JP2009136925A - Force display method and force display device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a force display method in which a suitable instruction is issued to a robot, so that a component part as a handling object of the robot is protected from being broken during execution of actual work by the robot after issuing the instruction, and to provide a force display device. <P>SOLUTION: The force display method for an instruction device is implemented by operating the handling object in a specific direction by a manipulated variable, and feed-backing a reaction which the handling object receives to the operator. The method comprises: a first step of measuring a reaction generated at each axis specifying a moving direction of the handling object; a second step of calculating a ratio of the measured reaction generated at each axis to a preset maximum allowance force; a third step of converting the calculated ratio into a symbol indicative of a magnitude relation corresponding to the same; and a fourth step of displaying the converted symbol. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a force display method and a force display device that can be suitably implemented, for example, when teaching a robot or the like.

A robot that performs operations such as welding, painting, parts assembly, disassembly, and conveyance at a production site teaches in advance the operation position and order of work objects by an apparatus having a position control function. The apparatus that teaches this position measures the absolute position and displacement of the work target component, and teaches the user to operate the work target component by operating the hand based on the absolute position and displacement. With this teaching, when moving the hand, the displacement of the hand is corrected so as to reproduce the same direction, posture, and force that the work target part receives from the hand as in the assembly and transport operations of the work target part. However, the manipulator device is controlled. (For example, refer to Patent Document 1).
JP 2004-160614 A (page 6-7, FIGS. 7 and 8)

  However, the process of using a robot is diverse, and the number of operations for handling small and precise parts is increasing. When performing position teaching in the vertical direction (Z-axis direction in the XYZ coordinate system) when picking a component with a hand so that the robot transports such a component, conventionally, the hand is operated to change the displacement of the hand. It was close to the part while correcting. However, in this case, delicate adjustment of the relative position between the component and the hand is necessary. In particular, when performing picking operation of a part with the nozzle for picking up the part at the position where the hand is in contact with the part, the hand or nozzle touches the part and damages it too much. There was a case where a delay occurred.

  It is an object of the present invention to provide a force display method and a force display device that do not damage a part to be handled during the operation of the robot after teaching by appropriately teaching the robot.

In order to solve the above-described problem, a force display method according to claim 1 of the present invention includes:
A force display method in a teaching device that operates an operation target by an operation amount in a specific direction and feeds back a reaction force received by the operation target to the operator.
A first step of measuring, for each axis, a reaction force generated on each axis that defines the moving direction of the operated object;
A second step of calculating, for each axis, a ratio value of the reaction force generated and measured on each axis with respect to a preset maximum allowable force;
A third step of converting the calculated ratio value into a symbol representing a corresponding magnitude relationship;
And a fourth step of displaying the converted symbol.

A force display device according to claim 2 of the present invention is
A force display device in a teaching device that operates an operation target by an operation amount in a specific direction and feeds back a reaction force received by the operation target to the operator.
Force measuring means for measuring, for each axis, a reaction force generated in each axis that defines the moving direction of the operated object;
A calculation means for calculating a ratio value of the reaction force generated and measured in each axis to a preset maximum allowable force for each axis;
Symbol conversion means for converting the ratio value calculated by the calculation means into a symbol representing a magnitude relationship corresponding thereto;
Display means for displaying the converted symbol.

  Since the force display method according to claim 1 and the force display device according to claim 2 have such a configuration, the strength of the component handled by the operated object can be fed back to the operation target. It is possible to visually grasp how much is within the allowable range, and it is possible to teach while enhancing the intuitive visibility of the degree of contact force with respect to the part to be operated. . As a result, when the operation target actually performs the work in accordance with the teaching content after teaching, it is possible to prevent an excessive force from being applied to the parts to be handled by the operation target and the operation target itself, thereby preventing the damage. .

  According to the force display device according to the present invention, a force display method and a force display device are provided that do not damage parts to be handled during actual robot work after teaching by performing appropriate teaching to the robot. it can.

  Hereinafter, a force display device according to an embodiment of the present invention will be described together with the force display method based on the drawings. As shown in FIG. 1, an overall configuration including a force teaching device having a force display device 1 according to an embodiment of the present invention includes a robot 10 as an actuator that performs a predetermined operation based on a taught operation, and a robot 10, a robot control unit 20 that drives 10, and a teaching box 30 that teaches and drives work of the robot 10 via the robot control unit 20.

  The robot 10 includes a robot arm 11 partially shown in FIG. 1, a handling hand 12 and a component suction nozzle 13 provided at the tip of the robot arm 11, a motor 14 for driving the robot 10, and a motor 14. A driver 15 for driving and a rotary encoder 16 for measuring an actual displacement amount of the robot arm 11 are provided, and a force sensor 17 is provided between the robot arm 11 and the hand 12 and the nozzle 13.

  The robot 10 moves in the X-axis direction (for example, the left-right direction of the paper surface in FIG. 1), the Y-axis direction (for example, the direction orthogonal to the paper surface in FIG. 1), and the Z-axis direction (for example, the vertical direction of the paper surface in FIG. 1). Any arm may be used as long as it is a robot in such a form. Therefore, the robot may be either a Cartesian coordinate system robot or a polar coordinate system robot.

  A robot arm 11 shown in FIG. 1 partially shows an arm tip portion provided with a hand 12 of the robot 10, and the hand 12 includes a nozzle 13 for sucking parts and is supplied to a production line 51, for example. The chip component 52 such as an IC chip is adsorbed while maintaining an accurate orientation in the XY axis direction, and is used to mount the chip component 52 at a predetermined position on a printed circuit board (not shown) while maintaining a desired XY axis direction. .

  The force sensor 17 individually measures a positive reaction force or a negative reaction force applied from the component 52 to the hand 12 or the nozzle 13 at the time of teaching with respect to each of the XYZ axis directions, and supplies the force to the AD converter 22 of the robot control unit 20. The measured value is transmitted as an analog signal.

  The motor 14 is composed of, for example, a servo motor, and a plurality of robot arms 11 are provided to move the hand 12 and the nozzle 13 to arbitrary positions in the XYZ axis directions, and are driven by a driver 15.

  The rotary encoder 16 detects the driving amount of each motor 14 and transmits the driving amount to the control calculation unit 21 of the robot control unit 20 through the driver 15 as a digital value.

  The robot control unit 20 includes a control calculation unit 21, an AD converter 22, a digital input unit 23, a pulse input unit 24, a pulse output unit 25, and a digital output unit 26, and also includes an RS-232C and the like. The teaching box 30 is electrically connected via a corresponding input / output port 27.

  The control calculation unit 21 of the robot control unit 20 incorporates a memory (not shown) here, controls basic operations of the robot 10 based on a program recorded in the memory, and is taught via the teaching box 30. It controls the execution of robot movement.

  The AD converter 22 of the robot control unit 20 changes the analog measurement value obtained from the force sensor 17 described above to a digital value and transmits it to the control calculation unit 21. The digital output unit 26 of the robot control unit 20 transmits the robot operation amount determined by the control calculation unit 21 to each motor 14 through the driver 15 as a digital value. The digital input unit 23 of the robot control unit 20 inputs the measurement value obtained from the rotary encoder 16 via the driver 15 to the control calculation unit 21 as a digital value. The pulse output unit 25 of the robot control unit 20 transmits the reference clock pulse to the driver 15 to synchronize the control calculation unit 21 and the motor 14, and the pulse input unit 24 controls the pulses from the rotary encoder 16. The information is transmitted to the calculation unit 21 so that the control calculation unit 21 and the rotary encoder 16 are synchronized.

  The teaching box 30 is for performing a teaching operation called so-called teaching on the robot 10. The teaching box 30 moves the hand 12 and the nozzle 13 of the robot 10 to arbitrary positions in the XYZ axes during teaching, and the hand 12 during teaching. And a display unit 32 for displaying information on reaction force received by the hand 12 or the part 52 that the nozzle 13 receives from the handling object 52 when the nozzle 13 is moved in an XYZ axial direction so that the operator can visually recognize the reaction force. ing.

  Next, the role of the display unit 32 of the teaching box 30 described above, which is a characteristic part of the present invention, will be described in detail together with the teaching operation of the robot 10.

  In the present embodiment, force information generated on each axis (X, Y, Z axis) of the hand 12 and nozzle 13 at the tip of the robot arm (reaction force information from the component 52 to be handled) is displayed on the display unit 32 of the teaching box 30. ) Is displayed. The display format is a ratio value (%) to the maximum allowable force of force information, converted into a corresponding magnitude relationship symbol, and the size is expressed. Intuitive visibility for the operator Is increasing.

  More specifically, when the force display device 1 feeds back the reaction force received by the hand 12 and the nozzle 13 when the robot moves in the X, Y, and Z axis directions, the hand 12 and the nozzle 13 of the robot 10 are fed back. The force generated on each of the X, Y, and Z axes that define the moving direction of each is measured by the force sensor 17, and the ratio of the reaction force generated and measured on each axis to the preset maximum allowable force Is calculated for each axis by the control calculation unit 21, and the calculated ratio value is converted into a symbol representing the magnitude relationship corresponding to this in the control calculation unit 21 or the teaching box 30. It is displayed on the display unit 32.

  This symbol indicates that the reaction force received by the hand 12 or the nozzle 13 is a positive reaction force (for example, a reaction force acting in a direction in which the hand 12 or the nozzle 13 receives a compressive force) or a one-way reaction force ( For example, the reaction force acting in the direction in which the hand 12 or the nozzle 13 receives the tensile force) can be instantaneously discriminated.

  FIG. 2 is a flowchart showing a force display method by the force display device 1. In FIG. 2, at the beginning of the teaching work, for example, the reaction force received from the component 52 when the hand 12 or nozzle 13 at the tip of the robot arm picks the component 52 is obtained as a feedback value from the force sensor 17, and this is converted into an AD converter. 22 is converted into a digital value, and measured by the control calculation unit 21 as reaction force information for each of the X, Y, and Z axes (step ST1).

  Subsequently, a preset maximum allowable force ratio value of the reaction force measurement value is calculated (step ST2). The preset maximum allowable force is, for example, the maximum value of the allowable force that is pressed against the hand 12 or the nozzle 13 of the robot 10 when the component 52 is picked, and can sufficiently withstand the strength. Pre-input to the memory. However, this maximum permissible force can be changed according to the subsequent change in the work environment of the robot 10.

  Next, based on the result of the ratio value calculated in step ST2, according to the conversion table shown in FIG. 4, the control operation unit 21 converts the ratio value into a symbol corresponding to the magnitude relationship of the ratio value (step ST3). The specific contents of this symbol will be described later in detail.

  Next, the converted symbol is displayed on the display unit 32 of the teaching box 30 (step ST4).

  Based on the symbol displayed on the display unit 32, the instructor determines how much reaction force the hand 12 or nozzle 13 of the robot 10 receives from the component 52 to be handled during teaching, that is, based on the subsequent teaching contents. During the operation of the robot 10 according to the above, while the teaching work is performed, it is visually shown how much force these components 52 receive during handling such as picking from the hand 12 or the nozzle 13 together with the direction of the reaction force. Can be grasped instantaneously.

  Subsequently, the display contents of the display unit 32 of the teaching box 30 will be specifically described. In the present embodiment, the display unit 32 of the teaching box 30 has display contents as shown in FIG. 3, and the hand 12 and the nozzle 13 are handled during teaching for each of the X axis, the Y axis, and the Z axis. An inequality sign that can visually grasp the magnitude relationship corresponding to the ratio of the reaction force received from a part to a preset allowable maximum value for each of the X, Y, and Z axes, including the direction of the reaction force. Display with a symbol.

  The contents shown in FIG. 3 will be described in more detail. In the X-axis direction, the reaction force in the-direction acts about 20% to 30% of the allowable maximum value, and almost no reaction force is generated in the Y-axis direction. In the Z-axis direction, the positive direction reaction force is acting about 10% to 20% of the allowable maximum value.

  As described above, in this embodiment, the direction of the reaction force received from the parts when teaching the hand or nozzle by changing the direction of the inequality sign is displayed separately for the negative direction and the positive direction. Here, the case where the reaction force acts in the positive direction means, for example, the case where the compressive force generated in the force sensor acts when the hand or nozzle is pressed against the part, and the case where the reaction force acts in the negative direction. For example, a case where a tensile force generated when a part to be handled is accommodated in a special container and pulled out through the hand is applied.

  FIG. 4 is a table showing a list of symbols displayed on the display unit 32 of the teaching box 30. Among the inequality symbols in this table, the reaction force calculated by the control calculation unit 21 based on the feedback value from the force sensor and the symbol corresponding to the above ratio value are selected and displayed on the display unit 32. It is like that.

  Specifically, the direction in which the force is applied is, for example, the + direction in which the pressing force acts on the component 52, and the ratio value (% display value relative to the allowable maximum force of the feedback force in the Z direction) is + 10%. If it is small and + 0.05% or more, the] symbol is displayed on the display.

  As the ratio value increases, the number of inequality signs in the same direction increases and the square bracket symbol is displayed as appropriate (not shown in FIG. 4). If the percentage value is + 80% or more and less than + 90%, the symbol >>> is displayed on the display, which indicates that the reaction force in the + direction is being applied from the part to the hand or nozzle. (Teacher) can recognize it instantly.

  When the direction in which the force is applied is the + direction and the ratio value is 90% or more and less than + 100%, the symbol >>> is displayed on the display unit, and the reaction force in the + direction is applied from the part to the hand or The operator can intuitively recognize that the nozzle is approaching the maximum allowable value.

  On the other hand, when the direction in which the force is applied is, for example, a negative direction in which a tensile force acts on the component, and the ratio value is greater than -0.05% and equal to or less than -10%, the symbol [is displayed on the display. When the direction in which the force is applied is the negative direction and the ratio value is greater than -10% and equal to or less than -20%, the symbol <is displayed on the display. As the percentage display increases, the number of inequality signs in the same direction increases, and the square bracket symbols are displayed as appropriate (not shown in FIG. 4). If the percentage value is -90% or more and less than -80%, the symbol <<< is displayed on the display unit, indicating that the force applied to the hand or nozzle is approaching the allowable maximum value. Can be recognized instantly.

  If the force is applied in the negative direction and the percentage value is -100% or more and less than -90%, the symbol <<<< is displayed on the display and the force applied to the hand or nozzle is allowed. The teacher can recognize that the maximum value is almost reached.

  As described above, when teaching (teaching programming) of a robot used for manufacturing work in an industrial application, the robot is taught the operation position using the teaching box. When displaying the position in the vertical direction (Z-axis direction) when handling the workpiece (part) to be transported by the robot in this teaching operation with the hand or nozzle, the operator operates the teaching box to move the workpiece to the workpiece from above. And move the nozzle closer. In the case of such a teaching operation, it is necessary to finely adjust the positions of the work, the hand, and the nozzle. That is, when the work is lifted by performing suction with the nozzle at a position where the hand or nozzle is brought into contact with the work, particularly fine adjustment is required.

  Conventionally, in such cases during teaching, there are cases where the workpiece is over-pressed with a hand or nozzle and damaged, leading to high manufacturing costs, delays in delivery, and delays in new product production due to teaching operations. However, by implementing the force display method using the force display device according to the present invention, such a problem can be avoided.

  In the above-described embodiment, the component to be handled has been introduced as an IC chip. However, the present invention is not necessarily limited to this, and the present invention is also applicable when handling a part including a brittle material such as a hermetic seal part. Is suitable.

  Specifically, unlike the above-described part picking, teaching work is performed when the hermetic seal part is pulled out from the object, particularly when the pulling direction is a direction including at least two of the X, Y, and Z axes. However, by applying the present invention, teaching work can be performed without applying excessive force to such hermetic seal parts.

  In addition, when the hermetic seal part including a part of a brittle material or a part made entirely of a brittle material is inserted into an insertion hole of an attachment object of the part, the present invention can be applied in the same manner. The effect can be exerted.

  The symbols used in the present invention are not limited to the inequality sign indicating the magnitude relationship of the ratio value and the direction in which the reaction force acts in the above-described embodiment, but the magnitude relationship in the ratio value and the direction in which the reaction force acts (positive) Icons that can be used to determine the direction or negative direction are also included.

  Specifically, using a circular icon, a positive reaction force acts when a black circle, a negative reaction force acts when a white circle, and the ratio of each reaction force to the maximum allowable value The size of the circle may be increased or decreased according to the magnitude relationship of the values.

  Moreover, you may use the staircase-shaped icon from which a climb direction differs. That is, when a positive reaction force is applied, a step-up icon is displayed to the right, and when a negative reaction force is applied, a step-up icon is displayed to the left. The number of steps of the stairs may be changed according to the magnitude relationship of the ratio value with respect to the maximum value.

  The robot to which the present invention is applied is not limited to an X, Y, Z axis orthogonal coordinate system or an R-θ polar coordinate system robot, and may be an XY axis orthogonal coordinate system.

  In the above-described embodiment, the robot arm is provided with both the hand and the nozzle, but either one may be provided.

  Further, the direction of the force display described above is not limited to the X, Y, and Z axis directions, and the ratio value with respect to the maximum allowable value of the reaction force (torque) received when the hand rotates in the U direction representing the rotation direction of the hand is described above. It may be represented by a symbol.

It is a schematic block diagram which shows the force display apparatus which concerns on one Embodiment of this invention with the robot in which this is used. It is a flowchart explaining the force display method using the force display apparatus shown in FIG. It is an example of the display content displayed on the display part of the teaching box shown in FIG. FIG. 2 is a list in which some symbols displayed on a display unit of a teaching box of the force display device illustrated in FIG. 1 are partially omitted.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Force display apparatus 10 Robot 11 Robot arm 12 Hand 13 Nozzle 14 Motor 15 Driver 16 Rotary encoder 17 Force sensor 20 Robot control part 21 Control operation part 22 AD converter 23 Digital input part 24 Pulse input part 25 Pulse output part 26 Digital output Part 27 I / O port 30 Teaching box 31 Movement button 32 Display part 51 Production line 52 Parts

Claims (2)

A force display method in a teaching device that operates an operation target by an operation amount in a specific direction and feeds back a reaction force received by the operation target to the operator.
A first step of measuring, for each axis, a reaction force generated on each axis that defines the moving direction of the operated object;
A second step of calculating, for each axis, a ratio value of the reaction force generated and measured on each axis with respect to a preset maximum allowable force;
A third step of converting the calculated ratio value into a symbol representing a corresponding magnitude relationship;
And a fourth step of displaying the converted symbols. A force display method in a teaching device. A force display device in a teaching device that operates an operation target by an operation amount in a specific direction and feeds back a reaction force received by the operation target to the operator.
Force measuring means for measuring, for each axis, a reaction force generated in each axis that defines the moving direction of the operated object;
A calculation means for calculating a ratio value of the reaction force generated and measured in each axis to a preset maximum allowable force for each axis;
Symbol conversion means for converting the ratio value calculated by the calculation means into a symbol representing a magnitude relationship corresponding thereto;
A force display device in a teaching device, comprising: display means for displaying the converted symbol.

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