JP2007268620A - Tactile sensor device for robot - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a tactile sensor device for a robot, detecting even if contact is weak, and fitting a sensor to a cover of the robot. <P>SOLUTION: This tactile sensor device for a robot includes: an actuator 4 for vibrating the cover 50 covering the periphery of the body of the robot 40; the sensor 5 for detecting the vibration of the cover fitted to the cover; a vibration control part 3 for controlling the actuator to vibrate under a fixed condition; and a contact detecting part 2 for comparing the vibration applied by the actuator with the vibration detected by the sensor to detect the presence/absence of contact with the cover. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a tactile sensor device for a robot that is attached to a cover of a moving or operating robot and detects contact, collision, pressing, or slipping with a person or an object.

  Conventionally, as a contact sensor for a robot, a sensor in which a large number of switch-like sensors are arranged on the surface of the robot cover, a sensor such as a tactile sensor mounted in a certain range in a matrix, and a cover for a soft hollow space of the robot. It is known that a pressure sensor is attached to each of the hollow spaces, and the pressure is detected by fluctuations in the pressure. In addition, there is a type in which the cover is a hard cover and vibration sound when the cover is hit is detected by a microphone. On the other hand, there are known devices that attach several sensors to a plate and detect it when the plate is struck. In addition, when touched with a touch panel, there is also one that detects a contact by feeding back the contact by vibrating the panel.

  In Patent Document 1, as a skin covering the whole body of a communication robot, a laminate of urethane and silicon rubber layers is used, and a plurality of piezo sensor sheets are dispersed and arranged in the skin, thereby detecting contact and ensuring safety and affinity. A high-performance communication robot is disclosed.

  Patent Document 2 discloses a communication robot that functions as a proximity sensor or a pressure sensor by dynamically changing the sensitivity of a piezoelectric sensor in the communication robot.

  Patent Document 3 discloses a tactile sensor in which a piezoelectric element and a vibrator that oscillates at a constant frequency are integrally joined with a laminated structure via an insulating member to simultaneously detect both pressure and slip. .

  In Patent Document 4, a vibrator and a contact are vibrated in a resonance state by a self-excited oscillation circuit using a feedback loop, and information on change in the resonance state when the contact is in contact with an object is obtained. A tactile sensor as information is disclosed.

  In Patent Literature 5, when a button displayed on a screen is pressed by a user with an input device on a panel such as a touch panel in which a touch sensor is superimposed on a display, the user is caused to vibrate by vibrating the panel. A switch for recognizing that the button has been pressed is disclosed.

Further, Non-Patent Document 1 discloses that in the robot's interpersonal behavior, a “biological character” is produced by always vibrating the entire body of the robot in the vertical and horizontal directions using a servo motor.
JP 2004-283975 A JP 2005-161450 A JP 2002-31574 A Japanese Patent Laid-Open No. 10-62328 JP 2005-228161 A “Direction of affinity by robot's interpersonal behavior” Satoshi Nakata, Tomomasa Sato, Taketoshi Mori, Hiroshi Mizoguchi, Journal of the Robotics Society of Japan, Vol.15, No.7, pp.1068-1074, 1997

  As for the above problems, the use of the switch, the tactile sensor, and the hollow space all require a space for installation, and the restrictions on the cover are large. In addition, it is possible to discriminate contact with large changes such as tapping and stroking with a microphone, but it is difficult to discriminate touching and touching.

  In addition, it is difficult to install a flexible skin sensor in the whole body shown in Patent Documents 1 and 2 because the restrictions on the cover are large. In addition, the pressure can be measured, but the slip is difficult to measure.

  The tactile sensor shown in Patent Document 3 can detect a pressure sensation and a slip sensation by applying vibration to the sensor and detecting its suppression. However, because of its configuration, application to a cover that covers the entire robot is not possible. It's not easy.

  The tactile sensor disclosed in Patent Document 4 similarly detects suppression, but is intended to measure the hardness of an object and does not detect contact with a robot cover.

  The switch shown in Patent Document 5 feeds back the result of contact with the flat plate to the user and is not suitable for a robot cover.

  In the robot shown in Non-Patent Document 1, whether or not a person has touched is detected by two touch sensors, and the vibration operation performed in advance does not detect contact.

  The present invention has been made in consideration of the above circumstances, and an object of the present invention is to provide a robot tactile sensor device that can detect even a weak contact and can attach a sensor to a robot cover. And

  A robot tactile sensor device according to an aspect of the present invention includes an actuator that vibrates a cover that covers the periphery of a robot body, a sensor that is attached to the cover and detects vibration of the cover, and vibrates the actuator under certain conditions. A vibration control unit that performs control so as to perform a detection, and a contact detection unit that compares the vibration provided by the actuator with the vibration detected by the sensor to detect the presence or absence of contact with the cover. And

  A plurality of sensors may be attached to the cover.

  The actuator may be an actuator that can apply vibration and whose output changes when vibration is suppressed.

  The actuator may be an actuator provided to the robot for operating the robot.

  A detector for detecting whether or not there is a person around the robot is further provided, and the vibration control unit controls the actuator only when the detector detects that a person is around the robot. Then, the cover may be vibrated.

  The vibration control unit may vibrate the cover via the actuator only when the robot is moving or operating.

  In addition, when a contact is detected by the contact detection unit, the vibration control unit may perform control so that a vibration different from the vibration before the contact is detected is applied to the cover.

  The vibration control unit may apply vibration to the cover in accordance with a unique rhythm of a person or an animal.

  According to the present invention, it is possible to detect even a weak contact, and to attach the sensor to the cover of the robot.

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

(First embodiment)
A configuration of a tactile sensor device for a robot according to a first embodiment of the present invention is shown in FIG. The sensor device 1 of this embodiment includes a contact detection unit 2, a vibration control unit 3, an actuator 4, a sensor 5, and a detection signal processing unit 6.

  The actuator 4 is composed of, for example, a vibration motor or a piezoelectric element, and is attached to the cover 50 of the robot as shown in FIG. When a motor or a piezoelectric element is used as the actuator, it is possible to sense the contact from the output when a person or object comes into contact with the cover 50 and vibration is suppressed. Further, in order to vibrate the cover 50, vibration may be applied by oscillating a servo motor used for the movement of the robot or the operation of the arm or the like. In this case, there is an effect that it is not necessary to provide a dedicated actuator for oscillating by diverting a servo motor for movement of the robot or an arm.

  The robot cover 50 is divided into a plurality of parts covering the periphery of the robot, and each part itself is made of a hard member that easily vibrates and is fixed to the robot body via a flexible member that is difficult to transmit vibration.

  As shown in FIG. 2, the sensor 5 is attached to the cover 50 of the robot, and includes, for example, an acceleration sensor, a piezoelectric sensor, a microphone that can detect the vibration of the cover, and the like, and detects the vibration of the cover 50. The sensor 5 may detect vibration using a signal that can be acquired by the actuator 4 when vibration is suppressed, for example, by measuring an output current of a vibration motor used as the actuator 4.

  The vibration control unit 3 controls the actuator 4 based on the command waveform from the contact detection unit 2 so that the robot cover 50 vibrates at a constant cycle. The vibration control unit 3 may apply vibration only when the robot is moving or when an arm or the like is physically moving. In addition, a sensor that detects a person around the robot (for example, a pyroelectric sensor or a camera that detects the movement of the person by detecting a temperature change around the robot using infrared rays) is attached to the robot. The vibration may be applied only when it is detected that a person is present. It is effective in reducing energy loss by vibrating only when a robot that touches or is likely to touch a person or an object moves or moves, or when there is a person around.

  The detection signal processing unit 6 converts the vibration detected by the sensor 5 into a waveform of an electric signal (for example, a voltage signal), and sends the converted detection waveform to the contact detection unit 2.

  The contact detection unit 2 compares the command waveform given to the vibration control unit 3 with the detection waveform sent from the detection signal processing unit 6 to detect the presence / absence of contact, collision, pressure, and slip. As an example of a specific detection method, a reference vibration waveform in the cover 50 is given in advance, and a waveform in a state where the cover 50 is not in contact is measured. This is a reference detection waveform. Next, in the same manner, while giving a reference vibration waveform, a detection waveform when a part of the cover 50 is touched with a certain force is acquired, and the reference vibration detection waveform is accumulated. When actually measuring, the contact location is estimated by comparing the reference vibration detection waveform with the detection waveform of the detection signal processing unit 6. Similarly, a waveform in which the pressure is changed, a waveform when a collision is applied, and a waveform when a slip is applied are accumulated and compared with these to detect a contact state. As another detection method, there is a method in which the vibration characteristics of the cover 50 are obtained in advance, and the contact state and position are detected by dynamic analysis. The contact detection unit 2 can also increase the detection sensitivity by changing the vibration applied to the control vibration unit 3 when the waveform is small when contact is detected. In addition, changing the vibration makes it possible to feed back to the person that the contact has been detected when the contact target is a person. For example, in the case of a person, when the robot is touched so that it will be jerky when the arm is touched (the arm vibrates slightly), by changing the vibration pattern or amplitude, , It has the effect of informing the person of the detection. FIG. 3 shows a schematic diagram of signals detected when the cover 50 is vibrated and the robot comes into contact with a person or an object. As can be seen from FIG. 3, when the robot is in contact with a person or an object while vibration is applied to the cover 50, the amplitude of the vibration waveform of the cover 50 is reduced or the period of vibration is disturbed.

  FIG. 4 schematically shows a state when the robot 40 to which the tactile sensor device 1 of the present embodiment is attached contacts the person 60, and FIG. 5 schematically shows a state when the robot 40 contacts the object 70. As shown in FIG. 4 or 5, the robot 50 contacts the person 60 or the object 70 in a state where the cover 50 vibrates, and detects the contact state / contact portion.

  Next, the period of vibration given to the cover 50 of the robot by the tactile sensor device of this embodiment will be described. This period of vibration causes vibration at a high frequency to detect whether or not there is a strict contact. However, if the frequency is too high, the sound generated by the vibration itself becomes unpleasant. Therefore, it is possible to use a waveform in an ultrasonic region that does not bother the person so as not to be uncomfortable. In addition, a vibration pattern with a large period of several Hz, which expresses the heartbeat of a living thing, and a fine vibration that a small animal such as a squirrel is performing even when stationary, gives a more biological character. It is known to have an effect of giving an intimate feeling to the user by performing the performance (for example, see Non-Patent Document 1 described above). Also in this embodiment, there is an effect that the robot gives an intimate feeling to the user by vibrating the vibration cycle in accordance with the inherent rhythm of the person or animal.

  As described above, according to the present embodiment, since vibration is generated in the robot cover and contact with the cover is detected based on the vibration waveform, weak contact can also be detected. In addition, it is possible to produce a “lifelike” effect, that is, to produce a feeling that the robot is “living”, and it is possible to eliminate the “uncomfortable feeling due to lack of movement” that is a problem with the robot. . In addition, when a person touches the robot, feedback of the touch can be provided.

(Second Embodiment)
Next, the configuration of a tactile sensor device for a robot according to a second embodiment of the present invention is shown in FIG. In the tactile sensor device 1A of the present embodiment, in the tactile sensor device 1 of the first embodiment shown in FIG. 1, the sensor 5 is replaced with a plurality of sensors 5A, and the detection signal processing unit 6 is replaced with a plurality of detection signal processing units 6A. It has a configuration. The detection signal processing unit 6A is provided corresponding to the plurality of sensors 5A. In this embodiment, an example of attachment of the actuator and the plurality of sensors 5A attached to the robot cover 50 is shown in FIG. In the present embodiment, a plurality of sensors 5 </ b> A and detection signal processing units 6 </ b> A are arranged to increase the detection waveform, and the accuracy of the contact position and the contact state estimated by the contact detection unit 2 can be improved.

  As described above, similarly to the first embodiment, this embodiment also generates vibration on the robot cover and detects contact with the cover based on the waveform of the vibration. Therefore, weak contact is also detected. be able to. In addition, it is possible to produce a “lifelike” effect, that is, to produce a feeling that the robot is “living”, and it is possible to eliminate the “uncomfortable feeling due to lack of movement” that is a problem with the robot. . In addition, when a person touches the robot, feedback of the touch can be provided.

The block diagram which shows the structure of the tactile sensor apparatus for robots by 1st Embodiment of this invention. The schematic diagram which shows the cover with which the actuator and sensor which concern on the tactile sensor apparatus for robots of 1st Embodiment were attached. The signal waveform diagram which shows the presence or absence of the contact detected by the tactile sensor apparatus for robots of 1st or 2nd embodiment. The schematic diagram which shows a mode when the robot which attached the tactile sensor apparatus for robots of 1st or 2nd embodiment contacted the person. The schematic diagram which shows a mode when the robot which attached the tactile sensor apparatus for robots of 1st or 2nd embodiment contacted the object. The block diagram which shows the structure of the tactile sensor apparatus for robots by 2nd Embodiment of this invention. The schematic diagram which shows the cover with which the actuator and sensor which concern on the tactile sensor apparatus for robots of 2nd Embodiment were attached.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Robot tactile sensor apparatus 1A Robot tactile sensor apparatus 2 Contact detection part 3 Vibration control part 4 Actuator 5 Sensor 5A Sensor 6 Detection signal processing part 6A Detection signal processing part 40 Robot 50 Cover 70 Object

Claims (8)

An actuator that vibrates a cover that covers the periphery of the robot body;
A sensor attached to the cover for detecting the vibration of the cover;
A vibration control unit that controls the actuator to vibrate under certain conditions;
A contact detector that compares the vibration applied by the actuator with the vibration detected by the sensor to detect the presence or absence of contact with the cover;
A tactile sensor device for a robot, comprising:   A tactile sensor device for a robot, wherein a plurality of the sensors are attached to the cover.   3. The robot tactile sensor device according to claim 1, wherein the actuator is an actuator that can apply vibration and whose output changes when the vibration is suppressed. 4.   3. The robot tactile sensor device according to claim 1, wherein the actuator is an actuator provided to the robot to operate the robot. 4.   A detector for detecting whether or not there is a person around the robot, and the vibration control unit controls the actuator only when the detector detects that there is a person around the robot. The robot tactile sensor device according to any one of claims 1 to 4, wherein the cover is vibrated.   The robot tactile sensor device according to claim 1, wherein the vibration control unit vibrates the cover via the actuator only when the robot is moving or operating. .   7. The control according to claim 1, wherein when the contact is detected by the contact detection unit, the vibration control unit performs control so as to give the cover a vibration different from the vibration before the contact is detected. The robot tactile sensor device according to any one of the above.   The robotic tactile sensor device according to claim 1, wherein the vibration control unit applies vibration to the cover in accordance with a unique rhythm of a person or an animal.

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