JPWO2017033247A1 - Processing system and robot control method - Google Patents

Abstract

A processing system including a robot (3) that performs processing on a processing target with one or a plurality of arms, a position measurement sensor (2) provided in the arm, and a robot control device (1) that controls at least the robot. The robot control device includes a position measurement unit (23) that causes the position measurement sensor to measure a position of a device used when the robot performs processing on the processing target, and the measured device. A processing unit (22) that moves the arm with respect to the position of the target and performs processing on the processing target, and the processing unit includes the posture of the arm in the processing on the processing target, and the position measurement unit. A processing system that controls the arm so that a difference from the posture of the arm in the measurement of the position of the device is reduced.

Description

  The present invention relates to a processing system and a robot control method.

  Conventionally, there has been a case where the position of an object is measured in order to reliably hold the object by a robot arm. For example, Patent Document 1 described below describes a measurement system that measures the height position, planar position, and posture of a load with a laser marker and a CCD camera provided on a robot hand and causes the hand to perform a picking operation.

  Patent Document 2 below describes a scanning operation in which one or a plurality of edge positions of each side of a workpiece are measured by a position detection sensor mounted on a robot. Furthermore, Patent Document 3 below describes that three points (P1, P2, P3) on two orthogonal sides of the work object are measured by a contact position detection probe provided in the robot.

JP 09-105608 A Japanese Patent No. 5366018 Japanese Patent No. 5549223

  The robot arm may have multiple joints and may be able to approach the device with a plurality of different postures. In such a case, it should be possible to approach the same point ideally regardless of the posture of the device, but in reality, the backlash of the gears constituting each joint and the deflection of the robot arm The approach point may be shifted depending on the posture of the robot arm. For this reason, even if the position of the device is measured in advance, the approach point of the robot arm when performing work using the device may deviate from a desired point.

  Such a deviation in approach points does not cause a problem depending on the contents of the work, but there is a possibility that the work may be hindered when a precise work is performed.

  An object of the present invention is to provide a processing system and a robot control method capable of performing precise work by a robot arm.

  A processing system according to an aspect of the present invention includes a robot that performs processing on a processing target with one or a plurality of arms, a position measurement sensor provided in the arm, and a robot control device that controls at least the robot. In the processing system, the robot control device uses a position measurement sensor to measure a position of a device used when the robot performs processing on the processing target, and a position measurement unit. A processing unit that moves the arm with respect to a position and performs processing on the processing target, and the processing unit includes a posture of the arm in processing on the processing target, and a position of the device by the position measuring unit. The arm is controlled so that a difference from the posture of the arm in the position measurement becomes small.

  In the processing system according to another aspect of the present invention, the robot control device may include a calibration unit that calibrates the relationship between the position of the processing target in the device and the position of the arm.

  Further, in the processing system according to another aspect of the present invention, the robot control device is determined to cause the calibration unit to perform calibration, and the determination unit to determine whether or not to perform calibration. In some cases, it may include an insertion unit that inserts the calibration performed by the calibration unit before performing the process on the processing target.

  In the processing system according to another aspect of the present invention, the determination unit may determine whether or not to cause the calibration unit to perform calibration according to the type of processing for the processing target.

  In the processing system according to another aspect of the present invention, the determination unit may determine whether to cause the calibration unit to perform calibration according to at least one of the passage of time and the number of processes. .

  In the processing system according to another aspect of the present invention, the determination unit may determine whether or not to cause the calibration unit to perform calibration according to a standby time before performing the process on the processing target. .

  In the processing system according to another aspect of the present invention, the determination unit may determine that the calibration unit performs calibration when the robot stops due to an error.

  In the processing system according to another aspect of the present invention, the determination unit may determine that the calibration unit performs calibration when maintenance is performed on at least one of the robot and the device. .

  In the processing system according to another aspect of the present invention, the device has two sides in a direction intersecting with each other in a plan view, and the position measuring unit is configured to detect each of the two sides of the device by the position measuring sensor. The edge position may be measured at a plurality of locations.

  Further, in the processing system according to another aspect of the present invention, the robot control device configures coordinates representing the position of the processing target in the device based on the positions of the edges of the plurality of positions measured by the position measurement unit. You may have a coordinate composition part to do.

  In the processing system according to another aspect of the present invention, the position measurement unit may measure the position of the device located above the processing position where the processing on the processing target is performed by the position measurement sensor. It may be done.

  Further, in the processing system according to another aspect of the present invention, the apparatus further includes a fixture provided with an extending portion that fixes the device and extends upward, and the position measuring unit includes the extension of the fixture. You may make it measure the position by the said position measurement sensor about the upper surface of a part.

  According to another aspect of the present invention, there is provided a method for controlling a robot, wherein a position measurement sensor provided in one or more arms of the robot determines a position of a device used when the robot performs processing on a processing target. Measuring and moving the arm with reference to the measured position of the device, and adjusting the arm so that a difference between the posture of the moved arm and the posture of the arm in measuring the position of the device is reduced. And control the processing target by the robot.

It is the schematic which shows the physical structure of the processing system which concerns on embodiment of this invention. 1 is a configuration block diagram showing a physical configuration of a robot control apparatus according to an embodiment of the present invention. It is a functional block diagram of a robot control device, a position measurement sensor, and a robot according to an embodiment of the present invention. It is a perspective view which shows the external appearance of the tube rack which concerns on embodiment of this invention. It is a top view which shows two sides of the tube rack measured by the position measurement sensor which concerns on embodiment of this invention. It is a figure which shows the apparatus coordinate system comprised from the point measured by the position measurement sensor which concerns on embodiment of this invention. It is a perspective view which shows the fixing tool which concerns on embodiment of this invention. It is a flowchart about judgment of the necessity of calibration by the judgment part concerning the embodiment of the present invention. It is a flowchart about the control method of the robot which concerns on embodiment of this invention.

  FIG. 1 is a schematic diagram illustrating a physical configuration of a processing system 200 according to an embodiment of the present invention. The processing system 200 includes at least a robot controller 1 that controls the robot 3. The robot control device 1 itself may be a dedicated device, but here is realized using a general computer. That is, in a commercially available computer, the computer is used as the robot control device 1 by executing a computer program that causes the computer to operate as the robot control device 1. Such a computer program is generally provided in the form of application software, and is used by being installed in a computer. The application software may be provided by being recorded on an appropriate computer-readable information recording medium such as a CD-ROM, DVD-ROM, or may be provided through various information communication networks such as the Internet. Alternatively, it may be realized by so-called cloud computing in which the function is provided by a server at a remote place through an information communication network.

  The processing system 200 includes a position measurement sensor 2 provided on the first arm 3 a of the robot 3. The position measurement sensor 2 is a sensor for specifying the position of the measurement target with respect to the arm of the robot 3. The position measurement sensor 2 can detect a planar or three-dimensional position of a measurement object alone or with the movement of an arm. In the present embodiment, the position measurement sensor 2 is a laser sensor that irradiates a measurement target with laser light and measures the distance to the measurement target. The position measurement sensor 2 may not be a laser sensor, and for example, position detection using a camera capable of shooting a moving image or a still image, an ultrasonic sensor, a contact sensor, a magnetic sensor, or the like may be employed. In the present embodiment, by adopting a laser sensor as the position measurement sensor 2, it is possible to measure the distance to the measurement object in a non-contact and high accuracy.

  The processing system 200 includes a robot 3 that performs processing on a processing target with one or a plurality of arms. The robot 3 according to the present embodiment is an articulated robot, and performs processing on a processing target by the first arm 3a and the second arm 3b. The first arm 3a and the second arm 3b are arms that can perform processing on a processing target in a plurality of different postures. Specifically, it is an arm having joints of 7 axes or more. In the present embodiment, the processing target is a target to be subjected to a series of tests, culture, and amplification in the fields of biochemistry, biology, and biotechnology, and refers to, for example, cultured cells and drugs. However, the processing target may be other than that, and may be a part to be processed / assembled / disassembled such as welding or bolt tightening by the robot 3 or a package to be transported such as transport or palletizing. .

  The robot 3 according to this embodiment can operate a laboratory instrument (not shown or illustrated) such as holding and operating the pipette 4 accommodated in the pipette rack with a hand provided at the tip of the first arm 3a. The robot 3 holds the microtube 6 stored in the tube rack 5 with a hand provided at the tip of the second arm 3b, and moves the microtube 6 from the tube rack 5 to the vortex mixer 9, the centrifuge 10, or the like. Various containers (not shown or illustrated) can be moved, such as being moved. In the present embodiment, the robot 3 holds the pipette 4 with the hand provided at the tip of the first arm 3a and attaches the tip prepared in the tip rack 7 to the tip of the pipette 4 when sucking or injecting the chemical solution. And work. Here, the chip rack 7 is fixed to the work table by a fixture 8.

  In the example shown in FIG. 1, a vortex mixer 9 and a centrifuge 10 are included. However, these are examples of instruments used for experiments, and other instruments may be used in addition to or instead of these instruments. May be included. For example, the processing system 200 may include a rack for storing Petri dishes, a magnet rack, and the like. The robot 3 according to the present embodiment is a double-arm robot, and the robot 3 includes a first arm 3a and a second arm 3b. One or more arms included in the processing system 200 are, for example, a plurality of arms. May be separately provided and controlled so as to operate cooperatively by the robot control device 1.

The processing system 200 according to the present embodiment uses a plurality of coordinate systems in order to define a point P on the space that the tip of the arm of the robot 3 approaches. One is a robot coordinate system S _R associated with the robot 3. Robot coordinate system S _R is a coordinate system based on the robot 3, the origin in this example is a left-handed orthogonal coordinate system in the center of the robot 3. An arbitrary point is represented as coordinates (X, Y, Z) with reference to the robot 3. By using at least a robot coordinate system S _R, it can represent the tip of the coordinates of the robot arm 3. Coordinates of point P, represented by the robot coordinate system _{S R (X, Y, Z} ) is the angle of the joint of a plurality of (N) constituting the arm _{(θ 1, θ 2, ...} , θ N) corresponding to . In this specification, the angles (θ ₁ , θ ₂ ,..., Θ _N ) of a plurality of joints constituting the arm are referred to as arm postures. Here, when the degree of freedom (number of joints) of the arm is 7 degrees or more, when the tip of the arm is approached from a desired direction with respect to the point P, the angles of the joints of the arm (θ ₁ , θ ₂₎ ,..., Θ _N ) are not uniquely determined and have redundancy. Note that the origin of the robot coordinate system S _R is may be set to a point other than the center of the robot, the type of coordinate system used may be other than the Cartesian coordinate system.

In the processing system 200 according to the present embodiment, an equipment coordinate system _SD associated with equipment used when the robot 3 performs processing on the processing target, such as the tube rack 5, is also used. For example, the equipment coordinate system S _D1 associated with the tube rack 5 is a left-handed orthogonal coordinate system whose origin is at the upper corner of the tube rack 5, and coordinates (x ₁ , y representing the point P with respect to the tube rack 5 as a reference. ₁ , z ₁ ). By using the equipment coordinate system _SD1 , the accommodation location of the microtube 6 included in the tube rack 5 can be simply expressed. Further, by using the device coordinate system _SD , a coordinate system (spherical coordinates, cylindrical coordinates, etc.) suitable for the device can be set for each device. Further, even when the mounting position of the device on the workbench is changed, the position of the tip of the arm in the process does not change if expressed in the device coordinate system _SD , so the arm postures (θ ₁ , θ ₂ ,. There is an advantage that θ _N ) can be easily rewritten. The device coordinate system _SD may be configured and stored in advance on a simulator executed in the robot control device 1 or a computer placed outside.

In the example shown in FIG. 1, as an example of the instrument coordinate system _SD , in addition to the instrument coordinate system S _D1 associated with the tube rack 5, the instrument coordinate system S _D2 associated with the tip rack 7 and the centrifuge 10 are associated. The device coordinate system _SD3 is shown. These will be described in detail later.

When the processing system 200 causes the robot 3 to conduct experiments in the fields of biochemistry, biology, and biotechnology, the contents of the experiment can vary, and the equipment used for each experiment can be changed or the arrangement of the equipment can be changed. There is a demand to do. However, for example, in the treatment using the pipette 4, the tip attached to the tip of the pipette 4 is placed over the wall surface of the microtube 6 to inject the chemical solution, or the trace amount of the chemical solution contained in the microtube 6 is removed. In some cases, precise work such as suction is required, and high-precision arm control may be required. In such a case, even if the device coordinate system _SD is configured on the simulator, the point that the arm actually approaches may be shifted due to the influence of the backlash of the gears constituting each joint of the arm, the deflection of the arm, or the like. . Therefore, in order to perform a precise work, it is desirable to configure the device coordinate system _SD in a form in which an influence such as arm deflection is folded.

In the case of an arm having 7 degrees of freedom or more, even if the approach point and the approach direction are specified, the arm posture is redundant, but the robot control apparatus 1 according to the present embodiment is subject to processing. The arm is controlled so that the difference between the posture of the arm in the process for the above and the posture of the arm in the measurement of the position of the device by the position measurement sensor 2 becomes small. Here, a small difference in arm posture means that a difference vector (θ _processing) between an N-dimensional vector θ _process representing the arm posture during _processing and an N-dimensional vector θ _measurement representing the arm posture during _measurement. This means that the norm of −θ _measurement ) | θ _treatment −θ _measurement | is small. The vector difference norm | θ _treatment− θ _measurement | may be any value that can evaluate the difference in arm posture. For example, | (a ₁ , a ₂ ,..., A _N ) | = | A ₁ | + | a ₂ | +... || a _N | may be calculated as the sum of absolute values of the respective elements. In addition, since the magnitude of the influence of each joint on the posture of the arm differs for each joint, the norm of the vector difference may be evaluated by weighting each vector element representing the angle of each joint. A small vector difference norm | θ _treatment −θ _measurement | means that the norm value falls within the lower 25% of the possible values of the norm. In other words, when the norm of vector difference | θ _processing −θ _measurement | is equally divided into four numerical intervals from the minimum value to the maximum value, the norm value falls within the interval including the minimum value. In order to evaluate the magnitude of the difference in arm posture, the norm of the arm posture difference vector may be used instead of using the other evaluation function.

According to the robot control apparatus 1 according to the present embodiment, the arm posture at the origin of the device coordinate system _SD and the processing time are controlled by controlling the difference in arm posture between the processing time and the measurement time to be small. The difference between the position of the arm and the position of the arm becomes smaller, and the origin of the arm is adjusted in a manner in which the influence of backlash and deflection of each joint is folded. Therefore, according to the processing system 200 according to the present embodiment, the approach point of the arm is prevented from deviating from a desired point, the arm can be accurately aligned, and a precise work can be performed by the arm. it can. Even when the position of the device changes, the position of the device is accurately measured, and the arm can be accurately aligned with the device.

The robot control apparatus 1 according to this embodiment calibrates the relationship between the device coordinate system S _D and the robot coordinate system S _R. Here, the relationship between the device coordinate system S _D and the robot coordinate system S _R, the position of the processing target in the apparatus, a relationship between the position of the arm, specifically, by the instrument coordinate system S _D represented point P of coordinates (x, y, z), refers to the transformation matrix a for converting the robot coordinate system _S P output coordinate points represented by _R (X, Y, Z) on. The transformation matrix A is generally a 3 × 3 matrix and is a 6-degree-of-freedom matrix representing translation and rotation. Processing system 200 according to this embodiment, by precisely constitutes the instrument coordinate system S _D, the relationship between the device coordinate system S _D and the robot coordinate system S _R, i.e. calibrating the transformation matrix A, by the arm It enables precise work.

  FIG. 2 is a block diagram showing a physical configuration of the robot control apparatus 1 according to the embodiment of the present invention. The configuration shown in FIG. 2 shows a general computer used as the robot control device 1, and includes a CPU (Central Processing Unit) 1a, a RAM (Random Access Memory) 1b, an external storage device 1c, and a GC (Graphics Controller). 1d, an input device 1e and an I / O (Inpur / Output) 1f are connected by a data bus 1g so that electrical signals can be exchanged with each other. Here, the external storage device 1c is a device capable of recording information statically, such as an HDD (Hard Disk Drive) or an SSD (Solid State Drive). The signal from the GC 1d is output to a monitor 1h such as a flat panel display where the user visually recognizes the image and displayed as an image. The input device 1e is a device for a user to input information such as a keyboard, a mouse, and a touch panel, and the I / O 1f is an interface for the robot controller 1 to exchange information with an external device.

  FIG. 3 is a functional block diagram of the robot control device 1, the position measurement sensor 2, and the robot 3 according to the embodiment of the present invention. Note that the functional blocks shown here are shown paying attention to the functions of the robot control device 1 and the like, and there is not necessarily a one-to-one physical configuration corresponding to each functional block. Some functional blocks are realized by an information processing device such as the CPU 1a of the robot control device 1 executing specific software, and some functional blocks are stored in a specific storage area in an information storage device such as the RAM 1b of the robot control device 1. May be realized by being assigned.

  The robot control apparatus 1 has an input unit 20 that receives various inputs from a user. In addition, the robot control apparatus 1 includes an operation command generation unit 21 that generates an operation command that is a command for controlling the operation of the robot 3 based on an input received by the input unit 20. Furthermore, the robot control apparatus 1 includes an operation command storage unit 27 that stores electronic data of the generated and generated operation commands, and an operation command output that outputs the generated operation commands as an electronic file that can be read by the robot. Unit 28 and an operation command display unit 29 that forms electronic data of the operation command stored in the operation command storage unit 27 and displays it on the monitor 1h.

  The input unit 20 is normally configured by the input device 1e shown in FIG. 2, but when the robot control apparatus 1 is an application server used for cloud computing, the user's terminal on a remote terminal is used. This corresponds to the I / O 1f to which the operation information is input.

  The operation command generation unit 21 includes various functional blocks for generating an operation command. Although details will be described later when the operation command generation procedure is described, the operation command generation unit 21 according to the present embodiment is used by the position measurement sensor 2 when the robot 3 performs processing on the processing target. A position measurement unit 23 that measures the position of the device to be measured, a processing unit 22 that moves the arm based on the measured position of the device and performs processing on the processing target, a position of the processing target in the device, and a position of the arm And a calibration unit 24 that calibrates the relationship between In addition, the operation command generation unit 21 determines whether or not the calibration unit 24 performs calibration. When the determination unit 26 determines that calibration is to be performed, the calibration by the calibration unit 24 is performed. Are inserted before the processing on the processing target is performed.

  In this specification, an operation command is a single job or a collection of jobs in which a plurality of jobs are combined, and is recognized as a unit for a processing target or a container that stores the processing target. A command that instructs the processing to be performed.

  In the processing system 200 according to the present embodiment, the equipment used when the robot 3 performs processing on the processing target includes the pipette 4, the tube rack 5, the microtube 6, the tip rack 7, the fixture 8, and the vortex. It refers to the mixer 9 and the centrifuge 10. Needless to say, these are merely examples, and generally, other materials may be included. Any device included in the processing system 200 can be a device used when the robot 3 performs processing on a processing target.

  The position measurement unit 23 includes an edge measurement unit 23a, a coordinate configuration unit 23b, an upper measurement unit 23c, and a fixture measurement unit 23d.

  The edge measurement unit 23a causes the position measurement sensor 2 to measure the positions of the edges for each of the two sides of the device used when the robot 3 performs processing on the processing target. The coordinate configuration unit 23b configures coordinates representing the position of the processing target in the device based on the positions of the edges of the plurality of locations measured by the edge measurement unit 23a included in the position measurement unit 23. The upper measurement unit 23c causes the position measurement sensor 2 to measure the position of the device located above the processing position where the processing on the processing target is performed. The fixture measuring unit 23d fixes the device and causes the position measurement sensor 2 to measure the position of the upper surface of the extending portion of the fixture provided with the extending portion extending upward.

  The determination unit 26 includes a process type determination unit 26a, a time / count determination unit 26b, a standby determination unit 26c, an error determination unit 26d, and a maintenance determination unit 26e.

  The processing type determination unit 26a determines whether or not to cause the calibration unit 24 to perform calibration according to the type of processing for the processing target. The time / number of times determination unit 26b determines whether or not to cause the calibration unit 24 to perform calibration according to at least one of the passage of time and the number of processes. The standby determination unit 26c determines whether or not to cause the calibration unit 24 to perform calibration according to the standby time before performing the process on the processing target. The error determination unit 26d determines that the calibration unit 24 performs calibration when the robot 3 stops due to an error. The maintenance determination unit 26e determines that the calibration unit 24 performs calibration when maintenance is performed on at least one of the robot 3 and the device used when the robot 3 performs processing on the processing target.

  FIG. 4 is a perspective view showing an appearance of the tube rack 5 according to the embodiment of the present invention. FIG. 5 is a top view showing two sides of the tube rack 5 measured by the position measurement sensor 2 according to the embodiment of the present invention. The tube rack 5 includes a base 5a that is fixed to a work table with bolts, an upper plate 5b that has six holes for accommodating the microtubes 6, and a column 5c that connects the upper plate 5b to the base 5a. The The tube rack 5 has a first side E1 and a second side E2 in a direction intersecting with each other in plan view. FIG. 5 illustrates a scanning trajectory of the laser sensor that is the position measurement sensor 2 in the present embodiment, and the first scanning trajectory S1 that is the scanning trajectory for the first side E1 and the second side E2. The second scanning trajectory S2 that is the scanning trajectory of is shown. Laser light from the laser sensor is irradiated from above toward the upper plate 5b of the tube rack 5, and is scanned from the inner side to the outer side of the upper plate 5b. When the laser beam crosses the edge of the upper plate 5b, a jump occurs in the distance measured by the laser sensor. The edge measuring unit 23a obtains the arm posture (angle of each joint) when the laser beam jumps across the edge of the upper plate 5b and the distance to the upper plate 5b measured by the laser sensor. From the posture of the arm at the edge of the edge, the planar position of the edge of the edge expressed in robot coordinates can be calculated, and the three-dimensional position of the edge of the edge is obtained together with the distance measured by the laser sensor. Can do.

  The edge measurement unit 23a causes the position measurement sensor 2 to measure the positions of the edges at a plurality of locations for each of the first side E1 and the second side E2 of the tube rack 5. In the example shown in FIG. 5, the position of the edge is measured at six places on the first side E1, and the position of the edge is measured at four places on the second side E2. As the number of measurement points increases, the influence of the error can be reduced. However, since the time required for measurement becomes longer, the number of measurement points is set in consideration of the balance between the two. In order to configure the device coordinate system, three points on the device may be measured. For example, the corner points at both ends of the first side E1 of the tube rack 5 and the corner points of the second side E1. However, errors occur due to various factors in the measurement. According to the edge measurement unit 23a according to the present embodiment, the coordinates can be configured with higher accuracy than when the coordinates are configured by measuring three points of the device. As a result, the arm can be positioned more accurately.

  In addition, the support | pillar 5c of the tube rack 5 which concerns on this embodiment is provided in the position away from the edge of the upper board 5b so that it may not interfere with the scanning of a laser sensor. Thereby, it is possible to prevent the laser sensor from erroneously detecting the step due to the support column 5c, and the position of the tube rack 5 can be measured smoothly.

  In FIG. 4, the processing position 6a where the process with respect to the process target accommodated in the microtube 6 is performed is indicated by an asterisk. In the example of FIG. 4, the processing position is a position where the tip end of the pipette 4 is aligned. The upper measurement unit 23c according to the present embodiment causes the position measurement sensor 2 to measure the position of the device located above the processing position 6a. The upper plate 5b of the tube rack 5 is a part of the equipment (tube rack 5) located above the processing position 6a. By measuring the position of the part of the equipment positioned above the processing position 6a (for example, the upper plate 5b of the tube rack 5), the part of the equipment positioned below the processing position 6a (for example, the base of the tube rack 5) As compared with the case of measuring the position in 5a), the position of the arm at the time of measurement is closer to the position of the arm at the time of processing, and the position can be measured in a state where influences such as backlash and arm deflection are further reduced. it can. It is particularly advantageous to cause the position measurement sensor 2 to measure the position of the device located above the processing position 6a when the measurable range of the position measurement sensor 2 is limited. If the position of the base 5a is measured when the measurable range of the position measurement sensor 2 is limited, it is necessary to bring the position measurement sensor 2 close to the base 5a. This is because the posture may be bent downward from the posture of the arm.

FIG. 6 is a diagram showing a device coordinate system composed of points measured by the position measurement sensor 2 according to the embodiment of the present invention. In the figure, for the sake of simplicity, two-axis coordinates that define points on the upper plate 5b are shown, but there is another axis in a direction perpendicular to the paper surface, and the coordinate system is composed of a total of three axes. . The coordinate configuration unit 23b according to the present embodiment is based on a plurality of edge positions E10 of the first side E1 and a plurality of edge positions E20 of the second side E2 measured by the edge measurement unit 23a. Thus, coordinates (device coordinates S _D ) representing the position of the processing target in the tube rack 5 are configured. The coordinate configuration unit 23b calculates a straight line overlapping the first side E1 from the plurality of edge positions E10 with respect to the first side E1, and calculates the x-axis 50. Here, as a method of calculating a straight line from a plurality of points, the least square method can be adopted, but another algorithm may be adopted. In addition, the coordinate configuration unit 23b calculates a straight line overlapping the second side E2 from a plurality of edge positions E20 with respect to the second side E2, and calculates the y-axis 51. Then, the origin 52 of the device coordinates is calculated from the intersection 52 where the x-axis 50 and the y-axis 51 intersect and the height of the upper plate 5b measured by the position measurement sensor 2. Further, by applying the dimensions of the upper plate 5b measured in advance, the coordinates 53 of the end of the upper plate 5b in the x-axis 50 and the coordinates 54 of the end of the upper plate 5b in the y-axis 51 are determined. The device coordinate system _SD1 is determined.

  According to the coordinate configuration unit 23b according to the present embodiment, by calculating the coordinate axis based on a plurality of measurement points and configuring the coordinates, the influence of errors when measuring each measurement point is reduced, and the device coordinate system Can be configured with higher accuracy. As a result, the processing system 200 capable of precisely aligning the tool such as the pipette 4 is obtained.

  FIG. 7 is a perspective view showing the fixture 8 according to the embodiment of the present invention. The fixture 8 is an instrument for fixing the chip rack 7 to the work table. The fixture 8 and the chip rack 7 are relatively accurately aligned and fixed with screws or the like, and the fixture 8 and the work table are detachably fixed with bolts or the like. The device fixed by the fixture 8 may be other than the chip rack 7. The fixture 8 according to the present embodiment is provided with an extending portion 8a extending upward. The extending portion 8 a may be formed of the same material as the bolted portion of the fixture 8, and the upper surface is in a surface state suitable for measurement by the position measurement sensor 2. When the position measurement sensor 2 is a laser sensor, the upper surface of the extending portion 8a is a smooth surface.

The fixture measuring unit 23 d according to the present embodiment causes the position measurement sensor 2 to measure the position of the upper surface of the extending portion 8 a of the fixture 8. And the coordinate structure part 23b comprises apparatus coordinate system _SD2 based on the position of the edge of the upper surface of the extending | stretching part 8a measured. Further, the height of the upper surface of the extending portion 8 a is close to the height of the upper surface of the chip rack 7. Therefore, the difference between the posture of the arm when the position measurement sensor 2 performs measurement on the upper surface of the extending portion 8a and the posture of the arm when the tip rack 7 is attached to the pipette 4 is the base of the fixture 8 ( This is smaller than the difference between the posture of the arm when measuring the position of the lower plate portion to be bolted) and the posture of the arm when attaching the tip to the pipette 4 with respect to the tip rack 7. The fixture 8 having the extending portion 8a is particularly advantageous when the measurable range of the position measurement sensor 2 is limited. When the measurable range of the position measurement sensor 2 is limited, it is necessary to bring the position measurement sensor 2 close to the fixture 8 in order to measure the position of the fixture 8, and the posture of the arm at the time of measurement is the position of the arm at the time of processing. This is because the posture may be bent downward from the posture.

  According to the fixture measuring unit 23d according to the present embodiment, the posture of the arm when measuring the upper surface of the extending portion 8a by the position measurement sensor 2 is close to the posture of the arm when performing processing using the device, The position can be measured in a state where the influence of backlash and arm deflection is further reduced. Therefore, the arm is positioned more accurately in the process using the device, and the accuracy of the process using the device is improved.

In the example shown in FIG. 1, a reference flat plate 11 is provided on the upper surface of the centrifuge 10. The position measurement unit 23 according to the present embodiment causes the position measurement sensor 2 to measure the position of the reference flat plate 11. And the coordinate structure part 23b comprises apparatus coordinate system _SD3 based on the position of the edge of the measured reference | standard flat plate 11. FIG. The reference flat plate 11 is provided when the device does not have an edge suitable for measurement, such as a rounded chamfered side of the device or a complicated shape. By providing the reference flat plate 11 so that the relative position between the device and the reference flat plate 11 is determined at a predetermined position, even if the device itself does not have a portion suitable for measurement by the position measuring sensor 2, the reference flat plate 11 is provided. By measuring the position of the flat plate 11, the position of the device can be indirectly measured. Since the position where the processing target is accommodated in the device and the position of the reference plate 11 are approximate, the difference in the posture of the arm during measurement and processing can be reduced, and the measurement can be performed accurately. Matching can be performed precisely.

  FIG. 8 is a flowchart for determining the necessity of calibration by the determination unit 26 according to the embodiment of the present invention. The processing type determination unit 26a of the determination unit 26 determines whether or not to cause the calibration unit 24 to perform calibration according to the type of processing for the processing target. The process type determination unit 26a according to the present embodiment determines that the calibration unit 24 performs calibration when the process for the processing target is a process using the pipette 4 (ST100). This is because the process using the pipette 4 is a process that requires particularly high precision and requires precise control of the arm. The processing type determination unit 26a may determine that the calibration unit 24 performs calibration when processing other than processing using the pipette 4 is performed. For example, when a drug sensitive to a physical impact is handled, the calibration unit 24 may be calibrated prior to processing so that the arm can be precisely controlled.

  According to the process type determination unit 26a according to the present embodiment, it is possible to perform calibration in advance for a process that needs to control the arm with particularly high accuracy, and it is possible to perform a precise work by the arm. On the other hand, calibration can be omitted for a process that does not cause a problem even if the arm is controlled with relatively rough accuracy, and the working time can be shortened.

  The time / number of times determination unit 26b of the determination unit 26 determines whether or not to cause the calibration unit 24 to perform calibration according to at least one of the passage of time and the number of processes. The time / frequency determination unit 26b according to the present embodiment causes the calibration unit 24 to perform calibration when the robot 3 has not been operating for a long time (ST101). For example, when the robot 3 has not been operated for 24 hours or more, it may be determined that the calibration unit 24 performs calibration. As a result, when the robot 3 has not been operated for a long time, calibration is automatically performed, and a reduction in work accuracy can be prevented.

  Further, the time / number of times determination unit 26b according to the present embodiment causes the calibration unit 24 to perform calibration when the number of times that the processes performed on the processing target by the robot 3 are equal to or greater than a predetermined value (ST102). For example, when the robot 3 performs the process 1000 times or more without performing calibration by the calibration unit 24, it may be determined that the calibration unit 24 performs calibration. Thereby, when the robot 3 continues to operate for a long time (when the accumulated number of processes becomes equal to or greater than a predetermined value), the calibration is automatically performed, and a decrease in work accuracy can be prevented.

  The standby determination unit 26c of the determination unit 26 determines whether or not to cause the calibration unit 24 to perform calibration according to the standby time before performing the process on the processing target. The standby determination unit 26c according to the present embodiment determines that the calibration unit 24 performs calibration when the standby time before performing the process on the processing target is 5 minutes or longer (ST103). It goes without saying that the waiting time serving as the threshold may be arbitrarily set by the user. As a result, calibration can be performed during the waiting time of the robot 3, and the working accuracy can be improved by effectively using the waiting time.

  The error determination unit 26d of the determination unit 26 determines that the calibration unit 24 performs calibration when the robot 3 stops due to an error. The error determination unit 26d according to this embodiment determines that the calibration by the calibration unit 24 is performed when the robot 3 is urgently stopped due to a natural disaster or an accident, or when the robot 3 is urgently stopped by the user. (ST104). As a result, calibration is automatically performed when a shortage such as a natural disaster occurs, and even if the user does not always monitor the processing system 200, the accuracy of the work is reduced due to an unexpected situation. Is prevented.

  The maintenance determination unit 26e of the determination unit 26 determines that the calibration unit 24 performs calibration when the maintenance is performed on at least one of the robot 3 and the device. In the processing system 200 according to the present embodiment, the robot 3 and equipment are arranged in a booth isolated from the outside. The maintenance determination unit 26e according to the present embodiment determines that the maintenance has been performed on at least one of the robot 3 and the device when the booth where the robot 3 and the device are arranged is opened and closed, and performs calibration to the calibration unit 24. (ST105). The maintenance determination unit 26e may determine whether the calibration unit 24 performs calibration by detecting the presence or absence of maintenance using a sensor provided in the robot 3 or the device. Thus, calibration is automatically performed after maintenance that may change the state of the arm of the robot 3 or change the fixed position of the device, thereby preventing a reduction in work accuracy.

As described above, when it is determined by the determination unit 26 that the calibration unit 24 performs calibration, the insertion unit 25 inserts calibration by the calibration unit 24 before performing processing on the processing target (ST106). The calibration unit 24 calibrates the relationship between the position of the processing target in the device and the position of the arm. That is, the calibration unit 24 acquires an instrument coordinate system S _D structure based on a measurement by the position measurement unit 23, to calibrate the conversion matrix A between the device coordinate system S _D and the robot coordinate system S _R . As a result, the position of the processing target or device represented by the device coordinate system _SD can be accurately read as the posture of the arm of the robot 3 (angle of each joint), and precise work by the arm is possible. In addition, if there is a possibility that the position of the device that accommodates the processing object may be shifted without an explicit command from the user, calibration is automatically performed prior to the processing. It is possible to prevent misalignment in the alignment.

  The order of determination by the determination unit 26 described above is an example, and the priority of determination by the process type determination unit 26a, the time / number of times determination unit 26b, the standby determination unit 26c, the error determination unit 26d, and the maintenance determination unit 26e is: It may be set by the user.

  FIG. 9 is a flowchart of the robot control method according to the embodiment of the present invention. In the robot control method according to the present embodiment, first, the position of the device used when the robot 3 performs processing on the processing target is determined by the position measurement sensor 2 provided in one or more arms of the robot 3. Measure (ST200). Thereafter, the arm is moved based on the measured position of the device, the arm is controlled so that the difference between the posture of the arm to be moved and the posture of the arm in the measurement of the position of the device becomes small. Processing is performed on the processing target (ST201).

According to the control method of the robot according to the present embodiment, the arm posture at the origin of the device coordinate system _SD is controlled by controlling so that the difference in arm posture between processing and measurement is small. The difference between the position of the arm and the position of the arm becomes smaller, and the origin of the arm is adjusted in a manner in which the influence of backlash and deflection of each joint is folded. For this reason, the approach point of the arm is prevented from deviating from a desired point, the arm can be accurately aligned, and a precise operation can be performed by the arm. Even when the position of the device changes, the position of the device is accurately measured, and the arm can be accurately aligned with the device.

  The configuration of the embodiment described above is shown as a specific example, and the invention disclosed in this specification is not intended to be limited to the configuration of the specific example itself. Those skilled in the art may make various modifications to these disclosed embodiments, for example, changes or additions of functions and operation methods, and the control shown in the flowchart is replaced with other control having an equivalent function. May be. It should be understood that the technical scope of the invention disclosed herein includes such modifications.

Claims (13)

A robot that performs processing on a processing target with one or more arms;
A position measuring sensor provided on the arm;
A robot control device that controls at least the robot,
The robot controller is
A position measuring unit that measures the position of a device used when the robot performs processing on the processing target by the position measuring sensor;
A processing unit that moves the arm with reference to the measured position of the device and performs processing on the processing target,
The processing unit controls the arm so that a difference between the posture of the arm in the processing for the processing target and the posture of the arm in the measurement of the position of the device by the position measurement unit is small;
Processing system. The robot controller is
A calibration unit that calibrates the relationship between the position of the processing target in the device and the position of the arm;
The processing system according to claim 1. The robot controller is
A determination unit for determining whether to cause the calibration unit to perform calibration;
When it is determined by the determination unit that calibration is performed, an insertion unit that inserts the calibration by the calibration unit before performing processing for the processing target;
The processing system according to claim 2, further comprising: The determination unit determines whether to cause the calibration unit to perform calibration according to the type of processing for the processing target.
The processing system according to claim 3. The determination unit determines whether to cause the calibration unit to perform calibration according to at least one of the passage of time and the number of processes.
The processing system according to claim 3 or 4. The determination unit determines whether or not to cause the calibration unit to perform calibration according to a standby time before performing the process on the processing target.
The processing system of any one of Claims 3-5. The determination unit determines that the calibration unit performs calibration when the robot stops due to an error,
The processing system according to any one of claims 3 to 6. The determination unit determines that the calibration unit performs calibration when maintenance is performed on at least one of the robot and the device.
The processing system according to any one of claims 3 to 7. The device has two sides in a direction crossing each other in plan view,
The position measuring unit causes the position measuring sensor to measure the position of an edge at a plurality of locations for each of the two sides of the device.
The processing system of any one of Claims 1-8. The robot controller is
Based on the positions of the edges of a plurality of locations measured by the position measurement unit, further comprising a coordinate configuration unit that configures coordinates representing the position of the processing target in the device,
The processing system according to claim 9. The position measurement unit causes the position measurement sensor to measure the position of the part of the device located above the processing position where the processing on the processing target is performed;
The processing system of any one of Claims 1-10. The apparatus further includes a fixture provided with an extending portion that fixes the device and extends upward,
The position measuring unit causes the position measuring sensor to measure the position of the upper surface of the extending portion of the fixture;
The processing system of any one of Claims 1-11. The position measurement sensor provided in one or more arms of the robot measures the position of the device used when the robot performs processing on the processing target,
The arm is moved based on the measured position of the device, and the arm is controlled so that a difference between the posture of the moved arm and the posture of the arm in the measurement of the position of the device is reduced. , Processing the processing target by the robot;
Robot control method.

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