A spherical capsule robot driven by pure magnetic moment differential

Abstract

A pure magnetic moment differential drive spherical capsule robot. By controlling the axis orientation of the external rotating magnetic field, the attitude stability of the pan-tilt camera during fixed-point observation of the capsule and the rolling movement of the capsule when the observation position is changed can be achieved, and the automatic clutch structure can reliably ensure the stable operation and mutual conversion of the two working modes of the capsule. When the capsule is fixed-point observation, the reliable separation of the automatic clutch mechanism can enable the differential gyro system of the capsule to rotate independently around its central axis. The gyroscopic effect generated by the rotation of the differential gyro system can ensure the stability of the picture taken by the capsule pan-tilt camera. When the capsule is rolling, the reliable locking of its internal automatic clutch structure can ensure that the capsule shell rotates together with its internal differential gyro system, thereby realizing the rolling movement of the capsule. The spherical capsule of the present invention has the advantages of compact structure, high reliability, good stability, flexible capsule attitude control, and the ability to separate the two working modes of capsule attitude adjustment and rolling movement.

Description

Technical Field

[0001] The present invention belongs to the field of automation engineering technology and relates to an innovative structural design of a pure magnetic moment driven spherical capsule robot with a differential gyro transmission structure. The capsule can achieve omnidirectional fixed-point observation and rolling walking functions by changing its posture. Background Art

[0002] Capsule endoscopes are commonly used for gastrointestinal lesion examinations. However, due to the limited environment within the gastrointestinal tract, controlling and moving capsule endoscopes is challenging. Currently, mainstream capsule endoscopes lack a motion mechanism and can only move forward through intestinal peristalsis. This uncontrollable position and direction results in inefficient pathology screening. Currently, there are two main approaches to autonomously propelled capsule endoscopes. The first involves integrating a drive or micromotor into the capsule, powered by a tow cable or battery, and leveraging the capsule's propulsion mechanism for active motion. However, due to the limited size of capsule endoscopes (approximately 13 mm in diameter and 25 mm in length), the limited volume within the capsule not only makes system integration and miniaturization challenging, but also the integrated microbattery cannot fully guarantee the system's energy supply. The second approach uses an external magnetic source as the external drive and a permanent magnet built into the capsule as the internal drive. Active motion is achieved through a magnetic link between the internal and external drives. These types of capsules are collectively referred to as magnetically driven capsules. According to different working principles, magnetically driven capsules can be divided into magnetic resonance type, magnetic drag type, magnetic force and magnetic moment hybrid drive type, and pure magnetic moment drive type.

[0003] Magnetic resonance capsule robots use an external resonant magnetic field to drive a permanent magnet or eccentric mass inside the capsule to generate a driving force. Although magnetic resonance capsules can achieve active locomotion, the fundamental magnetic field generated by the magnetic resonance system is fixed in direction, making it impossible for the drive system to control the direction of the magnetic object, thus limiting the feasibility of this type of capsule robot in clinical applications. Magnetic drag capsules use the magnetic attraction generated by an external permanent magnet, an electromagnetic coil, and an embedded permanent magnet to drag the capsule. This drive method offers the advantages of a simple drive principle, easy operation, and low cost. However, the gradient magnetic field decays rapidly in space, and the field strength exhibits a nonlinear relationship with distance, making it difficult to generate a controlled gradient magnetic field over a large range. Magnetic force and magnetic torque hybrid drive capsules use the magnetic attraction generated by an external electromagnetic device and an embedded permanent magnet to drag the capsule forward, and the static magnetic torque between them controls the capsule's direction. Compared to magnetically driven capsules, this method not only achieves active capsule motion but also effectively controls the capsule's orientation. However, this drive method suffers from the coupling problem between magnetic force and magnetic moment. When controlling the capsule's position through magnetic force or orientation through magnetic moment, the two operations inevitably interfere with each other. Therefore, achieving precise control of the capsule's position and orientation using this drive method is quite difficult.

[0004] A typical representative of pure magnetic moment-driven capsules is the spiral capsule robot, which often has a radially magnetized permanent magnet embedded in it and is driven by an external rotating magnetic field. Spiral capsule robots mostly work in a viscous working environment filled with fluid. When the capsule rotates around its own axis, it can displace the liquid backwards through the spiral ribs distributed on its surface, thereby converting the capsule's rotational motion into linear motion, thereby achieving active walking. Compared with magnetic drag under a gradient magnetic field, pure magnetic moment drive under a uniform magnetic field environment can avoid the coupling problem of magnetic force and magnetic moment, and the capsule has better controllability and higher motion accuracy. However, spiral-driven capsules can only adapt to tubular environments filled with liquid and are generally not applicable to three-dimensional spacious environments such as the gastrointestinal colon. At the same time, the spiral drive method can easily cause sprains or scratches to the intestines.

[0005] In summary, although many researchers have developed capsule robots based on various drive principles and achieved active motion, existing capsule structures and drive principles make it difficult to precisely control their posture and position, failing to meet the practical medical needs of omnidirectional, fixed-point observation and movement within the human gastrointestinal tract. Therefore, research into the motion principles and structural schemes of new active capsules, and achieving effective control of their posture and position, is a key development direction for capsule robots.

[0006] In response to the above problems, the present invention proposes a pure magnetic torque driven spherical capsule robot with a differential gyro mechanism, which can realize the functions of omnidirectional fixed-point observation and rolling walking. When the capsule is observing at a fixed point, the reliable separation of the automatic clutch mechanism can enable the capsule's differential gyro system to rotate independently around its central axis. The gyroscopic effect generated by the rotation of the differential gyro system can ensure the stability of the image captured by the capsule's pan-tilt camera. When the capsule is rolling, the reliable locking of its internal automatic clutch structure can ensure that the capsule shell rotates together with its internal differential gyro system, thereby realizing the rolling walking of the capsule. By controlling the axis orientation of the external rotating magnetic field, the capsule's posture can be effectively controlled, thereby realizing the mutual conversion between the capsule's omnidirectional fixed-point observation and rolling walking functions.

[0007] The pure magnetic moment-driven spherical capsule proposed in the present invention can solve the difficulties in posture control of magnetically driven capsules and the problems of magnetic force and magnetic moment coupling. The proposed spherical capsule has high posture controllability, good motion stability and flexibility, and is expected to solve the technical bottleneck that restricts the large-scale clinical promotion and application of magnetic-driven capsule robots. Summary of the Invention

[0008] This invention addresses the challenges of existing magnetic capsule robots, such as difficulty in posture control, poor stability and flexibility, and susceptibility to gastrointestinal impact. By designing a spherical capsule robot with a differential gyroscopic drive mechanism driven by a uniform rotating magnetic field, this invention integrates a differential drive mechanism, a gyroscopic mechanism, an automatic clutch structure, and pure magnetic torque drive technology. The resulting spherical capsule robot is capable of flexibly and reliably achieving fixed-point posture adjustment and rolling motion within the three-dimensional, flexible environment of the human stomach and colon.

[0009] The technical solution of the present invention:

[0010] A pure magnetic moment differential drive spherical capsule robot, wherein the external drive source of the spherical capsule robot is a spatial universal uniform rotating magnetic field generated by a three-axis Helmholtz coil, and the internal drive source is a radially magnetized Nd-Fe-B permanent magnet embedded in the capsule; the outer shell of the pure magnetic moment differential drive spherical capsule robot is spherical, with a raised transparent dome at one end of the sphere, and a camera module installed in the transparent dome; the pure magnetic moment differential drive spherical capsule robot mainly consists of a differential gyroscope system, a pan-tilt camera system and an automatic clutch mechanism; when the pure magnetic moment differential drive spherical capsule robot is performing fixed-point observation, the internal differential gyroscope system is used to ensure the stability of the pan-tilt camera system, and by changing the axial orientation of the spatial universal uniform rotating magnetic field, the pan-tilt camera system follows the magnetic field axis to change the observation orientation or observation position; the automatic clutch mechanism is used to achieve the separation of the pan-tilt camera system and the rotating flange when the pure magnetic moment differential drive spherical capsule robot is performing fixed-point observation, and to lock the pan-tilt camera system and the rotating flange when the capsule is rolling;

[0011] The differential gyro system mainly consists of a flange 7, an Nd-Fe-B permanent magnet 8, a miniature bearing 9, a bevel gear 10, a center shaft bevel gear (the bevel gear and the center shaft form a gear shaft) 11, a barrel bevel gear (the bevel gear and the center shaft form a gear shaft) 12, a miniature ceramic ball bearing 13 and a ceramic bearing 14. Among them, the Nd-Fe-B permanent magnet 8 is connected to the flange 7 by interference fit, and the flange 7 is connected to the barrel bevel gear 12 by rotation through the ceramic bearing 14. A pair of bevel gears 10 are installed at the bottom of the flange 7. The bevel gears 1 0 is connected to the flange 7 in rotation through the micro bearing 9; the barrel bevel gear 12 is mounted on the central shaft bevel gear 11 through the micro ceramic ball bearing 13 and forms an interference fit with the inner ring of the ceramic bearing 14; the central shaft bevel gear 11 is fixed to the bottom of the lower spherical shell 16 and is located on the central axis of the pure magnetic moment differential drive spherical capsule robot; when the flange 7 rotates, the two bevel gears 10 installed at the bottom of the flange 7 can drive the barrel bevel gear 12 and the central shaft bevel gear 11 to rotate, and the bevel gear 10 installed at the bottom of the flange 7 and the central shaft The bevel gear 11 and the barrel bevel gear 12 constitute a differential, the power source of which is the radially magnetized Nd-Fe-B permanent magnet 8; when the axis of the spherical capsule robot is in a vertical position but not limited to completely vertical, the external uniform rotating magnetic field can drive the flange 7 to rotate around the barrel bevel gear 12 through the radially magnetized Nd-Fe-B permanent magnet 8; the bevel gear (10) installed on the flange (7) can directly drive the barrel bevel gear (12) to rotate around the central axis bevel gear (11), and the central axis bevel gear 1 meshed with the bevel gear 10 1, no rotation occurs. This phenomenon occurs because the spherical shell, fixedly connected to the central bevel gear 11, contacts the viscoelastic gastrointestinal tract below it and is therefore subject to a viscoelastic frictional damping torque. However, the barrel-shaped bevel gear 12, meshing with the bevel gear 10, experiences only the frictional torque between the bearing balls and the raceway, which is much smaller than the frictional torque between the capsule and the gastrointestinal tract. According to the principle of minimum energy consumption, the barrel-shaped bevel gear 12 will experience "idle rotation" similar to car wheel slippage, while the lower spherical shell 16, fixedly connected to the central bevel gear 11, will not rotate. Therefore, the Nd-Fe-B permanent magnet 8, flange 7, the pair of bevel gears 10, and the meshing barrel-shaped bevel gear 12 and central bevel gear 11 form a differential gyroscopic system. At this point, the pair of bevel gears 10 mounted on flange 7 both orbit around the central bevel gear 11 and rotate about their own axes. When the spherical capsule robot is observing at a fixed point, the flange 7, the pair of bevel gears 10 and the barrel-shaped bevel gear 12 rotate at high speed around the central axis bevel gear 11. The gyroscopic effect generated by them can ensure the stability of the central axis bevel gear 11. The central axis bevel gear 11 is firmly connected to the camera of the pan-tilt head 5, so the capsule shooting picture can be kept stable.

[0012] The pan-tilt camera system is mainly composed of a transparent dome 1, a camera module 2, a micro battery 3, a wireless transmitter module 4 and a pan-tilt 5; wherein the camera module 2, the micro battery 3, and the wireless transmitter module 4 constitute a wireless image transmission module, and the wireless image transmission module is fixed in position through the pan-tilt 5 and the center hole on the transparent dome 1; the pan-tilt 5 is fixedly connected to the upper spherical shell 15 through four buckles evenly distributed circumferentially, and is interference-connected with the center axis bevel gear 11 through the center hole at the bottom; there is a gap between the pan-tilt 5 and the flange 7 in the axial direction, and the spherical capsule robot is in a When in a vertical position (but not limited to a completely vertical position), flange 7 and pan-tilt head 5 are separated, allowing relative rotation between them. When the spherical capsule robot's axis is in a horizontal position (but not limited to a completely horizontal position), flange 7 and pan-tilt head 5 are locked, preventing relative rotation between them. The bottom protrusion of pan-tilt head 5 mates with the inner ring end face of micro-ceramic ball bearing 13 to achieve axial positioning of micro-ceramic ball bearing 13. When the spherical capsule robot's axis is in a vertical position (but not limited to a completely vertical position), camera module 2 can photograph and record the target area through transparent dome 1. Because the pan-tilt head camera does not rotate with the differential gyro system, the gyroscopic effect generated by the differential gyro system's rotation maintains the stability of pan-tilt head 5, thus ensuring the stability of gastrointestinal imaging.

[0013] The automatic clutch mechanism is mainly composed of a spherical pit on the pan-tilt head 5, a small ball 6 and a cylindrical raceway 17 on the flange 7. There is a fitting clearance between the pan-tilt head 5 and the flange 7 along the direction of the central axis bevel gear 11; the diameter of the spherical pit on the pan-tilt head 5 is the same as the diameter of the small ball 6, and the diameter of the inclined cylindrical raceway 17 on the flange 7 is larger than the diameter of the small ball 6. The small ball 6 can roll freely in the inclined cylindrical raceway 17, and the center axis of the cylindrical raceway 17 passes through the center of the spherical pit on the pan-tilt head 5; 4 groups of evenly distributed automatic clutch mechanisms are arranged inside the spherical capsule robot; when the axis of the spherical capsule robot is in a vertical position but not limited to completely vertical, the small ball 6 moves to the bottom of the inclined cylindrical raceway 17 on the flange 7 under the action of gravity, and the automatic clutch mechanism is in a disengaged state at this time; when the axis of the spherical capsule robot is in a horizontal position, The clutch structure can be automatically locked; among the four groups of clutches evenly distributed inside the spherical capsule robot, the small ball 6 in the automatic clutch mechanism in the middle and lower positions will roll downward along the track under the action of gravity until it contacts the spherical pit on the pan-tilt head 5; at this time, half of the small ball 6 is stuck in the inclined cylindrical raceway 17 on the flange 7, and half is stuck in the spherical pit of the pan-tilt head 5; by shearing the small ball 6, the rotating flange 7 can drive the pan-tilt head 5 to rotate, and since the pan-tilt head 5 is fixedly connected to the upper spherical shell 15, it can drive the spherical capsule robot to roll; even if the small ball 6 initially located below the spherical capsule robot moves to the upper side during the rolling process of the spherical capsule robot, since the spherical pit on the pan-tilt head 5 can effectively hold the small ball 6, and the flange 7 has a tendency to press the small ball 6 into the groove of the pan-tilt head 5 during the process of shearing the small ball 6, the effective engagement of the small ball 6 is guaranteed.

[0014] Beneficial effects of the present invention: The present invention integrates a differential structure, gyro stabilization technology, and an automatic clutch mechanism into the structural design of a pure magnetic torque-driven spherical capsule robot. By controlling the axis orientation of the external rotating magnetic field, the attitude stability of the pan-tilt camera during fixed-point observation of the capsule and the rolling movement of the capsule when the observation position is changed are achieved, and the automatic clutch structure can reliably ensure the stable operation and mutual conversion of the two working modes of the capsule. When the capsule is fixed-point observation, the independent rotation of its differential gyro system around its central axis effectively prevents the generation of rotating images and provides technical support for the shooting of stable images by the pan-tilt camera. When the capsule is rolling, the reliable locking of its automatic clutch mechanism meets the working requirements of the capsule changing its observation position with the external rotating magnetic field. The capsule designed by the present invention has the advantages of compact structure, high reliability, good stability, flexible capsule attitude control, and the ability to separate the two working modes of capsule attitude adjustment and rolling movement. It effectively overcomes the shortcomings of traditional magnetic-driven capsules such as difficult attitude control, poor stability and maneuverability, and can provide strong technical support for the large-scale promotion of magnetic-driven capsules. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] Figure 1a This is the overall appearance of the spherical capsule robot.

[0016] Figure 1b This is a cross-sectional view of the spherical capsule robot.

[0017] Figure 2 This is a schematic diagram of the spherical capsule gimbal camera system.

[0018] Figure 3 This is the principle diagram of the spherical capsule differential gyroscope system.

[0019] Figure 4 This is the schematic diagram of the spherical capsule automatic clutch system.

[0020] Figure 5 It is a schematic diagram of the all-round observation and rolling movement of the spherical capsule in the stomach.

[0021] In the figure: 1 transparent dome; 2 camera module; 3 micro battery; 4 wireless transmitter module; 5 pan / tilt; 6 small ball bearing; 7 flange; 8 Nd-Fe-B permanent magnet; 9 micro bearing; 10 bevel gear; 11 center shaft bevel gear; 12 barrel bevel gear; 13 micro ceramic ball bearing; 14 ceramic bearing; 15 upper spherical shell; 16 lower spherical shell; 17 cylindrical raceway. DETAILED DESCRIPTION

[0022] The structural design scheme and specific embodiments proposed in the present invention are further explained below with reference to the accompanying drawings and specific implementation methods.

[0023] As attached Figure 1a and Figure 1b As shown, the capsule robot proposed in this invention has an overall spherical appearance, with a miniature transparent dome protruding from the end housing the camera. The transparent dome 1 and the upper spherical shell 15 have an interference fit, while the lower spherical shell 16 and the upper spherical shell 15 are joined by an annular snap fastener to form a complete sphere. The pure magnetic torque-driven spherical capsule robot described in this invention primarily consists of three components: a pan-tilt camera system, a differential gyroscope system, and an automatic clutch mechanism.

[0024] As attached Figure 2As shown, the pan-tilt camera system primarily consists of a transparent dome 1, a camera module 2, a micro battery 3, a wireless transmitter module 4, a pan-tilt 5, a central axis bevel gear 11, an upper spherical shell 15, and a lower spherical shell 16. The camera module 2, micro battery 3, and wireless transmitter module 4 constitute the wireless image transmission module, which is secured in place by the pan-tilt 5 and the center hole in the transparent dome 1. The pan-tilt 5 is fixedly connected to the upper spherical shell 15 via four circumferentially distributed snaps and forms an interference fit with the central axis bevel gear 11 via the center hole below. A clearance exists between the pan-tilt 5 and the flange 7 along the axis. When the spherical capsule robot is in a vertical position (but not limited to a completely vertical position), the flange 7 and pan-tilt 5 are separated and can rotate relative to each other. When the axis of the spherical capsule robot is in a horizontal position (but not limited to a completely horizontal position), the flange 7 and pan-tilt 5 are locked and cannot rotate relative to each other. The bottom protrusion of the pan-tilt 5 mates with the inner ring end face of the micro ceramic ball bearing 13 to ensure axial positioning of the micro ceramic ball bearing 13.

[0025] As attached Figure 3As shown, the differential gyro system of the spherical capsule described in the present invention primarily consists of a flange 7, an Nd-Fe-B permanent magnet 8, a miniature bearing 9, a bevel gear 10, a central axis bevel gear 11, a barrel bevel gear 12, a miniature ceramic ball bearing 13, and a ceramic bearing 14. The Nd-Fe-B permanent magnet 8 is interference-connected to the flange 7. The flange 7 is rotationally connected to the barrel bevel gear 12 via the ceramic bearing 14. A pair of bevel gears 10 are mounted at the bottom of the flange 7, which is rotationally connected to the flange 7 via the miniature bearing 9. The barrel bevel gear 12 is mounted on the central axis bevel gear 11 via the miniature ceramic ball bearing 13 and forms an interference fit with the inner ring of the ceramic bearing 14. When the axis of the spherical capsule robot is in a vertical position (but not limited to a completely vertical position), an external uniform rotating magnetic field can drive the flange 7 to rotate about the axis of the barrel bevel gear 12 via the radially magnetized Nd-Fe-B permanent magnet 8. Bevel gear 10 mounted on flange 7, through a gear pair, drives barrel-shaped bevel gear 12 to rotate around central bevel gear 11. However, central bevel gear 11, meshed with bevel gear 10, does not rotate. This phenomenon occurs because lower spherical shell 16, fixedly connected to central bevel gear 11, contacts the viscoelastic gastrointestinal tract below and is therefore subject to a viscoelastic friction damping torque. However, barrel-shaped bevel gear 12, meshed with bevel gear 10, is only subject to the friction torque between the bearing balls and the raceway, which is much smaller than the friction torque between the capsule and the gastrointestinal tract. According to the principle of minimum energy consumption, barrel-shaped bevel gear 12 will produce "idle rotation" similar to car wheel slippage, while lower spherical shell 16, fixedly connected to central bevel gear 11, does not rotate. Because the differential gyro system's rotation around the capsule's central axis maintains the stability of its central axis, the stability of the gimbal camera mounted on central bevel gear 11 is guaranteed. At this time, the bevel gear 10 generates both orbital revolution around the central axis bevel gear 11 and rotation along its own axis.

[0026] As attached Figure 4 As shown in FIG, the automatic clutch mechanism of the spherical capsule of the present invention is mainly composed of small balls 6, cylindrical raceways 17 on flange 7 and spherical pits on pan-tilt head 5. There are 4 groups of evenly distributed automatic clutch mechanisms inside the capsule. Figure 1b As shown in FIG, when the capsule axis is in a vertical position but not limited to completely vertical, the small ball 6 moves to the bottom of the cylindrical raceway on the flange 7 under the action of gravity, and the automatic clutch mechanism is in a disengaged state. Figure 4As shown, when the capsule axis is in a horizontal position, the clutch structure can be automatically locked. Among the four groups of clutches evenly distributed inside the capsule, the small ball 6 in the automatic clutch mechanism in the middle and lower positions will roll down along the track under the action of gravity until it contacts the spherical pit on the pan-tilt head 5. At this time, half of the small ball 6 is stuck in the cylindrical raceway 17 on the flange 7, and half is stuck in the spherical groove of the pan-tilt head 5. By shearing the small ball 6, the rotating flange 7 can drive the pan-tilt head 5 to rotate, and since the pan-tilt head 5 is fixedly connected to the upper spherical shell 15, it can drive the capsule to roll. Even if the ball initially located below the capsule moves to the top during the rolling process of the capsule, since the spherical pit on the pan-tilt head 5 can effectively hold the small ball 6, and the flange 7 has a tendency to press it into the groove of the pan-tilt head 5 during the process of shearing the small ball 6, the effective engagement of the small ball 6 can be guaranteed. At the same time, during the rolling process, at least one of the four evenly distributed clutch structures in the capsule is located in the middle and lower position, thereby ensuring reliable locking of the clutch mechanism.

[0027] Example:

[0028] The following takes the inspection process of a spherical capsule in the human stomach as an example to introduce its specific workflow. Figure 5 As shown in the figure, after the spherical capsule is swallowed and enters the human stomach cavity, the capsule robot can realize the omnidirectional fixed-point observation function and rolling walking function by adjusting the axis orientation of the external rotating magnetic field.

[0029] As attached Figure 1b As shown, when the capsule axis is in a vertical position but not limited to completely vertical, the small ball 6 in the automatic clutch mechanism will move to the bottom of the cylindrical raceway 17 on the flange under the action of gravity, and the flange 7 and the pan-tilt head 5 are separated. The external uniform rotating magnetic field can drive the differential gyroscope system to rotate around the capsule center axis bevel gear 11, and the pan-tilt head camera fixedly connected to the capsule center axis bevel gear 11 can keep its axis stable, thereby ensuring the stability of the capsule shooting picture. When the capsule needs to change the observation orientation, by controlling the change in the axis orientation of the external uniform rotating magnetic field, the coupling magnetic moment between the external magnetic field and the radially magnetized Nd-Fe-B permanent magnet 8 embedded in the capsule can drive the capsule to change its axis orientation, and with the help of the capsule's pan-tilt head camera system, the area of interest can be repeatedly observed. As shown in the attached figure Figure 5 As shown, when the capsule is observed at position A2, the axis of the rotating magnetic field is controlled to be at positions n2, n3 and n4 respectively, and the capsule axis n f You can follow the magnetic field axis to reach n f2 、n f3 and n f4 position, thereby achieving all-round fixed-point observation at position A2.

[0030] As attached Figure 4As shown, when the capsule needs to change its observation position, its rolling movement can be achieved by adjusting the capsule axis to the horizontal direction. Specifically, the characteristic that the capsule axis can continuously change its orientation following the axis of the external magnetic field can be used. After the orientation of the rotating magnetic field axis is adjusted from a non-horizontal position to a horizontal position, the small ball 6 in the automatic clutch mechanism in the lower middle part of the capsule will roll to a position in contact with the spherical groove on the pan-tilt head 5 under the action of gravity. At this time, the small ball will be half stuck in the spherical groove on the pan-tilt head and half stuck in the cylindrical raceway on the flange, and the rotating flange has a tendency to press the small ball against the side wall. Therefore, the rotating flange 7 will drive the capsule shell fixed to the pan-tilt head 5 to rotate, thereby achieving the rolling movement of the capsule. As shown in the attached figure Figure 5 As shown, when the spherical capsule is to be moved from position A1 to position A2, or from position A2 to position A3, the axis of the rotating magnetic field can be adjusted to position n1 and position n5 respectively. The capsule axis n f It can follow n1 to reach the horizontal position, and the rotating magnetic field can drive the capsule to roll and walk, thereby realizing the change of the observation position.

Claims

1. A pure magnetic moment differential drive spherical capsule robot, characterized in that: The external driving source of the pure magnetic moment differential drive spherical capsule robot is the spatial universal uniform rotating magnetic field generated by the three-axis Helmholtz coil, and the internal driving source is the radially magnetized Nd-Fe-B permanent magnet embedded in the capsule; the outer shell of the pure magnetic moment differential drive spherical capsule robot is spherical, and one end of the sphere is a raised transparent dome, and the transparent dome is equipped with a camera module; the pure magnetic moment differential drive spherical capsule robot is mainly composed of a differential gyroscope system, a pan-tilt camera system and an automatic clutch mechanism; when the pure magnetic moment differential drive spherical capsule robot is performing fixed-point observation, the internal differential gyroscope system is used to ensure the stability of the pan-tilt camera system, and by changing the axial orientation of the spatial universal uniform rotating magnetic field, the pan-tilt camera system follows the magnetic field axis to change the observation orientation or observation position; the automatic clutch mechanism is used to realize the separation of the pan-tilt camera system and the rotating flange when the pure magnetic moment differential drive spherical capsule robot is performing fixed-point observation, and the locking of the pan-tilt camera system and the rotating flange when the capsule is rolling; The differential gyro system mainly consists of a flange (7), an Nd-Fe-B permanent magnet (8), a miniature bearing (9), a bevel gear (10), a central shaft bevel gear (11), a barrel bevel gear (12), a miniature ceramic ball bearing (13) and a ceramic bearing (14); wherein the Nd-Fe-B permanent magnet (8) is interference-connected to the flange (7), and the flange (7) is connected to the barrel bevel gear (12) in a rotational manner through the ceramic bearing (14); a pair of bevel gears (10) is installed at the bottom of the flange (7), and the pair of bevel gears (10) is connected to the flange (7) in a rotational manner through the miniature bearing (9); the barrel bevel gear (12) is installed on the central shaft bevel gear (11) through the miniature ceramic ball bearing (13) and forms an interference fit with the inner ring of the ceramic bearing (14); the central shaft bevel gear (11) is fixed on the bottom of the lower spherical shell (16) and is located in the pure magnetic moment differential drive. The flange (7) is mounted on the central axis of the spherical capsule robot; when the flange (7) rotates, the two bevel gears (10) installed at the bottom thereof can drive the barrel bevel gear (12) and the center shaft bevel gear (11) meshed therewith to rotate, and the bevel gear (10) installed at the bottom of the flange (7), the center shaft bevel gear (11) and the barrel bevel gear (12) constitute a differential, the power source of which is a radially magnetized Nd-Fe-B permanent magnet (8); when the axis of the spherical capsule robot is in a vertical position but not limited to being completely vertical, the external uniform rotating magnetic field can drive the flange (7) to rotate around the barrel bevel gear (12) through the radially magnetized Nd-Fe-B permanent magnet (8); the bevel gear (10) installed on the flange (7) can directly drive the barrel bevel gear (12) to rotate around the center shaft bevel gear (11), while the center shaft bevel gear (11) meshed with the bevel gear (10) does not rotate; The pan-tilt camera system is mainly composed of a transparent dome (1), a camera module (2), a micro battery (3), a wireless transmitter module (4) and a pan-tilt (5); wherein the camera module (2), the micro battery (3) and the wireless transmitter module (4) constitute a wireless image transmission module, and the wireless image transmission module is fixed in position through the pan-tilt (5) and the center hole on the transparent dome (1); the pan-tilt (5) is fixedly connected to the upper spherical shell (15) through four buckles evenly distributed in the circumference, and is connected to the central axis bevel gear (11) through the center hole at the bottom. An interference fit connection is formed; there is a gap between the pan-tilt platform (5) and the flange (7) in the axial direction; when the spherical capsule robot is in a vertical position but not limited to a completely vertical position, the flange (7) and the pan-tilt platform (5) are in a separated state, and there is relative rotation between the two; when the axis of the spherical capsule robot is in a horizontal position but not limited to a completely horizontal position, the flange (7) and the pan-tilt platform (5) are in a locked state, and there is no relative rotation between the two; the bottom protrusion of the pan-tilt platform (5) cooperates with the inner ring end face of the micro ceramic ball bearing (13) to achieve axial positioning of the micro ceramic ball bearing (13); The automatic clutch mechanism is mainly composed of a spherical pit on the platform (5), a small ball (6) and a cylindrical raceway (17) on the flange (7). There is a matching clearance between the platform (5) and the flange (7) along the direction of the central axis bevel gear (11); the diameter of the spherical pit on the platform (5) is the same as the diameter of the small ball (6), the diameter of the inclined cylindrical raceway (17) on the flange (7) is larger than the diameter of the small ball (6), and the small ball (6) can be rotated in the inclined cylindrical raceway (17). 7) and the central axis of the cylindrical roller (17) passes through the center of the spherical pit on the pan-tilt (5); 4 groups of evenly distributed automatic clutch mechanisms are arranged inside the spherical capsule robot; when the axis of the spherical capsule robot is in a vertical position but not limited to completely vertical, the small ball (6) moves to the bottom of the inclined cylindrical roller (17) on the flange (7) under the action of gravity, and the automatic clutch mechanism is in a disengaged state at this time; when the axis of the spherical capsule robot is in a horizontal position, the clutch structure can be automatically locked; among the 4 groups of evenly distributed clutches inside the spherical capsule robot, the small ball (6) in the automatic clutch mechanism at the middle and lower positions will roll down along the track under the action of gravity until it contacts the spherical pit on the pan-tilt (5); at this time, half of the small ball (6) is stuck in the inclined cylindrical roller (17) on the flange (7), and the other half is stuck in the spherical pit of the pan-tilt (5); by shearing the small ball (6), the rotating flange (7) can drive the pan-tilt (5) rotates, and since the platform (5) is fixedly connected to the upper spherical shell (15), it can drive the spherical capsule robot to roll; even if the small ball (6) initially located below the spherical capsule robot moves to the upper part during the rolling process of the spherical capsule robot, since the spherical pit on the platform (5) can effectively hold the small ball (6), and the flange (7) has a tendency to press the small ball (6) into the groove of the platform (5) during the process of shearing the small ball (6), the effective engagement of the small ball (6) is guaranteed.

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