JP7046343B2 - Braking mechanism, reaction wheel with braking mechanism, reaction wheel device, reaction wheel system - Google Patents

Description

The present invention relates to a reaction wheel including a braking mechanism and a braking mechanism, and more particularly to a reaction wheel including a braking mechanism using an electromagnet and a braking mechanism using an electromagnet.

The electromagnetic brake used for braking a conventional rotating body has a structure as schematically shown in FIG. That is, in the electromagnetic brake, an armature 902 made of a ferromagnetic material is attached to the rotating body 901 via an urging member 903 such as a leaf spring, and is fixed to the rotating body 901 at a predetermined distance from the armature 902. An electromagnet 905 is arranged. Then, when the electromagnet 905 is excited, the armature 902 comes into contact with the electromagnet 905 against the urging force of the urging member 903 by the magnetic flux generated by the magnetic flux, and the rotating body 901 is braked.

Further, a 15 cm cubic three-dimensional inverted pendulum having an orthogonal internal arrangement of three reaction wheels has been reported (Non-Patent Document 1). This three-dimensional inverted pendulum controls the posture by the reaction force of the flywheel, keeps the balance at the ridges (sides) and corners of the cube, and makes a steep movement by suddenly stopping the rotational movement of the flywheel with a servo motor. It has been realized. The braking mechanism of the flywheel has the structure shown in FIG. That is, the flywheel 914 is suddenly stopped by abruptly colliding the brake pad 913 provided at the end of the arm 912 attached to the servomotor 911 with the protrusion 915 attached to the flywheel 914. ..

Mohanarajah Gajamohan, Michael Merz, Igor Thommen and Raffaello D’ Andrea, "The Cubli: A Cube that can Jump Up and Balance," 2012 IEEE / RSJ International Conference on Intelligent Robots and Systems, 2012, pp. 3722 --3727

Braking mechanisms and reaction wheels are required to be smaller, lighter, and have a longer life.

In this respect, in the above-mentioned three-dimensional inverted pendulum, a brake pad is attached to the end of the servomotor in order to realize a steep movement, and the reaction wheel can be suddenly stopped. However, this method has problems such as sudden mechanical wear and damage of the pad portion due to the inability to obtain a large area in contact with the wheel rotating at high speed. Therefore, there is a limit to the reproducibility of operation and the operation life. In addition, a servomotor, driver, and brake pad mechanism are required for each of the reaction wheels of each of the three axes, and it is necessary to secure that space on the top and sides of each reaction wheel, which complicates the system and makes the entire module. Is difficult to miniaturize.

Therefore, one of the objects of the present invention is to provide a compact, lightweight, long-life braking mechanism and reaction wheel.

One aspect of the present invention is a frame, a rotating body arranged to face the frame, an electromagnet arranged between the frame and the rotating body, and an electromagnet attached to the frame. A urging member for urging the frame side is provided, and at least a part of the portion of the rotating body facing the electromagnet is formed of a ferromagnetic material, and the electromagnet and the rotating body are formed when the electromagnet is not excited. The electromagnet is urged by the urging member so as to be separated from each other, and when the electromagnet is excited, the electromagnet comes into contact with the rotating body against the urging force of the urging member, thereby braking the rotating body. It provides a braking mechanism.

The braking mechanism can suddenly stop the rotating body when the electromagnet is excited.

The rotating body may be formed with a recess capable of accommodating at least a part of the electromagnet on the side facing the electromagnet, and the rotating body may be arranged so as to cover the electromagnet.

The electromagnet can have a ring shape or an arc shape.

The surface of the electromagnet in contact with the rotating body when the electromagnet is excited and the surface of the rotating body in contact with the electromagnet when the electromagnet is excited can have complementary shapes.

It is possible that the electromagnet comes into contact with the outer edge of the rotating body when the electromagnet is excited.

The urging member can be a leaf spring.

The braking mechanism may further include a wireless communication unit, and the control unit may be remotely controllable via the wireless communication unit.

Another aspect of the present invention is to provide a reaction wheel provided with the braking mechanism.

It is possible that the portion of the rotating body other than the portion on the side facing the electromagnet is formed of a material having a higher density than the ferromagnetic material.

Another aspect of the present invention comprises the two or more reaction wheels described above and a control unit that controls the excitation state of each of the electromagnets of the two or more reaction wheels. The present invention provides a reaction wheel device in which the directions of the rotation axes of the rotating bodies of the two or more reaction wheels are different from each other.

The two or more reaction wheels are three reaction wheels, and the three reaction wheels can be arranged so that the rotation axes of the rotating bodies of the three reaction wheels are orthogonal to each other.

The shape of the frame of the three reaction wheels can be the same square shape.

Another aspect of the invention is a first reaction wheel with a first rotating body that rotates in a first direction around the axis of rotation and in a direction coaxial with or parallel to the axis of rotation. A pair of reaction wheels including a second reaction wheel having a second rotating body that rotates in a second direction opposite to the first direction around the axis of rotation, and the first rotating body and the first rotating body. A control unit for controlling the rotational state of each of the two rotating bodies is provided, and the control unit is such that the absolute values of the angular momentums of the first rotating body and the second rotating body are equal to each other. The rotating body and the second rotating body are rotated, and in response to the motion start signal, the rotation of the rotating body of one of the reaction wheel pairs is suddenly stopped, and the rotation of the rotating body of the other reaction wheel is stopped. It provides a reaction wheel system that keeps rotating and then suddenly stops the rotation of the rotating body of the other reaction wheel in response to a motion end signal. In response to the motion start signal, the rotation of the rotating body of one of the reaction wheel pairs is suddenly stopped, and the rotation of the rotating body of the other reaction wheel is continued, so that the rotating body of the reaction wheel system is rotated. The rotational direction of the rotating body of the one reaction wheel by causing the angular momentum exchange between the moving body which is a device (for example, a spacecraft) in which the reaction wheel system is installed and the other part or the one reaction wheel. The angular momentum in the same direction as is immediately generated in the moving body, and the moving body is rotated. Then, in response to the motion end signal, the rotation of the rotating body of the other reaction wheel is suddenly stopped to cause angular momentum exchange between the moving body and the other reaction wheel, and the angular momentum of the moving body is generated. The angular momentum of the other reaction wheel, which is opposite to and of the same magnitude, is added to the moving body, the angular momentum of the moving body is offset, and the rotational movement of the moving body can be stopped immediately. In both the initial state and the final state, the angular momentum of the entire system consisting of the reaction wheel pair and the moving body is zero, but the difference between the two is that both rotating bodies of the reaction wheel pair are in opposite directions in the initial state. While it is rotating with the same angular momentum absolute value, in the final state, the rotation of both rotating bodies of the reaction wheel pair is stopped.

The first rotating body and the second rotating body can have the same shape and the same moment of inertia.

The first reaction wheel and the second reaction wheel can be the reaction wheel described above.

Another aspect of the present invention comprises the two reaction wheel devices described above, wherein the first reaction wheel is one of the two or more reaction wheels of one of the two reaction wheel devices. The second reaction wheel provides the reaction wheel system described above, which is one of the two or more reaction wheels on the other side of the two reaction wheel devices.

The reaction wheel system is one of the two or more reaction wheels on one of the two reaction wheel devices and two said for each of the directions of the rotation axis of the rotating body of the two or more reaction wheels. The reaction wheel pair comprising one of the two or more reaction wheels on the other side of the reaction wheel device can be provided.

Another aspect of the present invention is a control unit that controls the rotational state of each of the n (n ≧ 3) reaction wheels having a rotating body that rotates around the rotation axis and the rotating bodies of the n reaction wheels. The control unit rotates the rotating bodies of the n reaction wheels so that their total angular momentum is zero, and in response to the movement start signal, one or more of them are all. No reaction A reaction that suddenly stops the rotation of the rotating body of the wheel, keeps the rotating body of the remaining reaction wheel rotating, and then suddenly stops all the rotation of the rotating body in response to the motion end signal. It provides a wheel system.

In the present specification and claims, "sudden stop" means, for example,, but not limited to, stopping the rotating body in a time of about 1 s or less.

According to the present invention having the above configuration, a compact, lightweight, long-life braking mechanism and reaction wheel are provided.

It is a perspective view of the reaction wheel which concerns on 1st Embodiment of this invention. It is an exploded perspective view of the reaction wheel which concerns on 1st Embodiment of this invention. FIG. 3 is a cross-sectional view taken along the line III-III of FIG. It is a perspective view of the reaction wheel device which concerns on 2nd Embodiment of this invention. It is a figure which shows the operation principle of the reaction wheel system which concerns on 3rd Embodiment of this invention. It is a perspective view of the reaction wheel system which concerns on 3rd Embodiment of this invention. It is a figure which shows the operation principle of the reaction wheel system which concerns on 4th Embodiment of this invention. It is a perspective view of the reaction wheel system which concerns on 4th Embodiment of this invention. It is a figure which shows typically the structure of the conventional electromagnetic brake. It is a figure which shows the structure of the braking mechanism of the conventional three-dimensional inverted pendulum.

Hereinafter, embodiments of the present invention will be described with reference to the drawings.

1 is a perspective view of the reaction wheel according to the first embodiment of the present invention, FIG. 2 is an exploded perspective view of the reaction wheel according to the first embodiment of the present invention, and FIG. 3 is III- of FIG. III is a cross-sectional view.

As shown in FIGS. 1 to 3, the reaction wheel 1 according to the present embodiment includes a frame 10, a leaf spring 11 as an urging member, an electromagnet 12, a flywheel 13 as a rotating body, and a motor 14. In preparation, they are arranged in this order.

The frame 10 has a square-shaped first frame portion 101 and a cross-shaped second frame portion 102 arranged so as to connect the vertices of the first frame portion 101. The weight of the frame can be reduced by having an opening in the frame in this way. The frame may have a plate-like structure without openings, and the number and shape of the openings may be any appropriate number and shape. A hole 103 for passing the shaft 143 of the motor 14 is provided in the center of the second frame portion 102. A support column 15 is fixed to one of the corners of the frame 10 by a screw, and one end of a support arm 16 is connected to the support column 15 by a screw. A motor mount 17 is integrally connected to the other end of the support arm 16.

The motor 14 includes a substantially cylindrical motor body 141 and a shaft 143, and rotates a flywheel 13 described later attached to the shaft 143. The motor body 141 has a cylindrical convex portion 141a protruding in the center in the axial direction. A hole 171 is provided in the motor mount 17, a convex portion 141a is fitted into the hole 171 and the motor main body 141 is placed and fixed on the motor mount 17.

The flywheel 13 has a main body portion 131 and a spoke portion 132 that are integrally formed, and is made of a ferromagnetic material. The main body 131 is formed in an annular shape, and the spokes are provided inside the main body 131. A chamfered portion is formed on one end side of the outer peripheral surface of the main body portion 131 in the axial direction. With such a configuration, for example, when forming a three-axis reaction wheel device as described later, adjacent reaction wheels can be arranged closer to each other, and the device can be further miniaturized. A recess 131a capable of accommodating the electromagnet 12 is formed on the side of the main body 131 facing the electromagnet 12, and the surface of the recess 131a facing the electromagnet is formed on a flat surface. A hole 133 is provided in the center of the spoke portion 132 for passing the shaft 143 of the motor 14 and fitting the convex portion 183 of the connecting member 18 described later. A connecting member 18 is fixed to the frame side of the spoke portion 132. The connecting member 18 has a cylindrical portion 181 and a flange portion 182, and a convex portion 183. The connecting member 18 is fixed to the shaft 143 of the motor 14 by the potato screw 184. A washer 191 is arranged on the frame side of the flange portion 182, and the washer 191 and the connecting member 18 are attached to the spoke portion 132 of the flywheel 13 by a screw 193. A spring 192 is arranged between the washer 191 and the disc-shaped member 194 so as to surround the screw 193. The disk-shaped member 194 is fixed to the flywheel 13 side of the bearing 195. The shaft 143 of the motor 14 is supported by a bearing 195 mounted between the shaft 143 of the second frame portion 102 and the hole 103 at the center of the second frame portion 102.

As described above, in the present embodiment, the motor 14 and the flywheel 13 are mainly supported by the support column 15 and the support arm 16 provided on one side thereof, but the motor 14 and the flywheel 13 are mainly supported by the support arm 16 due to its own weight or the like. Since it is difficult to keep the gap between the braking surface 134 of the flywheel 13 and the first braking surface 121 of the electromagnet 12 constant, which will be described later, the frame 10 side of the motor 14 and the flywheel 13 is auxiliary with a spring 192. I support it. By using an auxiliary support structure, the motor 14 and the flywheel 13 are supported by the support pillar 15 and the support arm 16 provided on one side instead of both sides, so that the reaction of three axes as described later, for example, can be performed. When forming the wheel device, the adjacent reaction wheels can be arranged closer to each other, and the device can be further miniaturized.

The leaf spring 11 has a disk-like shape with a circular opening in the center. The leaf spring 11 is provided with four arc-shaped first slits 111 that are convex outward in the radial direction on the inner peripheral side of the leaf spring 11 at an angular interval of 90 ° in the circumferential direction. There is. The first slit 111 extends through the leaf spring 11 in the thickness direction, and the portion surrounded by the first slit serves as the first elastic imparting portion 112. Further, the leaf spring 11 is provided with four arc-shaped second slits 113 that are convex inward in the radial direction on the outer peripheral side of the leaf spring 11 in the circumferential direction at an angular interval of 90 °. .. The second slit 113 extends through the leaf spring 11 in the thickness direction, and the portion surrounded by the second slit 113 becomes the second elastic imparting portion 114. The first slit 111 and the second slit 113 are arranged alternately. The first elastic imparting portion 112 of the leaf spring 11 is fixed to the second frame portion 102 of the frame 10 via a screw. The shape, arrangement, number, etc. of the slit, that is, the elastic imparting portion may be any other appropriate shape, arrangement, number, etc. The shape of the leaf spring can also be any other suitable shape.

The electromagnet 12 has a ring shape, and its radial cross section is rectangular. The shape of the electromagnet 12 may be a part of the ring shape, that is, an arc shape, and one or more arc-shaped electromagnets 12 may be arranged. The shape of the electromagnet and the shape of the radial cross section can be any other suitable shape. The surface of the electromagnet 12 facing the frame 10 is fixed to the second elastic imparting portion 114 of the leaf spring 11 via a screw, and the leaf spring 11 urges the electromagnet 12 toward the frame 10. That is, even when the frame 10 is not arranged vertically below the electromagnet 12, the electromagnet 12 is urged by the leaf spring 11 so that the electromagnet 12 and the flywheel 13 are separated from each other when the electromagnet 12 is not excited, and the electromagnet 12 is used. Can be moved in the axial direction. The gap between the electromagnet 12 and the flywheel 13 is maintained at a predetermined distance. The structure (shape, shape and number of elastic imparting portions, etc.) and rigidity (material and thickness) of the leaf spring 11 can be determined by optimizing the relationship between the deflection of the leaf spring due to gravity and the attractive magnetic force. ..

As described above, the flywheel 13 is formed with a recess 131a capable of accommodating the electromagnet 12 on the side facing the electromagnet 12, and the flywheel 13 is arranged so as to cover the electromagnet 12. With such a configuration, the wall thickness of the outer edge portion of the flywheel 13 can be left on the outside of the electromagnet 12, and the moment of inertia of the flywheel 13 can be kept large. Further, with such a configuration, the dimension of the reaction wheel in the rotation axis direction can be reduced, and the reaction wheel can be miniaturized. The electromagnet 12 may be configured not to be entirely covered but to be partially covered.

In such a configuration, when the electromagnet 12 is excited during the rotation of the flywheel 13, the electromagnetic force generated by the magnetic flux causes the electromagnet 12 to urge the leaf spring 11 on the flywheel 13 formed of the ferromagnetic material. The flywheel 13 is braked by being attracted and contacted against the air. The braking state can be controlled by changing the magnitude of the magnetic flux generated by the electromagnet 12 and the rate of change of the magnetic flux. The rotating flywheel 13 can be suddenly stopped by stepping the change in the magnetic flux of the electromagnet 12 and generating a large magnetic force. As a result, the reaction wheel 1 can immediately reduce the generated angular momentum to zero.

With such a configuration, the armature mechanism of the conventional electromagnetic brake can be eliminated, the number of parts can be reduced, and the braking mechanism can be miniaturized.

In addition, the servomotor, motor driver, and brake pad drive mechanism used in the above-mentioned conventional three-dimensional inverted pendulum device are no longer required, and there are no parts to be placed around the flywheel, so the size of the flywheel can be reduced. It is possible to design the entire housing and reduce the size of the device. Further, since the servo motor is not required, the number of parts such as rotating parts and driver ICs can be reduced, the weight of the device can be reduced, the probability of failure can be reduced, and the reliability can be improved.

In addition, compared to the braking mechanism used in the conventional three-dimensional inverted pendulum device described above, the contact area between the flywheel that rotates at high speed and the brake pad can be made wider, so sudden wear damage can be prevented and the device can be prevented from being damaged. In addition to being able to extend the service life, stable torque performance can be ensured even if the number of brakes is repeated, and braking operation can be stabilized.

With such a configuration, the size is 100 mm in length, 100 mm in width, 28 mm or less in height, the braking torque is 2.1 Nm or more, the release (degaussing) time is 8 msec or less, and the braking time until complete stop is 100 ms or less, which is compact and lightweight. , It was possible to realize a braking mechanism that can stop the wheel suddenly.

In order to suddenly stop the flywheel 13 with higher responsiveness, the braking force may be increased. As one of the methods, it is conceivable to increase the contact area between the flywheel 13 and the electromagnet 12.

Specifically, the first braking surface 121, which is a surface that contacts the flywheel 13 of the electromagnet 12 when the electromagnet 12 is excited, and the second braking surface 134, which is a surface that contacts the flywheel 12 of the flywheel 13, are complemented. The shape may be similar. In the present embodiment, the first braking surface 121 of the electromagnet 12 and the second braking surface 131 of the flywheel 13 are planes parallel to each other and have a complementary shape. As a complementary shape, if a shape having a larger contact area between the electromagnet 12 and the flywheel 13, for example, a shape having an arcuate cross section is adopted, the braking force can be increased.

Further, if the electromagnet 12 is configured to be in contact with the outer peripheral portion side of the flywheel 13 when the electromagnet 12 is excited, the braking surface may be larger than that in the case where the electromagnet 12 is configured to be in contact with the central portion side of the flywheel 13. It will be possible. In the present embodiment, the contact area is increased and the braking force is increased by configuring the electromagnet 12 to come into contact with the outer edge portion of the flywheel 13 when the electromagnet 12 is excited.

In the above embodiment, the entire flywheel 13 is made of a ferromagnetic material, but if at least a part of the portion of the flywheel 13 facing the electromagnet 12 is made of a ferromagnetic material, braking can be performed. can. Then, if the other portion is formed of a material having a higher density than the ferromagnetic material (for example, tungsten), the mass of the flywheel 13 can be increased without increasing the volume of the flywheel 13, and the reaction wheel can be increased. The accumulated angular momentum per same rotation speed of 1 can be increased.

(Second embodiment)
FIG. 4 is a perspective view of the reaction wheel device according to the second embodiment of the present invention. With reference to FIG. 4, the configuration and operating principle of the second embodiment of the present invention will be described. In FIG. 4, the parts corresponding to FIGS. 1 to 3 are designated by the same reference numerals, and the description overlapping with the first embodiment will be omitted.

This embodiment is configured as a reaction wheel device capable of generating angular momentum with respect to three orthogonal axes by using three reaction wheels of the first embodiment.

The reaction wheel device 5 includes three reaction wheels 1, 2, and 3. The reaction wheels 1, 2, and 3 are arranged so that the directions of the rotation axes of the flywheels 13, 23, and 33 of the reaction wheels 1, 2, and 3 are orthogonal to each other. The frames 10, 20, and 30 of each reaction wheel have the same square shape. The frames 10, 20, 30 and the frames 40, 41, 42 having the same square shape as the frames 10, 20, 30 are formed by the brackets 551, 552, 552, 554, 555, 556, 557, 558, and the reaction wheel device 5 Are connected to each other so as to have a cubic shape as a whole.

Further, the reaction wheel device 5 is a power supply 54 which is a small battery such as a control unit 51, a MEMS sensor inertial measurement unit (IMU) 521, 524, 525, 526, 527, 528, a wireless communication unit 53, and a lithium polymer small battery. Is provided in the housing.

The control unit 51 controls the rotational state of each flywheel 13, 23, 33 by controlling the exciting currents of the motors 14, 24, 34 and the electromagnets 12, 22, 32 of the reaction wheels 1, 2, and 3, respectively. do. Further, the control unit 51 acquires information from the MEMS sensor IMU521, 524, 525, 526, 527, 528 and information from the wireless communication unit 53, performs various calculations based on this information, and obtains information. Based on the calculation result, the motors 14, 24, 34, the electromagnets 12, 22, 32, the power supply 54 are controlled, and information is transmitted to the wireless communication unit 53.

Six MEMS sensors IMU521, 524, 525, 526, 527, 528 are provided near the cube-shaped corners corresponding to the frame brackets 551, 554, 555, 556, 557, 558. Information from these MEMS sensors IMUs is transmitted to the control unit 51, and the gravitational acceleration direction and the like are obtained by the control unit 51 based on this information, and the rotational states of the flywheels 13, 23, and 33 are controlled.

The wireless communication unit 53 receives control information from a remote control device (not shown), transmits the control information to the control unit 51, and transmits information from the control unit 51 to the remote control device.

Since control can be performed from the remote control device via the wireless communication unit, there is no need to connect with a cable to an external device of the reaction wheel device, and the reaction wheel device fails when a failure occurs. It is not necessary to attach / detach the cable when replacing the wheel device, and the reaction wheel device can be easily replaced.

With such a configuration, the reaction wheel device can be miniaturized, and a reaction wheel device having a size of 10 cm cubic or less is realized, whereas the above-mentioned conventional three-dimensional inverted pendulum device has a size of 15 cm cubic. I was able to.

In addition, with such a configuration, it is possible to easily create a brake state and a free rotation state with high responsiveness by digitally turning on / off the electromagnet with a transistor or the like, and the reaction wheel device itself suddenly starts up. , It becomes possible to perform exercises such as rolling. Then, after the reaction wheel device has started up, the reaction force control of the flywheel allows the balance to be maintained at the unstable equilibrium points of the ridges (sides) and angles of the cube. In addition, it is possible to move while rotating in an arbitrary direction on rough terrain or slopes that are difficult to move with the wheel or walking type method. It is also highly useful as a surface movement technology for exploration robots on asteroids and the moon where such extremely steep terrain and regolith exist.

In the above embodiment, the number of reaction wheels is three, and the directions of the rotation axes of the flywheels of the reaction wheels are orthogonal to each other. However, if the directions of the rotation axes of the flywheels are different from each other, The number of reaction wheels can be any number of two or more.

In the above embodiment, a small battery is used as the power source, but wireless power transfer may be enabled by providing a wireless power supply interface in place of or in addition to the small battery.

In the above embodiment, the remote control device is used as a device for transmitting control information to the control unit 51, but instead of or in addition to this, a control device connected by wire is used, or the control unit 51. Of course, it can be configured to generate control information by itself.

(Third embodiment)
FIG. 5 is a diagram showing the operating principle of the reaction wheel system according to the third embodiment of the present invention, and FIG. 6 is a perspective view of the reaction wheel system according to the third embodiment of the present invention. The configuration and operating principle of the third embodiment of the present invention will be described with reference to FIGS. 5 and 6. In FIGS. 5 and 6, the parts corresponding to FIGS. 1 to 3 are designated by the same reference numerals, and the description overlapping with the first embodiment and the second embodiment will be omitted.

In this embodiment, the reaction wheels of the two first embodiments are arranged so that the rotation axes of the flywheels of the reaction wheels are coaxial or the directions of the rotation axes are parallel, and are configured as a reaction wheel system. be.

The operating principle of the reaction wheel system of this embodiment is shown in FIG. The reaction wheel system of the present embodiment can generate a rotational movement with respect to a part of the reaction wheel system other than the rotating body or a moving body which is a device in which the reaction wheel system is installed. The case where it is used for the attitude control of the spacecraft will be described. Needless to say, the reaction wheel system of the present embodiment can be used not only for spacecraft but also for attitude control of other devices, and for the reaction wheel system itself as a three-dimensional inverted pendulum or a moving body.

In the reaction wheel system 6 installed in the spacecraft 8, the first flywheel 13 having the same shape and the same moment of inertia, and the reaction wheels 1 and 1'having the second flywheel 13'are the first. The rotation axes of the flywheel 13 and the second flywheel 13'are arranged to be coaxial with each other. When the first flywheel 13 and the second flywheel 13'are rotated in opposite directions at angular velocities having equal absolute values, the angular momentums generated by the respective reaction wheels 1 and 1'cancel each other, and thus the reaction. The angular momentum generated in the wheel system 6 as a whole becomes zero, and no angular momentum is generated in the spacecraft 8.

At the start of the attitude change, the rotation of the first flywheel 13 which is one flywheel is suddenly stopped, and the rotation of the second flywheel 13'which is the other flywheel is continued, so that the spacecraft 8 and the second flywheel An angular momentum exchange is caused with the flywheel 13 of 1, and an angular momentum in the same direction as the rotation direction of the first flywheel 13 is immediately generated in the spacecraft 8, and the spacecraft 8 is rotated. Next, when the spacecraft 8 reaches the target posture, the rotation of the second flywheel 13'is suddenly stopped to cause an angular momentum exchange between the spacecraft 8 and the second flywheel 13', and the space The angular momentum of the second flywheel 13', which is opposite to the angular momentum of the aircraft 8 and has the same magnitude, is added to the moving body, the angular momentum of the spacecraft 8 is offset, and the rotational motion of the spacecraft 8 is immediately performed. It can be stopped. In both the initial state and the final state, the angular momentum of the entire system consisting of the reaction wheels 1 and 1'and the spacecraft 8 is zero, but the difference between the two is that the flywheels 13 and 13'are in the initial state. Is rotating in the opposite direction with the same angular momentum absolute value, whereas in the final state, the rotation of the flywheels 13 and 13'is stopped. With such a configuration, the angular velocity of the rest-to-rest, that is, immediately before the start of the motion and immediately after the end of the motion (immediately before the start of the attitude change and immediately after the end of the attitude change) is set to zero without causing a residual rotation speed. It is possible to change the posture at high speed.

FIG. 6 shows a reaction wheel system 6 according to the present embodiment based on the above operating principle. A description that overlaps with the above operating principle will be omitted. As shown in FIG. 6, the reaction wheel system 6 according to the present embodiment includes a reaction wheel 1, a reaction wheel 1'with the same configuration as the reaction wheel 1, and a control unit 61. The reaction wheel 1 and the reaction wheel 1'are connected by support columns 62, 63, 64, 65 in the rotation axis direction of the flywheels 13, 13'.

The control unit 61 controls the rotational state of each flywheel 13 and 13'by controlling the exciting currents of the motors 14 and 14'of the reaction wheels 1 and 1'and the electromagnets 12 and 12'. Then, in response to a motion start signal input to the control unit 61, which includes information specifying which flywheel to stop the rotation, the rotation of one flywheel is suddenly stopped, and the rotation of the other flywheel is stopped. The rotation of the rotating body is continued, and then the rotation of the other flywheel is suddenly stopped in response to the end-of-motion signal.

Since the reaction wheel of the first embodiment has a small dimension in the rotation axis direction of the flywheel, a compact reaction wheel system can be obtained by configuring the reaction wheel of the first embodiment in which two reaction wheels of the first embodiment are laminated. Can be realized.

In the above embodiment, the first flywheel 13 and the second flywheel 13'have the same shape, have the same moment of inertia, and rotate in opposite directions at angular velocities with the same absolute value. If the signs with the same value generate the opposite angular momentum, but the signs with the same absolute value generate the opposite angular momentum, the moment of inertia and the angular velocity of the first flywheel and the second flywheel It can have any configuration with different absolute values.

Further, in the above embodiment, a reaction wheel pair having two reaction wheels is used, but a reaction wheel system composed of a reaction wheel set of three or more reaction wheels can also be used.

If three or more reaction wheels are configured so that the rotation axes of the respective flywheels are coaxial or the rotation axes are arranged in parallel, the flywheel can have a smaller absolute value of the generated angular momentum. The collision impact between the flywheel and the electromagnet that occurs when stopping can be reduced, and damage to the device can be reduced.

Also, for three or more reaction wheels, the axis of rotation of each flywheel is coaxial or the axis of rotation so that the angular momentum generated by the entire reaction wheel system when all the flywheels are rotating is zero. It can also be configured to be arranged not in parallel.

In the case of a reaction wheel system consisting of a reaction wheel set of three or more reaction wheels, the control unit first rotates the flywheels of the three or more reaction wheels so that their total angular momentum is zero. It then abruptly stops the rotation of one or more, but not all, reaction wheel flywheels in response to a motion start signal containing information specifying which flywheel to stop spinning, and the rest of the reaction wheels. Keep the flywheel spinning. Then, if necessary, the remaining rotating flywheels are suddenly stopped in sequence, and finally, in response to the motion end signal, all rotations of the rotating rotating body are suddenly stopped.

(Fourth Embodiment)
FIG. 7 is a diagram showing the operating principle of the reaction wheel system according to the fourth embodiment of the present invention, and FIG. 8 is a perspective view of the reaction wheel system according to the third embodiment of the present invention. The configuration and operating principle of the fourth embodiment of the present invention will be described with reference to FIGS. 7 and 8. In FIGS. 7 and 8, the parts corresponding to FIGS. 1 to 6 are designated by the same reference numerals, and the description overlapping with the first to third embodiments will be omitted.

In this embodiment, the reaction wheel devices of the two second embodiments are arranged so that the rotation axes of the corresponding flywheels of each axis are coaxial or the directions of the rotation axes are parallel to each other, and are configured as a reaction wheel system. It is a thing. That is, the same mechanism as in the third embodiment is realized as shown in FIG. 8 for each of the three orthogonal axes.

The operating principle of the reaction wheel system of this embodiment is shown in FIG. Similar to the third embodiment, the case where the reaction wheel system is used for the attitude control of the spacecraft will be described as an example. The reaction wheel system 7 includes two reaction wheel devices 5, 5'. The reaction wheel devices 5 and 5'have the same shape and the same moment of inertia for each of the three orthogonal axes, that is, the first flywheel pair 13,13', the second flywheel pair 23, 23', and the second. It has 3 flywheel pairs 33 and 33', and for each flywheel pair, the rotation axes of the flywheels are arranged to be coaxial or parallel to each other.

Therefore, by controlling each reaction wheel pair on the same principle as the reaction wheel system according to the third embodiment, it is possible to control the attitude of the spacecraft for each of the three orthogonal axes. That is, the rest-to-rest high-speed posture can be changed in any direction.

FIG. 8 shows a reaction wheel system 7 according to the present embodiment based on the above operating principle. A description that overlaps with the above operating principle will be omitted. As shown in FIG. 8, the reaction wheel system 7 according to the present embodiment includes a reaction wheel device 5, a reaction wheel device 5', and a remote control device 71.

The remote control device 71 transmits various control signals to the control units 51, 51'to the wireless communication units 53, 53' provided in the reaction wheel devices 5, 5'. Various control signals include an exercise start signal and an exercise end signal. The motion start signal can include, for example, information that specifies which flywheel pair of which flywheel to stop rotation, which will be described later. The control units 51 and 51'of the reaction wheel devices 5 and 5'have a first flywheel pair 13 and 13'and a second flywheel pair 23 and 23'based on the control information received from the remote control device 71. ', Control the rotational state of the third flywheel pair 33, 33'. Then, in response to the motion start signal received from the remote control device 71, the rotation of one flywheel of the flywheel pair designated by the motion start signal is suddenly stopped, and the rotation of the rotating body of the other flywheel is continued. Then, in response to the motion end signal received from the remote control device 71, the rotation of the other flywheel is suddenly stopped.

Although the present invention has been described above with respect to some embodiments for illustration purposes, the present invention is not limited thereto, and the embodiments and details are described without departing from the scope and spirit of the present invention. It will be apparent to those skilled in the art that various modifications and modifications can be made.

1 Reaction wheel 10 Frame 101 First frame part 102 Second frame part 103 Hole 11 Leaf spring 111 First slit 112 First elasticity applying part 113 Second slit 114 Second elasticity applying part 12 Electromagnet 121 First 1 Braking surface 13 Flywheel (1st flywheel)
131 Main body 131a Recess 132 Spoke 133 Hole 134 Second braking surface 14 Motor 141 Motor body 141a Bearing 143 Shaft 15 Support pillar 16 Support arm 17 Motor mount 171 Hole 18 Connecting member 181 Cylindrical part 182 Flange part 183 Convex part 184 Spoke screw 191 Washer 192 Spring 193 Screw 194 Spoke member 195 Bearing 2 Reaction wheel 20 Frame 3 Reaction wheel 30 Frame 40 Frame 41 Frame 42 Frame 43 Frame 5 Reaction wheel device 51 Control unit 521 MEMS sensor IMU
524 MEMS sensor IMU
525 MEMS sensor IMU
526 MEMS sensor IMU
527 MEMS sensor IMU
528 MEMS sensor IMU
53 Wireless communication unit 54 Power supply 551 Bracket 552 Bracket 555 Bracket 554 Bracket 555 Bracket 556 Bracket 557 Bracket 558 Bracket 6 Reaction wheel system 61 Control unit 62 Support pillar 63 Support pillar 64 Support pillar 65 Support pillar 7 Reaction wheel system 71 Remote control device 8 Spacecraft 1'Reaction wheel 10'Frame 12'Electromagnet 13'Second flywheel 901 Rotating body 902 Armature 903 Bouncer 905 Electromagnet 911 Servo motor 912 Arm 913 Brake pad 914 Flywheel 915 Protrusion

Claims (8)

With the frame
A flywheel placed facing the frame and
An electromagnet having a ring-shaped or arc-shaped shape arranged between the frame and the flywheel,
An urging member attached to the frame and urging the electromagnet to the frame side,
Equipped with
At least a portion of the flywheel facing the electromagnet is formed of a ferromagnetic material having recesses that can accommodate at least a portion of the electromagnet.
The electromagnet is urged by the urging member so that the electromagnet and the flywheel are separated from each other when the electromagnet is not excited.
A reaction wheel that generates torque by stopping the flywheel by contacting the concave portion of the flywheel against the urging force of the urging member when the electromagnet is excited. The reaction wheel according to claim 1, wherein the surface of the electromagnet that contacts the flywheel when the electromagnet is excited and the surface of the flywheel that contacts the flywheel when the electromagnet is excited have complementary shapes. The reaction wheel according to claim 1 or 2, wherein the urging member is a leaf spring. The reaction wheel according to any one of claims 1 to 3 , wherein a portion of the flywheel other than the portion on the side facing the electromagnet is formed of a material having a higher density than the ferromagnetic material. Two or more reaction wheels according to any one of claims 1 to 4 , and the reaction wheel.
A control unit that controls the excitation state of each of the electromagnets of the two or more reaction wheels, and
Equipped with
The two or more reaction wheels are reaction wheel devices in which the directions of the rotation axes of the flywheels of the two or more reaction wheels are different from each other. The two or more reaction wheels are three reaction wheels.
The reaction wheel device according to claim 5 , wherein the three reaction wheels are arranged so that the rotation axes of the flywheels of the three reaction wheels are orthogonal to each other. The reaction wheel device according to claim 6 , wherein the shapes of the frames of the three reaction wheels are the same square shape. The reaction wheel device according to any one of claims 5 to 7 , wherein a chamfered portion is formed on one end side in the axial direction of the outer peripheral surface of the flywheel of each of the two or more reaction wheels.

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