JP4151123B2 - Work following device - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a workpiece follower that enables a work to be performed while following a workpiece, and more particularly, to a workpiece follower that can perform a highly accurate work.
[0002]
[Prior art]
In an automobile production factory, in order to perform an efficient work, a follower is used that allows the work to be carried out while following the conveyed vehicle body. On this follow-up device, a production machine such as a robot that operates on the vehicle body is placed.
[0003]
[Problems to be solved by the invention]
In such a conventional follower device, the follower device performs the follower to the vehicle body, and the work to the vehicle body is performed by a production machine such as a robot. Was dependent on the performance of.
[0004]
However, in recent years, it has become necessary to install parts with extremely high work accuracy using a tracking device, and making it possible for a mounted production machine to follow a vehicle body with very high accuracy Considering the improvement of the performance of the device, it has become very difficult.
[0005]
The cause is as follows.
(1) First, heavy objects such as car bodies are often transported by chain conveyors, etc., and the transport distance is long, so the transport speed of the car body can be seen microscopically due to slack in the chain. Fluctuates periodically.
(2) Next, the worker repeatedly gets on and off the vehicle body in order to attach components to the vehicle body, but this becomes a load fluctuation, and the conveyance speed of the vehicle body fluctuates irregularly.
(3) Many production machines such as robots placed on the follower are very heavy.
[0006]
It is very difficult to accurately follow the vehicle body whose conveyance speed fluctuates periodically or irregularly while placing such a heavy object, even if the control responsiveness is improved.
[0007]
Conventionally, work with very high accuracy has not been required. However, when working with high accuracy, fluctuations in the relative speed between the transport speed of the vehicle body and the tracking speed of the tracking device, which are viewed microscopically, greatly affect the accuracy of the work. To do.
[0008]
In order to always set the relative speed to 0, it is necessary to use a motor with a large power for the tracking device or to perform special control in which the fluctuation of the relative speed is predicted in advance, which increases the size and cost of the tracking device. A problem occurs. Not only that, if the tracking device itself is controlled to accurately follow the vehicle body, the mounted robot and other production machines will always vibrate, and the robot arm etc. is insufficiently rigid. The work tip portion vibrates and eventually the work requiring high accuracy cannot be performed. In order to prevent vibration, it is only necessary to further increase the rigidity of the robot. However, this causes a vicious circle in which the weight increases and the follower becomes larger.
[0009]
The present invention has been made to solve such a conventional problem, and an object of the present invention is to provide a work follower that enables high-precision work while following a work.
[0010]
[Means for Solving the Problems]
In order to achieve the above object, the present invention is configured as follows.
The invention according to claim 1 is detected by a workpiece conveyance means for conveying a workpiece, a workpiece conveyance speed detection means for detecting a conveyance speed of a workpiece conveyed by the workpiece conveyance means, and the workpiece conveyance speed detection means. First follow-up means for following the workpiece at an average carrying speed based on the carrying speed; and the first following means The relative speed is calculated from the following speed detecting means for detecting the following speed when the workpiece is following the workpiece, the conveying speed detected by the workpiece conveying speed detecting means, and the following speed detected by the following speed detecting means. Relative speed calculating means for Relative Relative speed calculated by speed calculation means In response to the To be the same conveyance speed as the workpiece conveyance speed And a second follower attached to the first follower for following the work.
[0011]
The invention described in claim 2 2. The work following apparatus according to claim 1, wherein the first following means is a parallel running means installed so as to be able to run together with the work carried by the work carrying means, and the conveyance detected by the work conveyance speed detecting means. And movement control means for controlling the movement of the parallel means according to the speed. This is a workpiece follower characterized by that.
[0012]
The invention according to claim 3 is the claim 1 In the workpiece follower according to claim 1, 2 The following means Positioning means attached to the first tracking means so as to follow the workpiece within a certain range, and the positioning means to make the relative speed that changes every moment calculated by the relative speed calculation means zero. Position control means for controlling the position of It is composed of
[0013]
The invention according to claim 4 is the claim 3 In the work following apparatus according to claim 2, the second following means The weight of the alignment means possessed by is lighter than the weight of the parallel running means possessed by the first follow-up means. It is characterized by that.
[0016]
【The invention's effect】
The present invention configured as described above has the following effects.
Claim 1, 2 In the invention described in 1 above, the first follower means The Second tracking means by following the workpiece at the average transport speed The work The same transport speed as Since the work is followed by the two follow-up means, the first follow-up means can be followed more accurately by simple control without increasing the size of the first follow-up means.
[0017]
Claim 3 In the invention described in 1 above, the first follower means The Second tracking means by following the workpiece at the average transport speed Makes it follow so that the relative position with the work becomes constant, Since the workpiece is caused to follow by the two following means, it is possible to follow the work more accurately by simple control without increasing the size of the first following means.
[0018]
Claim 4 In the invention described in 2, the second Has tracking means Since the weight of the positioning means is lighter than the weight of the parallel running means included in the first tracking means, the positioning means can follow the workpiece relatively easily without increasing the rigidity of the positioning means. become.
[0019]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, an embodiment of the present invention will be described in detail with reference to the drawings.
FIG. 1 is a schematic configuration diagram of a glass mounting apparatus to which the work following apparatus of the present invention is applied. Moreover, FIG. 2 is a block diagram of the glass attachment part of a glass attachment apparatus.
[0020]
The vehicle body 10 as a workpiece shown in FIG. 1 is slowly conveyed in the right direction in the figure by a chain conveyor which is a workpiece conveying means. Since this chain conveyor is driven by a motor, the conveyance speed of the vehicle body 10 is detected using an encoder attached to the motor. This encoder functions as a conveyance speed detection means.
[0021]
On the conveyance path of the vehicle body 10, a glass attachment device 20 that performs an operation of attaching glass to the rear and front of the vehicle body 10 is provided.
[0022]
The glass attachment device 20 includes a rail 21 provided on the conveyance path of the vehicle body 10 along the conveyance path, and a rail 22 that moves the rail 21 parallel to the conveyance path. A tracking device 23 that follows the vehicle body 10 is attached to be freely movable. In addition, a glass attachment portion 25 is attached to the distal end portion of the arm 24 included in the tracking device 23. In other words, the glass attachment device 20 includes the rails 21 and 22, the follower device 23, and the glass attachment portion 25.
[0023]
The follower 23 is suspended from the rail 21 and travels on the rail 21 by a motor (not shown). The tracking device 23 includes a distance measuring sensor A (detects the distance from the vehicle body to know the relative position) or a speed sensor B (knows the relative position from the relative speed with respect to the vehicle body) that detects the relative position to the vehicle body 10. It is attached. The distance measuring sensor A is a sensor for detecting a deviation from the vehicle body 10 from the distance from the hood of the vehicle body 10, and the speed sensor B is a relative speed with respect to the vehicle body 10 based on the light reflected on the vehicle body 10. It is an optical sensor for detecting. Although the case where two sensors are attached is illustrated in the figure, one of the sensors may be used in practice.
[0024]
In this case, the distance measuring sensor A functions as a relative position detecting means, and the speed sensor B functions as a relative speed detecting means. Further, without using a sensor, the follow-up speed of the follow-up device 23 is calculated based on an encoder attached to the motor of this device, and the relative speed is calculated by the control device from the transfer speed of the chain conveyor and the follow-up speed of the follow-up device 23. It may be calculated. In this case, the encoder functions as a follow-up speed detection means, and the control device also functions as a relative speed calculation means.
[0025]
The follower 23 travels on the rail 21 based on a signal from the encoder of the chain conveyor and follows the vehicle body 10. The following device 23 functions as a parallel running means constituting the first following means, and the follow-up to the vehicle body 10 is performed at an average speed calculated based on a signal from the encoder. This control is performed by a control device, which will be described later, provided exclusively as a movement control means.
[0026]
In a transport apparatus that transports heavy objects such as a chain conveyor, the transport speed fluctuates at a speed that combines periodic fluctuations and irregular fluctuations when viewed microscopically. Since the follower 23 is very heavy, it is impossible to follow such microscopic fluctuations. For this reason, in the present invention, the follower 23 is caused to follow at the average transport speed of the vehicle body 10. When such control is performed, a relative speed is generated between the vehicle body 10 and the tracking device 23. The distance sensor A and the speed sensor B described above detect the relative speed instead of the relative position. Yes, it is the glass mounting portion 25 described later that absorbs the relative speed.
[0027]
As shown in FIGS. 1 and 2, the glass attachment portion 25 is attached to the distal end portion of the arm 24, and the glass G attached to the vehicle body 10 is adsorbed by the adsorption board 30, and the operator handles the handle 31. The glass can be attached as shown in FIG. 1 while moving the posture of the glass G.
[0028]
Since the structure of the mechanism for changing the glass posture in the glass attachment portion 25 is not particularly related to the present invention, a rough structure will be described although it will not be described in detail.
[0029]
The glass turning shaft 32 is an axis for moving one end of the glass G so as to draw an arc in the height direction. The pitching adjusting shaft 33 is a shaft for swinging the glass G in the thickness direction about this axis. The rolling adjustment shaft 34 is a shaft for swinging the glass G in the thickness direction around this axis (swing in a direction perpendicular to the pitching swing axis). The X-axis error absorbing mechanism 35 is a shaft that balances both ends of a shaft that can move to the left and right with a spring, and is a shaft that enables fine adjustment of the position of the glass G in the X-axis direction. The pivot axis 36 is an axis that allows the glass to rotate ± 90 degrees around this axis.
[0030]
These axes allow the operator to fit the glass G into the vehicle body 10 while keeping the glass G in the desired posture.
[0031]
Note that these shaft configurations and the arm 24 are connected via an alignment portion 37. The alignment unit 37 is a part that functions as an alignment unit constituting the second follow-up unit of the present invention.
[0032]
FIG. 3 shows a detailed configuration of the alignment unit 37. 3A is a diagram showing the alignment unit 37 viewed from the same direction as FIG. 2, and FIG. 3B is a diagram showing the alignment unit 37 viewed from the side of FIG. is there.
[0033]
The alignment unit 37 includes a servo motor 40, an LM guide 41, a ball screw 42, and a moving table 43. The moving table 43 is supported so as to be movable along the LM guide (in the drawing (A), the front and back direction of the paper surface). The moving table 43 is provided with a nut portion 44 that engages with the ball screw 42, and the moving table 43 reciprocates as the ball screw 42 rotates. The moving table 43 is connected to the shaft configuration shown in FIG. The operation of the alignment unit 37 is controlled by a controller (described later) provided exclusively as a position control means (described later).
[0034]
Therefore, if the movement table 43 is reciprocated by controlling the operation of the servo motor 40 so that the relative speed between the tracking device 23 and the vehicle body 10 is zero and the relative position is constant, the vehicle body The glass can be attached while following 10 accurately. Since the weight of the alignment unit 37 is lighter than that of the follower 23, it is relatively easy to quickly respond to the constantly changing relative speed and relative position.
[0035]
Next, the control of the tracking device 23 and the tracking control of the alignment unit 37 will be described with reference to the block diagrams and flowcharts of FIG.
[0036]
As shown in FIG. 4, the distance measuring sensor A is input to the controller 50 that functions as movement control means or position control means via the sensor controller, and the speed sensor B is also input to the controller 50. In this embodiment, two sensors, ranging sensor A and speed sensor B, are used. As described above, one of the sensors is sufficient.
[0037]
The rotary encoder 52 is for calculating the follow-up speed of the follow-up device 23, and the signal from the encoder 52 is also input to the controller 50. The encoder 52 functions as a follow-up speed detection unit. The encoder 52 is not particularly required when the speed sensor B is used.
[0038]
The conveyor speed of the chain conveyor is detected by the encoder 54, and the detected signal is input to the controller 50.
[0039]
The synchronization timing sensor 56 is a sensor for synchronizing the tracking of the vehicle body 10 conveyed by the chain conveyor with the tracking device 23. When a signal is output from the sensor 56, the tracking of the tracking device 23 is started. The
[0040]
The inverter 57 controlled by an instruction from the controller 50 controls the rotational speed of the AC motor 58 of the tracking device 23. The controller 50 also controls the operation of the servo motor 40 of the glass attachment unit 25.
[0041]
The basic loop circuit and the correction circuit are configured by the above components, and the tracking operation of the tracking device 23 that tracks a specific part of the vehicle body 10 based on the reference is controlled by this circuit.
[0042]
FIG. 5 is a block diagram showing only the control system of the tracking operation of the tracking device 23 as the first tracking means and the glass mounting portion 25 as the second tracking means in the block diagram shown in FIG.
[0043]
As shown in FIG. 5A, a reference input signal is created from the conveyor speed detected by the encoder 54, and the speed creation circuit 60 creates a target value based on the reference input signal. The motor 58 of the follow-up device 23 rotates based on this target value, and pulses output from the encoder 52 along with this rotation are counted by the counter 62. The follow-up of the follow-up device 23 is controlled by a closed loop including a D / A converter, an inverter 57, a motor 58, an encoder 52, and a counter 62.
[0044]
As shown in FIG. 5B, a reference input signal is created from the signal detected by the distance sensor A or the speed sensor B, and the speed creation circuit 60 creates a target value based on the reference input signal. The motor 40 of the glass attachment part 25 as the second follower rotates based on this target value, and the glass attachment part 25 follows the vehicle body 10 accurately.
[0045]
The flowchart in FIG. 6A is a flowchart showing the tracking operation of the tracking device 23. Note that the conveyor speed of the chain conveyor is substantially constant as shown by the solid line a in FIG.
[0046]
When the synchronization timing sensor 56 in FIG. 4 detects the vehicle body 10 conveyed to the chain conveyor, the tracking operation of the tracking device 23 is started (S1). When the follow-up operation is started, the conveyor speed detected by the encoder 54 is input to the speed creating circuit 60, and the motor 58 increases the speed until this speed is reached (S2). Then, when it catches up with the speed of the chain conveyor, it follows at a constant speed (S3).
[0047]
A state of the speed fluctuation of the follower 23 is shown by a dotted line B in FIG. That is, the speed is gradually increased from the time when the vehicle body 10 is detected by the synchronization timing sensor 56, and a slight hunting, which exceeds or falls below the speed of the chain conveyor, is repeated to follow at a constant speed.
[0048]
The flowchart of FIG. 6B is a flowchart illustrating the tracking operation of the moving table 43 of the glass attachment unit 25.
[0049]
When the synchronization timing sensor 56 in FIG. 4 detects the vehicle body 10 conveyed to the chain conveyor, the tracking operation of the glass attachment portion 25 is started (S11). When the follow-up operation is started, the detection signal of the distance sensor A or the speed sensor B is input to the speed creation circuit 60, and the motor 40 increases the speed until it catches up with this speed. That is, the moving table 43 is moved so that the relative speed between the glass attachment portion 25 and the vehicle body 10 becomes zero, and compensation is made for the speed that the follower 23 cannot keep up with. Since the weight of the glass attachment portion 25 is very light compared to the weight of the follower 23, the rising speed can be increased, and such compensation is relatively easy (S12). Thereafter, very accurate follow-up control is performed so that the relative speed between the follow-up device 23 and the vehicle body 10 is zero (S13).
[0050]
The state of the speed fluctuation of the glass mounting portion 25 is shown by a one-dot chain line C in FIG. That is, the speed is rapidly increased to compensate for the relative speed from the time when the vehicle body 10 is detected by the synchronization timing sensor 56, so that the vehicle speed can quickly catch up with the conveyance speed of the vehicle body 10. Since the speed of the follow-up device 23 increases after a while, the speed of the glass attachment portion 25 is decreased with this increase. Thereafter, when the follower 23 reaches a steady speed, the speed of the glass attaching device 25 is changed so as to cancel the periodic speed change of the chain conveyor (S13).
[0051]
As described above, according to the workpiece follower of the present invention, the follow-up to the vehicle body 10 is performed with extremely high accuracy in the two parts of the follower 23 having a relatively heavy weight and the glass attachment portion 25 having a light weight.
[0052]
In the present embodiment, the case where the present invention is applied to the glass mounting device is illustrated, but the present invention is not limited to this, and the tracking device is divided into a heavy portion and a light portion, and the heavy portion is the average speed of the tracking target object. As long as it is suitable for use in compensating for fluctuations so that the relative speed between the object to be followed and this heavy part is zero at a light part, any other production machine can be used. Applicable.
[0053]
Next, a second embodiment of the workpiece follower according to the present invention will be described. In this embodiment, the glass mounting part 25 is configured to move up and down by an elevating cylinder, and the follow-up control is also slightly different from that in the first embodiment.
[0054]
FIG. 8 is a view of the workpiece follower according to the present embodiment as viewed from the conveyance direction of the vehicle.
The rail 21 is provided along the conveyance path of the vehicle body 10. The rail 21 is movably attached to a rail 22 installed so as to be orthogonal to the conveyance path, and a tracking device 23 that follows the vehicle body 10 is movably attached to the rail 21. The follow-up device 23 includes a traveling unit 70 that travels on the rail 21, a slide unit 72 to which the glass attachment unit 25 is attached, and an elevating cylinder 74 that raises and lowers the slide unit 72.
[0055]
FIG. 9 is a diagram illustrating a specific configuration of the traveling unit 70. The traveling unit 70 is attached to the rail 21 via a cam follower 71 so as to straddle the two rails 21, and a rack 76 for moving the traveling unit 70 is attached to one rail 21. The traveling unit 70 is aligned so that the center position thereof coincides with the center position of the vehicle body 10. A motor 80 that rotates a pinion 78 that meshes with the rack 76 is attached to the traveling unit 70. The rotation of the motor 80 is controlled by a controller 82 and an inverter 84 for tracking control.
[0056]
Therefore, when the motor 80 rotates, the traveling unit 70 moves in the conveyance direction of the vehicle body 10, and can follow the vehicle body 10 by controlling the rotation speed. This rotational speed is controlled by the controller 82 in accordance with the conveyance speed of the vehicle body 10.
[0057]
FIGS. 10A and 10B are diagrams illustrating a specific configuration of the slide portion 72. This slide part 72 is attached to the raising / lowering cylinder 74 attached to the traveling part 70, and corresponds to the alignment part 37 shown in the first embodiment.
[0058]
The slide portion 72 includes a base 90 attached to the elevating cylinder 74 and a table 100 to which the glass attachment portion 25 is attached. The table 100 is supported by a linear motor 92 and a support by a servo motor 91 attached to the base 90. Driven through unit 95.
[0059]
The table 100 is supported so as to be movable along the linear motion guide 92 (in the direction of the paper surface in the figure (B)). The table 100 is provided with a nut portion 94 that engages with the ball screw 93, and the table 100 reciprocates by the rotation of the ball screw 93 connected to the servo motor 91 via the coupling 96. The table 100 is attached with a hand or the like that directly works, but in this embodiment, the shaft configuration shown in FIG. 2 exemplified in the first embodiment is connected. The operation of the slide portion 72 is controlled by a controller 102 and a servo unit 104 which are provided exclusively as position control means.
[0060]
By configuring the following device 23 as described above, the operations of the motor 80 and the servo motor 91 are performed so that the relative speed between the following device 23 and the vehicle body 10 becomes zero and the relative position becomes constant. If it is controlled, the glass can be attached while accurately following the vehicle body 10. Since the weight of the slide portion 72 is considerably lighter than the weight of the entire follower 23, it is relatively easy to quickly respond to the constantly changing relative speed and relative position.
[0061]
FIG. 11 is an overall view of the workpiece follower according to the present embodiment, and is a view for explaining an attachment state of a sensor used for follow-up in particular. 12A and 12B are diagrams showing specific mounting positions of the sensor, and FIG. 13 is a diagram for explaining the function of the sensor. FIG. 14 is a block diagram showing a configuration of a sensor control system.
[0062]
The sensor 110 is attached to a sensor arm 120 attached to the tracking device 23. As shown in FIG. 12, the sensor 110 includes a displacement sensor 112 (also referred to as a synchronization sensor) for detecting the relative position between the vehicle body 10 and the apparatus, and a reflective photoelectric sensor for detecting the intrusion of the vehicle body 10. 114 (also referred to as a synchronization timing sensor).
[0063]
As shown in FIG. 13A, the reflective photoelectric sensor 114 detects the window frame portion of the vehicle body 10 from the change in the reflected light, thereby detecting the intrusion of the vehicle body 10. The detection signal from the reflective photoelectric sensor 114 is input to the input unit of the controller 116 shown in FIG.
[0064]
The displacement sensor 112 is a sensor that starts measuring the relative position from when the detection signal of the reflective photoelectric sensor 114 is input to the sensor detection controller 116. The relative position information output from the displacement sensor 112 is as follows. Amplified by the amplifier 118 and input to the high-speed counter of the controller 116. The controller 116 can input relative position information from the displacement sensor 112 at intervals of 10 msec, and can detect the relative position in mm.
[0065]
As described above, the schematic mechanical configuration of the workpiece follower according to the present embodiment is as described above. Next, the overall configuration and operation of the control system will be described in detail.
FIG. 15 is a block diagram of a control system according to the present embodiment.
[0066]
An axis controller 130 in the figure functions as a movement control means or a position control means, and includes a controller 82 for follow-up control shown in FIG. 9, a controller 102 that functions as a position control means shown in FIG. 116 functions as three controllers.
[0067]
A detection signal from the reflective photoelectric sensor 114 is directly input to the axis controller 130. The axis controller 130 starts follow-up control by the input of this detection signal.
The relative position information output from the displacement sensor 112 is amplified by the amplifier 118 and input to the axis controller 130 as a pulse output.
[0068]
The motor 80 that drives the traveling unit 70 is connected to the axis controller 130 via the inverter 84, and the axis controller 130 moves the traveling unit 70 in synchronization with the vehicle body 10 based on the relative position information from the displacement sensor 112. .
[0069]
The servo motor 91 that drives the slide unit 72 is connected to the axis controller 130 via the servo unit 104, and the axis controller 130 synchronizes the slide unit 72 with the vehicle body 10 based on the relative position information from the displacement sensor 112. Move.
[0070]
Next, the operation of the work following apparatus in the present embodiment will be described based on the flowcharts of FIGS. 16 to 18.
The flowcharts shown in FIGS. 16 and 17 show the control of the traveling unit 70.
[0071]
First, the chain conveyor is driven and the vehicle body 10 is conveyed (S21). When the reflection type photoelectric sensor 114 detects the windshield window frame portion of the vehicle body 10 as shown in FIG. Based on the relative position information output from the sensor 112, the conveyance speed of the vehicle body 10 is calculated. The specific steps for calculating the transport speed are shown in the flowchart of FIG. This flowchart will be described later (S22).
[0072]
The axis controller 130 calculates the speed command value of the motor 80 that drives the traveling unit 70 from the calculated conveyance speed of the vehicle body 10 (S23), and sets the relative position detected by the displacement sensor 112 (FIG. 13B). As shown, if the position Xmm behind the window frame is the reference position for synchronization, and the difference between the reference position and the current position value is -20 mm or more, the inverter starting speed is set to double, while the relative If the position is -2 mm or more, the inverter speed is set to V.
[0073]
That is, at the start of follow-up when the traveling unit 70 is positioned before the reference position, the rotational speed of the motor 80 is changed depending on how far the distance is. When it is positioned 20 mm or more in front, the traveling unit 70 is started slowly, and at 2 mm or more in front, it is moved at the set inverter speed V (S24 to S27).
[0074]
Next, after the tracking is started, when the traveling unit 70 is located 2 mm or more behind the reference position, that is, when following the delay, the speed is obtained by adding α to the inverter speed V. If the motor 80 is rotated to catch up with the reference position (S28, S29), and the traveling unit 70 is located 2 mm or more ahead of the reference position, that is, if it is following the previous run, the inverter The motor 80 is rotated at a speed obtained by subtracting α from the speed V so as to approach the reference position. This control is repeated during the follow-up period (S30, S31).
[0075]
If the traveling unit 70 has advanced 20 mm or more ahead of the reference position during tracking, the inverter speed is set to 0 and the traveling unit 70 is stopped (S32, S33). As described above, the traveling unit 70 normally follows in the range of ± 2 mm of the reference position.
[0076]
FIG. 17 is a subroutine flowchart of processing for calculating the conveyance speed of the vehicle body 10 shown in step 22 of FIG.
When the chain conveyor is driven to start the conveyance of the vehicle body 10 and when the window portion of the windshield of the vehicle body 10 is detected by the reflective photoelectric sensor 114 as shown in FIG. 13 (S41), it is provided in the axis controller 130. The value of the high-speed counter for the displacement sensor 112 is reset to 0 (S42). When the vehicle body 10 continues to be conveyed and reaches the reference position (S43), the two measurement timers built in the axis controller 130 are reset (S44). When the measurement timer 1 measures 100 msec, the axis controller 130 stores (stores 1) the position (current value) from the reference position (S45, S46). When the measurement timer 2 measures 200 msec, the axis controller 130 moves to the reference position. The position (current value) from is stored (memory 2) (S47, S48).
[0077]
The axis controller 130 obtains a displacement amount of 100 msec from the two stored current values (S49), and obtains the transport speed of the vehicle body 10 from this displacement amount (S50).
[0078]
FIG. 18 is a flowchart showing the operation of the slide unit 72.
[0079]
When the measurement timer built in the axis controller 130 finishes counting for 10 msec, the relative position detected by the displacement sensor 112 is detected (S51). If the traveling unit 70 is located within 2 mm forward of the reference position as a result of this detection, the difference between the reference position and the current position is set as the movement amount of the slide unit 72 (S52, S53). When the part 70 is located within 2 mm behind the reference position, the difference between the reference position and the current position is set as the operation amount of the slide part 72 (S54, S55). The above control is repeated when the relative position detected by the displacement sensor 112 is within 20 mm, and ends when it exceeds 20 mm (S56).
[0080]
As a result, the servo motor 91 moves the slide part 72 by the amount of deviation from the reference position, and absorbs the tracking error by the traveling part 70.
[0081]
As described above, the relatively heavy running unit 70 is controlled based on the relative position detected every 100 msec, and the relatively light slide unit 72 is based on the relative position detected every 10 msec. Will be controlled.
[0082]
Therefore, according to the work following apparatus in the present embodiment, it is possible to accurately follow based on the deviation from the reference position set in advance in the vehicle body.
[Brief description of the drawings]
FIG. 1 is a schematic configuration diagram of a glass mounting apparatus to which a workpiece follower of the present invention is applied.
FIG. 2 is a configuration diagram of a glass attachment portion of the glass attachment device in the workpiece follower according to the present invention.
FIG. 3 is a diagram showing a detailed configuration of an alignment unit in the workpiece follower according to the present invention.
FIG. 4 is a block diagram of a control system of the workpiece follower according to the present invention.
FIG. 5 is a block diagram of a control system of the first tracking means or the second tracking means of the workpiece tracking device according to the present invention.
FIG. 6 is a diagram for explaining an operation of a control system of the workpiece follower according to the present invention.
FIG. 7 is a flowchart showing the control of the workpiece follower according to the present invention.
FIG. 8 is a diagram of a workpiece follower according to a second embodiment as viewed from the conveyance direction of a vehicle.
FIG. 9 is a diagram showing a specific configuration of a traveling unit shown in FIG.
10A and 10B are diagrams showing a specific configuration of the slide portion shown in FIG.
FIG. 11 is an overall view of the workpiece follower according to the present embodiment.
12A and 12B are diagrams showing specific mounting positions of the sensor, in which FIG. 12A is a top view of the sensor and FIG. 12B is a front view of the sensor.
FIG. 13 is a diagram for explaining the function of a sensor.
FIG. 14 is a block diagram showing a configuration of a sensor control system.
FIG. 15 is a block diagram of a control system of the work following apparatus according to the present embodiment.
FIG. 16 is a flowchart showing control of the workpiece follower according to the present embodiment.
FIG. 17 is a flowchart showing control of the workpiece follower according to the present embodiment.
FIG. 18 is a flowchart showing control of the workpiece follower according to the present embodiment.
[Explanation of symbols]
10 ... the car body,
20 ... Glass mounting device,
23 ... following device,
25 ... Glass mounting part,
37 ... alignment part,
40 ... motor,
43 ... moving table,
50 ... Controller,
70 ... traveling part,
72 ... slide part,
74 ... Elevating cylinder,
110 ... sensor,
112 ... displacement sensor,
114 ... reflective photoelectric sensor,
130: Axis controller.

Claims (4)

A workpiece transfer means for transferring a workpiece;
Workpiece conveyance speed detection means for detecting the conveyance speed of the workpiece conveyed by the workpiece conveyance means;
First follow-up means for following the workpiece at an average conveyance speed based on the conveyance speed detected by the workpiece conveyance speed detection means;
Follow-up speed detecting means for detecting the follow-up speed when the first follow-up means is following the workpiece;
A relative speed calculating means for calculating a relative speed from the conveying speed detected by the workpiece conveying speed detecting means and the following speed detected by the following speed detecting means;
A second follower attached to the first follower for following the workpiece so as to have the same transport speed as that of the workpiece according to the relative speed calculated by the relative speed calculator ;
A workpiece follower characterized by comprising: The first follow-up means includes
Parallel running means installed so as to be able to run together with the workpiece conveyed by the workpiece conveying means;
A movement control means for controlling the movement of the parallel means according to the conveyance speed detected by the workpiece conveyance speed detection means;
Work follow-up device according to claim 1, wherein the composed. The second following means is
Alignment means attached to the first follower means so as to follow the workpiece within a certain range;
2. The workpiece follow-up according to claim 1 , further comprising position control means for controlling the position of the alignment means so that the relative speed that changes every moment calculated by the relative speed calculation means becomes zero. apparatus. 4. The work following apparatus according to claim 3 , wherein the weight of the alignment means included in the second following means is lighter than the weight of the parallel means included in the first following means .

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