Haptic transmission device and haptic transmission method

Abstract

The present invention: analyzes, for each fingertip of an operator or a robot, scattering characteristics centered on forward scattering and rearward scattering of a spatial distribution of that fingertip; detects, on the basis of a change in the scattering characteristics, a deformation state of the pad of each fingertip; and stores, as haptic data in a storage unit, a distribution state and a transition state of pressing force applied to the pad of each fingertip.

Description

Haptic sense transmission device and haptic sense transmission method

[0001] The present invention relates to a haptic sense transmission device and a haptic sense transmission method, and is suitable for use in teaching, for example, fine fingertip movements such as those used in laboratory experiments to patients with paralysis of the fingers or robots.

[0002] Traditionally, laboratories at universities and research institutions often require researchers to perform repetitive, detailed manual tasks, such as injecting minute amounts of reagents into test tubes or placing minute objects in precise positions.

[0003] Because the detailed manual work in these laboratories is complex and varied depending on the research topic, it is practically very difficult to replace it with robots, as is the case with mass-produced industrial manufacturing.

[0004] For example, a robot that handles an object (core) has been proposed that has a tactile sensor that detects the force acting from the object on a gripping mechanism (multi-fingered, multi-jointed hand), and in an autonomous operation mode, controls the gripping mechanism to grip the object by referring to pre-created teaching data and signals acquired from the tactile sensor, while in a heteronomous operation mode, controls the gripping mechanism by referring to signals acquired from a state detection device that detects the state of the instructor's hand, and creates teaching data by referring to signals acquired from the tactile sensor (see Patent Document 1).

[0005] In addition, a method has been proposed for impedance-controlling a robot arm so that it moves in the direction of the operating force acting on it, using direct teaching, in which an instructor grasps a specific part of the robot and manually operates the robot arm (see Patent Document 2).

[0006] In other words, during direct instruction, a series of motion data is acquired one by one when the instructor operates the robot arm, and after acquiring a series of time series data, instruction data is generated based on this data.In automatic operation, in which the robot arm is regenerated according to the instruction data, the reproducibility of the robot arm's motion as instructed by the instructor is improved.

[0007] JP 2023-128047 A JP 2019-136860 A

[0008] The robot in Patent Document 1 is a system for automating the core placement process, one of the various processes involved in casting, and uses electrical resistance, capacitance, piezoelectric, or optical tactile sensors attached to the surface of each finger of the gripping mechanism.

[0009] For this reason, while typical tactile sensors can achieve the delicacy and accuracy required to place a fragile core into a fragile mold, it is extremely difficult to detect minute levels of tactile sensation, such as changes in pressure or friction on the pads of a human fingertip.

[0010] Furthermore, in the method of controlling a robot arm by direct teaching in Patent Document 2, the robot arm is controlled in a desired manner based on the movement of the robot arm at the time of teaching, but since this is limited to the movement level of the robot arm itself, it is extremely difficult to reproduce the same fingertip movement down to a minute level for the hand attached to the robot arm.

[0011] From a similar perspective, when an instructor teaches fingertip movements to a paralyzed patient whose fingertips are insensitive due to paralysis or other reasons, it is extremely difficult to get the paralyzed patient to reproduce the same fingertip movements as the instructor down to the finest detail.

[0012] The present invention has been made in consideration of the above points, and proposes a tactile sensation transmission device and a tactile sensation transmission method that can reproduce, down to a minute level, the same fingertip movements made by an operator or robot on the target of transmission.

[0013] In order to solve such problems, the present invention provides a light source unit that is attached to or held on the back or side of each fingertip of an operator or robot and that irradiates the back or side with continuous light; a light detection unit that detects scattered light obtained as a result of the continuous light propagating inside each fingertip of the operator or robot; a scattering characteristic analysis unit that analyzes the scattering characteristics of the spatial distribution within each fingertip, mainly forward scattering and backward scattering, for each fingertip based on the detection signal output from the light detection unit; and a scattering characteristic analysis unit that analyzes the scattering characteristics of each fingertip analyzed by the scattering characteristic analysis unit and that analyzes the scattering characteristics obtained when each fingertip is in a non-contact state. an abdominal deformation detection unit that detects the deformation state of the abdomen of each fingertip based on changes in scattering characteristics analyzed by the scattering characteristic analysis unit, using the default value for each fingertip read from the storage unit as a reference; and a pressure estimation unit that estimates the distribution and transition states of the pressure of each fingertip on the abdomen based on the deformation state of the abdomen of each fingertip detected by the abdominal deformation detection unit, and the control unit stores the distribution and transition states of the pressure of each fingertip on the abdomen estimated by the pressure estimation unit in the storage unit as tactile data for each fingertip.

[0014] As a result, the tactile sensation transmission device stores tactile sensation data for each fingertip of the operator or robot, and by reading it out from the memory unit as needed, it can be applied to, for example, a patient with paralyzed fingers or another robot, and the same tactile sensation can be reproduced for the paralyzed patient or robot down to a fine level (for example, the feeling of the fingers twisting).

[0015] Furthermore, in the present invention, when the pad of each finger is set as an elastic membrane that can be depressed toward the back side when pressed from the front side, the abdominal deformation detection unit detects the deformation state of the pad of each fingertip by detecting the contact area when pressed from the front side of the elastic membrane, as well as the degree and direction of depression at the contact area.

[0016] As a result, the tactile sensation transmission device detects the deformation state of the pads of each of the operator's or robot's fingertips as the degree and direction of depression of the contact area when pressed from the surface side, making it possible to obtain tactile sensation data with relatively high accuracy even when the pads of each fingertip make not only surface contact but also point contact.

[0017] Furthermore, in the present invention, the light detection unit has a plurality of light receiving elements arranged on the back and / or sides of each fingertip, and the scattered light detection results of each of the light receiving elements are synchronously combined to generate a detection signal.

[0018] As a result, in the tactile sensation transmission device, the scattered light obtained by shining it inside each fingertip of the operator or robot is received and detected at multiple points on each fingertip, which allows the scattering characteristics to have depth, making it possible to obtain tactile sensation data with relatively high accuracy.

[0019] Furthermore, in the present invention, the light source unit is composed of a light-emitting element that emits coherent light as continuous light, and the scattering characteristic analysis unit includes, as the scattering characteristic, phase information obtained from the detection signal output from the light detection unit.

[0020] As a result, in the tactile sensation transmission device, the continuous light irradiated onto the inside of each fingertip of the operator or robot is made coherent, so that phase information can be obtained from the scattered light in the light detection unit.Since light is received and detected at multiple points on each fingertip, the scattering characteristics can be given depth, making it possible to obtain tactile sensation data with relatively high accuracy.

[0021] Furthermore, in the present invention, a pressure sensor is provided that detects the pressure corresponding to the deformation of one or both of the left and right sides of each fingertip of the operator or robot, and the abdominal deformation detection unit detects the deformation state of the abdominal part of each fingertip based on the change in scattering characteristics analyzed by the scattering characteristic analysis unit and the change in pressure detected by the pressure sensor.

[0022] As a result, the tactile sensation transmission device is able to detect the deformation state of the pad of each fingertip of the operator or robot not only from the back of each fingertip but also from the left and right side portions in a complementary manner, thereby making it possible to significantly improve the accuracy of the tactile sensation data related to each fingertip.

[0023] Furthermore, in the present invention, the control unit calibrates default values ​​representing the scattering characteristics obtained from the scattering characteristic analysis unit when each fingertip is in a non-contact state, based on the pressure detected by the pressure sensor when the fingertip is in a non-contact state.

[0024] As a result, the tactile sensation transmission device calibrates the error of the detection method based on optical techniques for the deformation state of the pad of each fingertip of an operator or robot at the back of each fingertip with a detection method based on physical techniques for the side of each fingertip, thereby making it possible to significantly improve the accuracy of the tactile sensation data for each fingertip.

[0025] Furthermore, the present invention further includes a sensory transmission unit that is attached to or held at a desired location on the operator's upper limb and transmits physical sensations to the skin surface of the desired location, and the sensory transmission unit transmits the distribution and transition of the pressure applied to the abdomen of each of the operator's fingertips as feedback to the skin surface of the desired location based on the tactile data sent by the control unit.

[0026] As a result, the tactile sensation transmission device transmits the distribution and transition of the pressure applied to the abdomen of each of the operator's fingertips as feedback to the skin surface of the desired part of the operator's upper limb as a physical sensation, so that in cases where the sensation in each fingertip is insensitive due to paralysis, such as in patients with paralysis of the fingers, the operator can indirectly feel the tactile sensation through another part of the body that is sensitive to the sensation.

[0027] Furthermore, the present invention includes a first step of irradiating a back or side of each fingertip of an operator or robot with continuous light and detecting scattered light obtained as a result of the continuous light propagating inside each fingertip as a detection signal; a second step of analyzing, for each fingertip, scattering characteristics, mainly forward scattering and backward scattering, of the spatial distribution within each fingertip based on the detection signal detected in the first step; a third step of storing, in a memory unit, the scattering characteristics obtained when each fingertip is in a non-contact state, for the scattering characteristics of each fingertip analyzed in the second step; a fourth step of detecting a deformation state of the pad of each fingertip based on changes in the scattering characteristics analyzed by the scattering characteristic analysis unit, using the default value for each fingertip read from the memory unit as a reference; a fifth step of estimating a distribution state and transition state of pressure force on the pad of each fingertip based on the deformation state of the pad of each fingertip detected in the fourth step; and a sixth step of storing, in a memory unit, the distribution state and transition state of pressure force on the pad of each fingertip estimated in the fifth step.

[0028] As a result, the tactile sensation transmission method stores tactile sensation data for each fingertip of the operator or robot, and by reading it out from the memory unit as needed, it can be applied to, for example, a patient with paralyzed fingers or another robot, and the same tactile sensation can be reproduced for the paralyzed patient or robot down to a fine level (for example, the feeling of the fingers twisting).

[0029] According to the present invention, it is possible to realize a tactile sense transmission device and a tactile sense transmission method that can reproduce the tactile sense of each fingertip of an operator or robot on a transmission target at a minute level.

[0030] Fig. 2 is a conceptual diagram explaining a haptic sense transmission device according to a first embodiment. Fig. 3 is a conceptual diagram explaining an optical unit shown in Fig. 1. Fig. 4 is a conceptual diagram showing the functional configuration of a control unit shown in Fig. 1. Fig. 5 is a conceptual diagram explaining a pressing trial device. Fig. 6 is a conceptual diagram explaining a haptic sense transmission device according to a second embodiment. Fig. 7 is a conceptual diagram explaining a haptic sense transmission device according to a third embodiment.

[0031] An embodiment of the present invention will be described in detail below with reference to the drawings.

[0032] 1 shows a haptic sense transmission device 1 according to a first embodiment, which has optical units 2 attached or held corresponding to the fingertips of an operator, and a control unit 3 that individually and collectively controls each of the optical units 2. In this first embodiment, an optical unit 2 is attached to each of the operator's three fingertips, namely, the thumb, index finger, and middle finger, and each of these optical units 2 is electrically connected to the control unit 3 via a cable 4.

[0033] The optical unit 2 is attached to the back of the operator's fingertips and includes a light source unit 10 that irradiates the back with continuous light, and a light detection unit 11 that detects scattered light obtained as a result of the continuous light propagating inside each of the operator's fingertips (FIG. 2(A)).

[0034] The light source unit 10 is composed of a semiconductor laser (light emitting element) that emits near-infrared laser light with a wavelength of about 700 to 900 nm as continuous light, which is relatively highly transmissive to living organisms.

[0035] The light detection unit 11 has a plurality of light receiving elements 12 arranged in a predetermined array pattern on the back of each fingertip (FIG. 2(B)). These light receiving elements 12 are composed of photodiodes or phototransistors with sensitivity characteristics corresponding to the wavelength of the continuous light emitted from the light source unit 10. The light detection unit 11 synchronously combines the detection results of the scattered light from each light receiving element 12 and generates a detection signal.

[0036] 3, the control unit 3 has a general control unit 20 that controls the entire device, and a storage unit 21 that reads and writes various data under the control of the general control unit 20. The general control unit 20 is mainly configured with a microcomputer that is made up of an MCM (Multi-Chip Module) equipped with a CPU (Central Processing Unit), memory, etc.

[0037] The general control unit 20 has the control functions of a scattering property analysis unit 30, an abdominal deformation detection unit 31, and a pressure estimation unit 32 in addition to controlling the entire device.

[0038] The scattering property analysis unit 30 analyzes the scattering properties of each fingertip, focusing on forward scattering and backward scattering of the spatial distribution within the fingertip, based on the detection signal output from the light detection unit 11. These scattering properties are expressed by the scattering phenomenon of light occurring in the internal space of each fingertip, i.e., the scattering intensity, which is proportional to the volume of the scattering region that interacts with the light intensity of continuous light incident on the internal space of each fingertip and inversely proportional to the square of the distance to the detection point, and a probability distribution of directionality according to the proportion of forward scattering and backward scattering.

[0039] The central control unit 20 stores, in the storage unit 21, the scattering characteristics obtained when each fingertip is in a non-contact state as default values ​​for the scattering characteristics of each fingertip analyzed by the scattering characteristic analysis unit 30.

[0040] The abdominal deformation detection unit 31 detects the deformation state of the abdominal part of each fingertip based on the change in scattering characteristics analyzed by the scattering characteristic analysis unit 30, using the default value for each fingertip read from the storage unit 21 as a reference.

[0041] Specifically, when the abdomen of each finger is set as an elastic membrane that can be depressed toward the back side when pressed from the front side, the abdomen deformation detection unit 31 detects the deformation state of the abdomen of each fingertip by detecting the contact area when pressed from the front side of the elastic membrane, as well as the degree and direction of depression at the contact area.

[0042] The pressure estimation unit 32 estimates the distribution and transition of pressure of each fingertip on the abdomen based on the deformation state of the abdomen of each fingertip detected by the abdomen deformation detection unit 31.

[0043] In fact, the correspondence between the deformation state of the pad of each fingertip and the distribution and transition state of the pressure force on the pad of each fingertip is determined in advance as a value specific to the operator, while applying pressure in all directions and at multiple levels to each fingertip.

[0044] Specifically, while the operator wears a tactile sensation transmission device on each fingertip, a pressure trial device 40 (Figure 4) is applied, which applies point and area pressure to the pads of each fingertip in all directions and with multiple levels of pressure.

[0045] 4, the pressure trial device 40 has a fingertip holder 41 that holds the fingertip of an operator wearing the tactile sense transmission device 1 so that the pad of the fingertip is in a non-contact state, and a pressure force applying unit 42 that projects a point-like or planar probe (not shown) at the tip to press against the contact target. Note that the point-like probe and the planar probe are set to be selectively switchable.

[0046] The pressure applying unit 42 sets a fine mesh-like measurement pattern on the surface of the pad of the fingertip held by the fingertip holding unit 41, and applies pressure to the contact surface by protruding a probe based on the measurement pattern.

[0047] In this case, the pressure applying unit 42 sequentially positions the tip of the probe as the contact point in mesh units that form the measurement pattern, changes the protrusion angle of the tip of the probe, and also changes the degree of pressure, thereby adjusting the direction and degree of depression at the contact point.

[0048] In this way, the general control unit 20 can estimate the distribution and transition states of the pressure force of each fingertip on the abdomen based on the deformation state of the abdomen of each fingertip actually detected by the abdomen deformation detection unit 31, while referring to values ​​specific to the operator obtained using the pressure trial device 40 (the correspondence between the deformation state of the abdomen of each fingertip and the distribution and transition states of the pressure force of each fingertip on the abdomen).

[0049] The central control unit 20 stores the distribution and transition of the pressure on the pad of each fingertip estimated by the pressure estimating unit 32 in the storage unit as haptic data for each fingertip.

[0050] As a result, the tactile sensation transmission device 1 stores tactile sensation data relating to each of the operator's fingertips and reads it out from the memory unit 21 as needed, making it possible to apply it to, for example, a patient with paralyzed fingers or a robot, and to reproduce the same tactile sensation down to a fine level (for example, the feeling of the fingers twisting) for the paralyzed patient or robot.

[0051] (2) Configuration of the tactile sense transmission device according to the second embodiment In Figure 5, in which parts corresponding to those in Figure 1 are given the same symbols, the tactile sense transmission device 50 includes, in addition to the configuration of the tactile sense transmission device 1 (Figure 1) in the first embodiment, a pressure sensor 51 that is integrated with the optical unit 2.

[0052] The pressure sensor 51 detects the pressure corresponding to the deformation of the left and right sides when it is in contact with each of the operator's fingertips from both the left and right sides.

[0053] The abdominal deformation detection unit 31 in this tactile sensation transmission device 50 detects the deformation state of the abdominal part of each fingertip based on the change in scattering characteristics analyzed by the scattering characteristic analysis unit 30 and the change in pressure detected by the pressure sensor 51.

[0054] As a result, the tactile sensation transmission device 50 is able to detect the deformation state of the pads of each of the operator's fingertips complementarily from not only the back of each fingertip but also the left and right side portions, thereby making it possible to significantly improve the accuracy of the tactile sensation data related to each fingertip.

[0055] Furthermore, the overall control unit 20 in the tactile sensation transmission device 50 calibrates default values ​​representing the scattering characteristics obtained from the scattering characteristic analysis unit 30 when each fingertip is in a non-contact state, based on the pressure detected by the pressure sensor 51 when the fingertip is in a non-contact state.

[0056] As a result, the tactile sensation transmission device 50 calibrates the deformation state of the pads of each of the operator's fingertips by calibrating the error of the detection method based on optical techniques at the back of each fingertip with a detection method based on physical techniques at the side of each fingertip, thereby making it possible to significantly improve the accuracy of the tactile sensation data for each fingertip.

[0057] (3) Configuration of the haptic transmission device according to the third embodiment In Figure 6, in which parts corresponding to those in Figure 1 are given the same symbols, the haptic transmission device 60 has, in addition to the configuration of the haptic transmission device 1 (Figure 1) in the first embodiment, a sensory transmission unit 61 that is worn on the arm (e.g., wrist) opposite the arm from which each fingertip acquires haptic data, and that transmits physical sensations based on the haptic data to the skin surface.

[0058] Based on the haptic data sent by the general control unit 20, the sensory transmission unit 61 transmits, as feedback, to the skin surface of the desired area, the distribution and transition of the pressure applied to the pads of the operator's fingertips.

[0059] The sensory transmission unit 61 has a tactile device (not shown) corresponding to each fingertip. Each tactile device is composed of a solenoid (a component that converts electrical energy into mechanical motion using electromagnetic force) that vibrates according to a frequency and amplitude based on the haptic data.

[0060] In addition to solenoids, various other devices that can provide relatively strong vibrations at relatively low frequencies or vibrations over a relatively wide frequency band, such as piezoelectric actuators, linear resonant actuators, voice coils, and eccentric rotation motors, may also be used as tactile devices.

[0061] As a result, with the tactile sensation transmission device 60, in the case of a patient with paralysis of the fingers whose fingertips are insensitive due to paralysis or the like, the operator can indirectly feel the tactile sensation through another part of the body that is sensitive to the sensation.

[0062] (4) Other Embodiments In the first to third embodiments, the haptic sense transmission devices 1, 50, and 60 are described as being applied to a human operator, but the present invention is not limited to this. They may also be applied to a robot having a hand mechanism that is the same as or similar to human fingers. Each fingertip of this robot has an elastic membrane (e.g., silicone rubber or resin) formed on its surface, which can be depressed toward the back side when the belly part is pressed from the front side.

[0063] As a result, the tactile sensation transmission devices 1, 50, and 60 store tactile sensation data for each fingertip of the robot, and by reading it out from the memory unit 21 as needed, it can be applied to another robot and the same tactile sensation can be reproduced for that robot down to a fine level (for example, the feeling of the fingers twisting).

[0064] Furthermore, if the tactile data corresponding to the tactile transmission device 1, 50, 60 applied to the operator is calibrated based on the robot tactile data corresponding to the tactile transmission device 1, 50, 60 applied to the robot hand, it is possible to significantly improve the accuracy of the tactile data for each fingertip of the operator.

[0065] Furthermore, in the above-described first and third embodiments, the light source section 10 of the optical unit 2 is described as being attached to or held on the back of each fingertip of the operator, and continuous light is irradiated onto the back. However, the present invention is not limited to this, and the light source section may be attached to or held on the side of each fingertip of the operator, and continuous light may be irradiated onto the side.

[0066] Similarly, in the above-described first and third embodiments, the case where the plurality of light receiving elements 12 constituting the light detection section 11 of the optical unit 2 are arranged on the back of each fingertip has been described, but the present invention is not limited to this, and the plurality of light receiving elements 12 constituting the light detection section 11 may be arranged on the side of each fingertip, or may be arranged on the back and side of each fingertip.

[0067] Furthermore, in the above-mentioned first to third embodiments, the scattering characteristics analyzed for each fingertip by the scattering characteristic analysis unit 30 in the tactile sense transmission devices 1, 50, and 60 are described as being represented as a light scattering phenomenon occurring in the internal space of each fingertip, but the present invention is not limited to this, and since the light source unit 10 is a light-emitting element that emits coherent light (near-infrared laser light) as continuous light, the scattering characteristic analysis unit 30 may further include phase information obtained from the detection signal output from the light detection unit 11 as the scattering characteristics.

[0068] As a result, in the tactile sensation transmission devices 1, 50, and 60, phase information can be obtained from scattered light in the light detection unit 11, and by detecting light received at multiple points on each fingertip, the scattering characteristics can be captured in more detail, making it possible to obtain tactile sensation data with relatively high accuracy.

[0069] Furthermore, in the above-mentioned second embodiment, the pressing force sensor 51 is described as being integral with the optical unit 2 so that it abuts against each of the operator's fingertips from both the left and right sides, but the present invention is not limited to this, and the pressing force sensor 51 may be integral with the optical unit 2 so that it abuts against each of the operator's fingertips from either the left or right side.

[0070] 1, 50, 60...tactile sensation transmission device, 2...optical unit, 3...control unit, 4...cable, 10...light source unit, 11...light detection unit, 12...light receiving element, 20...general control unit, 21...memory unit, 30...scattering property analysis unit, 31...abdominal deformation detection unit, 32...pressure force estimation unit, 40...pressure trial device, 41...fingertip holding unit, 42...pressure force application unit, 51...pressure force sensor, 61...sensory transmission unit.

Claims

1. A light source unit that is attached to or held on the back or side of each fingertip of an operator or robot and that irradiates the back or side with continuous light; a light detection unit that detects scattered light obtained as a result of the continuous light propagating inside each fingertip of the operator or robot; a scattering property analysis unit that analyzes the scattering properties, mainly forward scattering and backward scattering, of the spatial distribution within each fingertip based on the detection signal output from the light detection unit, for each fingertip; a control unit that stores in a memory unit, as default values, the scattering properties obtained when each fingertip is in a non-contact state, for the scattering properties for each fingertip analyzed by the scattering property analysis unit; an abdominal deformation detection unit that detects the deformation state of the abdomen of each fingertip based on changes in the scattering properties analyzed by the scattering property analysis unit, using the default values ​​for each fingertip read from the memory unit as a reference; and a pressure estimation unit that estimates the distribution and transition state of the pressure on the abdomen of each fingertip based on the deformation state of the abdomen of each fingertip detected by the abdominal deformation detection unit. wherein the control unit stores the distribution and transition of the pressure on the pad of each fingertip estimated by the pressure force estimation unit in the storage unit as haptic data for each fingertip.

2. The tactile sensation transmission device of claim 1, characterized in that when the pad of each finger is set as an elastic membrane that can be depressed toward the back side when pressed from the front side, the abdomen deformation detection unit detects the contact area when pressed from the front side of the elastic membrane, as well as the degree and direction of depression at the contact area, as the deformation state of the pad of each fingertip.

3. A tactile sensation transmission device as described in claim 1 or 2, characterized in that the light detection unit has multiple light receiving elements arranged on the back and / or sides of each fingertip, and synchronously combines the detection results of the scattered light from each of the light receiving elements to generate the detection signal.

4. A tactile sensation transmission device as described in claim 1 or 2, characterized in that the light source unit is composed of a light-emitting element that emits coherent light as the continuous light, and the scattering characteristic analysis unit includes, as the scattering characteristic, phase information obtained from the detection signal output from the light detection unit.

5. A tactile sensation transmission device as described in claim 1 or 2, characterized in that it is provided with a pressure sensor that detects pressure corresponding to deformation of one or both of the left and right sides of each fingertip of the operator or robot when the pressure sensor is in contact with the fingertip, and the abdominal deformation detection unit detects the deformation state of the abdominal part of each fingertip based on the change in the scattering characteristics analyzed by the scattering characteristic analysis unit and the change in the pressure detected by the pressure sensor.

6. The tactile sensation transmission device described in claim 5, characterized in that the control unit calibrates default values ​​representing the scattering characteristics obtained from the scattering characteristic analysis unit when each fingertip is in a non-contact state based on the pressure detected by the pressure sensor when each fingertip is in a non-contact state.

7. A tactile force transmission device as described in claim 1 or 2, further comprising a sensory transmission unit that is attached to or held at a desired part of the operator's upper limb and transmits physical sensations to the skin surface of the desired part, wherein the sensory transmission unit transmits, by feedback, to the skin surface of the desired part, the distribution and transition of the pressure of each of the operator's fingertips on the pads of the fingers, based on the tactile force data sent by the control unit.

8. A first step of irradiating the back or side of each fingertip of an operator or robot with continuous light and detecting scattered light resulting from the propagation of the continuous light inside each fingertip as a detection signal; a second step of analyzing, for each fingertip, scattering characteristics, mainly forward scattering and backward scattering, of the spatial distribution within each fingertip based on the detection signal detected in the first step; a third step of storing, in a memory unit, the scattering characteristics obtained when each fingertip is in a non-contact state, as default values ​​for the scattering characteristics of each fingertip analyzed in the second step; a fourth step of detecting the deformation state of the pad of each fingertip based on changes in the scattering characteristics analyzed by the scattering characteristic analysis unit, using the default values ​​for each fingertip read from the memory unit as a reference; and a fifth step of estimating the distribution and transition state of the pressure force on the pad of each fingertip based on the deformation state of the pad of each fingertip detected in the fourth step. and a sixth step of storing the distribution and transition of the pressure on the pad of each fingertip estimated in the fifth step in the storage unit as tactile data for each fingertip.

9. The tactile sensation transmission method described in claim 8, characterized in that in the fourth step, when the pad of each finger is set as an elastic membrane that can be depressed toward the back side when pressed from the front side, the contact area when pressed from the front side of the elastic membrane, as well as the degree and direction of depression at the contact area, are detected as the deformation state of the pad of each fingertip.

10. A tactile sensation transmission method as described in claim 8 or 9, characterized in that in the first step, a plurality of light receiving elements arranged on the back and / or sides of each fingertip are used to synchronously combine the detection results of the scattered light from each of the light receiving elements and generate the detection signal.

11. A tactile sensation transmission method as described in claim 8 or 9, characterized in that in the first step, coherent light is emitted as the continuous light, and in the second step, the scattering characteristics include phase information obtained from the detection signal output from the light detection unit.

12. A tactile sensation transmission method as described in claim 8 or 9, characterized in that it comprises a seventh step of detecting a pressure force corresponding to the deformation of one or both of the left and right side portions of each fingertip of the operator or robot while the fingertip is brought into contact with the left or right side portion, and in the fourth step, detecting the deformation state of the pad of each fingertip based on the change in the scattering characteristics analyzed in the second step and the change in pressure force detected in the seventh step.

13. The haptic sensation transmission method described in claim 12, characterized in that in the sixth step, a default value representing the scattering characteristics obtained from the second step when each fingertip is in a non-contact state is calibrated based on the pressure detected by the pressure sensor when each fingertip is in a non-contact state.

14. A haptic / force transmission method as described in claim 8 or 9, characterized in that it further comprises an eighth step of feeding back and transmitting the distribution and transition state of the pressure of each of the operator's fingertips on the abdomen as a physical sensation to the skin surface of a desired part of the operator's upper limb based on the haptic / force data sent by the sixth step.

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