A tilt measuring device and method based on two-dimensional PSD sensor

Abstract

The application provides a tilt measuring device and method based on a two-dimensional PSD sensor. The device comprises a laser pendulum unit arranged in a mounting cylinder and connected to the top wall of the mounting cylinder through a cycloid, a position measuring unit based on a PSD sensor, and a data acquisition and processing unit arranged outside the mounting cylinder and connected to the position measuring unit. When measuring, the bottom of the mounting cylinder is attached to the surface to be measured. The laser pendulum unit is used to emit a vertical downward laser beam and form a laser spot on the photosensitive surface of the PSD. The position measuring unit is used to output two voltage signals whose amplitudes are proportional to the two-dimensional position coordinates of the laser spot deviating from the center of the photosensitive surface of the PSD. The data acquisition and processing unit is used to convert the voltage signals into digital signals, and calculate the tilt angle of the surface to be measured by solving the two-dimensional position coordinates of the laser spot. The application can greatly improve the measurement accuracy of the tilt angle by using a two-dimensional PSD sensor and a laser pendulum unit.

Description

Technical Field

[0001] This invention belongs to the field of tilt measurement technology, specifically relating to a tilt measurement device and method based on a two-dimensional PSD (Position Sensitive Detector) sensor. Background Technology

[0002] In fields such as industrial automation, construction surveying, and geological exploration, accurate angle measurement is crucial for ensuring operational safety and accuracy. Traditional inclinometers primarily rely on mechanical structures or inertial sensors such as accelerometers or gyroscopes to measure tilt angles by detecting changes in the direction of gravity. While these technologies offer relatively convenient angle measurement, they have limitations in accuracy, response speed, and interference resistance. In general, they suffer from the following drawbacks: Low measurement accuracy: Inertial sensors have low accuracy when measuring small angle changes, especially under the influence of environmental noise or vibration; Cumulative error: Over long-term use, inertial sensors accumulate errors, leading to inaccurate measurement results; Unstable dynamic measurement: Accelerometers are affected by motion acceleration during dynamic measurements, making it difficult to obtain accurate tilt angles; Weak interference resistance: Existing technologies are susceptible to interference in high-noise or high-vibration environments, resulting in low reliability. Summary of the Invention

[0003] To address the aforementioned problems in the prior art, this invention provides a tilt measurement device and method based on a two-dimensional PSD sensor.

[0004] To achieve the above objectives, the present invention adopts the following technical solution.

[0005] In a first aspect, the present invention provides a tilt measurement device based on a two-dimensional PSD sensor, comprising: a laser pendulum unit disposed inside a mounting cylinder and connected to the top wall of the mounting cylinder via a cycloid; a position measurement unit based on the PSD sensor located below the laser pendulum unit and fixed on a substrate at the bottom of the mounting cylinder; and a data acquisition and processing unit disposed outside the mounting cylinder and connected to the position measurement unit. During measurement, the bottom of the mounting cylinder is in contact with the surface to be measured. The laser pendulum unit is used to emit a vertically downward laser beam and form a laser spot on the PSD photosensitive surface. The position measurement unit is used to output two voltage signals with amplitudes proportional to the two-dimensional position coordinates of the laser spot deviating from the center of the PSD photosensitive surface. The data acquisition and processing unit is used to convert the voltage signals into digital signals and calculate the tilt angle of the surface to be measured by solving the two-dimensional position coordinates of the laser spot.

[0006] Furthermore, the mounting cylinder is a cylindrical double-layer vacuum cylinder.

[0007] Furthermore, the laser pendulum unit includes: a first controller mounted on a circuit board and a laser emitter connected thereto, a first wireless communication module, and a power management module. The first wireless communication module is used to realize wireless communication between the laser pendulum unit and the position measurement unit, and the power management module is used to provide operating voltage for the laser pendulum unit and can realize wireless charging of the battery.

[0008] Furthermore, the position measurement unit includes: a second controller, a PSD sensor and a second wireless communication module connected to the second controller, and a signal processing module connected to the PSD sensor; the second wireless communication module is used to realize wireless communication between the position measurement unit and the laser pendulum unit by cooperating with the first wireless communication module under the action of the second controller; the signal processing module is used to transform and amplify the current signal output by the PSD sensor that is related to the two-dimensional position coordinates of the laser spot, and then output two voltage signals with amplitudes proportional to the two-dimensional position coordinates of the laser spot.

[0009] Furthermore, the signal processing module includes: four current-to-voltage converters and amplifiers connected to the four electrodes of the PSD sensor respectively; four low-pass filters connected to the four current-to-voltage converters and amplifiers respectively; and two arithmetic units composed of adders, subtractors, and dividers connected to the four low-pass filters; wherein, the four electrodes of the PSD sensor respectively output current signals I. x+ I x- and I y+ I y- The four low-pass filters output voltage signals U respectively. x+ =kI x+ U x- =kI x- and U y+ =kI y+ U y- =kI y- k is the gain coefficient; the outputs of the two arithmetic units are as follows:

[0010] (1)

[0011] (2)

[0012] In the formula, U x U y These are two voltage signals that are proportional to the two-dimensional position coordinates of the laser spot.

[0013] Furthermore, the data acquisition and processing unit includes an analog-to-digital converter, a controller, a communication module connected to the controller for communicating with a host computer, and a power supply module.

[0014] Furthermore, the calculation method for the tilt angle of the surface to be measured includes:

[0015] Establish a Cartesian coordinate system xoy with the center of the PSD photosensitive surface as the origin o, and the directions of the lines connecting the two pairs of electrodes of the PSD as the x-axis and y-axis, respectively;

[0016] Obtain the position coordinates (x, y) of the laser spot in the xoy coordinate system at the current time t. t ,y t );

[0017] The inclination angle of the surface to be measured is calculated using the following formula:

[0018] (3)

[0019] In the formula, θ is the tilt angle of the surface to be measured, and L is the distance between the upper end of the cycloid and the center of the PSD photosensitive surface.

[0020] Furthermore, the tilt angle θ of the surface under test has the following tilt components in the x-axis and y-axis directions:

[0021] (4)

[0022] (5)

[0023] In the formula, θ x θ y These are the tilt components of θ in the x-axis and y-axis directions, respectively.

[0024] Furthermore, methods for calibrating the tilt angle of the surface to be measured include:

[0025] Adjust the bubble level at the top of the mounting cylinder so that the cycloid is in the direction of the axis of the mounting cylinder, and obtain the position coordinates (x0, y0) of the laser spot;

[0026] coordinates (x) t ,y t ) calibrated to (x t -x0,y t -y0);

[0027] θ is calibrated using the following formula:

[0028] (6)

[0029] In the formula, θ' is the calibrated value;

[0030] Apply the following formulas to θ respectively x θ y Perform calibration:

[0031] (7)

[0032] (8)

[0033] In the formula, θ' x ,θ' y θ x θ y The calibrated value.

[0034] Secondly, the present invention provides a method for tilt measurement using the aforementioned device, comprising the following steps:

[0035] After the device is placed on the surface to be measured, the laser pendulum unit emits a vertically downward laser beam and forms a laser spot on the photosensitive surface of the PSD sensor;

[0036] The position measurement unit outputs two voltage signals with amplitudes proportional to the two-dimensional position coordinates of the laser spot.

[0037] The data acquisition and processing unit converts the voltage signal into a digital signal and calculates the tilt angle of the surface under test by solving the position coordinates of the laser spot.

[0038] Compared with the prior art, the present invention has the following beneficial effects.

[0039] This invention utilizes a mounting cylinder with its bottom attached to the surface to be measured. Inside the cylinder, a laser pendulum unit is connected to the top wall via a cycloidal line. Below the laser pendulum unit, a position measurement unit based on a PSD sensor is fixed to a substrate at the bottom of the mounting cylinder. Outside the mounting cylinder, a data acquisition and processing unit is connected to the position measurement unit. The laser pendulum unit emits a vertically downward laser beam, forming a laser spot on the PSD photosensitive surface. The position measurement unit outputs two voltage signals with amplitudes proportional to the two-dimensional position coordinates of the laser spot's deviation from the center of the PSD photosensitive surface. The data acquisition and processing unit converts these voltage signals into digital signals. By solving for the two-dimensional position coordinates of the laser spot, the tilt angle of the surface to be measured is calculated, enabling automatic measurement of the tilt angle. This invention, by employing a two-dimensional PSD sensor and a laser pendulum unit, significantly improves the accuracy of tilt angle measurement. Attached Figure Description

[0040] Figure 1 This is a block diagram of a tilt measurement device based on a two-dimensional PSD sensor according to an embodiment of the present invention.

[0041] Figure 2 This is a schematic diagram showing the shape and cross-section of the mounting cylinder.

[0042] Figure 3 This is a schematic diagram of a two-dimensional PSD photosensitive surface.

[0043] Figure 4 This is a schematic diagram of the signal processing module.

[0044] Figure 5 A schematic diagram of the geometric relationship for calculating the tilt angle.

[0045] Figure 6 This is a flowchart illustrating a method for tilt measurement using the aforementioned device, according to an embodiment of the present invention.

[0046] Figure 1 , 2 The numbers in the middle represent: 1-Laser pendulum unit, 2-Position measurement unit, 3-Data acquisition and processing unit. Detailed Implementation

[0047] To make the objectives, technical solutions, and advantages of this invention clearer and more understandable, the invention will be further described below in conjunction with the accompanying drawings and specific embodiments. Obviously, the described embodiments are merely some embodiments of this invention, and not all embodiments. Based on the embodiments of this invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this invention.

[0048] Figure 1 This is a block diagram of a tilt measurement device based on a two-dimensional PSD sensor according to an embodiment of the present invention. It includes: a laser pendulum unit connected to the top wall of the mounting cylinder via a cycloid inside the mounting cylinder; a position measurement unit based on the PSD sensor located below the laser pendulum unit and fixed to the bottom substrate of the mounting cylinder; and a data acquisition and processing unit located outside the mounting cylinder and connected to the position measurement unit. During measurement, the bottom of the mounting cylinder is in contact with the surface to be measured. The laser pendulum unit emits a vertically downward laser beam and forms a laser spot on the PSD photosensitive surface. The position measurement unit outputs two voltage signals with amplitudes proportional to the two-dimensional position coordinates of the laser spot's deviation from the center of the PSD photosensitive surface. The data acquisition and processing unit converts the voltage signals into digital signals and calculates the tilt angle of the surface to be measured by solving for the two-dimensional position coordinates of the laser spot.

[0049] In this embodiment, the device mainly consists of a laser pendulum unit, a position measurement unit, and a data acquisition and processing unit. The laser pendulum unit and the position measurement unit are disposed inside the mounting cylinder, while the data acquisition and processing unit is disposed outside the mounting cylinder, as shown below. Figure 2 As shown. Each unit will be explained separately below.

[0050] The laser pendulum unit is primarily used to emit a vertically downward laser beam. As the name suggests, the mechanical structure of the laser pendulum unit is a simple pendulum. The hardware module of the laser pendulum unit is fixed on a circuit board and connected to the lower end of a pendulum line fixed at the center of the top wall of the mounting cylinder. The pendulum line and the circuit board together form a simple pendulum that can swing freely around the center of the top wall of the mounting cylinder. When performing tilt measurements, the mounting cylinder is placed on the surface to be measured with its bottom in contact with the surface. When the pendulum is at rest, regardless of whether the surface to be measured is tilted or the size of the tilt angle (within the measurement range), the pendulum line always remains vertical under the influence of gravity. Therefore, the laser head of the laser pendulum unit can emit a vertically downward laser beam, which strikes the PSD photosensitive surface of the position measurement unit located below it, forming a laser spot. The position of the laser spot varies depending on the tilt angle of the surface to be measured; therefore, the tilt angle of the surface to be measured can be calculated based on the position of the laser spot.

[0051] The position measurement unit is mainly used to measure the two-dimensional position coordinates of the laser spot. The position measurement unit primarily consists of a two-dimensional PSD sensor. Based on the photoelectric effect, the PSD sensor converts the laser spot into an electrical signal, and a photocurrent proportional to the position of the laser spot is obtained at the two output electrodes. The PSD sensor is a novel position detector developed in recent years; it is a photoelectric device sensitive to the position of the incident light spot on its photosensitive surface, and its output signal is related to the position of the laser spot on the photosensitive surface. A schematic diagram of the photosensitive surface of the two-dimensional PSD sensor is shown below. Figure 3 As shown, there are 4 output currents I. x+ I x- and I y+ I y- The electrode, the laser spot in Figure 3 The relationship between the coordinates (x, y) in the coordinate system shown (origin at the center of the photosensitive surface) and the four output currents is as follows:

[0052]

[0053]

[0054] In the formula, L0 is half the length or width of the photosensitive surface. According to the above formula, I x+ -I x- The larger x is, the larger I is. y+ -I y- The larger y is, the larger it is; when I x- =I x+ Or I y- =I y+ When x=0 or y=0; when I x- =0 or I y- When x = 0, x = L0 or y = L0.

[0055] The data acquisition and processing unit is mainly used to calculate the tilt angle of the surface under test. On one hand, it converts the voltage signal output by the position measurement unit into a digital signal; on the other hand, it calculates the tilt angle of the surface under test based on the two-dimensional position coordinates of the laser spot. The tilt angle of the surface under test is the angle between the surface under test and the horizontal plane, or it can be expressed as the angle between the normal direction of the surface under test and the normal direction (vertical direction) of the horizontal plane. In this embodiment, since the main body of the device is a cylindrical mounting cylinder, the mounting cylinder is placed on the surface under test during tilt measurement. The axial direction of the mounting cylinder is the normal direction of the surface under test, and the pendulum direction of the laser pendulum unit in a stationary state is always vertically downward. Therefore, this embodiment measures the tilt angle by calculating the angle by which the axial direction of the mounting cylinder deviates from the vertical direction.

[0056] As an optional embodiment, the mounting cylinder is a cylindrical double-layer vacuum cylinder.

[0057] This embodiment provides a specific design for the mounting cylinder. The mounting cylinder in this embodiment is a cylindrical double-layered vacuum cylinder. Using a double-layered vacuum cylinder effectively isolates external air convection and environmental noise interference, ensuring the measurement stability of the device under various complex environments.

[0058] As an optional embodiment, the laser pendulum unit includes: a first controller mounted on a circuit board and a laser emitter connected thereto, a first wireless communication module and a power management module. The first wireless communication module is used to realize wireless communication between the laser pendulum unit and the position measurement unit, and the power management module is used to provide operating voltage for the laser pendulum unit and can realize wireless charging of the battery.

[0059] This embodiment provides a circuit module constituting a laser pendulum unit. The hardware circuit module of the laser pendulum unit in this embodiment includes a first controller and a laser emitter, a first wireless communication module, and a power management module connected to it, all mounted on the same circuit board. The laser emitter generates a laser beam under the control of the first controller. The first wireless communication module is used to achieve wireless communication with a position measurement unit under the control of the first controller, such as receiving a start measurement command sent by the position measurement unit. Upon receiving the command, the first controller outputs a control signal to activate the laser emitter. The power management module provides DC operating voltage to the other modules of the laser pendulum unit. For convenient charging, the power management module also includes a wireless charging circuit, enabling periodic wireless charging of the battery.

[0060] As an optional embodiment, the position measurement unit includes: a second controller, a PSD sensor and a second wireless communication module connected to the second controller, and a signal processing module connected to the PSD sensor; the second wireless communication module is used to realize wireless communication between the position measurement unit and the laser pendulum unit by cooperating with the first wireless communication module under the action of the second controller; the signal processing module is used to transform and amplify the current signal output by the PSD sensor that is related to the two-dimensional position coordinates of the laser spot, and output two voltage signals with amplitudes proportional to the two-dimensional position coordinates of the laser spot.

[0061] This embodiment provides the circuit module constituting the position measurement unit. The position measurement unit in this embodiment mainly consists of a PSD sensor, and also includes a signal processing module, a second controller, and a second wireless communication module. The input terminal of the signal processing module is connected to the output terminal of the PSD sensor. It performs current-to-voltage conversion and amplification on the current signal output by the PSD sensor, outputting two voltage signals with amplitudes proportional to the two-dimensional position coordinates of the laser spot. The second wireless communication module, under the action of the second controller, cooperates with the first wireless communication module to realize wireless communication between the position measurement unit and the laser pendulum unit, such as sending commands to the laser pendulum unit to start measurement.

[0062] As an optional embodiment, the signal processing module includes: four current-to-voltage converters and amplifiers respectively connected to the four electrodes of the PSD sensor; four low-pass filters respectively connected to the four current-to-voltage converters and amplifiers; and two arithmetic units composed of adders, subtractors, and dividers connected to the four low-pass filters; wherein, the four electrodes of the PSD sensor respectively output current signals I. x+ I x- and I y+ I y- The four low-pass filters output voltage signals U respectively. x+ =kI x+ U x- =kI x- and U y+ =kI y+ U y- =kI y- k is the gain coefficient; the outputs of the two arithmetic units are as follows:

[0063] (1)

[0064] (2)

[0065] In the formula, U x U y These are two voltage signals that are proportional to the two-dimensional position coordinates of the laser spot.

[0066] This embodiment provides a technical solution for a signal processing module. The signal processing module consists of four current-to-voltage converters and amplifiers, four low-pass filters, two adders, two subtractors, and two dividers. The connection relationships of each module are as follows: Figure 4 As shown. The PSD sensor outputs four relatively weak current signals I from its four electrodes. x+ I x- and I y+ I y- Each current signal is converted to voltage and then amplified to output a voltage signal of a certain amplitude. These signals are then filtered by a low-pass filter to remove low-frequency interference, resulting in four voltage signals U. x+ =kI x+ U x- =kI x- and U y+ =kI y+ U y- =kI y- U x+ and U x- U is obtained after addition, subtraction, and division operations. x U x Proportional to the lateral distance between the laser spot and the center of the photosensitive surface (i.e., the x-coordinate), as in equation (1); similarly, U y+ and U y- U is obtained after addition, subtraction, and division operations. y U y It is proportional to the longitudinal distance between the laser spot and the center of the photosensitive surface (i.e., the horizontal coordinate y), as shown in equation (2).

[0067] As an optional embodiment, the data acquisition and processing unit includes an analog-to-digital converter, a controller, a communication module connected to the controller for communicating with a host computer, and a power supply module.

[0068] This embodiment provides a technical solution for a data acquisition and processing unit. The data acquisition and processing unit in this embodiment mainly consists of an analog-to-digital converter (ADC), a controller, a communication module, and a power supply module. The ADC, under the control of the controller, converts the analog voltage signal output by the signal processing module into a digital signal that the controller can process. The communication module is used to realize data communication with the host computer, such as receiving instructions from the host computer and uploading data to the host computer. The controller coordinates the work of other modules and completes necessary data processing tasks, such as calculating the laser spot position coordinates and tilt angle. The power supply module provides operating voltage to other modules.

[0069] As an optional embodiment, the method for calculating the tilt angle of the surface to be measured includes:

[0070] Establish a Cartesian coordinate system xoy with the center of the PSD photosensitive surface as the origin o, and the directions of the lines connecting the two pairs of electrodes of the PSD as the x-axis and y-axis, respectively;

[0071] Obtain the position coordinates (x, y) of the laser spot in the xoy coordinate system at the current time t. t ,y t );

[0072] The inclination angle of the surface to be measured is calculated using the following formula:

[0073] (3)

[0074] In the formula, θ is the tilt angle of the surface to be measured, and L is the distance between the upper end of the cycloid and the center of the PSD photosensitive surface.

[0075] This embodiment provides a technical solution for calculating the tilt angle of the surface to be measured. The tilt angle of the surface to be measured is the angle between the surface to be measured and the horizontal plane, and this angle is also equal to the angle between the normal direction of the surface to be measured and the normal direction of the horizontal plane, i.e., the vertical direction. The normal direction of the surface to be measured is the direction of the axis of the mounting cylinder (e.g., Figure 5 In the ZO (cycloid), the cycloid is vertically downward when in equilibrium (e.g., Figure 5 (ZA in the equation), therefore the inclination angle of the surface to be measured is equal to the angle between the axis of the mounting cylinder and the direction of the cycloid in equilibrium (e.g., ZA in the equation). Figure 5 (∠OZA in the text). According to Figure 5 The geometric relationship shown is ∠OZA = arctan(OA / OZ). Since... , OZ=L, thus obtaining the tilt angle calculation formula shown in equation (3).

[0076] As an optional embodiment, the tilt angle θ of the surface to be measured has the following tilt angle components in the x-axis and y-axis directions:

[0077] (4)

[0078] (5)

[0079] In the formula, θ x θ y These are the tilt components of θ in the x-axis and y-axis directions, respectively.

[0080] This embodiment provides a technical solution for calculating the tilt angle θ in the x-axis and y-axis directions. Based on... Figure 5 The tilt component θ in the x-axis direction x Let ∠OZC be the tilt component θ along the y-axis. y Given ∠OZB, based on the characteristics of a right triangle, it is easy to obtain the formulas for calculating the tilt component shown in equations (4) and (5).

[0081] As an optional embodiment, the method for calibrating the tilt angle of the surface to be measured includes:

[0082] Adjust the bubble level at the top of the mounting cylinder so that the cycloid is in the direction of the axis of the mounting cylinder, and obtain the position coordinates (x0, y0) of the laser spot;

[0083] coordinates (x) t ,y t ) calibrated to (x t -x0,y t -y0);

[0084] θ is calibrated using the following formula:

[0085] (6)

[0086] In the formula, θ' is the calibrated value;

[0087] Apply the following formulas to θ respectively x θ y Perform calibration:

[0088] (7)

[0089] (8)

[0090] In the formula, θ' x ,θ' y θ x θ y The calibrated value.

[0091] This embodiment provides a technical solution for calibrating the tilt angle. The method for calculating the tilt angle given in previous embodiments assumes that when the surface to be measured is horizontal, the laser spot hits the center of the PSD photosensitive surface, and the measured coordinates of the laser spot are (0,0). However, in reality, due to installation errors and other reasons, the measured coordinates will deviate from (0,0), resulting in tilt angle measurement errors. To improve the accuracy of the device in measuring the tilt angle, the device needs to be calibrated before first use, i.e., the coordinates of the laser spot (x0,y0) when the surface to be measured is horizontal. Since it is difficult to find a perfectly horizontal surface, this embodiment uses a bubble level located at the top of the mounting cylinder to adjust the level, ensuring the cycloid is aligned with the axis of the mounting cylinder. With (x0,y0), the calibrated coordinates (x0,y0) can be obtained. t -x0,y t -y0); then calculate the calibrated tilt angle θ' according to equation (6), and calculate the two tilt angle components after calibration according to equations (7) and (8).

[0092] Figure 6This is a flowchart of a method for performing tilt measurement using the device according to an embodiment of the present invention. The method includes the following steps:

[0093] Step 101: After placing the device on the surface to be tested, the laser pendulum unit emits a vertically downward laser beam and forms a laser spot on the photosensitive surface of the PSD sensor.

[0094] Step 102: The position measurement unit outputs two voltage signals with amplitudes proportional to the two-dimensional position coordinates of the laser spot;

[0095] Step 103: The data acquisition and processing unit converts the voltage signal into a digital signal and calculates the tilt angle of the surface under test by solving the position coordinates of the laser spot.

[0096] The method in this embodiment is similar to... Figure 1 The implementation principle and technical effect of the device embodiment shown are similar to those of the other embodiments, and will not be repeated here.

[0097] The above description is merely a specific embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any variations or substitutions that can be easily conceived by those skilled in the art within the technical scope disclosed in the present invention should be included within the scope of protection of the present invention. Therefore, the scope of protection of the present invention should be determined by the scope of the claims.

Claims

1. A tilt measurement device based on a two-dimensional PSD sensor, characterized in that, The device includes: a laser pendulum unit installed inside the mounting cylinder and connected to the top wall of the mounting cylinder via a cycloid; a position measurement unit based on a PSD sensor located below the laser pendulum unit and fixed on the bottom substrate of the mounting cylinder; and a data acquisition and processing unit installed outside the mounting cylinder and connected to the position measurement unit. During measurement, the bottom of the mounting cylinder is in contact with the surface to be measured. The laser pendulum unit emits a vertically downward laser beam and forms a laser spot on the PSD photosensitive surface. The position measurement unit outputs two voltage signals with amplitudes proportional to the two-dimensional position coordinates of the laser spot deviating from the center of the PSD photosensitive surface. The data acquisition and processing unit converts the voltage signals into digital signals and calculates the tilt angle of the surface to be measured by solving the two-dimensional position coordinates of the laser spot.

2. The tilt measurement device based on a two-dimensional PSD sensor according to claim 1, characterized in that, The mounting cylinder is a cylindrical double-layer vacuum cylinder.

3. The tilt measurement device based on a two-dimensional PSD sensor according to claim 1, characterized in that, The laser pendulum unit includes: a first controller mounted on a circuit board and a laser emitter connected thereto, a first wireless communication module and a power management module. The first wireless communication module is used to realize wireless communication between the laser pendulum unit and the position measurement unit. The power management module is used to provide operating voltage to the laser pendulum unit and can realize wireless charging of the battery.

4. The tilt measurement device based on a two-dimensional PSD sensor according to claim 1, characterized in that, The position measurement unit includes: a second controller, a PSD sensor and a second wireless communication module connected to the second controller, and a signal processing module connected to the PSD sensor; the second wireless communication module is used to realize wireless communication between the position measurement unit and the laser pendulum unit by cooperating with the first wireless communication module under the action of the second controller; the signal processing module is used to transform and amplify the current signal output by the PSD sensor that is related to the two-dimensional position coordinates of the laser spot, and output two voltage signals with amplitudes proportional to the two-dimensional position coordinates of the laser spot.

5. The tilt measurement device based on a two-dimensional PSD sensor according to claim 4, characterized in that, The signal processing module includes: four current-to-voltage converters and amplifiers connected to the four electrodes of the PSD sensor, four low-pass filters connected to the four current-to-voltage converters and amplifiers, and two arithmetic units consisting of an adder, a subtractor, and a divider connected to the four low-pass filters; wherein, the four electrodes of the PSD sensor output current signals I. x+ I x- and I y+ I y- The four low-pass filters output voltage signals U respectively. x+ =kI x+ U x- =kI x- and U y+ =kI y+ U y- =kI y- k is the gain coefficient; the outputs of the two arithmetic units are as follows: （1） （2） In the formula, U x U y These are two voltage signals that are proportional to the two-dimensional position coordinates of the laser spot.

6. The tilt measurement device based on a two-dimensional PSD sensor according to claim 1, characterized in that, The data acquisition and processing unit includes an analog-to-digital converter, a controller, a communication module connected to the controller for communicating with a host computer, and a power supply module.

7. The tilt measurement device based on a two-dimensional PSD sensor according to claim 1, characterized in that, The methods for calculating the inclination angle of the surface to be measured include: Establish a Cartesian coordinate system xoy with the center of the PSD photosensitive surface as the origin o, and the directions of the lines connecting the two pairs of electrodes of the PSD as the x-axis and y-axis, respectively; Obtain the position coordinates (x, y) of the laser spot in the xoy coordinate system at the current time t. t ,y t ); The inclination angle of the surface to be measured is calculated using the following formula: （3） In the formula, θ is the tilt angle of the surface to be measured, and L is the distance between the upper end of the cycloid and the center of the PSD photosensitive surface.

8. The tilt measurement device based on a two-dimensional PSD sensor according to claim 7, characterized in that, The tilt angle θ of the surface under test has the following tilt components in the x-axis and y-axis directions: (4) (5) In the formula, θ x θ y These are the tilt components of θ in the x-axis and y-axis directions, respectively.

9. The tilt measurement device based on a two-dimensional PSD sensor according to claim 8, characterized in that, Methods for calibrating the tilt angle of the surface to be measured include: Adjust the bubble level at the top of the mounting cylinder so that the cycloid is in the direction of the axis of the mounting cylinder, and obtain the position coordinates (x0, y0) of the laser spot; Position coordinates (x) t ,y t ) calibrated to (x t -x0,y t -y0); θ is calibrated using the following formula: (6) In the formula, θ' is the calibrated value; Apply the following formulas to θ respectively x θ y Perform calibration: (7) (8) In the formula, θ' x ,θ' y θ x θ y The calibrated value.

10. A method for tilt measurement using the device of claim 1, characterized in that, Includes the following steps: After the device is placed on the surface to be measured, the laser pendulum unit emits a vertically downward laser beam and forms a laser spot on the photosensitive surface of the PSD sensor; The position measurement unit outputs two voltage signals with amplitudes proportional to the two-dimensional position coordinates of the laser spot. The data acquisition and processing unit converts the voltage signal into a digital signal and calculates the tilt angle of the surface under test by solving the position coordinates of the laser spot.

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