Conveying System

Abstract

To provide a technique that is effective in making a conveying system, which enables a cooperative robot to convey an object to be conveyed in cooperation with a worker, low-cost and excellent in work efficiency.SOLUTION: A conveying system 1, which enables a cooperative robot 20 to deliver an object 10 to be conveyed in cooperation with a worker C, is provided with; a robot arm 21 provided in the cooperative robot 20 so that the arm holds the object 10 to be conveyed in tandem with the worker C holding the object 10 to be conveyed; a detecting device 30 that detects external-load information IF concerning an external load F inputted to the robot arm 21; and a control device 40 that controls the cooperative robot 20. When the external load F is inputted to the robot arm 21 from the worker C through the object 10 to be conveyed, the control device 40 performs worker follow-up control by which motion of the robot arm 21 is made to follow up motion of the object 10 to be conveyed by the worker C on the basis of the external load information IF detected by the detecting device 30.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to a conveyance system. [Background technology]

[0002] Patent Document 1 below discloses an automatic assembly device for automatically assembling vehicle parts. This automatic assembly device is configured to grip, transport, and attach vehicle parts to a vehicle body using a gripping hand attached to a robot, and to fasten the vehicle parts to the vehicle body using a fastener tightening device attached to another robot. This automatic assembly device can automate the sophisticated assembly work of vehicle parts that was previously performed by workers using robots. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Publication No. 59-53275 Summary of the Invention [Problem to be solved by the invention]

[0004] When using the above-mentioned automatic assembly system, the robot must be large to handle heavy vehicle parts. Furthermore, if it is assumed that the vehicle parts will be assembled by robots from both sides of the vehicle body, multiple robots must be used. Therefore, in either case, the cost of the system can become high.

[0005] To address this issue, it is effective to use a robot known as a "collaborative robot" that can assist workers in their work. Collaborative robots can reduce the load on the robot by working with workers to carry out tasks such as transporting and assembling items like vehicle parts. This allows for the use of small robots to transport vehicle parts, thereby keeping equipment costs low.

[0006] However, the use of collaborative robots can cause the following problems. Specifically, if the robot arm transports vehicle parts at a slow speed, workers must move slowly or intermittently to match this transport speed, resulting in reduced work efficiency. On the other hand, if the robot arm transports vehicle parts at an excessively fast speed, workers find it difficult to keep up with the robot arm's movements. In this case, the transport work cannot be performed continuously, resulting in reduced work efficiency, similar to when the transport speed is slow. This type of reduced work efficiency problem can occur not only when transporting vehicle parts before they are assembled into the vehicle body, but also when simply transporting various transported items such as vehicle parts.

[0007] The present invention has been made in consideration of such problems, and aims to provide an effective technology for making a transportation system in which a worker and a collaborative robot work together to transport objects inexpensive and highly efficient. [Means for solving the problem]

[0008] One aspect of the present invention is A transportation system that transports an object in collaboration between a worker and a collaborative robot, a robot arm provided on the collaborative robot to hold the transported object in parallel with the worker holding the transported object; a detection device for detecting external load information relating to an external load input to the robot arm; a control device for controlling the collaborative robot; an imaging device for imaging the worker; Equipped with The control device includes: When the external load information detected by the detection device exceeds a threshold, it is recognized that the worker is performing the action of transporting the transported object based on the image information acquired by the photographing device. The external load is input from the worker to the robot arm via the transported object. It is determined that and a worker tracking control is performed to make the movement of the robot arm follow the worker's movement of carrying the transported object based on the external load information detected by the detection device. 、 The control device is configured to perform an abnormality notification control for notifying a system abnormality without performing the worker tracking control when it is recognized that the worker is not performing the operation of carrying the transported object based on the image information from the photographing device in a case where the external load information detected by the detection device exceeds a threshold value. conveying systems, is located. [Effects of the Invention]

[0009] In the transportation system of the above-described aspect, the robot arm of the collaborative robot is used to hold the transported object in parallel with the worker holding the transported object. That is, the worker and the collaborative robot collaborate so that the worker and the robot arm separately access the transported object and hold it. This allows the weight load of the transported object to be shared between the worker and the collaborative robot, which has the advantage of allowing the use of small, inexpensive robots without increasing the number of robots compared to a structure in which the transported object is transported by robots alone. However, because the operator and the robot arm can operate separately, there is a possibility that a difference will occur between the movement of the operator and the movement of the robot arm. In this case, the worker will have to move in accordance with the movement of the robot arm, which may result in a decrease in work efficiency.

[0010] Therefore, the transportation system of this aspect is configured to perform worker following control, which causes the collaborative robot to follow the worker. This worker following control is a control that causes the movement of the robot arm to follow the worker's movement to transport the transported object, based on external load information detected by the detection device, when an external load is input to the robot arm from the worker via the transported object. With this worker following control, by causing the robot arm to follow the movement of the worker, the transportation task can be performed in collaboration with the collaborative robot in accordance with the worker's movement, thereby improving the work efficiency of the transportation task of the transported object.

[0011] As described above, according to the above-mentioned aspects, it is possible to provide an effective technology for making a transportation system in which a worker and a collaborative robot work together to transport objects inexpensive and with excellent work efficiency. [Brief explanation of the drawings]

[0012] [Figure 1] 1 is a perspective view showing the overall configuration of a transport system according to a first embodiment. [Figure 2] FIG. 2 is a block diagram of a first arithmetic processing unit of the control device in FIG. 1. [Figure 3]FIG. 2 is a block diagram of a second arithmetic processing unit of the control device in FIG. 1. [Figure 4] 2 is a flowchart of a transport process control by the transport system of FIG. 1; [Figure 5] 5 is a flowchart of the worker following control in FIG. 4. [Figure 6] 5 is a flowchart of the abnormality notification control in FIG. 4. DETAILED DESCRIPTION OF THE INVENTION

[0013] Preferred embodiments of the above aspects are described below.

[0014] In the transport system of the above aspect, it is preferable that the robot arm has a shaft portion that constitutes an arm joint and a drive motor built into the shaft portion, and the detection device has a current measurement portion that measures a motor current of the drive motor, and is configured to detect, as the external load information, a fluctuation value of the motor current measured by the current measurement portion when the external load is input.

[0015] According to this transport system, external load information relating to an external load input to the robot arm can be detected as a fluctuation value of the motor current using the current measurement unit of the detection device, thereby simplifying the detection structure for external load information by using the current measurement unit.

[0016] In the transportation system of the above aspect, it is preferable that the control device, in the worker following control, derives the worker transporting speed of the transported item by the worker from the fluctuation value of the motor current measured by the current measuring unit of the detection device, and feedback controls the drive motor of the robot arm so that the robot transporting speed of the transported item by the collaborative robot approaches this worker transporting speed.

[0017] According to this transportation system, by feedback controlling the drive motor of the robot arm so that the speed at which the collaborative robot transports the robot approaches the speed at which the worker transports the object, worker tracking control can be performed, which causes the movement of the robot arm to follow the worker's movement to transport the object.

[0018] The transportation system of the above-mentioned aspect preferably includes a photographing device that photographs the worker, and when the control device recognizes that the worker is performing the transporting operation of the transported item based on image information acquired by the photographing device, it determines that the external load has been input from the worker to the robot arm via the transported item, and accurately performs the worker tracking control.

[0019] This transportation system uses a camera to capture an image of the worker to recognize whether the worker is currently transporting an object, and then determines based on the recognition result whether an external load has been input to the robot arm from the worker via the object. In this case, the accuracy of determining the cause of the external load input to the robot arm can be improved, and unnecessary worker tracking control can be prevented from being performed.

[0020] In the transportation system of the above-mentioned aspect, when the control device recognizes based on image information from the photographing device that the worker is not currently performing the transportation operation of the transported item, it is preferable that the control device performs abnormality notification control to alert the user to a system abnormality without performing the worker tracking control.

[0021] According to this transport system, if the cause of the external load input to the robot arm is not caused by the worker, the worker can be quickly notified by the abnormality notification control that the cause is a system abnormality.

[0022] In the transport system of the above aspect, the collaborative robot is preferably configured so that the weight that can be carried by the robot arm is less than the weight of the object being transported.

[0023] According to this transport system, the collaborative robot itself can be made smaller by configuring the collaborative robot so that the weight that can be carried by the robot arm is less than the weight of the object being transported.

[0024] Hereinafter, a specific structure of the transport system according to one embodiment of the above aspect will be described with reference to the drawings.

[0025] (Embodiment 1) 1, the transportation system 1 of the first embodiment is for transporting an object 10 in collaboration between a worker C and a collaborative robot 20. The transportation system 1 is mainly composed of the collaborative robot 20, a detection device 30, a control device 40, and an imaging device 70. Other elements may be added to these components as appropriate.

[0026] 1. Configuration of Collaborative Robot 20 The collaborative robot (hereinafter simply referred to as "robot") 20 is an articulated robot. The robot 20 has a robot arm 21. The robot arm 21 is provided on the robot 20 so as to hold the transported object 10 in parallel with the worker C who is holding the transported object 10. In other words, the robot arm 21 is configured to directly hold the transported object 10 with the holding portion 21a at the tip of the arm, and the holding portion 21a is a different part of the transported object 10 from the part where the worker C directly holds the transported object 10 by grasping it from both sides with his fingers Ca.

[0027] Therefore, "collaboration" in this embodiment refers to a mode in which the worker C and the robot arm 21 independently access and hold the transported object 10 during transportation. In this case, the worker C directly holds the transported object 10, while the robot arm 21 simultaneously directly holds the transported object 10. In contrast, for example, a mode in which the worker C grabs and holds the robot arm 21 while it is holding the transported object 10, in which the robot arm 21 directly holds the transported object 10 but the worker C does not directly hold the transported object 10, is essentially different from the "collaboration" defined here.

[0028] The transported item 10 is transported, for example, from point A designated by the symbol "10(A)" to point B designated by the symbol "10(B)" through cooperation between the worker C and the robot 20. At this time, point B may simply be a destination to which the transported item 10 is transferred, or, if the transported item 10 is a vehicle part, it may be a destination to which the vehicle part is to be assembled to a vehicle body.

[0029] The robot 20 is preferably configured so that the weight capacity of the robot arm 21 is less than the weight of the transported object 10. In this case, the load of the weight of the transported object 10 is shared between the worker C and the robot 20. This has the advantage that the robot 20 itself can be made smaller than a structure in which the weight capacity of the robot arm 21 exceeds the weight of the transported object 10.

[0030] The size and shape of the transported object 10 are not particularly limited as long as the transporting work can be shared between the worker C and the robot 20. Various items, including vehicle parts, can be used as the transported object 10. The worker C can grasp and hold the transported object 10, or support and hold the transported object 10 from below.

[0031] The robot arm 21 has a plurality of shafts 22 that constitute the arm joints, and a drive motor 23 built into each shaft 22. Each drive motor 23 functions to drive the robot arm 21 so as to control the position and orientation of the holding part 21a to a desired state.

[0032] The number of shafts 22 and drive motors 23 in the robot arm 21 is not particularly limited and can be changed as needed. The structure of the holding unit 21a of the robot arm 21 is also not particularly limited. The structure of the holding unit 21a can be, for example, a structure that grips and holds the transported object 10, a structure that supports and holds the transported object 10 from below, or a structure that suction-holds the transported object 10.

[0033] 2. Configuration of the detection device 30 The detection device 30 has the function of detecting external load information IF relating to the external load F input from the holder 21 a of the robot arm 21. To achieve this function, the detection device 30 is electrically connected to the drive motor 23 and has a current measurement unit 31 as a current sensor that measures the motor current of the drive motor 23.

[0034] This detection device 30 can detect, as external load information IF, the fluctuation value of the motor current measured by the current measurement unit 31 when an external load F is input to the robot arm 21. In other words, when an external load F is input to the robot arm 21, the motor current in the drive motor 23 increases to maintain the posture of the robot arm 21 against the external load F. Therefore, it can be determined that the increase in motor current at this time is due to the external load F. Therefore, the fluctuation value of the motor current is taken as external load information IF that indirectly indicates the external load F.

[0035] The external load information IF detected by the detection device 30 is transmitted to the control device 40 electrically connected to the detection device 30. In this case, the external load F refers to the input load input by the worker C holding the transported item 10. Therefore, the load equivalent to the weight of the transported item 10 is excluded from the external load F.

[0036] The detection device 30 only needs to have at least the function of detecting the external load information IF, and may include, instead of or in addition to the current measurement unit 31, a voltage sensor that detects fluctuations in the motor voltage of the drive motor 23, a torque sensor (mechanical sensor) that detects fluctuations in the torque acting on the drive motor 23, etc. The detection device 30 may be built into the robot 20 or the control device 40, or may be configured as a device separate from the robot 20 or the control device 40.

[0037] 3. Configuration of the control device 40 The control device 40 is a control panel having a function of controlling the robot 20. In particular, the control device 40 controls the movement of the robot arm 21 so that the transported object 10 is transported while being held by the holding portion 21a of the robot arm 21. The control device 40 is also provided with an alarm 41 for notifying of an abnormality in the robot 20.

[0038] 4. Configuration of the imaging device 70 The photographing device 70 is composed of a camera that has the function of photographing the worker C and the surrounding area. With this photographing device 70, an image is captured by an imaging element by receiving light reflected from the subject. A CCD (Charge Coupled Device) image sensor or a CMOS (Complementary Metal Oxide Semiconductor) image sensor is typically used as the imaging element. With this photographing device 70, it is possible to obtain image information IG, which is three-dimensional image data showing the state of the worker C and the surrounding area. The image information IG obtained by the photographing device 70 is then transmitted to the control device 40, which is electrically connected to the photographing device 70.

[0039] 5. Structure of the arithmetic processing unit of the control device 40 The control device 40 has a first arithmetic processing unit 50 (see FIG. 2) and a second arithmetic processing unit 60 (see FIG. 3). The control device 40 is equipped with a known CPU (Central Processing Unit), ROM, RAM, an interface for inputting and outputting data to and from external devices, and the like, in order to execute arithmetic processing in each arithmetic processing unit.

[0040] As shown in Figure 2, the first calculation processing unit 50 of the control device 40 includes external load information acquisition units 51, 52, a data input unit 53, a robot transport speed acquisition unit 54, a data memory unit 55, a model generation unit 56, a model memory unit 57, a worker transport speed derivation unit 58, and a transport speed evaluation unit 59.

[0041] The external load information acquisition unit 51 acquires external load information IF from the detection device 30 and inputs this external load information IF to the data storage unit 55. In contrast, the external load information acquisition unit 52 acquires external load information IF from the detection device 30 and inputs this external load information IF to the worker transport speed derivation unit 58.

[0042] The data input unit 53 inputs various data required to generate the transporting speed estimation model Ma to the data storage unit 55. The transporting speed estimation model Ma is a model that defines the relationship between the external load information IF and the transporting speed of the transported item 10 by the worker C (the "worker transporting speed Va" described below). This transporting speed estimation model Ma is a set model including set parameters (also referred to as a "trained model including trained parameters"). Therefore, the "various data" referred to here includes an operation dataset, an operation program (pre-operation parameters), and the like that are prepared in advance for machine learning (commonly referred to as "AI learning") of the transporting speed of the transported item 10 by the worker C.

[0043] The robot transport speed acquisition unit 54 acquires the robot transport speed Vb from the robot 20. This robot transport speed Vb is the speed at which the robot 20 transports the transported object 10, and in this embodiment, corresponds to the movement speed of the holding unit 21a of the robot arm 21. For example, a detection means such as a rotary encoder (not shown) that is built into the drive motor 23 so as to be able to detect the amount of mechanical displacement of rotation can be used, and the robot transport speed Vb can be calculated based on data detected by this detection means.

[0044] The model generation unit 56 generates the transportation speed estimation model Ma through machine learning using the working data set read out from the data storage unit 55. Then, the model generation unit 56 outputs the generated transportation speed estimation model Ma to the model storage unit 57. Note that instead of generating the transportation speed estimation model Ma through machine learning, the model generation unit 56 may generate the transportation speed estimation model Ma in accordance with a correlation model, a regression model, mapping data, or the like that is stored in advance in the data storage unit 55.

[0045] The worker carrying speed derivation unit 58 inputs the external load information IF acquired by the external load information acquisition unit 52 into the carrying speed estimation model Ma read from the model storage unit 57. As a result, the worker carrying speed derivation unit 58 derives the worker carrying speed Va, which is the speed at which the worker C carries the transported object 10. In this embodiment, this worker carrying speed Va corresponds to the moving speed of the fingers Ca of the worker C, which move substantially integrally with the transported object 10.

[0046] The carrying speed evaluation unit 59 compares the worker carrying speed Va derived by the worker carrying speed derivation unit 58 with the robot carrying speed Vb acquired by the robot carrying speed acquisition unit 54, corrects the robot carrying speed Vb as necessary, and then outputs a control signal Sa to the robot 20 for controlling the drive motor 23 of the robot arm 21. Therefore, for the robot 20 controlled at the corrected robot carrying speed Vb, the robot carrying speed Vb is acquired again by the robot carrying speed acquisition unit 54.

[0047] As shown in FIG. 3, the second calculation processing unit 60 of the control device 40 includes image information acquisition units 61, 62, a data input unit 63, a data storage unit 64, a model generation unit 65, a model storage unit 66, and a worker condition evaluation unit 67.

[0048] The image information acquisition unit 61 acquires image information IG from the photographing device 70 and inputs this image information IG to the data storage unit 64. In contrast, the image information acquisition unit 62 acquires image information IG from the photographing device 70 and inputs this image information IG to the worker condition evaluation unit 67.

[0049] The data input unit 63 inputs various data required to generate the worker state estimation model Mb into the data storage unit 64. The worker state estimation model Mb is a model that defines the relationship between the image information IG and the state of the carrying work of the worker C. This worker state estimation model Mb is a set model including set parameters (also referred to as a "trained model including trained parameters"). Therefore, the "various data" here includes a work dataset, a work program (pre-work parameters), etc. that are prepared in advance for machine learning of the state of the carrying work of the worker C.

[0050] The model generation unit 65 generates the worker state estimation model Mb by machine learning using the work data set read from the data storage unit 64. Then, the model generation unit 65 outputs the generated worker state estimation model Mb to the model storage unit 66. Note that instead of generating the worker state estimation model Mb by machine learning, the model generation unit 65 may generate the worker state estimation model Mb in accordance with a correlation model, a regression model, mapping data, etc. stored in advance in the data storage unit 64.

[0051] The worker state evaluation unit 67 inputs the image information IG acquired by the image information acquisition unit 62 into the worker state estimation model Mb read from the model storage unit 66. As a result, the worker state evaluation unit 67 derives the state of the transport work of the worker C (information such as the presence or absence of the worker C, the movement direction of the worker C, and the movement trajectory of the worker C), and based on this, determines whether the worker C is actually performing the work of transporting the transported item 10.

[0052] 6. Transport process control by transport system 1 Next, with particular reference to FIGS. 4 to 6, the transport process control by the transport system 1 configured as described above will be described.

[0053] The transport process control according to the first embodiment is achieved by sequentially executing steps S101 to S108 in Fig. 4. If necessary, other steps may be added, any step may be divided into multiple steps or deleted, or the order of the steps may be changed.

[0054] Step S101 is a step in which worker C activates the photographing device 70 to start photographing with the photographing device 70. According to step S101, by constantly acquiring image information IG from the photographing device 70, it becomes possible to constantly recognize the status of the transport work of worker C.

[0055] Step S102 is a step in which the worker C starts controlling the robot 20 by activating the robot 20. According to step S101, the robot 20 is ready to transport the transported object 10 in collaboration with the worker C.

[0056] Step S103 is a step in which the current measurement unit 31 of the detection device 30 measures the motor current of the drive motor 23 and determines whether the fluctuation value of the measured motor current exceeds a preset threshold value. In step S103, the fluctuation value of the motor current actually measured in the drive motor 23 is evaluated. In step S103, if the fluctuation value of the motor current exceeds the threshold value, exceed The process proceeds to step S104 on the condition that it is determined that the above condition is met. This step S103 is executed by the first arithmetic processing unit 50 of the control device 40, for example.

[0057] Step S104 is a step for determining whether or not the worker C is currently performing a transporting operation. In this step S104, the determination result by the worker state evaluation unit 67 (see FIG. 3) of the control device 40 is used. This step S104 makes it possible to identify whether or not the worker C is actually performing a transporting operation of the transported item 10. If it is determined in step S104 that the worker C is currently performing a transporting operation (in the case of "Yes" in FIG. 4), the process proceeds to step S105; otherwise (in the case of "No" in FIG. 4), the process proceeds to step S106.

[0058] In this embodiment, when it is recognized in step S104 based on the image information IG from the imaging device 70 that the worker C is performing a carrying operation, it is determined that the external load F (see FIG. 1) has been input from the worker C to the robot arm 21 via the transported object 10, and the "worker following control" is executed in step S105. The worker following control is generally a control that causes the movement of the robot arm 21 to follow the movement of the worker C to carry the transported object 10 based on the external load information IF detected by the detection device 30.

[0059] On the other hand, when it is recognized in step S104 based on the image information IG from the imaging device 70 that the worker C is not performing the transport work, it is determined that an abnormality has occurred in the transport system 1, and the "abnormality notification control" in step S106 is executed without executing the "worker following control" in step S105. Note that if the answer is "No" in step S104, it is also possible to skip step S106 and directly end the transport process control.

[0060] Step S107 is a step in which the operator C ends the robot control by stopping the robot 20. In addition, step S108 is a step in which the operator C ends the photographing by the photographing device 70 by stopping the photographing device 70.

[0061] As shown in FIG. 5, the "operator following control" corresponding to step S105 in FIG. 4 includes steps S105a to S105e.

[0062] Step S105a is a step for deriving worker carrying speed Va. In step S105a, worker carrying speed derivation unit 58 (see FIG. 2) of control device 40 is used. According to step S105a, by inputting external load information IF (in this embodiment, the fluctuation value of the motor current of drive motor 23) into carrying speed estimation model Ma, it is possible to derive worker carrying speed Va, which corresponds to the moving speed of fingers Ca of worker C.

[0063] Step S105b is a step for acquiring the robot transport speed Vb. This step S105b uses the robot transport speed acquisition unit 54 (see FIG. 2) of the control device 40. According to this step S105b, by detecting the amount of mechanical displacement of rotation of the drive motor 23 using a detection means such as a rotary encoder, it is possible to derive the robot transport speed Vb, which corresponds to the movement speed of the holding part 21a of the robot arm 21.

[0064] Step S105c is a step of comparing the worker carrying speed Va derived in step S105a with the robot carrying speed Vb derived in step S105b. This step S105c uses the carrying speed evaluation unit 59 (see FIG. 2) of the control device 40. According to this step S105c, the speed difference between the worker carrying speed Va and the robot carrying speed Vb is calculated.

[0065] Step S105d is a step for determining whether or not correction of the robot carrying speed Vb is necessary. In this step S105d, the carrying speed evaluation unit 59 of the control device 40 is used, as in step S105c. According to step S105d, if the speed difference between the worker carrying speed Va and the robot carrying speed Vb is large enough to exceed a threshold, it is determined that correction of the robot carrying speed Vb is necessary, and the process proceeds to step S105e. On the other hand, if the speed difference between the worker carrying speed Va and the robot carrying speed Vb is small enough to be below the threshold, it is determined that correction of the robot carrying speed Vb is not necessary, and the process of step S105 is terminated.

[0066] Step S105e is a step of correcting the robot carrying speed Vb. In this step S105e, the carrying speed evaluation unit 59 of the control device 40 is used, as in steps S105c and S105d. According to step S105e, the robot carrying speed Vb is corrected so as to approach the worker carrying speed Va. Then, a control signal Sa for realizing the corrected robot carrying speed Vb is output to the robot 20, and the drive motor 23 of the robot arm 21 is controlled based on this control signal Sa.

[0067] After step S105e is executed, the process returns to step S105b, and the series of processes (feedback control) from step S105b to step S105e are executed sequentially, whereby the drive motor 23 of the robot arm 21 is feedback-controlled so that the robot carrying speed Vb approaches the worker carrying speed Va.

[0068] This type of feedback control makes it possible to make the robot carrying speed Vb match the worker carrying speed Va or to make the robot carrying speed Vb approximate the worker carrying speed Va. Therefore, the movement of the robot arm 21 can be made to follow the movement of the worker C to carry the object 10 so that the carrying speed Vb on the robot 20 side approaches the carrying speed Va on the worker C side. As a result, it is possible to make the robot 20 perform collaborative work that matches the working pace of the worker C.

[0069] As shown in FIG. 6, the "abnormality notification control" corresponding to step S106 in FIG. 4 includes steps S106a and S106b.

[0070] Step S106a is a step of forcibly terminating robot control in accordance with the determination result of the occurrence of an abnormality in the transport system 1. Furthermore, step S106b outputs a control signal to the alarm 41 to notify the abnormality in accordance with the determination result of the occurrence of an abnormality in the transport system 1. As a result, the alarm 41 outputs an abnormality notification state to notify the occurrence of the abnormality using an output mode such as audio output, screen output, or print output.

[0071] According to the above-described first embodiment, the following effects can be obtained.

[0072] In the transportation system 1 of the first embodiment, the robot arm 21 of the robot 20 is used to hold the transported object 10 in parallel with the worker C who holds the transported object 10. That is, the worker C and the collaborative robot 20 cooperate to separately access the transported object 10 and hold it. This allows the weight load of the transported object 10 to be shared between the worker C and the robot 20, and has the advantage of allowing the use of small, inexpensive robots 20 without increasing the number of robots 20, compared to a structure in which the transported object is transported solely by the robot 20. On the other hand, because the operator C and the robot arm 21 can operate separately, there is a possibility that a difference will occur between the movement of the operator C and the movement of the robot arm 21. In this case, the worker C will move in accordance with the movement of the robot arm 21, which may result in a decrease in work efficiency.

[0073] Therefore, the transportation system 1 of this embodiment is configured to perform worker following control, which causes the robot 20 to follow the worker C. This worker following control is a control that causes the movement of the robot arm 21 to follow the transporting action of the transported object 10 by the worker C, based on external load information IF detected by the detection device 30, when an external load F is input from the worker C to the robot arm 21 via the transported object 10. According to this worker following control, by making the robot arm 21 follow the movement of the worker C, the transporting work that matches the movement of the worker C can be performed in cooperation with the robot 20, thereby improving the work efficiency of the transporting work of the transported object 10.

[0074] Therefore, according to the first embodiment, the transport system 1 in which the worker C and the robot 20 cooperate to transport the transported object 10 can be made inexpensive and have excellent work efficiency.

[0075] According to the transport system 1 of the first embodiment, the external load information IF regarding the external load F input to the robot arm 21 can be detected as a fluctuation value of the motor current using the current measurement unit 31 of the detection device 30. Therefore, the detection structure of the external load information IF can be simplified by the current measurement unit 31.

[0076] According to the transportation system 1 of embodiment 1, by feedback controlling the drive motor 23 of the robot arm 21 so that the robot transport speed Vb by the robot 20 approaches the worker transport speed Va by the worker C, worker tracking control can be accurately performed to make the movement of the robot arm 21 follow the transport movement of the transported item 10 by the worker C.

[0077] According to the transportation system 1 of the first embodiment, it is possible to recognize whether the worker C is currently transporting the transported object 10 by using the imaging device 70 that captures an image of the worker C, and then determine based on the recognition result whether the external load F has been input from the worker C to the robot arm 21 via the transported object 10. In this case, it is possible to improve the accuracy of determining the cause of the external load F input to the robot arm 21, and to prevent unnecessary execution of worker following control.

[0078] According to the conveying system 1 of embodiment 1, if the cause of the external load F input to the robot arm 21 is not due to the worker C, the worker C can be quickly notified by the abnormality notification control that this cause is due to a system abnormality.

[0079] According to the transport system 1 of the first embodiment, the robot 20 is configured so that the weight that can be carried by the robot arm 21 is less than the weight of the transported object 10, and therefore the robot 20 itself can be made smaller.

[0080] Although the present disclosure has been described with reference to the above-described embodiments, it is understood that the present disclosure is not limited to these embodiments or structures. The present disclosure also encompasses various modifications and equivalent variations. In addition, various combinations and embodiments, including only one element, more than one element, or less than one element, are also within the scope and spirit of the present disclosure.

[0081] In the above embodiment, the case where the transporting speed Vb of the robot 20 is made to approach the transporting speed Va of the worker C in the worker following control has been exemplified, but as long as the movement of the robot arm 21 can be made to follow the transporting action of the transported object 10 by the worker C, a transporting parameter other than the transporting speed of the robot 20 may be made to approach the transporting parameter other than the transporting speed of the worker C. As the transporting parameter other than the transporting speed, for example, a transporting trajectory, a transporting direction, etc. can be adopted.

[0082] In the above embodiment, the external load information IF is the fluctuation value of the motor voltage of the drive motor 23, and the worker transport speed Va is derived from this fluctuation value of the motor voltage. However, instead of or in addition to this, the fluctuation value of the motor voltage of the drive motor 23 or the fluctuation value of the torque acting on the drive motor 23 may be used as the external load information IF, and the worker transport speed Va may be derived from this external load information IF.

[0083] In the above embodiment, an example is given of a case where a photographing device 70 that photographs worker C is used to recognize whether worker C is currently performing the action of transporting the transported item 10, but the photographing device 70 can be omitted, for example, if an alternative means to the photographing device 70 can be used or if there is no need to recognize whether worker C is currently performing the action of transporting the transported item 10.

[0084] In the above embodiment, an example is given of a case where the weight capacity of the robot arm 21 of the robot 20 is less than the weight of the transported object 10, but if necessary, a structure may be adopted in which the weight capacity of the robot arm 21 is equal to or greater than the weight of the transported object 10. [Explanation of symbols]

[0085] 1. Conveying system 10 Transported goods 20 Robots (Collaborative Robots) 22 Shaft 23 Drive motor 21 Robotic Arm 30 Detection device 31 Current measurement section 40 Control device 70 Imaging equipment C. Worker F External load IF External Load Information IG Image Information Va Worker transport speed Vb Robot transport speed

Claims

1. A transportation system that transports an object in collaboration between a worker and a collaborative robot, a robot arm provided on the collaborative robot to hold the transported object in parallel with the worker holding the transported object; a detection device for detecting external load information relating to an external load input to the robot arm; a control device for controlling the collaborative robot; an imaging device for imaging the worker; Equipped with the control device is configured to, when it is recognized that the worker is performing the action of carrying the transported object based on the image information acquired by the photographing device in a case where the external load information detected by the detection device exceeds a threshold, determine that the external load is input from the worker to the robot arm via the transported object, and perform worker tracking control to cause the movement of the robot arm to follow the action of carrying the transported object by the worker based on the external load information detected by the detection device; The control device is configured to perform abnormality notification control to notify of a system abnormality without performing the worker tracking control when the external load information detected by the detection device exceeds a threshold value and it is recognized based on image information from the photographing device that the worker is not currently performing the transport operation of the transported item.

2. the robot arm has a shaft portion that constitutes an arm joint and a drive motor built into the shaft portion, 2. The transport system according to claim 1, wherein the detection device has a current measurement unit that measures a motor current of the drive motor, and is configured to detect a fluctuation value of the motor current measured by the current measurement unit when the external load is input as the external load information.

3. 3. The transportation system of claim 2, wherein the control device, in the worker following control, derives a worker transporting speed of the transported object by the worker from a fluctuation value of the motor current measured by the current measuring unit of the detection device, and feedback controls the drive motor of the robot arm so that the robot transporting speed of the transported object by the collaborative robot approaches this worker transporting speed.

4. The transport system according to any one of claims 1 to 3, wherein the collaborative robot is configured so that the weight that can be carried by the robot arm is less than the weight of the object being transported.

Images