A multi-degree-of-freedom motor attitude detection sensor and method based on photosensitive semiconductor materials.

Abstract

This invention provides a multi-degree-of-freedom (DOF) motor attitude detection sensor and a method for multi-DOF motor attitude detection based on photosensitive semiconductor materials. The non-contact attitude detection of multi-DOF motors based on this sensor exhibits high response speed, effectively improving the latency problem inherent in visual sensor detection. It can perform online attitude detection and be applied to the control circuit of multi-DOF motors. No components need to be placed inside the multi-DOF motor; only a laser source needs to be installed on the motor output shaft to achieve motor attitude detection, effectively avoiding the motion singularity problem of optical sensor methods and the accuracy problem of Hall effect sensor methods.

Description

Technical Field

[0001] This invention belongs to the field of sensors, and particularly relates to a multi-degree-of-freedom motor attitude detection sensor based on photosensitive semiconductor materials and a multi-degree-of-freedom motor attitude detection method. Background Technology

[0002] With the rapid development of industrial automation and the increase in labor costs, industrial robots, industrial gimbals, and other devices capable of performing high-precision servo motion in multiple degrees of freedom have been widely used. Existing multi-degree-of-freedom motion devices are mainly composed of multiple single-degree-of-freedom motion devices combined through a transmission mechanism, which suffers from problems such as complex mechanical structures, large rotational inertia, and low dynamic response accuracy. Multi-degree-of-freedom motors, which can perform deflection and pitch movements with a single mechanism, have attracted widespread attention due to their compact spherical structure design, lack of mechanical transmission requirements, and simple operating principle.

[0003] To achieve high-precision real-time closed-loop control of multi-degree-of-freedom motors, three major problems need to be solved: first, establishing an electromagnetic torque model; second, completing real-time attitude detection; and third, realizing high-speed drive control. The accuracy of the system's closed-loop control is positively correlated with the accuracy of real-time attitude detection. Traditional attitude detection methods can be divided into three categories based on whether the detection device is in contact with the rotor: contact detection (detection device and rotor interconnected), non-contact detection (detection device and rotor separated), and sensorless detection (no dedicated detection device). Among these, non-contact detection is better suited to the special spherical structure of multi-degree-of-freedom motors and does not affect their operation. Four commonly used methods are:

[0004] Firstly, feature codes are sprayed onto the surface of the spherical rotor of the motor, and visual sensors are used to identify the feature codes and then calculate the rotor attitude.

[0005] Secondly, optical sensors are deployed to capture the light signals reflected from the surface of the motor's spherical rotor. The optical sensors convert the light signals into displacement signals and then calculate the rotor attitude.

[0006] Third, a microelectromechanical sensor system is installed on the output shaft connected to the rotor to output triaxial acceleration, velocity, and Euler angles, thereby calculating the rotor attitude;

[0007] Fourth, the magnetic field distribution of the rotor poles is detected by deploying Hall sensors, and the rotor attitude is calculated by analyzing the sensor output code.

[0008] The existing technology has the following disadvantages:

[0009] (1) The visual sensor method requires the acquisition of a large number of images for analysis and processing. Due to the processing speed, online attitude detection is difficult to achieve and it is difficult to use for closed-loop control of multi-degree-of-freedom motors.

[0010] (2) The optical sensor method requires sensors to be placed close to the rotor to capture the light signal reflected from the rotor surface, which is prone to generating motion singularities and is not conducive to multi-degree-of-freedom motors achieving motion in multiple degrees of freedom.

[0011] (3) The output signal of the microelectromechanical sensor method has a zero-point offset error that accumulates over time, and the error needs to be corrected frequently. It is not very applicable in the actual control process of multi-degree-of-freedom motors.

[0012] (4) The Hall sensor method requires the sensor group to be placed close to the magnetic pole. Due to the limited space inside the motor, the Hall sensors cannot be densely distributed, thus limiting the detection accuracy. Summary of the Invention

[0013] This invention provides a multi-degree-of-freedom (DOF) motor attitude detection sensor based on photosensitive semiconductor materials. This sensor enables non-contact attitude detection of DDF motors with high response speed, effectively improving the latency problem inherent in visual sensor detection. It can perform online attitude detection and be applied to the control of DDF motors. No components need to be placed inside the DDF motor; only a laser source needs to be installed on the motor's output shaft to achieve motor attitude detection, effectively avoiding the motion singularity problem of optical sensor methods and the accuracy problem of Hall sensor methods. Based on the good directivity of the laser source and the stable mapping relationship between the input sensor's optical signal and the output electrical signal, this sensor has good detection accuracy and stability, effectively avoiding the zero-point offset error problem of microelectromechanical (MEMS) sensor methods. Detection accuracy increases with the number of photosensitive units swept by the laser per unit angle of motor movement. While keeping the sensor size and installation position constant, the detection accuracy can be improved by reducing the size of the photosensitive units to increase their density; conversely, while keeping the photosensitive unit size and density constant, increasing the installation distance between the sensor and the DDF motor, while simultaneously increasing the number of photosensitive units, also improves detection accuracy. Therefore, the sensor's detection accuracy is stable and controllable.

[0014] This invention provides a multi-degree-of-freedom (DOF) motor attitude detection sensor based on photosensitive semiconductor materials. It detects the position of the multi-DOF motor by detecting the illumination of a laser emitted from its output shaft onto the sensor. The sensor consists of three components: a photosensitive module for receiving laser signals from the multi-DOF motor and performing photoelectric conversion; a signal acquisition module for converting the N*N voltage signals generated by the photosensitive module into 2*N voltage signals via row and column signal buses, reducing signal acquisition complexity; and an analog-to-digital conversion module for converting the 2*N voltage signals output from the signal acquisition module into digital signals for transmission to a host computer, thus achieving attitude detection.

[0015] Furthermore, the photosensitive module consists of three components: a positive electrode circuit, cadmium sulfide, and a negative electrode circuit. The positive electrode circuits in rows N+1 and columns N+1 are each r wide, forming N*N squares of width c. A hole is punched in the center of each square, and N*N negative electrode circuits are inserted therein. The cadmium sulfide layer is attached to the ceramic substrate and together with the positive and negative electrode circuits, forms N*N photosensitive units.

[0016] Furthermore, when the photosensitive unit on the photosensitive module is irradiated by a laser source emitted from the output shaft of the multi-degree-of-freedom motor, the cadmium sulfide in the photosensitive unit generates an internal photoelectric effect, causing its resistance to decrease significantly, and the resistance between the positive electrode line and the negative electrode line decreases; the multi-degree-of-freedom motor attitude detection sensor realizes the conversion of optical signals to electrical signals by detecting this resistance change based on the internal photoelectric effect.

[0017] Furthermore, the signal acquisition module employs a printed circuit, which contains N*N sets of independent resistor-diode assemblies. The negative electrode lines on the photosensitive module are connected to the N*N negative electrode line pads on the signal acquisition module, forming N*N voltage divider circuits with the voltage divider resistors R in the resistor-diode assemblies. The other end of the voltage divider resistors R is grounded. The diodes in the signal acquisition module are used to isolate the row and column signal buses, and also to isolate the signals between the N*N voltage divider circuits to ensure stable detection. The negative electrode line pads are located at the midpoint of the voltage divider circuits, which is designated as the signal acquisition point. When cadmium sulfide is irradiated by a laser, the voltage at the signal acquisition point is pulled high. At this time, two diodes conduct simultaneously, independently sending the pulled-up voltage signals to the corresponding row and column signal buses. Conversely, the bus voltage approaches 0, and the voltage signals are reduced from N*N to 2*N, thus reducing the number of signal acquisitions.

[0018] Furthermore, the analog-to-digital conversion module acquires 2*N voltage signals from the signal acquisition module, converts the analog quantities into digital quantities u, and transmits them to the host computer to form a voltage matrix u. The host computer judges and encodes the elements in the voltage matrix u according to a preset voltage threshold d. The encoding constraint is as follows:

[0019]

[0020] The voltage matrix u is:

[0021]

[0022] Form the encoding matrix τ;

[0023]

[0024] The host computer determines the location of the photosensitive unit on the sensor that is illuminated by the laser source based on the encoding matrix τ, and calculates the real-time attitude of the motor by combining the relative installation position of the sensor and the tested multi-degree-of-freedom motor.

[0025] Furthermore, a method for detecting the attitude of a multi-degree-of-freedom motor based on the aforementioned sensor is provided, comprising the following steps:

[0026] Step 1: The laser source on the output shaft of the multi-degree-of-freedom motor illuminates the photosensitive module of the sensor.

[0027] Step 2: The resistance of cadmium sulfide in the photosensitive unit on the photosensitive module decreases;

[0028] Step 3: On the signal acquisition module, the voltage at the signal acquisition point of the voltage divider circuit irradiated by the laser source is pulled up;

[0029] Step 4: The diode turns on and pulls the corresponding row and column signal bus voltage high, while the voltages of the remaining row and column signal buses approach 0;

[0030] Step 5: The N*N voltage signals are converted into 2*N voltage signals through the row and column signal buses;

[0031] Step 6: The analog-to-digital converter module acquires 2*N voltage signals from the row and column signal buses;

[0032] Step 7: Convert the analog voltage signal into a digital signal u and transmit it to the host computer. The host computer judges and encodes the elements in the voltage matrix u according to the preset voltage threshold d. The encoding constraint is as follows:

[0033]

[0034] The voltage matrix u is:

[0035]

[0036] Form the encoding matrix τ;

[0037]

[0038] Step 8; The host computer determines the location of the photosensitive unit on the sensor that is illuminated by the laser source based on the encoding matrix τ. When a photosensitive unit is illuminated, the corresponding encoding matrix τ... i τ j Encoded as 1, τ at other positions i τ j The code is 0; the relative position of the i-th row and j-th column photosensitive unit on the photosensitive module is determined based on the width r of the positive electrode line of the photosensitive module and the side length c of cadmium sulfide, and then the attitude of the multi-degree-of-freedom motor is calculated.

[0039] When a multi-degree-of-freedom motor completes a 2-degree-of-freedom motion including yaw and pitch, the angle between the output shaft of the multi-degree-of-freedom motor and the vertical line is: The pitch angle to the pitch motion plane γ is β, and the deflection angle to the yaw motion plane δ is α. The vertical length L is the shortest distance between the center of the motor rotor ball and the center of the sensor. The sensor's photosensitive module is designed with N*N photosensitive units, and the calculated side length q of the photosensitive module is:

[0040] q = c*N + r*(N+1),

[0041] Initially, the output shaft normal coincides with the vertical line, and its extension passes through the geometric center of the sensor. The corner closest to the row and column signal bus of i,j=1 is taken as the origin of the sensor coordinates (0,0). When N is odd, the center coordinates of the sensor are:

[0042]

[0043] When the photosensitive unit illuminated by the laser source is σ i,j , when i,j=1,2,3···,N, σ i,j The projections of the distance k from the center of the sensor onto the two-degree-of-freedom planes δ and γ, respectively, are a and b, which can be expressed as:

[0044]

[0045] The angular displacements of the output shaft of the multi-degree-of-freedom motor in the two degrees of freedom directions are as follows:

[0046]

[0047] The attitude information of the multi-degree-of-freedom motor, including its yaw angle and pitch angle, is obtained.

[0048] The beneficial effects of the technical solution of this invention are as follows:

[0049] This multi-degree-of-freedom motor attitude detection sensor, based on photosensitive semiconductor materials, can detect motor attitude in a non-contact manner. Its advantages include: no need for extensive computation or modeling; fast detection speed; real-time online detection; and applicability to motor control. The sensor is deployed outside the motor, detecting its attitude via a laser source on the motor's output shaft, eliminating motion singularities. Detection accuracy is positively correlated with the number of photosensitive units swept by the laser per unit angle of motor movement; this accuracy can be improved by reducing the size and density of the photosensitive units, increasing the distance between the sensor and the multi-degree-of-freedom motor, and increasing the number of photosensitive units, thus ensuring controllable detection accuracy. Detection speed is primarily related to the acquisition rate of the analog-to-digital converter (ADC); this speed can be further reduced by optimizing the signal acquisition sequence of the ADC through algorithms, thereby improving detection speed. Attached Figure Description

[0050] Figure 1This is a structural diagram of a multi-degree-of-freedom motor attitude detection sensor based on photosensitive semiconductor materials, including a photosensitive module, a signal acquisition module, and an analog-to-digital conversion module;

[0051] Figure 2 This is a schematic diagram of the photosensitive module structure provided in an embodiment of the present invention;

[0052] Figure 3 This is a schematic diagram of the signal acquisition module structure provided in an embodiment of the present invention;

[0053] Figure 4 This is a schematic diagram of a single voltage divider circuit model provided in an embodiment of the present invention;

[0054] Figure 5 This is a schematic diagram illustrating the principle of multi-degree-of-freedom motor attitude calculation provided in an embodiment of the present invention;

[0055] Figure 6 The flowcharts for sensor-based photoelectric detection and host computer-based attitude calculation are provided for embodiments of the present invention. Detailed Implementation

[0056] The present invention will be further described below with reference to the accompanying drawings and embodiments.

[0057] This invention provides a multi-degree-of-freedom motor attitude detection sensor based on photosensitive semiconductor materials. It achieves attitude detection of the multi-degree-of-freedom motor by detecting the position of the laser emitted from the output shaft of the motor as it illuminates the sensor. (See attached image) Figure 1 The attitude detection sensor according to this embodiment of the invention consists of three components: a photosensitive module with N*N photosensitive units, each capable of receiving laser signals from a multi-degree-of-freedom motor and performing photoelectric conversion; a signal acquisition module that converts the N*N voltage signals generated by the photosensitive module into 2*N voltage signals via row and column signal buses, reducing signal acquisition complexity; and an analog-to-digital conversion module that acquires the 2*N voltage signals output by the signal acquisition module, converts them into digital signals, and transmits them to a host computer for signal processing to achieve attitude detection. (Appendix) Figure 1 Let N = 3.

[0058] The sensor's photosensitive module consists of three components: a positive electrode circuit, cadmium sulfide (CdS) circuitry, and a negative electrode circuitry. The module is based on a direct-bonded copper-coated alumina (Al2O3) ceramic substrate, on which an etching process is used to fabricate the following... Figure 2 The N+1 rows and N+1 columns of positive electrode lines shown are connected to the positive terminal of a DC power supply. The line width is r, forming N*N squares of width c. After punching a hole in the center of each square, N*N negative electrode lines are inserted.

[0059] Cadmium sulfide (CdS) photosensitive semiconductor material is deposited in an N*N grid using a mask and liquid phase deposition process. After deposition, epoxy resin is coated on the surface of the photosensitive module to achieve moisture protection and protection for the semiconductor material. The cadmium sulfide layer adheres to the ceramic substrate and, together with the positive and negative electrode circuits, constitutes N*N photosensitive units.

[0060] When the photosensitive unit on the photosensitive module is irradiated by a laser source emitted from the output shaft of the multi-degree-of-freedom motor, the cadmium sulfide (CdS) within the photosensitive unit generates an internal photoelectric effect, causing a significant decrease in its resistance, and thus a decrease in the resistance between the positive and negative electrode lines. The multi-degree-of-freedom motor attitude detection sensor converts optical signals into electrical signals by detecting this resistance change based on the internal photoelectric effect.

[0061] The sensor's signal acquisition module relies on, for example Figure 3 The printed circuit board shown contains N*N independent resistor-diode assemblies, including voltage divider resistors R and diodes. The negative electrode lines of the N*N photosensitive units on the photosensitive module are connected to the N*N negative electrode line pads on the signal acquisition module, forming N*N voltage divider resistors R in the resistor-diode assemblies. Figure 4 The voltage divider circuit shown has the other end of the voltage divider resistor R grounded.

[0062] The printed circuit board has N row signal buses and N column signal buses. For example... Figure 4 As shown, the negative electrode pad is located at the midpoint of the voltage divider circuit, which serves as the signal acquisition point. Each signal acquisition point has two signal lines, connected to the corresponding row and column signal buses via 1N4001 diodes. The diodes in the signal acquisition module isolate the row and column signal buses, and also isolate the signals between the N*N voltage divider circuits to ensure stable detection. When cadmium sulfide is irradiated by a laser, the voltage at the signal acquisition point at the midpoint of the voltage divider circuit is pulled high, and both diodes conduct simultaneously, independently sending the pulled-up voltage signals to the corresponding row and column signal buses. Conversely, the bus voltage approaches 0. Therefore, by acquiring a total of 2*N voltage signals from N row and N column signal buses, the voltages of the N*N voltage divider circuit signal acquisition points can be derived using a coordinate method, significantly reducing the signal acquisition burden and achieving a reduction in the number of signal acquisition points.

[0063] The sensor's analog-to-digital conversion module acquires 2*N voltage signals via its uplink and column signal buses. These analog signals are converted into digital signals u and transmitted to the host computer, forming a voltage matrix u. The host computer then judges and encodes the elements in the voltage matrix u according to a preset voltage threshold d, encoding the voltage signals as 0 or 1. The encoding constraints are as follows:

[0064]

[0065] The voltage matrix u is:

[0066]

[0067] The row and column voltage signals are encoded into a two-dimensional matrix with 2 rows and N columns, forming the encoding matrix τ.

[0068]

[0069] The host computer determines the location of the photosensitive unit on the sensor illuminated by the laser source based on the encoding matrix τ. Combining this with the relative installation position of the sensor and the tested multi-degree-of-freedom motor, it calculates the motor's real-time attitude. The specific steps are as follows:

[0070] S1: When a photosensitive unit is illuminated, the corresponding τ in the encoding matrix τ... i τ j Encoded as 1, τ at other positions i τ j The code is 0. According to... Figure 2 The photosensitive module shown has a positive electrode line width of r and a cadmium sulfide side length of c. The relative position of the i-th row and j-th column photosensitive unit under illumination on the photosensitive module is determined, and then the attitude of the multi-degree-of-freedom motor is calculated.

[0071] S2: The attitude calculation process of a multi-degree-of-freedom motor is as follows: Figure 5 As shown. When a multi-degree-of-freedom motor completes a 2-degree-of-freedom motion including yaw and pitch, the angle between the output shaft of the multi-degree-of-freedom motor and the vertical line is... Let β be the pitch angle decomposed to the pitch motion plane γ, and α be the deflection angle decomposed to the yaw motion plane δ. Let L be the shortest distance between the center of the motor rotor ball and the center of the sensor. Let k be the distance between the photosensitive unit irradiated by the laser and the center of the sensor. Then, the projections a and b of k in the δ and γ planes can be solved by geometric calculations.

[0072] according to Figure 2 The sensor's photosensitive module is designed with N*N photosensitive units. The side length q of the photosensitive module is calculated as follows:

[0073] q = c*N + r*(N+1),

[0074] In the initial state, the output shaft normal coincides with the vertical line shown, and its extension passes through the geometric center of the sensor. Figure 3 The corner closest to the row and column signal bus with a distance of i,j=1 is taken as the origin of the sensor coordinates (0,0). When N is odd, the center coordinates of the sensor are:

[0075]

[0076] When the photosensitive unit illuminated by the laser source is σ i,j , when i,j=1,2,3···,N, σ i,j The projections of the distance k from the center of the sensor onto the two-degree-of-freedom planes δ and γ, respectively, are a and b, which can be expressed as:

[0077]

[0078] S3: The attitude of a multi-degree-of-freedom motor can be expressed as the angular displacement of the output shaft in the two degrees of freedom of yaw and pitch motion, respectively:

[0079]

[0080] S4: The workflow of a multi-degree-of-freedom motor attitude detection sensor based on photosensitive semiconductor materials is as follows: Figure 6 As shown, photoelectric detection is performed by a sensor, converting the light signal when irradiated by a laser into a voltage signal. The host computer encodes the voltage signal and calculates the attitude information of the multi-degree-of-freedom motor, including the yaw and pitch angles.

[0081] Those skilled in the art will readily understand that the above description is merely a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of the present invention should be included within the scope of protection of the present invention.

Claims

1. A multi-degree-of-freedom motor attitude detection sensor based on photosensitive semiconductor material, which realizes attitude detection of the multi-degree-of-freedom motor by detecting the illumination position of a laser emitted from the output shaft of the multi-degree-of-freedom motor on the sensor; characterized in that, It consists of three components: a photosensitive module, used to receive laser signals from a multi-degree-of-freedom motor and perform photoelectric conversion; a signal acquisition module, which converts the N signals generated by the photosensitive module into electrical signals; and a signal acquisition module. N voltage signals are converted into 2 through row and column signal buses. N voltage signals reduce signal acquisition burden; The analog-to-digital converter module converts the signal from the signal acquisition module into digital signal. N voltage signals are converted into digital quantities and transmitted to the host computer for signal processing to achieve attitude detection; The signal acquisition module uses printed circuits, and the printed circuits have N N sets of independent resistor-diode assemblies; the negative electrode circuit on the photosensitive module and the N... The N negative electrode pads are connected to form an N-type resistor-diode assembly with the voltage divider resistor R. N voltage divider circuits, with the other end of the voltage divider resistor R grounded; the diodes in the signal acquisition module are used to isolate the row and column signal buses, and simultaneously... Signal isolation is provided among the N voltage divider circuits to ensure stable detection. The negative electrode pad is located at the midpoint of the voltage divider circuit, which serves as the signal acquisition point. When cadmium sulfide is irradiated by a laser, the voltage at the signal acquisition point is pulled high. At this time, two diodes conduct simultaneously, independently sending the pulled-up voltage signal to the corresponding row and column signal buses. Conversely, when the signal bus voltage approaches 0, the voltage signal is transferred from N... N becomes 2 N signals are used to reduce the number of signal acquisitions. The analog-to-digital conversion module acquires signals from the acquisition module. N voltage signals are converted from analog to digital quantities u and transmitted to a host computer to form a voltage matrix u. The host computer judges and encodes the elements in the voltage matrix u according to a preset voltage threshold d. The encoding constraints are as follows: ， The voltage matrix u is: ， The row and column voltage signals are encoded into a two-dimensional matrix of two rows and n columns, forming an encoding matrix. ; ； The host computer uses the encoding matrix The location of the photosensitive unit on the sensor that is illuminated by the laser source is determined, and the real-time attitude of the motor is calculated by combining the relative installation positions of the sensor and the multi-degree-of-freedom motor under test.

2. The sensor according to claim 1, characterized in that, The photosensitive module consists of three components: a positive electrode circuit, cadmium sulfide, and a negative electrode circuit; the positive electrode circuits in rows N+1 and columns N+1 are each r wide, forming an N-axis array. N squares of width c are formed, and a hole is punched in the center of each square to insert N... N negative electrode lines; a cadmium sulfide layer is attached to the ceramic substrate, together with the positive and negative electrode lines, forming N... N photosensitive units.

3. The sensor according to claim 1, characterized in that, When the photosensitive unit on the photosensitive module is irradiated by a laser source emitted from the output shaft of the multi-degree-of-freedom motor, the cadmium sulfide in the photosensitive unit generates an internal photoelectric effect, which causes its resistance to decrease significantly, and the resistance between the positive electrode line and the negative electrode line decreases; the multi-degree-of-freedom motor attitude detection sensor realizes the conversion of optical signal to electrical signal by detecting this resistance change based on the internal photoelectric effect.

4. A method for detecting the attitude of a multi-degree-of-freedom motor based on the sensor described in any one of claims 1-3, characterized in that, Includes the following steps, Step 1: The laser source on the output shaft of the multi-degree-of-freedom motor illuminates the photosensitive module of the sensor. Step 2: The resistance of cadmium sulfide in the photosensitive unit on the photosensitive module decreases; Step 3: On the signal acquisition module, the voltage at the signal acquisition point of the voltage divider circuit irradiated by the laser source is pulled up; Step 4: The diode turns on and pulls the corresponding row and column signal bus voltage high, while the voltages of the remaining row and column signal buses approach 0. Step 5, N N voltage signals are converted into 2 through row and column signal buses. N voltage signals; Step 6: The analog-to-digital conversion module acquires 2 signals from the row and column signal buses. N voltage signals; Step 7: Convert the analog voltage signal into a digital signal u and transmit it to the host computer to form a voltage matrix u. The host computer judges and encodes the elements in the voltage matrix u according to the preset voltage threshold d. The encoding constraint is as follows: ， The voltage matrix u is: ， Forming an encoding matrix ; ； Step 8; The host computer uses the encoding matrix... To determine the location of the photosensitive units on the sensor that are illuminated by a laser source, when a photosensitive unit is illuminated, the corresponding encoding matrix... , Encoded as 1, other positions , The code is 0; the relative position of the i-th row and j-th column photosensitive unit on the photosensitive module is determined based on the width r of the positive electrode line of the photosensitive module and the side length c of cadmium sulfide, and then the attitude of the multi-degree-of-freedom motor is calculated. When a multi-degree-of-freedom motor completes a 2-degree-of-freedom motion including yaw and pitch, the angle between the output shaft of the multi-degree-of-freedom motor and the vertical line is: The pitch angle decomposed to the pitch plane γ is β, and the deflection angle decomposed to the yaw plane δ is α. The vertical length L is the shortest distance between the center of the motor rotor sphere and the center of the sensor. The sensor's photosensitive module is designed with N... Given N photosensitive units, the side length q of the photosensitive module is calculated as follows: , Initially, the output shaft normal coincides with the vertical line, and its extension passes through the geometric center of the sensor. The corner closest to the row and column signal buses i,j=1 is taken as the sensor coordinate origin (0,0). When N is odd, the center coordinates of the sensor are: ； When the photosensitive unit is illuminated by the laser source , hour, The projections of the distance k from the center of the sensor onto the two-degree-of-freedom planes δ and γ, respectively, are a and b, which can be expressed as: ， ； The angular displacements of the output shaft of the multi-degree-of-freedom motor in the two degrees of freedom directions are as follows: , The attitude information of the multi-degree-of-freedom motor, including its yaw angle and pitch angle, is obtained.

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