A high-precision, lightweight and compact three-axis stabilized platform

Abstract

A high-precision, light and small three-axis stabilized platform belongs to the field of aerial photography technology, and includes a bias flow assembly, a pitch assembly and a roll assembly. The bias flow assembly and the pitch assembly are connected by a bearing structure, and the pitch assembly and the roll assembly are connected by a bearing structure. The overall structure is compact, small in size, light in weight, easy to install, strong in load-bearing capacity, and high in stability and precision. It can meet the operating requirements of various aerial remote sensors, especially for small unmanned aerial vehicles, and its application performance is excellent.

Description

Technical Field

[0001] The invention belongs to the technical field of aerial photography and relates to a high-precision, light and small three-axis stable platform. Background Art

[0002] With the vigorous development of my country's economy, issues such as land survey, resource protection, sudden disaster control, and environmental protection are becoming more and more important, and there are more and more corresponding activities. Aerial remote sensors mostly use small drones, which are characterized by small size, light weight, and can only carry small loads. The photography system carried by small drones has no self-stabilization function and is greatly affected by the aircraft attitude and working environment. Most small drones fly in airspace below 6,000 meters. The airflow in this airspace is relatively unstable, which can cause the aircraft to vibrate violently. The angle between the aircraft and the ground is constantly changing. Strong winds will also cause the aircraft attitude to change continuously. The change in the aircraft attitude will cause the angle between the photography system and the ground to change continuously. When the angle changes greatly, the overlap rate between the acquired images is too low, resulting in discontinuity of the overall image. The image cannot be fully spliced ​​during post-processing, which greatly reduces the effectiveness of acquiring images and even causes the failure of the flight mission. In order to ensure the stability of the photography system of the small drone, a light and small three-axis stable platform with high stability and accuracy must be designed to ensure that the photography system always remains perpendicular to the ground during the mission operation, ensuring the imaging stability of the photography system, which can greatly improve the effectiveness and accuracy of acquiring image information.

[0003] The common three-axis stabilized platform is large in size, heavy in weight, and weak in carrying capacity, which cannot meet the requirements of most existing small UAVs for mission payloads: the three-axis stabilized platform is large in size, while the small UAV is small in size, so it cannot be installed; the three-axis stabilized platform is heavy in weight, while the small UAV is small in weight and has weak carrying capacity, which limits the use of the camera system and can only carry a lighter camera system, and cannot use multiple mission payloads at the same time, resulting in a single function of the entire aviation system, increasing time and money costs. According to the characteristics of small UAVs, a high-precision, light and small three-axis stabilized platform with small size, light weight and strong carrying capacity was invented, which has a relatively simple and compact structure and high reliability to meet the use requirements of most existing small UAVs. Summary of the invention

[0004] The purpose of the present invention is to solve the problem that the traditional three-axis stabilized platform is large in size, heavy in mass, and has weak carrying capacity, and is difficult to adapt to the current requirements of small UAVs for miniaturization and lightweight of mission payloads. A three-axis stabilized platform with compact structure, small size, light mass and strong carrying capacity is invented.

[0005] A three-axis stable platform comprises a deflection component, a pitch component and a roll component.

[0006] The deflector assembly is installed on the pitch assembly, and the two are connected by using the pitch axis and the bearing inner ring pressure cover at both ends to press the inner ring of the ball bearing. The pitch assembly is installed on the roll assembly, and the two are connected by using the bearing inner ring pressure cover and the roll axis at both ends to press the inner ring of the ball bearing.

[0007] The bias flow assembly includes a bias flow inner frame, a bias flow outer frame upper frame, a bias flow outer frame lower frame, a bias flow bearing assembly, a first reducer drive assembly, a ball bearing, a three-axis fiber optic gyroscope, a first zero position proximity switch sensing element, a first zero position proximity switch, a bearing outer ring pressure cover, a bias flow mechanical limit column, a synchronous transmission belt, a bias flow driven gear, a pitch mechanical limit column, a pitch driven gear and a first reducer drive assembly protective cover;

[0008] The upper frame of the bias flow outer frame, the lower frame of the bias flow outer frame and the bias flow inner frame are made of aviation super-hard aluminum material and stabilized to ensure that the assembly is firm and has sufficient strength and rigidity; the ball bearing is installed in the lower frame of the bias flow outer frame, and the outer ring of the ball bearing is pressed by the bearing outer ring pressure cover. The bias flow bearing assembly is respectively installed between the bias flow inner frame and the upper frame of the bias flow outer frame and between the bias flow inner frame and the lower frame of the bias flow outer frame. The first reducer drive assembly is installed on the lower frame of the bias flow outer frame, and the bias flow driven gear is driven by the synchronous transmission belt. The bias flow mechanical limit column is installed In the lower frame of the bias flow outer frame, the pitch mechanical limit column is installed in the lower frame of the bias flow outer frame, and the three-axis fiber optic gyroscope is installed in the lower frame of the bias flow outer frame to simultaneously sense the attitude, angular velocity and angular acceleration of the three axis systems in the inertial space. The first zero position proximity switch is installed in the lower frame of the bias flow outer frame. By sensing the real-time position of the sensed component of the first zero position proximity switch during the rotation process, the control of the platform bias flow movement is achieved. The first reducer drive assembly protective cover is installed on the first reducer drive assembly, and the pitch driven gear is installed on the lower frame of the bias flow outer frame.

[0009] The deflection flow bearing assembly includes precision steel balls, a bearing outer ring steel sleeve, a bearing inner ring steel sleeve and a bearing retainer; the bearing outer ring steel sleeve is respectively installed in the lower end surface of the inner ring of the upper frame of the deflection flow outer frame and the upper end surface of the inner ring of the lower frame of the deflection flow outer frame, the bearing inner ring steel sleeve is respectively installed in the upper end surface and the lower end surface of the outer ring of the deflection flow inner frame, the two bearing retainers are respectively installed in two groups of bearing outer ring steel sleeves and bearing inner ring steel sleeves, and the precision steel balls are installed in the bearing retainers.

[0010] The bearing outer ring steel sleeve and the bearing inner ring steel sleeve are made of aviation steel.

[0011] The first reducer drive assembly, the second reducer drive assembly and the third reducer drive assembly include a driving gear, a reducer and a torque motor; the reducer is installed on the torque motor, the driving driving gear is installed on the reducer, and the torque motor drives the driving gear through the deceleration effect of the reducer.

[0012] The pitch assembly includes a second reducer drive assembly, a second zero-position proximity switch, a third reducer drive assembly, a third zero-position proximity switch, a pitch axis, a pitch frame, a bearing inner ring pressure cover, a roll axis and an upper shell; the second reducer drive assembly, the second zero-position proximity switch, the third reducer drive assembly, the third zero-position proximity switch, the pitch axis, the roll axis and the upper shell are respectively mounted on the pitch frame, the bearing inner ring pressure cover is respectively mounted on the pitch axis and the roll axis, the ball bearing inner ring is compressed, the second zero-position proximity switch is used to sense the real-time position of the pitch driven gear during the rotation process, so as to realize the control of the platform pitch motion, and the third zero-position proximity switch is used to sense the real-time position of the roll driven gear during the rotation process, so as to realize the control of the platform roll motion.

[0013] The roll assembly includes a handle, a roll bearing support, a roll driven gear, a roll driven gear support, a roll frame, a roll mechanical limit column and a shock absorber; the handle is installed on both sides of the roll frame, which is conducive to moving the platform without damaging the structure, the roll bearing support, the roll driven gear support, the roll mechanical limit column and the shock absorber are respectively installed on the roll frame, the shock absorber can effectively isolate high-frequency vibrations, the ball bearing is installed in the roll bearing support, the outer ring of the ball bearing is pressed by the bearing outer ring pressure cover, and the roll driven gear is installed on the roll driven gear support.

[0014] Beneficial results of the present invention:

[0015] 1. The bias flow bearing mechanism of the present invention adopts a special structural form. The outer ring steel sleeve of the bearing is embedded in the upper frame and the lower frame of the bias flow outer frame through a special processing method, so that there is no gap and relative movement between them. The inner ring steel sleeve of the bearing is embedded in the bias flow inner frame through the same processing method, so that there is no gap and relative movement between them. High-precision steel balls and bearing retainers are installed therein to form a bearing mechanism. The upper frame of the bias flow outer frame, the lower frame of the bias flow outer frame and the bias flow inner frame are both the main supporting structures of the three-axis stable platform and the main supporting structures of the bearings, which can greatly reduce the mass and volume of the platform; by adjusting the number of steel balls, the bearing's load-bearing capacity can be arbitrarily adjusted; ensuring that the platform has the characteristics of compact structure, light mass, small volume and strong load-bearing capacity.

[0016] 2. The bias flow shaft transmission method of the present invention adopts a reducer drive assembly to drive a synchronous transmission belt, and the synchronous transmission belt drives the bias flow driven gear. The bias flow driven gear is fastened to the bias flow inner frame, thereby realizing a transmission method for driving the bias flow shaft to rotate. The angle range of the bias flow shaft rotation can be adjusted arbitrarily by adjusting the length of the synchronous transmission belt, which shortens the distance between the reducer drive assembly and the bias flow shaft frame to the greatest extent, reduces the overall size and overall mass of the three-axis stable platform, has a simple structure, and is easy to install. It can be connected by only 4 screws.

[0017] 3. The sensor of the present invention adopts a three-axis fiber optic gyroscope and a first zero-position proximity switch, a second zero-position proximity switch, and a third zero-position proximity switch. The three-axis fiber optic gyroscope simultaneously detects the posture, angular velocity, and angular acceleration of the three axis systems in the inertial space. The first zero-position proximity switch, the second zero-position proximity switch, and the third zero-position proximity switch measure the rotation angle, which can meet the stability accuracy requirements of the three-axis stable platform. It has a small size, is easy to install, requires a small number of sensors, and is low in price. It effectively reduces the cost while ensuring the performance of the three-axis stable platform.

[0018] 4. The drive chain of the present invention undergoes two-stage deceleration effect: the torque motor drive assembly in the eccentric bearing assembly has an internal reducer to complete the first stage of deceleration effect; the active gear drives the driven gear to complete the second stage of deceleration effect; the product of the two-stage reduction ratios is used as the final reduction ratio. Under the same reduction ratio, the platform system has a lighter mass, a smaller volume, a stronger load-bearing capacity, and is more in line with the stability control requirements of the three-axis stable platform.

[0019] 5. The drive motor of the present invention adopts a torque motor, and the drive motor, reducer and driving gear are used as an integral component, which has the advantages of high integration, simple structure, high transmission accuracy, large torque, small size and light weight. The three-axis stable platform has a mass of only 3kg, which is 2.2kg lighter than the world's advanced small platform CSM132. The overall dimensions are 357mm long, 247mm wide and 110.5mm high. Compared with similar products of the same quality or volume, it has a stronger load-carrying capacity, and the load mass can reach 0-10kg. At the same time, the stability accuracy is higher, and the installation is more convenient and quick. One end of the reducer drive assembly is directly installed on the pitch frame and connected by 4 screws.

[0020] 6. The load installation diameter of the present invention is The center of the pitch axis and the center of the roll axis are on the same horizontal plane and are orthogonal to each other, so that the center of mass of the three-axis stabilized platform is located at the intersection of the three axis centers, thereby eliminating the influence of the mass eccentricity of the three-axis stabilized platform itself and optimizing the control accuracy of the three-axis stabilized platform. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] Figure 1 It is a schematic diagram of the overall structure of the present invention.

[0022] Figure 2 Schematic diagram of the bias flow assembly of the present invention Figure 1 .

[0023] Figure 3 Schematic diagram of the bias flow assembly of the present invention Figure 2 .

[0024] Figure 4It is a schematic diagram of the bias flow bearing assembly of the present invention.

[0025] Figure 5 It is a schematic diagram of the reducer drive assembly of the present invention.

[0026] Figure 6 It is a schematic diagram of the pitch assembly of the present invention.

[0027] Figure 7 It is a schematic diagram of the rolling assembly of the present invention.

[0028] Among them, 1-bias flow assembly, 2-pitch assembly, 3-roll assembly, 4-bias flow inner frame, 5-bias flow outer frame upper frame, 6-bias flow outer frame lower frame, 7-bias flow bearing assembly, 8-first reducer drive assembly, 9-ball bearing, 10-three-axis fiber optic gyroscope, 11-first zero position proximity switch sensing element, 12-first zero position proximity switch, 13-bearing outer ring pressure cover, 14-bias flow mechanical limit column, 15-synchronous transmission belt, 16-bias flow driven gear, 17-pitch mechanical limit column, 18-pitch driven gear, 19-first reducer drive assembly protective cover, 20-precision steel ball, 2 1-bearing outer ring steel sleeve, 22-bearing inner ring steel sleeve, 23-bearing retainer, 24-driving gear, 25-reducer, 26-torque motor, 27-pitch axis, 28-second reducer drive assembly, 29-second zero position proximity switch, 30-pitch frame, 31-bearing inner ring pressure cover, 32-roll axis, 33-third zero position proximity switch, 34-third reducer drive assembly, 35-upper shell, 36-handle, 37-roll bearing support, 38-roll driven gear, 39-roll driven gear support, 40-roll frame, 41-roll mechanical limit column, 42-shock absorber. DETAILED DESCRIPTION

[0029] like Figure 1 As shown, a three-axis stable platform includes a bias flow component 1, a pitch component 2 and a roll component 3.

[0030] The deflector assembly 1 is installed on the pitch assembly 2, and the two are connected by using the pitch axis 27 and the bearing inner ring pressure cover 31 at both ends to press the inner ring of the ball bearing 9. The pitch assembly 2 is installed on the roll assembly 3, and the two are connected by using the bearing inner ring pressure cover 31 and the roll axis 32 at both ends to press the inner ring of the ball bearing 9.

[0031] like Figure 2 and Figure 3As shown, the bias flow assembly 1 includes a bias flow inner frame 4, a bias flow outer frame upper frame 5, a bias flow outer frame lower frame 6, a bias flow bearing assembly 7, a first reducer drive assembly 8, a ball bearing 9, a three-axis fiber optic gyroscope 10, a first zero position proximity switch sensing element 11, a first zero position proximity switch 12, a bearing outer ring pressure cover 13, a bias flow mechanical limit column 14, a synchronous transmission belt 15, a bias flow driven gear 16, a pitch mechanical limit column 17, a pitch driven gear 18 and a first reducer drive assembly protective cover 19;

[0032] The upper frame 5 of the bias flow outer frame, the lower frame 6 of the bias flow outer frame and the bias flow inner frame 4 are made of aviation super-hard aluminum material and stabilized to ensure that the assembly is firm and has sufficient strength and rigidity;

[0033] The ball bearing 9 is installed in the lower frame 6 of the bias flow outer frame, and the outer ring of the ball bearing 9 is pressed by the bearing outer ring pressure cover 13. The bias flow bearing assembly 7 is respectively installed between the bias flow inner frame 4 and the bias flow outer frame upper frame 5 and between the bias flow inner frame 4 and the bias flow outer frame lower frame 6. The first reducer drive assembly 8 is installed on the bias flow outer frame lower frame 6, and the bias flow driven gear 16 is driven by the synchronous transmission belt 15. The bias flow mechanical limit column 14 is installed in the bias flow outer frame lower frame 6, and the pitch mechanical limit column 17 is installed under the bias flow outer frame In frame 6, a three-axis fiber optic gyroscope 10 is installed in the lower frame 6 of the bias flow outer frame, and simultaneously senses the attitude, angular velocity and angular acceleration of the three axis systems in the inertial space. A first zero position proximity switch 12 is installed in the lower frame 6 of the bias flow outer frame. By sensing the real-time position of the sensed component 11 of the first zero position proximity switch during the rotation process, the control of the platform bias flow movement is realized. The first reducer drive assembly protective cover 19 is installed on the first reducer drive assembly 8, and the pitch driven gear 18 is installed on the lower frame 6 of the bias flow outer frame.

[0034] like Figure 4 As shown, the bias flow bearing assembly 7 includes precision steel balls 20, a bearing outer ring steel sleeve 21, a bearing inner ring steel sleeve 22 and a bearing retainer 23; the bearing outer ring steel sleeve 21 is respectively installed in the lower end surface of the inner ring of the bias flow outer frame upper frame 5 and the upper end surface of the inner ring of the bias flow outer frame lower frame 6, the bearing inner ring steel sleeve 22 is respectively installed in the upper end surface and lower end surface of the outer ring of the bias flow inner frame 4, the two bearing retainers 23 are respectively installed in two groups of bearing outer ring steel sleeves 21 and bearing inner ring steel sleeves 22, and the precision steel balls 20 are installed in the bearing retainers 23.

[0035] The bearing outer ring steel sleeve 21 and the bearing inner ring steel sleeve 22 are made of aviation steel material.

[0036] like Figure 5As shown, the first reducer drive assembly 8, the second reducer drive assembly 28 and the third reducer drive assembly 34 include a driving gear 24, a reducer 25 and a torque motor 26; the reducer 25 is installed on the torque motor 26, and the driving gear 24 is installed on the reducer 25, and the torque motor 26 drives the driving gear 24 through the deceleration effect of the reducer 25.

[0037] like Figure 6 As shown, the pitch assembly 2 includes a pitch axis 27, a second reducer drive assembly 28, a second zero position proximity switch 29, a pitch frame 30, a bearing inner ring pressure cover 31, a roll axis 32, a third zero position proximity switch 33, a third reducer drive assembly 34 and an upper shell 35; the pitch axis 27, the second reducer drive assembly 28, the second zero position proximity switch 29, the roll axis 32, the third zero position proximity switch 33, the third reducer drive assembly 34 and the upper shell 35 are respectively mounted on the pitch frame 30, the bearing inner ring pressure cover 31 is respectively mounted on the pitch axis 27 and the roll axis 32, and the inner ring of the ball bearing 9 is pressed tightly, and the real-time position of the pitch driven gear 18 during the rotation process is sensed by the second zero position proximity switch 29 to realize the control of the pitch motion of the platform, and the real-time position of the roll driven gear 38 during the rotation process is sensed by the third zero position proximity switch 33 to realize the control of the roll motion of the platform.

[0038] like Figure 7 As shown, the roll assembly 3 includes a handle 36, a roll bearing support 37, a roll driven gear 38, a roll driven gear support 39, a roll frame 40, a roll mechanical limit column 41 and a shock absorber 42; the handle 36 is installed on both sides of the roll frame 40, which is conducive to moving the platform without damaging the structure, the roll bearing support 37, the roll driven gear support 39, the roll mechanical limit column 41, and the shock absorber 42 are respectively installed on the roll frame 40, and the shock absorber 42 can effectively isolate high-frequency vibrations, the ball bearing 9 is installed in the roll bearing support 37, the outer ring of the ball bearing 9 is pressed by the bearing outer ring pressure cover 13, and the roll driven gear 38 is installed on the roll driven gear support 39.

Claims

1. A high-precision, lightweight, three-axis stabilized platform, characterized by: It comprises a bias flow assembly (1), a pitch assembly (2) and a roll assembly (3); The deflector assembly (1) is mounted on the pitch assembly (2), and the two are connected by using the pitch shaft (27) and the bearing inner ring pressure cover (31) at both ends to press the inner ring of the ball bearing (9), and the pitch assembly (2) is mounted on the roll assembly (3), and the two are connected by using the bearing inner ring pressure cover (31) and the roll shaft (32) at both ends to press the inner ring of the ball bearing (9); The deflection flow assembly (1) comprises a deflection flow inner frame (4), a deflection flow outer frame upper frame (5), a deflection flow outer frame lower frame (6), a deflection flow bearing assembly (7), a first reducer drive assembly (8), a ball bearing (9), a three-axis fiber optic gyroscope (10), a first zero position proximity switch sensing element (11), a first zero position proximity switch (12), a bearing outer ring pressure cover (13), a deflection flow mechanical limit column (14), a synchronous transmission belt (15), a deflection flow driven gear (16), a pitch mechanical limit column (17), a pitch driven gear (18) and a first reducer drive assembly protective cover (19); the ball bearing (9) is installed in the deflection flow outer frame lower frame (6), and the outer ring of the ball bearing (9) is pressed by the bearing outer ring pressure cover (13); the deflection flow bearing assembly (7) is respectively installed between the deflection flow inner frame (4) and the deflection flow outer frame upper frame (5) and between the deflection flow inner frame (4) and the deflection flow outer frame. The first reducer drive assembly (8) is mounted on the lower frame (6) of the bias flow outer frame, and drives the bias flow driven gear (16) through a synchronous transmission belt (15); the bias flow mechanical limit column (14) is mounted in the lower frame (6) of the bias flow outer frame; the pitch mechanical limit column (17) is mounted in the lower frame (6) of the bias flow outer frame; the three-axis fiber optic gyroscope (10) is mounted in the lower frame (6) of the bias flow outer frame, and simultaneously senses the attitude, angular velocity and angular acceleration of the three axis systems in the inertial space; the first zero position proximity switch (12) is mounted in the lower frame (6) of the bias flow outer frame, and the control of the platform bias flow movement is achieved by sensing the real-time position of the first zero position proximity switch sensed component (11) during the rotation process; the first reducer drive assembly protective cover (19) is mounted on the first reducer drive assembly (8), and the pitch driven gear (18) is mounted on the lower frame (6) of the bias flow outer frame; The bias flow bearing assembly (7) comprises precision steel balls (20), a bearing outer ring steel sleeve (21), a bearing inner ring steel sleeve (22) and a bearing retainer (23); the bearing outer ring steel sleeve (21) is respectively mounted on the lower end surface of the inner ring of the bias flow outer frame upper frame (5) and the upper end surface of the inner ring of the bias flow outer frame lower frame (6); the bearing inner ring steel sleeve (22) is respectively mounted on the upper end surface and the lower end surface of the outer ring of the bias flow inner frame (4); two bearing retainers (23) are respectively mounted on two sets of bearing outer ring steel sleeves (21) and bearing inner ring steel sleeves (22); and the precision steel balls (20) are mounted in the bearing retainers (23); The pitch assembly (2) comprises a pitch axis (27), a second reducer drive assembly (28), a second zero position proximity switch (29), a pitch frame (30), a bearing inner ring pressure cover (31), a roll axis (32), a third zero position proximity switch (33), a third reducer drive assembly (34) and an upper housing (35); the pitch axis (27), the second reducer drive assembly (28), the second zero position proximity switch (29), the roll axis (32), the third zero position proximity switch (33), the third reducer drive assembly (34) and an upper housing (35); The component (34) and the upper shell (35) are respectively mounted on the pitch frame (30), and the bearing inner ring pressure cover (31) is respectively mounted on the pitch axis (27) and the roll axis (32) to press the inner ring of the ball bearing (9) tightly. The real-time position of the pitch driven gear (18) during the rotation process is sensed by the second zero position proximity switch (29) to achieve control of the pitch motion of the platform. The real-time position of the roll driven gear (38) during the rotation process is sensed by the third zero position proximity switch (33) to achieve control of the roll motion of the platform. The roll assembly (3) comprises a handle (36), a roll bearing support (37), a roll driven gear (38), a roll driven gear support (39), a roll frame (40), a roll mechanical limit column (41) and a shock absorber (42); the handle (36) is mounted on both sides of the roll frame (40), which is conducive to carrying the platform without damaging the structure; the roll bearing support (37), the roll driven gear support (39), the roll mechanical limit column (41) and the shock absorber (42) are respectively mounted on the roll frame (40); the shock absorber (42) can effectively isolate high-frequency vibration; the ball bearing (9) is mounted in the roll bearing support (37); the outer ring of the ball bearing (9) is pressed by the bearing outer ring pressure cover (13); and the roll driven gear (38) is mounted on the roll driven gear support (39); The first reducer drive assembly (8), the second reducer drive assembly (28) and the third reducer drive assembly (34) comprise a driving gear (24), a reducer (25) and a torque motor (26); the reducer (25) is mounted on the torque motor (26), the driving driving gear (24) is mounted on the reducer (25), and the torque motor (26) drives the driving gear (24) through the deceleration effect of the reducer (25); The upper bias flow outer frame (5), the lower bias flow outer frame (6) and the inner bias flow frame (4) are made of aviation super-hard aluminum material.

2. A high-precision, lightweight, three-axis stable platform according to claim 1, characterized in that: The bearing outer ring steel sleeve (21) and the bearing inner ring steel sleeve (22) are made of aviation steel material.

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