Lifting camera lifting position detection system and method based on double-shaft Hall sensor

Abstract

The invention belongs to the technical field of lifting camera detection, and particularly relates to a lifting camera lifting position detection system and method based on a double-shaft Hall sensor, a camera module performs lifting motion through a lifting module, and a magnet assembly is located on a sliding block connected with the camera module. The double-shaft Hall sensor is located at the side edge position of the lifting stroke center of the lifting module, the double-shaft Hall sensor is used for detecting X-axis and Y-axis magnetic flux signals generated by the lifting motion of the magnet assembly on the lifting module, and the double-shaft Hall sensor is connected with the signal processing module; the signal processing module is used for receiving X-axis and Y-axis magnetic flux signals measured by the double-axis Hall sensor and calling a preset position algorithm to calculate the current position of the camera module. According to the invention, the problems of weak anti-interference capability and low detection dimension of the lifting position detection technology of the lifting camera in the prior art can be solved.

Description

Technical Field

[0001] The present invention belongs to the technical field of lifting camera detection, and particularly relates to a lifting position detection system and method for a lifting camera based on a biaxial Hall sensor. Background Art

[0002] With the continuous progress of camera technology, lifting cameras are widely used in many fields such as smart phones, monitoring devices, and drones; in these application scenarios, to achieve precise control of the lifting camera, its position detection technology is crucial; currently, the commonly used position detection solutions mostly adopt single-axis Hall sensors. Generally, the Hall sensor is placed at the upper and lower ends of the lifting module, and its characteristic of detecting magnetic field changes is used to judge the position of the camera.

[0003] When the single-axis Hall sensor is working, it has unique characteristics; when it is at one end of the stroke, the distance from the magnet determines the magnitude of the detected magnetic flux. The magnet moves with the lifting and lowering of the camera module, and the lifting and lowering position of the camera module has an exponential function relationship with the Hall detection data; as the camera module moves farther and farther away from the Hall sensor, the change in the Hall detection data becomes increasingly small until it almost approaches zero. During this process, the anti-interference ability of the sensor gradually weakens and is extremely vulnerable to external magnetic fields, which may in turn cause abnormal functions.

[0004] The traditional single-axis Hall sensor detection solution has many drawbacks. First, the problem of external magnetic field interference is serious. External magnetic fields generated by devices such as mobile phone speakers and wireless charging devices will affect the detection accuracy of the Hall sensor, resulting in deviation in position detection. This not only affects the accurate lifting and lowering of the camera but also reduces the stability of the device. Second, the detection dimension is single. The single-axis Hall sensor can only detect the change in magnetic flux in a single direction and is difficult to effectively cope with a complex magnetic field environment. Summary of the Invention

[0005] The technical problem to be solved by the present invention is to provide a lifting position detection system and method for a lifting camera based on a biaxial Hall sensor to solve the problems of weak anti-interference ability and low detection dimension existing in the lifting position detection technology of the existing lifting camera.

[0006] The basic solution provided by the present invention: a lifting position detection system for a lifting camera based on a biaxial Hall sensor, comprising a lifting camera module, a magnet assembly, a biaxial Hall sensor, and a signal processing module. The lifting camera module includes a camera module and a lifting module. The lifting module includes a slider and a lifting component. The slider is mounted on the lifting component. The camera module is fixedly connected to the slider and moves up and down on the lifting component. The magnet assembly is located on the slider connected to the camera module. The biaxial Hall sensor is located at a side position at the center of the lifting stroke of the lifting component. The biaxial Hall sensor is used to detect the magnetic flux signals of the X-axis and Y-axis generated by the up and down movement of the magnet assembly on the lifting component. The biaxial Hall sensor is connected to the signal processing module. The signal processing module is used to receive the magnetic flux signals of the X-axis and Y-axis measured by the biaxial Hall sensor and call a preset position algorithm to calculate the current position of the camera module. The specific position algorithm preset in the signal processing module is as follows: Calculate the angle of the magnetic field in the XY plane according to the magnetic fluxes of the X-axis and Y-axis of the biaxial Hall sensor, and obtain the lifting position of the camera module according to the mapping relationship between the lifting position and the angle.

[0007] Furthermore, the signal processing module includes a data receiving unit, a data processing unit, a data calibration unit, and a lifting position mapping unit, where: The data receiving unit is used to receive the magnetic flux signals of the X-axis and Y-axis transmitted by the biaxial Hall sensor; The data processing unit is used to calculate the angle of the magnetic field of the magnet assembly in the XY plane according to the magnetic fluxes of the X-axis and Y-axis received by the biaxial Hall sensor; The data calibration unit is used to receive the magnetic flux signals of the X-axis and Y-axis collected by the biaxial Hall sensor once every preset time during the process of the camera module rising from the bottom to the top driven by the lifting module, and call the data processing unit to calculate and generate the angle. Finally, a corresponding lifting position-angle mapping relationship is generated according to different time periods from the bottom to the top position; The lifting position mapping unit is used to generate the lifting position result of the camera module according to the lifting position-angle mapping relationship and the angle obtained by the real-time processing of the data processing unit.

[0008] Furthermore, the specific method for calculating the angle of the magnetic field of the magnet assembly in the XY plane according to the magnetic fluxes of the X-axis and Y-axis received by the biaxial Hall sensor in the data processing unit is as follows: When the magnet assembly moves up and down on the lifting module, the magnetic fluxes of the X-axis and Y-axis detected by the biaxial Hall sensor are respectively and ; Receive the magnetic fluxes of the X-axis and Y-axis and , the included angle is calculated, and the expression is:

[0009] wherein, 、 are adjusted in real time according to the measuring ranges of the X-axis and Y-axis by the biaxial Hall sensor and the relationships between the installation position, distance, and direction of the magnet and the Hall sensor.

[0010] Furthermore, the data calibration unit is further configured to construct a lifting position calculation mathematical model based on the lifting position-included angle mapping relationship, and calculate the lifting position of the camera module according to the lifting position calculation mathematical model.

[0011] Furthermore, the lifting assembly includes a motor assembly and a guide rail. The motor assembly includes a motor and a lifting drive rod, and the lifting drive rod is connected to the motor drive shaft; The slider is installed on the guide rail, the camera module and the magnet assembly are installed on the slider, the guide rail is arranged parallel to the lifting drive rod, and the slider is also connected to the lifting drive rod and moves up and down on the lifting drive rod.

[0012] Furthermore, the magnet assembly uses a small neodymium iron boron magnet, and the small neodymium iron boron magnet is fixed on the side of the slider close to the installation side of the biaxial Hall sensor.

[0013] The lifting position detection method of the lifting camera based on the biaxial Hall sensor is applied to the above-mentioned lifting camera lifting position detection system based on the biaxial Hall sensor, and includes: S1: Construct a lifting camera lifting position detection device based on the lifting camera module, the magnet assembly, the biaxial Hall sensor, and the signal processing module; S2: Measure the magnetic flux signals of the X-axis and Y-axis by the biaxial Hall sensor according to the up-and-down movement of the magnet assembly on the lifting module, and transmit them to the signal processing module; S3: The signal processing module calculates the included angle of the magnetic field in the XY plane according to the magnetic fluxes of the X-axis and Y-axis of the biaxial Hall sensor, and obtains the lifting position of the camera module according to the mapping relationship between the lifting position and the included angle.

[0014] The principle and advantages of the present invention are as follows: In this application, the lifting camera module consists of a camera module and a lifting module. The lifting module includes a slider and a lifting component. The slider is placed in the lifting component, the magnet component is arranged on the slider, and the biaxial Hall sensor is located on the side of the center of the lifting stroke of the lifting component. When the camera module moves up and down on the lifting component, the magnet component moves accordingly. The biaxial Hall sensor measures the magnetic flux signals of the X-axis and Y-axis according to its movement and transmits this signal to the signal processing module connected thereto. The data receiving unit in the signal processing module first receives the magnetic flux signal, and the data processing unit calculates the angle between the magnetic fields of the magnet component in the XY plane based on this signal. The data calibration unit receives the signals collected by the biaxial Hall sensor at preset times during the process of the camera module rising from the bottom to the top, calculates the angle through the data processing unit, and then generates the mapping relationship between the lifting position and the angle. Finally, the control unit obtains the lifting position result of the camera module according to this mapping relationship and the angle obtained by real-time processing. Its technical effect is remarkable. Compared with the traditional single-axis Hall sensor solution, the biaxial Hall sensor can detect the magnetic flux in two dimensions, effectively improving the detection dimension and enhancing the adaptability to complex magnetic field environments; through the unique position algorithm and the collaborative work of each unit of the signal processing module, the influence of external magnetic field interference on the position detection accuracy is reduced, the detection accuracy is improved, the lifting position of the camera module can be detected more accurately, ensuring the stable operation of the lifting camera, and meeting the requirements of strong anti-interference ability and multiple detection dimensions without increasing too much cost. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] Figure 1 is a schematic structural diagram of the detection system according to an embodiment of the present invention; Figure 2 is a functional block diagram of the signal processing module in an embodiment of the present invention; Figure 3 is the X-axis and Y-axis data of the entire stroke of the camera module detected by the biaxial Hall sensor in an embodiment of the present invention; Figure 4 is Figure 3 the detected diagram of the angle data obtained by calculating the data in; Figure 5 is a flowchart of the method of the present invention. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0016] The following is a further detailed description through specific embodiments: The reference signs in the accompanying drawings of the specification include: camera module 1, motor 2, lifting drive rod 3, slider 4, guide rail 5, magnet component 6, biaxial Hall sensor 7.

[0017] The embodiment is basically as shown in the attached Figure 1As shown: The lifting camera lifting position detection system based on the biaxial Hall sensor 7 includes a lifting camera module, a magnet assembly 6, a biaxial Hall sensor 7, and a signal processing module. Among them, the lifting camera module includes a camera module 1 and a lifting module. For the camera module 1, it is selected according to the actual application scenario and shooting requirements. In the lifting module, there are a slider and a lifting component. The lifting component includes a motor component and a guide rail. The motor component includes a motor 2 and a lifting drive rod 3. The motor 2 uses a stepper motor, which is paired with a lifting drive rod 3 with high precision and good strength. The lifting drive rod 3 uses a metal screw rod, which is connected to the drive shaft of the motor 2 to efficiently convert the rotational motion of the motor 2 into a linear lifting motion. The slider 4 is installed on the guide rail 5, and the slider 4 is also connected to the lifting drive rod 3. The motor 2 drives the lifting drive rod 3 to rotate, and the rotation of the lifting drive rod 3 drives the slider 4 to make a lifting motion. The guide rail 5 is selected as a smooth stainless steel guide rail 5 to prevent deviation in the direction during movement.

[0018] The slider 4 has good load-bearing capacity, and the camera module 1 and the magnet assembly 6 are installed on it. Specifically, the camera module 1 is installed on the top of the slider 4, and the magnet assembly 6 is installed on one side above the slider 4. The biaxial Hall sensor 7 is located on the side of the center of the lifting stroke of the lifting module. In this embodiment, a Hall effect is generated between the biaxial Hall sensor 7 and the magnet assembly 6. Specifically, the Hall effect means that when an electric current flows through a conductor, if a magnetic field perpendicular to the direction of the electric current is applied, an electric potential difference perpendicular to both the direction of the electric current and the direction of the magnetic field will be generated in the conductor, and the intensity and direction of the magnetic field can be sensed by detecting this electric potential difference. Therefore, through the interaction between the magnet assembly 6 installed on the slider 4 and the biaxial Hall sensor 7, when the magnet assembly 6 moves with the lifting of the camera module 1, the biaxial Hall sensor 7 will detect the change in the magnetic field. Since the generated magnetic field is in a shape similar to a semi-circular curve, and the change in the magnetic field involves not only the change in the magnetic field intensity but also the change in the magnetic field direction, the biaxial Hall sensor 7 can simultaneously sense the change in the magnetic flux of the X-axis and the Y-axis. At the same time, the biaxial Hall sensor 7 is connected to the signal processing module and can transmit the generated magnetic flux signal to the signal processing module.

[0019] The magnet assembly 6 uses a small neodymium iron boron magnet. Due to its characteristics of high magnetic energy product and high coercivity, it can generate a stable and strong magnetic field, which is convenient for the biaxial Hall sensor 7 to detect. The magnet assembly 6 is installed on the side of the slider 4 close to the biaxial Hall sensor 7. The direction of the magnetic field it generates is perpendicular to the X-axis detection direction of the biaxial Hall sensor 7 and is consistent with the Y-axis detection direction, providing a detectable magnetic flux signal for the biaxial Hall sensor 7 and playing a key role as a signal source carrier in the entire system, establishing a physical connection between the lifting camera module and the biaxial Hall sensor 7.

[0020] The dual-axis Hall sensor 7 selects the MLX90393 model. With the advantages of high precision, high sensitivity, low noise, etc., it can accurately measure the magnetic flux signal of the magnet assembly 6. Its operating voltage range and interface type need to match other circuits in the system to ensure stable operation. The dual-axis Hall sensor 7 is installed on the side position of the center of the lifting stroke of the lifting module, firmly fixed and the detection surface is opposite to the magnetic field direction of the magnet assembly 6, converting the detected magnetic flux signal into an electrical signal and outputting it to the signal processing module, which is the key bridge connecting physical quantity detection and signal processing.

[0021] As Figure 2 shown, the signal processing module receives the magnetic flux signals of the X-axis and Y-axis measured by the dual-axis Hall sensor 7, and calls the preset position algorithm to calculate the current position of the camera module 1; specifically, the preset position algorithm is: Calculate the angle of the magnetic field in the XY plane according to the magnetic fluxes of the X-axis and Y-axis of the dual-axis Hall sensor 7, and obtain the lifting position of the camera module 1 according to the mapping relationship between the lifting position and the angle.

[0022] To better illustrate the functions executed in the signal processing module of this application, the signal processing module includes a data reception unit, a data processing unit, a data calibration unit, and a lifting position mapping unit, where: The data reception unit is used to receive the magnetic flux signals of the X-axis and Y-axis transmitted by the dual-axis Hall sensor 7; based on the received magnetic flux signals of the X-axis and Y-axis transmitted by the dual-axis Hall sensor 7, the data processing unit calculates the angle of the magnetic field of the magnet assembly 6 in the XY plane, and the calculation process is: First, when the magnet assembly 6 makes a lifting movement on the lifting module, the magnetic fluxes detected by the dual-axis Hall sensor 7 on the X-axis and Y-axis are respectively and ; then receive the magnetic fluxes and of the X-axis and Y-axis, and perform the calculation of the angle. The expression is:

[0023] where 、 are adjusted in real time according to the range of the X-axis and Y-axis detected by the dual-axis Hall sensor 7 and the relationships such as the installation position, distance, and direction between the magnet and the Hall sensor.

[0024] For example, if the ranges of the X-axis and Y-axis detected by the dual-axis Hall sensor 7 are both set to 16 bits, representing 25 mT, according to the magnetic pole direction generated by the magnet and the distance between the magnet and the Hall sensor in actual experiments, 、 can be taken as 0.15 and 0.15 respectively; then the angle calculation formula is:

[0025] The data calibration unit is used to receive the magnetic flux signals of the X-axis and Y-axis collected by the biaxial Hall sensor 7 once every preset time during the process of the camera module 1 rising from the bottom to the top under the drive of the lifting module, and call the data processing unit to calculate and generate the included angle. Finally, a corresponding lifting position-included angle mapping relationship is generated according to different time periods from the bottom to the top position; in this embodiment, the data calibration unit only needs to be calibrated before use, and the generated lifting position and included angle mapping relationship table is stored in the flash memory. During the normal lifting use afterwards, only the relationship table needs to be taken out for use, and there is no need to calibrate again.

[0026] In this embodiment, under the drive of the motor 2, the camera module 1 rises from the bottommost to the topmost at a fixed speed. During the rising process, the magnetic flux of the XY-axis is detected once every preset fixed time, and through the processing logic of the data processing unit, it is converted into an included angle. Finally, an included angle mapping table of different time periods from the bottommost to the topmost position is obtained. During this lifting process, the detection time frequency is fixed, the lifting is uniform, and the time and position relationship is proportional. Therefore, through the mapping table of the lifting time and the included angle, the mapping table of the lifting position and the included angle can be converted, as Figure 3 shown in Table 1 below. Table 1 shows a partial mapping relationship table.

[0027] Table 1

[0028] As Figure 4 shown, finally, the lifting position mapping unit is used to generate the lifting position result of the camera module 1 according to the lifting position-included angle mapping relationship and the included angle obtained by the real-time processing of the data processing unit.

[0029] As Figure 5 shown, in another embodiment of this embodiment, there is also a method for detecting the lifting position of a lifting camera based on the biaxial Hall sensor 7, which is applied to the above-mentioned system for detecting the lifting position of a lifting camera based on the biaxial Hall sensor 7, and includes: S1: Construct a device for detecting the lifting position of a lifting camera based on the lifting camera module, the magnet assembly 6, the biaxial Hall sensor 7 and the signal processing module; S2: The biaxial Hall sensor 7 measures the magnetic flux signals of the X-axis and Y-axis according to the lifting movement of the magnet assembly 6 on the lifting module and transmits them to the signal processing module; S3: The signal processing module calculates the included angle of the magnetic field in the XY plane according to the magnetic flux of the X-axis and Y-axis of the biaxial Hall sensor 7, and obtains the lifting position of the camera module 1 according to the mapping relationship between the lifting position and the included angle.

[0030] Embodiment 2: The difference between Embodiment 2 and Embodiment 1 is that in Embodiment 2, in the data calibration unit, based on the mapping relationship between the lifting position and the angle, a mathematical model for calculating the lifting position is constructed, and the lifting position of the camera module 1 is calculated according to the mathematical model for calculating the lifting position. For example, the expression is as follows:

[0031] Wherein, is the angle calculated based on the magnetic fluxes of the X-axis and Y-axis; In this embodiment, the above expression is not unique and varies specifically according to the position and distance relationship between the magnet and the Hall sensor. In practice, according to the lifting stroke in Table 1 obtained during calibration and the angle mapping table, the specific function relationship model is obtained through function simulation.

[0032] To verify the effectiveness of the mathematical model in Embodiment 2, as shown in Table 2 below, the relevant verification data are as follows: Table 2

[0033] Therefore, according to the verification data in Table 2 above, the average error is 0.02 and the maximum error is 0.03, meeting the requirements. So it is proved that the mathematical model for calculating the lifting position in this embodiment is feasible.

[0034] The above are only the embodiments of the present invention. Specific structures and common knowledge such as characteristics well known in the art are not described in detail here. Those of ordinary skill in the art know all the common general technical knowledge in the technical field to which the invention belongs before the application date or the priority date, can learn all the existing technologies in this field, and have the ability to apply the conventional experimental means before this date. Those of ordinary skill in the art can, under the inspiration given in this application, combine their own abilities to improve and implement this solution. Some typical well-known structures or well-known methods should not be an obstacle for those of ordinary skill in the art to implement this application. It should be noted that for those skilled in the art, without departing from the structure of the present invention, several deformations and improvements can still be made, and these should also be regarded as the protection scope of the present invention, and these will not affect the implementation effect of the present invention and the practicality of the patent. The protection scope required by this application should be based on the content of its claims, and the specific implementation manners and the like recorded in the specification can be used to interpret the content of the claims.

Claims

1. A lifting camera lifting position detection system based on a biaxial Hall sensor, characterized in that: It includes a lifting camera module, a magnet assembly, a biaxial Hall sensor, and a signal processing module. The lifting camera module includes a camera module and a lifting module. The lifting module includes a slider and a lifting component. The slider is installed on the lifting component. The camera module is fixedly connected to the slider and moves up and down on the lifting component. The magnet assembly is located on the slider connected to the camera module. The biaxial Hall sensor is located at the side position of the center of the lifting stroke of the lifting component. The biaxial Hall sensor is used to detect the magnetic flux signals of the X-axis and Y-axis generated by the up-and-down movement of the magnet assembly on the lifting component. The biaxial Hall sensor is connected to the signal processing module; the signal processing module is used to receive the magnetic flux signals of the X-axis and Y-axis measured by the biaxial Hall sensor and call a preset position algorithm to calculate the current position of the camera module; The preset position algorithm in the signal processing module is specifically: Calculate the angle of the magnetic field in the XY plane according to the magnetic fluxes of the X-axis and Y-axis of the biaxial Hall sensor, and obtain the lifting position of the camera module according to the mapping relationship between the lifting position and the angle.

2. The lifting camera lifting position detection system based on a biaxial Hall sensor according to claim 1, characterized in that: The signal processing module includes a data receiving unit, a data processing unit, a data calibration unit, and a lifting position mapping unit, where: The data receiving unit is used to receive the magnetic flux signals of the X-axis and Y-axis transmitted by the biaxial Hall sensor; The data processing unit is used to calculate the angle of the magnetic field of the magnet assembly in the XY plane according to the magnetic fluxes of the X-axis and Y-axis received by the biaxial Hall sensor; The data calibration unit is used to receive the magnetic flux signals of the X-axis and Y-axis collected by the biaxial Hall sensor once according to a preset time during the process of the camera module rising from the bottom to the top driven by the lifting module, and call the data processing unit to calculate and generate the angle, and finally generate a corresponding lifting position - angle mapping relationship according to different time periods from the bottom to the top position; The lifting position mapping unit is used to generate the lifting position result of the camera module according to the lifting position - angle mapping relationship and the angle obtained by the real-time processing of the data processing unit.

3. The lifting camera lifting position detection system based on a biaxial Hall sensor according to claim 2, wherein: The specific method for the data processing unit to calculate the angle of the magnetic field of the magnet assembly in the XY plane according to the magnetic fluxes of the X-axis and Y-axis received by the biaxial Hall sensor is: When the magnet assembly moves up and down on the lifting module, the biaxial Hall sensor detects that the magnetic fluxes of the X-axis and Y-axis are respectively and ; Receive the magnetic fluxes of the X-axis and Y-axis and , perform the calculation of the included angle, and the expression is: Among them, and It is adjusted in real time according to the ranges of the X-axis and Y-axis detected by the biaxial Hall sensor and the relationships between the installation position, distance, and direction of the magnet and the Hall sensor.

4. The lifting camera lifting position detection system based on a biaxial Hall sensor according to claim 2, wherein: The data calibration unit is also used to construct a mathematical model for calculating the lifting position based on the lifting position - angle mapping relationship, and calculate the lifting position of the camera module according to the mathematical model for calculating the lifting position.

5. The lifting camera lifting position detection system based on a biaxial Hall sensor according to claim 4, characterized in that: The lifting component includes a motor assembly and a guide rail. The motor assembly includes a motor and a lifting drive rod. The lifting drive rod is connected to the motor drive shaft; The slider is installed on the guide rail. The camera module and the magnet assembly are installed on the slider. The guide rail is arranged relatively parallel to the lifting drive rod. The slider is also connected to the lifting drive rod and moves up and down on the lifting drive rod.

6. The lifting camera lifting position detection system based on a biaxial Hall sensor according to claim 5, wherein: The magnet assembly uses a small neodymium iron boron magnet, and the small neodymium iron boron magnet is fixed on the side of the slider close to the installation side of the biaxial Hall sensor.

7. A method for detecting the lifting position of a lifting camera based on a biaxial Hall sensor, which is applied to the lifting camera lifting position detection system based on a biaxial Hall sensor according to any one of the above claims 1-6, characterized in that: It includes: S1: Construct a lifting camera lifting position detection device based on the lifting camera module, the magnet assembly, the biaxial Hall sensor, and the signal processing module; S2: Measure the magnetic flux signals of the X-axis and Y-axis according to the lifting movement of the magnet assembly on the lifting module by means of a biaxial Hall sensor, and transmit them to the signal processing module; S3: The signal processing module calculates the angle of the magnetic field in the XY plane based on the magnetic fluxes of the X-axis and Y-axis of the biaxial Hall sensor, and obtains the lifting position of the camera module according to the mapping relationship between the lifting position and the angle.

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