Tilt angle sensor adopting novel suspension mechanical structure and measuring method thereof

Abstract

The invention discloses a tilt angle sensor adopting a novel suspension mechanical structure and a measuring method of the tilt angle sensor. The main structure of the tilt angle sensor comprises a suspension system and a measuring system, the suspension system is composed of a permanent magnet array and a square pyrolytic graphite suspension sheet; the permanent magnet array is composed of four square permanent magnets which are arranged in a staggered mode in the magnetizing direction, and the square pyrolytic graphite suspension sheet is stably suspended in the center of the permanent magnet array. The measurement system is composed of an excitation power supply, a measurement unit, a modulation circuit, a conditioning circuit and a signal collector. The measurement method of the tilt angle sensor comprises the following steps: mounting the tilt angle sensor; debugging the tilt angle sensor; and actually testing the tilt angle sensor. The tilt angle sensor provided by the invention is excellent in static performance and free of mechanical wear, can realize high-precision measurement of a tiny tilt angle, and has the characteristics of high resolution and high sensitivity. The tilt angle sensor overcomes the friction problem generally existing in the conventional tilt angle sensor, and has great advantages in the field of precision measurement of micro tilt angles.

Description

Technical Field

[0001] The invention relates to the field of precision instruments and meters, and in particular to an inclination sensor adopting a novel suspension mechanical structure and a measuring method thereof. Background Art

[0002] As an important angle measurement unit, the inclinometer is widely used in aerospace attitude detection, civil infrastructure health status monitoring, precision instrument manufacturing and other fields. With the continuous development and progress of science and technology, the demand for inclinometers used to measure small angle changes is also increasing. At present, various high-precision and high-resolution inclinometers are gradually being developed, which is one of the hot spots of future precision instrument research.

[0003] At present, the common inclination sensors mainly include electrolyte inclination sensors, capacitive inclination sensors, grating inclination sensors and optical fiber inclination sensors. Electrolyte inclination sensors use the changes in the internal electrolyte level to measure the inclination. They have high accuracy and sensitivity, but are sensitive to temperature changes and external vibrations, have slow response speeds, and are not suitable for dynamic measurements. Capacitive inclination sensors detect inclination by measuring the changes in the distance between capacitor plates. They have the advantages of strong anti-interference ability and high resolution, but have strict installation requirements and are sensitive to ambient interference such as temperature and vibration. Grating inclination sensors use the spectral characteristics of gratings to determine the inclination angle of the sensor. They have the characteristics of high accuracy and strong anti-electromagnetic interference, but their cost is high, and they require complex installation and debugging, and require a stable light source, and their long-term measurement stability is poor. Fiber-optic inclination sensors sense the inclination angle through the bending degree of the optical fiber. They have the advantages of anti-electromagnetic interference, corrosion resistance, and high reliability, but their manufacturing cost is high, installation and maintenance are complex, and they have strict requirements on the installation environment. In addition, the mechanical strength of the optical fiber is poor and it is easily damaged when it is violently vibrated or bent.

[0004] With the continuous development of precision measurement technology and strong magnetic fields, research on magnetic levitation technology has become increasingly rich. Materials with a magnetic susceptibility less than zero have the characteristics of passive stable suspension without external energy input, no friction, low stiffness, etc., making them more and more widely used in energy collectors, high-sensitivity sensors and other fields. In magnetic levitation technology, for materials with a magnetic susceptibility less than zero, they will generate an additional magnetic field under the action of an external magnetic field, and the direction of the additional magnetic field is opposite to that of the external magnetic field. By reasonably arranging the external magnetic field and selecting a suitable material with a magnetic susceptibility less than zero, and combining the two, passive stable suspension of materials with a magnetic susceptibility less than zero can be achieved without external energy input.

[0005] By combining electromagnetic induction effect with magnetic levitation technology, this patent proposes a new type of suspension mechanical structure for measuring small inclination angles of inclination sensors. Before this, few domestic and foreign scholars have combined electromagnetic induction with magnetic levitation technology to carry out research on inclination sensors. Summary of the invention

[0006] In view of the shortcomings of the prior art in the above background, the present invention combines the electromagnetic induction effect with the magnetic levitation technology, and proposes a tilt sensor and a measurement method thereof using a new type of suspension mechanical structure; it realizes the function of precise measurement of tiny tilt angles, overcomes the friction problems and strict environmental requirements commonly existing in the existing tilt sensors, and can achieve precise and stable measurement of tiny tilt angles on the basis of low power consumption.

[0007] In order to achieve the above objectives, the present invention adopts the following technical solutions:

[0008] A tilt sensor adopting a novel suspension mechanical structure is composed of a suspension system and a measurement system; the suspension system specifically includes a permanent magnet array and a square pyrolytic graphite suspension sheet. The measurement system specifically includes a measurement unit, an excitation power supply, a modulation circuit, a conditioning circuit and a signal collector.

[0009] Furthermore, in the suspension system, the permanent magnet array is composed of four square permanent magnets with equal length and width and half the height of the width, and the magnetization directions are staggered, the magnetization directions of adjacent permanent magnets are opposite, and the magnetization intensities are equal. The four square permanent magnets can be naturally attracted together under natural conditions without the help of external forces to form a large square permanent magnet array;

[0010] A peak-shaped magnetic field is generated in the area above the square permanent magnet array, and the square pyrolytic graphite suspension sheet excites magnetic potential energy in the peak-shaped magnetic field, and stably suspends at the point where the total potential energy is the smallest above the permanent magnet array, that is, the center of the permanent magnet array; the total potential energy is composed of magnetic potential energy and gravitational potential energy;

[0011] The measuring unit is composed of two groups of orthogonally arranged planar spiral coils, which are printed on the FPC circuit board. Each group of planar spiral coils is composed of two inductor coils with positive and negative ring structures. The inductor coils rotate in opposite directions and are located in different branches in the modulation circuit to form a differential circuit.

[0012] The modulation circuit is used to convert the position signal of the change of the suspension position of the square pyrolytic graphite suspension sheet caused by the change of the inclination angle into an electrical signal in real time;

[0013] The conditioning circuit is used to perform amplitude detection, differential amplification and low-pass filtering on the electrical signals input from different branches of the modulation circuit.

[0014] Furthermore, the permanent magnet array is made of square permanent magnets made of neodymium iron boron material, and the square pyrolytic graphite suspension sheet is made of pyrolytic graphite with a magnetic susceptibility less than zero.

[0015] Furthermore, the diagonal length of the square pyrolytic graphite suspension sheet is equal to the center distance between two inductor coils in the same group of planar spiral coils in the measurement unit; the thickness of the square pyrolytic graphite suspension sheet is 0.5 times its suspension height in the center of the permanent magnet array.

[0016] Furthermore, when the relative position of the square pyrolytic graphite suspension sheet and the permanent magnet array changes, each branch in the differential circuit converts the position change of the square pyrolytic graphite suspension sheet into a change in the equivalent impedance of the inductor coil in the measuring unit through the modulation circuit and the conditioning circuit, and then outputs a voltage signal about the inclination angle of the sensor, which is collected by the signal collector; and the voltage signal is observed to reflect the size of the inclination angle measured by the sensor.

[0017] A method for measuring an inclination sensor using a novel suspension mechanical structure comprises the following steps:

[0018] Step S1, assembling the tilt sensor;

[0019] Step S2, using the inclination test bench to fully debug the inclination sensor;

[0020] Step S3: Conduct actual testing of the inclination sensor, analyze the output signal of the sensor, compare the test inclination angle with the actual inclination angle, and evaluate the measurement accuracy of the inclination sensor.

[0021] Furthermore, the assembly of the tilt sensor in step S1 is specifically as follows:

[0022] Step S11, staggering the four square permanent magnets with equal magnetization strength to form a permanent magnet array with staggered magnetization directions;

[0023] Step S12, adhering the measuring unit to the permanent magnet array, with the center of the measuring unit aligned with the center of the permanent magnet array;

[0024] Step S13, placing the square pyrolytic graphite suspension sheet in the center of the permanent magnet array, and when it is stably suspended, further adjusting the measuring unit to ensure that the centers of its four inductance coils are aligned with the four corners of the square pyrolytic graphite suspension sheet;

[0025] Step S14: connect the excitation power supply, the modulation circuit, the conditioning circuit and the signal collector in sequence to complete the assembly of the tilt sensor.

[0026] Furthermore, the debugging of the tilt sensor in step S2 is specifically as follows:

[0027] Step S21, using the inclination test bench, inputting the inclination angle of the sensor in sequence according to the test step length, and performing a sensor performance experimental test;

[0028] Step S22, recording and analyzing the performance parameters of the sensor; the performance parameters include input-output curve, range, sensitivity, resolution, and response time; wherein the inclination angle of the sensor is the input of the sensor, the relative displacement of the square pyrolytic graphite suspension sheet causes the change of the output signal of the conditioning circuit, and the signal collected by the signal collector is the output of the sensor;

[0029] Step S23, repeat the above test process multiple times to obtain an average curve and complete the debugging; when actually measuring, the determined sensor performance parameters are used as a carrier, and the inclination angle is determined according to the change in the output signal obtained by the displacement change of the square pyrolytic graphite suspension sheet caused by the inclination angle to be measured.

[0030] Furthermore, the actual test of the tilt sensor in step S3 is specifically as follows:

[0031] Step S31, changing the tilt degree of the tilt sensor, and recording the actual tilt angle of the tilt sensor during each change;

[0032] Step S32, recording the sensor output signal of the structural parameters determined during the process of adjusting the inclination angle;

[0033] Step S33: Compare and analyze the test inclination angle and the actual inclination angle to obtain the measurement accuracy of the inclination sensor and complete the actual test of the inclination sensor.

[0034] Compared with the prior art, the inclination sensor and the measuring method thereof using the novel suspension mechanical structure described in the present invention have the following beneficial effects:

[0035] (1) The inclination sensor proposed in the present invention has excellent static performance, no mechanical wear, fast response speed, and is suitable for static angle measurement. It avoids the shortcomings of electrolyte inclination sensors that are sensitive to temperature changes and external vibrations, have slow response speed, and are not suitable for dynamic measurement.

[0036] (2) Compared with capacitive inclination sensors, the present invention has lower equipment installation requirements and is not easily affected by environmental factors such as temperature and vibration. Compared with grating inclination sensors, the present invention has lower cost, is easier to install and debug, and has stronger long-term measurement stability. In addition, compared with optical fiber inclination sensors, the present invention has lower manufacturing cost, is easier to install and maintain, has high mechanical strength, and is not easily damaged even under severe vibration or bending conditions.

[0037] (3) The present invention combines magnetic levitation technology to achieve passive and stable suspension of square pyrolytic graphite suspension sheets without external energy input, avoiding friction and reducing the power consumption of the sensor. Combining the high sensitivity of the square pyrolytic graphite suspension sheet with electromagnetic induction measurement, the present invention overcomes the friction problems and strict environmental requirements commonly found in existing inclination sensors, and can achieve precise and stable measurement of small inclination angles on the basis of low power consumption. Compared with traditional inclination sensors, the present invention has the advantages of environmental adaptability and measurement accuracy, and can meet the needs of dynamic and static measurements. BRIEF DESCRIPTION OF THE DRAWINGS

[0038] Figure 1 This is a schematic diagram of the overall structure of the tilt sensor proposed by the present invention;

[0039] Figure 2 This is a structural measurement diagram of the suspension system in the tilt sensor proposed by the present invention;

[0040] Figure 3 A top view of the suspension system structure in the tilt sensor proposed by the present invention;

[0041] Figure 4 A schematic diagram of the plane potential energy of the square pyrolytic graphite suspension sheet proposed by the present invention suspended in a permanent magnet array;

[0042] Figure 5 A top view of the measuring unit proposed by the present invention;

[0043] Figure 6 This is the relationship between the horizontal restoring force of the permanent magnet array on the displacement of the square pyrolytic graphite suspension when the inclination sensor is tilted.

[0044] Figure 7 This is a graph showing the relationship between the vertical suspension force of the square pyrolytic graphite suspension sheet and the permanent magnet array when the inclination sensor is tilted;

[0045] Figure 8 Schematic diagram of force analysis of the square pyrolytic graphite suspension sheet when the inclination sensor is tilted.

[0046] Fig. 9 It is a schematic diagram of the input and output curve of the tilt sensor;

[0047] In the figure, 1-permanent magnet array, 2-square pyrolytic graphite suspension sheet, 3-measurement unit, 4-excitation power supply, 5-modulation circuit, 6-conditioning circuit, 7-signal collector; DETAILED DESCRIPTION

[0048] The following is based on the embodiment combined Figure 1-Figure 9The present invention is described, but the present invention is not limited to this specific embodiment. In the detailed description of the present invention below, some specific details are described in detail. For those skilled in the art, the present invention can be fully understood without the description of these details.

[0049] A tilt sensor using a new type of suspension mechanical structure, the overall structure is as follows Figure 1 As shown, it consists of a suspension system and a measuring system.

[0050] Furthermore, the suspension system structure is as follows Figure 2 , Figure 3 As shown, it specifically comprises a permanent magnet array (1) and a square pyrolytic graphite suspension sheet (2).

[0051] Furthermore, the permanent magnet array (1) is composed of four square permanent magnets with equal length and width and a height that is half the width. The magnetization directions are staggered, the magnetization directions of adjacent permanent magnets are opposite, and the magnetization intensity of each permanent magnet is equal. The four square permanent magnets are naturally attracted together without the need for external force to form a large square permanent magnet array.

[0052] Furthermore, the square permanent magnets are all made of neodymium iron boron (NdFeB) material, and the length and width of the four square permanent magnets are 10 mm and the height is 5 mm. The square pyrolytic graphite suspension sheet (2) is made of pyrolytic graphite, a material with a magnetic susceptibility less than zero, and the length and width are both 10 mm and the thickness is 0.4 mm; when the square pyrolytic graphite suspension sheet (2) is stably suspended above the center of the permanent magnet array (1), its suspension height is 0.8 mm.

[0053] Furthermore, in the suspension system structure, a peak-shaped magnetic field is generated in the middle region of the permanent magnet array (1) with staggered magnetization directions, and the square pyrolytic graphite suspension sheet (2) excites magnetic potential energy in the peak-shaped magnetic field, such as Figure 4 As shown, the magnetic potential energy of the square pyrolytic graphite suspension sheet (2) has a minimum point. According to the principle of minimum potential energy, the square pyrolytic graphite suspension sheet (2) can be passively and stably suspended at the minimum potential energy point, that is, in the center of the permanent magnet array (1). At this time, the square pyrolytic graphite suspension sheet (2) is only subjected to the vertical suspension force and its own gravity in the vertical direction. The magnitude of the vertical suspension force is equal to the gravity of the square pyrolytic graphite suspension sheet (2), and the directions are opposite to each other. In this way, the square pyrolytic graphite suspension sheet (2) in the suspension system can be passively and stably suspended. This suspension system structure avoids the negative impact of external friction during the measurement process, and ensures that the square pyrolytic graphite suspension sheet (2), the sensitive element of the inclination sensor, responds freely when the sensor is subjected to inclination.

[0054] Furthermore, the measurement system specifically comprises: a measurement unit (3), an excitation power supply (4), a modulation circuit (5), a conditioning circuit (6) and a signal collector (7).

[0055] The top view of the measuring unit (3) is as follows Figure 5 As shown, the measuring unit (3) is composed of two groups of orthogonally arranged planar spiral coils, which are printed on an FPC circuit board. The same group of planar spiral coils is composed of two inductance coils with positive and negative ring structures, and the rotation directions of the inductance coils are opposite to each other, forming a differential circuit. The differential principle of the modulation circuit (5) is: for the two inductance coils in the same group of planar spiral coils installed in different branches of the modulation circuit (5) in the measuring unit (3), their impedance values ​​change with the change of the relative position between the square pyrolytic graphite suspension sheet and the measuring unit, thereby causing the output voltage of each branch of the differential circuit to change to different degrees, and the position signal of the square pyrolytic graphite suspension sheet can be obtained by differentiating the output voltage. The advantage of the differential circuit is that it can offset the influence of the bias current on the reference value and can effectively reduce the interference of the measurement environment. The modulation circuit (5) is used to convert the position signal of the change of the suspension position of the square pyrolytic graphite suspension sheet (2) caused by the change of the inclination angle into an electrical signal in real time.

[0056] The conditioning circuit (6) is used to perform amplitude detection, differential amplification, and low-pass filtering on the electrical signals input from different branches of the modulation circuit (5).

[0057] Furthermore, when the relative position of the square pyrolytic graphite suspension sheet (2) and the permanent magnet array (1) changes, each branch in the differential circuit converts the position change of the square pyrolytic graphite suspension sheet (2) into a change in the equivalent impedance of the inductor coil in the measuring unit (3) through the modulation circuit (5) and the conditioning circuit (6), and then outputs a voltage signal related to the inclination angle of the sensor, which is collected by the signal collector (7); and the magnitude of the inclination angle measured by the sensor is reflected by observing the voltage signal.

[0058] Furthermore, the inductor coil in the measuring unit is made of brass with a thickness of 2 oz. The outer diameter of a single inductor coil is 1 mm, the number of turns is 6, the line width is 0.2 mm, and the line spacing is 0.6 mm. It is printed on a 0.2 mm thick FPC circuit board. The excitation power supply (4) uses a square wave excitation signal with an input frequency of 1.25 MHz and an amplitude of 10 V.

[0059] Further, the working principle of the tilt sensor is described in detail below:

[0060] In the initial horizontal state, when the square pyrolytic graphite suspension sheet (2) is suspended above the center of the permanent magnet array (1), the square pyrolytic graphite suspension sheet (2) reaches a force balance state, that is:

[0061] F ⊥ =G (1)

[0062] In formula (1), F ⊥ The vertical levitation force of the permanent magnet array (1) with staggered magnetization directions on the square pyrolytic graphite suspension sheet (2) when it is stably suspended is vertically upward, and G is the weight of the square pyrolytic graphite suspension sheet (2) itself, which is vertically downward. These two forces are interaction forces, equal in magnitude and opposite in direction.

[0063] When the inclination angle is θ, and the square pyrolytic graphite suspension sheet (2) is stably suspended above the permanent magnet array (1), the force applied to it is as follows: Figure 6 , Figure 7 As shown, at this time, the square pyrolytic graphite suspension sheet (2) is additionally subjected to a horizontal restoring force F exerted by the permanent magnet array (1). / / When the square pyrolytic graphite suspension is in equilibrium, Figure 8 As shown, the horizontal restoring force F acting on it / / , vertical suspension force F ⊥ It is in equilibrium with its own gravity G, that is:

[0064] F / / +F ⊥ =G (2)

[0065] In formula (2), F / / F is the horizontal restoring force of the permanent magnet array (1) with staggered magnetization directions on the square pyrolytic graphite suspension sheet (2), the direction of which is parallel to the inclined plane and points to the center of the permanent magnet array (1). ⊥ is the vertical suspension force of the permanent magnet array (1) on the square pyrolytic graphite suspension sheet (2), the direction of which is perpendicular to the inclined plane, and G is the weight of the square pyrolytic graphite suspension sheet (2), the direction of which is vertically downward. / / The value increases with the increase of the displacement d of the square pyrolytic graphite suspension sheet (2).

[0066] Figure 6 and Figure 7 The vertical suspension force F on the square pyrolytic graphite suspension sheet is shown. ⊥ and horizontal restoring force F / / The relationship between the sensor and the permanent magnet array caused by the inclination angle θ. As the displacement d increases, the horizontal restoring force F / / and the vertical suspension force F ⊥ In the actual suspension system, the vertical suspension force F ⊥ The change in the horizontal restoring force F is much smaller than / / The change in vertical suspension force F ⊥The change in the vertical suspension force F is much smaller than the gravity G on the square pyrolytic graphite suspension sheet itself. ⊥ The change in the horizontal restoring force F / / The change in the vertical suspension force F can be ignored. ⊥ It can be considered as a constant. Within the range of the inclination sensor, the horizontal restoring force F of the square pyrolytic graphite suspension (2) caused by the inclination ⊥ The change in and displacement d have a good linear relationship. Therefore, formula (3) can be reasonably simplified as:

[0067] k / / F / / d+F ⊥ =G (3)

[0068] In formula (3), k / / is the horizontal restoring force F exerted on the square pyrolytic graphite suspension sheet (2) at different positions / / The coefficient of variation of .

[0069] When the square pyrolytic graphite suspension sheet (2) is stably suspended, according to Figure 8 The schematic diagram of the force balance of the square pyrolytic graphite suspension sheet when it is stably suspended is shown in FIG. 3. The horizontal restoring force F / / and the vertical suspension force F ⊥ The relationship between the gravity converted into the square suspension inclination change and its own mass is:

[0070] k / / mgsinθ·d+mgcosθ=mg (4)

[0071] In formula (4), m is the mass of the square pyrolytic graphite suspension sheet (2), and g is the gravitational constant;

[0072] From this, we can get the relationship between the tilt angle θ of the suspension system and the displacement d of the square pyrolytic graphite suspension sheet (2):

[0073]

[0074] For the measurement system, the differential principle in the differential circuit structure in the measurement unit (3) is that for the inductor coils installed in different branches in the modulation circuit (5), the modulation circuit (5) selects a differential circuit designed based on parallel resonance, and the two inductor coils in the same group of planar spiral coils are distributed on different branches of the differential circuit. When the square pyrolytic graphite suspension sheet is displaced d relative to the measurement unit (3), the impedance value of the inductor coil changes with the change of the relative position of the square pyrolytic graphite suspension sheet and the measurement unit. This causes the voltage of each branch of the modulation circuit (5) to change. The position signal of the square pyrolytic graphite suspension sheet (2) is converted into an electrical signal in real time and transmitted to the conditioning circuit (6). The conditioning circuit (6) processes the electrical signal to obtain an output signal, which is input into the signal collector (7). This reflects the size of the inclination angle of the sensor. The relationship between the output electrical signal of each branch in the modulation circuit (5) and the displacement d of the square pyrolytic graphite suspension sheet (2) is:

[0075] U 1,2 =k(1±d)U in (6)

[0076] Where: U 1,2 These are the output voltages of each branch of the same group of differential coils, and k is the conversion coefficient.

[0077] After the output electrical signal is processed by the sensor conditioning circuit (6) for amplitude detection, differential amplification, and low-pass filtering, the output signal size obtained by the signal collector (7) is:

[0078] U out =K(U1-U2) (7)

[0079] Where: U out is the output signal of the conditioning circuit (6), that is, the signal collected by the signal collector (7), and K is the amplification factor of the amplifier circuit in the conditioning circuit (7).

[0080] The present invention proposes a method for measuring an inclination sensor using a novel suspension mechanical structure, which specifically includes the following steps:

[0081] Step S1, assembling the tilt sensor;

[0082] Step S2, using the inclination test bench to fully debug the inclination sensor;

[0083] Step S3: Conduct actual testing of the inclination sensor, analyze the output signal of the sensor, compare the test inclination angle with the actual inclination angle, and evaluate the measurement accuracy of the inclination sensor.

[0084] Furthermore, the assembly of the tilt sensor in step S1 is specifically as follows:

[0085] Step S11, staggering the four square permanent magnets with equal magnetization strength to form a permanent magnet array (1) with staggered magnetization directions;

[0086] Step S12, adhering the measuring unit (3) to the permanent magnet array (1), with the center of the measuring unit (3) aligned with the center of the permanent magnet array;

[0087] Step S13, placing the square pyrolytic graphite suspension sheet (2) in the center of the permanent magnet array (1), and when it is stably suspended, further adjusting the measuring unit (3) to ensure that the centers of its four inductance coils are aligned with the four corners of the square pyrolytic graphite suspension sheet (2);

[0088] Step S14, connecting the excitation power supply (4), the modulation circuit (5), the conditioning circuit (6) and the signal collector (7) in sequence to complete the assembly of the tilt sensor.

[0089] Furthermore, the debugging of the tilt sensor in step S2 is specifically as follows:

[0090] Step S21, using the inclination test bench, inputting the inclination angle of the sensor in sequence according to the test step length, and performing a sensor performance experimental test;

[0091] Step S22, recording and analyzing the performance parameters of the sensor; the performance parameters include input-output curve, range, sensitivity, resolution, and response time; wherein the inclination angle of the sensor is the input of the sensor, the relative displacement of the square pyrolytic graphite suspension sheet (2) causes the change of the output signal of the conditioning circuit (6), and the signal collected by the signal collector (7) is the output of the sensor;

[0092] Step S23, repeat the above test process multiple times to obtain an average curve and complete debugging; when actually measuring, use the determined sensor performance parameters as a carrier and determine the inclination angle according to the change in the output signal obtained by the displacement change of the square pyrolytic graphite suspension sheet (2) caused by the inclination angle to be measured.

[0093] Furthermore, the actual test of the tilt sensor in step S3 is specifically as follows:

[0094] Step S31, changing the tilt degree of the tilt sensor, and recording the actual tilt angle of the tilt sensor during each change;

[0095] Step S32, recording the sensor output signal of the structural parameters determined during the process of adjusting the inclination angle;

[0096] Step S33: Compare and analyze the test inclination angle and the actual inclination angle to obtain the measurement accuracy of the inclination sensor and complete the actual test of the inclination sensor.

Claims

1. A tilt sensor using a new type of suspension mechanical structure, characterized in that: It is composed of suspension system and measurement system; The suspension system comprises a permanent magnet array (1) and a square pyrolytic graphite suspension sheet (2); the measurement system comprises a measurement unit (3), an excitation power supply (4), a modulation circuit (5), a conditioning circuit (6) and a signal collector (7); The permanent magnet array (1) is composed of four square permanent magnets with the same length and width and a height that is half the width. The magnetization directions are staggered, that is, the magnetization directions of adjacent permanent magnets are opposite, and the magnetization intensities of the permanent magnets are equal. The four square permanent magnets are naturally attracted together without the need for external forces to form a large square permanent magnet array. A peak-shaped magnetic field is generated in the area above the square permanent magnet array, and the square pyrolytic graphite suspension sheet (2) excites magnetic potential energy in the peak-shaped magnetic field and stably suspends at the point where the total potential energy is the smallest above the permanent magnet array, that is, the center of the permanent magnet array; the total potential energy is composed of magnetic potential energy and gravitational potential energy; The measuring unit (3) is composed of two groups of orthogonally arranged planar spiral coils, which are printed on an FPC circuit board; each group of planar spiral coils is composed of two inductance coils with positive and negative ring structures, the inductance coils rotate in opposite directions, and are located in different branches in the modulation circuit (5) to form a differential circuit; The modulation circuit (5) is used to convert the position signal of the change of the suspension position of the square pyrolytic graphite suspension sheet (2) caused by the change of the inclination angle into an electrical signal in real time; The conditioning circuit (6) is used to perform amplitude detection, differential amplification, and low-pass filtering on the electrical signals input from different branches of the modulation circuit (5).

2. The inclination sensor using a novel suspension mechanical structure according to claim 1 is characterized in that: The permanent magnet array (1) uses square permanent magnets made of neodymium iron boron material, and the square pyrolytic graphite suspension sheet (2) is made of pyrolytic graphite with a magnetic susceptibility less than zero.

3. The inclination sensor using a novel suspension mechanical structure according to claim 1 is characterized in that: The diagonal length of the square pyrolytic graphite suspension sheet (2) is equal to the center distance of the inductor coils in the same group of planar spiral coils in the measuring unit (3); the thickness of the square pyrolytic graphite suspension sheet (2) is 0.5 times its suspension height in the center of the permanent magnet array (1).

4. The inclination sensor using a novel suspension mechanical structure according to claim 1 is characterized in that: When the relative position of the square pyrolytic graphite suspension sheet (2) and the permanent magnet array (1) changes, each branch in the differential circuit converts the position change of the square pyrolytic graphite suspension sheet (2) into a change in the equivalent impedance of the inductor coil in the measuring unit (3) through a modulation circuit (5) and a conditioning circuit (6), and then outputs a voltage signal related to the inclination angle of the sensor, which is collected by a signal collector (7); and the magnitude of the inclination angle measured by the sensor is reflected by observing the voltage signal.

5. A tilt sensor using a novel suspension mechanical structure according to any one of claims 1 to 4, and a method for measuring a tilt sensor using a novel suspension mechanical structure, characterized in that: The following steps are involved: Step S1, assembling the tilt sensor; Step S2, using the inclination test bench to fully debug the inclination sensor; Step S3: Conduct actual testing of the inclination sensor, analyze the output signal of the sensor, compare the test inclination angle with the actual inclination angle, and evaluate the measurement accuracy of the inclination sensor.

6. The measuring method of the inclination sensor using the novel suspension mechanical structure according to claim 5 is characterized in that: The assembly of the tilt sensor in step S1 is specifically as follows: Step S11, staggering the four square permanent magnets with equal magnetization strength to form a permanent magnet array (1) with staggered magnetization directions; Step S12, adhering the measuring unit (3) to the permanent magnet array (1), with the center of the measuring unit (3) aligned with the center of the permanent magnet array; Step S13, placing the square pyrolytic graphite suspension sheet (2) in the center of the permanent magnet array (1), and when it is stably suspended, further adjusting the measuring unit (3) to ensure that the centers of its four inductance coils are aligned with the four corners of the square pyrolytic graphite suspension sheet (2); Step S14, connecting the excitation power supply (4), the modulation circuit (5), the conditioning circuit (6) and the signal collector (7) in sequence to complete the assembly of the tilt sensor.

7. The measuring method of the inclination sensor using the novel suspension mechanical structure according to claim 5 is characterized in that: The debugging of the tilt sensor in step S2 is specifically as follows: Step S21, using the inclination test bench, inputting the inclination angle of the sensor in sequence according to the test step length, and performing a sensor performance experimental test; Step S22, recording and analyzing the performance parameters of the sensor; the performance parameters include input-output curve, range, sensitivity, resolution, and response time; wherein the inclination angle of the sensor is the input of the sensor, the relative displacement of the square pyrolytic graphite suspension sheet (2) causes the change of the output signal of the conditioning circuit (6), and the signal collected by the signal collector (7) is the output of the sensor; Step S23, repeat the above test process multiple times to obtain an average curve and complete debugging; when actually measuring, use the determined sensor performance parameters as a carrier and determine the inclination angle according to the change in the output signal obtained by the displacement change of the square pyrolytic graphite suspension sheet (2) caused by the inclination angle to be measured.

8. The measuring method of the inclination sensor using a novel suspension mechanical structure according to claim 5 is characterized in that: The actual test of the tilt sensor in step S3 is as follows: Step S31, changing the tilt degree of the tilt sensor, and recording the actual tilt angle of the tilt sensor during each change; Step S32, recording the sensor output signal of the structural parameters determined during the process of adjusting the inclination angle; Step S33: Compare and analyze the test inclination angle and the actual inclination angle to obtain the measurement accuracy of the inclination sensor and complete the actual test of the inclination sensor.

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