JP2007240455A - Contact detector, and contact detection method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a contact detector and a contact detection method, capable of detecting the propriety in contact of a fingertip 20 with a plate 30, without attaching a sensor for detecting the contact of the fingertip 20 with the plate 30, onto the fingertip 20. <P>SOLUTION: A tapping counter 1 is the contact detector for detecting the contact of the fingertip 20 with the plate 30, and is provided with a photographing part 11 for photographing the fingertip 20 and the plate 30, a distance measuring part 13 for measuring the first time-serial variation of a distance from the fingertip 20 to the plate 30, based on positions of the fingertip 20 and the plate 30 within an image photographed by the photographing part 11, a high-pass filter 14 for extracting a time-serial variation of a cut-off frequency or more of frequency component as the second time-serial variation, out of the first time-serial variation measured by the distance measuring part 13, and a contact detecting part 15 for detecting the contact of the fingertip 20 with the plate 30, when the second time-serial variation extracted by the high-pass filter 14 comes to a threshold value or more. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a contact detection device and a contact detection method for detecting contact between an object and a contact target object.

In recent years, the diversification of human interfaces in information devices has progressed, and various parts of the human body are used as interfaces. In particular, active research is being conducted using a finger that can be operated at high speed and high speed according to the human intention as an interface. For example, Non-Patent Document 1 describes an apparatus in which a sensor for detecting acceleration is attached to a fingertip. As shown in Non-Patent Document 1, when the sensor is directly attached to the fingertip, there is an advantage that desired information on the fingertip can be easily measured.
Koji Tsukada, Michiaki Yasumura, Ubi-Finger, Research on Mobile Oriented Gesture Input Devices, Information Processing Society of Japan, Vol 43, No. 12, pp. 3675-3684, 2002

  However, in the method in which the sensor is directly attached to the object to be detected, there is a problem in that, for example, a sensor with a large scale may hinder the operation of the object to be detected. Furthermore, when the object to be detected is, for example, a part of the human body, there is a problem in that the human being feels uncomfortable when the sensor is attached to the body.

  Therefore, the present invention provides a technique capable of detecting desired information for an object to be detected without attaching a sensor to the object to be detected. Specifically, the present invention provides a contact detection device capable of detecting whether or not a contact between an object and a contact target object can be detected without mounting a sensor that detects that the object is in contact with the contact target object. It is another object of the present invention to provide a contact detection method.

  As a result of intensive studies, the present inventors have temporarily increased the high-frequency component in the time-series change amount with respect to the distance from the object to the contact target object at the moment when the object and the contact target object contact each other. It was found to occur. Furthermore, it has been found that the magnitude of the generated high frequency component is proportional to the collision force at the moment when the object comes into contact with the contact target object. The present invention has been made based on these new findings.

  That is, a contact detection device according to the present invention is a contact detection device that detects contact between an object and a contact target object, and includes an imaging unit that images the object and the contact target object, and an object in an image captured by the imaging unit. And a first time series measured by the distance measuring means, a distance measuring means for measuring a first time series change amount that is a time series change amount of the distance from the object to the contact target object based on the position of the contact target object. Among the change amounts, a high-pass filter that extracts a time-series change amount of a frequency component that is equal to or higher than a predetermined cutoff frequency as a second time-series change amount, and a second time-series change amount that the high-pass filter extracts are predetermined. It is characterized by comprising contact detection means for detecting contact between the object and the contact target object when the threshold value is exceeded.

  Further, the contact detection method according to the present invention is a contact detection method for detecting a contact between an object and a contact target object, wherein the imaging unit captures the object and the contact target object, and the distance measurement unit includes: A distance measuring step for measuring a first time-series change amount that is a time-series change amount of the distance from the object to the contact target object based on the positions of the object and the contact target object in the image captured in the shooting step; A high-pass filtering step in which the high-pass filter extracts, as a second time-series change amount, a time-series change amount of a frequency component equal to or higher than a predetermined cutoff frequency in the first time-series change amount measured by the distance measuring unit; When the second time-series change amount extracted in the high-pass filtering step is greater than or equal to a predetermined threshold, the contact detection means makes contact between the object and the contact target object. It is characterized in that it comprises a contact detection step of detecting that.

  According to the contact detection device and the contact detection method of the present invention, the distance measuring unit measures the first time-series change amount of the distance from the object to the contact target object. Next, the high-pass filter removes low frequency components below a predetermined cutoff frequency from the first time series change amount, and extracts a second time series change amount that is a set of high frequency components in the first time series change amount. . Here, what the present inventors have found, that is, at the moment when the object and the contact target object come into contact, the high-frequency component temporarily changes in the time-series change amount with respect to the distance from the object to the contact target object. Focus on what happens. That is, when the second time-series change amount of only the high frequency component becomes equal to or greater than a predetermined threshold, the contact detection means detects that there is a contact between the object and the contact target object. Can do.

  Thus, in the contact detection device and the contact detection method of the present invention, for example, a contact detection sensor is not attached to the object for the purpose of detecting contact between the object and the contact target object. Therefore, according to the present invention, it is possible to detect contact between an object and a contact target object, and it is possible to prevent a contact detection sensor attached to the object from hindering the operation of the object.

  The contact detection device further includes a collision force measurement unit that measures a value proportional to the second time-series change amount extracted by the high-pass filter as a value representing a collision force when the object and the contact target object contact each other. It is characterized by that.

  Further, the contact detection method uses a value proportional to the second time-series change amount extracted by the high-pass filtering step as a value representing the collision force when the object and the contact target object are in contact with each other. It further comprises a collision force measurement step for measuring.

  Here, what the present inventors have found, that is, the magnitude of the generated high frequency component in the time-series change amount with respect to the distance from the object to the contact target object, the object and the contact target object are in contact with each other. Focus on being proportional to the momentary impact force. That is, the collision force measuring means can detect a predetermined value proportional to the second time-series change amount as a collision force generated when the object and the contact target object come into contact with each other.

  Further, in the contact detection device, an object to be imaged by the imaging means is provided with an arbitrary sign for indicating the position of the object, the imaging means images the sign, and the distance measuring means is imaged by the imaging means. A first time series change amount that is a time series change amount of the distance from the sign to the contact target object is measured based on the position of the sign in the captured image.

  In the contact detection method, an object to be imaged in the imaging step is provided with an arbitrary sign for representing the position of the object, and the imaging unit in the imaging step images the sign and measures the distance in the distance measuring step. The means measures a first time series change amount that is a time series change amount of the distance from the sign to the contact target object based on the position of the sign taken in the photographing step in the photographed image. To do.

  In this case, a sign that is smaller and lighter than the object can be used as the sign indicating the position of the object. For this reason, for example, by recognizing the position of the sign instead of recognizing the position of the object from the photographed image, the amount of calculation required in the image recognition is reduced and the position of the object is directly recognized from the photographed image. Equivalent results can be obtained.

  In the contact detection device, the predetermined cutoff frequency in the high-pass filter is 40 hertz. In the contact detection method, the predetermined cutoff frequency in the high-pass filtering step is 40 hertz.

  In this way, by setting the cut-off frequency to 40 hertz, it is possible to detect contact extremely efficiently, particularly when the object is a portion corresponding to a human finger or a human finger in a robot. That is, a high frequency component generated when a human finger or a part corresponding to a human finger in a robot comes into contact with a contact target object clearly appears in the second time series change amount. It is possible to reliably detect whether or not the corresponding part of the finger or the robot is in contact with the contact target object.

  In the contact detection device, the predetermined threshold value in the contact detection means is 0.5 mm. In the contact detection method, the predetermined threshold value in the contact detection step is 0.5 mm.

  In this way, by setting the threshold value to 0.5 mm, it is possible to detect contact extremely efficiently, particularly when the object is a part corresponding to a human finger or a human finger in a robot. That is, the contact detection means can ignore a minute high frequency component that can be generated when the corresponding part of the human finger or the robot is not in contact with the contact target object, and the corresponding part of the human finger or the robot. It is possible to reliably detect whether or not contact with the contact target object is possible.

  ADVANTAGE OF THE INVENTION According to this invention, even if it does not equip the said object with the sensor which detects that an object contacts a contact target object, it becomes possible to detect the contact possibility of an object and a contact target object.

  The knowledge of the present invention can be easily understood by considering the following detailed description with reference to the accompanying drawings shown for illustration only. Subsequently, embodiments of the present invention will be described with reference to the accompanying drawings. If possible, the same parts are denoted by the same reference numerals, and redundant description is omitted.

[First embodiment]
A tapping counter 1 will be described as a first embodiment of a contact detection device and a contact detection method according to the present invention. The tapping counter 1 counts the number of times the fingertip 20 has tapped the surface of the plate 30 without attaching a contact detection sensor or the like to the fingertip 20. First, the configuration of the tapping counter 1 will be described with reference to FIGS. 1 to 3 show a fingertip (object) 20 as a contact detection target, a plate (contact target object) 30 as a contact target of the fingertip 20, and an imaging unit (imaging means) 11 and a control unit as a contact detection device. 12 is a diagram for explaining a configuration of a tapping counter 1 including 12.

  As shown in FIGS. 1 and 2, a marker (marker) 21 for indicating the position of the fingertip 20 is provided on the fingertip 20 that is a target of contact detection in the first embodiment. The marker 21 is smaller and lighter than a finger and has a higher recognition rate in image recognition. In the first embodiment, for example, a light ball with a diameter of 5 mm is used. As will be described later, the tapping counter 1 recognizes the position of the marker 21 instead of directly recognizing the position of the fingertip 20 from the captured image.

  As shown in FIGS. 1 and 3, the plate 30 in the first embodiment is an object to be touched by the fingertip 20 and is basically a flat plate made of iron having a thickness of 2.9 mm, assuming that it does not move. is there. For this reason, the board 30 becomes the background in the captured image, and for example, it is not necessary for the tapping counter 1 to recognize up to the board 30 for each captured frame. That is, in the first embodiment, the coordinates of a predetermined part in the captured image are used as the position information of the plate 30.

  The imaging unit 11 shown in FIGS. 1 and 3 extracts position information (position coordinates) of the marker 21 in an image obtained by imaging the marker 21 and the plate 30 in real time. In the first embodiment, for example, It is a normal high-speed vision camera having a CMOS image sensor with a spatial resolution of 1280 × 1024 pixels. The photographing unit 11 outputs the extracted position information of the marker 21 to the control unit 12.

  The control unit 12 shown in FIG. 1 detects contact between the fingertip 20 and the plate 30 based on the position information of the marker 21 and the plate 30. In the first embodiment, the control unit 12 is a computer system that includes a CPU, a memory, a communication interface, a storage unit such as a hard disk, a display unit such as a monitor, and the like as physical components.

  The positional relationship among the fingertip 20, the board 30, and the imaging unit 11 will be described in detail with reference to FIG. As shown in FIG. 3, in the first embodiment, it is assumed that the fingertip 20 moves on a plane about 400 mm forward as viewed from the photographing unit 11. The imaging unit 11 is disposed so as to keep the optical axis horizontal with respect to the plate 30 and 80 mm above the surface of the plate 30. The field of view of the imaging unit 11 is set to 288 mm × 230 mm near the fingertip 20 position, and is set as a spatial resolution of 0.225 mm per pixel. As described above, the position of the fingertip 20 can be calculated by tracking the marker 21 attached to the fingertip 20 by the imaging unit 11 and using a conventional image recognition technique. In the first embodiment, the imaging unit 11 obtains the position of the fingertip 20 by tracking the marker 21 of the fingertip 20 using, for example, a 64 × 64 pixel window and calculating the position of the center of gravity. The measurement rate at the position of the fingertip 20 is preferably changed according to the number of target fingers, for example, 900 [fps] for one finger, and 470 [fps] for two, three, and four fingers, respectively. 390 [fps] and 280 [fps] are desirable. In the first embodiment, in order to simplify the description, the number of target fingers is one and the measurement rate of the fingertip 20 position is 900 [fps]. As described above, the position of the plate 30 is set to the coordinates of a predetermined part in the captured image.

  Returning to FIG. 1, the control unit 12 of the tapping counter 1 includes a distance measurement unit (distance measurement unit) 13, a high-pass filter 14, and a contact detection unit (contact detection unit) 15. Hereafter, each component which comprises the control part 12 is demonstrated in detail, referring further FIGS.

  The distance measurement unit 13 obtains the distance from the fingertip 20 to the plate 30 based on the position information of the plate 30 and the position information of the marker 21 input from the photographing unit 11, and the time-series change amount of the distance. The first time series change amount is measured. 4-7 is a figure which shows the 1st time series variation | change_quantity of the distance which the distance measurement part 13 measured. 4-7, the height of the marker 21 which makes the height of the upper surface of the board 30 0 mm (reference height) is expressed as the distance.

  FIG. 4 shows the first time-series change amount for one second when the fingertip 20 repeats the tapping operation without contact between the fingertip 20 and the plate 30. FIG. 5 is an enlarged view of FIG. 4 on the time axis, and shows the first time-series change amount in 0.2 seconds when there is no contact between the fingertip 20 and the board 30. As can be seen from FIGS. 4 and 5, when there is no contact between the fingertip 20 and the plate 30, the first time-series change amount does not include a high frequency component and appears as a smooth curve.

  FIG. 6 shows the first time-series change amount in one second when the tapping operation is repeated while the fingertip 20 is in contact with the plate 30. FIG. 7 is an enlarged view of FIG. 6 on the time axis, and shows a first time-series change amount in 0.2 seconds when there is a contact between the fingertip 20 and the board 30. As can be seen from FIGS. 6 and 7, when there is a contact between the fingertip 20 and the plate 30, a temporary distortion occurs in the vicinity of a height of 10 mm corresponding to the thickness of the finger. Thereby, it can be seen that a high frequency component is generated in the first time-series change amount at the moment when the fingertip 20 contacts the plate 30. The distance measuring unit 13 outputs the first time-series change amount as shown in FIGS. 4 to 7 to the high-pass filter 14.

  The high-pass filter 14 removes a low-frequency component less than a predetermined cutoff frequency from the first time-series change amount input from the distance measurement unit 13, and changes the frequency component above the cutoff frequency in time series. The amount is extracted as the second time-series change amount. That is, the second time series change amount extracted by the high-pass filter 14 is a set of high frequency components equal to or higher than the cutoff frequency extracted from the first time series change amount. In the first embodiment, the cutoff frequency is 40 hertz.

  FIG. 8 shows the result of the high-pass filter 14 filtering the first time-series variation shown in FIGS. 4 and 5, that is, the second time-series variation when there is no contact between the fingertip 20 and the board 30. FIG. Since the high frequency component is not generated in the first time series change amount shown in FIGS. 4 and 5, the high frequency component hardly appears in the second time series change amount shown in FIG. 8.

  9 shows the result of filtering by the high-pass filter 14 with respect to the first time series change amount shown in FIGS. 6 and 7, that is, the second time series change amount when the fingertip 20 and the board 30 are in contact with each other. FIG. In accordance with the time when the high frequency component (distortion) is generated in the first time series change amount shown in FIGS. 6 and 7, a high frequency component is also generated greatly in the second time series change amount shown in FIG. The high pass filter 14 outputs the second time-series change amount as shown in FIGS.

  The contact detection unit 15 detects contact between the fingertip 20 and the plate 30 by comparing the second time-series change amount input from the high-pass filter 14 with a predetermined threshold value. Specifically, the contact detection unit 15 detects that the fingertip 20 and the plate 30 are in contact when the second time series change amount is equal to or greater than a predetermined threshold, and the second time series change amount is When it is less than the predetermined threshold, it is detected that there is no contact between the fingertip 20 and the plate 30. In the first embodiment, the predetermined threshold is 0.5 mm, and is indicated by a dotted line in FIGS.

  In FIG. 8, since the second time-series change amount does not have a threshold value of 0.5 mm or more, the contact detection unit 15 does not detect contact between the fingertip 20 and the plate 30. On the other hand, in FIG. 9, the second time-series change amount exceeds the threshold value seven times in one second, and the contact detection unit 15 detects that the contact between the fingertip 20 and the plate 30 has occurred seven times. .

  Next, the operation (contact detection method) of the tapping counter 1 of the first embodiment will be described with reference to FIGS. FIG. 10 is a flowchart showing the operation of the tapping counter 1. FIG. 11 is a diagram for explaining the result of the operation performed by the tapping counter 1 when the fingertip 20 performs the tapping operation 9 times in 2 seconds. FIG. 12 shows the result of the operation performed by the tapping counter 1 when the fingertip 20 performs two tapping operations and four feint operations (empty swinging operation in which the fingertip 20 and the plate 30 do not contact) in two seconds. It is a figure for demonstrating.

  First, the imaging unit 11 extracts position information of the marker 21 in an image obtained by imaging the marker 21 and the plate 30 in real time. The imaging unit 11 outputs the extracted position information of the marker 21 to the distance measurement unit 13 (imaging step, step S1 in FIG. 10).

  Next, the distance measurement unit 13 obtains the distance from the fingertip 20 to the plate 30 based on the position information of the plate 30 and the position information of the marker 21 input from the imaging unit 11, and calculates the distance in time series. The first time-series change amount that is a large change amount is measured. (A) of FIG. 11 and (a) of FIG. 12 show the first time-series change amount measured by the distance measuring unit 13. The distance measurement unit 13 outputs the measured first time series change amount to the high pass filter 14 (distance measurement step, step S2 in FIG. 10).

  Next, the high-pass filter 14 removes a low-frequency component having a cutoff frequency of less than 40 Hz from the first time-series change amount input from the distance measuring unit 13, and removes a frequency component having the cutoff frequency of 40 Hz or more. A time-series change amount is extracted as a second time-series change amount. FIG. 11B and FIG. 12B show the second time-series change amount extracted by the high-pass filter 14. The high pass filter 14 outputs the extracted second time-series change amount to the contact detection unit 15 (filtering step, step S3 in FIG. 10).

  Next, the contact detection unit 15 detects the contact between the fingertip 20 and the plate 30 by comparing the second time-series change amount input from the high-pass filter 14 with a threshold value of 0.5 mm. Specifically, the contact detection unit 15 detects that the fingertip 20 and the plate 30 are in contact when the second time series change amount is equal to or greater than the threshold value of 0.5 mm, and the second time series change amount is detected. When the threshold is less than 0.5 mm, it is detected that there is no contact between the fingertip 20 and the plate 30 (contact detection step, step S4 in FIG. 10).

  FIG. 11 (c) shows that when the fingertip 20 performs nine tapping operations in 2 seconds, the contact detection unit 15 counts based on the second time-series change amount shown in FIG. 11 (b). Indicates the number of times The contact detection unit 15 counts contact at the moment when the second time-series change amount exceeds the threshold value of 0.5 mm, and counts 9 times in 2 seconds. This result coincides with the number of times the fingertip 20 actually touches the plate 30, and it can be said that the tapping counter 1 accurately counted the contact between the fingertip 20 and the plate 30.

  On the other hand, FIG. 12C shows the second time-series change amount shown in FIG. 12B when the fingertip 20 performs two tapping operations and four feint operations in 2 seconds. And the number of times the contact detection unit 15 has counted. The contact detection unit 15 counts the contact at the moment when the second time-series change amount exceeds the threshold value of 0.5 mm, and performs the count twice in 2 seconds in accordance with the moment of contact. This result coincides with the number of times and time when the fingertip 20 actually touches the board 30, and the tapping counter 1 accurately counts the contact between the fingertip 20 and the board 30 even when the fingertip 20 is performing a faint operation. It can be said that.

  Then, the effect | action and effect of 1st Embodiment are demonstrated. According to the tapping counter 1 of the first embodiment, even if a contact detection sensor is not attached to the fingertip 20 for the purpose of detecting contact between the fingertip 20 and the plate 30, for example, FIG. As shown, contact between the fingertip 20 and the plate 30 can be accurately detected. For this reason, it can prevent that the contact detection sensor with which the fingertip 20 was mounted | worn interferes with the operation | movement of the said fingertip 20, for example. Furthermore, for example, it is possible to prevent a contact detection sensor attached to a finger from interfering with the movement of the finger and causing a human to feel uncomfortable.

  In addition, as the marker 21 in the first embodiment, a marker that is smaller and lighter than the fingertip 20 is used as a marker that represents the position of the fingertip 20. For this reason, for example, by recognizing the position of the sign instead of recognizing the position of the fingertip 20 from the photographed image, the position of the fingertip 20 is directly recognized from the photographed image while reducing the amount of calculation required for image recognition. You can get the same results.

  Further, in the tapping counter 1 of the first embodiment, by setting the cut-off frequency to 40 hertz, the high frequency component generated when the fingertip 20 and the plate 30 are in contact with each other in the second time series change amount. It appears clearly. For this reason, the contact detection unit 15 can reliably detect whether or not the fingertip 20 and the plate 30 are in contact with each other.

  Further, in the tapping counter 1 of the first embodiment, by setting the threshold value to 0.5 mm, fine high frequency components that can be generated when the fingertip 20 and the plate 30 are not in contact are ignored. be able to. For this reason, the contact detection unit 15 can reliably detect whether or not the fingertip 20 and the plate 30 are in contact with each other.

  The preferred first embodiment of the present invention has been described above, but it goes without saying that the present invention is not limited to the first embodiment.

  For example, in the first embodiment, a human finger is an object to be contact-detected. However, the present invention is not limited to this, and a portion corresponding to a human finger in a robot is to be a contact-detection target. It may be an object. Even in this case, for example, a contact detection sensor is not attached to the part for the purpose of detecting contact between the part corresponding to the human finger in the robot and the plate 30. For this reason, it can prevent that the contact detection sensor with which the said part was mounted | worn, for example, gives trouble to the operation | movement of the said part.

  Furthermore, in the first embodiment, the non-moving plate 30 is basically an object that is a contact target of the fingertip 20, but any moving object may be an object that is a contact target of the fingertip 20. In this case, the imaging unit 11 extracts the positional information in the captured image of the object that is the contact target of the fingertip 20 in real time and outputs it to the distance measuring unit 13. Then, the distance measurement unit 13 obtains the distance from the fingertip 20 to the contact target object based on the position information of the contact target object and the marker 21 input from the imaging unit 11.

[Second Embodiment]
A collision force measurement device 2 will be described as a second embodiment of the contact detection device and the contact detection method according to the present invention. The collision force measuring device 2 includes all the elements constituting the tapping counter 1 in the first embodiment, and each component is arranged in an equivalent positional relationship (see FIG. 3), and further, a collision force measurement unit (impact force measurement unit) Means) 16. The collision force measuring device 2 is a device that measures not only the possibility of contact between the fingertip 20 and the plate 30 but also the collision force at the moment when the fingertip 20 and the plate 30 contact each other. First, the configuration of the collision force measuring device 2 will be described with reference to FIGS.

  FIG. 13 is a schematic configuration diagram of the collision force measuring device 2. As shown in FIG. 13, the collision force measurement device 2 includes an imaging unit 11 and a control unit 12, and the control unit 12 includes a distance measurement unit 13, a high-pass filter 14, a contact detection unit 15, and a collision force measurement unit 16. The high pass filter 14 outputs the extracted second time series change amount to the collision force measurement unit 16. The collision force measurement unit 16 measures a value proportional to the peak value of the second time-series change amount input from the high-pass filter 14 as a value representing the collision force when the fingertip 20 and the plate 30 are in contact with each other. is there.

  The collision force measured by the collision force measurement unit 16 is used for, for example, a virtual musical instrument including the collision force measurement device 2. In this case, the virtual musical instrument or the like can appropriately determine the volume or sound generation time of the sound source generated by the virtual musical instrument based on the collision force measured by the collision force measurement unit 16. Furthermore, the virtual musical instrument or the like can appropriately determine the time for generating the sound source based on the contact time detected by the contact detection unit 15.

  The operation of the collision force measuring device 2 of the second embodiment will be described with reference to FIGS. FIG. 14 is a flowchart showing the operation of the collision force measuring device 2. FIG. 15 shows an operation performed by the collision force measuring device 2 when the fingertip 20 performs a tapping operation twice and a feint motion four times (an empty motion in which the fingertip 20 and the plate 30 do not contact) in 2 seconds. It is a figure for demonstrating the result of.

  First, the imaging unit 11 extracts position information of the marker 21 in an image obtained by imaging the marker 21 and the plate 30 in real time. The imaging unit 11 outputs the extracted position information of the marker 21 to the distance measurement unit 13 (imaging step, step S1 in FIG. 14).

  Next, the distance measurement unit 13 obtains the distance from the fingertip 20 to the plate 30 based on the position information of the plate 30 and the position information of the marker 21 input from the imaging unit 11, and calculates the distance in time series. The first time-series change amount that is a large change amount is measured. FIG. 15A shows the first time-series change amount measured by the distance measuring unit 13. The distance measuring unit 13 outputs the measured first time series change amount to the high-pass filter 14 (distance measuring step, step S2 in FIG. 14).

  Next, the high-pass filter 14 removes a low-frequency component having a cutoff frequency of less than 40 Hz from the first time-series change amount input from the distance measuring unit 13, and removes a frequency component having the cutoff frequency of 40 Hz or more. A time-series change amount is extracted as a second time-series change amount. FIG. 15B shows the second time-series change amount extracted by the high-pass filter 14. The high-pass filter 14 outputs the extracted second time-series change amount to the contact detection unit 15 and the collision force measurement unit 16 (filtering step, step S3 in FIG. 14).

  Next, the contact detection unit 15 detects the contact between the fingertip 20 and the plate 30 by comparing the second time-series change amount input from the high-pass filter 14 with a threshold value of 0.5 mm. Specifically, the contact detection unit 15 detects that the fingertip 20 and the plate 30 are in contact when the second time series change amount is equal to or greater than the threshold value of 0.5 mm, and the second time series change amount is detected. When the threshold value is less than 0.5 mm, it is detected that there is no contact between the fingertip 20 and the plate 30 (contact detection step, step S4 in FIG. 14).

  (C) of FIG. 15 is based on the second time series change amount shown in (b) of FIG. 15 when the fingertip 20 performs two tapping operations and four feint operations in 2 seconds. The number of times counted by the contact detection unit 15 is shown. The contact detection unit 15 counts the contact at the moment when the second time-series change amount exceeds the threshold value of 0.5 mm, and performs the count twice in 2 seconds in accordance with the moment of contact. This result coincides with the number of times and time when the fingertip 20 actually contacts the plate 30, and it can be said that the collision force measuring device 2 accurately counted the contact between the fingertip 20 and the plate 30.

  Next, the collision force measurement unit 16 measures a value proportional to the peak value of the second time-series change amount input from the high-pass filter 14 as a value representing the collision force when the fingertip 20 and the plate 30 are in contact with each other. (Collision force measurement step, step S5 in FIG. 14).

  (D) of FIG. 15 is based on the second time-series change amount shown in (b) of FIG. 15 when the fingertip 20 performs two tapping operations and four feint operations in 2 seconds. The collision force measured by the collision force measurement unit 16 is shown. Referring to FIG. 15B, the peak value of the high frequency component generated at about 3.3 seconds is about 4 mm, and the peak value of the high frequency component generated at about 4.7 seconds is about 3 mm. It is. In FIG. 15D, the collision force measured at a time of about 3.3 seconds is 8N, and the collision force measured at a time of about 4.7 seconds is 6N. From this result, it can be seen that the collision force measurement unit 16 measures the collision force in proportion to the peak value of the generated high frequency component.

  Then, the effect | action and effect of 2nd Embodiment are demonstrated. According to the collision force measuring device 2 of the second embodiment, for example, without installing a collision force measurement sensor on the fingertip 20 for the purpose of measuring the collision force at the time of contact between the fingertip 20 and the plate 30, As shown in FIG. 15, the collision force at the time of contact between the fingertip 20 and the board 30 can be detected. For this reason, for example, it is possible to prevent the collision force measurement sensor attached to the fingertip 20 from hindering the operation of the fingertip 20. Furthermore, for example, it is possible to prevent a collision force measurement sensor attached to a finger from interfering with the movement of the finger and causing a human to feel uncomfortable.

  The preferred second embodiment of the present invention has been described above, but it goes without saying that the present invention is not limited to the second embodiment.

  For example, in the second embodiment, a human finger is an object that is a target of collision force measurement at the time of contact. However, the present invention is not limited to this. It is good also as an object used as the object of the collision force measurement. Even in this case, for example, a collision force measurement sensor is not attached to the part for the purpose of measuring the collision force at the time of contact between the part corresponding to the human finger and the plate 30 in the robot. For this reason, it can prevent that the collision force measurement sensor with which the said part was mounted | worn, for example, gives trouble to the operation | movement of the said part.

  Furthermore, the collision force measuring device 2 in the second embodiment is not limited to a virtual musical instrument, and can be appropriately applied to a mouse of a personal computer, for example.

1 is a schematic configuration diagram of a tapping counter 1 according to a first embodiment of the present invention. It is a figure for demonstrating the marker 21 provided in the fingertip 20. FIG. It is a figure for demonstrating the positional relationship of the fingertip 20, the board 30, and the imaging | photography part 11. FIG. It is a figure which shows the 1st time series variation | change_quantity of the distance between the fingertip 20 and the board 30. FIG. FIG. 5 is an enlarged view of FIG. 4 along the time axis. It is a figure which shows the 1st time series variation | change_quantity of the distance between the fingertip 20 and the board 30. FIG. It is the figure which expanded FIG. 6 on the time axis. It is a figure which shows the 2nd time series variation | change_quantity of the distance between the fingertip 20 and the board 30. FIG. It is a figure which shows the 2nd time series variation | change_quantity of the distance between the fingertip 20 and the board 30. FIG. 4 is a flowchart showing the operation of the tapping counter 1. It is a figure which shows the result of the operation | movement which the tapping counter 1 performed. It is a figure which shows the result of the operation | movement which the tapping counter 1 performed. It is a structure schematic diagram of the collision force measuring apparatus 2 which concerns on 2nd Embodiment of this invention. 3 is a flowchart showing the operation of the collision force measuring device 2. It is a figure which shows the result of the operation | movement which the collision force measuring apparatus 2 performed.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 ... Tapping counter, 2 ... Collision force measuring device, 20 ... Finger tip, 21 ... Marker, 30 ... Board, 11 ... Imaging | photography part, 12 ... Control part, 13 ... Distance measuring part, 14 ... High pass filter, 15 ... Contact detection part , 16 ... collision force measuring unit.

Claims (10)

A contact detection device for detecting contact between an object and a contact target object,
Imaging means for imaging the object and the contact target object;
A distance for measuring a first time-series change amount, which is a time-series change amount of the distance from the object to the contact target object, based on the positions of the object and the contact target object in the image captured by the photographing unit. Measuring means;
A high-pass filter for extracting, as the second time-series change amount, a time-series change amount of a frequency component equal to or higher than a predetermined cutoff frequency in the first time-series change amount measured by the distance measuring unit;
Contact detection means for detecting contact between the object and the contact target object when the second time-series change amount extracted by the high-pass filter exceeds a predetermined threshold value. Contact detection device.   The apparatus further comprises a collision force measurement unit that measures a value proportional to the second time-series change amount extracted by the high-pass filter as a value representing a collision force when the object and the contact target object are in contact with each other. The contact detection device according to claim 1. The object to be imaged by the imaging means is provided with an arbitrary sign for representing the position of the object,
The photographing means photographs the sign,
The distance measuring unit measures a first time series change amount that is a time series change amount of a distance from the sign to the contact target object based on a position of the sign taken by the photographing means in a photographed image. The contact detection device according to claim 1, wherein the contact detection device is a contact detection device.   The contact detection apparatus according to claim 1, wherein the predetermined cutoff frequency in the high-pass filter is 40 hertz.   The contact detection apparatus according to claim 1, wherein the predetermined threshold value in the contact detection unit is 0.5 mm. A contact detection method for detecting contact between an object and a contact target object,
An imaging step in which the imaging means images the object and the contact target object;
The distance measurement means is a first time that is a time-series change amount of the distance from the object to the contact target object based on the positions of the object and the contact target object in the image captured in the capturing step. A distance measurement step for measuring a series change amount;
A high-pass filtering step in which a high-pass filter extracts, as a second time-series change amount, a time-series change amount of a frequency component equal to or higher than a predetermined cut-off frequency in the first time-series change amount measured by the distance measuring unit. When,
A contact detection step in which contact detection means detects contact between the object and the contact target object when the second time-series change amount extracted in the high-pass filtering step exceeds a predetermined threshold value. A contact detection method comprising:   Collision in which a collision force measuring unit measures a value proportional to the second time-series change amount extracted in the high-pass filtering step as a value representing a collision force when the object and the contact target object are in contact with each other. The contact detection method according to claim 6, further comprising a force measurement step. The object to be imaged in the imaging step is provided with an arbitrary sign for representing the position of the object,
The photographing means in the photographing step photographs the sign,
The distance measuring means in the distance measuring step is a time-series change amount of the distance from the marker to the contact target object based on the position of the marker captured in the imaging step in the captured image. The contact detection method according to claim 6, wherein a time series change amount is measured.   The contact detection method according to claim 6, wherein the predetermined cutoff frequency in the high-pass filtering step is 40 Hz. The contact detection method according to claim 6, wherein the predetermined threshold value in the contact detection step is 0.5 mm.

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