquisition unit that acquires information representing the position of the predetermined point of the robot in each control cycle from the control unit, and at least one of the positions in the coordinate system with respect to time based on the information acquired by the acquisition unit A determination unit that determines whether or not an extreme point in which one component is an extreme value is included in the drawing cycle; and when the determination unit determines that the extreme point is not included, the previous drawing cycle The movement locus connecting the position in the current drawing cycle and the position in the current drawing cycle is drawn on the display unit, and when the determination unit determines that the extreme point is included, the position in the previous drawing cycle Characterized in that it and a drawing unit for drawing the movement locus that connects to the position on the display unit in the current drawing periods displaced in al the extreme point.

  According to the above configuration, based on a signal from the control unit that controls the robot at a predetermined control cycle, the movement trajectory of the robot that connects the drawing point and the drawing point at a drawing cycle longer than the control cycle by the drawing device is displayed on the display unit. Drawn on.

  Here, the information indicating the position of the predetermined point of the robot in each control cycle is acquired from the control unit by the acquisition unit. Then, based on the information acquired by the acquisition unit, the determination unit determines whether or not the drawing cycle includes an extreme point where at least one component of the position in the coordinate system with respect to time is an extreme value. Is done. At the extreme point, the direction of movement of the predetermined point is reversed with respect to at least one component of the coordinate system (for example, the x component of the orthogonal coordinate system), so that the movement locus changes greatly. Therefore, when an extreme point is included in the drawing cycle, the position of the predetermined point in the previous drawing cycle (hereinafter referred to as “previous position”) and the position of the predetermined point in the current drawing cycle (hereinafter referred to as “current position”). ) Is drawn, the difference between the actual movement locus of the robot and the drawn movement locus tends to increase.

  When the determination unit determines that the extreme point is not included, a movement trajectory connecting the previous position and the current position is drawn on the display unit. For this reason, when the direction in which the predetermined point moves is not reversed and the actual movement locus and the drawn movement locus are difficult to shift, the processing load for drawing the movement locus can be reduced.

  On the other hand, when the determination unit determines that an extreme point is included, a movement locus connecting from the previous position to the extreme point is drawn on the display unit. The approach to the extreme point includes not only passing through the extreme point from the previous position and connecting to the current position but also passing through a point near the extreme point from the previous position and connecting to the current position. For this reason, if the direction in which the predetermined point moves is reversed and the actual movement locus is likely to deviate from the drawn movement locus, the movement locus is drawn so as to approach the extreme point between the previous position and the current position. Is done. Therefore, it is possible to suppress a deviation between the actual movement locus of the robot and the drawn movement locus. Furthermore, since only the extreme point is between the previous position and the current position, an increase in processing load for drawing the movement trajectory can be suppressed.

  In the second means, the drawing unit passes through the position in the control cycle in which the position is closest to the extreme point within the drawing cycle when the determination unit determines that the extreme point is included. The position is set to the position, and the movement trajectory connecting the position from the position in the previous drawing cycle to the position in the current drawing cycle is drawn on the display unit.

  The timing at which the position of the predetermined point of the robot becomes an extreme value point may deviate from the position acquisition timing in the control cycle. In this case, the position calculated based on the information indicating the position of the predetermined point and the extreme value point are shifted.

  In this regard, according to the above configuration, when the determination unit determines that an extreme point is included, the position in the control cycle in which the position is closest to the extreme point within the drawing cycle is set as the passing position. Then, a movement locus connecting from the previous position to the current position through the passing position is drawn on the display unit. Therefore, even when the position calculated based on the information indicating the position of the predetermined point and the extreme value point deviate from each other, it is possible to draw a movement trajectory connecting from the previous position to the current position by approaching the extreme value point. .

  In the third means, the determination unit reverses the sign of at least one component of the speed at which the position moves in the coordinate system within the drawing cycle based on the information acquired by the acquisition unit. Then, it is determined that the extreme point is included in the drawing cycle.

  At an extreme point where at least one component of the position in the coordinate system becomes extreme with respect to time, the sign of at least one component of the speed at which the position moves in the coordinate system is inverted. Therefore, it can be easily determined whether or not an extreme point is included in the drawing cycle by determining that the extreme point is included when the sign of at least one component of the velocity is inverted within the drawing cycle. .

  Specifically, as in the fourth means, the determination unit uses the position in the previous drawing cycle, the position in the previous drawing cycle, and the position in the current drawing cycle in the coordinate system. A configuration in which each component of acceleration at which the position moves is calculated, and it is determined whether or not the sign of at least one component of the velocity is reversed within the next drawing cycle by regarding each component of the acceleration as being constant. Can be adopted.

  Specifically, as in the fifth means, when the drawing unit determines that the extremum point is included by the determination unit, the position becomes the extreme point in the drawing cycle. The position in the closest control cycle is set as a passing position, and the determination unit determines whether the position in the coordinate system is based on the position in the previous drawing cycle, the passing position, and the position in the current drawing cycle. A configuration is adopted in which each component of the moving acceleration is calculated, and it is determined whether or not the sign of at least one component of the velocity is reversed within the next drawing cycle, assuming that each component of the acceleration is constant. be able to.

  In the sixth means, the control cycle is 8 ms and the drawing cycle is 200 ms.

  According to the above configuration, since the robot control cycle is 8 ms and the movement trajectory drawing cycle is 200 ms, the processing load is greatly increased as compared with the configuration in which the movement trajectory is drawn at a drawing cycle of 8 ms equal to the control cycle. Can be made smaller.

Perspective view of robot system Display that displays robots and movement trajectories using conventional technology Flowchart showing the procedure for drawing a moving locus Plan view showing movement trajectory in right angle operation Plan view showing movement trajectory in acute angle operation Plan view showing movement trajectory in obtuse angle operation The figure which shows the evaluation result of the shift | offset | difference of the movement locus in each operation | movement

  Hereinafter, an embodiment will be described with reference to the drawings. FIG. 1 is a perspective view of the robot system 10. The robot system 10 includes a robot 20, a controller 30, a teaching pendant 40, a personal computer (personal computer) 50, and the like. The robot 20 is a robot having an arbitrary configuration, for example, for assembling parts or for inspecting parts. A teaching pendant 40 and a personal computer 50 are connected to the controller 30 as peripheral devices. The personal computer 50 is connected as necessary, and does not need to be always connected.

  The robot 20 is configured as a 6-axis vertical articulated robot, for example. The robot 20 has an arm 21 in which each axis is driven by a driving force from a servo motor or the like that is an actuator. The arm 21 has an end effector 22 at the tip. For example, when parts are transported or assembled by the robot 20, a hand for holding these parts is used as the end effector 22. For example, when a part 20 is inspected by the robot 20, a camera that captures a target part is used as the end effector 22.

  Thus, the end effector 22 can be arbitrarily selected according to the process of applying the robot 20. Between the servo motor and the end effector 22 of the arm 21, a driving force transmission mechanism such as a speed reduction mechanism and a link (not shown) is provided. Thereby, the end effector 22 provided at the tip of the arm 21 is driven by the driving force from the servo motor. The robot 20 and the controller 30 are connected by a connection cable 25. Thus, the servo motor that drives each axis of the robot 20 and the end effector 22 that performs the work are controlled by the controller 30. The reference point of the end effector 22 corresponds to a predetermined point of the robot 20.

  The teaching pendant 40 (touch panel type input device) is formed in, for example, a thin rectangular parallelepiped shape, for example, so that the user can carry it or carry it in his hand. The teaching pendant 40 has a display unit 41 made of, for example, a liquid crystal display at the center of the surface portion. Various screens are displayed on the display unit 41. The display unit 41 is configured with a touch panel. The teaching pendant 40 is provided with various key switches 42 around the display unit 41, and the user performs various input operations using the key switches 42 and the touch panel.

  The teaching pendant 40 is connected to the controller 30 via the cable 35 and executes high-speed data transfer with the controller 30 via the communication interface. Information such as operation signals input by the key switch 42 and the touch operation is transmitted from the teaching pendant 40 to the controller 30. Further, the controller 30 supplies driving power to the teaching pendant 40 together with a control signal and a display signal.

  The user can execute various functions such as operation and setting of the robot 20 using the teaching pendant 40 described above. For example, by operating the key switch 42 or the like, it is possible to call a control program stored in advance to start the robot 20 or set various parameters. Various teaching operations can also be executed by operating the robot 20 by manual operation. A desired screen such as a menu screen, a setting input screen, a status display screen, or the like is displayed on the display unit 41 as necessary.

  The personal computer 50 (corresponding to a drawing device) is, for example, a general-purpose notebook personal computer. The user can create a program describing the operation procedure of the robot 20 according to the application by executing the programming software. The personal computer 50 is connected to the controller 30 via the cable 45 and executes high-speed data transfer with the controller 30 via the communication interface. The created program is transferred from the personal computer 50 to the controller 30. In the present embodiment, the personal computer 50 draws the movement locus of the robot 20 based on this program on the display 51 (corresponding to a display unit).

  The controller 30 (corresponding to a control unit) includes a storage device (not shown) and can store a plurality of programs transferred from the personal computer 50. The controller 30 has an actual operation control function for automatically controlling the operation of the robot 20 by executing a program stored in the storage device. Further, the controller 30 creates a control log indicating the control state of the robot 20 when executing the program. When the personal computer 50 draws the movement locus of the robot 20, this control log is transmitted from the controller 30 to the personal computer 50. The control log includes angle data and the like of each axis of the robot 20.

  The user selects one program from the programs stored in advance in the controller 30 by operating the key switch 42, for example, using the teaching pendant 40, and performs automatic control based on the program. It is possible to start or display an operation based on the program on the screen. In this case, the teaching pendant 40 transmits a selection command for selecting a predetermined program, an actual operation start command for instructing execution of actual operation control, and the like to the controller 30.

  FIG. 2 shows a display 51 that displays the robot 20 and the movement trajectory A according to the prior art. The control cycle in which the controller 30 controls the robot 20 is 8 ms. On the other hand, in the prior art, the drawing cycle in which the personal computer 50 draws the movement locus of the reference point of the end effector 22 of the robot 20 on the display 51 is 20 ms. In order to accurately draw the movement locus A of the reference point, it is desirable to make the drawing cycle as short as possible, for example, to make the drawing cycle equal to 8 ms. However, due to the problem of the processing load for the personal computer 50 to draw the movement locus A, the movement locus A is drawn at a drawing cycle 20 ms longer than the control cycle 8 ms of the robot 20.

  Here, as shown by a broken line, the actual movement trajectory of the reference point may include an extreme point P2, which is a point at which at least one component (coordinate) of the position of the reference point becomes an extreme value with respect to time. is there. In the figure, the x component (x coordinate) of the position at the extreme value point P2 becomes a local maximum value with the passage of time with reference to the orthogonal coordinate system of xyz. When the position of the reference point in the drawing cycle immediately before the extreme value point P2 is the point P1, and the position of the reference point in the drawing cycle immediately after the extreme value point P2 is the point P3, the point P1 is the movement locus A of the robot 20. And a straight line connecting point P2 is drawn. For this reason, this inventor discovered that the shift | offset | difference of the actual movement locus | trajectory shown with a broken line and the drawn movement locus | trajectory A shown with a continuous line becomes large. That is, at the extreme value point, the direction of movement of the reference point is reversed with respect to at least one component of the coordinate system, so that the change of the movement locus becomes large. In the figure, at the extreme point P2, the direction in which the reference point moves is reversed with respect to the x component of the xyz coordinate system.

  Therefore, in the present embodiment, it is determined whether or not an extreme point is included in the drawing cycle. When it is determined that the extreme point is included, the extreme point is shifted from the position of the reference point in the previous drawing cycle. Thus, the movement locus connected to the position of the reference point in the current drawing cycle is drawn on the display 51. In this figure, when it is determined that the extremum point P2 is included in the drawing cycle for drawing the movement trajectory from the point P1 to the point P3, the movement trajectory connecting the point P1 to the point P3 from the point P1. Draw.

  In addition, the timing at which the position of the reference point of the robot 20 becomes the extreme point P2 may deviate from the position acquisition timing in the control cycle. In this case, the position calculated based on the information indicating the position of the reference point and the extreme value point P2 are shifted. Therefore, when it is determined that the extreme point P2 is included in the drawing cycle, the position of the reference point in the control cycle in which the position of the reference point is closest to the extreme point P2 in the drawing cycle is set as the passing position. Then, a movement trajectory passing through the passing position from the previous position and connecting to the current position is drawn on the display 51.

  FIG. 3 is a flowchart showing a processing procedure for drawing a movement trajectory. This series of processing is repeatedly executed by the personal computer 50 at a drawing cycle of 20 ms.

  First, a control log in each control cycle within the drawing cycle is acquired from the controller 30 (S11). Specifically, the angle data of each axis of the robot 20 is received by communication with the controller 30.

  Subsequently, it is determined whether or not the extreme point flag is T (True) (S12). As will be described later, the extreme point flag is set to T (True) when the extreme point is included in the drawing cycle from the previous drawing to the current drawing, and F (False) when the extreme point is not included. ).

  In the above determination, when it is determined that the extreme point flag is T (S12: YES), the passing position is set based on the extreme point time (S13). As will be described later, when it is determined that the extreme point is included in the drawing cycle, the extreme point time, which is the time when the movement locus of the reference point of the end effector 22 becomes the extreme point, is calculated. For this reason, the position of the reference point of the end effector 22 is calculated using the control log at the time closest to the extreme point time among the control logs in each control cycle within the drawing cycle. Specifically, the position of the reference point is calculated from the angle of each axis of the robot 20, and the calculated position of the reference point is set as the passing position.

  Subsequently, a straight line connecting the position of the reference point (hereinafter referred to as “previous position”) in the previous drawing cycle and the passing position is drawn as a movement locus (S14).

  On the other hand, if it is determined in S12 that the extreme point flag is F (S12: NO), the passing position is set (S15) and the straight line connecting the previous position and the passing position is drawn (S14). Absent.

  Subsequently, the position of the reference point (hereinafter referred to as “current position”) in the current drawing cycle is calculated (S15). Specifically, the position of the reference point of the end effector 22 is calculated using the control log of the last control cycle among the control logs in each control cycle within the drawing cycle.

  Subsequently, a straight line connecting the positions of the last two reference points is drawn as a movement locus (S16). Specifically, if the passing position is set, a straight line connecting the passing position and the current position is drawn. On the other hand, if the passing position is not set, a straight line connecting the previous position and the current position is drawn. In the process in the first drawing cycle, since there is no passing position and no previous position, this process is not performed.

  Subsequently, each component of acceleration at which the reference point moves is calculated from the positions of the last three reference points (S17). Specifically, if a passing position is set, each component of acceleration at which the reference point moves is calculated from the previous position, the passing position, and the current position. For example, the first speed is calculated from the previous position, the passing position, and the time between them, and the second speed is calculated from the passing position, the current position, and the time between them. Then, acceleration is calculated from the first speed and the second speed. This is performed for each of the x component, the y component, and the z component, and the x component ax, the y component ay, and the z component az of the acceleration are lost. On the other hand, if the passing position is not set, the components ax, ay, and az of the acceleration in which the reference point moves are calculated in the same manner from the previous position, the previous position, and the current position. Note that when the positions of the last three reference points do not exist, this process is not performed, for example, in the process in the first drawing cycle.

  Subsequently, it is determined whether or not the sign of at least one component of the reference point speed is reversed within the next control cycle (S18). Specifically, assuming that the acceleration at the reference position is constant at the calculated acceleration, the sign of the reference point speed in the current control cycle and the sign of the reference point speed in the next control cycle are Determine if they are different. This determination is performed for each of the x component, the y component, and the z component.

  In the above determination, when it is determined that at least one sign of the x component vx, the y component vy, and the z component vz of the velocity v is reversed (S18: YES), the extreme point flag is set to T (S19). Then, an extreme point time, which is a time when the movement locus of the reference point becomes an extreme point, is calculated (S20). Specifically, the time when any of the x component vx, the y component vy, and the z component vz of the velocity v becomes 0 is calculated as the extreme point time.

  On the other hand, if it is determined in S18 that none of the signs of the x component vx, y component vy, and z component vz of the speed v is reversed (S18: NO), the extreme point flag is set to F (S21). .

  Thereafter, this series of processing is temporarily terminated (END). In addition, the process of S11 corresponds to the process as an acquisition part, the process of S12-S16 corresponds to the process as a drawing part, and the process of S17-S19 and S21 corresponds to the process as a determination part.

  FIG. 4 is a plan view showing a movement locus in which the reference point of the end effector 22 of the robot 20 is moved at a right angle. Similarly, FIG. 5 is a plan view showing a movement locus in an acute angle operation, and FIG. 6 is a plan view showing a movement locus in an obtuse angle operation. 4 to 6, the z coordinate (z component) of the reference point is fixed at a predetermined value.

  FIG. 7 is a diagram showing the evaluation result of the shift of the movement trajectory in each operation of FIGS. 4 to 6 in comparison with the prior art. Here, the correlation coefficient is calculated from the actual position of the reference point in each control cycle and the position of the reference point corresponding to each control cycle on the drawn movement trajectory. The correlation coefficient was calculated for each of the x coordinate (x component) and the y coordinate (y component) of the reference point. The correlation coefficient indicates that the closer to 1, the higher the correlation. @E is a mode for moving to the next target position after the angle of each axis of the robot 20 reaches the target angle when moving from the current position to the target position. @P is a mode in which, when moving from the current position to the target position, if the angle of each axis of the robot 20 starts decelerating, the movement to the next target position is started along with the movement to the current target position. is there.

  As is clear from these evaluation results, in this embodiment, the correlation coefficient is close to 1 in any operation and mode as compared with the prior art. In particular, in the y-coordinate of the acute angle operation mode @E, the reduction of the deviation is remarkable. In this case, as shown in FIG. 5, since each target position is an extreme point with respect to the y coordinate, it is considered that the effect of the present embodiment in which the previous position is approached to the extreme point to connect to the current position is enhanced. It is done.

  The embodiment described in detail above has the following advantages.

  When it is determined that the extreme point is not included in the drawing cycle, the movement locus connecting the previous position and the current position is drawn on the display 51. For this reason, when the direction in which the reference point moves is not reversed and the actual movement locus and the drawn movement locus are difficult to shift, the processing load for the personal computer 50 to draw the movement locus can be reduced.

  When it is determined that the extremum point is included in the drawing cycle, a movement trajectory connecting from the previous position to the current position from the previous position is drawn on the display 51. For this reason, if the direction in which the reference point moves is reversed and the actual movement locus and the drawn movement locus are likely to deviate, the movement locus is drawn so as to approach the extreme point between the previous position and the current position. Is done. Accordingly, it is possible to suppress a deviation between the actual movement locus of the robot 20 and the drawn movement locus. Furthermore, since only the extreme point is between the previous position and the current position, an increase in processing load for the personal computer 50 to draw the movement trajectory can be suppressed.

  When it is determined that the extreme point is included in the drawing cycle, the position of the reference point in the control cycle in which the position of the reference point is closest to the extreme point in the drawing cycle is set as the passing position. Then, a movement trajectory connecting from the previous position to the current position through the passing position is drawn on the display 51. Therefore, even when the position calculated based on the information indicating the position of the reference point and the extreme value point deviate from each other, it is possible to draw a movement trajectory connecting the extreme value point from the previous position to the current position. .

  At the extreme point where at least one component of the reference point position in the xyz coordinate system becomes an extreme value with respect to time, the sign of at least one component of the velocity v at which the reference point position moves in the xyz coordinate system is inverted. To do. Therefore, it is possible to easily determine whether or not an extreme point is included in the drawing cycle by determining that the extreme point is included when the sign of at least one component of the velocity v is reversed within the drawing cycle. it can.

  -Since the control cycle of the robot 20 is 8 ms and the drawing cycle of the moving track is 200 ms, the processing load of the personal computer 50 is greatly increased compared to the configuration in which the moving track is drawn with a drawing cycle of 8 ms equal to the control cycle. Can be small.

  In addition, the said embodiment can also be changed and implemented as follows. About the same member as the said embodiment, description is abbreviate | omitted by attaching | subjecting the same code | symbol.

  The control cycle of the robot 20 is not limited to 8 ms, and the drawing cycle of the movement locus is not limited to 200 ms. For example, the control cycle of the robot 20 may be 16 ms, and the drawing cycle of the movement locus may be 400 ms. In short, what is necessary is just to draw the movement locus of the robot 20 on the display 51 with a drawing cycle longer than the control cycle of the robot 20.

  The position of the extreme point between the previous position and the current position may be calculated by interpolating from control logs corresponding to before and after the extreme point. Then, the calculated position of the extreme value point may be set to a passing position between the previous position and the current position. According to such a configuration, it is possible to further suppress the deviation between the actual movement locus and the drawn movement locus.

  The line connecting the previous position, the passing position, and the current position is not limited to a straight line, and may be a curve based on an approximate curve that approximates the shape of the movement locus up to the previous position.

  The coordinate system serving as a reference for the robot 20 is not limited to the xyz orthogonal coordinate system, and may be a cylindrical coordinate system or the like.

  The drawing apparatus is not limited to the personal computer 50, and may be configured by the controller 30 or the teaching pendant 40. Further, the display unit is not limited to the display 51 of the personal computer 50 and may be configured by the display unit 41 of the teaching pendant 40.

  -As a robot, not only a vertical articulated robot but a horizontal articulated robot can also be adopted.

  DESCRIPTION OF SYMBOLS 20 ... Robot, 22 ... End effector, 30 ... Controller (control part), 41 ... Display part, 50 personal computer (drawing apparatus), 51 ... Display (display part).

Claims (6)

A drawing apparatus that draws a movement locus of the robot on a display unit at a drawing cycle longer than the control cycle based on a signal from a control unit that controls the robot at a predetermined control cycle,
An acquisition unit that acquires information representing the position of the predetermined point of the robot in each control cycle from the control unit;
Determination to determine whether or not the drawing cycle includes an extreme point where at least one component of the position in the coordinate system with respect to time is an extreme value based on the information acquired by the acquisition unit And
When the determination unit determines that the extreme point is not included, the movement locus connecting the position in the previous drawing cycle and the position in the current drawing cycle is drawn on the display unit, and the determination unit A drawing unit that draws on the display unit the movement trajectory connecting from the position in the previous drawing cycle to the position in the current drawing cycle from the position in the previous drawing cycle When,
A robot movement trajectory drawing apparatus comprising:   When the determination unit determines that the extreme point is included by the determination unit, the drawing unit sets the position in the control cycle in which the position is closest to the extreme point in the drawing cycle as a passing position, The robot movement locus drawing apparatus according to claim 1, wherein the movement locus is drawn on the display unit from the position in the drawing cycle to the position in the current drawing cycle through the passing position.   Based on the information acquired by the acquisition unit, the determination unit includes the at least one component of the velocity at which the position moves in the coordinate system within the drawing cycle. The robot movement trajectory drawing apparatus according to claim 1, wherein the robot trajectory is determined to include the extreme point.   The determination unit calculates each component of acceleration at which the position moves in the coordinate system based on the position in the previous drawing cycle, the position in the previous drawing cycle, and the position in the current drawing cycle, The robot movement trajectory drawing apparatus according to claim 3, wherein each component of the acceleration is considered to be constant and it is determined whether or not the sign of at least one component of the velocity is reversed within a next drawing cycle. When the drawing unit determines that the extreme point is included by the determination unit, the drawing unit sets the position in the control cycle where the position is closest to the extreme point within the drawing cycle as a passing position;
The determination unit calculates each component of acceleration at which the position moves in the coordinate system based on the position in the previous drawing cycle, the passing position, and the position in the current drawing cycle, The robot movement trajectory drawing apparatus according to claim 3, wherein the component is considered to be constant and it is determined whether or not the sign of at least one component of the velocity is reversed within a next drawing cycle.   The robot movement trajectory drawing apparatus according to claim 1, wherein the control cycle is 8 ms and the drawing cycle is 200 ms.