JP2018008343A - Part pickup method and part supply device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To improve pickup efficiency of parts in a part pickup method and a part supply device.SOLUTION: The present invention relates to a method of making a robot hand 16 pick up one part 40 using am image obtained by photographing a plurality of parts 40 placed on a movable tray 11. A proximity area 33 including a first area 31 corresponding to an outer shape of the part 40 and a second area 32 corresponding to a grip margin of the robot hand 16 is set for each individual part 40 in the image. When there is an isolated part 41 in which the proximity area 33 is separated from the first area 31 of another part, the isolated part 41 is picked up by the robot hand 16. When there is no isolated part 41, a candidate part 42 in which the proximity area 33 overlaps with the first area 31 of a single other component is extracted. Further, a movement distance and a movement direction of the candidate part 42 which eliminate the overlapping of the candidate part 42 and the other part are calculated, and the operation of the movable tray 11 is controlled based on the movement distance and the movement direction.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a method and an apparatus for picking up individual parts with a robot hand using captured images of a plurality of parts placed on a movable tray.

  2. Description of the Related Art Conventionally, there is known a component supply apparatus that individually picks up components stacked on a tray with a robot hand. That is, one part is automatically taken out from a plurality of parts whose positions and orientations are not arranged, and the parts are assembled, aligned, inspected, transferred to the next process, and the like. A camera connected to the image processing apparatus is provided above the tray, and the position of each component and the overlapping state with other components are grasped based on the captured image.

  Examples of parts to be picked up by the robot hand include parts that are not in contact with other parts on the tray (or parts that are hardly in contact). However, there is a case where there is no part suitable for the pickup target depending on the part stacking state. In view of this, a technique has been proposed in which the tray on which the components are placed is vibrated to loosen the loosely stacked state and the components to be picked up are isolated. There has also been proposed a technique for changing the unstacked state of components by causing protrusions to protrude from the bottom surface of the tray using an air cylinder or an electric cylinder (see, for example, Patent Documents 1 and 2).

Japanese Patent Laid-Open No. 11-300670 JP 2012-183616

  However, in the conventional technique, it is impossible to predict how the parts are unpacked, and it is difficult to isolate the parts in a short time. In other words, the vibrations and shocks applied to the trays act to increase the degree of cluttering of the stacked parts (the degree of dispersion), but depending on the shape and arrangement of the parts, one overlapping state can be canceled and new Can generate an overlapping state. Therefore, there is a problem that it is difficult to quickly and surely appear parts suitable for the pickup target, and it is difficult to improve pickup efficiency.

  In one aspect, the object is to improve the pick-up efficiency of components.

  In one aspect, the component pickup method is a component pickup method in which one of the components is picked up by a robot hand using an image obtained by photographing a plurality of components placed on a movable tray. First, for each individual part in the image, a proximity area including a first area corresponding to the outer shape of the part and a second area corresponding to a gripping allowance of the robot hand is set. When there is an isolated part in which the proximity area is separated from the first area of other parts, the robot hand is caused to pick up the isolated part. On the other hand, if there is no isolated part, candidate parts whose adjacent area overlaps the first area of a single other part are extracted. Further, the moving distance and moving direction of the candidate part that eliminate the overlap between the candidate part and another part are calculated, and the operation of the movable tray is controlled based on the moving distance and the moving direction.

  The pickup efficiency of parts can be improved.

It is a figure which illustrates the system in which a components supply apparatus is included. It is a figure which illustrates the hardware constitutions of a components supply apparatus (control apparatus). It is a figure which illustrates the software structure of a components supply apparatus (control apparatus). (A) is a schematic diagram for demonstrating a 1st area | region, a 2nd area | region, and a proximity | contact area | region, (B) is a perspective view which illustrates the nail | claw of a robot hand. (A)-(D) are the schematic diagrams for demonstrating the analysis method of the arrangement state of components. (A)-(D) are the schematic diagrams for demonstrating the calculation method of the moving distance and moving direction in which the overlapping of components is eliminated. It is a schematic diagram for demonstrating the relationship between the inclination of a movable tray, and the movement amount of components. It is a schematic diagram for demonstrating the movement amount of the components on a movable tray. It is a graph for demonstrating the operating state of an actuator. It is a flowchart for demonstrating a component pick-up method.

  With reference to the drawings, a component pickup method and a component supply apparatus as embodiments will be described. However, the embodiment described below is merely an example, and there is no intention of excluding various modifications and technical applications that are not explicitly described in the embodiment. In other words, the present embodiment can be implemented with various modifications (for example, by combining the embodiments and modifications) without departing from the spirit of the present embodiment.

[1. System overview]
As shown in FIG. 1, the component pick-up method and component supply apparatus of the present embodiment captures a plurality of components 40 (workpieces) placed on the movable tray 11 with the camera 15 and uses the captured images to capture the components 40. This is applied to the component supply system 10 that causes the robot hand 16 to pick up one of the above. The movable tray 11 is a workpiece supply base having a mounting surface 12 on which the components 40 are stacked and an actuator 13 for changing the inclination angle of the mounting surface 12. The inclination angle of the mounting surface 12 is an actuator. 13 can be changed freely. Further, a peripheral wall portion 14 for preventing the component 40 from sliding down is erected along the outer edge of the placement surface 12.

  Information on the image captured by the camera 15 is transmitted to the control device 20 as a component supply device, and the contour shape, position, overlapping state, etc. of each component 40 are grasped by a known image analysis process. The operating states of the actuator 13 and the robot hand 16 are also controlled and managed by the control device 20 in an integrated manner. Although the specific shape and weight of the component 40 are arbitrary, in this embodiment, the component 40 having a flat shape (a three-dimensional shape having a smaller dimension in the thickness direction compared to the height direction and the width direction) is taken as an example. explain.

  The actuator 13 supports the movable tray 11 so as to be tiltable with respect to the ground surface or the floor surface, and is, for example, a telescopic electromagnetic cylinder (solenoid actuator). The number of actuators 13 is at least two or more (for example, a structure in which the movable tray 11 is supported by two electromagnetic cylinders and one pin junction), and preferably three or four (for example, movable) The tray 11 is supported by three or four electromagnetic cylinders). When the mounting surface 12 has a quadrangular shape when viewed from above, the actuator 13 may be connected to the four corners of the mounting surface 12 or the central portion of the four sides via a universal joint. The expansion / contraction direction of the actuator 13 is a direction including at least a vertical component (a non-horizontal direction). By adjusting the amount of expansion / contraction of each actuator 13 simultaneously, the inclination angle and height of the mounting surface 12 can be set arbitrarily. Note that a damping spring, a gel-like vibration isolating rubber, or the like may be disposed below the mounting surface 12 to suppress or alleviate unintended vibrations that may occur with the expansion / contraction operation of the actuator 13.

  The acceleration of the movable tray 11 when the tilt angle is changed by the actuator 13 is set to an acceleration (acceleration equal to or higher than the gravitational acceleration) to the extent that the component 40 on the placement surface 12 instantaneously floats in the air. However, an excessive acceleration that causes all the parts 40 to float in the air is not necessary, and it is sufficient to provide at least an acceleration that can float a desired part 40 (for example, a candidate part 42 described later). By abruptly inclining the mounting surface 12 in a state where the components 40 are stacked from the horizontal state, the component 40 on the mounting surface 12 temporarily floats, and then faces the inclined mounting surface 12. Fall naturally. The displacement amount (movement amount) of the component 40 before and after the natural fall increases in proportion to the distance from the tilt axis of the mounting surface 12.

  The displacement direction of the component 40 due to natural fall is a direction perpendicular to the tilting axis of the mounting surface 12 when viewed from above, and this is the direction in which the mounting surface 12 is inclined (slowly placed on the inclined mounting surface 12). The direction in which the ball is moved). That is, the component 40 on the mounting surface 12 moves relatively in the tilt direction in the process of natural fall, and the amount of displacement increases as the position is farther from the tilt axis. Accordingly, the components 40 move so as to be separated from each other in the tilt direction of the mounting surface 12, and the distance in the tilt direction between the components 40 (for example, the gap size between the components 40) increases. .

  The value of acceleration when the movable tray 11 is tilted becomes smaller as the position is closer to the tilt axis, and becomes larger as the position is farther from the tilt axis. Accordingly, when it is desired to move the entire movable tray 11 at an acceleration equal to or higher than the gravitational acceleration, all the actuators 13 may be operated so that the tilt axis is positioned outside the mounting surface 12 in a top view. . Further, when the mounting surface 12 is translated vertically downward, the acceleration value is uniform throughout the movable tray 11. Therefore, control may be performed such that the placement surface 12 is inclined after the entire movable tray 11 is rapidly translated downward.

  The camera 15 is a photographing means incorporating a known image sensor, and is, for example, a CCD (Charge-Coupled Device) camera or a CMOS (Complementary Metal Oxide Semiconductor) camera. Here, the overall arrangement state of the parts 40 stacked in bulk is acquired as image and video data. The viewing angle of the camera 15 is set so that almost the entire mounting surface 12 is included. The number of cameras 15 may be at least one, but a plurality of cameras 15 (for example, stereo cameras) may be used. In this case, the three-dimensional position of the component 40 can be grasped with high accuracy.

  The robot hand 16 is a multi-finger hand type industrial robot having a function of picking up the component 40. Here, “pickup” means an operation of picking up the component 40 with the robot hand 16. For example, this includes an operation of grasping the part 40 between the claws 17 provided on the robot hand 16 and holding it up. The operation of the robot hand 16 of the present embodiment is controlled based on a program for picking up the parts 40 in order of high pickup efficiency. Hereinafter, this program will be referred to as a “part pickup program” and will be described with reference numeral 1.

  In the component pickup program 1 of the present embodiment, the component 40 to be picked up is a component 40 that does not overlap with other components and the claw 17 of the robot hand 16 does not interfere with other components. That is, only the parts 40 for which the gripping allowance of the robot hand 16 is secured are picked up. However, a slight overlap with other parts can be tolerated to some extent as long as the operation of the robot hand 16 is not hindered during pick-up or the quality of the part 40 is not affected.

  In the present specification, among the plurality of components 40 placed on the placement surface 12, those that do not interfere with other components and can be picked up immediately by the robot hand 16 are referred to as “isolated components 41”. The object to be picked up by the robot hand 16 is an isolated component 41. A part 40 that is not an isolated part 41 and that overlaps a single other part (one or more other parts) is referred to as a “candidate part 42”. The candidate component 42 is a component 40 that can become an isolated component 41 if interference with other components overlapping it is eliminated. The component pickup program 1 improves the pickup efficiency of the component 40 by controlling the candidate component 42 to be the isolated component 41 when there is no isolated component 41 while preferentially picking up the isolated component 41. Has function. Note that, in order to pick up the parts 40 that overlap two or more other parts, at least those other parts must be moved, which is not efficient, and therefore the priority order as a pickup target is lowered.

  That is, when an isolated part 41 is found through analysis processing of an image taken by the camera 15, the isolated part 41 is selected as a pickup target. When there are a plurality of isolated parts 41, the plurality of isolated parts 41 are picked up in order in the order in which the moving distance of the robot hand 16 is as short as possible. On the other hand, if there is no isolated component 41, a candidate component 42 is extracted based on the overlapping state of the components 40, and the moving distance and moving direction of the candidate component 42 for eliminating the overlapping state are calculated. . When there is one candidate part 42, the actuator 13 is driven to move the candidate part 42. Further, when there are a plurality of candidate parts 42, which candidate part 42 has the shortest moving distance is examined, and the actuator 13 is driven to move the candidate part 42. At this time, the distance (distance from the peripheral wall part 14) that the candidate part 42 can move is also taken into consideration.

  The inclination direction of the movable tray 11 is controlled so as to coincide with the moving direction of the candidate part 42. In addition, after the candidate part 42 on the placement surface 12 that has temporarily floated freely falls onto the inclined placement surface 12, the actuator 13 is controlled so that the placement surface 12 becomes horizontal again. The transition speed from the inclined state to the horizontal state may be a speed at which each component 40 on the mounting surface 12 is not scattered in the process. Such an operation of the movable tray 11 is repeated until the moving distance of the candidate part 42 is ensured (for example, until the candidate part 42 becomes a pickup target). Note that, as a result of driving the actuator 13, when a part 40 different from the candidate part 42 becomes a new isolated part 41, the isolated part 41 may be preferentially picked up. Alternatively, the movable tray 11 is repeatedly operated until the number of actuations of the actuator 13 corresponding to the movement distance of the candidate part 42 is achieved regardless of whether or not the candidate part 42 is actually an isolated part 41. Also good.

  The overlapping shape between components is handled by approximating the contour shape of each component 40 to a polygon. The moving distance for eliminating interference with other parts can be expressed as the minimum value of the width in the normal direction with reference to each side in the overlapping shape of the polygons. The moving direction is a normal direction that gives the minimum value. For example, when the overlapping shape of two parts is a triangle, there are three directions perpendicular to each side of the triangle. In the present embodiment, when the two parts are separated in each of these three directions, the direction and distance in which the two parts do not overlap with each other with the smallest moving distance are calculated.

  Here, “first region 31, second region 32, proximity region 33” is defined with respect to the determination of the overlapping state of the components 40. The first region 31 is a region set for each component 40 in the image, and is a region corresponding to the outer shape (approximate outer shape) of the component 40. The second area 32 is an area corresponding to the gripping allowance of the robot hand 16 in each component 40. The proximity region 33 is a region including the first region 31 and the second region 32. The determination of the isolated component 41 and the candidate component 42 is determined according to the overlapping state of the first region 31 of the other component and the proximity region 33 of the own component. For example, assuming that there are two parts A and B, when the proximity area 33 of the part A does not overlap the first area 31 of the part B, it is expressed as “part A is separated from the part B”. Further, when the part A does not overlap the first region 31 of all other parts, it is expressed as “the part A is an isolated part 41”. On the other hand, when the proximity area 33 of the part A overlaps the first area 31 of only the part B and does not overlap the first area 31 of other parts, it is expressed as “part A is a candidate part 42”.

[2. hardware]
FIG. 2 is a diagram illustrating a hardware configuration of the control device 20. The control device 20 has a function of causing the robot hand 16 to perform a pick-up operation of the component 40 based on an image photographed by the camera 15 and a function of driving the actuator 13 when there is no component 40 suitable for pick-up. It is a computer (electronic control device) that has it. The control device 20 includes a processor 21 (CPU, central processing unit), a memory 22 (main memory, main storage device), an auxiliary storage device 23, an interface device 24, a recording medium drive 25, and the like. So that they can communicate with each other.

  The processor 21 is a central processing unit that incorporates a control unit (control circuit), an arithmetic unit (arithmetic circuit), a cache memory (register group), and the like. The memory 22 is a storage device that stores a program and working data, and includes, for example, a ROM (Read Only Memory) and a RAM (Random Access Memory). On the other hand, the auxiliary storage device 23 is a memory device that stores data and firmware that are held for a longer time than the memory 22. For example, a nonvolatile memory such as a flash memory or an EEPROM (Electrically Erasable Programmable Read-Only Memory) is used. Included in this. The interface device 24 controls input / output (I / O) between the control device 20 and the outside.

  The recording medium drive 25 is a reading device that reads information recorded and stored in a recording medium 27 (removable medium) such as an optical disk or a semiconductor memory. The program executed by the control device 20 (for example, the component pickup program 1) may be recorded and stored in the memory 22 or may be recorded and stored in the auxiliary storage device 23. Alternatively, the component pickup program 1 may be recorded and stored on the recording medium 27. In this case, the component pickup program 1 written in the recording medium 27 is read into the control device 20 via the recording medium drive 25.

  The control device 20 is connected to the actuator 13 of the movable tray 11, the camera 15, and the robot hand 16. When an output device such as a display or a printer is connected to the control device 20, a captured image may be displayed on these output devices. Alternatively, a CG (Computer Graphics) image of the part 40 whose outer shape is approximated to a polygon is displayed on these output devices, and the user visually checks the overlapping state of the parts 40 and the arrangement state of the isolated parts 41, the candidate parts 42, and the like. You may be able to confirm with

[3. software]
FIG. 3 is a block diagram for explaining the processing contents of the component pickup program 1. The parts pickup program 1 includes a setting unit 2, a pickup unit 3, an extraction unit 4, a calculation unit 5, and a control unit 6. These are the functions of the component pick-up program 1 classified for convenience, and each element may be described as an independent program, or may be described as a composite program having these functions. Good.

The setting unit 2 sets the proximity region 33 as one of the image processes for grasping the overlapping state and position with other components for each component 40 in the image. The proximity area 33 includes a first area 31 and a second area 32.
The first area 31 of the present embodiment is a quadrangle having substantially the same shape as the outer shape of the component 40, and the second area 32 is a quadrilateral connected to both long sides of the first area 31. As shown in FIG. 4A, the vertical dimension of the second area 32 is set to W _{1 which} is the same as the vertical dimension of the first area 31 and the horizontal dimension of the second area 32 is set to W ₂ . Proximity region 33 is a region determined whether the interference with other parts, are rectangle the width of the first region 31 was increased by 2W ₂ minutes.

Each of the vertical dimension W ₁ and the horizontal dimension W ₂ of the second region 32 is set according to the size of the claw 17 of the robot hand 16. For example, as shown in FIG. 4 (B), when the transverse dimension vertical dimension a W ₃ of the pawl 17 is W _4, such that the _{W 1 ≧ W 3, W 2} ≧ W 4, W 1 , W ₂ are set. Such a setting prevents interference between the robot hand 16 and other parts during pick-up.

  The setting unit 2 identifies the position of each component 40 included in the image and assigns an identification number [see FIG. 5 (A)]. The contour shape of each component 40 is extracted (see FIG. 5B), and the first region 31, the second region 32, and the proximity region 33 are set in each component 40 [FIG. )reference〕. The isolated component 41 is recognized based on the first area 31, the second area 32, and the proximity area 33. The identification number is convenient for distinguishing the components 40, and a known allocation method can be used. The recognition method of the isolated component 41 is the same, and a known recognition method can be used. For example, a component 40 in which the proximity region 33 does not overlap the first region 31 of other components is extracted and recognized as an isolated component 41.

  The pickup unit 3 causes the robot hand 16 to pick up the isolated component 41 when the isolated component 41 exists in the image. As shown in FIG. 5D, when there is one isolated component 41, a command for picking up the isolated component 41 by the robot hand 16 is issued. If there are two or more isolated parts 41, the one with the closest distance from the hand of the robot hand 16 is set as the pickup target, and when the pickup operation is completed, the movement distance of the robot hand 16 is as long as possible. A plurality of isolated parts 41 are picked up in order in the order of shortening. The priority order may be determined using a known method.

The extraction unit 4 extracts candidate parts 42 when no isolated parts 41 exist in the image. Here, the component 40 in which the proximity region 33 overlaps the first region 31 of another component and the number of other components overlapping is one is extracted and recognized as the candidate component 42. For example, No. 1, No. 2 and No. 5 in FIG. On the other hand, No. 3 is excluded from the candidate parts 42 because it overlaps the first regions 31 of the two other parts. In addition, the overlapping state regarding the 1st-5th components 40 in FIG. 5 (D) is as follows.

  The calculation unit 5 calculates how much and in what direction the candidate part 42 should be moved in order to eliminate the overlap between the candidate part 42 and other parts. That is, the calculation unit 5 calculates the minimum moving distance and moving direction that can eliminate the overlapping state in the positional relationship between the candidate component 42 and the other components that overlap the candidate component 42. In addition, the calculation unit 5 calculates the separation distance between the peripheral wall portion 14 of the movable tray 11 and the candidate part 42 based on the moving direction.

  The overlapping state of the candidate part 42 and other parts is approximated by a polygon. The moving distance is the minimum value of the width in the normal direction with respect to each side of the polygon, and the normal direction that gives the minimum value is the moving direction. For example, when the overlapping shape is a triangle, three widths based on three sides are calculated, and the smallest one of them is set as the moving direction. Similarly, if the overlapping shape is a quadrangle, the minimum value of the four widths is the moving direction, and if the overlapping shape is a pentagon, the minimum value of the five widths is the moving direction. In addition, the direction of the normal that gives the moving direction is defined as the moving direction.

  These moving distance and moving direction are calculated for each candidate part 42. That is, when there are a plurality of candidate parts 42, the moving distance and moving direction for each candidate part 42 are calculated. The minimum value of these moving distances is the most efficient moving distance and moving direction in order to eliminate the overlapping state. Further, when the movement direction for each candidate part 42 is determined, how far the candidate part 42 is away from the peripheral wall part 14 in the movement direction (how much the candidate part 42 collides with the peripheral wall part 14). Calculated. The separation distance from the peripheral wall portion 14 is calculated based on the shape of the candidate part 42 and the position of the peripheral wall portion 14.

  Here, as shown in FIG. 6A, an explanation will be given by taking an example of the overlapping state of the second and first candidate parts 42 as an example. The calculation unit 5 calculates the shape of the overlapping portion 34 between the second proximity region 33 and the first first region 31. Since the proximity region 33 and the first region 31 are both square, the shape of the overlapping portion 34 (overlapping shape) is a polygon. The calculating unit 5 calculates the moving distance and moving direction of the candidate part 42 from which the overlapping state is eliminated.

  When the overlapping shape is a triangle, the length of a normal (normal line) to each vertex is calculated. The perpendicular length corresponds to the width of the overlapping shape with respect to the side (width in the normal direction). After calculating the perpendicular length for each side, the minimum value thereof becomes the movement distance, and the extending direction of the perpendicular line that gives the minimum value becomes the movement direction of the candidate part 42. Strictly speaking, when one of both end points of the perpendicular belongs to the candidate part 42 and the other belongs to the other part, the direction from one to the other is the moving direction of the candidate part 42.

The example shown in FIG. 6B is a case where the overlapping shape is a triangle surrounded by vertices a, b, and c.
The side ac is a contour line of the proximity region 33 of the candidate part 42, and the side ab and the side bc are contour lines of the first region 31 of another part. Further, it is assumed that the inner angle at the vertex b is a right angle. The perpendicular length from the side ab to the vertex c is equal to the length of the side bc, and the perpendicular length from the side bc to the vertex a is equal to the length of the side ab. Further, the perpendicular length from the side ac to the vertex b is the length of the line segment bd if the foot of the perpendicular from the vertex b is a point d. Since the line segment bd takes the minimum value among these, the length of the line segment bd becomes the moving distance of the candidate part 42. The moving direction is the extending direction of the line segment bd (the direction from the point d to the vertex b).

The example shown in FIG. 6C is a case where the overlapping shape is a quadrangle surrounded by vertices a to d.
Side bc and side cd are contour lines of the proximity region 33 of the candidate part 42, and side ab and side ad are contour lines of the first region 31 of other parts. Further, it is assumed that the inner angles at the vertex a and the vertex c are right angles. The width in the normal direction relative to the side bc is the length of the side cd, and the width in the normal direction relative to the side cd is the length of the line segment ae (the point e is a perpendicular line from the vertex a to the side cd Feet). Similarly, the width in the normal direction with respect to the side ab is the length of the side ad, and the width in the normal direction with respect to the side ad is the length of the line segment cf (the point f is from the vertex c to the side ad Perpendicular to the foot). Among these, the minimum value [the line segment cf in FIG. 6C] is the moving distance of the candidate part 42, and the direction (the direction from the point c to the point f) is the moving direction.

The example shown in FIG. 6D is a case where the overlapping shape is a pentagon surrounded by vertices a to e.
Side bc and side cd are contour lines of the proximity region 33 of the candidate part 42, and side ab, side ae, and side de are contour lines of the first region 31 of other parts. Further, it is assumed that the internal angles of the vertex a, the vertex c, and the vertex e are right angles. The width in the normal direction relative to the side bc is the length of the line segment ef (the point f is a vertical leg from the vertex e to the side bc), and the width in the normal direction relative to the side cd is the line segment ag (The point g is the vertical leg from the vertex a to the side cd). In addition, the width in the normal direction with respect to the side ab is the length of the side ae, and the width in the normal direction with respect to the side de is also the length of the side ae. Further, the width in the normal direction with respect to the side ae is the length of the line segment ch (the point h is a vertical leg from the vertex c to the side ae). Among these, the minimum value (the line segment ch in FIG. 6D) is the moving distance of the candidate part 42, and the direction (the direction from the point c to the point h) is the moving direction.

  The control unit 6 controls the operation of the movable tray 11 to move the candidate component 42 based on the moving distance, moving direction, and separation distance of the candidate component 42 calculated by the calculating unit 5. For example, if there is only one candidate part 42, it is determined which actuator 13 should be reduced and operated at what rate and in what amount to move the candidate part 42 in the moving direction. Is done. In addition, when a sufficient amount of movement cannot be obtained by operating the actuator 13 once, the number of operations of the actuator 13 is also determined. At this time, it is preferable to operate the actuator 13 after confirming that the moving distance of the candidate part 42 is not more than the separation distance from the peripheral wall portion 14. On the other hand, when there are a plurality of candidate parts 42, the candidate part 42 having the shortest moving distance is selected as the movement target. At this time, the movement target may be determined on the condition that the separation distance is equal to or greater than the movement distance.

  A relationship between the moving distance of the candidate part 42 and the operation amount of the actuator 13 will be described. Here, as shown in FIG. 7, it is assumed that actuators 13 </ b> A to 13 </ b> D are provided at the four corners of the mounting surface 12. The operation ratio of the actuators 13A to 13D (for example, the ratio of the reduction amount of the cylinder) is uniquely determined according to the tilt direction. When the inclination direction is the left direction in FIG. 8, the two actuators 13A and 13B may be reduced by the same operation amount. Further, when the inclination direction is the upward direction in FIG. 8, the two actuators 13A and 13C may be reduced by the same operation amount.

Here, if the inclination angle when the mounting surface 12 of the movable tray 11 is abruptly inclined from the horizontal state is θ, the movement amount δ (movement amount with respect to the mounting surface 12) due to the natural fall of the component 40 is inclined. It increases according to the distance from the axis (see FIG. 8). The movement amount δ ₁ at the position where the distance from the tilt axis is L is given by the following expression 1. Similarly, the movement amount δ ₂ at the position where the distance from the tilt axis is L + D is given by the following equation 2. In this manner, the amount of movement of the candidate part 42 can be calculated based on the distance from the inclination axis of the candidate part 42 and the inclination angle. Similarly, the amount of movement of the other part can be calculated based on the distance from the tilt axis and the tilt angle of the other part that overlaps the candidate part 42. When the difference between the former and the latter reaches the moving distance, the overlapping state between the candidate part 42 and other parts is eliminated.

なお、式１中のLを0に限りなく近づけた場合の極限値が0であるのに対し、式２中のLを0に限りなく近づけた場合の極限値は正の値〔(D/cosθ)-D〕をとる。したがって、可動トレイ１１の駆動を繰り返すことで、それぞれの部品４０が互いの隙間を増大させるように移動し、候補部品４２とこれに重なる他部品との距離が増大する。

Note that the limit value when L in Equation 1 approaches 0 as much as possible is 0, whereas the limit value when L in Equation 2 approaches 0 as much as possible is a positive value [(D / cos θ) −D]. Therefore, by repeating the driving of the movable tray 11, each component 40 moves so as to increase the gap between each other, and the distance between the candidate component 42 and another component overlapping therewith increases.

FIG. 9 is a graph for explaining the operating state of the actuator 13. The vertical axis represents the position of the actuator 13 in the height direction. The actuator 13 is controlled to repeat the operation of tilting the mounting surface 12 of the movable tray 11 from the horizontal state at a high speed and then returning it. Times t _{1 to} t ₂ in the graph are periods in which the actuator 13 is rapidly contracted, and are periods in which the component 40 temporarily floats and naturally falls. Times t _{2 to} t ₃ are periods for maintaining the contracted state of the actuator 13, and are standby periods for the component 40 that is naturally falling. Times t _{3 to} t ₄ are periods in which the actuator 13 is slowly extended, and are periods in which the placement surface 12 is returned to the horizontal state again. The change gradient of the position of the actuator 13 is set so as to be smaller between the times t _{3 and} t ₄ than between the times t _{1 and} t ₂ .

  Such an operation is continued until the moving distance of the candidate part 42 is secured. That is, the control unit 6 has a function of controlling the operation of tilting the movable tray 11 in the moving direction at an acceleration larger than the gravitational acceleration and then returning the movable tray 11 to the original, and repeating this control a number of times according to the moving distance. The movement amount of the component 40 per cycle increases as the one-time expansion / contraction amount of the actuator 13 increases. Therefore, it is preferable to set the amount of one expansion / contraction of the actuator 13 in the vicinity of the maximum operation amount.

[4. flowchart]
FIG. 10 is a flowchart for explaining the control procedure of the component pickup program 1. First, a plurality of parts 40 placed on the movable tray 11 are photographed by the camera 15 (step A1). The arrangement state of each component 40 in the image is recognized by the control device 20 (step A2), and it is determined whether or not the component 40 is present in the image (step A3). Here, when there is no part 40 (for example, when all parts 40 have been picked up), this flow ends.

  When the component 40 is present in the image, the first region 31, the second region 32, and the proximity region 33 are set for each component 40 (step A4). Further, it is determined whether or not there is an isolated component 41 (a pickup target) in which the proximity region 33 does not overlap the first region 31 of other components (step A5). Here, when there is an isolated component 41 in the image, a control for picking up the isolated component 41 by the robot hand 16 is performed (step A6). When there are a plurality of isolated parts 41, the one with the shortest distance from the hand of the robot hand 16 is set as the pickup target, and pickup control for all the isolated parts 41 is repeated.

  On the other hand, when there is no isolated component 41 (for example, when all the isolated components 41 are picked up), candidate components 42 that overlap with only one other component are extracted from the image (step A7). The moving distance and moving direction for eliminating the overlapping state of the candidate part 42 are calculated (step A8). Further, the separation distance between each candidate component 42 and the peripheral wall portion 14 is calculated (step A9), the separation distance from the peripheral wall portion 14 is sufficiently larger than the movement distance of the candidate component 42, and the movement distance is The smallest candidate part 42 is selected as a movement target (step A10).

  When the candidate part 42 to be moved is determined, the target operation state (for example, position, operation amount, number of operations, etc.) of the actuator 13 is calculated based on the movement distance, movement direction, and separation distance of the candidate part 42. (Step A11). The moving direction of the candidate part 42 affects the position and number of the actuators 13 to be driven, the ratio of the individual operation amounts, and the like. Further, the moving distance of the candidate part 42 affects the operation amount of each actuator 13. Thereafter, the actuator 13 is controlled so as to rapidly change from the horizontal state to the inclined state (step A12), and is repeated periodically by the number of times corresponding to the moving distance (step A13). In addition, when the candidate part 42 becomes the isolated part 41, it is picked up in the next control cycle.

[5. effect]
(1) In the present embodiment, the first region 31, the second region 32, and the proximity region 33 are set for each component 40 placed on the movable tray 11. Further, the presence or absence of the isolated component 41 is determined based on these areas, and if there is an isolated component 41, it is selected as a pickup target. On the other hand, if there is no isolated part 41, a candidate part 42 in which the proximity area 33 overlaps the first area 31 of a single other part is extracted, and the movement distance that eliminates the overlap between the candidate part 42 and the other part , The moving direction is calculated. By controlling the movable tray 11 based on these moving distances and moving directions, the overlapping state between the candidate part 42 and other parts can be efficiently eliminated, and the pickup efficiency of the part 40 can be improved.

  (2) In this embodiment, the overlapping shape of the candidate part 42 and other parts is approximated by a polygon. Further, the minimum value of the width in the normal direction with respect to each side of the polygon is calculated as the movement distance, and the normal direction that gives the minimum value is calculated as the movement direction. Thereby, the movement amount for making the candidate part 42 into the isolated part 41 can be minimized, and the time taken to eliminate the overlapping state can be shortened. Therefore, the pickup efficiency of the component 40 can be improved.

  (3) In the present embodiment, the operation of tilting the movable tray 11 in the moving direction at an acceleration larger than the gravitational acceleration and then returning it to the original is repeated. By such control, the candidate component 42 can be reliably and easily moved in the moving direction. Further, the amount of movement of the candidate part 42 due to the operation of the movable tray 11 can be accurately predicted and calculated. Thereby, the controllability of the overlapping state can be improved, and the candidate part 42 can be efficiently made into the isolated part 41 in a short time. Therefore, the pickup efficiency of the component 40 can be improved.

(4) In the present embodiment, when there are a plurality of candidate parts 42, the candidate part 42 having the minimum moving distance is selected as the movement target. Thereby, a moving object can be set in an efficient order, and the pickup efficiency of the component 40 can be improved.
(5) In the present embodiment, the separation distance between the peripheral wall portion 14 of the movable tray 11 and the candidate part 42 with respect to the moving direction is calculated. In addition, when setting the movement target, it is a condition that the movement distance of the candidate part 42 is equal to or less than the separation distance. As a result, it is possible to avoid a situation in which the moving object does not collide with the peripheral wall portion 14 and become the isolated component 41. Therefore, the overlapping state of the candidate parts 42 can be more reliably eliminated, and the pickup efficiency of the parts 40 can be improved.

[6. Addendum]
The following additional notes are disclosed regarding the embodiment including the above-described modification.
(Appendix 1)
In a component pick-up method in which a robot hand picks up one of the parts using an image obtained by photographing a plurality of parts placed on a movable tray.
For each of the components in the image, set a proximity region including a first region corresponding to the outer shape of the component and a second region corresponding to the gripping allowance of the robot hand,
When there is an isolated part in which the proximity area is separated from the first area of other parts, the robot hand picks up the isolated part,
When there is no isolated part, extract a candidate part where the proximity area overlaps the first area of a single other part,
Calculate the moving distance and moving direction of the candidate part that eliminates the overlap between the candidate part and other parts,
A component pickup method, comprising: controlling an operation of the movable tray based on the movement distance and the movement direction.

(Appendix 2)
When calculating the movement distance and the movement direction, the overlapping shape of the candidate part and other parts is approximated by a polygon, the width in the normal direction with respect to each side of the polygon is calculated, 2. The component pick-up method according to claim 1, wherein the minimum value of the width is the moving distance, and the normal direction that gives the minimum value is the moving direction.
(Appendix 3)
When controlling the operation of the movable tray, the operation of tilting the movable tray in the moving direction at an acceleration larger than the gravitational acceleration and then returning the movable tray to the original is repeated a number of times according to the moving distance. The method for picking up a component according to appendix 1 or 2.
(Appendix 4)
Supplementary notes 1 to 3, wherein when there are a plurality of candidate parts, the operation of the movable tray is controlled based on the movement distance and the movement direction of the candidate part that minimizes the movement distance. The component pickup method according to any one of the above.
(Appendix 5)
When calculating the moving distance and the moving direction, it is confirmed that a separation distance between the peripheral wall portion of the movable tray and the candidate part with respect to the moving direction is equal to or more than the moving distance. The component pick-up method according to any one of appendices 1 to 4.

(Appendix 6)
In a component supply apparatus for picking up one of the components by a robot hand using an image obtained by photographing a plurality of components placed on a movable tray,
For each of the components in the image, a setting unit that sets a proximity region including a first region corresponding to the outer shape of the component and a second region corresponding to the gripping allowance of the robot hand;
When there is an isolated part in which the proximity area is separated from the first area of other parts, a pickup unit that causes the robot hand to pick up the isolated part;
When there is no isolated part, an extraction unit that extracts a candidate part in which the proximity area overlaps the first area of a single other part;
A calculation unit for calculating a movement distance and a movement direction of the candidate part in which an overlap between the candidate part and another part is eliminated;
A control unit for controlling the operation of the movable tray based on the moving distance and the moving direction;
A component supply device comprising:

(Appendix 7)
The calculation unit approximates an overlapping shape of the candidate part and another part with a polygon, calculates a width in a normal direction with respect to each side of the polygon, and sets the minimum value of the width as the movement distance The component supply apparatus according to appendix 6, wherein the normal direction giving the minimum value is the moving direction.
(Appendix 8)
The appendix 6 or 7, wherein the control unit repeats the operation of tilting the movable tray in the moving direction at an acceleration larger than the gravitational acceleration and then returning the movable tray to the original number of times according to the moving distance. Parts supply equipment.
(Appendix 9)
The control unit controls the operation of the movable tray based on the movement distance and the movement direction of the candidate part that minimizes the movement distance when there are a plurality of the candidate parts. The component supply apparatus according to any one of appendices 6 to 8.
(Appendix 10)
Any one of Supplementary notes 6 to 9, wherein the calculation unit confirms that a separation distance between the peripheral wall portion of the movable tray and the candidate part with respect to the moving direction is equal to or more than the moving distance. Item supply apparatus of item 1.
(Supplement)
It is preferable that the component supply device includes an actuator that changes an inclination angle of the movable tray, and the control unit controls an operation amount of the actuator based on the movement distance and the movement direction. Alternatively, it is preferable that the control unit controls the tilt angle based on the movement distance and the movement direction.

[7. Modified example]
In the above-described embodiment, the robot hand 16 picked up with the component 40 sandwiched between the claws 17 is illustrated, but the pickup operation by the robot hand 16 is not limited to this. For example, an apparatus configuration that sucks up the component 40 using the robot hand 16 having a vacuum suction cup instead of the claw 17 may be used. In this case, by setting the second region 32 and the proximity region 33 according to the size of the suction cup, the same control as in the above-described embodiment can be performed, and the same operation and effect can be achieved.

  Moreover, in the above-mentioned embodiment, although the mounting surface 12 of the movable tray 11 is inclined from the horizontal state, the mounting surface 12 does not have to be strictly horizontal. By increasing at least the inclination of the mounting surface 12, each member 40 can be moved in the inclination direction, and the same effect as in the above-described embodiment can be obtained.

DESCRIPTION OF SYMBOLS 1 Parts pick-up program 2 Setting part 3 Pick-up part 4 Extraction part 5 Calculation part 6 Control part 10 Parts supply system 11 Movable tray 12 Mounting surface 13 Actuator 14 Perimeter wall part 15 Camera 16 Robot hand 17 Claw 20 Control apparatus (part supply apparatus)
21 processor 22 memory 23 auxiliary storage device 24 interface device 25 recording medium drive 26 internal bus 27 recording medium 31 first area 32 second area 33 proximity area 34 overlapping part 40 part 41 isolated part 42 candidate part

Claims (6)

In a component pick-up method in which a robot hand picks up one of the parts using an image obtained by photographing a plurality of parts placed on a movable tray.
For each of the components in the image, set a proximity region including a first region corresponding to the outer shape of the component and a second region corresponding to the gripping allowance of the robot hand,
When there is an isolated part in which the proximity area is separated from the first area of other parts, the robot hand picks up the isolated part,
When there is no isolated part, extract a candidate part where the proximity area overlaps the first area of a single other part,
Calculate the moving distance and moving direction of the candidate part that eliminates the overlap between the candidate part and other parts,
A component pickup method, comprising: controlling an operation of the movable tray based on the movement distance and the movement direction. When calculating the movement distance and the movement direction, the overlapping shape of the candidate part and other parts is approximated by a polygon, the width in the normal direction with respect to each side of the polygon is calculated, The component pickup method according to claim 1, wherein a minimum value of a width is the moving distance, and the normal direction that gives the minimum value is the moving direction. When controlling the operation of the movable tray, the operation of tilting the movable tray in the moving direction at an acceleration larger than the gravitational acceleration and then returning the movable tray to the original is repeated a number of times according to the moving distance. The component pick-up method according to claim 1 or 2. The operation of the movable tray is controlled based on the movement distance and the movement direction of the candidate part that minimizes the movement distance when there are a plurality of the candidate parts. 4. The part pickup method according to any one of items 3 to 3. When calculating the moving distance and the moving direction, it is confirmed that a separation distance between the peripheral wall portion of the movable tray and the candidate part with respect to the moving direction is equal to or more than the moving distance. The component pick-up method according to any one of claims 1 to 4. In a component supply apparatus for picking up one of the components by a robot hand using an image obtained by photographing a plurality of components placed on a movable tray,
For each of the components in the image, a setting unit that sets a proximity region including a first region corresponding to the outer shape of the component and a second region corresponding to the gripping allowance of the robot hand;
When there is an isolated part in which the proximity area is separated from the first area of other parts, a pickup unit that causes the robot hand to pick up the isolated part;
When there is no isolated part, an extraction unit that extracts a candidate part in which the proximity area overlaps the first area of a single other part;
A calculation unit for calculating a movement distance and a movement direction of the candidate part in which an overlap between the candidate part and another part is eliminated;
A control unit for controlling the operation of the movable tray based on the moving distance and the moving direction;
A component supply device comprising:

Images