JP2013113760A - Detection device, electronic apparatus, and robot - Google Patents

Abstract

To provide a detection device for detecting an external force with high accuracy.
A detection device for detecting an external force includes a first substrate having a plurality of pressure sensors arranged around a reference point and a second substrate having protrusions. The first substrate 10 has flexibility. The protrusions 22 are arranged so that the center of gravity G is located at a position overlapping with the reference point P, and the tip is in contact with the pressure sensor 12. Since the 1st board | substrate 10 deform | transforms according to external force, the detection apparatus 1 which detects the magnitude | size and direction of external force with high precision can be provided.
[Selection] Figure 1

Description

  The present invention relates to a detection device, an electronic device, and a robot.

  As a detection device for detecting an external force, detection devices described in Patent Documents 1 and 2 are known. Application of such a detection apparatus to a touch panel, a tactile sensor of a robot, or the like is being studied. The detection device of Patent Document 1 is configured to detect a pressure distribution from a deformation amount of a protrusion using a pressure-receiving sheet in which weight-like protrusions are substantially uniformly arranged on the back surface. The detection device of Patent Document 2 has a configuration in which a plurality of columnar protrusions are arranged in a grid pattern on the surface of a pressure-receiving sheet, and a conical protrusion is provided on the back surface of a portion obtained by equally dividing the periphery of these surface protrusions. .

Japanese Patent Laid-Open No. 60-135834 JP-A-7-128163

However, the detection device of Patent Document 1 has a problem in that it cannot measure the in-plane force (sliding force) of the external force applied to the measurement surface. In the detection device of Patent Document 2, it is possible to detect an external force as a three-dimensional force vector, but the detection limit of the external force is limited by the degree of deformation of the protrusion. As described above, the detection devices of Patent Documents 1 and 2 have a problem that the magnitude and direction of the external force cannot be detected with high accuracy.
Further, in the detection device of Patent Document 1, the spindle-shaped protrusions are easily broken, and in the detection device of Patent Document 2, the columnar protrusions are easily broken. That is, the conventional detection device has a problem that the protrusion is easily broken, the life of the detection device is short, and the durability is low.

  SUMMARY An advantage of some aspects of the invention is to solve at least a part of the problems described above, and the invention can be implemented as the following forms or application examples.

(Application Example 1) A detection device according to this application example is a detection device that detects an external force, and includes a first substrate having a plurality of pressure sensors arranged around a reference point, and a second substrate having a protrusion. The first substrate is flexible, and the protrusion is arranged such that the center of gravity is located at a position overlapping the reference point and the tip is in contact with the pressure sensor.
According to this configuration, the first substrate (a plurality of pressure sensors) that abuts the protrusion can be displaced or deformed according to the external force. In comparison, the detection accuracy of the magnitude and direction of the external force can be increased. Specifically, a strong pressure value is detected by a pressure sensor having protrusions in the direction of external force action, and a weak pressure value is detected by a pressure sensor having no protrusions in the direction of action of external force. As a result, different pressure values are detected by the respective pressure sensors, and the magnitude and direction of the external force including the sliding force (the component of the external force acting in parallel with the first substrate) are measured with high accuracy from these detected values. I can do things.

Application Example 2 In the detection device according to the application example described above, it is preferable that the surface on which the external force acts is provided on the first substrate.
According to this configuration, since an external force is applied from one surface forming the first substrate, it is possible to fix the second substrate having the protrusion and measure the external force from the displacement or deformation of the first substrate.

Application Example 3 In the detection device according to the application example, it is preferable that the protrusion is formed of a hard body.
According to this configuration, since the projection is a strong hard body, even if an external force is applied to the detection device, the deformation and displacement of the projection are very small, and therefore the external force can be accurately measured. Further, it is possible to reduce the possibility that the protrusion is damaged during the use of the detection device. Therefore, it is possible to increase the durability of the detection device and extend its life.

Application Example 4 In the detection device according to the application example, it is preferable that the first substrate and the second substrate are connected via an elastic body.
According to this configuration, the first substrate can be easily displaced and deformed according to the action of external force, so that the detection sensitivity can be increased.

Application Example 5 In the detection device according to the application example described above, it is preferable that the pressure sensor is arranged point-symmetrically with respect to the reference point.
According to this configuration, the distance from the reference point to each pressure sensor is equal between the pressure sensors in a point-symmetric relationship, so the relationship between the deformation amount of the first substrate and the pressure value detected by each pressure sensor However, the pressure sensors having a point-symmetrical relationship are equal to each other. If the pressure sensors are arranged at different distances from the reference point, the pressure values detected by the pressure sensors are all different even if the deformation amount of the protrusion is the same. For this reason, when various calculations are performed using the detected value, a correction coefficient corresponding to the arrangement position of each pressure sensor is required. On the other hand, according to this configuration, the relationship between the deformation amount of the first substrate and the pressure value detected by each pressure sensor is equal between the pressure sensors that are point-symmetrical, and therefore the correction coefficient between these pressure sensors. Is no longer necessary. Therefore, it becomes easy to calculate the direction and magnitude of the external force from the pressure value detected by each pressure sensor, and the external force can be detected efficiently.

Application Example 6 In the detection device according to the application example, it is preferable that the pressure sensors are arranged in a matrix in two directions orthogonal to each other.
According to this configuration, the row direction or the column direction can be defined as the X axis or the Y axis with respect to one surface of the first substrate on which the external force acts, and the X axis component and the Y axis component of the external force are separately measured. Things can be done easily. That is, it becomes easy to decompose the sliding force into two in-plane components.

Application Example 7 In the detection device according to the application example, it is preferable that the pressure sensors are arranged in at least 4 rows and 4 columns in two directions orthogonal to each other.
According to this configuration, since the number of pressure sensors to be arranged increases, it is possible to obtain the direction and magnitude in which an external force acts based on many pressure values detected by a large number of pressure sensors. That is, the external force can be detected with high accuracy.

Application Example 8 In the detection device according to the application example described above, it is preferable that a plurality of protrusions are formed on the second substrate, and the protrusions are arranged apart from each other.
In the detection apparatus, a single protrusion is used as a unit detection region for a plurality of pressure sensors. Therefore, according to this configuration, when the detection apparatus has a plurality of unit detection areas, the unit detection areas can be arranged apart from each other. Therefore, when the first substrate is elastically deformed, a certain amount of deformation of the first substrate in a direction parallel to one surface of the first substrate can be allowed. That is, it is possible to suppress a situation in which the pressure sensor corresponding to the first protrusion contacts the second protrusion located next to the first protrusion and malfunctions as a result of the deformation of the first substrate. For this reason, it is possible to detect the external force more accurately than when a plurality of protrusions are arranged in contact with each other.

Application Example 9 In the detection device according to the application example described above, a function value is calculated using the pressure value detected by the pressure sensor and the position of the pressure sensor with respect to the reference point as variables, and a predetermined value is used using the value. It is preferable to provide an arithmetic device that performs the above operations.
According to this configuration, the magnitude and direction of the external force can be measured relatively accurately with a small simple arithmetic device without using a large arithmetic device.

Application Example 10 An electronic apparatus according to this application example includes the detection device according to the application example.
According to this configuration, since the above-described detection device is provided, an electronic device capable of detecting the direction and magnitude of the external force with high accuracy can be provided.

Application Example 11 In the electronic device according to the application example described above, it is preferable that the electronic device includes a housing, and the second substrate forms a part of the housing.
According to this configuration, the electronic device can be easily manufactured, and the failure of the detection device can be easily repaired only by replacing the first substrate when the detection device fails.

Application Example 12 A robot according to this application example includes the detection device according to the application example.
According to this configuration, since the above-described detection device is provided, a robot capable of detecting the direction and magnitude of the external force with high accuracy can be provided.

Application Example 13 In the robot according to the application example described above, it is preferable that the robot has a gripping portion, and the second substrate forms a part of the gripping portion.
According to this configuration, the robot can be easily manufactured, and the failure of the detection device can be easily repaired by simply replacing the first substrate when the detection device fails.

1 is a diagram illustrating a schematic configuration of a detection device according to Embodiment 1. FIG. FIG. 3 is a diagram illustrating a schematic configuration of a first substrate according to the first embodiment. The figure explaining the method to detect the external force which acts on a unit detection area. FIG. 3 is a diagram illustrating a coordinate system of a unit detection region S according to the first embodiment. FIG. 3 is a view showing a pressure distribution in the vertical direction by the pressure sensor according to the first embodiment. FIG. 3 is a diagram illustrating a calculation example of a slip direction by the pressure sensor according to the first embodiment. FIG. 4 is a diagram illustrating a schematic configuration of a detection apparatus according to a second embodiment. FIG. 10 is a diagram illustrating a coordinate system of a unit detection area according to the second embodiment. The figure which shows schematic structure of the 1st board | substrate concerning the modification 1. FIG. The schematic diagram which shows schematic structure of a mobile telephone. The schematic diagram which shows schematic structure of a portable information terminal. The schematic diagram which shows schematic structure of a robot hand.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. Such an embodiment shows one aspect of the present invention, and does not limit the present invention, and can be arbitrarily changed within the scope of the technical idea of the present invention. In the following drawings, the scale of each layer and each member is made different from the actual scale in order to make each configuration easy to understand. In the following description, the XYZ rectangular coordinate system shown in FIG. 1 is set, and each member will be described with reference to this XYZ rectangular coordinate system. In the XYZ orthogonal coordinate system, the X axis and the Y axis are set in a direction parallel to the first substrate 10 in the state where no external force is applied, and the XY plane (z = 0) is set as the detection surface (FIG. ) Of the first substrate body 11). Further, the Z axis is set in a direction perpendicular to the first substrate 10 (normal direction of the detection surface). When an external force is applied to the detection surface, the first substrate 10 is displaced or deformed, but the XYZ orthogonal coordinate system is not changed from the direction described here and is unchanged.

(Embodiment 1)
1A and 1B are diagrams illustrating a schematic configuration of a detection apparatus according to Embodiment 1, in which FIG. 1A is a cross-sectional view and FIG. 1B is a plan view. The detection device 1 detects an external force and includes a first substrate 10, a second substrate 20, and an elastic body 30, as shown in FIG. As described above, the surface of the first substrate 10 serves as a detection surface, and the external force acting on the detection surface is detected by the detection device 1. In both the first substrate 10 and the second substrate 20, one surface of the substrate is referred to as a front surface, and the other surface opposite to the front surface is referred to as a back surface. In this specification, the direction facing the positive direction of the Z axis (upward in FIG. 1A) is referred to as the front surface, and the direction facing the negative direction of the Z axis (downward in FIG. 1A) is the back surface. Called.

  A reference point P is defined on the first substrate 10, and a plurality of pressure sensors 12 are arranged around the reference point P. The first substrate 10 includes a first substrate body 11 and a pressure sensor 12, and the pressure sensor 12 is formed in a thin film shape or a thin plate shape and is provided on the back surface of the first substrate body 11. On the other hand, the second substrate 20 includes a second substrate body 21 and a protrusion 22, and the protrusion 22 is provided on the surface of the second substrate body 21. The protrusion 22 has the largest width (or diameter when the protrusion shape is circular in plan view) on the surface (bottom) of the second substrate body 21, and the width becomes narrower toward the tip. The tangent plane of the protrusion 22 at the distal end is substantially parallel to the first substrate 10, and the distal end of the protrusion 22 is in contact with the pressure sensor 12. The center of gravity G of the protrusion 22 overlaps the reference point P. That is, the (X, Y) coordinates of the center of gravity G and the (X, Y) coordinates of the reference point P are substantially equal. In other words, the reference point P is a place that coincides with the center of the protrusion 22 when the first substrate 10 is not deformed or displaced. The 1st board | substrate 10 and the 2nd board | substrate 20 are couple | bonded via the elastic body 30 arrange | positioned at the outer peripheral part of both board | substrates.

  As shown in FIG. 1B, the detection apparatus 1 is provided with one or more protrusions 22, and a unit detection region S is determined corresponding to each protrusion 22. Although the number of unit detection regions S provided in one detection device 1 may be one, the sensitivity of detecting the magnitude and direction of the external force is improved by providing a plurality of unit detection regions S. In the present embodiment, four projections 22 are provided in one detection device 1, and four unit detection regions S exist. Note that it is only necessary that one protrusion 22 corresponds to one unit detection region S, and the number of protrusions 22 provided in one detection device 1 may be different from the number of unit detection regions S. That is, the number of protrusions 22 provided in one detection device 1 may be larger than the number of unit detection regions S.

  A center of gravity G is determined at the center of the unit detection region S, and a reference point P is determined so as to coincide with the center of gravity G in a plan view when no external force is applied. A plurality of pressure sensors 12 are arranged around the reference point P. The number of pressure sensors 12 arranged in one unit detection region S is preferably two or more. If the number of the pressure sensors 12 is two, it is possible to detect a sliding force in a linear direction connecting the two pressure sensors 12. If the number of pressure sensors 12 is three, the sliding force can be separated into an X component and a Y component. As shown in FIG. 1B, if the number of the pressure sensors 12 is four, it is easy to separate the X component and the Y component of the sliding force. These will be described in detail later.

  A plurality of pressure sensors 12 are arranged so as to be point-symmetric with respect to the reference point P. In FIG. 1B, the pressure sensors 12 are arranged in a matrix in two directions (X direction and Y direction) orthogonal to each other. Specifically, a total of four pressure sensors 12 are arranged in two rows and two columns per unit detection area S, and the center of the four pressure sensors 12 (the center of the unit detection area S) is the reference point P. It has become. As a result, the distance from the reference point P to each pressure sensor 12 is the same for all four pressure sensors 12, so the relationship between the deformation amount of the first substrate 10 and the pressure value detected by each pressure sensor 12. However, the four pressure sensors 12 are all equal. Therefore, it becomes easy to calculate the direction and magnitude of the external force from the pressure value detected by each pressure sensor 12, and the external force can be detected efficiently. A calculation method using the detected pressure value will be described later.

  The size of the unit detection region S (size in plan view) is about 2.8 mm long × 2.8 mm wide. Further, the areas of the four pressure sensors 12 are substantially equal. The interval between adjacent pressure sensors 12 in the unit detection region S is about 0.1 mm. For this reason, noise is not applied to the pressure value detected by the adjacent pressure sensor 12 due to the influence of disturbance, static electricity, or the like.

  The second substrate 20 includes a rectangular plate-shaped second substrate main body 21 and a plurality of protrusions 22 arranged on the second substrate main body 21. The second substrate body 21 is a part that supports the entire detection apparatus 1 and is preferably formed of a strong hard body. Further, it is preferable that the protrusion 22 is also formed of a strong hard body. This is because the durability of the protrusion 22 can be increased and the product life of the detection device 1 can be extended. As the hard body used for the second substrate main body 21 and the protrusions 22, a material such as a strong plastic or metal having excellent toughness is used so that the protrusions 22 have high impact resistance and durability. In the present embodiment, an ABS resin (a copolymer synthetic resin of acrylonitrile, butadiene, and styrene) is used as a material for forming the second substrate main body 21 and the protrusions 22. It is integrally formed using. The hard body is a material that hardly deforms or displaces even when an external force is applied, which affects the detection of the external force, and is an object harder than the first substrate body 11.

  The size of the protrusions 22 can be arbitrarily set, but the plurality of protrusions 22 are arranged apart from each other. For this reason, when the first substrate 10 is displaced or deformed, the deformation in the direction parallel to the XY plane can be allowed. Here, the diameter of the base of the protrusion 22 (the diameter of the portion where the protrusion 22 contacts the second substrate 20) is about 1.8 mm. The height of the protrusion 22 (the distance in the Z direction of the protrusion 22) is about 2 mm. The spacing between adjacent protrusions 22 is about 1 mm.

  Furthermore, the detection apparatus 1 includes an arithmetic device (not shown). The arithmetic unit calculates a value of a function having the pressure value detected by each pressure sensor 12 and the position of the pressure sensor 12 with respect to the reference point P as variables, and uses the value calculated by the function. Then, a predetermined calculation is performed to specify the magnitude and direction of the external force.

  2A and 2B are diagrams illustrating a schematic configuration of a first substrate according to the first embodiment, in which FIG. 2A is a cross-sectional view and FIG. 2B is a plan view. Next, the first substrate 10 will be described with reference to FIG. As shown in FIG. 2A, the first substrate 10 includes a first substrate body 11, a counter substrate 13, and a pressure sensitive material 14. In the present embodiment, the pressure sensitive material 14 is a pressure sensitive conductive elastic body. The pressure sensitive material 14 is sandwiched between the back surface of the first substrate body 11 and the surface of the counter substrate 13, and the surface of the first substrate body 11 is a detection surface. The detection device detects a force applied to the detection surface. Further, the protrusion 22 contacts the back surface of the counter substrate 13. The first substrate 10 may have the above-described structure reversed. That is, the pressure-sensitive material 14 is sandwiched between the back surface of the counter substrate 13 and the surface of the first substrate body 11 so that the surface of the counter substrate 13 is the detection surface, and the protrusions 22 are in contact with the back surface of the first substrate body 11. It may be arranged.

  The first substrate 10 further includes a first electrode wiring 211 and a second electrode wiring 212, the first electrode wiring 211 is formed on the back surface of the first substrate body 11, and the second electrode wiring 212 is formed on the surface of the counter substrate 13. Is formed. Therefore, a pressure-sensitive conductive elastic body as the pressure-sensitive material 14 is provided between the first electrode wiring 211 and the second electrode wiring 212. The pressure sensor 12 includes a first electrode wiring 211, a second electrode wiring 212, and a pressure-sensitive material 14, and is a pressure-sensitive resistance system in this embodiment. On the other hand, in plan view, as shown in FIG. 2B, the first electrode wiring 211 and the second electrode wiring 212 are in a band shape and are arranged so as to intersect each other. A square overlap portion formed at the intersection of the first electrode wiring 211 and the second electrode wiring 212 becomes one pressure sensor 12. The pressure sensor 12 converts the external force into an electric signal when the external force is applied to the detection surface. However, the method of the pressure sensor 12 is not particularly limited, and for example, a capacitance method or the like can be used.

  Since the first substrate body 11 and the counter substrate 13 are made of a flexible material, and the pressure-sensitive material 14 is also an elastic material having flexibility, the first substrate 10 has flexibility. Various plastic films such as a polyimide film and a polyester film are used for the first substrate body 11 and the counter substrate 13. The pressure sensitive material 14 may be a dielectric material having flexibility. In this case, a dielectric material is provided between the first electrode wiring 211 and the second electrode wiring 212, and the pressure sensor 12 is electrostatically charged. It becomes a capacity method.

  In the detection device 1, electrical functional elements (pressure sensor 12) and circuits (wiring connecting the pressure sensor 12, selection circuit for the pressure sensor 12, etc.) are formed on the first substrate 10, and the second substrate 20 is rigid. Only the protrusion 22 is provided, and no functional element or the like is provided. Usually, the failure of the detection apparatus 1 occurs in such functional elements and circuits. Therefore, when the detection device 1 fails, the failure can be corrected by replacing the first substrate 10, and the detection device 1 can be repaired at a low cost.

  FIG. 3 is a diagram for explaining a method for detecting the direction and magnitude of the external force acting on the unit detection region S. FIG. 3A shows a state before an external force is applied to the surface of the first substrate 10 (when no external force is applied). FIG. 3B shows a state in which an external force F in the vertical direction (in the absence of sliding force) is applied to the surface of the first substrate 10. FIG. 3C shows a state in which an external force F in an oblique direction (with a sliding force) is applied to the surface of the first substrate 10. For ease of explanation, two pressure sensors S1 (12) and S2 (12) are drawn out of the four pressure sensors 12.

  As shown in FIG. 3A, before the external force is applied to the surface of the first substrate 10, the first substrate 10 is not deformed. Thereby, the distance between the first substrate 10 and the second substrate 20 is kept constant. At this time, the reference point P is arranged at a position overlapping the center of gravity G of the protrusion 22. The pressure value of each pressure sensor 12 at this time is stored in a memory (not shown). The direction and magnitude of the external force acting are obtained based on the pressure value of each pressure sensor 12 stored in the memory.

  As shown in FIG. 3B, when a vertical external force F is applied to the surface of the first substrate 10, the plurality of pressure sensors 12 are equally pressed against the tips of the protrusions 22, and the first substrate 10 is Deflection in the negative direction of the shaft. Therefore, the pressure value of the pressure sensor 12 at this time becomes larger than when there is no external force. However, the amount of change is almost the same for all the four pressure sensors 12.

  As shown in FIG. 3C, when an external force in an oblique direction is applied to the surface of the first substrate 10, the first substrate 10 is displaced or deformed. At this time, a large pressure value is detected from the pressure sensor 12 that is strongly pressed against the protrusion 22 as in the pressure sensor S1 (12), and conversely, the pressure is weakly pressed against the protrusion 22 as in the pressure sensor S2 (12). A small pressure value is detected from the pressure sensor 12 that is pressed or not pressed. That is, different pressure values are detected by the pressure sensors 12 due to the displacement and deformation of the first substrate 10. And the magnitude | size and direction of external force are calculated | required based on the calculation method mentioned later.

  FIG. 4 is a diagram illustrating a coordinate system of the unit detection area S according to the first embodiment. FIG. 5 is a diagram illustrating a vertical pressure distribution by the pressure sensor according to the first embodiment. FIG. 6 is a diagram illustrating a calculation example of the slip direction by the pressure sensor according to the first embodiment. Next, a calculation method for obtaining the magnitude and direction of the external force from the pressure value measured by each pressure sensor 12 will be described.

In order to obtain the magnitude and direction of the external force F, a value of a function having the pressure value detected by one pressure sensor 12 and the position of the pressure sensor 12 with respect to the reference point P as variables is calculated and obtained. A predetermined calculation is performed using the obtained value. As shown in FIG. 4, a plurality of pressure sensors S1 (12) to S4 (12) are arranged in a total of four in a row of two rows and two columns per unit detection region S. Here, when the pressure values (detected values) detected by the pressure sensors S1 (12) to S4 (12) are P _S1 , P _S2 , P _S3 , and P _S4 , respectively, and the area of each pressure sensor 12 is A, The X direction component Fx of the external force (a component force acting in the X direction among the in-plane direction components of the external force) is expressed by the following equation (1).

  Further, the Y direction component Fy of the external force (the component force acting in the Y direction among the in-plane direction components of the external force) is expressed by the following equation (2).

  Note that f in the equations (1) and (2) is a proportionality constant inherent to the detection device 1 and has a unit of force. The Z direction component Fz of the external force (vertical direction component of the external force) is expressed by the following formula (3).

  In this embodiment, when detecting the component of the external force, the equation (3) is used for the normal component Fz, and the equations (1) and (2) are used for the sliding force. The following steps are taken for the sliding force. First, a first axis (for example, X axis) and a second axis (for example, Y axis) are defined on the detection surface. In order to detect the component of the sliding force along the first axis, the pressure sensor 12 (positioned in the positive direction of the first axis from the reference point P as a function having the pressure value and the position of the pressure sensor 12 as variables). For example, for S2 (12) and S4 (12), +1 is multiplied by the detected pressure value and pressure sensor 12 (eg, S1 (12) and S3 (12)) located in the negative direction of the first axis. Is multiplied by the detected pressure value and the sum of these values is taken. Next, a predetermined calculation is performed using the obtained numerical value (referred to as a uniaxial difference) to obtain a component of the sliding force along the first axis. Similarly, in order to detect the component of the sliding force along the second axis, with respect to the pressure sensor 12 (for example, S1 (12) and S2 (12)) positioned in the positive direction of the second axis from the reference point P, +1 is multiplied by the detected pressure value, and for the pressure sensor 12 (eg, S3 (12) and S4 (12)) located in the negative direction of the second axis, -1 is multiplied by the detected pressure value, The sum of these shall be taken. Next, the component of the sliding force along the second axis is obtained by performing a predetermined calculation using the obtained numerical value (referred to as a biaxial difference). As an example of the predetermined calculation, the previous numerical value (uniaxial difference or biaxial difference) is divided by the sum of the pressure values detected by all the pressure sensors 12 (for example, S1 (12) to S4 (12)). Then, a proportional constant f unique to the detection apparatus 1 is multiplied.

  As shown in the equation (1), in the X direction component Fx of the external force, the pressure sensor S2 (12 arranged in the + X direction among the pressure values detected by the four pressure sensors S1 (12) to S4 (12). ) And S4 (12) are combined, and the values detected by the pressure sensors S1 (12) and S3 (12) arranged in the −X direction are combined. As described above, the pressure value obtained by combining the pressure sensors S2 (12) and S4 (12) arranged in the + X direction and the pressure value obtained by combining the pressure sensors S1 (12) and S3 (12) arranged in the -X direction. The X-direction component of the external force is obtained based on the difference between.

  As shown in Expression (2), in the Y direction component Fy of the external force, the pressure sensor S1 (12) arranged in the + Y direction among the pressure values detected by the four pressure sensors S1 (12) to S4 (12). ) And S2 (12) are combined, and the values detected by the pressure sensors S3 (12) and S4 (12) arranged in the -Y direction are combined. As described above, the pressure value obtained by combining the pressure sensors S1 (12) and S2 (12) arranged in the + Y direction and the pressure value obtained by combining the pressure sensors S3 (12) and S4 (12) arranged in the -Y direction. The Y-direction component of the external force is obtained based on the difference between.

  As shown in Expression (3), the Z direction component Fz of the external force is obtained by a resultant force obtained by adding the pressure values of the four pressure sensors S1 (12) to S4 (12). However, the Z direction component Fz of the external force tends to be detected with a larger detection value than the X direction component Fx of the external force and the Y direction component Fy (component force) of the external force. For example, when a hard material is used as the material of the first substrate body 11 or the shape of the tip of the protrusion 22 is sharpened, the detection sensitivity of the Z-direction component Fz of the external force increases. Specifically, if a hard material is used as the material of the first substrate 10, the displacement or deformation of the first substrate 10 is difficult to occur, and the detected value of the external force in the in-plane direction becomes small. Further, if the shape of the tip of the protrusion 22 is sharpened, a strong sensitivity (uncomfortable feeling) may be given to the touch feeling when the contact surface is touched with a finger. For this reason, in order to align the detection value of the Z direction component Fz of the external force with the sensitivity of the detection value of the X direction component Fx of the external force and the Y direction component Fy of the external force, each constituent substrate used for the first substrate 10 It is necessary to appropriately correct the detection value with a correction coefficient determined by the material, the protrusion 22 and the shape. Actually, a proportionality constant f unique to the detection apparatus 1 is determined so as to correct such an influence correctly.

  FIG. 5 shows an example in which the detection devices 1 are arranged in a matrix of 15 rows and 15 columns (total of 225) to form a touch pad. Each detection device 1 has pressure sensors S1 (12) to S4 (in the unit detection region S). 12) are arranged in a total of four in two rows and two columns. In FIG. 5, the position on the upper left side of the center of the detection surface of the touchpad is pushed diagonally with a finger. At this time, the pressure in the vertical direction of the external force is greatest at the center of the portion where the external force is applied (the output voltage of the pressure sensor 12 is about 90 to 120 mV). Further, the vertical pressure of the external force decreases in the order of the peripheral portion (about 60 to 90 mV) and the outermost peripheral portion (about 30 to 60 mV) next to the central portion. Moreover, the output voltage of the pressure sensor 12 is about 0 to 30 mV in the region not pressed by the finger.

  Consider a method for calculating the in-plane direction component (sliding direction) of the external force when the upper left position of the touch pad detection surface shown in FIG. FIG. 6 shows an example of calculating the external force. In the example of FIG. 6, the pressing force (external force) of the finger acts on a portion arranged in 3 rows × 3 columns in the detection device 1 arranged in 15 rows × 15 columns. The pressure in the vertical direction of the external force is the largest (110 mV) at the center of 3 rows and 3 columns where the external force is applied, as in FIG. Each detection device 1 has four pressure sensors S1 (12) to S4 (12), respectively, and the sum of outputs from the four pressure sensors S1 (12) to S4 (12) is a normal component of the external force. (Equation (3) above). For example, the sum from the pressure sensors 12 is 54 mV + 28 mV + 18 mV + 10 mV = 110 mV in the detection device 1 at the center.

  On the other hand, the difference between the pressure values detected by the pressure sensors 12 arbitrarily combined among the pressure values detected by the pressure sensors S1 (12) to S4 (12) is calculated, and the external force is calculated based on the difference. The applied direction (the direction of the sliding force) is calculated. That is, in each detection device 1, the X-direction component Fx of the external force and the Y-direction component Fy of the external force are calculated based on the above formulas (1) and (2). For example, in the detection device 1 at the center, Fx = (28 + 10−54−18) /110f=−0.31f and Fy = (54 + 28−18−10) /110f=0.49f. Therefore, tan θ = −0.49 / 0.31 = −1.58, and the direction of the sliding force is θ = 122 °. Thus, when taking the average of the direction of the sliding force detected by the nine detection devices 1, it can be seen that an external force acts in a direction of about 123 ° counterclockwise with respect to the + X direction. In calculating the direction in which the external force acts, in addition to the method of obtaining the average value of the results calculated from the plurality of detection devices 1 as performed here, for example, calculation from the plurality of detection devices 1 is performed. It is possible to use a method that employs the maximum value of the obtained results, a method that employs a detection value larger than a predetermined threshold, or the like.

  According to the detection device 1 of the present embodiment, the first substrate 10 in contact with the protrusion 22 can be displaced or deformed according to the external force F. Therefore, the detection in Patent Document 1 and Patent Document 2 is possible. Compared with the device, the detection accuracy of the magnitude and direction of the external force can be increased. Specifically, a strong pressure value is detected by the pressure sensor 12 in which the protrusion 22 is present in the direction in which the external force is applied, and a weak pressure value is detected in the pressure sensor 12 in which the protrusion 22 is not present in the direction in which the external force is applied. As a result, different pressure values are detected by each pressure sensor 12, and the magnitude and direction of the external force including the sliding force can be measured with high accuracy from these detected values. Further, since an external force is applied from one surface forming the first substrate 10, the second substrate 20 having the protrusions 22 can be fixed. Furthermore, since the projection is made of a hard rigid body, the measurement accuracy is improved, the possibility of the projection being damaged during the use of the detection device can be reduced, and the durability of the detection device can be improved and its life can be extended. it can.

  Further, since the plurality of pressure sensors 12 are arranged symmetrically with respect to the reference point P, the distances between the reference point P and each pressure sensor 12 are equal to each other. For this reason, it becomes easy to calculate the direction and magnitude of the external force from the position and pressure value of each of the pressure sensors S1 (12) to S4 (12), and the external force can be detected efficiently.

  Since the plurality of pressure sensors 12 are arranged in a matrix in two directions orthogonal to each other, the direction and magnitude of the external force are calculated from the pressure values detected by the pressure sensors S1 (12) to S4 (12). It becomes easy to do. In other words, the external force can be detected efficiently.

  Further, since the plurality of protrusions 22 are arranged apart from each other, it is possible to allow deformation in a direction parallel to the detection surface when the first substrate 10 is displaced or deformed. As a result, the direction and magnitude of the external force can be detected with high accuracy.

(Embodiment 2)
7A and 7B are diagrams illustrating a schematic configuration of a detection apparatus according to the second embodiment, in which FIG. 7A is a cross-sectional view and FIG. 7B is a plan view. Hereinafter, the detection apparatus 2 according to the present embodiment will be described. In addition, about the component same as Embodiment 1, the same code | symbol is attached | subjected and the overlapping description is abbreviate | omitted.

  The detection device 2 of the present embodiment is different from the detection device 1 described in the above-described first embodiment in that a plurality of pressure sensors 12 are arranged in at least four rows and four columns in two directions orthogonal to each other. In FIG. 7, for the sake of convenience, a plurality of pressure sensors 12 are arranged in four rows and four columns per unit detection area S. Actually, as shown in FIG. The area S may be arranged in four rows and four columns or more.

  As shown in FIG. 7A, the detection device 2 includes a first substrate 10 having a plurality of pressure sensors 12 arranged around the reference point P, and a protrusion whose tip is in contact with the first substrate 10. And a second substrate 20 having 22 formed thereon. Further, as shown in FIG. 7B, a plurality of pressure sensors 12 are arranged in a total of 16 in 4 rows and 4 columns in two directions (X direction and Y direction) orthogonal to each other. The center of these 16 pressure sensors 12 (the center of the unit detection region S) is a reference point P, and the (X, Y) coordinates of the reference point P substantially coincide with the (X, Y) coordinates of the center of gravity G. ing.

  FIG. 8 is a diagram illustrating a coordinate system of the unit detection region S according to the second embodiment corresponding to FIG. In FIG. 8, a plurality of pressure sensors Si (12) (100) are arranged in a matrix, and 25 of these pressure sensors Si (12) are partitioned in the −X direction and the + Y direction, respectively. It is arranged in a region, a region partitioned in the + X direction and the + Y direction, a region partitioned in the −X direction and the −Y direction, and a region partitioned in the + X direction and the −Y direction. Further, in FIG. 8, for convenience, 100 pressure sensors Si (12) are illustrated, but the number of pressure sensors Si (12) is not limited to this and can be arbitrarily changed.

  As shown in FIG. 8, a plurality of pressure sensors Si (12) are arranged in a total of 100 per unit detection area S in 10 rows and 10 columns. Here, the pressure value (detection value) detected by each pressure sensor Si (12) is Pi (i = 1 to 100), and the in-plane direction of the distance between the reference point P and each pressure sensor Si (12) Let the component be ri (i = 1 to 100). Further, when the X direction component of the in-plane direction component is rxi (i = 1 to 100) and the Y direction component of the in-plane direction component is ryi (i = 1 to 100), the X direction component Fx (external force) of the external force Of the in-plane direction component) is expressed by the following formula (4).

  Further, the Y direction component Fy of the external force (a component force acting in the Y direction among the in-plane direction components of the external force) is expressed by the following equation (5).

  In the equations (4) and (5), g is a proportionality constant inherent to the detection device 2 and has a unit of force / length. Further, the Z direction component Fz of the external force (vertical direction component of the external force) is expressed by the following formula (6). A in Expression (6) is the area of one pressure sensor 12.

  In this embodiment, when detecting the component of the external force, the equation (6) is used for the normal component Fz, and the equations (4) and (5) are used for the sliding force. The following steps are taken to detect slip force. First, a first axis (for example, X axis) and a second axis (for example, Y axis) are defined on the detection surface. In order to detect the component of the sliding force along the first axis, the pressure value detected by each pressure sensor 12 is weighted by the first axis component of the distance, and these weighted pressure values (referred to as first moments). It is obtained by performing a predetermined calculation using the sum of. Similarly, in order to detect the component of the sliding force along the second axis, the pressure value detected by each pressure sensor 12 is weighted by the second axis component of the distance, and these weighted pressure values (second moments) are detected. It is obtained by performing a predetermined calculation using the sum of As an example of the predetermined calculation, the sum of the weighted pressure values (the sum of the first moments and the sum of the second moments) is divided by the sum of the pressure values detected by all the pressure sensors 12 and detected. Multiply by a proportionality constant g specific to the device 2.

  As shown in the equation (4), in order to obtain the X-direction component Fx of the external force with the first axis as the X axis, 100 pressure values detected by the 100 pressure sensors Si (12) are used. One moment is obtained and summed, and this sum is divided by the sum of the pressure values detected by all the pressure sensors 12 and multiplied by a proportional constant g unique to the detection device 2.

  Similarly, as shown in Expression (5), in order to obtain the Y-direction component Fy of the external force with the second axis as the Y-axis, 100 pressure sensors Si (12) are used to calculate the 100th The two moments are obtained and summed, and the sum is divided by the sum of the pressure values detected by all the pressure sensors 12 and multiplied by a proportional constant g unique to the detection device 2.

  As shown in the equation (6), in order to obtain the Z direction component Fz of the external force, the pressure values detected by the 100 pressure sensors Si (12) are added, and the area A of one pressure sensor 12 is added thereto. Take a ride. However, the detected value of the Z direction component Fz of the external force tends to be detected larger than the X direction component Fx of the external force and the Y direction component Fy of the external force. For this reason, in order to align the detected value of the Z direction component Fz of the external force with the sensitivity of the detected values of the X direction component Fx of the external force and the Y direction component Fy of the external force, it is determined by the material of the first substrate 10, the protrusion 22 and the shape. It is necessary to appropriately correct the detected value with the correction coefficient. Specifically, a proportionality constant g unique to the detection apparatus 2 is determined so as to correct such an influence correctly.

  According to the detection device 2 of the present embodiment, since the plurality of pressure sensors 12 are arranged in at least 4 rows and 4 columns in two directions orthogonal to each other, the number of pressure sensors 12 to be arranged increases. For this reason, based on the pressure values detected by the large number of pressure sensors 12, the direction and magnitude of the external force can be obtained more accurately.

  The present invention is not limited to the above-described embodiment, and various changes and improvements can be added to the above-described embodiment. A modification will be described below.

(Modification 1)
FIG. 9 is a diagram illustrating a schematic configuration of a first substrate according to the first modification, where (a) is a cross-sectional view and (b) is a plan view. Next, with reference to FIG. 9, the 1st board | substrate 10 concerning the modification 1 is demonstrated. In the first embodiment shown in FIG. 2, the counter substrate 13 is provided. However, this is not essential, and the counter substrate 13 is omitted in this modification. As shown in FIG. 9A, the first substrate 10 includes a first substrate body 11 and a pressure sensitive material 14. The pressure sensitive material 14 is bonded to the back surface of the first substrate body 11, and the surface of the first substrate body 11 is a detection surface. The protrusion 22 directly contacts the pressure sensitive material 14. As in the first embodiment, the first substrate body 11 and the pressure-sensitive material 14 are flexible materials, so the first substrate 10 has flexibility. The first substrate 10 may have the above-described structure reversed. That is, the pressure-sensitive material 14 may be adhered to the surface of the first substrate body 11, the surface of the pressure-sensitive material 14 may be used as a detection surface, and the protrusion 22 may be in contact with the back surface of the first substrate body 11.

  The first substrate 10 includes a first electrode wiring 211 and a second electrode wiring 212, and both the first electrode wiring 211 and the second electrode wiring 212 are formed on the back surface of the first substrate body 11. Therefore, the electrical characteristics of the pressure-sensitive material 14 in the horizontal direction (direction parallel to the XY plane) of the first substrate 10 are detected. On the other hand, in the plan view, as shown in FIG. 9B, the first electrode wiring 211 and the second electrode wiring 212 are strip-shaped and arranged so as to be substantially parallel. A square sandwiched between the first electrode wiring 211 and the second electrode wiring 212 is one pressure sensor 12. In this modification, a pressure-sensitive conductive elastic body is used as the pressure-sensitive material 14, so the pressure sensor 12 measures the horizontal electric resistance R. However, the method of the pressure sensor 12 is not particularly limited, and for example, a capacitance method or the like can be used. In order to increase the detection sensitivity, it is preferable that the adjacent pressure sensors 12 are arranged so that electrode wirings having the same polarity are adjacent to each other. That is, since both the first electrode wiring 211 and the second electrode wiring 212 are parallel to the Y-axis, the first electrode wiring 211 is on the right side (X-axis of the pressure sensor 12 in the pressure sensors S1 (12) and S3 (12). The second electrode wiring 212 is provided on the left side (the negative side of the X axis). On the other hand, in the pressure sensors S2 (12) and S4 (12), the first electrode wiring 211 is provided on the left side (negative side of the X axis) in the pressure sensor 12, and the second electrode wiring 212 is on the right side. (On the positive side of the X axis). When the number of pressure sensors 12 increases, the wiring connecting the first electrode wiring 211 or the second electrode wiring 212 and an external arithmetic unit is connected to the gap between the pressure sensors 12 or the outer periphery of the first substrate body 11. Can be provided in the part.

  As shown in this modification, the counter substrate 13 can be omitted, so that the first substrate 10 can be easily manufactured.

(Electronics)
The detection devices 1 and 2 are used as a touch pad or the like that detects the magnitude and direction of an external force applied to the detection surface, and are used as a pointing device instead of a mouse in an electronic device such as a notebook computer. At this time, it is preferable that the electronic device includes a housing, and the second substrate 20 forms a part of the housing. That is, the housing may also serve as the second substrate body 21, and the protrusion 22 may be provided directly on the housing. This is because the repair can be easily completed by replacing the first substrate 10 when the detection devices 1 and 2 fail.

  FIG. 10 is a schematic diagram showing a schematic configuration of a mobile phone to which the detection devices 1 and 2 according to the embodiment or the detection devices 1 and 2 using the first substrate 10 described in the modification are applied. is there. The cellular phone 1000 includes a plurality of operation buttons 1003, a scroll device 1002, and a liquid crystal panel 1001 as a display unit. The detection device 1 is used in a planar scroll device 1002, and the screen displayed on the liquid crystal panel 1001 is scrolled by operating the scroll device 1002. A menu icon (not shown) is displayed on the liquid crystal panel 1001. For example, when the scroll device 1002 is operated to select a phone book menu icon, the phone book is displayed on the liquid crystal panel 1001.

  FIG. 11 shows a personal digital assistant (PDA) to which the detection devices 1 and 2 according to the above embodiment or the detection devices 1 and 2 using the first substrate 10 described in the modification are applied. It is a schematic diagram which shows schematic structure of these. The portable information terminal 2000 includes a plurality of operation buttons 2002, a touch pad 2003, and a liquid crystal panel 2001 as a display unit. The detection device 1 is used for a touch pad 2003, and by operating the touch pad 2003, a pointer displayed on the liquid crystal panel 1001 is moved or a menu is selected. For example, the address book is displayed by moving the pointer to the address book menu icon (not shown) via the touch pad 2003 and performing a selection operation there.

  According to such an electronic device, since the above-described detection devices 1 and 2 are provided, an electronic device that detects the direction and magnitude of the external force with high accuracy can be provided. In addition, when the detection devices 1 and 2 are out of order, repair can be easily performed.

  Other electronic devices include personal computers, video camera monitors, car navigation devices, pagers, electronic notebooks, calculators, word processors, workstations, videophones, POS terminals, digital still cameras, and touch panels. Equipment and the like. The detection devices 1 and 2 according to the present invention can also be applied to these electronic devices.

(robot)
FIG. 12 is a schematic diagram illustrating a schematic configuration of a robot to which the detection devices 1 and 2 according to the above embodiment or the detection devices 1 and 2 using the first substrate 10 described in the modification are applied. . As shown in FIG. 12A, the robot 3000 includes a main body 3003, a pair of arms 3002, and a grip 3001 to which the detection devices 1 and 2 are applied. For example, when a drive signal is transmitted to the arm unit 3002 by a control device such as a remote controller, the pair of arm units 3002 open and close. Here, the second substrate 20 may form a part of the grip portion 3001. That is, the grip portion 3001 may also be used as the second substrate body 21, and the protrusion 22 may be provided directly on the grip portion 3001. This is because the repair can be easily completed by replacing the first substrate 10 when the detection devices 1 and 2 fail.

  As shown in FIG. 12B, consider a case where the robot 3000 holds an object 3010 such as a cup. At this time, the gripping force acting on the object 3010 is detected as a pressure by the gripping unit 3001. Since the robot 3000 includes the detection devices 1 and 2 described above as the gripping unit 3001, a force (sliding force) in a direction sliding with gravity Mg in addition to a force perpendicular to the surface (contact surface) of the object 3010. Can be detected. For example, the object 3010 can be gripped with increasing or decreasing force so as not to deform a soft object or drop a slippery object.

  According to this robot, since the above-described detection devices 1 and 2 are provided, it is possible to provide a robot capable of detecting the direction and magnitude of the gripping force with high accuracy.

  DESCRIPTION OF SYMBOLS 1 ... Detection apparatus, 2 ... Detection apparatus, 10 ... 1st board | substrate, 11 ... 1st board | substrate body, 12 ... Pressure sensor, 13 ... Opposite board | substrate, 14 ... Pressure sensitive material, 20 ... 2nd board | substrate, 21 ... 2nd board | substrate Main body, 22 ... projection, 30 ... elastic body, 211 ... first electrode wiring, 212 ... second electrode wiring, 1000 ... mobile phone, 1002 ... scroll device, 2000 ... mobile information terminal, 2003 ... touch pad, 3000 ... robot, 3001 ... Grasping part, 3010 ... Object.

Claims (13)

A detection device for detecting an external force,
A first substrate having a plurality of pressure sensors arranged around a reference point;
A second substrate having a protrusion,
The first substrate has flexibility;
The detection device, wherein the protrusion is arranged such that a center of gravity is located at a position overlapping with the reference point, and a tip portion is in contact with the pressure sensor.   The detection apparatus according to claim 1, wherein the surface on which the external force acts is provided on the first substrate.   The detection device according to claim 1, wherein the protrusion is formed of a hard body.   4. The detection apparatus according to claim 1, wherein the first substrate and the second substrate are connected via an elastic body. 5.   The detection device according to claim 1, wherein the pressure sensor is arranged point-symmetrically with respect to the reference point.   The detection device according to claim 5, wherein the pressure sensors are arranged in a matrix in two directions orthogonal to each other.   The detection device according to claim 6, wherein the pressure sensors are arranged in at least 4 rows and 4 columns in two directions orthogonal to each other. A plurality of the protrusions are formed on the second substrate;
The detection device according to claim 1, wherein the protrusions are arranged apart from each other. Calculating a value of a function having the pressure value detected by the pressure sensor and the position of the pressure sensor with respect to the reference point as variables;
The detection device according to claim 1, further comprising an arithmetic device that performs a predetermined operation using the value.   An electronic apparatus comprising the detection device according to claim 1.   The electronic apparatus according to claim 10, further comprising a housing, wherein the second substrate forms a part of the housing.   A robot comprising the detection device according to claim 1.   The robot according to claim 12, further comprising a grip part, wherein the second substrate forms a part of the grip part.

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