Reaction force generator

Abstract

A reaction force generator (1) comprises a rotor (2) that can rotate around a first rotation axis (x1) and can move around a second rotation axis (x2) orthogonal to or intersecting the first rotation axis (x1). A reaction force is generated around a reaction force axis (A3) orthogonal to or intersecting the first rotation axis (x1) and the second rotation axis (x2) by the rotor (2) that rotates around the first rotation axis (x1) and moves around the second rotation axis (x2) through a predetermined angle. The reaction force axis (A3) is moved around the second rotation axis (x2) by the rotor (2) that moves around the second rotation axis (x2) through the predetermined angle.

Description

Reaction force generator

[0001] The present invention relates to a reaction force generating device.

[0002] For example, Patent Document 1 discloses a device that generates a rotational reaction force using a gyroscope and generates the reaction force by controlling the attitude and rotation speed of the gyroscope.

[0003] WO 2002 / 073385

[0004] In one example of a device, a reaction force is generated by a rotational shaft rotating around one axis and rotating around two axes, and it is desirable to be able to control the generation of this reaction force.

[0005] The present invention has been made in view of the above-mentioned problems, and an example of an object of the present invention is to provide a reaction force generating device that can control the generation of a reaction force.

[0006] A reaction force generating device according to one aspect of the present invention comprises a rotor that is rotatable around a first rotation axis and movable around a second rotation axis that is perpendicular to or intersects the first rotation axis, and the rotor that rotates around the first rotation axis and moves around the second rotation axis through a predetermined angle generates a reaction force around a reaction axis that is perpendicular to or intersects the first rotation axis and the second rotation axis, and the rotor that moves around the second rotation axis through the predetermined angle moves the reaction force axis around the second rotation axis.

[0007] FIG. 1 is a schematic diagram for explaining the principle of a reaction force generator according to an embodiment of the present invention. FIG. 1 is a schematic diagram of an analysis model 10 showing the generation of a reaction force. FIG. 2 is a schematic diagram of an analysis model 10 showing the generation of a reaction force. FIG. 3 is a schematic diagram of an analysis model 10 showing the generation of a reaction force. FIG. 4 is a schematic diagram of an analysis model 10 showing the generation of a reaction force. FIG. 5 is a schematic diagram of an analysis model 10 showing the generation of a reaction force. FIG. 6 is a graph showing changes in torque at each angular position around a second rotation axis x2. FIG. 7 is a partial perspective perspective view showing an outline of the structure of a reaction force generator 1 that executes the operation of the analysis model 10. FIG. 8 is a schematic diagram for explaining a first specific example of controlling the generation of a reaction force RF. FIG. 9 is a schematic diagram for explaining a second specific example of controlling the generation of a reaction force RF.

[0008] An embodiment of the present invention will now be described with reference to the accompanying drawings. The inventors have developed a reaction force generator capable of controlling the generation of a reaction force utilizing the so-called gyroscopic effect. Specifically, the developed reaction force generator has been confirmed to be capable of controlling the generation of a reaction force utilizing the so-called gyroscopic effect based on verification including at least an analytical simulation using, for example, structural analysis software and confirmation of operation using an actually assembled device. Furthermore, it has been confirmed that this reaction force generator can output a variety of sensations and the like by generating reaction forces in various patterns based on the control of the generation of the reaction force.

[0009] FIG. 1 is a schematic diagram illustrating the principle of a reaction force generator according to one embodiment of the present invention. Specifically, FIG. 1 is a perspective view showing an example of an analytical model 10 established on structural analysis software. The analytical model 10, for example, includes a rotor 11, a first frame 12 supporting the rotor 11 so as to be rotatable about a first rotation axis x1, and a second frame 13 supporting the first frame 12 so as to be movable about a second rotation axis x2. In the space in which the analytical model 10 is disposed, the second frame 13 is stationary; that is, the position of the second frame 13 is assumed to be constant. In other words, the second frame 13 may be fixed to an object, or the second frame 13 may be held in a predetermined position by a human hand or the like.

[0010] In the space in which the analytical model 10 is placed, an x-axis, a y-axis, and a z-axis are defined, each of which is perpendicular to the other. For ease of explanation, the z-axis direction defines up and down, and the y-axis direction defines left and right. In the analytical model 10 of FIG. 1 , the first rotation axis x1 is defined parallel to the y-axis. The second rotation axis x2 is defined parallel to the x-axis and perpendicular to (intersects with) the first rotation axis x1. Since the second rotation axis x2 is defined relative to the second frame 13, in the space in which the analytical model 10 is placed, the position of the second rotation axis x2 remains unchanged as long as the position of the second frame 13 remains unchanged. However, as will be described later, the first rotation axis x1 can move around the second rotation axis x2.

[0011] In one example, the rotor 11 includes a weight 111 and a shaft 112 extending from the weight 111 along the first rotation axis x1. The weight 111 is a weight having a predetermined mass. The shaft 112 extends in opposite directions along the first rotation axis x1 from a first surface 111a and a second surface 111b of the weight 111, which are opposite to each other. In the orientation shown in FIG. 1 , the first surface 111a faces to the right in the y-axis direction, and the second surface 111b faces to the left in the y-axis direction. The first frame 12 is, for example, a frame formed in an annular shape (in this example, having a square outline) when viewed in a plan view along the z-axis in FIG. 1 . The first frame 12 supports both ends of the shaft 112 of the rotor 11 so as to be rotatable around the first rotation axis x1.

[0012] The second frame 13 includes a vertical frame 13A that is generally annular (in this example, has a square outline) when viewed in a plane along the x-axis, and a horizontal frame 13B that is generally annular (in this example, has a square outline) when viewed in a plane along the z-axis. The vertical frame 13A extends along the yz plane, and the horizontal frame 13B extends along the xy plane. The vertical frame 13A and the horizontal frame 13B are connected to each other so that they intersect at right angles. The rotor 11 and the first frame 12 are housed within the second frame 13. The first frame 12 is supported by the horizontal frame 13B so as to be movable around the second rotation axis x2.

[0013] The second frame 13 is defined with a first axis A1 that is parallel to the z-axis and passes through the vertical frame 13A, and a second axis A2 that is parallel to the y-axis and passes through the horizontal frame 13B. In this example, the first axis A1 is defined at a midpoint of the vertical frame 13A in the y-axis direction, and the second axis A2 is defined at a midpoint of the horizontal frame 13B in the x-axis direction. The first axis A1 is perpendicular to (intersects with) the second axis A2. Furthermore, the first axis A1 and the second axis A2 are perpendicular to (intersect with) the second rotation axis x2 at the orthogonal (intersecting) position of the first rotation axis x1 and the second rotation axis x2. At the position of the rotor 11 shown in FIG. 1 , the first rotation axis x1 coincides with the second axis A2. Furthermore, as the first rotation axis x1 moves around the second rotation axis x2, the first rotation axis x1 can also coincide with the first axis A1.

[0014] As described above, the rotor 11 is supported by the first frame 12 so as to be rotatable around the first rotation axis x1. The first frame 12 is supported by the horizontal frame 13B of the second frame 13 so as to be movable around the second rotation axis x2, which is perpendicular to (intersects) the first rotation axis x1. As will be described later, the inventors have confirmed through testing that when the rotor 11 rotates around the first rotation axis x1 (axis 1) and moves around the second rotation axis x2 (axis 1), a reaction force is generated due to the so-called gyro effect. Furthermore, the inventors have confirmed through testing that reaction forces can be generated in various patterns by controlling the movement of the rotor 11 around the second rotation axis x2 while rotating around the first rotation axis x1.

[0015] Next, the results of verification of how a reaction force is generated using the analytical model 10 will be described below. For the verification, the inventors performed an analytical simulation using structural analysis software. For example, in the analytical model 10 shown in FIG. 1 , the shaft 112 of the rotor 11, i.e., the first rotation axis x1, coincides with the second axis A2. The position of this first rotation axis x1 is defined as an angle of 0 degrees around the second rotation axis x2. While the rotor 11 rotates at a predetermined rotation speed around the first rotation axis x1, when the rotor 11 moves at a predetermined speed around the second rotation axis x2, a reaction force is generated in a predetermined direction due to the so-called gyroscopic effect. The following description will explain how the reaction force is generated with respect to the second frame 13 (particularly the vertical frame 13A), which is fixed (stationary) in this three-dimensional space.

[0016] 2 to 7 are schematic diagrams of an analytical model 10 illustrating the generation of a reaction force. In FIGS. 2 to 7, the rotor 11 is assumed to rotate around the first rotation axis x1 at a predetermined speed, for example, clockwise. In this example, the direction of rotation of the rotor 11 around the first rotation axis x1 is defined as a direction viewed from one direction in the y-axis direction. In this example, the direction of rotation is defined as a direction viewed from the right to the left in the y-axis direction in FIG. 1. While the rotor 11 rotates around the first rotation axis x1, the rotor 11, i.e., the first rotation axis x1, moves from the angle (0 degrees) position in FIG. 1 to the angle positions shown in each figure. In other words, the first rotation axis x1 moves from the angle (0 degrees) position around the second rotation axis x2 to each predetermined angle position.

[0017] As shown in FIG. 2 , when the first rotation axis x1 moves to a position of a predetermined angle (45 degrees) around the second rotation axis x2, a clockwise force f1 is generated around the first axis A1 and a clockwise force f2 is generated around the second axis A2 on the second frame 13. The direction of force f1 is determined by the direction viewed from top to bottom in the z-axis direction. On the other hand, the direction of force f2 is determined by the direction viewed from right to left in the y-axis direction. As a result of the generation of these forces f1 and f2, a reaction force RF is generated on the second frame 13 as a whole around a reaction axis A3 that passes through the rotor 11. In this example, the reaction axis A3 is an axis that passes through the intersection of the first axis A1 and the second axis A2 and is perpendicular to the second rotation axis x2. This reaction axis A3 is always determined at a constant position relative to the rotor 11, regardless of the angular position of the rotor 11 around the second rotation axis x2.

[0018] Specifically, the reaction axis A3 intersects the first axis A1 and the second axis A2 at a 45-degree angle around the second rotation axis x2, corresponding to the 45-degree angle of the rotor 11, i.e., the first rotation axis x1, around the second rotation axis x2. In this example, the position of the angle (45 degrees) of the reaction axis A3 around the second rotation axis x2 is equidistant from the first axis A1 and the second axis A2 around the second rotation axis x2, so the magnitude of the force f1 around the first axis A1 is equal to the magnitude of the force f2 around the second axis A2. The resultant force of these forces f1 and f2 generates a reaction force RF that tends to rotate the second frame 13 as a whole clockwise around the reaction axis A3. Conceptually, reaction forces RF that tend to move the upper left corner and the lower right corner of the vertical frame 13A in opposite clockwise directions around the reaction axis A3 are generated.

[0019] Next, assume that the rotor 11 moves from the angle (0 degrees) position in FIG. 1 to the angle (90 degrees) position in FIG. 3 . In other words, assume that the first rotation axis x1 moves from an angle of 0 degrees around the second rotation axis x2 to an angle of 90 degrees. As shown in FIG. 3 , as the first rotation axis x1 moves around the second rotation axis x2, the first rotation axis x1 coincides with the first axis A1. Furthermore, the reaction force axis A3 defined by the rotor 11 coincides with the second axis A2. In other words, the reaction force axis A3 moves to an angle of 90 degrees around the second rotation axis x2. As a result, a force f3 is generated in the second frame 13 in the clockwise direction around the second axis A2. Meanwhile, no force is generated around the first axis A1. As a result, a reaction force RF is generated around the reaction force axis A3 as a whole in the second frame 13.

[0020] Specifically, the reaction axis A3 moves around the second rotation axis x2 to a position where it intersects (is perpendicular to) the first axis A1 at a 90-degree angle, corresponding to the angle of the rotor 11 around the second rotation axis x2, i.e., 90 degrees. The reaction axis A3 also coincides with the second axis A2. Furthermore, the reaction axis A3 intersects (is perpendicular to) the first rotation axis x1 and the second rotation axis x2 at a position where the first axis A1 and the second axis A2 are perpendicular to each other. As a result, a force f3 generated in the clockwise direction around the second rotation axis x2 generates a reaction force RF that tends to rotate the second frame 13 as a whole clockwise around the reaction axis A3. Conceptually, the reaction force RF tends to move the two upper left and right corners and the two lower left and right corners of the vertical frame 13A in the clockwise direction around the reaction axis A3. In addition, the components of the reaction force RF that tend to move the two upper right and lower right corners of the vertical frame 13A are equal in magnitude to the components of the reaction force RF that tend to move the two upper left and lower left corners of the vertical frame 13A.

[0021] Next, assume that the rotor 11 moves from the angle (0 degrees) position in FIG. 1 to the angle (120 degrees) position in FIG. 4 . In other words, assume that the first rotation axis x1 moves from the angle (0 degrees) position around the second rotation axis x2 to the angle (120 degrees) position. As shown in FIG. 4 , as the first rotation axis x1 moves around the second rotation axis x2, the first rotation axis x1 intersects the upper and lower portions of the vertical frame 13A, and the reaction force axis A3 intersects the left and right portions of the vertical frame 13A. As a result, a force f4 is generated in the second frame 13 in the counterclockwise direction around the first axis A1, and a force f5 is generated in the clockwise direction around the second axis A2. As a result of the generation of these forces f4 and f5, a reaction force RF is generated around the reaction force axis A3 as a whole in the second frame 13.

[0022] Specifically, the reaction axis A3 moves around the second rotation axis x2 to a position where it intersects with the first axis A1 and the second axis A2 at an angle of 120 degrees, corresponding to the angle of the rotor 11 around the second rotation axis x2, i.e., 120 degrees. In this example, the position of the reaction axis A3's angle (120 degrees) around the second rotation axis x2 is closer to the second axis A2 than to the first axis A1, so the magnitude of the force f4 around the first axis A1 is smaller than the magnitude of the force f5 around the second axis A2. As a result, the resultant force of these forces f4 and f5 generates a reaction force RF that tends to rotate the second frame 13 as a whole clockwise around the reaction axis A3. Specifically, the reaction force RF that tends to move the upper and lower portions of the vertical frame 13A in a clockwise direction around the reaction axis A3 is generated. The components of the reaction force RF that tend to move the upper right and lower left corners of the vertical frame 13A are greater than the components of the reaction force RF that tend to move the upper left and lower right corners of the vertical frame 13A.

[0023] Next, assume that the rotor 11 moves from the angle (0 degrees) position in FIG. 1 to the angle (135 degrees) position in FIG. 5 . In other words, assume that the first rotation axis x1 moves from the angle (0 degrees) position around the second rotation axis x2 to the angle (135 degrees) position. As shown in FIG. 5 , as the first rotation axis x1 moves around the second rotation axis x2, the first rotation axis x1 intersects the upper right corner and the lower left corner of the vertical frame 13A, and the reaction axis A3 intersects the upper left corner and the lower right corner of the vertical frame 13A. In the second frame 13, a force f6 is generated in the clockwise direction around the first axis A1, and a force f7 is generated in the counterclockwise direction around the second axis A2. As a result of the generation of these forces f6 and f7, a reaction force RF is generated around the reaction axis A3 as a whole in the second frame 13.

[0024] Specifically, the reaction axis A3 moves around the second rotation axis x2 to a position where it intersects with the first axis A1 and the second axis A2 at an angle of 135 degrees, corresponding to the angle of the rotor 11 around the second rotation axis x2, i.e., 135 degrees. In this example, the position of the angle (135 degrees) of the reaction axis A3 around the second rotation axis x2 is equidistant from the first axis A1 and the second axis A2, so the magnitude of the force f6 around the first axis A1 is equal to the magnitude of the force f7 around the second axis A2. However, while force f6 occurs in the counterclockwise direction, force f7 occurs in the clockwise direction. The resultant force resulting from the combination of these forces f6 and f7 generates a reaction force RF that tends to rotate the second frame 13 as a whole clockwise around the reaction axis A3. Specifically, a reaction force RF that tends to move the upper right corner and the lower left corner of the vertical frame 13A clockwise around the reaction axis A3 is generated.

[0025] Next, assume that the rotor 11 moves from the angle (0 degrees) position in FIG. 1 to the angle (165 degrees) position in FIG. 6 . In other words, assume that the first rotation axis x1 moves from the angle (0 degrees) position around the second rotation axis x2 to the angle (165 degrees) position. As shown in FIG. 6 , as the first rotation axis x1 moves around the second rotation axis x2, the first rotation axis x1 intersects with the right and left portions of the vertical frame 13A, and the reaction force axis A3 intersects with the upper and lower portions of the vertical frame 13A. As a result, a force f8 is generated in the second frame 13 in the counterclockwise direction around the first axis A1, and a force f9 is generated in the clockwise direction around the second axis A2. As a result of the generation of these forces f8 and f9, a reaction force RF is generated around the reaction force axis A3 as a whole in the second frame 13.

[0026] Specifically, the reaction axis A3 moves around the second rotation axis x2 to a position where it intersects with the first axis A1 and the second axis A2 at an angle of 165 degrees, corresponding to the angle of the rotor 11 around the second rotation axis x2, i.e., 165 degrees. In this example, the position of the angle (165 degrees) of the reaction axis A3 around the second rotation axis x2 is closer to the first axis A1 than the second axis A2, so the magnitude of the force f9 around the second axis A2 is smaller than the magnitude of the force f8 around the first axis A1. As a result, the resultant force of these forces f8 and f9 generates a reaction force RF that tends to rotate the second frame 13 as a whole clockwise around the reaction axis A3. Specifically, the reaction force RF that tends to move the upper and lower portions of the vertical frame 13A in a clockwise direction around the reaction axis A3 is generated. In addition, the components of the reaction force RF that tend to move the upper right corner and the lower left corner of the vertical frame 13A are greater than the components of the reaction force RF that tend to move the upper left corner and the lower right corner of the vertical frame 13A.

[0027] Next, assume that the rotor 11 moves from the angle (0 degrees) position in FIG. 1 to the angle (180 degrees) position in FIG. 7 . In other words, assume that the first rotation axis x1 moves from an angle of 0 degrees around the second rotation axis x2 to an angle of 180 degrees. As shown in FIG. 7 , as the first rotation axis x1 moves around the second rotation axis x2, the first rotation axis x1 coincides with the second axis A2. Furthermore, the reaction force axis A3 defined by the rotor 11 coincides with the first axis A1. As a result, a force f10 is generated in the second frame 13 in the clockwise direction around the first axis A1. On the other hand, no force is generated in the second frame 13 around the second axis A2. As a result, a reaction force RF is generated in the second frame 13 as a whole around the reaction force axis A3.

[0028] Specifically, the reaction axis A3 moves around the second rotation axis x2 to a position where it intersects with the second axis A2 at a 90-degree angle, corresponding to the angle of the rotor 11 around the second rotation axis x2, i.e., 180 degrees. Furthermore, the reaction axis A3 is perpendicular to the first rotation axis x1 and the second rotation axis x2 at the intersection of the first axis A1 and the second axis A2. As a result, the resulting force f10 generates a reaction force RF that tends to rotate the second frame 13 as a whole counterclockwise around the reaction axis A3. Specifically, a reaction force RF that tends to move the upper and lower portions of the vertical frame 3A clockwise around the reaction axis A3 is generated.

[0029] As described above, in the analytical model 10, while the rotor 11 rotates around the first rotation axis x1, when the rotor 11, i.e., the first rotation axis x1, moves around the second rotation axis x2, forces, i.e., torques, are generated around the first axis A1 and the second axis A2. FIG. 8 is a graph showing changes in torque at each angular position around the second rotation axis x2. As shown in FIG. 8, the magnitude (absolute value) of the torque F1 around the first axis A1 (z-axis) is defined by a sine wave that has a maximum value (i.e., 1) at 0 degrees and 180 degrees and a minimum value (i.e., 0) at 90 degrees. Furthermore, the magnitude (absolute value) of the torque F2 around the second axis A2 (y-axis) is defined by a sine wave that has a maximum value at 90 degrees and a minimum value at 0 degrees and 180 degrees. Note that no torque F3 is generated around the second rotation axis x2 (x-axis) (i.e., torque F3 is always zero).

[0030] As is clear from FIG. 8 , torque F1 and torque F2 change from 180 degrees to 360 degrees in an inverse manner to the change from 0 degrees to 180 degrees. That is, the magnitude (absolute value) of torque F1 reaches maximum values ​​at 0 degrees, 180 degrees, and 360 degrees, and reaches minimum values ​​at 90 degrees and 270 degrees. Similarly, the magnitude (absolute value) of torque F2 reaches maximum values ​​at 90 degrees and 270 degrees, and reaches minimum values ​​at 0 degrees, 180 degrees, and 360 degrees. Due to these changes in torque F1 and torque F2, the magnitude of reaction force RF, which is the resultant of torques F1 and F2, is always constant (i.e., 1) for the entire analysis model 10, even when the rotor 11 rotates 360 degrees around the first rotation axis x1. Note that, as a condition for this, it is necessary that the speed of rotation of the rotor 11 around the first rotation axis x1 and the speed of movement around the second rotation axis x2 are constant.

[0031] However, as also shown in FIGS. 2 to 7 , the direction of the generated reaction force RF changes as the first rotation axis x1 (i.e., reaction axis A3) moves around the second rotation axis x2. Specifically, as the rotor 11, i.e., the first rotation axis x1, moves around the second rotation axis x2, the reaction axis A3 also moves around the second rotation axis x2. As a result, the direction of the reaction force RF generated around the reaction axis A3 changes as the reaction axis A3 moves around the second rotation axis x2. For example, between the 45-degree position in FIG. 2 and the 135-degree position in FIG. 5 , the reaction axis A3 also moves 90 degrees around the second rotation axis x2, corresponding to the difference of 90 degrees around the second rotation axis x2. As a result, the direction of the reaction force RF also changes by 90 degrees around the second rotation axis x2.

[0032] Furthermore, relative to the stationary second frame 13, in the angle range of 180 degrees to less than 360 degrees around the second rotation axis x2, the direction of rotation of the rotor 11 around the first rotation axis x1 is opposite to that in the angle range of 0 degrees to less than 180 degrees around the second rotation axis x2. Therefore, in the angle range of 180 degrees to less than 360 degrees around the second rotation axis x, the direction of the reaction force RF generated in the analysis model 10 is opposite to that in the angle range of 0 degrees to less than 180 degrees around the second rotation axis x2. In other words, for example, by changing the direction of rotation of the rotor 11 around the second rotation axis x2 to the opposite direction, the direction of the reaction force RF generated in the analysis model 10 can be changed to the opposite direction. Note that the magnitude of the reaction force RF increases in proportion to the rotation speed of the rotor 11 around the first rotation axis x1 and the movement speed of the rotor 11 around the second rotation axis x2.

[0033] FIG. 9 is a partial perspective view schematically illustrating the structure of a reaction force generator 1 that executes the operation of an analytical model 10. The reaction force generator 1 is a device that realizes the aforementioned analytical model 10, configured to generate a reaction force using the so-called gyroscopic effect. The reaction force generator 1 includes a rotor 2, a first motor 3, a first frame 4, a second motor 5, and a second frame 6. The reaction force generator 1 can be used, for example, in a game controller or wearable device that generates stimuli such as tactile, kinematic, or impact, or in a device (electronic device) that generates stimuli such as tactile, kinematic, or impact in a space, such as virtual reality (VR) or augmented reality (AR). An example of a device (electronic device) equipped with the reaction force generator 1 is a game controller.

[0034] The first motor 3 rotates the rotor 2 around a first rotation axis x1. The first motor 3 is fixed to the first frame 4. The second motor 5 moves the first frame 4 around a second rotation axis x2 that is perpendicular to the first rotation axis x1. In this example, the second motor 5 is fixed to the second frame 6. In this example, the second frame 6 defines an internal space that accommodates, for example, the rotor 2, the first motor 3, the first frame 4, and the second motor 5. In FIG. 9 , a portion of the second frame 6 is shown transparent. Therefore, the rotor 2, the first motor 3, the first frame 4, and the second motor 5 accommodated in the accommodation space within the second frame 6 can be seen through the second frame 6. In other words, the first frame 4 and the second frame 6 form a housing having an internal space.

[0035] In this reaction force generator 1, a first axis A1 is defined in the z-axis direction and a second axis A2 is defined in the y-axis direction relative to the second frame 6. In this example, the first axis A1 is defined in the up-down direction of the reaction force generator 1. The second axis A2 is defined in the left-right direction of the reaction force generator 1. The second axis A2 is also perpendicular to the position where the first rotation axis x1 and the second rotation axis x2 are perpendicular to each other. In this example, the second rotation axis x2 and the second axis A2 are defined to pass through the centers of gravity of the rotor 2, the first motor 3, and the first frame 4. However, the second rotation axis x2 and the second axis A2 may be defined away from the centers of gravity of the rotor 2, the first motor 3, and the first frame 4. In this example, the reaction force axis A3 of the rotor 2 coincides with the second axis A2. That is, in this example, the reaction force axis A3 passes through the centers of gravity of the rotor 2, the first motor 3, and the first frame 4.

[0036] The rotor 2 is formed, for example, by a disk-shaped weight. The rotor 2 is formed, for example, from a metal material containing lead or the like. The first motor 3 is, for example, a brushed DC motor. The first motor 3 can rotate the rotor 2 in both directions around the first rotation axis x1. In one example, the rotor 2 is supported on the output shaft 31 of the first motor 3. The first frame 4 has a base 41 to which the first motor 3 is fixed, a pair of side portions 42, 42 that stand upright in the z-axis direction from both ends of the base 41 in the x-axis direction, and a pair of shaft portions 43 (one of which is not shown) that protrude in opposite directions in the x-axis direction from the outer surfaces of the pair of side portions 42, 42 that face each other. The rotor 2 and the first motor 3 are disposed between the pair of side portions 42, 42. In this example, the base 41, the side portions 42, and the shaft portion 43 are integrally formed, for example, from a resin material.

[0037] The second motor 5 is disposed on one side of the first frame 4 in the x-axis direction. One shaft portion 43 of the first frame 4 is connected to an output shaft (not shown) of the second motor 5. The output shaft of the second motor 5 rotates around the second rotation axis x2. The other shaft portion (not shown) of the first frame 4 is rotatably supported, for example, by a bearing 7 fixed to the second frame 6. The bearing 7 is, for example, a ball bearing. In this way, the first frame 4 (as well as the rotor 2 and first motor 3) can be moved around the second rotation axis x2 by the second motor 5. The second motor 5 is, for example, a stepping motor. The second motor 5 can move the first frame 4 by a predetermined angle in both directions around the second rotation axis x2.

[0038] In the reaction force generator 1 described above, when current is supplied to the second motor 5, the second motor 5 holds the first frame 4, i.e., the rotor 2, at a predetermined reference position around the second rotation axis x2 relative to the second frame 6. Furthermore, when current is supplied to the first motor 3, the first motor 3 rotates the rotor 2 in a predetermined direction around the first rotation axis x1. At this time, the second motor 5 moves the first frame 4, i.e., the rotor 2, around the second rotation axis x2 at a predetermined speed through a predetermined angle, and holds the rotor 2 at that angle. As a result, a moment is applied to the rotor 2 rotating around the first rotation axis x1 in the direction of movement around the second rotation axis x2. As a result, a reaction moment, i.e., a reaction force, is generated in the rotor 2 due to the gyroscopic effect in a direction different from the first rotation axis x1 and the second rotation axis x2.

[0039] Here, to briefly explain the gyro effect, if the angular momentum of the rotor 2 around the first rotation axis x1 is L, the moment of inertia is I, and the angular velocity of the movement around the second rotation axis x2 is ω, then L = Iω holds. Also, the moment acting on the rotor 2 at the reference position around the first rotation axis x1 is T ａ , where t is the moving time of the rotor 2, the following formula 1 holds: If the time at the reference position is t=0, the time when the rotor 2 moves around the second rotation axis x2 through a predetermined angle is t=t. The movement of the rotor 2 around the second rotation axis x2 generates a moment T in a direction perpendicular to the first axis A1 of the reference position. ａ This moment T calculated based on Equation 1 is generated. ａ is the moment T ａ The reaction moment in the opposite direction (-T ａ ) that is, reaction force T ｇ Corresponds to.

[0040] In the reaction force generating device 1 described above, the rotor 2 is rotatable about the first rotation axis x1 and movable about the second rotation axis x2 that is perpendicular to (intersects) the first rotation axis x1. With this configuration, the rotor 2 rotates about the first rotation axis x1 and moves about the second rotation axis x2 through a predetermined angle, thereby generating a reaction force about the reaction axis A3 that is perpendicular to (intersects) the first rotation axis x1 and the second rotation axis x2. Furthermore, the rotor 2 moving about the second rotation axis x2 through a predetermined angle also moves the reaction axis A3 about the second rotation axis x2. As a result, as will be described later, the generation of the reaction force RF (e.g., the direction of the reaction force RF) can be controlled by the angular position of the reaction axis A3 about the second rotation axis x2.

[0041] Next, an example of controlling the generation of the reaction force RF in the reaction force generating device 1 described above will be described below. In a first specific example, a reaction force RF of the same magnitude and in the same direction is intermittently generated. This example will be described using an analytical model 10. FIG. 10 is a schematic diagram for explaining a first specific example of controlling the generation of the reaction force RF. As shown in FIG. 10, for example, the rotor 11, i.e., the first rotation axis x1, is initially positioned at 0 degrees in FIG. 2. The rotor 11 is rotated around the first rotation axis x1 in a predetermined third direction (e.g., clockwise) at a predetermined first speed. The rotor 11 is moved around the second rotation axis x2 in a predetermined first direction D1 (e.g., clockwise) over a predetermined angle at a predetermined speed. In this example, the predetermined angle is set to, for example, 45 degrees. In this way, as described above, a reaction force RF is generated that tends to rotate the second frame 13 clockwise around the reaction axis A3.

[0042] Then, while maintaining rotation about the first rotation axis x1 in the third direction at a predetermined speed, the rotor 11 is moved about the second rotation axis x2 in a second direction D2 opposite to the first direction D1 over a predetermined angle at a predetermined speed. In one example, the rotor 11 moves in the second direction D2 about the second rotation axis x2 over the same angle (i.e., 45 degrees) as the movement in the first direction. The rotor 11 returns to its initial position. During this movement in the second direction D2, the second speed of rotation of the rotor 11 about the first rotation axis x1 is smaller than the first speed of rotation of the rotor 11 about the first rotation axis x1 during movement in the first direction. In one example, the second speed is set to a magnitude that does not generate a reaction force RF about the reaction force axis A3. This setting prevents the generation of a reaction force RF when the rotor 11 returns from the 45-degree position to the 0-degree position about the second rotation axis x2.

[0043] Thus, as the rotor 11 moves around the second rotation axis x2 in the first direction D1 and the second direction D2, which are opposite to each other, the reaction axis A3 moves around the second rotation axis x2 in two opposite directions. This movement of the rotor 11 in the first direction D1 and the second direction D2 is repeated multiple times. By moving the rotor 11, i.e., the reaction axis A3, around the second rotation axis x2 through the same angle, a reaction force RF is generated, for example, when moving in the first direction D1, and the generation of the reaction force RF is suppressed when moving in the second direction D2, which is opposite to the first direction D1. As a result, a reaction force RF of the same magnitude and direction is generated only when moving in the first direction D1. In this way, the same reaction force RF can be repeatedly generated. It is preferable that the movement of the reaction axis A3 around the second rotation axis x2 be within an angle range of, for example, greater than 0 degrees and less than 90 degrees.

[0044] In the first specific example described above, when the rotor 11 moves in the second direction D2 around the second rotation axis x2, the rotor 11 may rotate in a fourth direction (e.g., counterclockwise) opposite to the predetermined third direction (e.g., clockwise). However, in this case, it is preferable that the rotation speed of the rotor 11 around the first rotation axis x1 be set equal when moving in the first direction D1 and when moving in the second direction D2. With this setting, the reaction force RF generated when the rotor 11 moves in the first direction D1 is the same as the reaction force RF generated when the rotor 11 moves in the second direction D2. Therefore, with this setting, a reaction force RF is generated when the rotor 11 moves in the first direction D1, and the same reaction force RF is also generated when the rotor 11 moves in the second direction D2, so that reaction forces RF of the same magnitude and in the same direction can be continuously generated.

[0045] Next, a second specific example of controlling the generation of reaction force RF will be described below, instead of the first specific example. In this second specific example, a relatively large reaction force RF is generated within a specific first angle range around the second rotation axis x2. In this example, a reaction force RF smaller than the reaction force RF within the first angle range is generated within a second angle range around the second rotation axis x2 that is different from the first angle. FIG. 11 is a schematic diagram illustrating the second specific example of controlling the generation of reaction force RF. As shown in FIG. 11 , the speed of movement of the rotor 11 around the second rotation axis x2 within a first angle range R1 is set to a first speed, and the speed of movement of the rotor 11 around the second rotation axis x2 within a second angle range R2 is set to a second speed that is different from the first speed (in this case, smaller than the first speed).

[0046] In this example, the first angle range R1 is different from the second angle range R2. For example, if the reference position of the rotor 11 shown in FIG. 2 is 0 degrees, the first angle range R1 is set to a range from 0 degrees (the reference position) to less than 180 degrees around the second rotation axis x2, and the second angle range R2 is set to a range from 180 degrees to less than 360 degrees (i.e., the reference position of 0 degrees) around the second rotation axis x2. The rotation speed of the rotor 11 around the first rotation axis x1 is set to be equal in the first angle range R1 and the second angle range R2. Furthermore, the movement of the rotor 11 around the second rotation axis x2 is set to be in the same direction (e.g., clockwise) in the first angle range R1 and the second angle range R1.

[0047] According to this setting, a relatively large reaction force RF can be generated by moving the rotor 11 at a relatively large first speed in the first angle range R1 about the second rotation axis x2. On the other hand, a relatively small reaction force RF can be generated by moving the rotor 11 at a relatively small second speed in the second angle range R2 about the second rotation axis x2. In this way, a relatively large reaction force can be generated around the reaction force axis A3 in a specific angle range (first angle range) about the second rotation axis x2. Note that the speed of movement of the rotor 11 about the second rotation axis x2 may be set to a magnitude that does not generate a reaction force RF in the second angle range R2, for example.

[0048] In the second specific example, two ranges, a first angle range R1 and a second angle range R2, are set around the second rotation axis x2. However, for example, three or more angle ranges R may be set. Furthermore, in the second specific example, instead of providing a difference in the speed of movement of the rotor 11 around the second rotation axis x2, a difference in the speed of rotation of the rotor 11 around the first rotation axis x1 may be provided. That is, the speed of rotation of the rotor 11 around the first rotation axis x1 may be set to a relatively high first speed in the first angle range R1 and to a lower second speed in the second angle range R2. Furthermore, for example, the direction of movement of the rotor 11 around the first rotation axis x1 may be set to a first direction (e.g., clockwise) in the first angle range R1 and to a second direction (e.g., counterclockwise) opposite to the first direction in the second angle range R2. This setting also allows the generation of a reaction force RF in various patterns.

[0049] Furthermore, the first motor 3 may be a brushless DC motor or a stepping motor instead of a brushed DC motor, and the second motor 5 may be a brushless DC motor or a brushed DC motor instead of a stepping motor. The reaction force generator 1 may be mounted on a game controller or a wearable device that generates stimuli such as tactile, kinematic, or impact, or on a device (electronic device) that generates stimuli such as tactile, kinematic, or impact in space, such as virtual reality (VR) or augmented reality (AR). The reaction force generator may also be attached to a housing or frame included in such electronic devices. In the above-described embodiment, the first frame 4 and the second frame 6 form a housing having an internal space. However, this is not limited thereto. The first motor 3 may include a first frame, and the second motor 5 may include a second frame. For example, as shown in FIG. 9 , a housing 8 may be further provided to house the first motor 3 and the second motor 5. The shape of the housing 8 shown in FIG. 9 is merely an example, and the housing 8 may have various shapes depending on its intended use.

[0050] Although the present invention has been described above through the above embodiments, the technical scope of the present invention is not limited to the scope described in the above embodiments. It will be apparent to those skilled in the art that various modifications and improvements can be made to the above embodiments. It is clear from the claims that such modifications and improvements can also be included within the technical scope of the present invention.

[0051] The above-described embodiments are intended to facilitate understanding of the present invention and are not intended to limit the scope of the present invention. Furthermore, the above-described embodiments do not limit the scope of the present invention, and the present invention may include any and all applications. The components of the above-described embodiments, as well as their arrangement, materials, conditions, shapes, sizes, and the like, are not limited to those exemplified and may be modified as appropriate.

[0052] For example, the present invention includes differences that occur during implementation, such as manufacturing tolerances. Furthermore, within the scope of technical inconsistencies, components shown in different embodiments can be partially substituted or combined. Furthermore, each configuration can be appropriately and selectively combined to achieve at least some of the above-described problems and effects.

[0053] REFERENCE SIGNS LIST 1 reaction force generating device, 2 rotor, 3 first motor, 4 first frame, 41 base, 42 side, 43 shaft, 5 second motor, 6 second frame, 7 bearing, 8 housing, 10 analysis model, 11 rotor, 111 weight, 111a first surface, 111b second surface, 112 shaft, 12 first frame, 13 second frame, 13A vertical frame, 13B horizontal frame, A1 first axis, A2 second axis, A3 reaction force axis, f1 to f10 force, RF reaction force, x1 first rotation axis, x2 second rotation axis

Claims

1. A reaction force generating device comprising a rotor that is rotatable about a first rotation axis and movable about a second rotation axis that is perpendicular to or intersects the first rotation axis, wherein the rotor rotates about the first rotation axis and moves about the second rotation axis through a predetermined angle, thereby generating a reaction force about a reaction axis that is perpendicular to or intersects the first rotation axis and the second rotation axis, and the rotor that moves about the second rotation axis through the predetermined angle causes the reaction axis to move about the second rotation axis.

2. A reaction force generating device as described in claim 1, wherein the rotor moves through a predetermined angle in a first direction about the second rotation axis, and then moves through a predetermined angle in a second direction about the second rotation axis opposite to the first direction, thereby causing the reaction force axis to move in two directions about the second rotation axis.

3. The reaction force generating device according to claim 2, wherein the angle of movement of the rotor in the first direction is equal to the angle of movement of the rotor in the second direction.

4. A reaction force generating device according to claim 2 or 3, wherein the speed of rotation of the rotor in the second direction is slower than the speed of rotation of the rotor in the first direction.

5. A reaction force generating device according to claim 4, wherein the speed of rotation of the rotor in the second direction is set to a magnitude that does not generate a reaction force around the reaction force axis.

6. A reaction force generating device according to any one of claims 2 to 5, wherein the movement of the rotor in the first direction and the movement of the rotor in the second direction are repeated multiple times.

7. A reaction force generating device according to any one of claims 2 to 6, wherein when the rotor moves in the first direction and when the rotor moves in the second direction, the rotor rotates in a third direction around the first rotation axis.

8. A reaction force generating device according to any one of claims 2 to 6, wherein when the rotor moves in the first direction, the rotor rotates in a third direction around the first rotation axis, and when the rotor moves in the second direction, the rotor rotates in a fourth direction opposite to the third direction around the first rotation axis.

9. The reaction force generating device according to claim 8, wherein the speed of rotation of the rotor in the third direction is equal to the speed of rotation of the rotor in the fourth direction.

10. A reaction force generating device as described in claim 1, wherein the speed of movement of the rotor around the second rotation axis is set to a first speed within a first angle range around the second rotation axis, and is set to a second speed different from the first speed within a second angle range around the second rotation axis.

11. A reaction force generating device according to claim 10, wherein the movement of the rotor in the first angular range is in the same direction about the second rotation axis as the movement of the rotor in the second angular range.

12. The reaction force generating device according to claim 10, wherein the movement of the rotor in the first angular range is in a first direction about the second rotational axis, and the movement of the rotor in the second angular range is in a second direction about the second rotational axis that is opposite to the first direction.

13. A reaction force generating device according to any one of claims 10 to 12, wherein the first angle range is different from the second angle range.

14. An electronic device comprising: a housing; and a reaction force generating device according to any one of claims 1 to 13, wherein the reaction force generating device is attached to the housing.

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