JP7357835B2 - object detection device - Google Patents

Description

The present invention relates to an object detection device, and particularly to one in which an object detection sensor section can be easily arranged regardless of the shape of the installation location.

A conventional object detection device will be explained using an object detection device 100P shown in FIG. 17. The object detection device 100P includes a plurality of optical sensor units SU and one central control section 115P. Each optical sensor unit SU has a plurality of optical sensor sections 111P and one unit control section 113P. In each optical sensor unit SU, a plurality of optical sensor sections 111P and one unit control section 113P are connected in a star shape via an optical sensor connection line L111. The unit control sections 113P belonging to one group line GL are connected in a cascade manner via a unit control section connection line L113. One of the unit control sections 113P connected in a cascade type is connected to the central control section 115P via a unit control section connection line L113. In this way, by using the flexible unit control unit connection line L113, the optical sensor unit SU can be freely arranged according to the shape of the installation location. Additionally, the detection range at the installation location can be freely set. Therefore, it becomes possible to detect objects in space, and the detection range can be set freely.

The industrial robot 50 to which the object detection device 100P is used is a robot having seven movable axes. The industrial robot 50 has arms AM1 to AM7, movable rotary joints J1 to J13, a base B1, and a hand H1. An object detection device 100P is arranged on each outer peripheral surface of the arms AM1 to AM7, hand H1, and base B1.

One unit control section and a plurality of optical sensor sections 111 are arranged in each of the arms AM1 to AM7, the base B1, and the hand H1. As shown in FIG. 17, the optical sensor section 111 can be placed at any location, such as arms AM1 to AM7, hand H1, base B1, etc., regardless of the shape of the installation location. In this way, the optical sensor section 111P can be easily placed on the outer surface of the device on which the object detection device 100P is installed, so that when an object such as a person is detected around the industrial robot, the robot can be It is possible to make an emergency stop. In other words, the safety of the installation target device, for example, an industrial robot, can be improved.

Furthermore, by adjusting the length of the optical sensor connection line L111, the optical sensor section 111P can be placed at any position. Therefore, regardless of the shape of the installation location, such as the prismatic arms AM1 to AM7 or the cylindrical base B1, the optical sensor section 111 can be placed all around. As a result, objects such as people can be detected on the entire periphery of the robot, thereby increasing the safety of the device to be installed.

Furthermore, even if the hand H1 has a complicated shape, the optical sensor section 111P can be freely arranged. Therefore, it is possible to prevent the occurrence of a blind spot when arranging the optical sensor section 111, thereby increasing the safety of the installation target device.

Furthermore, even if there is an obstacle between the arms AM1 to AM7 where the optical sensor section 111P is arranged, such as the movable rotary joints J1 to J13, by adjusting the length of the unit control section connection line L113, , the unit control sections 113P can be connected to each other while avoiding obstacles. In this way, the object detection device 100P can be freely arranged regardless of the shape of the device.

In the object detection device 100P, no matter how it is installed, the number and arrangement positions of the optical sensor section 111P and the unit control section 113P, and the lengths of the optical sensor connection line L111 and the unit control section connection line L113 are fixed. The object detection device can be easily placed by simply adjusting the In addition, the object detection device 100P adjusts the installation position of the optical sensor section 111P and the unit control section 113P according to changes in the installation environment, such as changes in the detection position, detection range, installation position, and shape of the installation target device. It is possible to easily respond to changes in the installation environment by changing the number of installations or adding or reducing the number of installations (see Patent Document 1 above).

JP2013-83615A

The object detection device 100P described above has the following points to be improved. In the object detection device 100P, different optical sensor units 111P are arranged to face each other in the industrial robot 50, or different optical sensor units 111P are arranged to face each other as the industrial robot 50 operates. It may be located. When different optical sensor units 111P are located facing each other, detection light emitted by a light emitting element (not shown) of one optical sensor unit 111P is received by the other optical sensor unit 111P located opposite to each other. There is an issue that needs to be improved in that the light may be directly received by an element (not shown) and accurate detection may not be possible.

Note that the following may be considered as the reason why the object detection device 100P cannot accurately detect the object. In the optical sensor units 111P located opposite to each other, the other light receiving element receives the detection light emitted by one of the light emitting elements. It is light. For this reason, the object detection device 100P detects the distance to the object based on the time from the projection of the detection light by the light emitting element to the reception of the reflected light by the corresponding light receiving element, that is, the time taken to travel back and forth to the object to be detected. , the distance to the object cannot be detected accurately.

Furthermore, since the light receiving element uses direct detection light projected by the light projecting element, the light intensity is too strong and overflows at the light receiving element, making it impossible to accurately detect the distance to the object.

SUMMARY OF THE INVENTION Therefore, an object of the present invention is to provide an object detection device that can accurately detect an object without being affected by the arrangement positions of a light projecting element that projects detection light and a light receiving element that receives reflected light.

The means for solving the problems of the present invention and the effects of the invention are shown below.

The object detection device according to the present invention includes a detection light projecting section that projects a detection light, and a reflected light receiving section that receives reflected light of the detection light, and the object detection device is arranged to correspond to the detection light projecting section. a plurality of object detection sensor sections each having a reflected light receiving section, the reflected light receiving sections not receiving the detection light emitted by the detection light projecting sections other than the corresponding detection light projecting section; , a control section that executes a detection process in which the detection light projecting section projects the detection light and puts the reflected light receiving section in a standby state for receiving the reflected light.

This can prevent the reflected light receiver from receiving detection light projected by a detection light projector other than the corresponding detection light projector, and can prevent erroneous reception of the detection light. Therefore, the object detection device can accurately detect an object without being influenced by the arrangement positions of the light projecting element that projects the detection light and the light receiving element that receives the reflected light.

In the object detection device according to the present invention, the control unit may cause the first detection light projector that has projected the detection light to transmit the detection light in addition to the detection light projected by the first detection light projector. If there is a possibility that the corresponding reflected light receiver receives the detection light projected by the second detection light projector, the first detection light projector and the second detection light Using sensor group information in which the light projecting unit and the light projecting unit are in a different group, the detection light projecting unit in the same group projects the detection light, and the detection light projecting unit that projects the detection light continues until after a predetermined period of time has elapsed. The method is characterized in that the detection process is executed to place the reflected light receiver corresponding to the light projector in a standby state for receiving the reflected light.

As a result, simply by using the sensor group information, it is possible to easily prevent the reflected light receiver from receiving detection light emitted by a detection light emitter other than the corresponding detection light emitter, and Erroneous light reception can be prevented. Therefore, the object detection device can accurately detect an object without being influenced by the arrangement positions of the light projecting element that projects the detection light and the light receiving element that receives the reflected light.

The object detection device according to the present invention is characterized in that the control unit controls the detection light projecting units belonging to the same group to simultaneously project the detection light.

Thereby, even when sensor group information is used, detection processing can be executed in a short time.

In the object detection device according to the present invention, the control unit suspends operation of the object detection sensor unit that belongs to the group different from the group when the detection process regarding the certain group is being executed; It is characterized by

This makes it possible to reliably prevent false detections between different groups.

In the object detection device according to the present invention, the control section operates the detection light projection section and the reflected light reception section for a predetermined period of time, so that the first detection light projection section emits light. In addition to the detection light, the reflected light receiving section corresponding to the first detection light projecting section that projects the detection light receives the detection light that is projected by the second detection light projecting section. In this case, the present invention is characterized in that sensor group information is generated in which the first sensing light projecting section and the second sensing light projecting section are classified into different groups.

This allows sensor group information to be automatically generated, making it easier to prevent incorrect reception of detection light, which is influenced by the placement position of the light emitting element that emits the detection light and the light receiving element that receives the reflected light. Objects can be detected accurately without any interference.

In the object detection device according to the present invention, the control section may cause one of the detection light projecting sections to project the detection light, and the corresponding reflected light receiving section may be configured to transmit the A feature of the present invention is that the detection process for setting the device in a light receiving standby state is executed.

Thereby, it is possible to easily prevent the reflected light receiving section from receiving the detection light projected by a detection light projecting section other than the corresponding detection light projecting section, and it is possible to prevent the erroneous reception of the detection light. Therefore, the object detection device can accurately detect an object without being influenced by the arrangement positions of the light projecting element that projects the detection light and the light receiving element that receives the reflected light.

1 is a diagram showing a state in which an object detection device 100, which is an embodiment of an object detection device according to the present invention, is arranged on an industrial robot RBT. 1 is a diagram showing the configuration of an object detection device 100. FIG. 3 is a diagram showing the hardware configuration of an object detection sensor section 113. FIG. 2 is a diagram showing a hardware configuration of a control unit 117. FIG. It is a figure showing operation of industrial robot RBT. This shows sensor group information. FIG. 3 is a timing chart showing the operation state of the object detection device 100. FIG. 3 is a flowchart showing the operation of the object detection device 100. 1 is a diagram showing a state in which an object detection device 200, which is an embodiment of an object detection device according to the present invention, is arranged on an industrial robot RBT. FIG. 3 is a timing chart showing the operation state of the object detection device 100. FIG. 3 is a flowchart showing the operation of the object detection device 100. FIG. 3 is a diagram showing a state in which an object detection device 300, which is an embodiment of the object detection device according to the present invention, is arranged on an industrial robot RBT. 3 is a flowchart showing the operation of the object detection device 300. It is a figure which shows the other Example of an object detection apparatus. It is a figure which shows the other Example of an object detection apparatus. It is a figure which shows the other Example of an object detection apparatus. FIG. 1 is a diagram showing a conventional object detection device.

Embodiments of the present invention will be described in detail below with reference to the drawings.

An object detection device according to the present invention will be explained using an object detection device 100 shown in FIG. 1 as an example. The object detection device 100 detects whether or not an object exists in the surroundings, and performs a predetermined operation based on the object detection result.

First configuration 1. Industrial Robot The industrial robot RBT in which the object detection device 100 is arranged will be described using FIG. 1. An object detection device 100 is placed on the outer surface of the industrial robot RBT. The industrial robot RBT is a robot having five movable axes. The industrial robot RBT has arms AM1 to AM7, a rotating base B, and a hand H. Each of the arms AM1 to AM7 has a rotary joint having a rotation axis in the longitudinal direction of the arm at one end, and a rotary joint having a rotation axis in the short direction of the arm at the other end. The hand H1 has a movable holding part for holding an object at its tip.

The object detection device 100 includes a plurality of object detection sensor units 111, a control section 117, and a connection harness 119. The object detection sensor unit 111 is arranged along the outer circumferential surfaces of the arms AM1 to AM7, the rotating base B, and the hand H, and detects detection target objects existing around them. Note that the object detection sensor unit 111 detects the object to be detected by measuring the distance to the object to be detected.

The object detection sensor unit 111 is connected to the control section 117 via a connection harness 119. Further, the control unit 117 is connected to a power source (not shown) that operates each rotary joint of the industrial robot RBT. The control unit 117 controls the operations of the arms AM1 to AM7, the rotating base B, and the hand H by controlling the operations of the power sources.

2. Object detection device 100
The object detection device 100 will be explained using FIG. 2. The object detection device 100 includes a plurality of object detection sensor units 111, a control section 117, and a connection harness 119. The object detection sensor unit 111 includes a plurality of object detection sensor sections 113 and a sensor arrangement flexible member 115.

The object detection sensor unit 113 projects a predetermined light as detection light and receives the reflection of the detection light to measure the distance to the object and detect whether or not the object exists. The hardware configuration of the object detection sensor section 113 is shown in FIG.

The object detection sensor section 113 includes a light projecting element 113a, a light projecting lens 113b, a light receiving element 113c, and a sensor communication circuit 113d. The light projecting element 113a projects predetermined detection light, for example, near-infrared light. The light projection lens 113b diffuses the detection light projected by the light projection element 113a into a predetermined range (detection region R113). The light-receiving element 113c receives the detection light emitted by the light-emitting element 113a and reflected by an object.

As the light projecting element 113a, for example, a near-infrared LED (Light Emitting Diode) or the like can be used. As the light receiving element 113c, for example, a SPAD (Single Photon Avalanche Diode) can be used.

In SPAD, when the reflected light of the detection light is received, the carriers generated by the received reflected light are converted into electrical pulses using avalanche amplification, and the time of light reception is measured using a TDC (Time to Digital Converter). . When SPAD receives reflected light, it uses the time when the light emitting element 113a emits the detection light and the measured reception time of the reflected light to determine the time from the emission of the detection light to the reception of the reflected light. A certain object detection time is calculated and transmitted as detection information to the sensor communication circuit 113d. Note that if the light-receiving element 113c does not receive reflected light within a predetermined period of time or if it captures an insufficient amount of light (number of photons) to accurately calculate the distance to the object, the light receiving element 113c performs measurement. Detection information indicating that an object cannot be detected within the possible range is transmitted to the sensor communication circuit 113d.

The sensor communication circuit 113d is connected to the sensor control communication circuit 117g of the control section 117, so that the object detection sensor section 113 and the control section 117 can communicate with each other. Note that the sensor communication circuit 113d of each object detection sensor section 113 is connected directly, that is, in parallel, to the control section 117.

In this way, the object detection sensor section 113 detects an object or person that has entered within an arbitrary set distance from the industrial robot RBT in which the object detection sensor section 113 is arranged by detecting the distance to the object. As a result, the operation of the industrial robot RBT can be controlled based on the distance from the industrial robot RBT.

Returning to FIG. 2, the sensor placement flexible member 115 is a flexible member that can be placed along the surface of the object to which it is attached. For example, a thin rubber plate can be used as a material for forming the sensor arrangement flexible member 115. The object detection sensor sections 113 are arranged on the sensor arrangement flexible member 115 at predetermined intervals. The object detection sensor section 113 is fixed to the sensor arrangement flexible member 115 using a predetermined fixing means such as a predetermined fixing member, adhesive, or screw.

The control unit 117 receives detection information from each object detection sensor unit 113 via the connection harness 119. The control unit 117 controls the light emitting element 113a of each object detection sensor section 113 of each object detection sensor unit 111 to emit detection light at a predetermined timing, and also transmits detection information from the light receiving element 113c. get.

The hardware configuration of the control unit 117 will be explained using FIG. 4. The control unit 117 includes a CPU 117a, a memory 117b, a sensor control communication circuit 117g, and an operation control communication circuit 117h.

The CPU 117a performs processing based on the operating system (OS), sensor control program, and other applications recorded in the memory 117b. The memory 117b provides a work area for the CPU 117a, and records and holds various data such as an operating system (OS), other application programs such as a sensor control program, and sensor group information (described later).

The sensor control communication circuit 117g is connected to the sensor communication circuit 113d (see FIG. 3) of the object detection sensor section 113 via the connection harness 119 (see FIG. 2), and transmits and receives information between the two. Note that the sensor control communication circuit 117g is connected to each of the object detection sensor units 113 directly, that is, in parallel. The operation control communication circuit 117h is connected to an object whose operation is to be controlled based on detection of the presence of an object by the object detection sensor unit 111, and transmits and receives information between the two.

Returning to FIG. 2, the connection harness 119 directly connects each object detection sensor section 113 and the control section 117. That is, the connection harness 119 is a connection line for connecting each object detection sensor section 113 to the control section 117 in parallel.

Second Operation of Sensor Control Program The operation of the CPU 117a based on the sensor control program will be described below.

1. Grouping of Object Detection Sensor Units 113 The object detection sensor units 111 included in the object detection device 100 are grouped according to the following conditions. In the object detection device 100, by grouping the object detection sensor units 111, the object detection sensor sections 113 belonging to the object detection sensor units 111 are also grouped. In the object detection sensor section 113 of the object detection sensor unit 111 disposed in the industrial robot RBT, as the industrial robot RBT moves, other objects are detected in addition to the detection light emitted by the light emitting element 113a of the industrial robot RBT. The object detection sensor unit 111 is determined based on whether or not there is a possibility that the light emitting element 113a of the object detection sensor section 113 of the detection sensor unit 111 will receive the detection light emitted by the light emitting element 113a and become unable to normally detect an object. Group.

In addition, in the following, in the object detection sensor section 113 of the object detection sensor unit 111 disposed in the industrial robot RBT, as the industrial robot RBT operates, in addition to the detection light emitted by the light projecting element 113a that the industrial robot RBT has, , the light-receiving element 113c corresponding to the light-emitting element 113a of the other object-detection sensor unit 111 receives the detection light emitted by the light-emitting element 113a of the object-detection sensor section 113 of the other object-detection sensor unit 111. There is a possibility that the object detection sensor units 111 will not be able to perform normal object detection, which is referred to as "interference between the object detection sensor units 111," and the absence of such a possibility is referred to as "the object detection sensor units 111 do not interfere with each other." That's it.

For example, in the industrial robot RBT shown in FIG. 1, as shown in FIG. 5, there are cases where the rotary base B, arm AM1, arm AM7, and hand H are located facing each other. Therefore, the rotating base B, the arm AM1, the arm AM7, and the hand H "interfere". Therefore, the rotating base B, the arm AM1, the arm AM7, and the hand H are grouped so that they belong to different groups. Note that the group to which rotating base B and arm AM1 belong is group X, and the group to which arm AM7 and hand H belongs is group Y.

On the other hand, arms AM3 and AM5 "do not interfere" with rotary base B and arm AM1, and also "do not interfere" with arm AM7 and hand H. Therefore, although arms AM3 and AM5 may belong to either group X or group Y, they are assigned to group X here.

Information describing the grouping of the object detection sensor units 111 is stored and held in the memory 117b as sensor group information. Sensor group information is shown in FIG. The sensor group information includes a target object detection sensor unit description section and a group description area. Identification information of the object detection sensor unit 111 placed in the industrial robot RBT is described in the target object detection sensor unit description section. The group description area describes the group to which the object detection sensor unit 111 identified by the identification information described in the corresponding target object detection sensor unit description section belongs. The sensor group information in FIG. 6 indicates, for example, that the object detection sensor unit 111 disposed on the arm AM1 identified by the identifier "A1" belongs to the group "X".

Since the object detection sensor units 111 belonging to the same group "do not interfere" with each other, they simultaneously emit detection light and perform a detection process to determine whether or not to receive reflected light of the detection light. Note that while the object detection sensor units 111 belonging to one group are executing the detection process, the object detection sensor units 111 belonging to the other groups do not execute the detection processes and are put on pause. After executing the detection process in one group, the same detection process is executed in another group.

For example, as shown in the timing chart shown in FIG. Since the detection processing starts at the same time, the detection processing can be performed in a shorter time than when each object detection sensor section 113 sequentially executes the detection processing. Moreover, since detection processing is performed sequentially between different groups and no duplicate detection processing is performed, erroneous reception of detection light does not occur between different object detection sensor units 111. Therefore, malfunctions in the object detection sensor unit 111 can be prevented.

Note that when switching groups, time for starting up the object detection sensor section 113 and switching time for stopping the object detection sensor section 113 are required, but each object detection sensor section 113 is operated in sequence. Since the number of times of switching can be reduced compared to the case where the detection process is executed in advance, the overall detection process can be executed in a short time.

2. Flowchart The object detection process based on the sensor control program executed by the CPU 117a will be described using the flowchart shown in FIG. The CPU 117a acquires sensor group information from the memory 117b (S701). The CPU 117a selects one of the groups described in the sensor group information as a detection target group (S703).

The CPU 117a selects one object detection sensor unit 111 belonging to the detection target group as a detection target sensor unit (S705). The CPU 117a emits detection light to the light emitting elements 113a of all the object detection sensor sections 113 belonging to the detection target sensor unit, and puts the corresponding light receiving elements 113c in a waiting state for receiving reflected light of the detection light. Detection start information SS (see FIG. 7) indicating that the detection start information SS (see FIG. 7) is to be transmitted is sent all at once via the sensor control communication circuit 117g (see FIG. 4) and the sensor communication circuit 113d (see FIG. 3) (S707). Note that which object detection sensor section 113 belongs to which object detection sensor unit 111 is stored and held as sensor information in the memory 117b.

When the light emitting element 113a of the object detection sensor section 113 acquires the detection start information, it emits detection light, and the light receiving element 113c enters a light reception standby state. The light receiving element 113c, which has received the reflected light of the detection light emitted by the light emitting element 113a corresponding to itself, sends detection information containing the object detection time, which is the time from the emission of the detection light to the reception of the reflected light. On the other hand, if no reflected light is received within a predetermined time, or if an insufficient amount of light (number of photons) is captured to accurately calculate the distance to the object, the object may be within the measurable range. Detection information indicating that the sensor cannot be detected is transmitted to the CPU 117a via the sensor communication circuit 113d (see FIG. 3) and the sensor control communication circuit 117g (see FIG. 4).

Upon receiving the detection information (S709), the CPU 117a determines whether the content of the detection information is an object detection time (S711). When determining that the content of the detection information is the object detection time, the CPU 117a calculates the distance to the object to be detected from the acquired object detection time (S713). In calculating the distance to the object to be detected, the speed of the detection light is used to calculate the object detection time, which corresponds to the round trip time of the detection light to the object to be detected. Data necessary for calculating the distance to the object to be detected is stored in advance in the memory 117b.

The CPU 117a determines whether the calculated distance to the detection target object is less than the operation stop distance (S715). The operation stop distance is a distance to a detected object for which the control unit 117 determines that it is necessary to stop the operation of the industrial robot RBT whose operation is to be controlled. The operation stop distance is set for each object detection sensor section 113. Note that the operation stop distance is stored and held in the memory 117b.

When the CPU 117a determines that the calculated distance to the object to be detected is less than the operation stop distance, the CPU 117a transmits operation stop information for stopping the operation to the drive device that operates the industrial robot RBT (S717). When the CPU 117a acquires operation restart information after stopping the operation of the industrial robot RBT (S719), the CPU 117a restarts the detection process if the detection process is not finished (S729).

When the CPU 117a determines that the distance to the object to be detected calculated in step S715 is not less than the operation stop distance, that is, there is no object in the predetermined surroundings of the industrial robot RBT, the CPU 117a detects all objects of the sensor unit to be detected. Regarding the sensor unit 113, it is determined whether the processes from steps S709 to S715 have been executed (S721).

When the CPU 117a determines that the processes from steps S709 to S715 have been executed for all object detection sensor units 113 of the detection target sensor units, the CPU 117a executes the processes from steps S707 to S721 with all the object detection sensor units 111 as detection target sensor units. It is determined whether or not it has been executed (S723). If the CPU 117a determines in step S723 that the processes of steps S709 to S721 have not been executed with all the object detection sensor units 111 as detection target sensor units, the CPU 117a executes the processes of steps S709 to S721 for the remaining object detection sensor units 111. The process is executed and detection start information is transmitted to all object detection sensor units 111 belonging to one group.

When the CPU 117a determines that the predetermined interval period IT (see FIG. 7) has elapsed (S725), the CPU 117a determines whether the processes of steps S705 to S725 have been executed with all groups as detection target groups (S727). Note that the interval period IT is the time required to start the next measurement, and is based on the performance of the object detection sensor unit 113, the distance between the object detection sensor unit 111 and the control unit 117, and the distance between the object detection sensor unit 111 and the control unit. It is determined in advance in consideration of the communication method with the unit 117, the communication environment, etc., and is stored and held in the memory 117b.

If the CPU 117a determines in step S727 that the processes of steps S703 to S725 have been executed with all groups as detection target groups, if the detection process is not finished (S729), all groups placed on the industrial robot RBT Assuming that the detection processing for the object detection sensor unit 111 has been performed, that is, the detection processing for the object detection sensor unit 111 has been performed one round, the detection processing for the next round is executed.

On the other hand, if the CPU 117a determines in step S727 that the processes of steps S705 to S725 have not been executed with all groups as detection target groups, it executes the processes of steps S705 to S725 for one other group. In other words, the CPU 117a determines that the object detection process for one group has ended, and starts the object detection process for another different group. For example, as shown in FIG. 7, it is determined that the object detection process for group X has ended, and object detection process for group Y, which is different from group X, is executed.

In the object detection device 100 according to the first embodiment described above, the sensor group information is used to prevent the light receiving element 113c from receiving detection light emitted by light emitting elements 113a other than the corresponding light emitting element 113a. . On the other hand, the object detection device 200 according to this embodiment prevents the light receiving element 113c from receiving detection light emitted by light emitting elements 113a other than the corresponding light emitting element 113a, without using sensor group information. It is something. In addition, in the following, the same reference numerals are given to the same configurations as in the first embodiment, and detailed explanations are omitted.

First Configuration The configuration of the object detection device 200 will be described using FIG. 9. FIG. 9 shows a state in which the object detection device 200 is placed on an industrial robot RBT. The object detection device 200 includes a plurality of object detection sensor units 111, a control section 117, and a connection harness 119. Each configuration of the object detection device 200 is the same as the configuration in Example 1 (see FIGS. 1 to 4).

Second Operation of Sensor Control Program The operation of the CPU 117a based on the sensor control program in the object detection device 200 will be described below.

1. Sequential Detection In the object detection device 200, the object detection processing in all the object detection sensor units 113 included in the object detection device 200 is performed sequentially without using sensor group information so as not to “interfere” with each other. That is, as shown in FIG. 10, the detection start information SS is transmitted to the object detection sensor section 113, the light emitting element 113a emits the detection light, and the light receiving element 113c receives the reflected light during the effective light reception period RT. The detection process is sequentially executed for all object detection sensor units 113.

2. Flowchart The object detection process based on the sensor control program executed by the CPU 117a of the object detection device 200 will be described using the flowchart shown in FIG. The CPU 117a selects one object detection sensor unit 111 as a detection target sensor unit (S1001). The CPU 117a selects one object detection sensor unit 113 belonging to the detection target sensor unit as the detection target sensor unit (S1003).

The CPU 117a emits detection light to the light emitting element 113a of the sensor unit to be detected, and sends detection start information SS to the corresponding light receiving element 113c, indicating that it is in a standby state for receiving reflected light of the detection light. (see FIG. 10) is transmitted (S1005). Note that which object detection sensor section 113 belongs to which object detection sensor unit 111 is stored and held as sensor information in the memory 117b.

When the light receiving element 113c corresponding to the light emitting element 113a that emits the detection light receives the reflected light of the detection light, the light receiving element 113c detects the object detection time, which is the time from the emission of the detection light to the reception of the reflected light. On the other hand, if no reflected light is received within the specified time, or if an insufficient amount of light (number of photons) is captured to accurately calculate the distance to the object, Detection information indicating that the object cannot be detected is transmitted to the CPU 117a via the sensor communication circuit 113d (see FIG. 3) and the sensor control communication circuit 117g (see FIG. 4).

Upon receiving the detection information (S1007), the CPU 117a executes the processes of steps S711 to S719. Note that the processes from step S711 to step S719 are the same as in the first embodiment, so detailed description will be omitted.

When the CPU 117a determines that the distance to the object to be detected calculated in step S715 is not less than the operation stop distance, that is, there is no object around the industrial robot RBT, the CPU 117a determines whether a predetermined interval time has elapsed. It is determined whether or not (S1009).

When the CPU 117a determines that the predetermined interval time has elapsed, the CPU 117a determines whether the processes of steps S1007, S1009, and S711 to S715 have been executed for all detection target sensor units of the detection target unit (S1011). If the CPU 117a determines in step S1011 that the processes of steps S1007, S1009, and S711 to S715 have not been executed with all the object detection sensor units 113 as detection target sensor units, the CPU 117a executes the steps for the remaining object detection sensor units 113. The processes of S1007, S1009, and S711 to S715 are executed.

If the CPU 117a determines in step S1011 that the processes of steps S1007, S1009, and S711 to S715 have been executed with all object detection sensor units 113 as detection target sensor units, it sets all object detection sensor units 111 as detection target sensor units. It is determined whether steps S1003 to S1011 and S711 to S715 have been executed (S1013). If the CPU 117a determines in step S1013 that the processes of steps S1003 to S1011 and S711 to S715 have not been executed with all the object detection sensor units 111 as detection target sensor units, if the detection process is not completed (S729), Assuming that the detection process has been executed for all the object detection sensor units 111 arranged in the industrial robot RBT, that is, the detection process in the object detection sensor unit 111 has completed one round, the detection process for the next round is executed.

In the object detection device 100 according to the first embodiment described above, object detection was performed using preset sensor group information. On the other hand, the object detection device 300 according to this embodiment automatically generates sensor group information. In addition, in the following, the same reference numerals are given to the same configurations as in the first embodiment, and detailed explanations are omitted.

First Configuration The configuration of the object detection device 300 will be described using FIG. 12. FIG. 12 shows a state in which the object detection device 300 is placed on an industrial robot RBT. The object detection device 300 includes a plurality of object detection sensor units 111, a control section 117, and a connection harness 119. Each configuration of the object detection device 300 is the same as the configuration in Example 1 (see FIGS. 1 to 4).

Second Operation of Sensor Control Program The operation of the CPU 117a based on the sensor control program in the object detection device 300 will be described below. The CPU 117a in the object detection device 300 executes an object detection process performed during normal operation of the industrial robot RBT and a sensor group information generation process performed before the normal operation of the industrial robot RBT. The object detection process performed during normal operation of the industrial robot RBT is the same as the object detection process in Example 1 (see FIG. 8), and therefore detailed description will be omitted.

1. Sensor Group Information Generation Process In the sensor group information generation process, the industrial robot RBT is caused to execute one cycle of normal operation before normal operation, and during that time, the presence or absence of interference between the object detection sensor units 113 is detected and interference is detected. Regarding the object detection sensor unit 113, sensor group information is generated so that it belongs to a different group.

2. Flowchart The object detection process based on the sensor control program executed by the CPU 117a will be described using the flowchart shown in FIG. When the CPU 117a acquires group generation start information for starting generation of sensor group information (S1301), the CPU 117a initializes the sensor group information and sets a state in which none of the object detection sensor units 111 belongs to any group (S1303).

The CPU 117a transmits operation start information to the drive device of the industrial robot RBT (S1305). Further, the CPU 117a simultaneously transmits initial detection start information indicating that object detection is to be started in the sensor group information generation process to each object detection sensor unit 113 (S1307).

The light projecting element 113a that has acquired the initial detection start information projects detection light at predetermined timing until it acquires the initial detection end information. The light receiving element 113c that has acquired the initial detection start information is placed in a light reception standby state, and the detection information is transmitted to the control unit at a predetermined timing that matches the light emission timing of the light emitting element 113a until the initial detection end information is acquired. Send to 117.

Here, when the light receiving element 113c receives a larger amount of detection light than a predetermined upper limit amount, the light receiving element 113c sends detection information indicating overflow under a predetermined lower limit, including when the detection light cannot be received. If the amount of detection light that is less than the limit is received, detection information indicating that the object could not be detected will be sent. If the amount of detection light that is within the set range from the upper limit to the lower limit is received, the object detection time will be displayed. Each is sent as detection information.

Note that the case where the light receiving element 113c receives the detection light within the set range corresponds to the case where the detection light receives reflected light that is reflected by some object. In addition, when the light receiving element 113c receives a larger amount of detection light than the upper limit amount, it directly receives the detection light emitted by the light emitting element 113a of another object detection sensor section 113 located at the opposing position. This corresponds to a case where the two object detection sensor units 113 are in an interference state.

When the CPU 117a acquires the detection information (S1309), the CPU 117a determines whether the content of the detection information is an overflow indicating an interference state or a detection time shorter than a predetermined minimum detection time (S1311). . If the content of the detection information is a detection time shorter than the predetermined minimum detection time, two object detection sensor sections 113 exist near the opposing positions, and one of the light emitting elements 113a emits light. This corresponds to a case where the light receiving element 113c of the other object detection sensor section 113 receives a part of the detected light. This is because when the light-receiving element 113c receives the reflected light of the detection light reflected by some object, it takes time to travel back and forth to the object, but the light-receiving element 113c only receives a portion of the detection light emitted by the opposing light-emitting element 113a. This is because when receiving light, only one-way time is required from one object detection sensor section 113 to the other object detection sensor section 113. Note that a case where the content of the detection information is a detection time shorter than a predetermined minimum detection time is also considered to be a case where the two object detection sensor sections 113 are in an interference state.

When determining that the content of the detection information indicates an interference state, the CPU 117a determines whether other detection information indicating an interference state is acquired at the same timing (S1313). An interference state occurs between two object detection sensor units 113 located opposite each other, so if the light receiving element 113c of one object detection sensor unit 113 is transmitting detection information indicating an interference state, the other object detection sensor unit 113 The light receiving element 113c of the object detection sensor section 113 also transmits detection information containing the interference state.

If the CPU 117a determines that detection information indicating an interference state has been acquired at the same timing, the CPU 117a selects the object detection sensor to which the object detection sensor section 113 having the light receiving element 113c that transmitted the detection information determined to be an interference state in step S1311 belongs. The unit 111 and the object detection sensor unit 111 to which the object detection sensor unit 113 having the light receiving element 113c that transmitted the detection information determined to be in an interference state in step S1313 belong to different sensor groups. 111 sensor groups are determined (S1315). Note that if the two object detection sensor units 111 already belong to different groups in the sensor group information, a new group is not determined for the two object detection sensor units 111.

If the CPU 117a determines in step S1311 that the content of the detection information is not an interference state, and if it determines in step S1313 that no other detection information indicating an interference state has been acquired, the CPU 117a moves to step S1317.

The CPU 117a repeats steps S1309 to S1315 until the industrial robot RBT completes one cycle of operation (S1317). When the industrial robot RBT completes one cycle of operation (S1317), the CPU 117a transmits initial detection completion information to each object detection sensor section 113 (S1319).

The CPU 117a determines which group all object detection sensor units 113 belong to (S1321). When the CPU 117a determines that all the object detection sensor units 113 do not belong to any group, the CPU 117a determines that all the object detection sensor units 113 do not belong to any group so that the number of object detection sensor units 113 that belong to each group existing at this stage is approximately the same. A group of object detection sensor units 113 is determined (S1323). By making the number of object detection sensor units 113 belonging to each group the same, the number of group switching is reduced, and as a result, detection can be performed at short intervals.

When the CPU 117a determines the groups related to the remaining object detection sensor units 111, and when it is determined in step S1321 that all the object detection sensor units 113 belong to any group, the CPU 117a ends the initial object detection processing.

[Other embodiments]
(1) Sensor group information: In the above-described first embodiment, the sensor group information determines the group to which each object detection sensor unit 111 belongs, but it is also possible to determine the group to which each object detection sensor unit 113 belongs. good. The same applies to Example 3.

(2) Object detection sensor unit 111: In the object detection sensor unit 111 in the first embodiment described above, the sensor arrangement flexible member 115 is used to arrange it on the industrial robot RBT having a plurality of object detection sensor sections 113. It is not limited to the illustrated example as long as the sensor section 113 can be placed therein. For example, the object detection sensor section 113 may be placed directly on the industrial robot RBT. The same applies to Examples 2 and 3.

(3) Industrial robot RBT: In the above embodiments 1 to 3, the object detection device 100 was arranged on a single industrial robot RBT, but as shown in FIG. , RBT2, the object detection device 400 may be arranged.

(4) Function of the object detection sensor unit 113: In the first embodiment described above, the object detection sensor unit 113 detects the presence of an object by detecting the distance to the object. It may also be something that detects the direction of a chisel or object.

In addition, although the object detection sensor unit 113 is configured to detect the presence of an object using a predetermined detection light, other detection waves such as infrared rays and sound waves may be used as long as the presence of an object can be detected. It's okay. The above also applies to Example 2 and Example 3.

(5) Configuration of control unit 117: In the first embodiment described above, the operation of the control unit 117 was realized using the CPU 117a, but the configuration is not limited to the example as long as it can realize the operation of the control unit 117. . For example, a dedicated logic circuit may be designed and used. The same applies to Examples 2 and 3.

(6) Connection of object detection sensor units 113: In the first embodiment described above, each object detection sensor unit 113 was connected to the control unit 117 in parallel, but each object detection sensor unit 113 is connected in cascade to each other, and The object detection sensor section 113 of the section may be connected to the control section 117.

Further, in the object detection device 100, each object detection sensor unit 111 and the control section 117 are connected by the connection harness 119, but the connection may be made wirelessly. The same applies to Examples 2 and 3.

Furthermore, in the object detection device 100, the object detection sensor section 113 and the control section 117 are connected using the connection harness 119, but a plurality of object detection sensor sections 113 are connected to one intermediate interface section, and the intermediate interface section In other words, the object detection sensor section 113 and the control section 117 may be connected to the control section 117 through an intermediate interface section. The same applies to Examples 2 and 3.

(7) Use of a light filter: In the embodiments described above, an optical filter may be further used to detect an object using only a predetermined light. The same applies to Examples 2 and 3.

(8) Sensor connection information: In the first embodiment described above, the sensor connection information is stored in the memory 117b in advance, but the sensor connection information is acquired at the stage of using the object detection device 100. It's okay. For example, when the control unit 117 is activated, the control unit 117 transmits and receives information to and from each object detection sensor unit 113 via the sensor communication circuit 113d, determines whether the object detection sensor unit 113 is connected, and determines whether the object detection sensor unit 113 is connected or not. Connection information may also be generated. Further, the connection position (eg, connection port) of the sensor communication circuit 113d may be determined. The same applies to Examples 2 and 3.

(9) Light-receiving element 113c: In the above-described first embodiment, the light-receiving element 113c uses a SPAD, but other phototransistors, photodiodes, light-receiving elements with built-in amplifier circuits, etc. can be used. Note that when using a photodiode, an amplifier circuit or a filter circuit may be arranged together with the light receiving element 113c. The same applies to Example 3.

(10) Sequential control of the object detection sensor unit 113: In the second embodiment described above, the CPU 117a transmits detection start information SS to the light emitting element 113a for each object detection sensor unit 113, and the corresponding light receiving element 113c (see FIG. 10), but as shown in FIG. 15, after selecting the sensor section to be detected (see step S1003 in FIG. 11), the light emitting element 113a belonging to the sensor section to be detected is The detection start information SS may also be transmitted.

Furthermore, as shown in FIG. 16, the detection start information SS may be transmitted to all the light projecting elements 113a before selecting the sensor unit to be detected (see step S1001 in FIG. 11). In either case, before the predetermined interval time IT has elapsed after transmitting the detection start information, the CPU 117a sequentially sends the detection information to each light receiving element 113c corresponding to the light emitting element 113a that has transmitted the detection start information. The transmission request information DS may be transmitted and the detection information may be acquired from each light receiving element 113c.

Note that the object detection sensor section 113 may have a memory that temporarily stores detection information. Further, the memory included in the object detection sensor unit 113 may be provided independently from other components, or may be provided integrally with the light receiving element 113c and the sensor communication circuit (see FIG. 3).

(11) Light-receiving element 113c: In the third embodiment described above, when the light-receiving element 113c receives an amount of detection light that is larger than the predetermined upper limit amount, it sends detection information indicating that there has been an overflow, and receives the detection light. If the amount of detection light that is less than the predetermined lower limit is received, the detection information indicating that the object could not be detected is sent within the set range from the upper limit to the lower limit. When the detection light is received, the object detection time is transmitted as detection information, but the present invention is not limited to the example as long as the detection state can be transmitted. For example, it shows the detected object detection time (including cases where it is not set or set to 0 if detection is not performed normally due to overflow, etc.) and whether or not detection was performed normally. The status (for example, in the case of overflow, an abnormality is set) may be transmitted as a set. The same applies to Example 1 and Example 2.

(12) Light-receiving element 113c: In the first embodiment described above, the light-receiving element 113c detects the distance to the object using the direct TOF (Time of Flight) method using SPAD. It is not limited to the examples as long as it can detect the distance of or the presence of an object. For example, the distance to the object may be detected using an indirect TOF method. The same applies to Example 3.

(13) Operation stop distance: In the first to third embodiments described above, the operation stop distance is set for each object detection sensor unit 113, but it may be set for each object detection sensor unit 111. . Further, all the object detection sensor units 111 may use the same operation stop distance.

The object detection device according to the present invention can be used, for example, in an industrial robot.

100 Object detection device 111 Object detection sensor unit 113 Object detection sensor section 113a Light emitting element 113b Light emitting lens 113c Light receiving element 113d Sensor communication circuit 115 Sensor arrangement flexible member 117 Control section 117a CPU
117b Memory 117g Communication circuit for sensor control 117h Communication circuit for operation control 119 Connection harness 200 Object detection device 300 Object detection device 400 Object detection device SS Detection start information RT Light reception valid period DS Detection information transmission request information

Claims (6)

An object detection device arranged along the outer peripheral surface of an industrial robot,
a detection light emitter that emits a detection light;
a reflected light receiving section that receives reflected light of the detection light, the reflected light receiving section disposed corresponding to the detection light projecting section;
a plurality of object detection sensor units having
The detection light projector projects the detection light so that the reflected light receiver does not receive the detection light projected by the detection light projectors other than the corresponding detection light projector. , and a control unit that executes a detection process to put the reflected light receiving unit in a waiting state for receiving the reflected light;
An object detection device with In the object detection device according to claim 1,
The control unit includes:
In addition to the detection light emitted by the first detection light projecting section, the reflected light receiving section corresponding to the first detection light projecting section that projects the detection light emits the second detection light. When there is a possibility that the light projecting section receives the detection light emitted, sensor group information is used that sets the first detection light projecting section and the second detection light projecting section as different groups. The detection light projector in the same group projects the detection light, and until a predetermined period of time elapses, the reflected light receiver corresponding to the detection light projector that has projected the detection light, Executing the detection process to put the reflected light in a waiting state for receiving the reflected light;
An object detection device featuring: In the object detection device according to claim 2,
The control unit includes:
controlling the detection light projecting units belonging to the same group to simultaneously project the detection light;
An object detection device featuring: In the object detection device according to claim 2 or 3,
The control unit includes:
suspending the operation of the object detection sensor unit belonging to the group different from the group when the detection process regarding the certain group is being executed;
An object detection device featuring: In the object detection device according to any one of claims 2 to 4 ,
The control unit includes:
The detection light projector and the reflected light receiver are operated for a predetermined period of time, and the detection light is emitted in addition to the detection light emitted by the first detection light projector. When the reflected light receiver corresponding to the first detection light projector receives the detection light projected by the second detection light projector, the first detection light projector and the generating sensor group information in which the second detection light projector is a different group;
An object detection device featuring: In the object detection device according to claim 1,
The control unit includes:
executing the detection process in which one of the detection light projectors projects the detection light and the corresponding reflected light receiver is placed in a standby state for receiving the reflected light until after a predetermined period of time has elapsed;
An object detection device featuring:

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