CN112399041B

CN112399041B - Video camera

Info

Publication number: CN112399041B
Application number: CN201910764181.8A
Authority: CN
Inventors: 张雪涛; 王岳
Original assignee: Hangzhou Hikvision Digital Technology Co Ltd
Current assignee: Hangzhou Hikvision Digital Technology Co Ltd
Priority date: 2019-08-19
Filing date: 2019-08-19
Publication date: 2022-07-15
Anticipated expiration: 2039-08-19
Also published as: CN112399041A

Abstract

The invention provides a camera, which comprises a motor, a controller, a memory and a magnetic sensor assembly, wherein the motor, the magnetic sensor assembly and the memory are in communication connection with the controller; the memory stores a plurality of executable programs; the controller acquires a target rotation angle of the motor and calls an executable program in the memory to drive the motor to rotate; the magnetic sensor assembly detects an actual rotation angle of the motor; the controller calls an executable program in the memory to compare the actual rotating angle with the target rotating angle, and the executable program in the memory is called according to the comparison result to feed back and adjust the rotating angle of the motor. According to the invention, the actual rotation angle of the motor is detected by the magnetic sensor assembly and fed back to the controller for comparison, and the controller drives the motor to rotate according to the comparison result so as to compensate or reset the lens, so that the movement precision of the lens is improved, and the shooting quality is improved.

Description

Video camera

Technical Field

The invention relates to the technical field of security and protection monitoring, in particular to a camera.

Background

The camera generally includes a motor and a reduction transmission mechanism, and the motor drives the lens to move horizontally and vertically through the reduction transmission mechanism, so as to realize multi-angle shooting of the lens. In order to detect whether the lens rotates to a preset angle, a stepping motor is generally used in the existing camera, the rotation angle of the stepping motor is obtained by acquiring the step number of the stepping motor and calculating according to a preset algorithm, and the actual rotation angle of the lens is directly represented by the rotation angle of the stepping motor.

Specifically, the existing camera is provided with an angle detection device including a sensor for detecting a rotation distance of a stepping motor and a controller. The sensor transmits the detected step number of the stepping motor to the controller, the controller calculates the rotation angle of the stepping motor according to a preset algorithm, and the rotation angle is regarded as the actual rotation angle of the lens.

However, since a speed reduction transmission mechanism needs to be arranged between the stepping motor and the lens to realize speed reduction and torque increase, and due to assembly errors, transmission errors and the like of the speed reduction transmission mechanism, an error exists between the actual rotation angle of the lens and the rotation angle of the stepping motor obtained through algorithm calculation, so that the rotation precision of the lens is difficult to ensure, and the shooting quality is affected.

Disclosure of Invention

The invention provides a camera, which aims to solve the technical problems that the rotation angle of a lens has errors, whether the lens rotates to a preset position cannot be determined, the movement precision of the lens is reduced, and the shooting quality is influenced due to assembly errors, transmission errors and the like of a speed reduction transmission mechanism of the conventional camera.

The camera comprises a motor, a controller, a memory and a magnetic sensor assembly, wherein the motor, the magnetic sensor assembly and the memory are all in communication connection with the controller; the memory stores a plurality of executable programs; the controller acquires a target rotation angle of the motor and calls an executable program in the memory to drive the motor to rotate; the magnetic sensor assembly detects an actual rotation angle of the motor; and the controller calls an executable program in the memory to compare the actual rotating angle with the target rotating angle, and calls the executable program in the memory to regulate the rotating angle of the motor in a feedback manner according to the comparison result.

The camera as described above, wherein the magnetic sensor assembly detects a real-time rotation angle of the motor during rotation of the motor; the controller calls the executable program in the memory to compare the real-time rotating angle of the motor with the target rotating angle, and calls the executable program in the memory to perform real-time feedback adjustment on the rotating angle of the motor according to the comparison result.

The camera as described above, wherein after the controller controls the motor to rotate according to the target rotation angle acquired by the controller, the magnetic sensor assembly detects and acquires the current rotation angle of the motor; the controller calls an executable program in the memory to compare the current rotating angle of the motor with the target rotating angle, and calls the executable program in the memory to regulate the rotating angle of the motor in a feedback mode according to the comparison result.

The camera as described above, wherein the invoking of the executable program in the memory according to the comparison result to feedback-adjust the rotation angle of the motor comprises: when the actual rotation angle is smaller than the target rotation angle, the controller calls an executable program in the memory to drive the motor to continue rotating along the current rotation direction until the actual rotation angle is consistent with the target rotation angle; and when the actual rotating angle is larger than the target rotating angle, the controller calls an executable program in the memory to drive the motor to rotate along the direction opposite to the current rotating direction until the actual rotating angle is consistent with the target rotating angle.

The camera as described above, wherein the controller calls the executable program in the memory according to the target rotation angle to send a driving signal to the motor to drive the motor to rotate; the driving signal is any one of a PWM signal, an analog signal and an SPI signal.

The camera further comprises a fixing frame and a speed reduction transmission mechanism, wherein the speed reduction transmission mechanism comprises a transmission shaft, a first end of the transmission shaft is connected with an output shaft of the motor, a second end of the transmission shaft is used for being connected with the lens, and the transmission shaft is arranged in a shaft hole formed in the fixing frame in a penetrating mode and can rotate relative to the fixing frame; the magnetic sensor assembly includes: the magnetic encoder and the magnet, one of the magnetic encoder and the magnet is fixed the first end of transmission shaft, another one of the magnetic encoder and the magnet is fixed on the mount, just the magnetic encoder with the magnet is followed the axis direction of transmission shaft has the clearance.

The camera as described above, wherein the speed reduction transmission mechanism includes a driving wheel, a driven wheel and a transmission belt for driving and connecting the driving wheel and the driven wheel, and the driving wheel is connected with the output shaft of the motor; the speed reduction transmission mechanism also comprises a rotating body and a bearing arranged in the shaft hole; the transmission shaft and the rotating body are integrally arranged; the driven wheel is connected with the rotating body through the bearing, and the rotating body is used for connecting the lens.

The camera as described above, wherein the magnet is a magnetic column, the camera further comprises a first bracket, one end of the first bracket is fixedly connected to the fixing frame, and the magnetic column is mounted at the other end of the first bracket; the magnetic encoder is arranged on the end face, facing the magnetic column, of the driven wheel, and the magnetic encoder and the magnetic column are coaxially arranged.

As above camera, wherein, first support includes first mounting panel, certainly the tip orientation of first mounting panel the mount extends and forms the connecting plate and certainly the tip of connecting plate deviates from first mounting panel extends and forms the second mounting panel, install on the first mounting panel the magnetic column, the second mounting panel with mount fixed connection.

The camera as described above, wherein a first fixing portion is disposed on a surface of the first mounting plate facing the fixing frame, and the first fixing portion is used for fixing the magnetic pillar.

The camera as described above, wherein the magnetic cylinder has a cylindrical structure; the first fixing part is a circular ring for accommodating the magnetic column.

The camera as claimed in the above, wherein the second mounting plate is provided with at least one first mounting hole; the fixing frame is provided with a fixing seat, and the fixing seat is provided with a first fixing column fixedly connected with the first mounting hole.

The camera as described above, wherein the camera further comprises a first circuit board on which the magnetic encoder and the controller are integrated; the end face of the driven wheel facing the magnetic column is provided with a mounting groove for fixing the first circuit board.

The camera as described above, wherein the first circuit board is provided with at least one first fixing hole, the bottom wall of the mounting groove is provided with at least one second fixing hole, and the second fixing holes correspond to the first fixing holes one to one; the camera further comprises at least one first fastener, and each first fastener penetrates through the corresponding first fixing hole and the corresponding second fixing hole to fix the first circuit board in the mounting groove.

The camera as described above, wherein the camera further includes a second bracket, one end of the second bracket is fixedly connected to the fixing frame, and the other end of the second bracket is mounted with the magnetic encoder; the magnet is a magnetic column, the magnetic column is arranged on the end face, facing the magnetic encoder, of the driven wheel, and the magnetic column and the magnetic encoder are coaxially arranged.

The camera as described above, wherein the transmission shaft is a hollow shaft, and the magnet is a magnetic ring; the camera further comprises a third support, one end of the third support is fixedly connected with the end face of the driven wheel, and the other end of the third support is provided with the magnetic ring; the fixing frame is provided with an installation part for installing the magnetic encoder; the magnetic encoder and the magnetic ring are eccentrically arranged.

The camera as described above, wherein the third bracket includes a first mounting ring, a limit ring disposed on the first mounting ring, and a second mounting ring disposed on the limit ring, the first mounting ring, the limit ring, and the second mounting ring are coaxial, and an outer diameter of the first mounting ring, an outer diameter of the limit ring, and an outer diameter of the second mounting ring decrease in this order; the first mounting ring is fixedly connected with the end face of the driven wheel; the magnetic ring is of a circular ring structure, and the magnetic ring is sleeved on the second mounting ring.

The camera as described above, wherein at least one second mounting hole is provided along a circumferential direction of an end surface of the driven wheel facing the magnetic encoder, at least one third mounting hole is provided along the circumferential direction of the first mounting ring, and the third mounting holes correspond to the second mounting holes one to one; the camera further comprises at least one second fastener, and the second fastener penetrates through the second mounting hole and the corresponding third mounting hole so as to fix the first mounting ring on the end face, facing the magnetic encoder, of the driven wheel.

The camera as described above, wherein the camera further comprises a second circuit board on which the magnetic encoder and the controller are integrated; the second circuit board is provided with at least one second fixing hole, the fixing frame is provided with at least one second fixing column, the second fixing columns correspond to the second fixing holes one to one, and the second fixing columns penetrate through the second fixing holes so as to fix the second circuit board on the fixing frame.

The camera as described above, wherein the transmission shaft is a hollow shaft, and the magnet is a magnetic ring; the camera also comprises a fourth support, one end of the fourth support is fixedly connected with the fixed frame, and the other end of the fourth support is provided with the magnetic ring; the magnetic encoder is arranged on the end face, facing the magnetic ring, of the driven wheel; the magnetic encoder and the magnetic ring are eccentrically arranged.

The camera as described above, wherein the magnetic encoder is disposed outside the magnetic loop.

The camera as described above, wherein the magnetic ring is a multi-pair pole magnetic ring.

The camera as described above, wherein the controller calls an executable program in the memory to compare the actual rotation angle with the target rotation angle, comprising: the controller performs linear correction on the received actual rotation angle to obtain a corrected actual rotation angle; and the controller calls an executable program in the memory to compare the corrected actual rotating angle with the target rotating angle, and calls the executable program in the memory to regulate the rotating angle of the motor in a feedback manner according to a comparison result.

According to the camera, the actual rotating angle of the motor is detected through the magnetic sensor assembly, the controller compares the actual rotating angle with the target rotating angle by calling the executable program in the memory, and the executable program in the memory is called according to the comparison result to drive the motor to rotate so as to compensate or reset the lens, so that the assembly error, the transmission error and the like of the speed reduction transmission mechanism are avoided, the movement precision of the lens is improved, and the shooting quality is improved.

In addition to the technical problems, technical features constituting technical solutions, and advantageous effects brought by the technical features of the technical solutions described above, other technical problems, technical features included in technical solutions, and advantageous effects brought by the technical features that can be solved by the camera provided by the present invention will be described in further detail in the detailed description of embodiments.

Drawings

Fig. 1 is a schematic electrical connection diagram of a camera according to an embodiment of the present invention;

fig. 2 is a schematic structural diagram of a camera according to a second embodiment of the present invention;

FIG. 3 is a schematic view of the relative positions of the magnetic cylinder and the magnetic encoder of FIG. 2;

fig. 4 is a schematic structural diagram of a camera according to a third embodiment of the present invention;

FIG. 5 is a schematic view of the relative positions of a single pair of pole magnetic rings and a magnetic encoder in FIG. 4;

FIG. 6 is a schematic diagram showing the relative positions of the multiple pairs of pole magnetic rings and the magnetic encoder in FIG. 4.

Description of reference numerals:

1: a rotating body; 11: a drive shaft;

2: a fixed mount; 21: a shaft hole; 22: a fixed seat;

3: a bearing;

4: a driven wheel; 41: mounting grooves;

5: a transmission belt;

61: a first circuit board; 62: a second circuit board;

7: a magnetic encoder;

8: a magnetic column;

9: a magnetic ring;

10: a first bracket; 110: a first mounting plate; 120: a connecting plate; 130: a second mounting plate; 131: a first mounting hole;

20: a third support; 210: a first mounting ring; 211: a third mounting hole; 220: a limiting ring; 230: a second mounting ring;

30: a motor;

40: a controller;

50: a memory;

60: a magnetic sensor assembly.

Detailed Description

Reference will now be made in detail to embodiments of the present invention, examples of which are illustrated in the accompanying drawings, wherein like or similar reference numerals refer to the same or similar elements or elements having the same or similar function throughout. The embodiments described below with reference to the drawings are illustrative and intended to be illustrative of the invention and are not to be construed as limiting the invention.

Fig. 1 is an electrical connection diagram of a camera according to an embodiment of the present invention.

Referring to fig. 1, an embodiment of the present invention provides a video camera including a motor 30, a controller 40, a memory 50, and a magnetic sensor assembly 60. The motor 30, the magnetic sensor assembly 60, and the memory 50 are all communicatively coupled to the controller 40, and the memory 50 has a number of executable programs stored therein. The controller 40 acquires a target rotation angle of the motor 30 and calls an executable program in the memory 50 to drive the motor 30 to rotate. The magnetic sensor assembly 60 detects the actual rotational angle of the motor 30. The controller 40 calls an executable program in the memory 50 to compare the magnitude of the actual rotation angle with the target rotation angle, and calls the executable program in the memory 50 to feedback-adjust the rotation angle of the motor 30 according to the comparison result.

Specifically, as shown in fig. 1, when the lens of the camera is driven to rotate by the motor 30, a user may preset a target rotation angle of the motor 30, or may automatically set the target rotation angle by a program, and then the controller 40 may acquire the set target rotation angle and call the executable program in the memory 50 to drive the motor 30 to rotate, and during or at the end of the rotation, the magnetic sensor assembly 60 may detect an actual rotation angle of the motor (which often does not coincide with the target rotation angle because of assembly errors or transmission errors of the camera, etc.). In order to ensure the lens rotation accuracy of the camera, that is, to make the actual rotation angle consistent with the target rotation angle, the controller 40 calls the executable program in the memory 50, and the executable program can compare the actual rotation angle with the target rotation angle when running, and call the executable program in the memory 50 to feed back and adjust the rotation angle of the motor 30 according to the comparison result, so as to ensure that the final actual rotation angle of the motor 30 is consistent with the target rotation angle, thereby effectively ensuring the rotation accuracy of the lens and improving the shooting quality of the camera.

It should be noted that, the specific structure of the memory 50 is not limited, for example, the memory 50 may be a Random Access Memory (RAM), a read-only memory (ROM), an erasable programmable read-only memory (EPROM or flash memory), a portable compact disc read-only memory (CD-ROM), an optical memory, a magnetic memory, or any suitable combination thereof, and the specific structure may be selected according to actual needs.

In order to calibrate the rotation angle of the motor 30 in real time, the magnetic sensor assembly 60 detects the real-time rotation angle of the motor 30 during the rotation of the motor 30, so that the controller 40 can call the executable program in the memory 50 in real time to compare the real-time rotation angle of the motor 30 with the target rotation angle, and call the executable program in the memory 50 to feed back and adjust the rotation angle of the motor 30 in real time according to the comparison result, thereby ensuring the real-time rotation angle of the motor 30 to be consistent with the target rotation angle, effectively ensuring the rotation precision of the lens, and improving the shooting quality of the camera.

It should be understood that, in the present embodiment, the preset target rotation angle should also be a series of target rotation angles corresponding to different times, so that, for different times, the rotation angle at the time can be compared with the target rotation angle in real time, and the rotation angle of the motor at the time can be adjusted according to the comparison result.

As a preferable feedback calibration timing, after the controller 40 controls the motor 30 to rotate according to the target rotation angle acquired by the controller 40, the magnetic sensor assembly 60 detects and acquires the current rotation angle of the motor 30. Then, the controller 40 may call the executable program in the memory 50 to compare the current rotation angle of the motor 30 with the target rotation angle, and call the executable program in the memory 50 to feedback and adjust the rotation angle of the motor 30 according to the comparison result, so as to ensure that the final rotation angle of the motor 30 is consistent with the target rotation angle, thereby effectively ensuring the rotation precision of the lens and improving the shooting quality of the camera.

In the present embodiment, by detecting the current rotation angle of the motor after the controller 40 controls the motor 30 to rotate according to the target rotation angle acquired by the controller 40, the amount of processing of the controller 40 can be effectively reduced (for example, the number of times the controller 40 accesses the memory 50, the number of times the executable program is called, and the amount of calculation of the controller 40 can be reduced), and thus the power consumption of the camera can be effectively reduced.

It should be noted that there is no limitation on how the controller 40 calls up the executable program in the memory 50 to feedback-adjust the rotation angle of the motor 30 according to the comparison result, as long as it can ensure that the feedback-adjusted rotation angle of the motor is consistent with the target rotation angle.

Specifically, when the actual rotation angle of the motor is smaller than the target rotation angle, the controller 40 calls the executable program in the memory 50 to drive the motor 30 to continue rotating in the current rotation direction until the actual rotation angle of the motor 30 is consistent with the target rotation angle. On the contrary, when the actual rotation angle of the motor 30 is greater than the target rotation angle, at this time, the controller 40 calls the executable program in the memory 50 to drive the motor 30 to rotate in the direction opposite to the current rotation direction until the actual rotation angle of the motor 30 is consistent with the target rotation angle.

It is understood that, in the above-described embodiment, the controller 40 calls the executable program in the memory 50 according to the target rotation angle to send a driving signal to the motor 30 to drive the motor 30 to rotate; the driving signal is any one of a PWM signal, an analog signal and an SPI signal. In practical applications, the controller 40 sends different control signals according to different types of drivers of the motor 30, which is not limited in the embodiment of the present invention.

According to the camera, the actual rotation angle of the motor is detected through the magnetic sensor assembly, the controller compares the actual rotation angle with the target rotation angle by calling the executable program in the memory, and calls the executable program in the memory according to the comparison result to drive the motor to rotate so as to compensate or reset the lens, so that the assembly error, the transmission error and the like of the speed reduction transmission mechanism are avoided, the movement precision of the lens is improved, and the shooting quality is improved.

Fig. 2 is a schematic structural diagram of a camera according to a second embodiment of the present invention; FIG. 3 is a schematic view of the relative positions of the magnetic cylinder and the magnetic encoder of FIG. 2; fig. 4 is a schematic structural diagram of a camera according to a third embodiment of the present invention; FIG. 5 is a schematic view of the relative positions of a single pair of pole magnetic rings and a magnetic encoder in FIG. 4; FIG. 6 is a schematic diagram showing the relative positions of the multiple pairs of pole magnetic rings and the magnetic encoder in FIG. 4.

Referring to fig. 2, the camera provided by the second embodiment of the present invention further includes a fixing frame 2 and a deceleration transmission mechanism, the deceleration transmission mechanism includes a transmission shaft 11, a first end of the transmission shaft 11 is connected to an output of the motor 30, a second end of the transmission shaft 11 is used for connecting to a lens, and the transmission shaft 11 is inserted into a shaft hole 21 formed in the fixing frame 2 and can rotate relative to the fixing frame 2; the magnetic sensor assembly 60 includes a magnetic encoder 7 and a magnet, one of the magnetic encoder 7 and the magnet is fixed to the first end of the drive shaft 11, the other of the magnetic encoder 7 and the magnet is fixed to the fixing frame 2, and the magnetic encoder 7 and the magnet have a gap in the axial direction of the drive shaft.

Specifically, the fixing frame 2 is used for fixedly supporting the motor 30, and may include a fixing housing, the fixing housing may be provided with a shaft hole 21 corresponding to the position of the transmission shaft 11, and the transmission shaft 11 of the reduction transmission mechanism is inserted into the shaft hole 21. The stationary housing may also be provided with a mounting 22 for fixing the magnetic encoder 7 or the magnet. The embodiment of the present invention does not limit the specific structure of the fixing frame 2.

The speed reduction transmission mechanism comprises a transmission shaft 11, wherein a first end of the transmission shaft 11 is in transmission connection with an output shaft of the motor 30, and a second end of the transmission shaft 11 is used for being connected with the lens and transmitting power output by the motor 30 to the lens so as to enable the lens to rotate to a target angle position. The transmission shaft 11 may be a single shaft, one end of which is used for being in transmission connection with the motor 30, and the other end of which is connected with the lens; alternatively, the transmission shaft 11 may include two sections of shafts, and the two sections of shafts are connected by a coupling. The drive shaft 11 may be a solid shaft; alternatively, the drive shaft 11 may be a hollow shaft, which is used in a camera where the drive shaft 11 needs to be threaded. The reduction transmission mechanism can also comprise a gear transmission mechanism, the reduction transmission mechanism can also comprise a belt transmission mechanism, and the reduction transmission mechanism can also comprise other transmission mechanisms. The reduction transmission mechanism of the embodiment of the invention is preferably a belt transmission mechanism.

The magnetic encoder 7 and the magnet have a gap therebetween in the axial direction of the transmission shaft 11, and are capable of relative rotation. In some embodiments, referring to fig. 4, the magnetic encoder 7 is mounted on a stationary mounting frame 2 and the magnet is mounted on a first end of a drive shaft 11 that moves in rotation. In other embodiments, referring to fig. 2, the magnetic encoder 7 is mounted on a first end of a drive shaft 11 that moves in rotation, and the magnet is mounted on a stationary mounting frame 2. The magnetic encoder 7 may be an existing magnetic encoder structure, which is usually a chip structure, and during the actual installation process, the magnetic encoder 7 may be integrated on a circuit board of the camera, which is fixed to the first end of the transmission shaft 11 or the fixing frame 2.

In the use, according to the instruction manual of magnetic encoder 7, make and satisfy certain condition between magnetic encoder 7 and the magnet, as shown in fig. 2, when motor 30 drive transmission shaft 11 rotated, transmission shaft 11 drove magnetic encoder 7 and rotates together, and like this, relative rotation takes place between magnetic encoder 7 and the magnet, and magnetic encoder 7 senses magnetic field and changes, can detect the actual turned angle of transmission shaft 11 according to hall effect magnetic encoder 7, the actual turned angle of camera lens promptly to send the testing result for controller 40. The controller 40 generates a target rotation angle of the motor 30 according to the control command, compares the target rotation angle with an actual rotation angle, and adjusts the position of the transmission shaft 11, that is, adjusts the position of the lens according to the comparison result.

Illustratively, the controller 40 controls the motor 30 to operate after receiving the control command, and the lens rotates by driving the driving shaft 11, but the lens does not rotate to the preset position. For example, the controller 40 controls the motor 30 to operate according to the control command, and drives the lens to rotate by a desired angle of 45 degrees. In 11 rotation processes of transmission shaft, take place relative rotation between magnetic encoder 7 and the magnet, magnetic encoder 7 senses magnetic field and changes, can detect the actual turned angle of transmission shaft 11 according to hall effect magnetic encoder 7, and the actual turned angle of transmission shaft 11 that magnetic encoder 7 detected is 43 degrees, and the camera lens has actually rotated 43 degrees promptly. The magnetic encoder 7 sends the actual rotation angle 43 degrees to the controller 40, the controller 40 compares the actual rotation angle 43 degrees with the expected rotation angle 45 degrees, and the comparison shows that the lens rotates by two degrees less, at this time, the controller 40 controls the motor 30 to continue to operate according to the comparison result, and drives the lens to continue to rotate by two degrees through the transmission shaft 11. It is understood that the difference between the expected rotation angle and the actual rotation angle is smaller than a threshold value, which is obtained by simulation based on the magnetic encoder, the motor, the controller, the reduction transmission mechanism, and the like, and is not limited herein.

It is to be understood that the magnet may be a ru ferrite magnet, a ru ibbon magnet, or the like, which is not limited in the embodiments of the present invention. The magnet can be a magnetic column, a magnetic ring and the like, and the specific shape of the magnet can be adaptively designed according to the specific structure of the camera so as to be adaptive to the existing structure of the camera.

According to the camera provided by the embodiment of the invention, one of the magnetic encoder and the magnet is arranged at the first end of the transmission shaft of the speed reduction transmission mechanism, the other of the magnetic encoder and the magnet is arranged on the fixed frame, the magnetic encoder and the magnet rotate relatively, the magnetic encoder detects the rotation angle of the transmission shaft by using the Hall effect, whether the lens rotates to an expected position or not is accurately fed back, the assembly error, the transmission error and the like of the speed reduction transmission mechanism are avoided, the lens is compensated or reset according to the feedback result, the movement precision of the lens is favorably improved, and the shooting quality is improved.

Because the belt transmission has the advantage of smooth transmission, the speed reduction transmission mechanism comprises the belt transmission mechanism. Specifically, the reduction transmission mechanism includes a driving wheel (not shown) for connecting with an output shaft of the motor 30, a driven wheel 4, and a transmission belt 5 for drivingly connecting the driving wheel and the driven wheel 4.

The driving wheel and the output shaft of the motor can be connected through a bearing, and the driving wheel and the driven wheel 4 are in transmission connection through a transmission belt 5.

The transmission belt 5 may be a flat belt, a V-belt, a circular belt, a toothed belt, etc., and preferably, the transmission belt 5 is a toothed belt to reduce noise. Correspondingly, the driving wheel and the driven wheel 4 are provided with tooth-shaped structures.

Furthermore, the speed reduction transmission mechanism also comprises a rotating body 1 and a bearing 3 arranged in the shaft hole 21, and the transmission shaft 11 and the rotating body 1 are integrally arranged; the driven wheel 4 is connected with the rotating body 1 through a bearing 3, and the rotating body 1 is used for connecting a lens.

Specifically, the transmission shaft 11 is provided integrally with the rotor 1, and the transmission shaft 11 is connected with the inner ring of the bearing 3. And the end surface of the driven wheel 4 close to the bearing 3 is provided with a circular groove for connecting with the outer ring of the bearing 3, and the end surface of the driven wheel 4 departing from the bearing 3 is used for mounting a magnetic encoder 7 or a magnet. For example, with reference to fig. 2, the end face of the driven wheel 4 facing away from the bearing 3 is provided with a recess for accommodating a circuit board 6, which matches the shape of the circuit board 6, in which recess the circuit board 6 is fixed by means of screws.

Of course, the transmission shaft 11 may also include two parts, one part of which is integrally disposed with the rotating body 1, and the other part of which is integrally disposed with the driven wheel 4, that is, one end of the rotating body 1 away from the lens is provided with a protruding shaft segment, and one end of the driven wheel 4 close to the rotating body 1 is provided with another protruding shaft segment, and the two shaft segments are connected through the bearing 3.

The rotating body 1 may be provided with a mounting seat to connect with a lens, and the embodiment of the present invention does not limit the specific structure of the rotating body 1.

The power output process of the motor 30 is as follows: the output shaft of motor 30 rotates, drives speed reduction drive mechanism's action wheel and rotates, under the transmission effect of drive belt 5, is rotary motion from driving wheel 4, and under the effect of bearing 3, rotor 1 drives the camera lens and rotates to reach preset shooting angle.

The shape of the magnet may be varied, for example, the magnet may be of a cylindrical configuration, or the magnet may be of a circular configuration.

In some embodiments, referring to fig. 2 and 3, the magnet is a magnetic pillar 8, in this case, the camera further includes a first bracket 10, one end of the first bracket 10 is fixedly connected to the fixing frame 2, and the other end of the first bracket 10 is provided with the magnetic pillar 8; the magnetic encoder 7 is arranged at the first end of the transmission shaft 11, and the magnetic encoder 7 and the magnetic column 8 are coaxially arranged.

In the embodiment, the magnetic column 8 is fixedly connected with the fixed frame 2 through the first bracket 10, and is static relative to the fixed frame; the magnetic encoder 7 is arranged on the end face, facing the magnetic column 8, of the driven wheel 4 and rotates relative to the fixed frame 2.

Further, the first bracket 10 includes a first mounting plate 110, a connecting plate 120 extending from an end of the first mounting plate 110 toward the fixing frame 2, and a second mounting plate 130 extending from an end of the connecting plate 120 away from the first mounting plate 110, wherein the first mounting plate 110 is mounted with a magnetic pillar 8, and the second mounting plate 130 is fixedly connected with the fixing frame 4.

Wherein the first mounting plate 110 and the second mounting plate 130 are respectively located at two sides of the connecting plate 120, the first bracket 10 forms a zigzag structure, and preferably, the first mounting plate 110, the connecting plate 120 and the second mounting plate 130 are an integrally formed integral piece. The first mounting plate 110 is used for mounting the magnetic column 8, for example, a groove is arranged on an end surface of the first mounting plate 110 facing the fixing frame 2, and the magnetic column 8 is in interference connection with the groove; for another example, a first fixing portion (not shown) is disposed on a surface of the first mounting plate 110 facing the fixing frame 4, and the first fixing portion is used for fixing the magnetic pillar 8. The first fixing portion may be a circular ring fixed on a surface of the first mounting plate 110 facing the fixing frame 4, and in this case, the magnetic pillar 8 has a cylindrical structure, and the magnetic pillar 8 of the cylindrical structure is accommodated in the circular ring. Of course, the magnetic pillar 8 may also be a pillar structure with other shapes, and the size of the magnetic pillar 8 is adapted to the existing structure of the camera, which is not limited herein in the embodiment of the present invention.

It will be appreciated that the first support 10 is not limited to that shown in figure 2 in order to accommodate different camera configurations.

Further, the second mounting plate 130 is provided with at least one first mounting hole 131, the fixing bracket 4 is provided with a fixing base 22, and the fixing base 22 is provided with a first fixing column (not shown) fixedly connected with the first mounting hole 131. For example, as shown in fig. 2, the second mounting plate 130 may be provided with four first mounting holes 131, the four first mounting holes 131 form a diamond pattern, and correspondingly, the fixing base 22 is also provided with four first fixing columns, and the four first fixing columns correspond to the four first mounting holes 131 in position.

With continued reference to fig. 2, the video camera of the embodiment of the present invention further includes a first circuit board 61, and the magnetic encoder 7 is integrated on the first circuit board 61. The end surface of driven wheel 4 facing magnetic pole 8 is provided with mounting groove 41 for fixing first circuit board 61. The first circuit board 61 may be a PCB board or an FPC board, which is not limited herein. The controller 40 may be further integrated on the first circuit board 61, and the magnetic encoder 7 and the controller 40 are in communication connection through bus signals or other signals, which is not limited in the embodiment. The shape of the first circuit board 61 may be various, and for example, the shape of the first circuit board 61 may be as shown in fig. 2. For different models of camera structures, the shape and size of the first circuit board 61 are different, that is, the shape and size of the first circuit board 61 are adapted to the specific structure of the camera, which is not limited in the embodiment of the present invention.

In order to fix the first circuit board 61 in the mounting groove 41, as shown in fig. 2, at least one first fixing hole (not shown) is provided on the first circuit board 61, and correspondingly, at least one second fixing hole (not shown) is provided on the bottom wall of the mounting groove 41, and each second fixing hole corresponds to one first fixing hole. The camera of the present embodiment further includes first fastening members (not shown), each of which is inserted into the corresponding first fixing hole and the second fixing hole, so that the first circuit board 61 can be fixed in the mounting groove 41. For example, as shown in fig. 2, four first fixing holes may be provided on the first circuit board 61, and correspondingly, four second fixing holes may also be provided on the mounting groove 41. The number and arrangement of the first fixing holes and the second fixing holes are not limited in the embodiment of the invention.

In other embodiments, the magnet is a magnetic pillar 8, and the magnetic pillar 8 is disposed at the first end of the transmission shaft 11; the camera further comprises a second support (not shown in the figure), one end of the second support is fixedly connected with the fixing frame 2, the other end of the second support is provided with a magnetic encoder 7, and the magnetic encoder 7 and the magnetic column 8 are coaxially arranged.

This embodiment differs from the previous one in that the magnetic cylinder 8 is arranged on the end face of the driven wheel 4 facing the magnetic encoder 7, which rotates relative to the fixed frame 2; the magnetic encoder 7 is arranged on the fixed frame 2 and is stationary relative to the fixed frame 2.

In this embodiment, the second stent may be a stent of zigzag structure. One end of the second support is provided with a fixing hole fixedly connected with the first circuit board 61, and the other end of the second support is provided with a fixing hole fixedly connected with the fixing frame 2. The embodiment of the present invention does not limit the specific structure of the second bracket, and a person skilled in the art can design the structure of the second bracket according to the existing structural adaptability of the camera.

In the above two embodiments, the magnet is a magnetic pillar 8, and the magnetic pillar 8 is disposed coaxially with the magnetic encoder 7. The structure is suitable for the camera of the pan-tilt without threading requirement at the position of the transmission shaft 11, and the whole layout space is compact.

It should be understood that the magnetic cylinder 8 is coaxial with the magnetic encoder 7, for example, the coaxiality is ± 0.25mm, the magnetic cylinder 8 and the magnetic encoder 7 are also required to be arranged in parallel, and the deviation of the parallel of the magnetic cylinder 8 and the magnetic encoder 7 is within 5 °, for example, the deviation of the parallel of the magnetic cylinder 8 and the magnetic encoder 7 is 3 °. Of course, the coaxial and parallel installation requirements of the magnetic pole 8 and the magnetic encoder 7 are not limited thereto, and those skilled in the art can install the magnetic pole according to the specification of the magnetic encoder 7 in particular.

However, the transmission shaft for horizontal rotation of the pan-tilt of some cameras generally has threading requirements, and in this case, a threading space needs to be reserved. In this case, the magnet may have a magnetic ring structure.

In some embodiments, referring to fig. 4, the transmission shaft 11 is a hollow shaft, and the magnet is a magnetic ring 9; the camera also comprises a third bracket 20, one end of the third bracket 20 is fixedly connected with the first end of the transmission shaft 11, and the other end of the third bracket 20 is provided with a magnetic ring 9; the fixed frame 2 is provided with a mounting part for mounting the magnetic encoder 7; the magnetic encoder 7 and the magnetic ring 9 are eccentrically arranged.

In the embodiment, the magnetic ring 9 is fixedly connected with the driven wheel 4 through a third bracket 20, and rotates relative to the fixed bracket 2; the magnetic encoder 7 is fixedly connected with the fixed frame 2 and is static relative to the fixed frame 2.

Further, the third bracket 20 includes a first mounting ring 210, a limiting ring 220 disposed on the first mounting ring 210, and a second mounting ring 230 disposed on the limiting ring 220, and the first mounting ring 210, the limiting ring 220, and the second mounting ring 230 are coaxial, and the outer diameters of the first mounting ring 210, the limiting ring 220, and the second mounting ring 230 decrease in sequence; the first mounting ring 210 is fixedly connected with the end face of the driven wheel 4; the magnetic ring 9 is a circular ring structure, and the magnetic ring 9 of the circular ring structure is sleeved on the second mounting ring 230.

It should be understood that the magnetic ring 9 may also be an annular structure with other shapes, and those skilled in the art may design the specific structure of the magnetic ring 9 according to the existing structure adaptability of the camera, and the embodiment of the present invention is not limited herein.

Preferably, the first mounting ring 210, the stop collar 220, and the second mounting ring 230 are integrally formed as a single piece.

Furthermore, the end surface of the driven wheel 4 facing the magnetic encoder 7 is provided with at least one second mounting hole along the circumferential direction thereof, the first mounting ring 210 is provided with at least one third mounting hole 211 along the circumferential direction thereof, and the third mounting holes 211 correspond to the second mounting holes one to one; the camera further comprises at least one second fastener (not shown) passing through the second mounting hole and its corresponding third mounting hole 211 to fix the first mounting ring 210 to the end surface of the driven wheel 4 facing the magnetic encoder 7. For example, referring to fig. 4, a groove is formed in an end surface of the driven wheel 4 facing the magnetic encoder 7, four second mounting holes are formed in a bottom wall of the groove, and the four second mounting holes are uniformly arranged at intervals along a circumferential direction of the driven wheel 4; correspondingly, four third mounting holes 211 are formed in the first mounting ring 210, and the third mounting holes 211 correspond to the second mounting holes one to one. Of course, the number of the second mounting holes and the number of the third mounting holes 211 are not limited in the embodiment of the present invention.

The camera provided by the embodiment of the present invention further includes a second circuit board 62, and the magnetic encoder 7 is integrated on the second circuit board 62, in order to fix the second circuit board 62 on the fixing frame 2, at least one second fixing hole (not shown) is provided on the second circuit board 62, at least one second fixing column (not shown) is provided on the fixing frame 2, and the second fixing columns correspond to the second fixing holes one-to-one, and the second fixing columns are inserted into the second fixing holes to fix the second circuit board 62 on the fixing frame 2.

The second circuit board 62 may be a PCB or an FPC, which is not limited herein. The controller 40 is integrated on the second circuit board 62. The shape of the second circuit board 62 may be various, for example, the shape of the second circuit board 62 may be as shown in fig. 4. The second circuit board 62 is shaped and sized to fit the existing structure of the camera, which is not limited in the embodiment of the present invention.

In other embodiments, the transmission shaft 11 is a hollow shaft, and the magnet is a magnetic ring 9; the camera also comprises a fourth bracket (not shown in the figure), one end of the fourth bracket is fixedly connected with the fixed frame 2, and the other end of the fourth bracket is provided with a magnetic ring 9; the magnetic encoder 7 is arranged at the first end of the transmission shaft 11; the magnetic encoder 7 and the magnetic ring 9 are eccentrically arranged.

The difference between this embodiment and the above embodiment is that the magnetic ring 9 is fixedly connected with the fixed frame 2 through a fourth bracket, and is stationary relative to the fixed frame 2; the magnetic encoder 7 is mounted on the end face of the driven wheel 4 facing the magnetic ring 9 and rotates relative to the fixed frame 2.

The skilled person can design the specific structure of the fourth bracket according to the existing structure of the camera to adapt to the existing structure of the camera, which is not limited herein. In the two embodiments, the magnet is a magnetic ring 9, a space is reserved for threading, and the magnetic encoder 7 and the magnetic ring 9 are arranged eccentrically.

Further, magnetic encoder 7 sets up in the outside of magnetic ring 9, further avoids influencing the threading.

Referring to fig. 5, the magnetic ring 9 may be a single pair of pole magnetic ring, i.e. the magnetic ring 9 has a pair of S-pole and N-pole. In order to improve the moving accuracy of the lens and the resolution of the camera as a whole, the magnetic ring 9 is preferably a multi-pole magnetic ring, that is, the magnetic ring 9 has a plurality of pairs of S poles and N poles, for example, referring to fig. 6, the magnetic ring 9 has five pairs of S poles and N poles. The embodiment of the invention does not limit the number of pole pairs of the magnetic ring 9.

The magnetic encoder 7 and the controller may be connected wirelessly or through a wire, which is not limited in the embodiment of the present invention. For example, when the motor is out of step or the device is in a static state, the angle deviation and the magnetic field change due to external force, so that the magnetic encoder 7 senses the magnetic field change to generate an electric signal, converts the electric signal into a communicable signal and sends the signal to the controller, and the controller controls the motor to drive the speed reduction transmission mechanism according to the signal, so that the lens rotates by a corresponding angle and rotates to a preset position.

Considering the non-linearity of the angular displacement output by the magnetic encoder 7 when the magnetic encoder 7 and the magnetic ring 9 are eccentrically arranged, the controller 40 calls an executable program in the memory 50 to compare the actual rotation angle with the target rotation angle, and the method comprises the following steps:

the controller 40 performs linear correction on the received actual rotation angle to obtain a corrected actual rotation angle;

the controller 40 calls the executable program in the memory 50 to compare the corrected actual rotation angle with the target rotation angle, and calls the executable program in the memory 50 to feed back and adjust the rotation angle of the motor 30 according to the comparison result, so that whether the lens rotates to the preset position can be further accurately fed back, the assembly error, the transmission error and the like of the speed reduction transmission mechanism are avoided, the movement precision of the lens is favorably improved, and the shooting quality is improved.

In the description above, references to the description of the term "one embodiment," "some embodiments," "an example," "a specific example," or "some examples," etc., mean that a particular feature, structure, material, or characteristic described in connection with the embodiment or example is included in at least one embodiment or example of the invention. In this specification, the schematic representations of the terms used above are not necessarily intended to refer to the same embodiment or example. Furthermore, the particular features, structures, materials, or characteristics described may be combined in any suitable manner in any one or more embodiments or examples. Furthermore, various embodiments or examples and features of different embodiments or examples described in this specification can be combined and combined by one skilled in the art without contradiction.

Finally, it should be noted that: the above embodiments are only used to illustrate the technical solution of the present invention, and not to limit the same; while the invention has been described in detail and with reference to the foregoing embodiments, it will be understood by those skilled in the art that: the technical solutions described in the foregoing embodiments may still be modified, or some or all of the technical features may be equivalently replaced; and these modifications or substitutions do not depart from the spirit of the corresponding technical solutions of the embodiments of the present invention.

Claims

1. A camera, comprising: the magnetic sensor comprises a motor, a controller, a memory and a magnetic sensor assembly, wherein the motor, the magnetic sensor assembly and the memory are all in communication connection with the controller; the memory stores a plurality of executable programs;

the controller acquires a target rotation angle of the motor and calls an executable program in the memory to drive the motor to rotate;

the magnetic sensor assembly detects an actual rotation angle of the motor;

the controller calls an executable program in the memory to compare the actual rotating angle with the target rotating angle, and calls the executable program in the memory to regulate the rotating angle of the motor in a feedback mode according to a comparison result;

the controller calls an executable program in the memory according to the target rotation angle to send a driving signal to the motor so as to drive the motor to rotate;

the camera also comprises a fixed frame and a speed reduction transmission mechanism; the speed reduction transmission mechanism comprises a driving wheel and a driven wheel;

the magnetic sensor assembly includes: a magnetic encoder and a magnet; the magnet is a magnetic column;

the camera also comprises a first bracket, one end of the first bracket is fixedly connected with the fixed frame, and the other end of the first bracket is provided with the magnetic column;

the magnetic encoder is arranged on the end face, facing the magnetic column, of the driven wheel, and is coaxially arranged with the magnetic column;

or

The camera also comprises a second bracket, one end of the second bracket is fixedly connected with the fixed frame, and the other end of the second bracket is provided with the magnetic encoder;

the magnetic column is arranged on the end face, facing the magnetic encoder, of the driven wheel, and the magnetic column and the magnetic encoder are coaxially arranged.

2. The camera of claim 1, wherein the magnetic sensor assembly detects a real-time rotational angle of the motor during rotation of the motor;

the controller calls the executable program in the memory to compare the real-time rotating angle of the motor with the target rotating angle, and calls the executable program in the memory to perform real-time feedback adjustment on the rotating angle of the motor according to the comparison result.

3. The camera according to claim 1, wherein after the controller controls the motor to rotate according to the target rotation angle acquired by the controller, the magnetic sensor assembly detects and acquires a current rotation angle of the motor;

the controller calls an executable program in the memory to compare the current rotating angle of the motor with the target rotating angle, and calls the executable program in the memory to regulate the rotating angle of the motor in a feedback mode according to a comparison result.

4. The camera of claim 3, wherein said invoking an executable program in said memory to feedback adjust the rotation angle of said motor based on the comparison comprises:

when the actual rotation angle is smaller than the target rotation angle, the controller calls an executable program in the memory to drive the motor to continue rotating along the current rotation direction until the actual rotation angle is consistent with the target rotation angle;

and when the actual rotating angle is larger than the target rotating angle, the controller calls an executable program in the memory to drive the motor to rotate along the direction opposite to the current rotating direction until the actual rotating angle is consistent with the target rotating angle.

5. The camera according to any one of claims 1 to 4, wherein the drive signal is any one of a PWM signal, an analog signal, and an SPI signal.

6. The camera according to claim 1, wherein the reduction transmission mechanism includes a transmission shaft, a first end of the transmission shaft is connected to an output shaft of the motor, a second end of the transmission shaft is used for connecting to the lens, and the transmission shaft is inserted into a shaft hole formed in the fixing frame and can rotate relative to the fixing frame;

one of the magnetic encoder and the magnet is fixed at the first end of the transmission shaft, the other of the magnetic encoder and the magnet is fixed on the fixing frame, and a gap is formed between the magnetic encoder and the magnet along the axial direction of the transmission shaft.

7. The camera of claim 6, wherein the reduction gear mechanism comprises a transmission belt for drivingly connecting the driving wheel and the driven wheel, the driving wheel being connected to an output shaft of the motor;

the speed reduction transmission mechanism also comprises a rotating body and a bearing arranged in the shaft hole; the transmission shaft and the rotating body are integrally arranged; the driven wheel is connected with the rotating body through the bearing, and the rotating body is used for connecting the lens.

8. The camera of claim 1, wherein the first bracket comprises a first mounting plate, a connecting plate extending from an end of the first mounting plate toward the mount, and a second mounting plate extending from an end of the connecting plate away from the first mounting plate, wherein the magnetic pillar is mounted on the first mounting plate, and the second mounting plate is fixedly connected to the mount.

9. The camera of claim 8, wherein a first fixing portion is disposed on a surface of the first mounting plate facing the fixing frame, and the first fixing portion is configured to fix the magnetic pillar.

10. The camera of claim 9, wherein the magnetic cylinder is a cylindrical structure; the first fixing part is a circular ring for accommodating the magnetic column.

11. The camera of claim 10, wherein the second mounting plate is provided with at least one first mounting hole;

the fixing frame is provided with a fixing seat, and the fixing seat is provided with a first fixing column fixedly connected with the first mounting hole.

12. The camera of any of claims 1, 8-11, further comprising a first circuit board, the magnetic encoder and the controller being integrated on the first circuit board;

the end face of the driven wheel facing the magnetic column is provided with a mounting groove for fixing the first circuit board.

13. The camera of claim 12, wherein the first circuit board is provided with at least one first fixing hole, the bottom wall of the mounting groove is provided with at least one second fixing hole, and the second fixing holes correspond to the first fixing holes one to one;

the camera further comprises at least one first fastening piece, and each first fastening piece penetrates through the corresponding first fixing hole and the corresponding second fixing hole so as to fix the first circuit board in the mounting groove.

14. A camera, comprising: the magnetic sensor comprises a motor, a controller, a memory and a magnetic sensor assembly, wherein the motor, the magnetic sensor assembly and the memory are all in communication connection with the controller; the memory stores a plurality of executable programs;

the magnetic sensor assembly detects an actual rotation angle of the motor;

the camera also comprises a fixed frame and a speed reducing transmission mechanism, wherein the speed reducing transmission mechanism comprises a driving wheel and a driven wheel; the speed reduction transmission mechanism further comprises a transmission shaft, a first end of the transmission shaft is connected with an output shaft of the motor, a second end of the transmission shaft is used for being connected with the lens, and the transmission shaft penetrates through a shaft hole formed in the fixing frame and can rotate relative to the fixing frame; the transmission shaft is a hollow shaft;

the magnetic sensor assembly includes: a magnetic encoder and a magnet; the magnet is a magnetic ring;

the camera further comprises a third support, one end of the third support is fixedly connected with the end face of the driven wheel, and the other end of the third support is provided with the magnetic ring;

the fixing frame is provided with an installation part for installing the magnetic encoder;

the magnetic encoder and the magnetic ring are eccentrically arranged;

or

The camera also comprises a fourth support, one end of the fourth support is fixedly connected with the fixing frame, and the other end of the fourth support is provided with the magnetic ring;

the magnetic encoder is arranged on the end face, facing the magnetic ring, of the driven wheel;

the magnetic encoder and the magnetic ring are eccentrically arranged.

15. The camera of claim 14, wherein during rotation of said motor, said magnetic sensor assembly detects a real-time rotational angle of said motor;

16. The camera according to claim 14, wherein after the controller controls the motor to rotate according to the target rotation angle acquired by the controller, the magnetic sensor assembly detects and acquires a current rotation angle of the motor;

the controller calls an executable program in the memory to compare the current rotating angle of the motor with the target rotating angle, and calls the executable program in the memory to regulate the rotating angle of the motor in a feedback mode according to the comparison result.

17. The camera of claim 16, wherein said invoking an executable program in said memory to feedback adjust the rotation angle of said motor based on the comparison comprises:

18. A camera according to any one of claims 14 to 17, wherein the drive signal is any one of a PWM signal, an analog signal, and an SPI signal.

19. The camera of claim 14, wherein one of the magnetic encoder and the magnet is fixed to a first end of the drive shaft, the other of the magnetic encoder and the magnet is fixed to the fixing bracket, and the magnetic encoder and the magnet have a gap in an axial direction of the drive shaft.

20. The camera of claim 19, wherein the reduction gear mechanism comprises a drive belt drivingly connecting the drive wheel and the driven wheel, the drive wheel being connected to an output shaft of the motor;

21. The camera of claim 14, wherein the third bracket comprises a first mounting ring, a stop ring disposed on the first mounting ring, and a second mounting ring disposed on the stop ring, the first mounting ring, the stop ring, and the second mounting ring being coaxial, and an outer diameter of the first mounting ring, an outer diameter of the stop ring, and an outer diameter of the second mounting ring decreasing in order;

the first mounting ring is fixedly connected with the end face of the driven wheel;

the magnetic ring is of a circular ring structure, and the magnetic ring is sleeved on the second mounting ring.

22. The camera of claim 21, wherein the end surface of the driven wheel facing the magnetic encoder is provided with at least one second mounting hole along the circumferential direction thereof, the first mounting ring is provided with at least one third mounting hole along the circumferential direction thereof, and the third mounting holes correspond to the second mounting holes one to one;

the camera further comprises at least one second fastening piece, and the second fastening piece penetrates through the second mounting hole and the corresponding third mounting hole so as to fix the first mounting ring on the end face, facing the magnetic encoder, of the driven wheel.

23. The camera of claim 22, further comprising a second circuit board on which the magnetic encoder and the controller are integrated;

the second circuit board is provided with at least one second fixing hole, the fixing frame is provided with at least one second fixing column, the second fixing columns correspond to the second fixing holes in a one-to-one mode, and the second fixing columns penetrate through the second fixing holes so that the second circuit board can be fixed on the fixing frame.

24. The camera of any of claims 14, 21 to 23, wherein the magnetic encoder is disposed outside the magnetic loop.

25. The camera of claim 24, wherein the magnetic loop is a multi-pair polar magnetic loop.

26. The camera of any one of claims 14, 21-23, wherein said controller invokes an executable program in said memory to compare said actual rotation angle with said target rotation angle, comprising:

the controller performs linear correction on the received actual rotation angle to obtain a corrected actual rotation angle;

and the controller calls an executable program in the memory to compare the corrected actual rotating angle with the target rotating angle, and calls the executable program in the memory to regulate the rotating angle of the motor in a feedback manner according to a comparison result.