JP2008036799A - Robot system - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a robot system in which a robot highly accurately recognizes the position of itself, and a cumulative error of dead reckoning is corrected. <P>SOLUTION: In the robot system including the robot 1 and an environmental apparatus 24, the robot 1 moves in an operating environment with a moving part 21, and performs a prescribed operation in accordance with an operation command from the environmental apparatus 24 through a communication part 4. The communication parts 2, 4 are provided with an optical communication means giving and receiving information through blinking optical signals, and the robot 1 is provided with an image recognition part and corrects the position of itself in the operating environment by recognizing a lighting position of the optical signals with the image recognition part. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a robot system. More specifically, the present invention relates to a system using a robot having a function of performing infrared communication with an external device and having moving means.

  Some conventional robot systems perform communication for exchanging position information between moving bodies that move close to each other (see, for example, Patent Document 1). In addition, there has been an environment monitoring device installed in the environment that gives commands to the robot based on an infrared tag provided in the robot or the like (for example, see Patent Document 2).

As shown in FIG. 11, the robot system disclosed in Patent Document 1 is configured such that the robots 105 and 106 radiate infrared light, visible light signals, ultrasonic signals, radio frequency signals, and the like so that the distance, direction, and posture between each other. It was to get the information. Robot 106 receives a signal by the front right receiver for establishing the reception zone RZ _1. Thereby, it can be estimated that the direction of the robot 105 is a right front direction. Further, _once the signal TZ ₁ is identified and mapped to the location of the spatial area relative to the robot 105, the robot 106 can estimate the orientation of the robot 105.
As a result, both the direction of the robot 105 and the direction of the robot 105 can be estimated by the robot 106. The robot 105 emits a signal of the type described above, and the robot 106 can receive the signal and has an identification code in which information on the irradiance area of the robot 105 is encoded.

In the robot system of Patent Document 2, as shown in FIG. 12, the surrounding situation is observed by the surrounding situation observation device 216 installed in the environment, and the human observation device 218 attached to the human P2 or the like The situation from the viewpoint of a human is observed, and the situation from the viewpoint of the robot is observed by the robot body 212.
An infrared tag 214 is attached to the exhibits B1 to B4, the human observation device 218, and the like, and thereby data including identification information is acquired in each observation device. Therefore, an interaction between a person and an exhibit in such an environment is observed, and the action history of the person is sequentially recorded in the database. Then, past behavior data regarding the conversation partner is analyzed, and behaviors such as guidance and recommendation to be presented to the conversation partner are determined based on the state, and the robot main body 212 executes the behavior.

Japanese translation of PCT publication No. 2004-536715 (FIG. 1) Japanese Patent Laying-Open No. 2005-131713 (FIG. 1)

However, since the robot system of Patent Document 1 performs mapping according to the area corresponding to the reception sensitivity of the receiver and the irradiance of the transmitter, the robot system performs various operations using the robot as a toy and avoids collisions between robots. This is sufficient for the purpose, but the accuracy of the position is low and the accumulated error of dead reckoning caused by the movement cannot be corrected.
Moreover, although the robot system of patent document 2 determines the action of a robot based on an infrared signal, it could not correct the above error.
Therefore, an object of the present invention is to provide a robot system in which the robot can recognize its own position with high accuracy and correct the above error.

In order to solve the above problem, the present invention is configured as follows.
The invention according to claim 1 is a robot including a first communication unit that communicates with the outside, a moving unit, and a first control unit that controls the first communication unit and the moving unit. An environment device comprising: a second communication unit that is installed in an operating environment of the robot and that can communicate with the first communication unit; and a second control unit that controls the second communication unit; The robot is a robot system which moves the operating environment by the moving unit according to an operation command from the environmental device via the second communication unit and performs a predetermined operation. The communication unit 2 includes an optical communication unit that transmits and receives information by blinking an optical signal, and the robot includes an image recognition unit, and the image recognition unit recognizes the lighting position of the optical signal and performs the operation. Characterized by correcting its position in the environment .
According to a second aspect of the present invention, the robot includes a code table indicating correspondence between the operation command and a signal transmitted by the second communication unit in the first control unit, It is characterized by correcting its own position in the operating environment by comparison with a signal actually received by the first communication unit.
The invention described in claim 3 is characterized in that the robot has a plurality of light emitting means or light receiving means as the first communication unit and takes a logical sum of detection results by the light receiving means.
The invention described in claim 4 is characterized in that the environmental device is another robot in which the functions of the second communication unit and the second control unit are added to the robot.
According to a fifth aspect of the present invention, the first control unit recognizes the lighting of the light emitting means of the second communication unit from the image captured by the image recognition unit, and the second communication unit is normal. It is characterized by confirming that it is operating.

According to the first aspect of the present invention, since the light emitting means installed in the environment can be recognized from the image data captured by the image recognition unit, the accumulated error of dead reckoning caused by the movement can be corrected without installing a landmark separately. Can do.
According to the second aspect of the present invention, since coordinate information for self-position correction can be separated from communication data, the amount of communication data can be reduced, communication failures can be reduced, and communication delay can be reduced.
According to the third aspect of the present invention, any one of the plurality of light receiving means may be received by calculating the logical sum of the ON / OFF information of the light emitting means acquired by the plurality of light receiving means. The position and posture of the robot that can receive information from the light emitting means can be expanded.
According to the invention described in claim 4, since the robots can communicate with each other, the opportunity to perform self-position correction increases and the operation accuracy can be improved.
According to the invention described in claim 5, since the robot checks the state of the light emitting means installed in the environment by image recognition and performs error processing when no light is emitted, the communication performance can be improved.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings.

FIG. 1 is an example of the present invention, and is a schematic view showing each element constituting a system of a store where a robot 1 serves food and drink 9 to a person 8 on a seat. However, the mode of the system is not limited to this embodiment, and can be applied to all systems that control a robot using infrared rays.
In FIG. 1, reference numeral 1 denotes a robot, which includes a moving unit 21 (FIG. 2) and can move on a plane. Moreover, the arm for holding the food / beverage 9 is provided. Reference numeral 22 denotes an infrared light receiving unit connected to the communication unit 2 (FIG. 2) in the robot 1, and 3 denotes a camera for capturing an installation location of an infrared LED to be described later.
Reference numeral 4 denotes a communication unit installed on the environment side, which performs infrared communication with the communication unit 2 of the robot 1. Reference numeral 5 denotes an environment PC connected to the communication unit 4 via the network hub 6. Reference numeral 7 denotes an infrared LED which is installed in the operating environment of the robot 1 and emits light according to a command from the communication unit 4. The store system shown in FIG. 1 is configured such that an action of the person 8 or a command by a program in the environment PC 5 triggers the action of the robot 1.
For example, when the person 8 visits the store, the communication unit 4 sends an utterance such as “I welcome” by the utterance means (not shown) of the robot 1 or displays a similar message on the display unit via the infrared LED 7. Operation command data is sent to the robot 1. The infrared communication method will be described later with reference to FIG. Details of the method of detecting the visit of the person 8 or the order by the sensor are omitted. Further, depending on the contents of the above-described operation command data, the robot 1 can be made to perform a series of catering operations, for example, without being limited to speech.

FIG. 2 is a block diagram showing an outline of the robot system of the present invention. The same reference numerals as those in FIG. As shown in FIG. 2, the environmental device 24 includes a communication unit 4 and a control unit 25. Further, the communication unit 4 includes an infrared remote control transmitter 11 and an I / O conversion unit 12.
A specific example of the I / O conversion unit 12 is remote I / O. Remote I / O is to perform digital output or digital input from a host PC via a dedicated application programming interface (API) via a network such as Ethernet (registered trademark). is there.
In the present invention, the environment PC 5 corresponds to the host PC. The I / O conversion unit 12 is connected to the control unit 25 side via an Ethernet (registered trademark) cable and the network hub 6. In FIG. 2, the network hub 6 is omitted.

The control unit 25 is configured in the form of a client / server system by the environment PC 5 and other PC groups. The following software is activated on the environment PC 5. That is, a remote control transmission server 13 that outputs control information to the I / O conversion unit 12 as a digital signal, a remote control transmission client 14 that transmits operation command data to the remote control transmission server 13, and a seating detection client 15.
The voice recognition client 16 is also activated. Here, all the clients may operate in the same environment PC 5 or may operate on another PC connected via Ethernet (registered trademark) or the like. FIG. 2 shows an example in which the voice recognition client 16 is activated on a PC different from the environment PC 5.
Although detailed description of the internal operation of each client is omitted in the present invention, each client transmits operation command data to the remote control transmission server 13, and this transmission serves as a trigger for the operation of the robot 1.

  A specific example will be described taking the seating detection client 15 as an example. The seating detection client 15 monitors whether or not the seat is vacant by using a pressure sensor or the like built in each seat of FIG. Transmit to the remote control transmission server 13. In this embodiment, the operation command data is a predetermined character string. For example, the operation command data output from the seating detection client 15 when the customer sits on the right seat as viewed from the robot 1 is “Cafe_sitdown_right”. The remote control transmission server 13 has a code table as shown in Table 1 in which operation command data is associated with a channel transmitted from the infrared remote controller to the robot 1 in accordance with the operation command data.

A flow of transmission to the robot 1 will be described along the above example.
First, the remote control transmission server 13 receives operation command data “Cafe_sitdown_right” from the seating detection client 15. For this client-server communication, for example, socket communication may be used. The remote control transmission server 13 drives the relay of the I / O conversion unit 12 (remote I / O) in the communication unit 4 based on the code table of Table 1 to output to the infrared remote control transmitter 11. This output method is not limited to a relay, and may be a semiconductor switch such as an IC.
In the case of Table 1, when the remote control transmission server 13 receives the operation command data “Cafe_sitdown_right”, the relay is driven so that the channel 1 of the infrared remote controller is turned ON / OFF twice. When a relay is used, it is desirable to operate with an interval of about 150 [ms] in view of its mechanical response. When the relay is turned ON / OFF, the infrared LED 7 emits light in the same manner as when a button on the infrared remote controller is pressed. As a light emitting method of the infrared LED 7, a PWM method or the like is known. Note that the specifications and structure of the infrared remote controller may be the same as those used in general televisions.

Next, a system in the robot 1 on the receiving side will be described.
The robot 1 includes a communication unit 2, a control unit 23, a moving unit 21, and a camera 3. The communication unit 2 includes an infrared light receiving unit 22, an infrared remote control receiver 17, and an I / O conversion unit 18. The infrared light receiving unit 22 captures channel transmission to the robot 1 by the infrared LED 7. The signal received by the infrared remote control receiver 17 is sent to the control unit 23 as ON / OFF information of a digital signal via a relay or a semiconductor switch in the I / O conversion unit 18.
The control unit 23 is configured in the form of a client / server system in the same manner as the control unit 25 on the environment device 24 side. In the control unit 23, the remote control reception client 19 is activated and monitors a change in digital input from the I / O conversion unit 18 in the communication unit 2. The monitoring polling cycle is preferably about 10 [ms]. When the remote control receiving client 19 detects a channel different from the previous polling time, it sends operation command data corresponding to that channel to the command server 20. The remote control reception client 19 has the same table 1 as the remote control transmission server 13 in order to associate the channel with the operation command data.
In the command server 20, the robot 1 is moved by the moving unit 21 according to the operation command data, or the arm of the robot 1 is operated by the arm control unit (not shown).

  A feature of the present invention is that the robot 1 incorporates a camera 3 as shown in FIG. The installation location of the infrared LED 7 installed in the surrounding environment by the camera 3 can be grasped and used for the self-position identification of the robot 1. Since the light from the infrared LED 7 is outside the visible region, humans cannot visually confirm blinking. However, CCD sensors used in video cameras and digital cameras can detect a wider range of wavelengths than visible light, and infrared rays are also reflected in the captured image. The present invention has focused on this fact.

In a robot having a moving means, a technique called dead reckoning is used in which the amount of movement of the robot is estimated using a sensor such as an encoder that detects the amount of wheel rotation.
However, it is known that dead reckoning has a drawback that errors are accumulated due to slipping of wheels and the like. Therefore, conventionally, a so-called landmark such as a fluorescent tape is provided on the environment side, and a method of correcting a cumulative error of dead reckoning has been adopted.

The present invention uses the infrared LED 7 for operation command data communication installed in the surrounding environment as a landmark without installing a landmark. Since infrared wavelengths are used, the influence of ambient disturbance light such as lighting equipment can be suppressed. Further, since the infrared LED 7 may be a small one having a length of about 10 [mm] and a diameter of about 5 [mm], the installation location is not limited.
Thus, by recognizing the infrared LED installed in the surrounding environment from the image data of the camera, it is possible to correct the accumulated error of dead reckoning caused by the movement without installing the landmark.

In order to realize the above functions, when the operation command data (channel) is transmitted to the robot 1 by the infrared LED 7, the coordinate data is used to indicate where the light should be in the image captured by the camera 3. 24 in advance. Specifically, the channel corresponding to the operation command data and the coordinate data is transmitted using the code table of Table 2 in which the coordinate data is added to the code table of Table 1.
Here, in order to shorten the communication time, the robot 1 on the receiving side holds the code table of Table 2, and the environmental device 24 may perform only channel transmission corresponding to the operation command data according to Table 1. Good. In this way, the coordinate data for self-position correction can be separated from the communication data, so that the amount of communication data can be reduced, and as a result, the possibility of communication failure can be reduced and the communication delay can be reduced.

A specific method in which the robot 1 corrects its own position based on the light from the infrared LED 7 when the code table shown in Table 2 is held on the robot 1 side will be described with reference to FIGS.
FIG. 3 is a diagram showing an image obtained by capturing the light of the infrared LED 7 by the camera 3 and its coordinate system. When the robot 1 receives the operation command data from the environmental equipment side 24 by infrared communication, the data of the coordinates P (x _p , y _p ) (33 in FIG. 3) corresponding to the operation command data is obtained from the code table shown in Table 2. Pull out.
On the other hand, it is assumed that the light of the infrared LED is actually observed on the camera image 31 at the position of P _LED (x _pl , y _pl ) (32 in FIG. 3). The coordinate value of the infrared LED is obtained by performing image processing on the camera image.
The robot 1 obtains the correction amount of the self position from the difference between the coordinate value 32 and the coordinate value 33. The difference on the camera image 31 and the correction amount (Δx, Δy, Δθ) actually moved are expressed by the following equation (1). ).

The movement amounts (Δx, Δy, Δθ) in Equation (1) are as shown in FIGS. 4 (a) and 4 (b). FIG. 4A is a view of the system of the present invention as seen from the side, and FIG. 4B is a view as seen from above. The transformation matrix {C _ij } (i = 1, 2, 3, j = 1, 2) in Expression (1) is obtained by calibrating the correspondence between the robot 1 and the camera image 31 in advance.

5 and 6 are diagrams showing the configuration of the second embodiment of the present invention.
A plurality of infrared light receivers 22 on the robot 1 and infrared LEDs 7 in the surrounding environment may be provided as shown in FIG. By taking the logical sum of the light reception results of the infrared light receiving unit 22, the robot 1 can reliably receive the infrared light from the infrared LED 7. If the plurality of infrared LEDs 7 and the infrared light receiving units 22 are arranged in a distributed manner, the communication failure can be avoided as described above, and the robot 1 can reliably receive.
However, considering the cost, the robot 1 is arranged with three infrared light receiving portions 22 so that the directions of the infrared light receiving portions 22 are different from each other by 120 [°], while the infrared LED 7 is also seen from the upper surface in the surrounding environment of the robot 1. It is sufficient to arrange three so that their orientations differ by 120 [°].
FIG. 6 is a block diagram showing an outline of the robot system of FIG.
In FIG. 5, three infrared LEDs 7 are connected to the infrared remote control transmitter 11. Further, the infrared remote control receiver 17 also includes three infrared light receivers 22.

In this way, by taking the logical sum of the ON / OFF information of infrared light from multiple directions, it is sufficient if it can be received by another infrared light receiving unit even if it cannot be received by one infrared light receiving unit. The communicable position and posture of the robot 1 can be expanded.
In view of the influence of the voltage drop, the cable length between the infrared remote control transmitter 11 to the infrared LED 7 is preferably less than 3 [m]. Similarly, the cable length between the infrared remote control receiver 17 and the infrared light receiving unit 22 is preferably less than 0.3 [m] considering the influence of the voltage drop.

7 and 8 are views showing the configuration of the third embodiment of the present invention. FIG. 8 is a block diagram showing an outline of the robot 1 or 41 of FIG.
In this embodiment, as shown in FIG. 8, in addition to the infrared light receiving unit 22, the robot 1 provided with the infrared LED 7 and the infrared remote control transmitter 11 and the other robot 41 having the same configuration, one robot The self-position correction is performed on the basis of one robot by capturing the light emitted from the infrared LED 7 with the other camera 3. In this case, it is desirable to determine which robot has a smaller cumulative movement amount after performing self-position correction with respect to the environment, and use the robot with the smaller cumulative movement amount as a reference. In order to determine which robot is used as a reference, each robot may record the accumulated movement amount, and the magnitude may be compared between a predetermined threshold and the accumulated movement amount. You may compare mutual movement amount.
As self-position correction data, not only the relative distance between the robots but also the absolute coordinate values may be stored in the above code table. In that case, when any of the robots performs self-position correction with respect to the environment, the robot moves after holding the absolute coordinate value corresponding to the location. The absolute coordinate value held by the robot with the shorter movement distance after self-position correction is added to the movement amount and stored in the code table, and the reference absolute coordinate value is sent to the referring robot. .

FIG. 9 is a flowchart showing a processing procedure in the third embodiment of the present invention. Steps S801 to S806 show the steps of the flow.
Here, in order to avoid collision with each other, the robots regularly emit the infrared LED 7 so as to inform the surroundings of the presence of each other. First, the robot 1 corrects its own position with respect to the surrounding environment (step S801). Next, when the robot 1 moves to approach another robot 41 and captures the light emission of each infrared LED 7 (step S802), the subsequent processing branches depending on the movement distance l from the position where the self-position correction is first performed. (Step S803).
That is, if the movement distance l is equal to or greater than the predetermined threshold value l _h (No in step S803), the robot 1 does not communicate with the robot 41 using the infrared LED (step S805).
If the movement distance l is less than the predetermined threshold l _h , the robot 1 causes the robot 41 to emit an infrared LED, the robot 41 captures the light with the camera, and self-positions based on the position of the light on the camera image. Is corrected (S806). Here, both l and l _h are positive real numbers.

If the movement distances of the robot 1 and the robot 41 are both greater than or equal to the predetermined threshold value l _h or less than l _h , the movement distance of the robot 1 and the robot 41 is exchanged by the infrared LED 7 and is shorter than the movement distance of the opponent To be the standard.

If the conversion matrix between the relative distance / attitude between the robots and the position of the counterpart infrared LED on the camera image is D, immediately after the robot 1 corrects its own position, the matrix C in equation (1) is replaced with D. The following formula holds.
The elements of the matrix D are determined as follows. The position of the infrared LED of the robot 1 in the camera image of the robot 41 when the robot 1 faces the robot 41 at a position where the robot 1 corrects its position relative to the environment is obtained by calibration as in the matrix C. The robot 1 transmits its corrected movement amount {Δx, Δy, Δθ} ^T to the robot 41. When the robot 41 receives the movement amount {Δx, Δy, Δθ} ^T from the robot 1, the robot 41 translates the position on the image of the LED observed from the equation (2) by {Δx _p , Δy _p } ^T. . The difference between the translated position of the original LED and the point to be referred to by the robot 41 is reflected in the matrix D, the amount of movement of the robot 41 is obtained, and the position is corrected.

As described above, the robots communicate with each other to increase the chances of self-position correction, thereby improving the operation accuracy.

  Further, as a fourth embodiment of the present invention, when the robot 1 performs self-position correction, it is confirmed by the camera 3 whether or not the environment-side infrared LED 7 emits light. It may be determined that a failure has occurred, or reset processing and re-communication processing of the I / O conversion unit 12 in the environmental device 24 may be performed.

FIG. 10 is a flowchart showing a processing procedure in the fourth embodiment of the present invention. Steps S901 to S909 indicate the steps of the flow.
As shown in FIG. 10, first, a variable n for storing an integer of 0 or more is set to 0 (step S901). Here, n acquires an image by the camera 3 (step S902), and determines whether the infrared LED 7 emits light (step S903). If light emission from the infrared LED 7 can be confirmed (Yes in step S903), the process proceeds to self-position correction processing. If light emission cannot be confirmed (No in step S903), the variable n is incremented (step S904) and compared with a predetermined number N (N: natural number) (step S905).
If the number of failures is less than N times, an utterance such as “cannot confirm that the infrared LED is turned on” is performed by the utterance means (not shown) of the robot 1 or a similar message is displayed on the display unit (step S906). .
If the number of failures reaches N times (No in step S905), the robot 1 speaks (not shown) using the utterance means (not shown) such as “infrared LED is broken” or similar message on the display Is displayed (step S909). The number of failure determinations N is preferably about 3. If the number of failures is less than N times, a retransmission request is further sent to the environmental device 24 (step S907).
In order to make a retransmission request, an infrared LED 7 is provided in the robot as shown in FIG. 7, and an infrared light receiving unit is further provided on the environment device side, and communication is performed by infrared rays as described above. Alternatively, the communication is performed by detecting the utterance of the retransmission request of the robot by the voice recognition means (not shown) on the environmental device side. When receiving the retransmission request, the environmental device 24 retransmits the operation command data to the robot 1 after resetting the I / O conversion unit 12 (step S908). After the retransmission, the process returns to the image acquisition process by the camera 3 again (step S902).
As described above, since the state of the infrared LED 7 on the environment side is confirmed and error processing is performed when light is not emitted, communication performance can be improved.

  The robot system of the present invention can be widely applied to robot systems that can communicate by means such as infrared rays.

Schematic diagram showing a first embodiment of the robot system of the present invention Block diagram of the robot system of FIG. The figure which shows the image which caught infrared LED with the camera which is installed in the robot The figure explaining the self-position correction of the robot based on the camera image of FIG. Schematic diagram showing a second embodiment of the robot system of the present invention Block diagram of the robot system of FIG. The figure which shows the 3rd Example of this invention Block diagram of the robot system of FIG. The flowchart which shows the process sequence of 3rd Example of this invention. The flowchart which shows the process sequence of the 4th Example of this invention. Diagram showing the outline of a conventional robot system Diagram showing the outline of a conventional robot system

Explanation of symbols

1 Robot 2 Communication unit 3 Camera 4 Communication unit 5 Environmental PC
6 Network hub 7 Infrared LED
8 people 9 food and drink 11 infrared remote control transmitter 12 I / O conversion unit 13 remote control transmission server 14 remote control transmission client 15 seating detection client 16 voice recognition client 17 infrared remote control receiver 18 I / O conversion unit 19 remote control reception client 20 command server 21 Moving unit 22 Infrared light receiving unit 23 Control unit 24 Environmental device 25 Control unit 31 Camera image 32 Observed infrared LED light coordinates 32 Original infrared LED light coordinates 41 Other robots 105 and 106 Robot 212 Robot 214 Infrared tag 216 Ambient condition observation device 218 Human observation device 220 Stuffed animal observation device

Claims (5)

A robot including a first communication unit that communicates with the outside, a moving unit, and a first control unit that controls the first communication unit and the moving unit;
An environment device including a second communication unit that is installed in an operating environment of the robot and that can communicate with the first communication unit; and a second control unit that controls the second communication unit. ,
The robot is a robot system that moves the operating environment by the moving unit according to an operation command from the environmental device via the second communication unit and performs a predetermined operation,
The first and second communication units include optical communication means for transmitting and receiving information by blinking an optical signal,
The robot system includes an image recognition unit, and corrects its own position in the operation environment by recognizing a lighting position of the optical signal by the image recognition unit.   The robot includes a code table indicating correspondence between the operation command and a signal transmitted from the second communication unit in the first control unit, and the contents of the code table and the first communication unit are actually in the first communication unit. The robot system according to claim 1, wherein the position of the robot in the operating environment is corrected by comparison with the received signal.   The robot system according to claim 1, wherein the robot has a plurality of light emitting means or light receiving means as the first communication unit, and takes a logical sum of detection results by the light receiving means.   The robot system according to claim 1, wherein the environmental device is another robot in which the functions of the second communication unit and the second control unit are added to the robot.   The first control unit recognizes the lighting of the light emitting means of the second communication unit from the image captured by the image recognition unit, and confirms that the second communication unit is operating normally. The robot system according to claim 1.