JP2001038657A - Device and method for holding article to be carried - Google Patents

Abstract

PROBLEM TO BE SOLVED: To reduce the frequency of the alarm output and the operation stop as much as possible by repeatedly trying the holding operation when a holding mistake occurs, and to improve operation efficiency, to reduce the recovery work of workers, and to improve the quality of products. SOLUTION: This holding device advances a hand 4 provided in an advancing/retracting manner, and holds a hand receiving handle 6 of an article to be carried. This holding device comprises holding error detecting means 15, 16, 30 to detect a holding error of the handle 6 by the hand 4, and a control part 30 to retract the hand 4 when the holding error is detected by the holding error detecting means 15, 16, 30, change the advancement of the hand 4, and advance the hand again to hold the handle 6.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a device and a method for gripping a conveyed object, wherein the conveyed object is gripped by a hand mounted on the conveyed vehicle when the object is transferred to the conveyed vehicle. In particular, the present invention relates to a device and a method for gripping a transported object, which can be retried when an error occurs in gripping the transported object (failure in gripping).

[0002]

2. Description of the Related Art FIG. 4 is a schematic perspective view mechanically showing the entire configuration of a conventionally known apparatus for gripping a conveyed object, and FIG. 5 is a schematic block diagram showing the configuration of the same gripping apparatus. In these drawings, reference numeral 1 denotes a rail provided in a plant or the like, for example, 2 is provided on a rail 1, and a transport vehicle 3 running along the rail 1 is mounted on a transport vehicle 2; Pusher 4 is provided so as to be able to move forward and backward in a direction perpendicular to the traveling direction of the pusher 4, a hand provided at the tip of the pusher 3, 5 is placed at a predetermined location near the rail 1, and is conveyed by the carrier 2. A transfer object 6 such as a tank (tank) is provided at a predetermined position of the transfer object 5 and is a hand receiver as a gripping portion of the transfer object that is gripped by the hand 4 moved forward by the pusher 3.

As shown in FIG. 5, the pusher 3 is provided so as to be able to move forward and backward in the directions of arrows A and B by a pusher driving device 11 constituted by, for example, a rack / pinion mechanism. The pusher 3 is provided at an appropriate position in the vicinity of the hand 4, which is formed of a magnetic material and is provided in the vicinity of the hand 4, which is formed of a magnetic material and detected by a magnetic sensor described later, and uses the magnetic force to open or grip the hand. A hand driving device 14 and a hand state detection sensor 15 for detecting that the hand 4 is open or gripped are provided. The hand state detection sensor 15 is configured by a magnetic sensor that detects that the hand 4 is in the proximity state when the hand 4 is open, for example, by configuring the hand 4 with a magnetic material.

The hand 4 is attached to the tip of the pusher 3 so as to be swingable in the direction of arrow CD and urged by a spring (not shown) in the direction of arrow C (the direction of the hand receiver 6 for the conveyed object). When the hand drive device 14 is energized, the hand drive device 14 swings in the direction of arrow D to be in an open state.
Swinging in the direction, and is engaged with the hand receiver 6 so that the hand receiver 6 is gripped.

[0005] A handle detection sensor 16 for detecting the hand receiver 6 is provided at an appropriate position of the hand 4. As the handle detection sensor 16, for example, a magnetic sensor can be used by configuring the hand receiver 6 with a magnetic material.

On the other hand, a forward position sensor 13 which is fixed to a predetermined position of the transport vehicle 2 and is constituted by a magnetic sensor is provided at an appropriate position of the transport vehicle 2, and the forward position sensor 13 and the forward position sensor 13 are provided. The metal fitting 12 constitutes a position detecting unit for detecting that the pusher 3 and thus the hand 4 are at a predetermined forward position. The forward position sensor bracket 12 has a predetermined length, and the leading end portion 12a and the rear end portion 12b can be identified and detected by the forward position sensor 13.

Further, a control device 30 for controlling the pusher driving device 11 to control the forward and backward movement of the pusher 3 is provided on the transporting trolley 2, and the control device 30 includes a forward position sensor 13, a hand driving device 14, State detection sensor 1
5. The handle detection sensor 16 is connected.

[0008] The operation of the above-described conventional gripping device will be described below. When the carriage 2 stops at a predetermined position, the control device 30 operates the pusher driving device 11 to move the pusher 3 forward. Then, the forward position sensor 13
When the leading end portion 12a of the forward position sensor fitting 12 is detected, a preset time T1s from the time point P0 is detected.
After ec, the pusher 3 is stopped, and the hand 4 is driven by the hand driving device 14 into a gripping state to grip the hand receiver 6. In this case, the control device 30 determines that the hand state is the grip state based on the output signal 15a of the hand state detection sensor 15, but the output signal 16a of the handle detection sensor 16
When the hand receiver 6 is not detected on the basis of the above, it is determined that a grip error by the hand 4 has occurred and an alarm is output,
Stop operation. Note that the time T1 is a time previously determined as a time at which the hand 4 can hold the hand receiver 6, and is stored in the control device 30.

[0009]

However, in the case where the above-described gripping error occurs, there is an error in the attachment position of the hand receiver of each conveyed object, and there is a variation in the position where the conveyed object is placed. There is a case where the aging of the factory building causes a change in the distance between the location of the conveyed goods and the rail of the conveyer, and an error in the stop position of the conveyer. In some cases, the gripping error can be prevented by slightly changing the forward position of the gripper and performing the gripping operation again. Therefore, in all such cases, an alarm is output,
Stopping the operation of transporting the conveyed material lowers the operation efficiency, and requiring a return operation by a human increases labor and labor costs of the human. Further, there is a problem that the stop time until the return to the operation is prolonged, which is a factor of deteriorating the product quality.

SUMMARY OF THE INVENTION The present invention has been made to solve the above-mentioned conventional problems. When a gripping error occurs, the gripping operation is attempted again to reduce the alarm output and the operation stop frequency as much as possible. , Thereby improving operating efficiency,
It is an object of the present invention to provide a gripping device and a gripping method for a conveyed object that can reduce the returning work of a person and improve the product quality.

[0011]

In order to solve the above-mentioned problems, a conveyed object gripping apparatus according to the present invention moves a hand (4) provided to be able to move forward and backward to grip a conveyed object (5). In the gripping device for a transported object (5) configured to grip the portion (6), a grip error detecting means (15,
16, 30) and the gripping error detecting means (15, 16,
If a grip error is detected by (30), the hand (4) is moved backward, the advance amount of the hand (4) is changed and the hand (4) is advanced again, and the grip portion (6) of the transported object (5) is moved. ) And a control unit (30) for controlling the gripping.

[0012] According to such a configuration, when the forward stop position of the hand (4) is different from the position of the grip portion (6) of the conveyed object, which causes a grip error, the forward movement is performed. By changing the position and retrying, it is possible to automatically eliminate a gripping error.

In the embodiment, the transported object 5 is
Although the present invention is applied to a tank (tank) provided in a pipeless plant, the present invention can be widely applied to various works used in various plants and factories, containers for raw materials, and the like.
In the embodiment, the grip error detection means of the present invention includes a hand state detection sensor 15 for detecting the open state and the grip state of the hand 4, and a handle detection sensor 16 for magnetically detecting the hand receiver 5. , Hand state detection sensor 1
5 detection signal 15a and handle detection sensor 16 detection signal 1
6a, the controller 30 determines whether or not a grip error has occurred. However, it goes without saying that the present invention is limited to these configurations. Further, in the embodiment, the change of the set time of the timer, the position of the position sensor, and the like are used as the means for changing the advance amount. However, the drive amount for moving the hand forward may be detected.

Further, according to the present invention, there is provided the apparatus for gripping a conveyed object according to claim 1, further comprising a position detector (12, 13) for detecting a predetermined forward position (P0) of the hand (4), The control unit (30) controls the advance amount of the hand (4) based on the predetermined advance position (P0) detected by the position detection unit.

According to such a configuration, the position can be detected easily and accurately. In the embodiment, the position detection unit is fixed in position with respect to the carrier 2 and has a forward position sensor 13 provided corresponding to a predetermined forward position of the hand 4 (that is, the pusher 3); The forward position sensor 13 is constituted by a magnetic sensor. The forward position sensor 13 is constituted by a magnetic sensor. However, another position sensor such as an optical sensor or a potentiometer is used. It may be configured by using this.

According to a second aspect of the present invention, in the apparatus for gripping a conveyed object according to the second aspect, the control unit (30) controls a timer when the position detection unit (12, 13) detects a predetermined forward position (P0). Is set, and when the timer expires, the forward movement of the hand (4) is stopped, and
The advance amount of the hand (4) is changed by changing the set time of the timer.

According to such a configuration, the position can be freely set by changing the set time of the timer with reference to one predetermined forward position P0, and a structure for detecting the forward position is provided. For example, there is no need to provide a large number of position sensors or sensor fittings, and cost reduction can be achieved.

According to a third aspect of the present invention, in the apparatus for gripping a conveyed object according to the third aspect, the hand (4) and the grasping portion (6) of the conveyed object (5) are used when the hand (4) is moved backward. The control unit (30) has a structure in which the gripping unit (6) is gripped by being engaged with the gripping unit (6). When the gripping error is detected, the control unit (30) sets the timer setting time to an initial setting time. After setting (T3) larger than (T1) to advance the hand (4), the hand (4) is controlled to retreat.

According to such a configuration, when a grip error is detected, the possibility of eliminating the grip error in the second try is extremely high, and the operating efficiency can be improved.

Further, according to the present invention, there is provided an apparatus for gripping a conveyed object in which a hand provided so as to be able to move forward and backward is used to hold a predetermined forward position (P0) of the hand (4). Position detecting unit (12, 1) for detecting
3) a control unit (30) for controlling the advance / retreat of the hand (4) based on a detection signal of the position detection unit (12, 13) to grip the grip unit (6); (4) a gripping error detecting means (15, 16) for detecting a gripping error of the gripping portion (6), wherein the hand (4) and the gripping portion (6) of the conveyed object (5) are When the hand (4) is retracted, the gripper (6) is engaged with the gripper (6) so that the gripper (6) is gripped. Position (P0),
A second forward position which is a position further advanced than the first forward position (P0) and which is a position further advanced than a position where the grip portion (6) of the article (5) is assumed to be located; When the position (P2) is detected, the control unit (30) controls the hand (4) to advance to the second advance position (P2) and then to retract when the grip error is detected. It is a feature.

According to such a configuration, when a grip error is detected, there is no need to retreat the hand 4, the grip error can be quickly eliminated, and the operating efficiency can be further improved. In the embodiment, the first forward position P0 is a position where the distal end portion 12a of the forward position fitting 12 is detected by the forward position sensor 13, and the second forward position P2 is the position of the forward position fitting 12. The rear end portion 12b is a position detected by the forward position sensor 13.

According to the present invention, in the apparatus for gripping a conveyed object according to any one of claims 1 to 5, the hand (4) is provided with a conveyer (2) for conveying the conveyed object (5). ).

According to such a configuration, it is not necessary to dispose the hand 4 at, for example, various stations, so that the cost can be reduced and the degree of freedom in design can be increased.

Further, the method for gripping a conveyed object according to the present invention comprises
In the gripping method of the transported object (5), wherein the gripping portion (6) of the transported object (5) is gripped by controlling the advance amount of the hand (4), the gripping portion (6) of the hand (4) is used. When a grip error is detected, the advance amount of the hand (4) is changed according to a predetermined algorithm, and the gripping operation of the transported object (5) by the hand (4) is repeated. Is what you do.

According to such a configuration, when the forward stop position of the hand (4) is different from the position of the grip portion (6) of the conveyed object, which causes a grip error, the forward movement is performed. By changing the position and retrying, it is possible to automatically eliminate a gripping error.

In the first embodiment, the predetermined algorithm refers to a case in which the set time of the timer is changed so that the forward movement amount is increased and then reduced, and in the second embodiment, When a grip error occurs, the hand is immediately advanced to the predetermined position P2, and the hand 4 is retracted to grip the hand receiver 6. In the third embodiment, the set time of the timer is changed to a longer time to advance. A case where the amount is increased and the hand receiver 6 is gripped while the hand 4 is retracted.

[0027]

Embodiments of the present invention will be described below with reference to the drawings. The present invention, when a grip error is detected, changes the forward position of the hand according to a predetermined algorithm and performs the grip operation again, and the overall configuration of the grip device and the device The diagrams showing the functional blocks are the same as those shown in FIGS. 4 and 5, and a description thereof will be omitted.

Embodiment 1 In the first embodiment, if an initial (first) gripping error occurs, the next (second) retry is performed by greatly changing the advance amount of the hand 4, and the second try is also performed. If a grip error has occurred, the advance amount of the hand 4 is changed next (third time) to be smaller than the first advance amount, and a retry is performed. A grip error also occurs in the third try. In this case, the advance amount of the hand 4 is returned to the first advance amount and a retry is performed. If a grip error still occurs, an alarm is issued.

Hereinafter, the above operation will be described more specifically with reference to the flowchart of FIG. In FIG. 1, when the gripping operation starts, the pusher 3 is advanced in step S1. In this forward operation, the pusher 3 is advanced at a high speed from the position P0 at which the distal end portion 12a of the forward position sensor fitting 12 is detected until a time T1 (0.2 sec) set by the timer elapses. This is done by:

When the pusher 3 is stopped after the elapse of the set time T1 of the timer, in step S2, the hand driving device 14 is operated and the hand receiver 6 is operated.
Is gripped. Then, in step S3, it is determined whether or not the hand receiver 6 of the tank (tank), which is the transported object 5, is being gripped (whether or not a grip error has occurred). This determination is made based on the output signals 15a and 16a of the hand state detection sensor 15 and the handle detection sensor 16, and when the hand is in the gripping state and the hand grip is detected, the gripping is performed normally. On the other hand, when the handle is not detected even though the hand is in the gripping state, it is determined that the gripping error is handled in the present invention.

If it is determined in step S3 that a grip error has occurred, the process proceeds to step S4, where the hand 4 is opened by the hand driving device 14, and the pusher 3 is retracted. This retreating operation is performed at a high speed until the hand 4 is located at the center of the carrier 2. In the position control of the retreating operation, for example, a retreat position sensor and a retreat position sensor fitting (not shown) which work as a pair similarly to the forward position sensor 13 and the forward position sensor fitting 12 shown in FIG. By providing the pusher 3 and the pusher 3 at appropriate positions, a detection unit for detecting the retreat position is configured.
The detection signal of the detection section can be used.

In step S5, when the hand 4, that is, the pusher 3 retreats to the original position, then, in step S6, the set time of the timer is changed from T1 to T2 (0.
4 seconds) (T2> T1), and pusher 3 is advanced. This forward movement is substantially the same as step S1 than the position P0 at which the distal end portion 12a of the forward position sensor fitting 12 is detected.
This is performed by advancing the pusher 3 at high speed until 2 (0.4 sec) elapses. Therefore, the pusher 3 is advanced to the front by 0.2 sec at a higher speed than the first advance amount.

In step S7, the gripping operation of the hand receiver 6 is performed in the same manner as in step S2.
In step 8, it is determined whether or not a grip error has occurred, similarly to step S3. If it is determined that a grip error has occurred, the process proceeds to step S9, where the hand 4 is released, and in step S10, The pusher 3 is retracted at a high speed to the center of the carriage. Then, as a third try, next, in step 11, the pusher 3 is advanced by setting the timer set time from T2 to T0 (0.0 sec). In this case, the pusher 3 is moved forward until the distal end portion 12a of the forward position sensor fitting 12 is detected by the forward position sensor 13. Then, at this position, hand grip is performed in step S12, and then determination of a grip error is performed in step S13.

If a grip error is determined in the third try, the hand 4 is released again (step S1).
4) Then, retreat at high speed to the center of the carrier 2 (step S15). As a fourth try, step S16
In, the timer is set to the first value (initial value T1), the pusher 3 is advanced, and the hand is gripped in step S17. This is the last set timer value, that is, the timer set value obtained experimentally at the time of design or equipment (a value (advance amount) assumed as the advance amount that the hand can hold the handle). In the case where the first gripping error is accidentally generated by performing the trial, the alarm is performed in order to prevent the occurrence of an alarm or the like due to the gripping error.

In step S18, a grip error is determined. If a grip error is also determined in this case, a grip error alarm is issued in step S19 for the first time, and the operation is stopped in step S20. You.

On the other hand, if it is determined in step S3, step S8, step S13, and step S18 that no grip error has occurred, the process proceeds to step S21, where the conveyed object (tank) on the station side is opened, and step S22 is performed. Then, the pusher 3 is moved backward to transfer the conveyed object to the conveyer trolley, and the gripping operation ends.

According to the first embodiment, when a grip error occurs, the grip operation is repeatedly performed before and after the position (initial setting value) where the hand receiver is assumed to be located, The possibility that the grip error can be eliminated can be increased.

Embodiment 2 Next, a second embodiment of the present invention will be described with reference to FIG. In the second embodiment, when the structure of the hand 4 and the hand receiver 6 for the conveyed object shown in FIG. 5 is such that the hand 4 is de-energized, that is, the pusher 3 is retracted while the hand 4 is held. If there is a hand receiver 6 in this retreating direction, the hand 4
Has a structure to be engaged with the handle 6,
When a grip error is detected, the hand 4 is moved forward (for example, at the pusher advancing end) from a position where the hand receiver 6 is assumed to be present, and then the hand 4 is retracted while maintaining the grip state. It is like that. For such a hand receiver 6, the hand structure adopts, for example, a structure in which the hand 4 is held in a non-energized state when no power is applied, and is in an energized state when the power is applied and the hand 4 is opened. Can be.

The operation of the second embodiment will be described below with reference to FIG. First, when the gripping operation starts, the pusher 3 is advanced in step S31. This forward operation is the same as that described in step S1, and the time T1 set in the timer is further increased from the position P0 at which the distal end portion 12a of the forward position sensor fitting 12 is detected.
Until the elapse of (0.2 sec), the pusher 3 is moved forward at a high speed.

When the pusher 3 is stopped after the elapse of the set time T1 of the timer, in step S32, the hand driving device 14 is operated to operate the hand receiver 6.
Is gripped. Then, in step S33, it is determined whether or not the hand receiver 6 of the tank (tank), which is the transported object 5, is being gripped (whether or not a grip error has occurred).

If it is determined that the gripping error has occurred, the hand 4 is opened by turning on the hand driving device 14 in step S34, and the pusher 3 is moved to the rear end of the forward-position sensor bracket 12 in step S35. The unit 12b is advanced at a low speed to the position P2 where the hand 12 is detected. Then, in step S36, the hand 4 is de-energized by the hand driving device 14 to hold the hand 4, and in steps S37 to S39, the handle 6 is gripped. Until the detection is performed, the pusher 3 is retreated at a low speed to the position P0. Then, if it is determined in step S39 that the position P0 has been reached without performing the grip detection in step S38, the process proceeds to step S40, and after issuing a grip error alarm, the operation is stopped in step S41 and the process is terminated. finish.

On the other hand, steps S33 and S3
In step S8, if it is determined that no grip error has occurred, the process proceeds to step S42, where the conveyed object (tank) on the station side is opened, and the pusher 3 is pressed in step S43.
Is retracted, the conveyed object is transferred to the conveyer trolley, and the gripping operation ends.

According to the second embodiment, when a grip error is detected, the hand 4 is moved forward from a position where the hand receiver 6 is assumed to be present, and then the hand 4 is brought into the grip state. By maintaining and retreating, the hand receiver 6 can be grasped, and as in the first embodiment,
The hand is retracted to the trolley every time a grip error is detected, and the operation of changing the timer setting time is not required. The grip error can be eliminated quickly, operation efficiency can be improved, and the operation setting can be easily performed. It has the advantage that it becomes.

Embodiment 3 FIG. In the second embodiment, when the pusher 3 is advanced due to the determination of the grip error, the pusher 3 is advanced until the position information P2 of the sensor is detected. When it is determined, the pusher 3 is moved backward once, and then the set time of the timer is changed to be longer to move the pusher 3 forward.

The operation of the third embodiment will be described below with reference to FIG. First, when the gripping operation starts, the pusher 3 is advanced in step S51. This forward operation is the same as that described in step S1, and the time T1 set in the timer is further increased from the position P0 at which the distal end portion 12a of the forward position sensor fitting 12 is detected.
Until the elapse of (0.2 sec), the pusher 3 is moved forward at a high speed.

Then, when the pusher 3 is stopped after the elapse of the set time T1 of the timer, the hand driving device 14 is operated to move the hand receiver 6 in step S52.
Is gripped. In step S53, a determination is made as to whether or not the hand receiver 6 of the tank (tank), which is the transported object 5, is being gripped (whether or not a grip error has occurred).

If it is determined that there is a grip error, the hand 4 is opened by turning on the hand driving device 14 in step S54, and the pusher 3 is retracted at a high speed to the center of the carrier in step S55.
Thereafter, in step S56, the pusher 3 is advanced by setting the time set by the timer to T3. This set time T
In the third embodiment, a time is selected such that the pusher 3 moves forward to a position corresponding to the position P2 in the second embodiment.

After the forward movement of the pusher 3 is completed, in step S57, the hand driving device 14 is de-energized to put the hand 4 in the gripping state. In steps S58 to S60, the gripping of the handle 6 is detected. Until the operation is performed, the pusher 3 is moved backward to the position P0 at a low speed. If it is determined that the position P0 has been reached in step S60 without performing the grip detection in step S59, the process proceeds to step S61, and after issuing a grip error alarm, the operation is stopped in step S62 and the process is terminated. finish.

On the other hand, steps S53 and S5
In step S9, if it is determined that no grip error has occurred, the process proceeds to step S63, where the conveyed object (tank) on the station side is opened, and in step S64, the pusher 3 is pressed.
Is retracted, the conveyed object is transferred to the conveyer trolley, and the gripping operation ends.

According to the third embodiment, once a predetermined position is detected by the position sensor, the pusher 3 can be advanced to the predetermined forward position by changing the time setting of the timer. As compared with the second embodiment, there is an advantage that it is not necessary to detect two positions by the position sensor.

[0051]

As described in detail above, according to the present invention, when a gripping error occurs, the gripping operation is attempted again,
Provided is a conveyed object gripping device and a conveyed object gripping method that can reduce alarm output and operation stop frequency as much as possible, thereby improving operation efficiency, reducing human return work, and improving product quality. It has the effect that it can be done.

[Brief description of the drawings]

FIG. 1 is a flowchart showing a first embodiment.

FIG. 2 is a flowchart showing a second embodiment.

FIG. 3 is a flowchart showing a third embodiment.

FIG. 4 is an overall configuration diagram illustrating a device for gripping a conveyed object.

FIG. 5 is a schematic block diagram illustrating a configuration of a signal system of a transported object gripping device.

[Explanation of symbols]

 Reference Signs List 2 transport cart 3 pusher 4 hand 5 transported object 6 hand receiver 11 pusher drive device 12 forward position sensor bracket 13 forward position sensor 14 hand drive device 15 hand state detection sensor

Claims (7)

[Claims] 1. A device for gripping a conveyed object (5) in which a hand (4) provided to be able to move forward and backward is moved forward to grip a gripper (6) of the conveyed object (5). 4) a gripping error detecting means (15, 16, 30) for detecting a gripping error of the gripping portion (6), and a gripping error detected by the gripping error detecting means (15, 16, 30). A control unit (30) that controls the hand (4) to retreat, change the amount of advance of the hand (4), advance the hand again, and grip the gripper (6) of the transported object (5). ) Is provided. 2. The apparatus according to claim 1, further comprising: a position detector (12, 13) for detecting a predetermined forward position (P0) of the hand (4); 30) An apparatus for gripping a conveyed object, wherein an amount of advance of the hand (4) is controlled based on the predetermined advance position (P0) detected by the position detector. 3. The apparatus for gripping a conveyed object according to claim 2, wherein said control unit (30) comprises said position detection unit (12, 13).
A timer is set when a predetermined forward position (P0) is detected by the following, and when the timer expires, the forward movement of the hand (4) is stopped, and the set time of the timer is changed, whereby the hand is changed. (4) An apparatus for gripping a conveyed object, wherein the amount of advance is changed. 4. A device for gripping a conveyed object according to claim 3, wherein said hand (4) and a gripper (6) for said conveyed object (5).
Has a structure in which the hand (4) is engaged with the grip portion (6) when the hand (4) is retracted, and the grip portion (6) is gripped. The control portion (30) detects the grip error. A gripping device for a conveyed object characterized in that the setting time of the timer is set to be longer (T3) than the initial setting time (T1) and the hand (4) is controlled to move forward and then backward. . 5. A conveyed object gripping device in which a conveyed object gripping portion is gripped by a hand provided so as to be capable of moving forward and backward, wherein a predetermined advance position (P0) of the hand (4) is detected. A position detection unit (12, 13);
A control unit (30) for controlling the advance and retreat of the hand (4) based on the detection signals of (2, 13) to grip the gripping unit (6), and the gripping unit (6) by the hand (4); )
Gripping error detecting means (15, 16) for detecting gripping errors
And a gripper (6) for the hand (4) and the transported object (5).
Has a structure in which the hand (4) is engaged with the gripping part (6) when the hand (4) is retracted, and the gripping part (6) is gripped. 1 (P0) and a position further advanced than the first advanced position (P0), and further than a position where the gripper (6) of the transported object (5) is assumed to be located. The controller (30) detects a second forward position (P2), which is a forward position, and detects the hand (4) when the grip error is detected.
The control device is controlled so as to advance after moving to the second advance position (P2) and then to retract. 6. The apparatus according to claim 1, wherein the hand (4) is mounted on a transport trolley (2) for transporting the transported object (5). An apparatus for gripping a conveyed object. 7. A method for gripping a conveyed object (5), wherein the amount of advance of the hand (4) is controlled to grip the gripped portion (6) of the conveyed object (5). When the gripping error of the gripper (6) is detected, the advance amount of the hand (4) is changed according to a predetermined algorithm, and the gripping operation of the transported object (5) by the hand (4) is repeated. A method for gripping a conveyed object, characterized in that: