TWI423377B - Workpiece handling equipment - Google Patents

Description

Workpiece handling device

The present invention relates to a workpiece conveying device that transports a workpiece held by a workpiece holding device by a cantilever-supporting arm in a horizontal direction, and particularly relates to a position of a control point capable of deviating from the arm deflection. Workpiece handling device.

In a semiconductor manufacturing system for substrate processing such as a liquid crystal glass substrate or a semiconductor wafer, a processing unit is disposed in each processing step, and the substrate is sequentially transported to the processing unit to perform a uniform process on the substrate.

Fig. 7 is a view showing the configuration of a workpiece conveying device. Here, the robot 102 in which the plurality of axes are configured is inserted into the glass substrate 107 when the substrate housing 100 of the plurality of substrates after the continuity processing is temporarily stored. The robot 102 supplies motor drive power from the control device 104 via the cable 103 to perform an action. The control device 104 is connected to the teaching means 106 via a cable 105. The teaching means 106 has a plurality of buttons that can be output to the control device 104 via the cable 105 by pressing each button. The control device 104 outputs the motor drive power to the robot 102 via the cable 103 in accordance with the above instruction. The teaching means 106 is, for example, a general-purpose computer or a personal computer. The substrate housing cassette 100 is provided with a support plug 101 for holding or supporting the glass substrate 107.

Fig. 8 is a view showing the configuration of the robot 102. The first arm link 108 is supported by the winding portion 129 through the first arm shaft 114. An arm shaft motor 115 is provided inside the first arm link 108, and is coupled to the arm shaft reducer 116. The rotation of the arm shaft motor 115 causes the first arm shaft 114 coupled to the arm shaft reducer 116 to rotate. However, since the first arm shaft 114 is supported by the winding portion 129, the first arm link 108 is the first arm. The shaft 114 is centered for winding.

The first link belt 117 is provided inside the first arm link 108, and the power is transmitted from the arm shaft reducer 116 to the second arm shaft reducer 119 to which the second arm shaft 118 is coupled. The second arm shaft reducer 119 has a characteristic that it can rotate in the opposite direction to the arm shaft reducer 11. That is, the rotation of the arm shaft motor 115 drives the first link belt 117, the second arm shaft reducer 119 rotates, and the second arm shaft 118 coupled thereto rotates, so that the second arm link 109 is second. The arm shaft 118 is centered in the opposite direction to the first arm shaft 114. A second link belt is provided inside the second arm link 109, and power can be transmitted from the second arm shaft reducer 119 to the flange reducer 121. The flange reducer 121 has a characteristic that it can rotate in the opposite direction to the second arm shaft reducer 119. Further, the reduction ratio of each of the reduction gears (the arm shaft reducer 16, the second arm shaft reducer 119, and the flange reducer 121) is set such that the rotation angle of the first arm shaft 114 and the rotation angle of the flange 112 are equal. Further, the distance from the center of the first arm shaft 114 to the center of the second arm shaft 118 is set to be equal to the distance from the center of the second arm shaft 118 to the center of the flange 122.

Based on the above mechanism, the rotation of the arm shaft motor 115 causes the first arm shaft 114 coupled to the arm shaft reducer 116 to rotate, and also transmits power from the arm shaft reducer 116 through the first link belt 117 to make the second The arm shaft reducer 119 rotates. The rotation of the second arm shaft reducer 119 causes the second arm shaft 118 connected thereto to rotate in the opposite direction of the first arm shaft 114, and also transmits the second link belt 120 from the second arm shaft reducer 119. The power is transmitted to rotate the flange reducer 121. The rotation of the flange reducer 121 causes the flange 122 connected thereto to rotate in the opposite direction of the second arm shaft 118, that is, in the same direction as the first arm shaft 114. Further, since the rotation angle of the first arm shaft 114 and the rotation angle of the flange 122 are equal, the first arm shaft 114 is wound around the center to the center of the second arm shaft 118, and the second arm shaft 118 is wound around the center to the center of the flange 122. When the distance between the glass substrate 107 that is held or placed by the workpiece holding device 110 and the workpiece holding device 110 and the robot 102 that is controlled by the control device 104, the control point 123 that is the target of the operation control is formed in the X-axis direction. Straight line action.

The telescopic state of the arm (the first arm link and the second arm link) of the robot 102 is shown in FIGS. 9 and 10 . Fig. 9 and Fig. 10 are diagrams showing the state of the arm extension when the robot of Fig. 8 is viewed from the positive direction of the Z axis. In the figure, the figure a is a distance indicating the center of the first arm shaft 114 from the center of rotation to the center of the second arm shaft 118. Based on the figure number a being equal to the distance from the center of the second arm shaft 118 to the center of the flange 122, the triangle formed by the first arm shaft 114 about the center and the second arm shaft 118 is wound around the center such as the flange 122. Become the isosceles triangle shown in the figure. The bottom edges r1 and r2 of the isosceles triangle are the distance from the center of the first arm shaft 114 to the center of the flange 122 (the length of expansion and contraction of the arm). For example, when the first arm shaft 114 is rotated by the angle α1, the angle formed by the connecting line connecting the second arm shaft 118 from the first arm shaft 114 and the connecting line connecting the flanges 122 from the first arm shaft 114 becomes β1. However, the flange 122 is only rotated at the same angle as the first arm shaft 114 in the opposite direction of the second arm shaft 118 based on the above mechanism, so that the orientation of the workpiece holding device 110 is from the second arm shaft 118 to the flange 122. Extend the line in a counterclockwise direction at an angle β 1 (see Figure 9). Further, for example, when the first arm shaft 114 is wound at an angle of α 2 , the angle is β 2 (see FIG. 10 ).

Therefore, the orientation of the workpiece holding device 110 can be maintained constant during the arm stretching operation. The telescopic length r of the arm is calculated according to the formula (1).

r=2asin(α).........(1)

In the eighth drawing, the lift shaft motor 124 is coupled to a speed reducer (not shown), and the drive is transmitted to the unillustrated speed reducer connected to the lift attachment unit 125 by a belt (not shown) provided in the lower lift link 112. . Further, a speed reducer (not shown) to which the speed reducer and the elevation support unit 126, which are connected to the lift shaft motor 124, are connected, is driven by a belt (not shown) provided in the upper lift link 111. The speed reducer (not shown) connected to the speed reducer and the lift support unit 126, which are connected to the lift attachment unit 125, has a characteristic that the speed reducer can be rotated in the opposite direction to the speed reducer (not shown) connected to the lift shaft motor 124. Further, the distance between the center of the lift attachment portion 125 and the winding center of the unillustrated speed reducer coupled to the lift shaft motor 124 is set, and the center of the unwinding speed of the lower shaft of the lift shaft motor 124 to the lift support portion 126 is set. The distance is equal.

In the above configuration, the rotation of the lift shaft motor 124 rotates a speed reducer (not shown) connected to the lift shaft motor 124, and drives a belt (not shown) provided inside the lower lift link 112 and the upper lift link 111. The speed reducer (not shown) connected to the lift shaft motor 124 rotates in a direction opposite to a speed reducer (not shown) connected to the lift shaft motor 124, and a speed reducer (not shown) connected to the lift support unit 126, and the lift support portion 126 The operation of the workpiece holding device 110, the glass substrate 107 and the control point 123 held by the workpiece holding device 110 are linearly oriented in the Z-axis direction. The lifting of the robot 102 is illustrated in more detail in Figure 11. In the figure, the reference numeral b is a distance indicating a center of rotation of the lift shaft motor 124 to a winding center of a speed reducer (not shown) connected to the lift support portion 126. The reference number b is equal to the distance from the rotation center of the elevation mounting portion 125 to the rotation center of the speed reducer (not shown) to which the lifting shaft motor 124 is coupled. Therefore, the rotation support center 126 rotation center and the rotation center of the lifting shaft motor 124 and the lifting assembly portion 125 are provided. The triangle formed by the connecting line of the center of rotation is an isosceles triangle. The bottom edge z of the isosceles triangle is the distance from the center of rotation of the lifting and fitting portion 125 to the center of rotation of the lifting support portion 126. For example, when the lift shaft motor 124 rotates 2 γ, the angle formed by the lower lift link 112 and the Z-axis zero reference 127, and the angle formed from the Z-axis on the extension line of the upper lift link 111 is γ, and is maintained relative to the body arm support portion. 113 the direction of its Z axis. The amount of lift z is calculated according to the formula (2).

z=2bsin(γ).........(2)

Fig. 12 is a view showing a state in which the robot 102 of Fig. 8 is viewed from the positive Z-axis direction. The winding shaft 130 is coupled to a speed reducer (not shown). This speed reducer is coupled to the winding shaft motor 128 shown in Fig. 8. The winding shaft 130 is coupled to the winding portion 129, and the winding portion 129 is coupled to the body arm supporting portion 113. The rotation of the winding shaft motor 128 rotates the unillustrated speed reducer connected thereto to rotate the winding shaft 130. The rotation of the winding shaft 130 causes the connected winding portion 129 to be wound in the winding positive direction 131 or in the winding negative direction 132.

The flow of performing a continuous substrate conveyance by the above-described robot will be described using Figs. 13 and 14. Fig. 13 is a view showing the state of the robot when the workpiece holding device 110 is inserted into the substrate housing 100 as seen from the positive Z-axis direction. When the workpiece holding device 110 is inserted into the substrate housing cassette 100, the first arm shaft 114 is rotated, and the arm 100 is placed toward the substrate to move the arm in the positive X-axis direction. Since the general support plug 101 is provided at a sufficient interval in advance for the comb-shaped distal end portion of the workpiece holding device 110, the workpiece holding device 110 can be inserted into the gap of the support plug 101. When the substrate holding cassette 133 of the plurality of support pins 134 having the same support pin 101 is inserted into the workpiece holding device 110, the workpiece holding device 110 must be operated to be inserted into the substrate housing cassette 133. When the workpiece holding device 110 is inserted into the substrate housing cassette 133, the substrate housing cassette 133 and the workpiece holding device 110 interfere with each other when the winding portion is wound. Therefore, first, the first arm shaft 114 is rotated until the substrate housing cassette 133 and the workpiece holder are held. The device 110 moves the arm in the negative X-axis direction without interfering with each other. Next, the winding shaft motor 128 is rotated to rotate the winding shaft 130 to wind the winding portion 129. Since the first arm shaft 114 is supported by the winding portion 129, the respective portions connected from the first arm shaft 114 to the workpiece holding device 110 rotate together.

Fig. 14 is a view showing the contraction of the arm by the above operation, the winding portion 129 is wound, and the workpiece holding device 110 is oriented toward the substrate housing 133. Here, when the first arm shaft 114 is rotated, the workpiece holding device 110 is wound in the winding negative direction 132, and the arm holding device 110 is moved to the Y-axis negative direction, the workpiece holding device 110 can be inserted into the substrate housing. 133.

15 to 16 are diagrams showing a state in which the robot 102 transports the glass substrate 107 to any of the plurality of substrate storage cassettes 100 that are stacked in the substrate housing 100. In most cases, a large number of glass substrates 107 are accommodated in a limited area, so that the substrate housing cassettes 100 are plurally stacked. When the substrate accommodating cassette 100 is formed to be stacked, and is calculated in one step, two stages, ..., n stages from the bottom, the substrate is placed on the substrate above the n-th stage substrate housing 135, for example, the second stage substrate housing 匣The n+2 stage substrate accommodates the crucible 136. In Fig. 15, the robot 102 is in a state in which the workpiece holding device 110 can be inserted into the substrate housing cassette 135 by the action of extending the arm. As a result, when the workpiece holding device 110 is inserted into the n+2 stage substrate receiving cassette 136, the lifting shaft motor 124 is rotated to rotate the lifting assembly portion 125 and the lifting support portion 126, and the operation is continued until the workpiece holding device 110 becomes insertable n+2. The position of the segment substrate housing cassette 136 in the Z-axis direction (see Fig. 16). After the Z-axis is operating in the positive direction, the first arm shaft 114 is rotated to extend the arm, and the workpiece holding device 110 is inserted into the n+2-stage substrate housing cassette 136. Fig. 16 is a view showing a state in which the robot inserts the substrate into the n+2 stage substrate storage cassette from the state in which the robot is stacked in the state of Fig. 15 .

The robot 102 having the above configuration is supported by the arm (the first arm link 108 and the second arm 109) by the arm support portion 113. Therefore, the weight of the arm and the weight of the workpiece handling device 110 and the glass substrate 107 cause the arm to face. The direction of gravity is deflected. In recent years, as the size of the glass substrate has increased, the weight of the glass substrate and the workpiece holding device and the arm corresponding to the glass substrate have increased in size, so that the above-described deflection is increased, and the robot workpiece holding device is accurately and quickly inserted into the substrate. Between the glass substrates accommodated in the crucible and the glass substrate held by the workpiece holding device during the telescopic arm, the amount of expansion and contraction of the arm (horizontal movement amount) and the vertical direction opposite to the deflection direction have been developed. A technique for performing correction (see Patent Document 1).

As described above, the conventional workpiece holding device corrects the deflection of the glass substrate and the gravity of the arm and the workpiece holding device.

[Patent Document 1] Japanese Patent Laid-Open Publication No. 2000-183128

The conventional workpiece holding device described in Patent Document 1 corrects the static deflection caused by the gravity of the substrate and the arm. However, most of the robots have a moment of inertia that is subjected to the expansion and contraction of the arm, resulting in a deflection greater than the static deflection.

Next, a state in which the moment of inertia occurs during the arm expansion and contraction operation will be described using Figs. 17 and 18. Fig. 17 is a view showing the state of gravity of the robot when the substrate is held by the workpiece holding device. The figure M is the center of gravity when the workpiece holding device 110 and the glass substrate 107 are included, and the weight is represented by the figure number m (kg). The figure number Xg is the X-axis direction distance from the arm shaft motor 115 to the center of gravity M, and the figure number Zg is the Z-axis direction distance from the arm shaft motor 115 to the center of gravity M. Fig. 18 is a view showing the relationship between the simple center of gravity M of the arm shaft motor 115 shown in Fig. 17. When the arm shaft motor 115 rotates so that the arm is extended in the positive direction of the X-axis by the acceleration α [m/s ² ], a force F1 [N] is generated. F1 is calculated according to the formula (3).

F1=m. α.........(3)

F2 is the force that indicates that F1 causes the center of gravity to take over the reaction. The relationship between F1 and F2 is as shown in the formula (4).

F1=F2.........(4)

The arm shaft motor shaft center position 137 is the center position of the arm shaft motor 115, and the figure N is the moment of inertia N[Nm] generated by the F2 around the arm shaft motor shaft center position 137, which is according to the (5) Calculated by the formula.

N=F2. Zg.........(5)

It is desirable that the arm parts of the robot and the workpiece holding device are close to a completely rigid body. However, in many cases, in order to reduce the load and reduce the cost, the strength of the member is lowered, and the rigidity is close to a completely rigid body. In addition to the condition of approaching a completely rigid body, the moment of inertia N causes deflection of the arm parts and the workpiece holding device.

Fig. 19 is a view showing the deflection of each arm portion and the workpiece holding device when the arm is extended in the positive X-axis direction. As described using Fig. 18, the moment of inertia is applied counterclockwise in the drawing centering on the first arm shaft 114. The first arm link 108 is deflected counterclockwise in the drawing due to the moment of inertia. Therefore, the second arm shaft 118 is displaced counterclockwise from the center of the first arm shaft 114 from the position when the second arm shaft 118 is completely rigid. The second arm link 109 is deflected in the counterclockwise direction in the drawing centering on the second arm shaft 118 due to the moment of inertia. The flange 122 is displaced counterclockwise from the center of the second arm shaft 118 from the position when it is completely rigid. The workpiece holding device 110 is deflected counterclockwise in the drawing centering on the flange 122 due to the moment of inertia. The ideal control point 139 is the position of the control point when the arm is completely rigid, but the influence of the above moment of inertia causes the position of the center of gravity to flex, and as a result, the control point also deviates from the position shown as the control point 138, so that the Z-axis direction The amount of deviation is ΔZ1.

The first 20 shows the relationship from the arm shaft 115 of the motor shown in FIG. 17 of the center of gravity M of the simple pattern, acceleration α [m / s ^2] is contracted in the X-axis negative direction, and thus the force F3 [N] generated status. The parallel force F3 is calculated based on the same equation (6) as the equation (3).

F3=m. α.........(6)

Figure F4 is the parallel force caused by F3 causing the center of gravity to take over the reaction. The relationship between F3 and F4 is as shown in the equation (7).

F3=F4.........(7)

The arm shaft motor shaft center position 137 is the center position of the arm shaft motor 115, and the figure N is the moment of inertia N[Nm] generated by the F4 around the arm shaft motor shaft center position 137, which is according to the (8) Calculated by the formula.

N=F4. Zg.........(8)

Fig. 21 is a view showing the deflection of each arm portion and the workpiece holding device when the arm is contracted in the negative direction of the X-axis. As described using Fig. 20, the moment of inertia is applied clockwise in the drawing centering on the first arm shaft 114. The first arm link 108 is deflected clockwise in the drawing due to the moment of inertia. Therefore, the position of the second arm shaft 118 is shifted clockwise from the position of the first arm shaft 114 from the position where the second arm shaft 118 is completely rigid. The second arm link 109 is bent clockwise in the drawing centering on the second arm shaft 118 due to the moment of inertia. Thus, the flange 122 is offset clockwise from the position of the second rigid shaft 118 from the position when it is completely rigid. The workpiece holding device 110 is deflected clockwise in the drawing centering on the flange 122 due to the moment of inertia. The ideal control point 139 is the position of the control point when the arm is completely rigid, but the influence of the above moment of inertia causes the position of the center of gravity to flex, and as a result, the control point also deviates from the position shown by the control point 140, so that the Z-axis direction The amount of deviation is ΔZ2.

Fig. 22 is a view showing the relationship between the amount of deflection of the arm shaft motor and the position of the control point and the time when the robot moves the arm in the positive X-axis direction. The horizontal axis t represents time, the vertical axis v represents the velocity, and the vertical axis represents the amount of deflection in the Z-axis direction indicating the position of the control point. When the robot moves the arm in the positive direction of the X-axis, the arm-axis motor forms a waveform speed indicated by the arm-axis motor speed 143. When the arm is accelerated in the positive direction of the X-axis, the arm shaft motor 115 is accelerated as indicated by the arm shaft motor speed 143, generating a moment of inertia as described above, causing the control point to deviate in the positive direction of the Z-axis. The temporal transition of the amount of deviation at this time is represented by the amount of deflection 144 of the position of the control point at the time of acceleration. When the arm is decelerated from the normal speed in the positive direction of the X-axis, the arm shaft motor 115 is decelerated from the normal speed as indicated by the arm shaft motor speed 143, and the moment of inertia is generated as described above, causing the control point to deviate in the negative direction of the Z-axis. . The temporal transition of the amount of deviation at this time is expressed by the amount of deflection 145 of the position of the control point at the time of acceleration.

The deflection of the arm during expansion and contraction due to the above-described causes causes the workpiece holding device of the robot to enter and exit between the substrates accommodated in the substrate housing cassette, and when the substrate held by the workpiece holding device enters and exits, and when entering and exiting the substrate processing portion Interference in various parts may cause damage to the substrate. In this case, it is conceivable to widen the interval between the substrate in which the substrate is accommodated, or to reduce the acceleration and deceleration of the arm expansion and contraction in order to reduce the moment of inertia. However, the number of substrates to be accommodated is reduced, and the substrate carrying time is lengthened. Unfavorable conditions. In addition, it is also conceivable to prepare an operation program that can finely control the movement of the robot in advance so that the deflection when the arm is stretched and contracted does not interfere with the substrate housing or the substrate processing portion, but the deflection of the arm when it is stretched and contracted may be caused by the workpiece holding device or Since the weight and center of gravity of the glass substrate to be held vary, the previously prepared operation program must be completely remade when the workpiece holding device or the glass substrate to be held is changed. In recent years, based on the fact that glass substrates are becoming larger, and the demand for liquid crystal or plasma displays is increasing, the production speed is required to be faster, so that the above-mentioned deflection tends to increase.

The present invention has been made in view of the above-described problems, and an object of the invention is to provide a robot apparatus that can prevent a glass substrate from entering and exiting a substrate housing and a substrate processing unit without reducing the acceleration and deceleration of the arm stretching operation.

In order to solve the above problems, the present invention is constituted as follows.

According to a first aspect of the invention, there is provided a workpiece transporting apparatus comprising: a robot having an arm having a tip holding a workpiece gripping device for holding or placing the workpiece, and an arm for allowing the arm to expand and contract in a horizontal direction a shaft motor and a lifting shaft motor for lifting the arm; and a control device capable of driving and controlling the arm shaft motor and the lifting shaft motor of the robot, wherein the correction means is provided according to the above The arm shaft motor drives the horizontal direction movement acceleration/deceleration at the time of the expansion and contraction of the arm to calculate the engagement force, and calculates the moment generated by the inertial force of the parallel force from the vertical direction of the workpiece center of gravity, according to the arm from the arm And a torque value of the workpiece holding device is calculated by removing a torque of a force generated by the inertial force, and a deflection amount in a vertical direction of the robot control point position is calculated, and the lifting shaft motor is driven by the deflection amount and is performed at a predetermined control cycle. The processing of the vertical direction correction of the above robot.

The invention of claim 2, wherein the control device includes a storage means for registering robot information of the robot and a workpiece of the workpiece holding device Holding device information; workpiece information of the workpiece; and other parameters, which are calculated based on the above parameters.

The invention of claim 3, wherein the workpiece handling device according to claim 1 or 2, wherein the number of the workpiece holding devices is assigned to each of the holding device identification members to identify the holding device The workpiece holding device information is registered in association with each other, and when the deflection amount is calculated, the deflection amount is calculated based on the workpiece holding device information retrieved by the gripping device identifier.

The invention of claim 4 is the workpiece handling device of claim 1 or 2, wherein the workpiece identification member is assigned to the plurality of workpieces to associate the workpiece identification member with The workpiece information is formed and registered, and when the amount of deflection is calculated, the amount of deflection is calculated based on the workpiece information retrieved by the workpiece identifier.

According to a fifth aspect of the invention, in the workpiece handling device of the first aspect of the invention, the robot is a horizontal articulated robot for transporting a liquid crystal glass substrate.

According to the above configuration, the control device of the present invention calculates the arm deflection caused by the moment of inertia when the robot arm having the arm and the lifting shaft is operated, and the position of the control point position deviation formed by the deflection causes the lifting shaft to face the Z The axial direction motion corrects the position of the control point, whereby the vertical trajectory of the control point can be kept constant.

[Best Embodiment of the Invention]

Hereinafter, embodiments of the present invention will be described with reference to the drawings.

(First embodiment)

The present invention will be described with respect to a workpiece transporting apparatus having a horizontal articulated robot equipped with a vertical lifting shaft, having the configuration shown in Figs. 7 and 8.

The parameters of the robot 102 are input in advance to the storage means (not shown) provided in the control device 104. The robot information is registered in the above storage means: the distance [m] of the first arm shaft 114 to the second arm shaft 118 shown in FIG. 8; the distance [m] of the second arm shaft 118 to the flange 122; the arm shaft motor 115 to The Z-axis direction distance [m] of the flange 122; the distance [m] of the lifting assembly portion 125 to the lifting shaft motor 124; and the distance [m] of the lifting shaft motor 124 to the lifting support portion 126, and the registration of the workpiece holding device information: The weight of the workpiece holding device [kg]; the distance from the flange 122 of the workpiece holding device to the X-axis direction of the workpiece center of gravity M [m]; the distance from the flange 122 of the workpiece holding device to the Z-axis direction of the workpiece center of gravity M [m]; The distance from the flange 122 of the gripping device to the X-axis direction of the control point [m]; the distance from the flange 122 of the workpiece holding device to the Y-axis direction of the control point [m]; and the flange 122 of the workpiece holding device to the control point Z Axis direction distance [m], and registered workpiece information: the weight of the workpiece to be gripped [kg]; the distance from the flange 122 of the workpiece control point to be held to the X-axis direction of the workpiece center of gravity M [m]; and the workpiece control to be held The distance from the flange 122 of the point to the Z-axis direction of the center of gravity M of the workpiece [m], and the registered workpiece and the workpiece holding device Rigidity K [Nm / rad], and registration control means outputs an operation command to the control cycle of the motor during each instruction cycle time [s] of all parameters.

When the workpiece holding device or the workpiece is present in plural, an identification member such as a unique number (a gripping device identifier and a workpiece identifier) is assigned to each of the workpiece holding devices, and the above parameters are registered for each of the identification members. These parameters are used for calculations during the action, but they are retrieved by the identifier.

The parameters are input by pressing a button provided in the teaching means 106. However, this parameter is a storage means stored in the control device 104 by means of a communication means or the like by an external memory means (not shown). In addition, other parameters are required to achieve the desired operation and control of the workpiece handling device, but the description of the parameters is omitted irrespective of the present invention.

The robot 102 inputs an operation command via the cable 105 to the control device 104 based on an operation program stored in advance in the storage means or by pressing a plurality of buttons having the teaching means 106, and then transmits the cable to the respective motors via the cable 103. Perform the action.

The operation of the robot having the plural axes to which the present invention is applied will be described using the flowchart of Fig. 1.

The operation program stores the number (identification) of the workpiece holding device required for the operation and the workpiece number (identification) held by the workpiece. First, in order to allow the specified action program to execute the action, the work program is selected, and the parameters referred to by the identifier included in the work program are retrieved and read.

On the other hand, when the teaching means for operating the robot 102 is operated by the teaching means, when the button having the teaching means 106 is pressed and the operation command is input to the control device 104 via the cable 105, the workpiece holding device is conveyed. The number (identification) and the workpiece number (identification) that it holds during the action.

The distance from the flange 122 to the center of gravity M of the workpiece M in the X-axis direction [m] and the distance in the Z-axis direction [m] are the distances from the flange 122 of the workpiece holding device to the X-axis direction of the center of gravity M required for the operation [m] And the distance from the flange 122 of the workpiece holding device to the Z-axis direction of the center of gravity M [m], and the distance from the flange 122 of the workpiece to the X-axis direction of the center of gravity M during operation [m], and the movement time The distance from the flange 122 of the workpiece to the center of gravity M in the Z-axis direction [m] is calculated.

The distance from the first arm shaft 114 to the flange 122 in the X-axis direction after the control unit outputs a predetermined control period of one cycle of the control command to each motor is the first arm shaft 114 to the second arm stored in advance in the storage means. The distance [m] of the shaft 118 and the distance [m] of the second arm shaft 118 to the flange 122 are geometrically calculated. For example, in the arm state including the mechanisms shown in FIGS. 8 , 9 , and 10 , the X-axis direction distance between the first arm shaft 114 and the flange 122 can be calculated according to the above formula (1). Further, since the first arm shaft 114 and the arm shaft motor 115 are disposed at the same position in the X-axis direction, the X-axis direction distance [m] of the first arm shaft 114 to the flange 122 is equal to the arm shaft motor 115 to the flange. 122 is in the X-axis direction distance [m].

(Step 1) Adding the distance [m] in the X-axis direction of the flange 122 to the center of gravity M of the workpiece and the distance [m] in the X-axis direction of the arm shaft motor 115 to the flange 122, and then outputting 1 to each motor to the slave control device The distance from the arm axis motor 115 to the workpiece center of gravity M in the X-axis direction [m] after the operation command of the cycle amount, and the distance from the flange 122 to the Z-axis direction of the workpiece center of gravity M [m] and the arm shaft motor previously stored in the storage means The distance from the 115 to the Z-axis direction distance [m] of the workpiece center of gravity M is calculated, and the Z-axis direction distance [m] of the arm shaft motor 115 to the workpiece center of gravity M after the one-cycle operation command is output from the control device for each motor is calculated. .

(Step 2) The X-axis direction distance from the first arm shaft 114 to the flange 122 before the operation command for outputting one cycle of the amount of the motor from the control device is the first arm shaft 114 to the second arm stored in advance in the storage means. The distance [m] of the shaft 118 and the distance [m] of the second arm shaft 118 to the flange 122 can be calculated geometrically. For example, in the arm state including the mechanisms shown in FIGS. 8 , 9 , and 10 , the X-axis direction distance between the first arm shaft 114 and the flange 122 can be calculated according to the above formula (1).

As described above, by adding the distance [m] in the X-axis direction of the flange 122 to the center of gravity M of the workpiece and the distance [m] in the X-axis direction of the arm shaft motor 115 to the flange 122, it is possible to calculate the output of each motor from the control device. The distance from the arm axis motor 115 before the operation command of the cycle amount to the X-axis direction distance [m] of the workpiece center of gravity M.

(Step 3) The difference in the X-axis direction distance [m] between the arm shaft motor 115 and the workpiece center of gravity M calculated in steps 1 and 2 is calculated. That is, the X-axis direction moving distance of the workpiece center of gravity M is calculated.

(Step 4) The acceleration/deceleration α is calculated by dividing the X-axis direction moving distance of the center of gravity calculated in Step 3 by the cycle time [s] when the control device stored in the storage means outputs the operation command for each motor. [m/s ² ].

(Step 5) The weight [kg] of the workpiece holding device required for the operation of the control device and the weight [kg] of the workpiece held during the operation are added, and the total weight of the front end portion of the flange 122 is calculated. Based on the acceleration/deceleration α [m/s ² ] calculated in step 4, the parallel force F[N] is calculated by the equation (9).

F=m. α.........(9)

(Step 6) The Z-axis direction distance [m] of the arm shaft motor 115 to the center of gravity M after the one-cycle operation command is output from the control device calculated in the first step, and the parallel force F calculated in the step 5 is used. The reaction force of [N] (the value is equal to the parallel force F), and the moment of inertia N[Nm] is calculated according to the formula (10).

N=F. Zg.........(10)

(Step 7) Using the rigidity value K [Nm/rad] on the workpiece holding device in the gripping state during the operation and the moment of inertia N[Nm] calculated in the step 6, the deflection angle is calculated according to the formula (11). [rad].

The angle of deflection calculated here It is shown in Figures 2 and 3. Figure 2 shows the deflection angle when the arm is moving in the positive direction of the X-axis. 1. Figure 3 shows the deflection angle when the arm moves in the negative direction of the X axis. 2. When the center of the winding of the first arm shaft 114 and the respective portions of the arm and the workpiece holding device 110 are completely rigid, when the intersection point of the straight line whose control point is parallel to the workpiece holding device 110 is P point, the deflection angles are respectively the following two The angle formed by the straight line, that is, the straight line passing through the P point and the control point, and the angle formed by the connecting line of the control point 138 and the point P at which the arm portions and the deflection of the workpiece holding device 110 are deviated.

Deflection angle When the center of the winding of the first arm shaft 114 and the parts of the arm and the workpiece holding device 110 are completely rigid, when the intersection point of the line whose center of gravity is parallel to the workpiece holding device 110 is P point, it is equal to the following two lines. The angle formed, that is, the straight line passing through the P point and the center of gravity position 141, and the angle formed by the center of gravity 142 and the connecting line of the point P at which the deflection of the arm portions and the workpiece holding device 110 are deviated.

(Step 8) The distance [m] of the first arm shaft 114 to the second arm shaft 118 stored in advance in the storage means, and the distance [m] of the second arm shaft 118 to the flange 122, and the arm shaft motor 115 are used. The angle is calculated geometrically in the X-axis direction distance (arm extension length) of the first arm shaft 114 to the flange 122 after the control device outputs an operation command for one cycle of each motor. For example, in the arm state including the mechanisms shown in FIGS. 8 , 9 , and 10 , the X-axis direction distance between the first arm shaft 114 and the flange 122 can be calculated according to the above formula (1).

(Step 9) The length of the arm expansion and contraction calculated in the step 8 is added to the distance from the flange 122 of the workpiece holding device to the X-axis direction of the control point [m], and the distance R from the first arm shaft 144 to the control point is calculated. ], using the deflection angle calculated in step 7 [rad] Calculate the amount of deflection ΔZ [m]. The amount of deflection ΔZ [m] is calculated according to the formula (12).

(Step 10) Considering each part of the arm as a completely rigid body, geometrically calculating the amount of lifting and lowering of the lifting shaft [m] after outputting an operation command for each motor from the control device for one cycle, and controlling the flange 122 of the workpiece holding device to the control The Z-axis direction distance [m] of the point and the above-described lifting amount [m] are added, and the control point Z-axis direction position [m] after the control device outputs an operation command for one cycle of each motor is calculated, and step 9 is subtracted. The calculated deflection amount [m] is regarded as the corrected target control point Z-axis direction position Zc[m].

(Step 11) After the control device outputs an operation command for one cycle for each motor, the distance [m] stored in the elevating attachment portion 125 of the storage means to the elevating shaft motor 124 and the elevating shaft motor 124 to the elevating support portion are used. The distance [m] of 126 is geometrically calculated for each motor angle of the lift shaft when the lift target is operated only in the corrected target control point Z-axis direction position Zc [m] calculated in step 10. For example, the distance between the elevating attachment portion 125 of the storage means 125 to the elevating shaft motor 124 and the distance between the elevating shaft motor 124 and the elevating support portion 126 are stored in advance in the state of the elevating shaft provided by the mechanism shown in Fig. 11 [m]. When the value is b, the lifting shaft motor angle γ of the lifting shaft that moves toward the corrected target control point Z-axis direction position Zc [m] is the equation (13) according to the equation (2) Calculated.

γ=asin(Zc/2b)............(13)

(Step 12) The operation command corresponding to the lift shaft motor angle γ calculated in the step 11 is regarded as a new lift shaft motor operation command, and is output to the respective shaft motors of the robot via the cable 103.

According to the above processing, the operation command output to each motor is a corrected operation command, and as a result, the target control point position is corrected. Fig. 4 is a view showing the relationship between the speed 143 of the arm shaft motor when the robot moves the arm in the positive direction of the X-axis, and the position and time of the control point, and the correction amount, as shown in Fig. 22. The horizontal axis t represents time, the vertical axis v represents velocity, and the vertical axis Z represents Z-axis deflection amounts 144 and 145 indicating control point positions. The correction amount is equal to the number of the deflection amount ΔZ calculated in step 9. The correction amount when the arm is accelerated in the positive direction of the X-axis is the correction 13 at the time of acceleration, and the arm is decelerated in the positive direction of the X-axis. The correction amount is the correction 14 at the time of deceleration.

Fig. 5 is a view showing a state of correction of the amount of deflection ΔZ when the arm is accelerated in the positive direction of the X-axis. Since the added amount of the deflection amount ΔZ and the correction amount becomes zero, the corrected control point 15 and the ideal control point 138 are positioned in the Z-axis direction, and the position of the control point in the Z-axis direction is kept constant. Further, Fig. 6 is a view showing a state of correction of the amount of deflection ΔZ when the arm is accelerated in the negative direction of the X-axis. Since the added amount of the deflection amount ΔZ and the correction amount is zero, the corrected control point 16 and the ideal control point 139 are positioned in the Z-axis direction, and the position of the control point in the Z-axis direction is kept constant.

By performing the continuous processing flow on the output cycle of the operation command of the control device, it is possible to often correct the deflection caused by the moment of inertia in the vertical direction. In addition, since the correction of the deflection is not complicated as in the embodiment, the microcomputer included in the control device that executes the robot control can shorten the calculation time, and thus does not affect the motion control processing of the robot. .

Further, when a plurality of substrates are housed and mixed in a plurality of glass substrates having different weights, different operation programs of the workpiece identification members (numbers) to be held are prepared, and the operation sequence of the glass substrate to be held can be performed without generating a moment of inertia. The deflection is carried out on the glass substrate.

The above is an example of the implementation of the present invention. The arm may be, for example, a linear motion shaft composed of a motor and a rack & pinion or a ball screw, or may be a direct force of air pressure or oil pressure controlled by a solenoid valve. The moving shaft may be configured such that the first arm shaft 114, the second arm shaft 118, and the flange 122 are respectively provided with motors to form individual windings, and can be inserted in the X-axis direction, and can be oriented in the Y-axis direction and Z. The axis moves. In this case, the arm may have a mechanism that can be linearly inserted into the X-axis direction.

In addition, the lifting shaft may be, for example, a linear motion shaft composed of a rack/pinion gear or a ball screw, or may be a linear motion shaft that is powered by a solenoid valve controlled air pressure or oil pressure, or may be configured as a lifting shaft. In addition to the motor 124, the lift attachment portion 125 and the elevation support portion 126 are provided with motors to form individual windings, and can be inserted in the Z-axis direction and can be operated in the X-axis direction and the Y-axis direction. In this case, the lifting shaft may have a mechanism that can be linearly inserted into the Z-axis direction. 7 and 8 and 12 and 13 are examples showing a general device, but it is not necessary to have a winding shaft 130.

Further, the teaching means 106 described in FIG. 7 includes an external memory device (not shown), but the teaching means 106 may be, for example, a general-purpose computer or a personal computer including an external memory device. Further, when the storage means stores an operation program in advance, the teaching means 106 may not be provided. The cable 105 described in FIG. 7 is a wired transmission indicating electrical connection. However, it may be configured as a wireless means using radio waves, for example.

The present invention is also applicable to a vertical six-axis articulated robot used in most industrial robots, for example, a robot that can be applied to degrees of freedom in the horizontal direction and the vertical direction. For example, for the purpose of gripping between presses, it is necessary for the continuous action press to carry the workpiece at high speed and correctly. Since the workpiece loading port of the press is formed to the minimum limit when the workpiece is loaded, the deflection caused by the moment of inertia at the time of high-speed conveyance can be said to cause the workpiece and the press to interfere with each other. However, when the present invention is applied, the amount of deflection generated during the conveyance of the workpiece is calculated, and the calculated deflection amount is utilized in the direction in which the position is completely deflected from the respective portions due to the deflection. The linear interpolation of the degree of freedom eliminates the amount of linear deflection.

[Industrial availability]

The present invention is applicable to a transportation application in which a long stroke operation is performed at a high speed and is caused by actuating deflection, and in particular, it can be applied to a case where one end is operated and the other end is conveyed.

13. . . Time-varying correction amount when the arm is accelerated in the positive direction of the X-axis

14. . . Time-lapse of correction when the arm is decelerating in the positive direction of the X-axis

15. . . Corrected control point when the arm is accelerated in the positive direction of the X axis

16. . . Corrected control point when the arm is decelerating in the positive direction of the X axis

100. . . Substrate storage

101. . . Support pin

102. . . robot

103. . . Cable

104. . . Control device

105. . . Cable

106. . . Teaching means

107. . . glass substrate

108. . . First arm link

109. . . 2nd arm link

110. . . Workpiece holding device

111. . . Upper lifting link

112. . . Lower lift link

113. . . Body arm support

114. . . First arm shaft

115. . . Arm shaft motor

116. . . Arm shaft reducer

117. . . 1st link belt

118. . . 2nd arm shaft

119. . . 2nd arm shaft reducer

120. . . 2nd link belt

121. . . Flange reducer

122. . . Flange

123. . . Control point

124. . . Lifting shaft motor

125. . . Lifting assembly

126. . . Lifting support

127. . . Z-axis zero reference

128. . . Winding shaft motor

129. . . Winding

130. . . Circumferential axis

131. . . Swirling the positive direction

132. . . Swiveling the negative direction

133. . . Substrate storage

134. . . Support pin

135. . . The nth stage substrate housing

136. . . The n+2th substrate is accommodated匣

137. . . Arm shaft motor shaft center position

138. . . Deviation control point (when the arm accelerates in the positive direction of the X axis)

139. . . Ideal control point

140. . . Deviation control point (when the arm accelerates in the negative direction of the X axis)

141. . . Ideal control point

142. . . Deviated center of gravity

143. . . Arm shaft motor speed

144. . . Control point position deflection at acceleration

145. . . Deflection of control point position during deceleration

Figure 1 is a flow chart of the present invention.

Figure 2 shows the deflection angle of the arm when it is moving in the positive direction of the X axis. 1 form a map.

Figure 3 shows the deflection angle of the arm when it moves in the negative direction of the X axis. 2 form a map.

Fig. 4 is a diagram showing the relationship between the speed of the arm shaft motor and the position of the control point, the correction amount, and the time when the arm is moved in the positive direction of the X-axis.

Fig. 5 is a state of correction of the amount of deflection ΔZ when the arm is accelerated in the positive direction of the X-axis.

Fig. 6 is a state of correction of the amount of deflection ΔZ when the arm is accelerated in the negative direction of the X-axis.

Fig. 7 is a view showing the configuration of a workpiece handling device.

Figure 8 is a diagram of the robot composition.

Figure 9 is a diagram showing the state of the robot arm extension.

Figure 10 is a diagram of the contraction state of the robot arm.

Figure 11 is a diagram of the robot's lifting state.

Fig. 12 is a view showing the configuration of the robot when the robot is viewed from above.

Fig. 13 is a view showing the positional relationship between the robot and the substrate housing cassette which are subjected to the expansion and contraction operation in the X-direction substrate housing.

Fig. 14 is a view showing the positional relationship between the robot and the substrate housing cassette which are subjected to the expansion and contraction operation in the Y-direction substrate housing.

Fig. 15 is a view showing a state in which the robot inserts the workpiece holding device for the nth stage of the plurality of substrate housing cassettes.

Fig. 16 is a view showing a state in which the robot inserts the workpiece holding device for the nth stage of the plurality of substrate housing cassettes.

Fig. 17 is a view showing a center of gravity when the workpiece holding device holds the glass substrate.

Figure 18 is a diagram showing the moment of inertia when the arm is moving in the positive direction of the X-axis.

Figure 19 is a deflection diagram of the arm as it moves in the positive direction of the X-axis.

Figure 20 is a diagram showing the moment of inertia when the arm is moving in the negative direction of the X-axis.

Figure 21 is a deflection diagram of the arm as it moves in the negative direction of the X-axis.

Fig. 22 is a graph showing the relationship between the speed of the arm shaft motor and the amount of deflection of the control point position and time when the arm is moved in the positive direction of the X-axis.

15. . . Corrected control point when the arm is accelerated in the positive direction of the X axis

108. . . First arm link

109. . . 2nd arm link

110. . . Workpiece holding device

111. . . Upper lifting link

112. . . Lower lift link

114. . . First arm shaft

118. . . 2nd arm shaft

122. . . Flange

124. . . Lifting shaft motor

125. . . Lifting assembly

126. . . Lifting support

139. . . Ideal control point

Claims (5)

A workpiece transporting apparatus including: a robot having an arm equipped with a workpiece gripping device for holding or placing a workpiece at a tip end, and an arm shaft motor that can expand and contract the arm in a horizontal direction, and a lifting and lowering of the arm a shaft motor; and a control device capable of driving and controlling the arm shaft motor and the lift shaft motor of the robot, wherein the correction means is provided by the arm shaft motor driving the arm to expand and contract Calculating the parallel force in the horizontal direction movement acceleration/deceleration of the workpiece center of gravity, and calculating the moment generated by the inertial force in the vertical direction from the center of gravity of the workpiece, and removing the rigidity from the arm to the workpiece holding device The torque of the force generated by the inertial force is calculated by the amount of deflection in the vertical direction of the robot control point position, and the lifting shaft motor is driven by the deflection amount and corrected in the vertical direction of the robot at predetermined control cycles. The workpiece transfer device according to claim 1, wherein the control device includes a storage means for registering robot information of the robot, information of a workpiece holding device of the workpiece holding device, and workpiece information of the workpiece; And other parameters, which are calculated based on the above parameters. The workpiece conveying device according to the first or second aspect of the invention, wherein the plurality of gripping device identification devices are associated with the gripping device identification member to associate the workpiece gripping device information with the workpiece gripping device. Log in, when calculating the above deflection amount, according to the above The amount of deflection is calculated by the workpiece holding device information retrieved by the device identifier. The workpiece transfer device according to the first or second aspect of the invention, wherein the workpiece identifier is assigned to each of the plurality of workpieces, and the workpiece information is associated with the workpiece information, and the scratch is calculated. At the time of the curvature, the amount of deflection is calculated based on the workpiece information retrieved by the workpiece identifier. The workpiece transfer device according to the first aspect of the invention, wherein the robot is a horizontal articulated robot for transporting a liquid crystal glass substrate.