JP2020015160A - Personal protection device of robot - Google Patents

Abstract

To provide a personal protection device utilizing an electric field system of a cooperative robot, which is configured to make a distance at which approach of the robot to a worker can be detected longer with a simple structure without using an electrode on a floor.SOLUTION: A personal protection device of a robot 1 with a simple structure which is constituted of: an AC voltage adding device 3 to be held by a worker 2 who works around the robot 1; an electrode 4 provided in the robot 1; and a measuring instrument 5 with a ground electrode 7 which measures a voltage value of the electrode 4, in which when the robot approaches the worker 2 and the voltage of the electrode 4 rises, a control signal corresponding to the voltage value measured by the measuring instrument 5 is sent to a controller 6 of the robot 1 to make the robot 1 perform operation for personal protection on the basis of the control signal received by the controller 6. With this structure, the AC voltage adding device 3 applies an AC voltage that varies positively and negatively to an electric field in the vicinity of a body surface of the worker 2 to extend a charged state of a human body, and thereby can make a longest distance of detection longer than a conventional structure using human body communication.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a personal protection device for protecting workers around an industrial robot from collision with the robot.

  2. Description of the Related Art In recent years, collaborative robots that perform work previously performed by humans on behalf of humans have been developed at industrial product manufacturing sites and the like in order to respond to the shortage of the working population and demands for improved product quality. Unlike conventional industrial robots, this collaborative robot is surrounded by safety fences, for example, it is placed in a process where a vacancy of workers has occurred in various work processes and works next to workers. Used without. For this reason, when a cooperative robot is used, an interpersonal protection device for protecting workers around the cooperative robot from collision with the cooperative robot is required.

  A personal protection device for a robot (hereinafter, also simply referred to as a “personal protection device”) has also been developed for a conventional industrial robot surrounded by a safety fence. When the worker carrying the transmitter approaches the robot when performing adjustment work inside the safety fence, the identification signal transmitted from the portable device is transmitted to the robot through human body communication, and the identification signal is received from the robot. There has been proposed a method in which a robot controller stops or decelerates a robot to prevent a collision between the robot and an operator.

  On the other hand, a collision prevention device (personal protection device) proposed in Patent Literature 2 is intended for a cooperative robot, and an electrode connected to a human body communication transmitter (signal transmitter) is mounted on a floor of a workplace. When a worker standing on the robot approaches the robot, the identification signal generated by the human body communication transmitter is transmitted from the electrode on the floor surface to the receiver on the robot side by human body communication and connected to the receiver. The robot controller is stopped by the robot.

JP 2010-188458 A JP 2013-193137 A

  The personal protection devices for robots proposed in Patent Documents 1 and 2 each use an electric field type human body communication technology, and can detect the approach of a worker and a robot by a very simple circuit method. it can.

  However, electric field-based human body communication uses the extremely small electrostatic field of the human body to signal when a communication partner enters an electrostatic layer that covers an area up to several cm from the surface of the human body. Because it is a transmission, the robot's personal protection device using this cannot detect the approach of both until the robot enters a distance within several cm from the worker's body surface, and the robot is operating at high speed In this case, even if the robot stops after detecting the approach between the robot and the worker, there is a possibility that collision between the two cannot be avoided.

  Further, in the personal protection device of Patent Document 2, it is necessary to install an electrode having a shape corresponding to the floor surface of the target cooperative robot every time the use location of the cooperative robot changes. There is also a problem that the work is troublesome.

  Therefore, an object of the present invention is to increase the distance that can detect the approach between a robot and an operator with a simple configuration that does not use floor electrodes in an interpersonal protection device using an electric field method of a cooperative robot. .

  In order to solve the above problems, the present invention provides an operation for avoiding contact between a robot and a worker working around the robot when the robot approaches the robot (hereinafter referred to as “contact avoidance”). In this case, an AC electric field held by the worker and applied to the vicinity of the body surface of the worker and having an absolute value larger than the static electric field of the human body, which fluctuates in the positive and negative directions, is applied to the apparatus. An AC voltage applying device, an electrode provided on the robot, and a measuring device for measuring a voltage at the electrode, wherein a signal is sent to a controller of the robot based on the voltage value measured by the measuring device to operate the robot. That is, the control is performed.

  In other words, in the conventional personal protection device using human body communication, the distance that the approach between the robot and the worker can be detected is short because the static electric field normally generated near the surface of the human body is small, and the movement of the muscles of the human body and Although it is considered that the charging state can be considered to be almost constant unless discharged, although it changes slightly depending on the surrounding charging state, the present invention provides a wearable AC voltage applied by the worker. By applying an alternating voltage that varies positively and negatively to the electric field near the worker's body surface with the device to increase the charged state of the human body, the distance at which the approach between the robot and the worker can be detected (hereinafter referred to as the “maximum detection distance”) ") Is made longer.

  In the conventional method, the longest detection distance is only about several cm, so that the contact avoidance operation of the robot is substantially limited to only the stop operation, whereas in the present invention, the longest detection distance is set as described above. Since the length can be increased, when the robot and the worker approach, the robot can perform an appropriate operation according to the detected distance among contact avoidance operations such as alarm transmission, deceleration, and stop.

  In addition, the electric field applied to the human body is not a DC electric field but an AC electric field that fluctuates positively and negatively, so that there is no danger of discharge from the human body to peripheral devices, and fluctuations in the electric field strength of the human body due to discharge can be eliminated. This eliminates the risk of noise and peripheral equipment failure or malfunction.

  Here, the AC voltage applied to the electric field in the vicinity of the body surface of the worker may be such that its effective value is higher than the static electric field at a level normally possessed by the human body, and more specifically, desirably 3 Vrms to 10 Vrms. If the effective value is lower than 3 Vrms, it is difficult to obtain a sufficient detection distance, and if the effective value is higher than 10 Vrms, the power consumption of the AC voltage adding device increases, and it is necessary to frequently perform charging, battery replacement, and the like. is there. If the effective value is 3 Vrms to 10 Vrms, the longest detection distance can be set to about 1 m.

  Further, the frequency of the AC voltage is not particularly limited, but is preferably several MHz to several tens MHz. If the frequency exceeds tens of MHz, the added voltage of the human body as an antenna is emitted to the outside as noise, and there is a concern that the human body will not be charged. This is because it is easy to do. When the frequency is set to several MHz to several tens of MHz, it becomes easy to distinguish from an AM wave of less than several MHz, various kinds of radio, FM broadcasting exceeding several tens of MHz, and external factors such as a wireless LAN. Therefore, for example, by providing a filter between the electrode and the measuring device so as to detect only the voltage information of the frequency of the AC voltage applying device, or by performing frequency analysis with the measuring device, the approach between the robot and the worker can be improved. Can be detected more accurately.

  By the way, even if the personal protection device having the above configuration is adopted, depending on the installation location of the robot, the ground potential may be 0 V even if the ground is taken on the measuring instrument side due to antistatic measures applied to the floor and the influence of insulating paint. In some cases, the reference potential differs between the AC voltage applying device and the measuring instrument, and it may be difficult to detect the distance between the robot and the worker. In addition, there are cases in which the worker also needs to move, and in some cases, it is difficult to take the ground. Further, the detection may be difficult due to the influence of the movement of the worker or the material of the clothes.

  In such a case, by connecting a ground electrode having an electrical length of ４ of the frequency of the AC voltage applying device to at least one of the AC voltage applying device and the measuring instrument, Regardless, the reference potential difference between the AC voltage applying device and the measuring instrument is eliminated, and the detection operation can be performed stably and accurately. In particular, since the ground potential on the worker side tends to be unstable, it is highly effective to make the ground electrode of the AC voltage applying device have a １ ／ electrical length. It is desirable that the ground electrode be adjusted to have an electrical length of 1/4 of the AC frequency when the operator holds the AC voltage applying device or is installed on the robot. Further, if necessary, a plurality of ground electrodes having the 1/4 electrical length can be connected in parallel so that a more stable detection operation can be performed.

  Since the present invention has the above-described configuration and operation, it can be particularly effectively applied to a case where the robot is a cooperative robot that performs a joint work with an operator.

  If the worker is provided with a plurality of the AC voltage applying devices, there is a possibility that the worker comes into contact with a plurality of robots, for example, when a cooperative robot is arranged on both sides of the worker. In addition, the approach between each robot and the worker can be detected. At this time, it is assumed that the plurality of AC voltage applying devices add AC voltages having different frequencies from each other, and if the measuring device measures the voltage of each frequency, the voltage of each frequency is compared. In addition, the accuracy of detecting the distance between each robot and the worker can be improved, and the posture of the worker can be estimated, so that the robot can be more precisely controlled for personal protection.

  On the other hand, if a device that can be worn on the head of the worker, such as a hat type or a helmet type, is adopted as the AC voltage applying device, there is almost no difference in electric field strength between the left and right sides of the worker's body, and the left and right sides are substantially equal. , It is easy to handle, for example, even in a work environment where the worker may contact the robot on the left and right, only one is needed. At this time, when a plurality of the workers are arranged around one robot, an AC voltage applying device attached to each worker applies AC voltages having different frequencies, and It is desirable to measure the voltage at the frequency of. When an AC voltage having the same frequency is applied to a plurality of workers, depending on the arrangement of the robot and the workers, the AC voltage charged to each worker affects each other, and the voltage value detected by the electrodes of the robot becomes excessive. It may be too small or too small.

  As described above, the anti-personnel protection device for a robot according to the present invention is an alternating-current voltage applying device held by an operator. And measures the voltage at the electrodes provided on the robot with a measuring instrument when the robot and the worker approach, and sends a signal to the robot controller based on the voltage value to control the operation of the robot. Therefore, the longest detection distance is longer than that using the conventional human body communication, and sufficient safety can be ensured even for a robot operating at high speed.

  In addition, since the voltage applied to the electric field near the worker's body surface is an alternating voltage that fluctuates positively and negatively, a discharge phenomenon between the worker and surrounding objects can be avoided, and the worker can also be in the vicinity. Can be used safely without causing discharge damage.

  In addition, since the AC voltage applying device is held by the operator and the electrodes and measuring instruments are provided on the robot side, the configuration is simpler than the conventional one using floor electrodes, and the place where the robot is used changes. However, it is unnecessary to change the shape of the electrodes or to perform the installation work, and the transfer of the robot can be performed efficiently.

Explanatory drawing of the basic configuration of the personal protection device of the present invention. Explanatory drawing of the basic configuration of the AC voltage application device of FIG. Front view of a robot to which the personal protection device of the first embodiment is applied Explanatory drawing of the planar positional relationship in the approach state of the robot of FIG. 3 and a worker. 3 is a graph illustrating a control method of the controller of FIG. The top view explaining the outline of the application state of the personal protective equipment of a 2nd embodiment. (A), (b) is a front view of a modification (hat type) of the AC voltage applying device, respectively. (A) is a front view of another modification (helmet type) of the AC voltage applying device, (b) is a partially cutaway front view of (a), and (c) is a component arrangement of (a) and (b). Front view of an example with changed The top view explaining the outline of the application state of the personal protective equipment of a 3rd embodiment.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. As shown in FIG. 1, the robot personal protection device of the present invention is held by an operator 2 (only the arm tip is shown) working around the robot 1, and changes in the electric field near the body surface of the operator 2 positively or negatively. And a measuring device 5 for measuring the voltage of the electrode 4. The measuring device 5 of the robot 1 It is connected to the controller 6. It is desirable that the measuring instrument 5 is connected to the ground electrode 7 as shown in the figure. Further, a general motor driver or controller is used for the controller 6.

  As shown in FIG. 2, the AC voltage applying device 3 is a wearable device that includes an AC current applying circuit 31, electrodes 32 and a ground electrode 33 connected thereto, and applies an AC voltage to the worker from the electrodes 32. In FIG. 1, a bracelet type worn on the wrist of the worker 2 is illustrated.

  The AC current adding circuit 31 includes a DC power supply 34, a switch 35, a stabilized power supply circuit 36, an oscillation circuit 37, and an RF amplifier circuit 38. The electrode 32 and the ground are provided on the output side of the RF amplifier circuit 38. The electrode 33 is connected. In this example, a 9 V dry battery is used as the DC power supply 34, the oscillation frequency of the oscillation circuit 37 is 12 MHz, and a +3.3 V stabilized power supply circuit 36 is incorporated to stabilize the power supplied to the oscillation circuit 37. , An alternating voltage of 9 V and 12 MHz is applied to the worker 2.

  In addition, the ground electrode 33 is wound around a resin bobbin 39 at a central portion thereof except for a connection portion to the AC current applying circuit 31 and a tip portion so that the ground electrode 33 can be compactly arranged. , The length and the like are adjusted so as to be と electrical length of the AC voltage frequency (12 MHz) added to the worker 2. By using the ground electrode 33 having a quarter electric length, the influence of external noise can be reduced.

  As the DC power supply, a rechargeable battery can be used in addition to a dry battery as in this example. If necessary, a DC-DC power supply circuit for increasing or decreasing the voltage of the DC power supply to an arbitrary level can be incorporated. On the other hand, depending on usage, the stabilized power supply circuit may be omitted, and the ground electrode may not have to have a 電 気 electrical length.

  By the action of the AC voltage applying device 3, the robot 1 and the worker are placed in a state in which an AC electric field having an absolute value larger or smaller than the static electric field of the human body is applied to the vicinity of the body surface of the worker 2. When the voltage of the electrode 4 on the robot 1 side increases due to the approach of the robot 2, a control signal for personal protection according to the voltage value measured by the measuring device 5 is sent to the controller 6, and the controller 6 transmits the measuring signal to the measuring device 5. The robot 1 is decelerated or stopped based on the control signal received from the robot 5.

  3 to 5 show a first embodiment of the present invention. As shown in FIG. 3, the robot 1 to which the personal protection device of the first embodiment is applied has a robot body 10 and a controller 6 mounted on an upper surface of a carriage 9 having a plurality of rollers 8 on a lower surface side. It is a cooperative robot that can move to various work places. As shown in FIG. 4, a bracelet-type AC voltage applying device 3 is mounted on a wrist of an operator 2 working in a state adjacent to the robot 1. The AC voltage applied by the AC voltage applying device 3 has an effective value of 3 Vrms to 10 Vrms and a frequency of several MHz to several tens MHz. The AC voltage applying device 3 may be provided with, for example, an LED lamp or the like so that it can be displayed that there is no problem with the power of the power supply.

  As shown in FIGS. 3 and 4, a robot body 10 of the robot 1 includes a base 11 fixed to an upper surface of a cart 9, and a first arm 12a rotatably mounted on an upper portion of the base 11 in a horizontal plane. And a second arm 12b that is rotatably mounted in the horizontal plane on the distal end of the first arm 12a. A first actuator 13a for rotating the first arm 12a is incorporated in an upper portion of the base 11, and a second actuator 13b for rotating the second arm 12b is incorporated in a tip portion of the first arm 12a. The end effector 14 is attached to the tip of the second arm 12b.

  Further, plate-like electrodes 4a and 4b are attached to the first arm 12a and the second arm 12b of the robot main body 10 one by one on the upper surface and on both side surfaces, respectively. Measuring instruments 5a and 5b connected to 4b are built in. Each of the measuring devices 5a and 5b is connected to the controller 6 and a ground electrode (not shown), and the ground electrode has an electrical length of 1/4 of the frequency of the AC voltage applying device 3.

  This personal protection device includes the above-described AC voltage applying device 3 on the worker 2 side, the electrodes 4a and 4b on the robot 1 side, and measuring devices 5a and 5b with ground electrodes. When the robot 1 approaches the worker 2, The voltage of the electrodes 4a and 4b on the robot 1 side rises, and the measuring devices 5a and 5b that measure the voltage send control signals corresponding to the voltage values to the controller 6 of the robot 1, and the controller 6 informs the robot 1 of the worker. An operation (contact avoidance operation) for avoiding contact with the device 2 is performed.

Here, assuming that the approaching distance between the worker 2 and the robot 1 (electrodes 4a, 4b) is A as shown in FIG. 4, as shown in FIG. The applied voltage is higher. Therefore, a threshold value of a voltage corresponding to the operation speed of each part of the robot 1 is set in advance for the measuring devices 5a and 5b, and the measuring devices 5a and 5b compare the measured voltage value with the set threshold value. , A control signal based on the comparison result may be sent to the controller 6. In the example shown in FIG. 5, to set the threshold _{V T1, V T2} of two stages, the voltage value measured is allowed to continue normal operation to the robot 1 is less than _{V T1,} is between _{V T1} and _{V T2} when is a low-speed operation by decelerating the robot 1, so that the robot is stopped 1 if it exceeds V _T2. In addition, when the measured voltage value is low, a warning (alarm transmission) is performed to the worker 2, and when the voltage value becomes high, the contact avoidance operation can be performed without stopping the robot 1. .

  As described above, this anti-personnel protection device uses the AC voltage applying device 3 held by the worker 2 to generate an AC electric field fluctuating in the positive and negative directions near the body surface of the worker 2 with an absolute value larger than the static electric field of the human body. When the robot 1 and the worker 2 approach each other, the voltages at the electrodes 4a and 4b provided on the robot 1 are measured by measuring devices 5a and 5b, and based on the voltage values, the voltage is sent to the controller 6 of the robot 1. Since the operation of the robot 1 is controlled by sending a signal, the longest detection distance is longer than that of the conventional robot using human body communication, and sufficient safety can be ensured even when the robot 1 operates at high speed. . In addition, the configuration is simpler than that using the conventional floor surface electrode, and even if the place of use of the robot 1 changes, the electrode shape change and installation work are not required, and the transfer of the robot 1 can be performed efficiently. it can.

  In this embodiment, the control signals corresponding to the voltage values measured by the measuring devices 5a and 5b are sent to the controller 6, but the measuring devices 5a and 5b send only the voltage value information to the controller 6, and The voltage value received in step 6 may be compared with the set threshold value, and the control of personal protection of the robot 1 may be performed based on the comparison result. At this time, the controller 6 identifies the voltage value information received from each of the measuring devices 5a and 5b, and determines from which direction the worker 2 approaches the first arm 12a or the second arm 12b of the robot 1. May be determined, and control may be performed for each of the arms 12a and 12b.

  On the other hand, when it is not necessary to precisely specify the part of the robot 1 approaching the worker 2, the voltage of each of the electrodes 4a and 4b may be measured by one measuring device.

  Further, it is desirable that the measuring instrument is provided with a ground electrode as in this embodiment so that the detecting operation can be performed stably and accurately regardless of the installation location of the robot. If it is considered that the reference potential of the AC voltage applying apparatus does not greatly differ from that of the AC voltage applying apparatus, the ground electrode can be omitted to reduce the cost.

  Further, in this embodiment, the AC voltage applying device 3 is attached to only one arm of the worker 2, but in this case, the voltage (electric field strength) charged to the human body by the AC voltage applying device is such that one arm has a higher strength than the other arm. And the distance that the proximity can be detected will be different between the left and right arms of the worker. Therefore, if the worker may approach the robot on both the left and right sides of the body, It is desirable to mount an AC voltage applying device on the arm) so that the approaching state between the worker and the robot can be detected more accurately.

  Further, as a modified example of the above-described first embodiment, a signal having a frequency higher than the frequency is superimposed on the signal of the AC voltage added by the AC voltage adding device 3, or modulation according to the signal is performed. Thus, signal information can be added. As the signal information to be added, for example, there is ID information capable of specifying an approaching worker. Then, while adding a filter to the measuring instrument, by adding a receiver and a data storage device connected to the measuring instrument, the signal information added from the voltage measured by the measuring instrument is separated and read by the filter, and the The signal information can be stored as data. In this way, when the approach between the robot and the worker is detected, the data stored in the data storage device is compared to identify the approaching worker in real time, and the contact according to the worker is determined. It is also possible to control the robot to perform the avoidance operation.

  FIG. 6 shows an applied state of the personal protective equipment of the second embodiment. In this embodiment, the worker 2 and the robot (cooperative robot) 1 'are alternately arranged along a horizontally long work table 15, and each worker 2 and each robot 2' The robot 1 'is applied. At this work site, work processes are different between the left side and the right side of the virtual line B shown in FIG.

  Each of the robots 1 ′ has a third arm 12 c mounted on an upper portion of the base 11 of the robot 1 of the first embodiment so as to be rotatable around the same axis as the first arm 12 a in a horizontal plane. A fourth arm 12d is attached to the tip of the arm 12c so as to be rotatable in a horizontal plane. Although not shown, the third and fourth arms 12c and 12d are also driven by actuators, similarly to the first and second arms 12a and 12d. Three are attached.

  On the other hand, each worker 2 wears one AC voltage applying device 3 on both arms (both wrists). The frequency of the AC voltage applying device 3 varies depending on the work process, and the frequency detected by the robot 1 ′ at the position (right side in FIG. 6) between the worker 2 in one process and the worker 2 in the other process is different. By performing the contact avoiding operation according to the above, it is possible to reliably prevent a collision with any of the left and right workers 2.

  Further, if the frequency of the AC voltage applying device 3 of each worker 2 is made different from each other, it is determined whether each robot 1 ′ may contact the worker 2 on the left or right side thereof, An appropriate contact avoiding operation can be performed by each robot 1 '.

  By the way, as described above, the bracelet type AC voltage applying device as used in the first and second embodiments is applied to both arms of the worker in a working environment where the worker may contact the robot from side to side. Although it is preferable to mount, in that case, the number of mounting becomes plural, and handling becomes somewhat complicated.

  On the other hand, if an AC voltage applying device that can be worn on the worker's head as described later is adopted, there is almost no difference in the electric field strength between the left and right sides of the worker's body, and the proximity detection is performed almost equally to the left and right Therefore, even in a work environment where the worker may contact the robot on the left and right, only one piece is required, and handling becomes easy.

  Further, when a ground electrode having a quarter electric length is used, if the ground electrode is mounted on a worker's head far from the ground, it is particularly hard to be affected by noise. The more the tip of the ground electrode of 1/4 electrical length can be placed farther from the other electrode and the body surface of the worker, and the closer it can be placed to the top of the worker's head, the lower the noise will be. This is preferable because the effect is enhanced.

  Hereinafter, an example of an AC voltage applying device that can be mounted on a worker's head will be described with reference to FIGS. 7 and 8. FIG. 7 shows an example of a hat type AC voltage applying device 16 having a brim. In the example of FIG. 7A, an AC current adding circuit 18 is attached to the outer surface of the rear part of the crown (body) of the hat 17, and a thin plate-shaped inner surface near the top of the crown of the hat 17 is provided. Electrodes 19 are attached. The ground electrode 20 having a quarter electric length has a length of 6 to 8 m when the frequency of the AC voltage applied to the operator is 12 MHz. A bobbin having a central portion wound around a resin bobbin having a diameter of 12 mm except for 70 cm is prepared, and the bobbin wound portion 20 a is fixed to the outer surface of the crown portion of the hat 17. Wrapped around the part.

  In the example of FIG. 7B, the mounting position of the AC current adding circuit 18 is the same as that of FIG. 7A, but the electrode 19 is positioned at the position of the slip (headband) on the inner surface of the crown portion of the cap 17. , The adhesion of the electrode 19 to the operator's head is improved. The ground electrode 20 having a 1/4 electrical length has the bobbin winding portion 20a fixed to the outer surface of the crown portion of the hat 17 as in FIG. It is wrapped around the top of the head.

  The surface of the electrode 19 may be coated with a resin in order to prevent rust due to sweat and to prevent injury when the cap 17 is covered. If the voltage application is not hindered, the cap 17 may be placed anywhere on the crown.

  FIG. 8 shows an example of a helmet type AC voltage applying device 21. 8 (a) and 8 (b), an AC current adding circuit 23 is attached to the outer surface of the rear portion of the cap 22 and the inner surface near the top of the hammock 24 set in the cap 22. The electrode 25 is attached to. The ground electrode 26 having a 1/4 electrical length has its bobbin winding portion 26a fixed to the outer surface of the cap 22 and its front end wound toward the top of the cap 22.

  As described above, in the helmet-type AC voltage applying apparatus 21, even if both the tip of the electrode 25 and the tip of the ground electrode 26 are provided near the top of the cap 22, the hammock 24 and the shock absorbing liner 27 are provided therebetween. Is provided and a sufficient distance is secured, so that the influence of noise is small.

  In the example of FIG. 8C, the mounting position of the electrode 25 is the same as that of FIGS. 8A and 8B, but the mounting position of the AC current applying circuit 23 and the bobbin winding portion 26 a of the ground electrode 26. 8 (a) and 8 (b), the tip of the ground electrode 26 is arranged at the brim of the cap 22 to increase the distance between the electrode 25 and the ground electrode 26. The influence of noise is further reduced.

  FIG. 9 shows an applied state of the personal protective equipment of the third embodiment. In this embodiment, the worker 2 and the robot 1 'at the same work site as the second embodiment shown in FIG. 6 are applied, and each worker 2 is provided with a helmet type shown in FIGS. 8A and 8B. The AC voltage applying device 21 of FIG.

  Then, the frequency of the AC voltage applying device 21 of each worker 2 is set to a different value, and the measuring instrument measures the voltage for each frequency using the frequency analysis, and the largest voltage among the measured voltages is measured. By transmitting a control signal for controlling the operation of the robot 1 'according to the value to the control device of the robot 1', each robot 1 'performs a contact avoidance operation according to the detected frequency.

  At this time, since the frequency of the AC voltage applied to each worker 2 is different from each other, the voltage value detected by the electrode of the robot 1 ′ is set to an appropriate range regardless of the arrangement of the robot 1 ′ and the worker 2. Can be suppressed.

  The embodiments disclosed this time are to be considered in all respects as illustrative and not restrictive. The scope of the present invention is defined by the terms of the claims, rather than the description above, and is intended to include any modifications within the scope and meaning equivalent to the terms of the claims.

  For example, the AC voltage applying device may be a bracelet type, a hat type, or a helmet type as described in the embodiment, or may be formed in a card shape and placed at an arbitrary position on a worker's body (for example, a work clothes or a belt). Etc.). The electrodes are usually attached to an operation unit such as a robot arm, but the robot body itself may be used as the electrodes.

  The present invention can be applied particularly effectively when the target robot is a cooperative robot as in each of the above-described embodiments. However, the present invention is applicable to a conventional industrial robot and a worker who performs adjustment work, maintenance, and the like. It can also be applied to prevent a collision when the worker works around the robot.

1, 1 'robot (collaborative robot)
2 Worker 3, 16, 21 AC voltage applying device 4, 4a, 4b Electrode 5, 5a, 5b (of robot) Measuring device 6 Controller 7 Ground electrode (of measuring device) 10 Robot body 12a, 12b, 12c, 12d Arm 17 Hat 18, 23, 31 AC current applying circuit 19, 25, 32 Electrode 20, 26, 33 (of AC voltage applying device) Ground electrode 22 (of AC voltage applying device) Cap

Claims (7)

When a robot and a worker working around the robot approach, in a personal protection device for a robot that causes the robot to perform an operation for avoiding contact with the worker,
An AC voltage applying device that is held by the worker and that applies an AC electric field that fluctuates in the positive and negative directions with an absolute value larger than the electrostatic field of the human body near the body surface of the worker, and an electrode provided in the robot, And a measuring device for measuring a voltage at the electrode, wherein a signal is sent to a controller of the robot based on the voltage value measured by the measuring device to control the operation of the robot.   The personal protection of the robot according to claim 1, wherein a ground electrode having an electrical length of 1/4 of the frequency of the AC voltage applying device is connected to at least one of the AC voltage applying device and the measuring device. apparatus.   The apparatus according to claim 1, wherein the robot is a cooperative robot that performs joint work with a worker.   The personal protection device for a robot according to any one of claims 1 to 3, wherein a plurality of the AC voltage applying devices are held by an operator.   5. The apparatus according to claim 4, wherein the plurality of AC voltage applying devices apply AC voltages having different frequencies from each other, and the measuring devices measure voltages having respective frequencies. 6.   The personal protection device for a robot according to any one of claims 1 to 3, wherein the AC voltage applying device is attachable to a head of the worker.   A plurality of the workers are arranged around one robot, and an AC voltage applying device attached to each worker applies an AC voltage having a different frequency from each other. The personal protection device for a robot according to claim 6, wherein the measurement is performed.

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