A kind of articulated arm and control method thereof

Abstract

The present invention provides a joint arm, comprising a first driving part, a second driving part, a rotating part and a driving plate, wherein the first driving part is a hollow structure, a first motor is arranged inside the first driving part, a rotor of the first motor can rotate around a first axis, the rotating part is fixedly connected to a first flange end face of the first driving part, and can rotate around the first axis with the first flange, the second driving part is arranged above the first driving part, the output shaft of the second driving part passes through the hollow structure of the first driving part and is connected to a first bevel gear in the rotating part, and can drive a permanent magnet assembly in the rotating part to rotate around a second axis perpendicular to the first axis. The joint arm disclosed by the present invention adopts a motor to be superimposed and installed at a fixed position on the top, which reduces the turning radius to the maximum extent, and cancels the electric slip ring device, so the appearance is simple, the volume and turning radius are small, and the reliability is high.

Description

Technical Field

[0001] The present invention relates to the field of medical devices, and in particular to an articulated arm and a control method thereof. Background Art

[0002] At present, the use of capsule endoscopes to examine the human digestive tract is gradually becoming a new trend. Compared with traditional intubation electronic endoscopes, capsule endoscopes are more convenient and comfortable. The examinee only needs to swallow a capsule-pill-sized electronic camera device to conduct a comprehensive examination of the entire digestive tract without causing physical discomfort to the examinee and reducing the risk of cross-infection.

[0003] When using the magnetically controlled capsule gastroscopy system to examine the human stomach, after swallowing the capsule endoscope, it is necessary to use a magnetically controlled device outside the human body to use the external magnetic field to exert force on the small magnets inside the capsule endoscope to control the posture and position of the capsule endoscope, so as to conduct a full-range inspection of the entire gastric cavity wall.

[0004] The magnetic control device in the external magnetic control equipment must meet the requirement of being able to control the large magnet to rotate arbitrarily along two mutually perpendicular rotation axes. At the same time, when the subject is lying on the hospital bed for gastroscopy, the magnetic control device will move and operate back and forth above the human body. If the magnetic control device is large in size, it will cause a sense of oppression and discomfort to the subject visually and psychologically.

[0005] The magnetron devices disclosed in Chinese patent publications CN111643039A and CN111657826A adopt the traditional design concept, that is, two motors are respectively installed at a fixed position and a rotating part, respectively controlling the magnet to rotate around two mutually perpendicular rotation axes. When the rotating part rotates, one of the motors rotates together with the rotating part, so the rotation radius is relatively large; at the same time, in order to prevent the motor cable and the zero return photoelectric sensor cable from being entangled and pulled apart during rotation, an electric slip ring is required for rotating conduction and signal transmission. The electric slip ring has a complex structure, high cost, high process requirements, and a short life. It is easily interfered when transmitting sensitive signals, resulting in poor reliability of the magnetron device.

[0006] In view of the above-mentioned defects of the prior art, it is necessary to develop an articulated arm and a control method thereof which is easy to operate, simple in appearance, small in size and highly reliable. Summary of the invention

[0007] In the first aspect, the present invention provides an articulated arm, comprising a first driving part, a second driving part, a rotating part and a driving plate, wherein the first driving part is a hollow structure, a first motor is arranged inside the first driving part, the first motor further comprises a stator and a rotor, the rotor of the first motor can rotate around a first axis, the rotating part is fixedly connected to a first flange end face of the first driving part, and can rotate around the first axis with the first flange, the second driving part is arranged above the first driving part, the output shaft of the second driving part passes through the hollow structure of the first driving part and is connected to the first bevel gear in the rotating part, and can drive the permanent magnet assembly in the rotating part to rotate around a second axis perpendicular to the first axis.

[0008] Furthermore, the driving plate of the articulated arm is fixedly disposed above the second driving part, and is used to drive the first motor of the first driving part and the second motor of the second driving part.

[0009] Furthermore, the first motor stator is fixedly disposed between the first motor seat and the first sleeve, and the first motor rotor is fixed to the outside of the first rotating shaft.

[0010] Furthermore, the first driving part further includes a first rotating shaft, a first motor seat and a first bearing, and the first rotating shaft is rotatably connected to the inner side of the first motor seat through the first bearing.

[0011] Furthermore, the outer ring of the first bearing is fixedly connected between the first cover plate and the first motor seat, and the inner ring of the first bearing is fixedly connected between the first rotating shaft and the first flange.

[0012] Furthermore, the first driving part further includes a first auxiliary shaft, the first auxiliary shaft is fixedly connected to the upper end surface of the first rotating shaft, and the rotor of the first motor drives the first auxiliary shaft, the first rotating shaft and the first flange to rotate around the first axis.

[0013] Furthermore, the second driving part also includes a harmonic reducer, and the harmonic reducer further includes a harmonic reducer fixed end, a harmonic reducer input end and a harmonic reducer output end. The harmonic reducer fixed end is fixedly connected between the second flange and the second motor seat, the second flange is fixedly connected above the first sleeve of the first driving part, the harmonic reducer input end is fixedly connected between the second rotating shaft and the fastening nut, the harmonic reducer output end is fixedly connected to the output shaft, and the harmonic reducer input end and the harmonic reducer output end can rotate around the first axis.

[0014] Furthermore, the second motor includes a stator and a rotor, the stator of the second motor is fixedly disposed between the second motor base and the second sleeve, and the rotor of the second motor is fixed to the outside of the second rotating shaft.

[0015] Furthermore, the second driving part further includes a second bearing, and the second rotating shaft is rotatably connected to the inner side of the second motor base through the second bearing.

[0016] Furthermore, the outer ring of the second bearing is fixedly connected between the second motor base and the second cover plate, and the inner ring of the second bearing is fixedly connected between the second rotating shaft and the inner ring pressure plate.

[0017] Furthermore, the rotating part also includes an upper bracket, a left bracket and a right bracket fixedly arranged on both sides of the upper bracket, and a permanent magnet assembly. The permanent magnet assembly is rotatably connected between the left bracket and the right bracket, and can rotate around a second axis perpendicular to the first axis.

[0018] Furthermore, the rotating part also includes an output shaft, a first bevel gear, a second bevel gear, a reversing shaft, a first synchronous wheel, a synchronous belt, a tensioning wheel and a second synchronous wheel. The output shaft drives the reversing shaft to rotate through a gear pair composed of the first bevel gear and the second bevel gear. The reversing shaft further drives the permanent magnet assembly to rotate around the second axis through a synchronous belt transmission mechanism composed of the first synchronous wheel, the synchronous belt, the tensioning wheel and the second synchronous wheel.

[0019] Furthermore, the synchronous belt transmission mechanism is arranged on the outside of the left bracket, the first synchronous wheel is connected to the reversing shaft and rotates therewith, and the second synchronous wheel is connected to the end of the rotating shaft connecting the permanent magnet assembly and the left bracket, and drives the permanent magnet assembly to rotate.

[0020] Furthermore, the two ends of the reversing shaft are rotatably connected to the left bracket and the right bracket respectively, the synchronous belt transmission mechanism is arranged on the inner side of the right bracket, and the second synchronous wheel is connected to the permanent magnet assembly housing and drives the permanent magnet assembly to rotate around the second axis.

[0021] The second invention provides a control method for an articulated arm, wherein the articulated arm adopts the articulated arm according to any one of claims 1 to 14, and the speed of the first motor is n 1 , the second motor speed is n 2 , the reduction ratio of the harmonic reducer is i, the transmission ratio of the synchronous belt transmission mechanism is j, and the transmission ratio of the first bevel gear and the second bevel gear is k, then:

[0022] The rotation speed m of the rotating part around the first axis 1 for: ;

[0023] The rotation speed of the rotating part around the second axis m 2 for: .

[0024] The articulated arm disclosed in the present invention is different from the solution of directly installing the motor on the rotating part in the traditional magnetic control device. Instead, the motor is installed in a superimposed manner at the top fixed position, which minimizes the turning radius of the turning part. At the same time, due to the positioning solution of the absolute encoder, the photoelectric zero return mechanism in the traditional solution is eliminated, the cable winding problem of the turning part is avoided, and the expensive electric slip ring device is eliminated. Therefore, compared with the traditional solution, the articulated arm disclosed in the present invention has a simple appearance, a smaller volume and a smaller turning radius, and high reliability. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] Figure 1 : Schematic diagram of the overall structure of the articulated arm in the first embodiment of the present invention.

[0026] Figure 2 : Figure 1 Schematic diagram of the exploded structure of the articulated arm shown.

[0027] Figure 3 : Figure 1 A schematic diagram of the partial cross-sectional structure of the first driving part in the articulated arm is shown.

[0028] Figure 4 : Figure 3 A schematic diagram of the partial exploded structure of the first driving unit is shown.

[0029] Figure 5 : Figure 1 A schematic diagram of the partial cross-sectional structure of the second driving part in the articulated arm is shown.

[0030] Figure 6 : Figure 5 A schematic diagram of the partial exploded structure of the second driving unit is shown.

[0031] Figure 7 : Figure 1 Schematic diagram of the structure of the rotating part in the articulated arm shown.

[0032] Figure 8 : A schematic structural diagram of the rotary portion in the second embodiment of the present invention.

[0033] The serial numbers and corresponding names are: first driving part 10, second driving part 20, rotating part 30, driving plate 40, first axis 1, first encoder 101, first auxiliary shaft 102, first sleeve 103, first motor 104, first rotating shaft 105, first motor seat 106, first bearing 107, first flange 108, first cover plate 109, second encoder 201, second sleeve 202, second auxiliary shaft 203, second motor 204, second cover plate 2 05, second rotating shaft 206, second bearing 207, second motor seat 208, inner ring pressure plate 209, harmonic reducer 210, fastening nut 211, second flange 212, output shaft 213, second axis 2, upper bracket 301, left bracket 302, right bracket 303, first bevel gear 304, second bevel gear 305, reversing shaft 306, first synchronous wheel 307, synchronous belt 308, tensioning wheel 309, second synchronous wheel 310, permanent magnet assembly 311. DETAILED DESCRIPTION

[0034] See also Figure 1 The overall structure diagram of the articulated arm in the first embodiment of the present invention and Figure 2 Schematic diagram of the exploded structure of the articulated arm. The present invention provides an articulated arm, which includes a first driving part 10, a second driving part 20, a rotating part 30 and a driving plate 40, wherein the first driving part 10 is a hollow structure, and a first motor 104 is arranged inside, the rotor of the first motor 104 can rotate around a first axis 1, the rotating part 30 is fixedly connected to the end face of the first flange 108 of the first driving part 10, and can rotate around the first axis 1 with the first flange 108, the second driving part 20 is arranged above the first driving part 10, the output shaft 213 of the second driving part 20 passes through the hollow structure of the first driving part 10 to connect to the first bevel gear 304 in the rotating part 30, and can drive the permanent magnet assembly 311 in the rotating part 30 to rotate around a second axis 2 perpendicular to the first axis 1.

[0035] Furthermore, the driving plate 40 of the articulated arm is fixedly disposed above the second driving part 20 , and is used to drive the first motor 104 and the second motor 204 in the first driving part 10 and the second driving part 20 .

[0036] refer to Figure 3 yes Figure 1 A partial cross-sectional structural diagram of the first driving part in the articulated arm shown in FIG. Figure 4 yes Figure 3The schematic diagram of the partial decomposition structure of the first driving part shown in the figure, the first driving part 10 includes a first motor 104, and the first motor 104 further includes a stator and a rotor (not shown in the figure), the stator of the first motor 104 is fixedly arranged between the first motor seat 106 and the first sleeve 103, and the rotor of the first motor 104 is fixed to the outside of the first rotating shaft 105, and the first rotating shaft 105 is rotatably connected to the inside of the first motor seat 106 through the first bearing 107.

[0037] Preferably, the outer ring of the first bearing 107 is fixedly connected between the first cover plate 109 and the first motor seat 106 , and the inner ring of the first bearing 107 is fixedly connected between the first rotating shaft 105 and the first flange 108 .

[0038] Preferably, the first auxiliary shaft 102 is fixedly connected to the upper end surface of the first rotating shaft 105, and the rotor of the first motor 104 drives the first auxiliary shaft 102, the first rotating shaft 105 and the first flange 108 to rotate around the first axis 1;

[0039] Preferably, the first encoder 101 further includes a sensor plate and a code disc, the sensor plate of the first encoder 101 is fixedly connected to the upper end of the first sleeve 103, the code disc of the first encoder 101 is fixedly connected to the upper end of the first auxiliary shaft 102, and rotates around the first axis 1 with the first auxiliary shaft 102.

[0040] Figure 5 yes Figure 1 A partial cross-sectional structural diagram of the second driving part in the articulated arm shown in FIG. Figure 6 yes Figure 5 The schematic diagram of the partial decomposition structure of the second driving part shown in the figure, the second driving part 20 includes a harmonic reducer 210, and the harmonic reducer 210 further includes a harmonic reducer fixed end, a harmonic reducer input end and a harmonic reducer output end (not shown in the figure), the harmonic reducer fixed end is fixedly connected between the second flange 212 and the second motor base 208, the second flange 212 is fixedly connected to the top of the first sleeve 103 of the first driving part 10, the harmonic reducer input end is fixedly connected between the second rotating shaft 206 and the fastening nut 211, the harmonic reducer output end is fixedly connected to the output shaft 213, and the harmonic reducer input end and the harmonic reducer output end can rotate around the first axis 1.

[0041] Preferably, the second driving unit 20 also includes a second motor 204, which includes a stator and a rotor (not shown in the figure). The stator of the second motor 204 is fixedly arranged between the second motor seat 208 and the second sleeve 202, and the rotor of the second motor 204 is fixed to the outside of the second rotating shaft 206. At the same time, the second rotating shaft 206 is rotatably connected to the inside of the second motor seat 208 through a second bearing 207.

[0042] Preferably, the outer ring of the second bearing 207 is fixedly connected between the second motor base 208 and the second cover plate 205 , and the inner ring of the second bearing 207 is fixedly connected between the second rotating shaft 206 and the inner ring pressure plate 209 .

[0043] Preferably, the second auxiliary shaft 203 is fixedly connected above the second rotating shaft 206, and the rotor of the second motor 204 drives the second auxiliary shaft 203, the second rotating shaft 206 and the input end of the harmonic reducer 210 to rotate around the first rotating axis, and after deceleration, the output end of the harmonic reducer 210 drives the output shaft 213 to rotate around the first axis 1.

[0044] Preferably, the second encoder 201 includes a sensor plate and a code disc (not shown in the figure), the sensor plate of the second encoder 201 is fixedly connected to the upper end of the second sleeve 202, the code disc of the second encoder 201 is fixedly connected to the upper end of the second auxiliary shaft 203, and rotates around the first axis 1 with the second auxiliary shaft 203.

[0045] Figure 7 yes Figure 1 The structural schematic diagram of the rotating part in the joint arm shown in the figure, the rotating part 30 includes an upper bracket 301 and a left bracket 302 and a right bracket 303 fixedly arranged on both sides of the upper bracket 301, the permanent magnet assembly 311 is rotatably connected between the left bracket 302 and the right bracket 303, and can rotate around a second axis 2 perpendicular to the first axis 1, the output shaft 213 drives the reversing shaft 306 to rotate through a gear pair composed of a first bevel gear 304 and a second bevel gear 305, and the reversing shaft 306 further drives the permanent magnet assembly 311 to rotate around the second axis 2 through a synchronous belt transmission mechanism composed of a first synchronous wheel 307, a synchronous belt 308, a tensioning wheel 309 and a second synchronous wheel 310.

[0046] Preferably, the synchronous belt transmission mechanism is arranged on the outside of the left bracket 302, wherein the first synchronous wheel 307 is connected to the reversing shaft 306 and rotates therewith, and the second synchronous wheel 310 is connected to the end of the rotating shaft connecting the permanent magnet assembly 311 and the left bracket 302, and drives the permanent magnet assembly 311 to rotate.

[0047] refer to Figure 8 A schematic structural diagram of the rotating part in the second embodiment of the present invention. In the second embodiment, both ends of the reversing shaft 306 are rotatably connected to the left bracket 302 and the right bracket 303 respectively, and the synchronous belt transmission mechanism is arranged on the inner side of the right bracket 303. The second synchronous wheel 310 is connected to the outer shell of the permanent magnet assembly 311 and drives the permanent magnet assembly 311 to rotate around the second axis 2.

[0048] The present invention also provides a control method for the articulated arm: due to the particularity of the articulated arm transmission mechanism, when the first motor 104 rotates and the second motor 204 is stationary, the rotating part 30 will rotate synchronously with the rotor of the first motor 104, and at the same time, the second bevel gear 305 will rotate synchronously when revolving around the first bevel gear 304, thereby driving the permanent magnet assembly 311 to rotate around the second axis 2. Therefore, the first motor 104 and the second motor 204 do not independently control the rotation of the first axis 1 and the second axis 2 respectively.

[0049] When the permanent magnet assembly 311 is required to rotate independently around the second axis 2, the second motor 204 is controlled to rotate and the first motor 104 remains stopped; when the permanent magnet assembly 311 is required to rotate independently around the first axis 1, when controlling the second motor 204 to rotate, the first motor 104 must be controlled to rotate at the same time, and when the second bevel gear 305 revolves around the first bevel gear 304, the first bevel gear 304 and the second bevel gear 305 remain relatively stationary without meshing transmission, that is, the second bevel gear 305 does not rotate on its own.

[0050] Furthermore, the relationship between the rotation speed of the rotating part 30 around the first axis 1 and the second axis 2 and the motor speed is as follows:

[0051] Assume that the speed of the first motor 104 is n 1 , the speed of the second motor 204 is n 2 , the reduction ratio of the harmonic reducer 210 is i, the transmission ratio of the synchronous belt transmission mechanism is j, and the transmission ratio of the first bevel gear 304 and the second bevel gear 305 is k, then:

[0052] The rotation speed m of the rotating part 30 around the first axis 1 1 for:

[0053] The rotation speed m of the rotating part 30 around the second axis 2 2 for: .

[0054] Although the spirit and essence of the present invention have been described in the best embodiment, those skilled in the art may improve the present invention without departing from the spirit and essence of the present invention, and these improvements still fall within the protection scope of the present invention.

[0055] The articulated arm disclosed in the present invention adopts a motor that is superimposed and installed at a top fixed position, which reduces the turning radius to the maximum extent and eliminates the electric slip ring device. Therefore, the articulated arm has a simple appearance, a small volume and a turning radius, and high reliability.

Claims

1. An articulated arm, characterized in that: The invention comprises a first driving part, a second driving part, a rotating part and a driving plate, wherein the first driving part is a hollow structure, a first motor and a first flange are arranged inside the first driving part, the first motor further comprises a stator and a rotor, the rotor of the first motor can drive the first flange to rotate around a first axis, the rotating part is fixedly connected to the first flange end face of the first driving part, and can rotate around the first axis with the first flange, the second driving part is arranged above the first driving part, the output shaft of the second driving part passes through the hollow structure of the first driving part and is connected to the first bevel gear in the rotating part, and can drive the permanent magnet assembly in the rotating part to rotate around a second axis perpendicular to the first axis.

2. The articulated arm according to claim 1, characterized in that: The driving plate of the articulated arm is fixedly disposed above the second driving part, and is used to drive the first motor of the first driving part and the second motor of the second driving part.

3. The articulated arm according to claim 1, characterized in that: The first motor stator is fixedly arranged between the first motor seat and the first sleeve, and the first motor rotor is fixed on the outside of the first rotating shaft.

4. The articulated arm according to claim 1, characterized in that: The first driving part further includes a first rotating shaft, a first motor seat and a first bearing, and the first rotating shaft is rotatably connected to the inner side of the first motor seat through the first bearing.

5. The articulated arm according to claim 4, characterized in that: The outer ring of the first bearing is fixedly connected between the first cover plate and the first motor seat, and the inner ring of the first bearing is fixedly connected between the first rotating shaft and the first flange.

6. The articulated arm according to claim 4, characterized in that: The first driving part further includes a first auxiliary shaft, which is fixedly connected to the upper end surface of the first rotating shaft. The rotor of the first motor drives the first auxiliary shaft, the first rotating shaft and the first flange to rotate around the first axis.

7. The articulated arm according to claim 2, characterized in that: The second driving part also includes a harmonic reducer, and the harmonic reducer further includes a harmonic reducer fixed end, a harmonic reducer input end and a harmonic reducer output end. The harmonic reducer fixed end is fixedly connected between the second flange and the second motor seat, the second flange is fixedly connected above the first sleeve of the first driving part, the harmonic reducer input end is fixedly connected between the second rotating shaft and the fastening nut, the harmonic reducer output end is fixedly connected to the output shaft, and the harmonic reducer input end and the harmonic reducer output end can rotate around the first axis.

8. The articulated arm according to claim 7, characterized in that: The second motor includes a stator and a rotor. The second motor stator is fixedly disposed between the second motor seat and the second sleeve, and the second motor rotor is fixed to the outside of the second rotating shaft.

9. The articulated arm according to claim 8, characterized in that: The second driving part further includes a second bearing, and the second rotating shaft is rotatably connected to the inner side of the second motor base through the second bearing.

10. The articulated arm according to claim 9, characterized in that: The outer ring of the second bearing is fixedly connected between the second motor base and the second cover plate, and the inner ring of the second bearing is fixedly connected between the second rotating shaft and the inner ring pressure plate.

11. The articulated arm according to claim 7, characterized in that: The rotating part also includes an upper bracket, a left bracket and a right bracket fixedly arranged on both sides of the upper bracket, and a permanent magnet assembly. The permanent magnet assembly is rotatably connected between the left bracket and the right bracket and can rotate around a second axis perpendicular to the first axis.

12. The articulated arm according to claim 11, characterized in that: The rotating part also includes a second bevel gear, a reversing shaft, a first synchronous wheel, a synchronous belt, a tension wheel and a second synchronous wheel. The output shaft drives the reversing shaft to rotate through a gear pair consisting of the first bevel gear and the second bevel gear. The gear pair is arranged between the left bracket and the right bracket. The reversing shaft further drives the permanent magnet assembly to rotate around the second axis through a synchronous belt transmission mechanism consisting of the first synchronous wheel, the synchronous belt, the tension wheel and the second synchronous wheel. The synchronous belt transmission mechanism is arranged on the outside of the left bracket.

13. The articulated arm according to claim 12, characterized in that: The synchronous belt transmission mechanism is arranged outside the left bracket, the first synchronous wheel is connected to the reversing shaft and rotates therewith, and the second synchronous wheel is connected to the end of the rotating shaft connecting the permanent magnet assembly and the left bracket, and drives the permanent magnet assembly to rotate.

14. The articulated arm according to claim 12, characterized in that: The two ends of the reversing shaft are rotatably connected to the left bracket and the right bracket respectively, the synchronous belt transmission mechanism is arranged on the inner side of the right bracket, and the second synchronous wheel is connected to the permanent magnet assembly housing and drives the permanent magnet assembly to rotate around the second axis.

15. A method for controlling an articulated arm, characterized in that: The articulated arm adopts the articulated arm according to any one of claims 12 to 14, the speed of the first motor is n1, the speed of the second motor is n2, the reduction ratio of the harmonic reducer is i, the transmission ratio of the synchronous belt transmission mechanism is j, and the transmission ratio of the first bevel gear and the second bevel gear is k, then: The rotation speed m1 of the rotating part around the first axis is: ； The rotation speed m2 of the rotating part around the second axis is: 。

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