JP2022113357A - Tactile sensor device and robot hand device using the same - Google Patents

Abstract

To provide a simple tactile sensor device which can detect a force in two axial directions, and a general-purpose robot hand device using the same.SOLUTION: A tactile sensor device includes a substrate 32, and a first flexible plate 34 erected on the substrate 32. The device includes a second flexible plate 36 which is a plate erected on the substrate 32, is positioned on the side part of the first flexible plate 34, and is arranged so that its width direction is parallel to a width direction of the first flexible plate 34. The device includes a connection part 38 for connecting tip parts of first and second flexible plates 34 and 36, and a pressure-receiving part 40 (first and second pressure-receiving plates 42 and 44) provided integrally with the connection part 38. The device includes deflection amount detection means 48 for detecting a deflection amount generated in the first and second flexible plates 34 and 36 when external forces Fx and Fz are applied to the pressure-receiving part 40. The deflection amount detection means 48 outputs a characteristic value corresponding to a deflection amount in an X-axis direction generated in the first and second flexible plates 34 and 36, as a detection signal.SELECTED DRAWING: Figure 2

Description

TECHNICAL FIELD The present invention relates to a tactile sensor device that detects an external force received when contacting a structure or the like, and a robot hand device that grips a workpiece with a plurality of fingers.

Conventionally, as disclosed in Patent Document 1, for example, first and second finger portions for gripping a workpiece are provided at the end of an arm, and a predetermined sensor system is provided at the tip of each finger portion. There was a robot hand that was used.

The structure of the sensor system is such that a large number of force sensors are attached to a substrate having a reference plane and a plurality of slopes. of sensors are used. When the robot hand grips a workpiece with the first and second fingers, the sensor system detects three-axis directions that the first and second fingers receive from the workpiece based on the detection results of the plurality of force sensors. The pressing forces and the moments about the three axes are calculated respectively.

Japanese Patent Application Laid-Open No. 2020-85810

The sensor system of Patent Document 1 is an advanced system that combines a large number of 6-axis force sensors, so the configuration is very complicated and the cost is high. Therefore, this sensor system is suitable for a high-grade robot hand device that handles precision parts, etc., but it is too high quality for a general-purpose robot hand device that handles ordinary articles, and the cost increases significantly, so it cannot be applied. It is difficult.

SUMMARY OF THE INVENTION It is an object of the present invention to provide a simple tactile sensor device capable of detecting forces in two axial directions, and a robot hand device using the same.

The present invention comprises a base, a first flexible plate erected on the base, and a plate erected on the base, the plate being positioned on the side of the first flexible plate, and a second flexible plate arranged so that the width direction thereof is parallel to the width direction of the first flexible plate; a pressure receiving portion provided integrally with the connecting portion; and deflection amount detecting means for detecting the amount of deflection generated in the first and second flexible plates when an external force is applied to the pressure receiving portion. and the pressure receiving portion is configured by a first pressure receiving plate extending from the connecting portion and facing the outer surface of the first flexible plate,
A coordinate system based on the base, wherein the direction in which the first and second flexible plates are erected with respect to the base is the positive direction of the Z axis, and the direction of the first and second flexible plates is When an XYZ three-dimensional coordinate system is defined in which the width direction is the Y-axis direction, when an external force in the X-axis direction is applied to the first pressure plate, this external force is applied to the first and second flexible plates through the connecting portion. When the external force is transmitted to the plate, both the first flexible plate and the second flexible plate bend in the same direction as the external force, and the external force in the Z-axis direction is applied to the first pressure receiving plate or the connecting portion , this external force is transmitted to the first and second flexible plates through the connecting portion, the first flexible plate bends in the X-axis positive direction or the X-axis negative direction, and the second flexible plate The first flexible plate is bent in a direction opposite to that of the first flexible plate, and the deflection amount detection means outputs a characteristic value corresponding to the amount of deflection in the X-axis direction generated in the first and second flexible plates as a detection signal. It is a tactile sensor device.

A fixed plate is erected on the base body, the front side and the back side of which face the inner surfaces of the first and second flexible plates, respectively, and the deflection amount detection means is configured to detect the first flexible plate with respect to the fixed plate. and a second position sensor for detecting the displacement amount of the second flexible plate in the X-axis direction with respect to the fixed plate. and the first and second position sensors may be capacitive or photoelectric sensors. Alternatively, the deflection amount detection means comprises a first strain sensor for detecting the strain amount of the first flexible plate and a second strain sensor for detecting the strain amount of the second flexible plate. and the first and second strain sensors may be strain gauge or piezoelectric sensors attached to the first and second flexible plates.

The pressure-receiving portion includes the first pressure-receiving plate and a plate-shaped second pressure-receiving plate extending from the connecting portion and facing the outer surface of the second flexible plate. When an external force in the X-axis direction is applied to the pressure receiving plate of , this external force is transmitted to the first and second flexible plates through the connecting portion, and the first and second flexible plates are separated from each other. Both bend in the same direction as the external force, and when an external force in the Z-axis direction is applied to the second pressure receiving plate or the connecting portion, this external force is transmitted to the first and second flexible plates through the connecting portion. Preferably, the first flexible plate bends in the X-axis positive direction or the X-axis negative direction, and the second flexible plate bends in the opposite direction to the first flexible plate.

Further, the present invention includes a gripping mechanism in which the above-described tactile sensor device is used as a tactile finger, and grips a workpiece with two fingers including the tactile finger. In the robot hand device, the base body is attached to the main body of the mechanism, and the pressure-receiving portion contacts the work when the work is gripped.

The two fingers are composed of the tactile finger and a non-tactile finger having no tactile function. , and the non-tactile finger portion hold the workpiece. Alternatively, the two fingers are composed of first and second tactile fingers, which are the two tactile fingers, and when the workpiece is gripped, the first tactile finger is A workpiece is sandwiched between the outer surface of one pressure receiving plate and the outer surface of the first pressure receiving plate of the second tactile finger portion. Alternatively, the two fingers are composed of first and second tactile fingers, which are the two tactile fingers, and when the work is gripped, the first tactile finger has the A workpiece is sandwiched between the outer surface of the first pressure receiving plate and the side end surface of the pressure receiving portion of the second tactile finger.

and an arm for moving the main body of the gripping mechanism, and a 6-axis force sensor attached to a connecting portion between the arm and the main body, wherein the 6-axis force sensor device moves the arm. As a reference, the external force and moment applied to the main body can be detected, and the external force calculated based on the detection signal of the deflection amount detection means of the tactile finger and the detection result of the force sensor are compared and analyzed. By doing so, it may be configured to detect an abnormality of the gripping mechanism.

According to the tactile sensor device of the present invention, it is possible to accurately detect forces in two axial directions with a simple and unique configuration in which two flexible plates and a pressure receiving portion are combined. In addition, since the robot hand device of the present invention uses the above-described tactile sensor device as the tactile finger portion of the gripping mechanism, the gripping force applied to the workpiece when gripping the workpiece and the obstacles caused by mistake during the transfer of the workpiece can be prevented. It is possible to accurately detect contact with the robot hand device, and to easily and inexpensively monitor the operation status of the robot hand device and the presence or absence of an abnormality.

1 is a perspective view showing the appearance of a robot hand device according to first to third embodiments of the present invention; FIG. 1 is a perspective view (a) showing a tactile sensor device according to a first embodiment of the present invention, and a diagram showing a capacitive position sensor that constitutes deflection amount detection means; FIG. Figures (a) to (d) show how the flexible plate bends when an external force is applied to the pressure-receiving part of the tactile sensor device of FIG. It is a chart showing. It is the front view (a) which shows the holding|gripping mechanism which the robot hand apparatus of 1st embodiment has, and the chart (b) which shows the example of a detection item. It is the front view (a) which shows the holding|gripping mechanism which the robot hand apparatus of 2nd embodiment has, and the chart (b) which shows the example of a detection item. It is the front view (a) which shows the holding|gripping mechanism which the robot hand apparatus of 3rd embodiment has, and the chart (b) which shows the example of a detection item. FIG. 11(a) shows a modification of the deflection amount detection means of the tactile sensor device, and parts (b) to (g) show modifications of the first and second flexible plates. It is the perspective view (a) which shows the modification of the pressure-receiving part which a touch sensor apparatus has, and the figure (b) which shows the modification of a 1st and 2nd flexible board. FIG. 9A is a perspective view showing the appearance of a modification of the robot hand device according to the first to third embodiments, and FIG. 8B is a perspective view showing the appearance of a 6-axis force sensor;

A first embodiment of a tactile sensor device and a robot hand device according to the present invention will be described below with reference to FIGS. 1 to 4. FIG. As shown in FIG. 1, the robot hand device 10 of this embodiment includes an arm 12, a gripping mechanism 14 attached to the tip of the arm 12, and a controller (not shown) that controls the operations of the arm 12 and the gripping mechanism 14. It is equipped with

The gripping mechanism 14 has a main body formed by a first substrate 16 fixed laterally to the end face of the arm 12 and a second substrate 18 vertically fixed to the lower surface of the first substrate 16. A fixed finger portion 20 and a moving finger portion 22, which are two fingers for gripping the work W, are installed.

The fixed finger 20 is fixed to the end of the side surface of the second substrate 18, and the moving finger 22 is supported by a ball screw 24 extending from the side surface of the fixed finger 20 in the α-axis direction. The ball screw 24 is screwed into a female screw hole 22a formed through the moving finger portion 22, and by rotating the ball screw 24 around the α axis by a driving motor 26, the moving finger portion 22 is moved to the α axis. can be moved in any direction.

The arm 12 moves the main body of the gripping mechanism 14 horizontally (α-axis direction, γ-axis direction) and It performs an operation of moving in the vertical direction (γ-axis direction).

In the case of the robot hand device 10, the fixed finger portion 20 is a non-tactile finger portion 28 which is a prismatic structure having no tactile function, and the moving finger portion 22 is a tactile finger portion 30 ( This is the tactile sensor device 30) of the first embodiment.

As shown in FIG. 2, the tactile sensor device 30 includes a rectangular base 32 and first and second flexible plates 34 and 36 erected on the base 32 . The second flexible plate 36 is positioned to the side of the first flexible plate 34 and arranged such that its width direction is substantially parallel to the width direction of the first flexible plate 34 . The first and second flexible plates 34 and 36 have substantially the same arc shape, and have a shape that bulges outward so that their central portions are separated from each other.

The distal end portions of the first and second flexible plates 34 and 36 are connected by a connecting portion 38, and a pressure receiving portion 40 for receiving an external force extends integrally from the connecting portion 38. As shown in FIG. The pressure-receiving portion 40 is a portion that receives an external force. and a second pressure-receiving plate 44 facing the outer surface of the flexible plate 36 . Further, a fixed plate 46 is erected on the base 32 so that its front side and back side face the inner surfaces of the first and second flexible plates 34 and 36, respectively.

The substrate 32, the first and second flexible plates 34 and 36, the connecting portion 38, the pressure receiving portion 40, and the fixed plate 46 described so far are made of conductive metal materials such as aluminum alloy, iron, and stainless steel. are integrally formed.

Here, in a coordinate system with the base 32 as a reference, the direction in which the first and second flexible plates 34 and 36 are erected with respect to the base 32 is the Z-axis positive direction, and the first and second An XYZ three-dimensional coordinate system is defined in which the width direction of the flexible plates 34 and 36 is the Y-axis direction. The XYZ three-dimensional coordinate system will be used in the following description.

The tactile sensor device 30 is provided with deflection amount detection means 48 for detecting the amount of deflection in the X-axis direction generated in the first and second flexible plates 34 and 36 when an external force is applied to the pressure receiving portion 40. The deflection amount detection means 48 includes a first position sensor for detecting the amount of displacement of the first flexible plate 34 with respect to the fixed plate 46 in the X-axis direction, and a second position sensor that detects the amount of displacement in the X-axis direction.

The first and second position sensors are capacitive sensors of substantially the same characteristics. The first position sensor, as shown in FIG. 2(b), has an electrode layer 48b disposed on the left side of the fixed plate 46 via an insulating layer 48a. A change in capacitance C1 generated between the first flexible plate 34 and the first flexible plate 34 is detected, and a detection signal corresponding to the amount of deflection in the X-axis direction generated in the first flexible plate 34 is output. Similarly, the second position sensor has an electrode layer 48b disposed on the right side of the fixed plate 46 with an insulating layer 48a interposed therebetween. , and outputs a detection signal corresponding to the amount of deflection in the X-axis direction that has occurred in the second flexible plate 36 .

As shown in FIGS. 3(a) and 3(b), when an external force Fx in the X-axis direction is applied to the first or second pressure receiving plates 42, 44, the external force Fx is applied to the first and second pressure receiving plates 42, 44 through the connecting portion 38. It is transmitted to the flexible plates 34, 36, and both the first flexible plate 34 and the second flexible plate 36 bend in the same direction as the external force Fx. 3(c) and 3(d), when an external force Fz in the Z-axis direction is applied to the first pressure receiving plate 42, the second pressure receiving plate 44, or the connecting portion 38, the external force Fz is applied to the connecting portion 38. to the first and second flexible plates 34 and 36, the first flexible plate 34 bends in the X-axis positive direction or the X-axis negative direction, and the second flexible plate 36 bends in the first flexible It bends in the direction opposite to the plate 34 .

The amounts of change ΔC1 and ΔC2 of the capacitances C1 and C2 with respect to the external forces Fx and Fz are shown in the table of FIG. 3(e). The capacitances C1 and C2 when no external force is applied are "C1=C2=Co".

For example, when an external force Fx (>0) in the positive direction of the X axis is applied, "ΔC1 = +ΔC" and "ΔC2 = -ΔC" are applied, and when an external force Fx (<0) in the negative direction of the X axis is applied, " ΔC1=-ΔC” and ΔC2=+ΔC. Therefore, the magnitude and direction of the external force Fx (positive direction or negative direction) can be detected by acquiring the detection signal of the deflection amount detection means 48 and calculating the characteristic value corresponding to "ΔC1-ΔC2". can. Also, when an external force Fz (>0) in the positive direction of the Z-axis is applied, "ΔC1 = +ΔC" and "ΔC2 = +ΔC" are applied, and when an external force Fz (<0) in the negative direction of the Z-axis is applied, " ΔC1=-ΔC” and ΔC2=-ΔC. Therefore, the magnitude and direction of the external force Fz (positive direction or negative direction) can be detected by acquiring the detection signal of the deflection amount detection means 48 and calculating the characteristic value corresponding to "ΔC1+ΔC2". can.

The gripping mechanism 14 of the robot hand device 10 includes, as shown in FIGS. sensor device 30). The tactile finger portion 30 is provided with a female screw hole 22a passing through the base 32 in the X-axis direction, and is arranged so that the positive direction of the X-axis of the tactile finger portion 30 coincides with the positive direction of the α-axis of the robot hand device 10, A ball screw 24 is inserted into and screwed into the female screw hole 22a so as to be movable in the α-axis direction. Then, the non-tactile finger portion 28 and the outer surface of the first pressure-receiving plate 42 of the tactile finger portion 30 facing each other sandwich (grip) the work W and transfer the work W to another place.

The calculation means for acquiring the detection signal of the deflection amount detection means 48 and calculating the external forces Fx and Fz may be provided inside a controller (not shown) located away from the arm 12 and the grip portion 14. However, it is preferable to install a dedicated computing board on the main body of the gripping mechanism 14 . In the former case, since minute detection signals output from the first and second position sensors are transmitted to the controller through a long cable, errors are likely to occur due to external noise. On the other hand, in the latter case, since the arithmetic board is arranged near the deflection amount detection means 48, external noise is less likely to enter, and errors are less likely to occur when calculating the external forces Fx and Fz. In addition, since the signals output from the arithmetic board to the controller (the signals resulting from the calculation of the external forces Fx and Fz) are not minute signals, they can be transmitted to the controller without any problem.

In the case of the robot hand device 10, a plurality of determinations shown in FIG. For example, as shown in No. 1, it can be determined that the gripping mechanism 14 has gripped the workpiece W when the external force Fx>0 is detected. Further, as shown in No. 2, when the external force Fx>0 is detected, it can be determined that the gripping force F1 of the workpiece W is Fx. Further, as shown in No. 3, when the external force Fx<0 is detected, it can be determined that the second pressure receiving plate 44 of the tactile finger portion 30 has come into contact with an obstacle such as a wall. Further, as shown in No. 4, when the external force Fz<0 is detected, it can be determined that the connecting portion 38 of the tactile finger portion 30 has come into contact with an obstacle such as the floor. Further, as shown in No. 5, when the external force Fz>0 is detected, it can be determined that the weight F2 of the workpiece W is Fz+k (k is a previously derived correction value).

As described above, according to the tactile sensor device 30, the simple and unique configuration in which the two flexible plates 34 and 36 and the pressure receiving portion 40 are combined makes it possible to accurately detect forces in two axial directions. . Since the robot hand device 10 uses the tactile sensor device 30 as the tactile finger portion 30 of the gripping mechanism 14, the gripping force applied to the work W when gripping the work W and the erroneous obstacles during transfer of the work W can be prevented. It is possible to accurately detect contact with an object, etc., and to easily and inexpensively monitor the operation status of the robot hand device 10 and the presence or absence of an abnormality.

Next, a second embodiment of the robot hand device of the present invention will be described with reference to FIGS. 1 and 5. FIG. Here, the same configurations as those of the robot hand device 10 described above are denoted by the same reference numerals, and descriptions thereof are omitted.

The robot hand device 50 of this embodiment has the same overall configuration as the robot hand device 10, but differs in that both the fixed finger portion 20 and the moving finger portion 22 are tactile finger portions 30 (tactile sensor devices 30). The point is that

In the grasping mechanism 14 of the robot hand device 50, as shown in FIGS. 1 and 5A, the tactile finger portion 30 as the fixed finger portion 20 has its own X-axis negative direction aligned with the α-axis of the robot hand device 10. They are arranged in the positive direction, and the base 32 is fixed to the second substrate 18 of the main body. The tactile finger 30 as the moving finger 22 is provided with a female screw hole 22a that penetrates the base 32 in the X-axis direction, and is arranged so that the positive direction of the X-axis of itself coincides with the positive direction of the α-axis of the robot hand device 10. A ball screw 24 is inserted into and screwed into the female screw hole 22a so as to be movable in the α-axis direction. Then, the work W is sandwiched (gripped) between the outer surfaces of the first pressure receiving plates 42 of the two tactile fingers 30 facing each other, and the work W is transferred to another place.

In the case of the robot hand device 50, it is possible to make a plurality of determinations shown in FIG. Let Fx1 and Fz1 be the external forces Fx and Fz applied to the tactile finger 30 as the moving finger 22, and Fx2 and Fz2 be the external forces Fx and Fz applied to the tactile finger 30 as the fixed finger 20. For example, as shown in No. 1, it can be determined that the gripping mechanism 14 has gripped the workpiece W when external forces Fx1>0 and Fx2>0 are detected. Also, as shown in No. 2, when external forces Fx1>0 and Fx2>0 are detected, it can be determined that the gripping force F1 of the workpiece W is (Fx1+Fx2)/2. Also, as shown in No. 3, when an external force Fx1<0 or Fx2<0 is detected, the second pressure receiving plate 44 of the tactile finger portion 30 for which Fx is detected hits an obstacle such as a wall. It can be determined that contact has occurred. Further, as shown in No. 4, when the external force Fz1 < 0 or the external force Fz2 < 0 was detected, the connecting portion 38 of the tactile finger 30 for which Fz was detected came into contact with an obstacle such as the floor. can be determined. Also, as shown in No. 5, when external forces Fz1>0 and Fz2>0 are detected, it can be determined that the weight F2 of the workpiece W is Fz1+Fz2. Furthermore, as shown in No. 6, when external forces Fz1>0 and Fz2>0 are detected, the deviation of the center of gravity of the workpiece W (in the α-axis direction) can be calculated from the ratio between Fz1 and Fz2.

In this manner, the robot hand device 50 can obtain the same effects as the robot hand device 10 described above, and furthermore, can monitor the operation status of the robot hand device 50 and whether or not an abnormality has occurred in more detail. .

Next, a third embodiment of the robot hand device of the present invention will be described with reference to FIGS. 1 and 6. FIG. Here, the same configurations as those of the robot hand device 50 described above are denoted by the same reference numerals, and descriptions thereof are omitted.

The robot hand device 52 of this embodiment has the same overall configuration as the robot hand device 50, and both the fixed finger portion 20 and the moving finger portion 22 are tactile finger portions 30 (tactile sensor devices 30). However, what is different is the angle at which the tactile finger 30, which is the moving finger 20, is worn.

In the grasping mechanism 14 of the robot hand device 52, as shown in FIGS. 1 and 6A, the tactile finger portion 30 as the fixed finger portion 20 has its own X-axis negative direction aligned with the α-axis of the robot hand device 10. They are arranged in the positive direction, and the base 32 is fixed to the second substrate 18 of the main body. The tactile finger 30 as the moving finger 22 is provided with a female screw hole 22a passing through the base 32 in the Y-axis direction, and the negative Y-axis direction of the tactile finger 30 is the positive α-axis direction of the robot hand device 10 . , and the ball screw 24 is inserted into and screwed into the female screw hole 22a so as to be movable in the α-axis direction. The outer surface of the first pressure receiving plate 42 of the tactile finger 30 as the fixed finger 20 and the pressure receiving portion 40 of the tactile finger 30 as the moving finger 22 (the first and second pressure receiving plates 42, 44) are opposed to each other, and the work W is sandwiched (held) between them to transfer the work W to another place. The haptic fingers 30 as the moving fingers 22 are structured so that the work W does not come into contact with the first and second flexible plates 34 and 36 and the fixed plate 46 when the work W is gripped.

In the case of the robot hand device 52, it is possible to make a plurality of determinations shown in FIG. Let Fx1 and Fz1 be the external forces Fx and Fz applied to the tactile finger 30 as the moving finger 22, and Fx2 and Fz2 be the external forces Fx and Fz applied to the tactile finger 30 as the fixed finger 20. For example, as shown in No. 1, it can be determined that the gripping mechanism 14 has gripped the workpiece W when the external force Fx2>0 is detected. Further, as shown in No. 2, when the external force Fx2>0 is detected, it can be determined that the value of the gripping force F1 of the workpiece W is Fx2. Further, as shown in No. 3, when the external force Fx2<0 is detected, it can be determined that the second pressure receiving plate 44 of the tactile finger portion 30 as the fixed finger portion 20 has come into contact with an obstacle such as a wall. . Further, as shown in No. 4, when an external force Fz1<0 or Fz2<0 is detected, it is assumed that the connecting portion 38 of the tactile finger portion 30 for which Fz is detected has come into contact with an obstacle such as the floor. I can judge. Also, as shown in No. 5, when external forces Fz1>0 and Fz2>0 are detected, it can be determined that the weight F2 of the workpiece W is Fz1+Fz2. Further, as shown in No. 6, when external forces Fz1>0 and Fz2>0 are detected, the deviation of the center of gravity of the workpiece W (in the α-axis direction) can be calculated from the ratio between Fz1 and Fz2. Furthermore, as shown in No.7, when the external force Fx1≠0 and Fx2>0 is detected, it is determined that the magnitude of the moment M of the workpiece W is Fx1×L (L is the distance between the two fingers). , and the direction of the moment M can also be specified depending on whether Fx1 is positive or negative.

In this way, the robot hand device 52 can obtain the same effects as those of the robot hand devices 10 and 50 described above, and furthermore, the operation status of the robot hand device 52 and the presence or absence of an abnormality can be monitored in more detail. can be done.

Note that the tactile sensor device of the present invention is not limited to the configuration of the above embodiment. For example, in the case of the tactile sensor device 30 described above, as shown in FIG. , C2 using a capacitive position sensor. However, the structure shown in FIG. 2B is a structure that can be applied when the flexible plates 34, 36, the base 32, etc. are integrally formed of a conductive metal material. 36, the base 32, etc., are formed of a non-conductive synthetic resin material, etc., electrodes 48b are provided on the front and back sides of the fixed plate 46, and the flexible plates 34, 36 facing the electrodes 48b are provided. An electrode 48b is also provided on the surface. Also, the electrostatic capacity type position sensor may be replaced with a photoelectric position sensor that detects a change in the separation distance between the flexible plates 34 and 36 and the fixed plate 46 . As shown in FIG. 7A, the strain amount detecting means is a strain gauge type strain sensor having a pair of strain gauges Rg1 and Rg2 arranged on the surfaces of the flexible plates 34 and 38, or a pair of piezoelectric elements. A piezoelectric strain sensor may also be used, and similar effects can be obtained. Moreover, when using a strain sensor, the fixing plate 46 can be omitted.

The shape of the first and second flexible plates is such that when an external force Fx is applied to the pressure receiving portion, both the first and second flexible plates flex in the same direction as the external force Fx, and the external force Fz is applied to the connecting portion, etc. Any shape may be employed as long as the first and second flexible plates bend in mutually opposite directions (X-axis positive direction and X-axis negative direction) when applied. Moreover, the shape of the portion of the base on which the first and second flexible plates are erected and the shape of the connecting portion may be any shape that does not hinder the bending motion of the two flexible plates. Therefore, the shapes of the first and second flexible plates 34, 36, the base 32, and the connecting portion 38 can be changed, for example, to shapes as shown in FIGS. A working effect is obtained. Further, the connecting portion and the pressure receiving portion may be integrally formed of the same material, or may be integrally formed of different materials.

In the tactile sensor device 30 described above, the two pressure receiving plates 42 and 44 constitute the pressure receiving portion 40. However, like the tactile sensor device 30x shown in FIG. The unit 40 may be configured, and the structure can be made simpler. Further, as in the tactile sensor device 30y shown in FIG. 8B, the pressure receiving portion 40 is configured by only the first pressure receiving plate 42, and the two flexible plates 34 and 36 are arranged so as not to overlap in the thickness direction. , the thickness of the base 32 may be reduced, and the thickness dimension D of the tactile sensor device 30y can be shortened. However, if the robot hand devices 10, 50, 52 are configured using the tactile sensor devices 30x, 30y, some determinations ( For example, judgment No. 3) may not be possible.

Further, the robot hand device of the present invention is not limited to the above embodiments. For example, in FIGS. 1, 4(a), 5(a), and 6(a), the left fingers 28 and 30 are the fixed finger 20 and the right finger 30 is the moving finger 22. However, the fingers 28 and 30 on the left side may be the moving fingers and the finger 30 on the right side may be the fixed finger, and the same effect can be obtained. Also, both the left fingers 28, 30 and the left finger 30 can be movable fingers.

The gripping mechanism 14 described above employs a configuration in which the ball screw 24 is rotated by the driving motor 26 as means for moving the moving finger 22 in the α-axis direction. good. Further, the structure of the main body (first and second substrates 16 and 18) of the gripping mechanism 14 shown in FIG. 1 and the structure of the connecting portion between the main body and the arm 12 are also capable of the intended operation of the present invention. can be changed to another structure.

The determination contents shown in FIGS. 4(b), 5(b), and 6(b) are only examples, and the actual determination depends on the application of the robot hand device, the type of work, etc. can be freely determined according to

In addition, as in a modified robot hand device 54 shown in FIGS. It may be configured to be used together. The robot hand device 54 has the same configuration as the robot hand devices 10, 50, and 52 described above, and further has a 6-axis force sensor at the connecting portion between the arm 12 and the main body (first substrate 16) of the gripping mechanism 14. A sensor 56 is attached. The 6-axis force sensor 56 can detect external forces in the α-, β-, and γ-axis directions applied to the main body of the gripping mechanism 14, and moments around the respective axes, with the arm 12 as a reference.

Among the external forces detected by the tactile fingers 30, there are external forces that can be detected even by the 6-axis force sensor 56. If the gripping mechanism 14 is normal, both detection results are Generally agree. However, if the gripping mechanism 14 is operated for a long period of time, the constituent members will be deformed or the rigidity of the mechanism will deteriorate, so the difference between the two detection results will gradually increase. Therefore, by comparing and analyzing both detection results, an abnormality in the gripping mechanism 14 can be accurately detected, and maintenance or replacement can be performed at an appropriate timing. It should be noted that the six-axis force sensor 56 only needs to have excellent durability, and it is not necessary to select a particularly high-precision/high-sensitivity (expensive) sensor.

10, 50, 52, 54 robot hand device 14 gripping mechanism 16 first substrate (main body of gripping mechanism)
18 Second substrate (main body of gripping mechanism)
28 non-tactile fingers 30, 30x, 30y tactile sensor device (tactile fingers)
32 base 34 first flexible plate 36 second flexible plate 38 connecting portion 40 pressure receiving portion 42 first pressure receiving plate 44 second pressure receiving plate 46 fixed plate 48 deflection amount detection means 56 force sensor
C1, C2 capacitance
Fx, Fz External force
Rg1, Rg2 Strain gauge

Claims (9)

A base, a first flexible plate erected on the base, and a plate erected on the base, the plate being positioned on the side of the first flexible plate and extending in the width direction of itself. a second flexible plate arranged to be parallel to the width direction of the first flexible plate; a connecting portion connecting tip portions of the first and second flexible plates; and the connecting portion and a deflection amount detection means for detecting the amount of deflection generated in the first and second flexible plates when an external force is applied to the pressure receiving section, The pressure receiving portion is configured by a first pressure receiving plate extending from the connecting portion and facing the outer surface of the first flexible plate,
A coordinate system based on the base, wherein the direction in which the first and second flexible plates are erected with respect to the base is the positive direction of the Z axis, and the direction of the first and second flexible plates is When defining an XYZ three-dimensional coordinate system with the width direction as the Y-axis direction,
When an external force in the X-axis direction is applied to the first pressure-receiving plate, this external force is transmitted to the first and second flexible plates through the connecting portion, thereby both of the flexible plates flex in the same direction as the external force;
When an external force in the Z-axis direction is applied to the first pressure-receiving plate or the connecting portion, the external force is transmitted to the first and second flexible plates through the connecting portion, and the first flexible plate moves to the X direction. bending in the positive axial direction or the negative X-axis direction, the second flexible plate bending in the direction opposite to the first flexible plate;
The tactile sensor device, wherein the deflection amount detection means outputs a characteristic value corresponding to the deflection amount in the X-axis direction generated in the first and second flexible plates as a detection signal. A fixing plate is erected on the base body, the front side and the back side of which are opposed to the inner surfaces of the first and second flexible plates, respectively;
The deflection amount detection means includes a first position sensor for detecting a displacement amount of the first flexible plate in the X-axis direction with respect to the fixed plate, and a displacement amount of the second flexible plate in the X-axis direction with respect to the fixed plate. 2. The tactile sensor device according to claim 1, further comprising a second position sensor for detecting the amount of displacement of said first and second position sensors, wherein said first and second position sensors are capacitive or photoelectric sensors. The deflection amount detection means comprises a first strain sensor that detects the strain amount of the first flexible plate and a second strain sensor that detects the strain amount of the second flexible plate, 2. The tactile sensor device according to claim 1, wherein said first and second strain sensors are strain gauge type or piezoelectric type sensors attached to said first and second flexible plates. The pressure-receiving portion is composed of the first pressure-receiving plate and a plate-shaped second pressure-receiving plate extending from the connecting portion and facing the outer surface of the second flexible plate,
When an external force in the X-axis direction is applied to the second pressure-receiving plate, the external force is transmitted to the first and second flexible plates through the connecting portion, and the first flexible plate and the second flexible plate both of the flexible plates flex in the same direction as the external force;
When an external force in the Z-axis direction is applied to the second pressure receiving plate or the connecting portion, this external force is transmitted to the first and second flexible plates through the connecting portion, and the first flexible plate moves to the X direction. 4. The tactile sensor device according to any one of claims 1 to 3, wherein said second flexible plate bends in a direction opposite to said first flexible plate and bends in a positive axial direction or a negative X-axis direction. The tactile sensor device according to any one of claims 1 to 4 is used as a tactile finger, and has a gripping mechanism for gripping a workpiece with two fingers including the tactile finger,
The robot hand device according to claim 1, wherein the tactile fingers are attached to the main body of the gripping mechanism, and the pressure-receiving portion abuts the work when the work is gripped. The two fingers are composed of the tactile finger and a non-tactile finger having no tactile function,
6. The robot hand device according to claim 5, wherein the work is held between the outer surface of the first pressure receiving plate of the tactile finger and the non-tactile finger while gripping the work. The two fingers are composed of first and second tactile fingers, which are the two tactile fingers,
The workpiece is held between the outer surface of the first pressure receiving plate of the first tactile finger and the outer surface of the first pressure receiving plate of the second tactile finger. 6. The robot hand device according to claim 5. The two fingers are composed of first and second tactile fingers, which are the two tactile fingers,
While gripping a work, the work is sandwiched between the outer surface of the first pressure-receiving plate of the first tactile finger and the side end surface of the pressure-receiving portion of the second tactile finger. 6. The robot hand device according to claim 5. An arm for moving the main body of the gripping mechanism, and a 6-axis force sensor attached to a connection portion between the arm and the main body, wherein the 6-axis force sensor device uses the arm as a reference. capable of detecting an external force and moment applied to the main body,
9. An abnormality of the gripping mechanism is detected by comparing and analyzing the external force calculated based on the detection signal of the deflection amount detection means of the tactile finger portion and the detection result of the force sensor. A robotic hand device according to any one of the preceding claims.

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