Quick stabilization method for scale factor of quartz flexible accelerometer

Abstract

The application provides a quartz flexible accelerometer scale factor rapid stabilization processing method, which realizes scale factor rapid stabilization processing through stabilization processing of torque generator air gap magnetic density, so as to solve the technical problems of long time consumption, low efficiency, long time occupation of equipment and limited processing of internal unstable magnetic domain of samarium-cobalt magnetic steel in the prior art. The method comprises the following steps: S1, determining demagnetization voltage X of a torque generator to be processed e ; S2, performing demagnetization stabilization processing: S2.1, placing a plurality of torque generators to be processed in a coil cylinder of a magnetizing and demagnetizing machine, setting a magnetizing voltage, and performing magnetization to saturation; S2.2, selecting a direction opposite to the magnetization in step S2.1, placing the plurality of torque generators to be processed, which are magnetized to saturation in step S2.1, in the coil cylinder of the magnetizing and demagnetizing machine, setting a demagnetization voltage as X e , and performing demagnetization stabilization processing; and S2.3, taking out the plurality of torque generators to be processed after the demagnetization stabilization processing, and repeating steps S2.1 to S2.2 until the demagnetization stabilization processing of the torque generators to be processed in the batch is completed.

Description

Technical Field

[0001] This invention relates to quartz flexible accelerometers, and more specifically to a method for rapidly stabilizing the scale factor of quartz flexible accelerometers. Background Technology

[0002] Quartz flexural accelerometers, as key sensor units in inertial navigation systems, are mainly used to detect the linear motion information of a vehicle. A quartz flexural accelerometer consists of an upper torque unit, a lower torque unit, a pendulum assembly, an isolation ring, a servo circuit, and a housing. The upper and lower torque units (hereinafter referred to as torque units) adopt a top-down arrangement of corresponding magnetic poles, forming a uniform magnetic field in the gap, providing the magnetic energy source for the moving coil of the pendulum assembly to operate.

[0003] The scaling factor K1 is the ratio of the output to the input of a quartz flexure accelerometer, and its long-term repeatability is a core indicator for the application of quartz flexure accelerometers in the field of inertial navigation. The formula for calculating the scaling factor K1 is shown in equation (1).

[0004]

[0005] Many factors affect the long-term repeatability of the scaling factor K1. Among them, the attenuation of the torque air gap magnetic flux density B is the key factor affecting the long-term repeatability of the scaling factor K1. As can be seen from equation (1), the attenuation of the magnetic properties of the magnet in the torque will lead to a decrease in the torque air gap magnetic flux density B at the working position of the pendulum assembly, which in turn causes the scaling factor K1 to drift continuously towards a larger value. In order to improve the long-term repeatability of the scaling factor K1 of the quartz flexible accelerometer from the source, samarium cobalt magnets with large coercivity have become the preferred choice in the accelerometer industry.

[0006] like Figure 2 As shown, torque converter 07 mainly includes a yoke 08, a samarium cobalt magnet 09, and magnetic pole pieces 010. After the torque converter 07 is assembled, it is magnetized in a certain direction using a magnetizer. The samarium cobalt magnet 09 then acquires polarity. The main magnetic flux of torque converter 07 forms a closed loop from the N pole of the samarium cobalt magnet 09 through the magnetic pole pieces 010, the air gap 011, and the yoke 08 to the S pole of the samarium cobalt magnet 09. The energy of the magnetic circuit originates from the samarium cobalt magnet 09; therefore, the stability of its magnetic properties mainly depends on the samarium cobalt magnet 09. After magnetization, due to changes in its internal structure, the unstable magnetic domains within the samarium cobalt magnet 09 undergo irreversible changes over time and under external conditions, leading to a decay in the magnetic properties of the samarium cobalt magnet 09, which in turn causes the scaling factor K1 to increase. Therefore, in order to achieve rapid stabilization of the accelerometer scaling factor K1, necessary stabilization techniques are adopted for the torque generator using samarium cobalt magnets during the accelerometer assembly stage. This process aims to address the attenuation of its magnetic properties over time and under external conditions as early as possible, minimizing its variation over time during later use and storage. This ensures the long-term repeatability of the accelerometer's scaling factor K1 during use and storage.

[0007] Chinese patent CN106556716B discloses a method for stabilizing a quartz flexible accelerometer torque converter. The method involves adjusting a high-frequency vibration table to 10kHz–20kHz, setting the vibration magnitude to 1g–5g, and performing high-frequency fixed-frequency vibration for 2–5 hours. Data is collected during the vibration process using a high-speed continuous acquisition system. The accelerometer torque converter undergoes temperature shock stabilization by cycling it at -40℃ to 120℃ for 3–5 cycles. Finally, the accelerometer torque converter undergoes high-temperature stabilization by placing it in a 100℃–160℃ temperature chamber for 5–10 hours. However, the existing technology has the following drawbacks: 1) It is time-consuming, inefficient, and requires a lot of equipment for a long time; 2) The unstable magnetic domains inside the samarium cobalt magnet can only be stabilized at temperatures above 300°C. However, after the torque motor is assembled, the temperature setting is limited due to the adhesive used during the assembly of each part (the high temperature is only 160°C). This results in only the release of assembly stress being achieved, and the treatment of the unstable magnetic domains inside the samarium cobalt magnet is very limited. Summary of the Invention

[0008] The purpose of this invention is to solve the technical problems of existing methods for stabilizing the scaling factor of quartz flexible accelerometers, such as long processing time, low efficiency, long-term occupation of a lot of equipment, and very limited processing of unstable magnetic domains inside samarium cobalt magnets due to the constraint of the torque device by the adhesive. The invention provides a method for rapid stabilization of the scaling factor of quartz flexible accelerometers.

[0009] To achieve the above objectives, the present invention adopts the following technical solution:

[0010] A method for rapidly stabilizing the scaling factor of a quartz flexible accelerometer, wherein the quartz flexible accelerometer includes a torque converter; the method is characterized by achieving rapid stabilization of the scaling factor of the quartz flexible accelerometer through stabilization processing of the air gap magnetic flux density of the torque converter, the stabilization processing of the air gap magnetic flux density of the torque converter including the following steps:

[0011] S1. Determine the demagnetizing voltage X of the torque device to be processed. e ;

[0012] S2. Demagnetize and stabilize the torque generator to be processed, specifically as follows:

[0013] S2.1. Select the correct direction according to the magnetization polarity requirements, place multiple torque converters to be processed in the coil of the magnetizer and demagnetizer, set the magnetization voltage, and magnetize until saturation.

[0014] S2.2. According to the magnetization polarity requirements, select the opposite direction of magnetization in step S2.1, place the multiple torque converters to be processed that have been magnetized to saturation in step S2.1 into the coil drum of the magnetizer / demagnetizer, and set the demagnetization voltage to X. e Demagnetization and stabilization treatment is performed.

[0015] S2.3 Take out the multiple torque generators to be processed after the demagnetization and stabilization process is completed, and repeat steps S2.1 to S2.2 until the demagnetization and stabilization process of this batch of torque generators is completed, so as to obtain torque generators with stable air gap magnetic flux density, thereby realizing the rapid stabilization of the scale factor of quartz flexural accelerometer.

[0016] Furthermore, step S1 specifically includes the following steps:

[0017] S1.1 Prepare a sample group of torquers to be processed that is the same model as the batch of torquers to be processed; select the correct direction according to the magnetization polarity requirements, place the sample group of torquers to be processed in the coil of the magnetizer / demagnetizer, set the magnetization voltage, and magnetize until saturation; the sample group of torquers to be processed includes at least five torquer samples to be processed;

[0018] S1.2. Select the opposite direction to the magnetization in step S1.1, place the torque converter sample group that has been magnetized to saturation in step S1.1 into the coil of the demagnetizer, and set the demagnetization voltage X. e =X1, perform two demagnetizations; after each demagnetization, test the air gap magnetic flux density at multiple locations for each torque generator sample to be processed. If, after the second demagnetization, the air gap magnetic flux density at more than 90% of the corresponding locations of the multiple torque generator samples to be processed is reduced compared to after the first demagnetization, then execute S1.3; otherwise, determine the demagnetization voltage X of the torque generator to be processed. e =X1;

[0019] S1.3 Select another set of torque sample groups with the same model number as the torque generators to be processed, repeat step S1.1, and then select the opposite direction of magnetization in step S1.1. Place the magnetized torque sample group to be processed, which has been saturated, into the coil of the demagnetizing machine. Increase the demagnetizing voltage to X for the mth time. e =X1+H1+……H m m is an integer greater than or equal to 1, and demagnetization is performed twice. H m The demagnetizing voltage increment for the m-th demagnetizing step gradually decreases with increasing m. After each demagnetization, the air gap magnetic flux density at multiple locations for each torque generator sample is tested. If, after the second demagnetization, the air gap magnetic flux density at more than 90% of the corresponding locations of the multiple torque generator samples after the first demagnetization is reduced, this step is repeated; otherwise, the demagnetizing voltage X of the torque generator is determined. e =X1+H1+……H m.

[0020] Furthermore, in S1.1, the torque sample group to be processed includes five torque samples to be processed.

[0021] Furthermore, in S1.2, the demagnetizing voltage X is set. e =X1, where X1 is 3%-5% of the magnetizing voltage, and demagnetization is performed twice; after each demagnetization, the air gap magnetic flux density of each torque generator sample is tested at three locations uniformly selected along the circumference.

[0022] Furthermore, in S1.3, H m The value of the demagnetization voltage increase for the mth time is gradually reduced as m increases, with the reduction amount being 20%-30% of the previous time. After each demagnetization, the air gap magnetic flux density of each torque generator sample is tested at three locations uniformly selected along the circumference.

[0023] The beneficial effects of this invention are:

[0024] 1. This invention addresses key factors affecting the long-term repeatability of the scale factor in quartz flexural accelerometers, providing a method for rapidly stabilizing the scale factor. This method can quickly attenuate unstable magnetic domains within the samarium cobalt magnet of the torque converter, obtaining a torque converter with stable air gap magnetic flux density, thereby achieving rapid stabilization of the scale factor of the quartz flexural accelerometer. Furthermore, this invention utilizes a determined demagnetizing voltage X of the torque converter to be processed. e The demagnetization and stabilization process for the torque converter does not require a long time or a lot of equipment, is quick, efficient, and reduces the difficulty of operation.

[0025] 2. This invention, by conducting experiments using a sample group of torquers of the same model and batch as the torquers to be processed, can quickly determine the optimal demagnetizing voltage for the torquers. For torquers using the same samarium cobalt magnet, as long as the magnet type or manufacturer remains unchanged, the optimal demagnetizing voltage does not need to be altered, thus achieving stable and controllable production conditions. Furthermore, the H in this invention... m The increase in demagnetizing voltage for the m-th time, which gradually decreases as m increases, ensures H m The optimal demagnetizing voltage will not be deviated due to the selection of an excessively large value, and the effect of accurately determining the optimal demagnetizing voltage can be achieved. Attached Figure Description

[0026] Figure 1 This is a flowchart of the method for rapidly stabilizing the scaling factor of a quartz flexible accelerometer according to the present invention;

[0027] Figure 2 This is a schematic diagram of the torque converter. Detailed Implementation

[0028] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0029] like Figure 1 As shown, this invention provides a method for rapidly stabilizing the scaling factor of a quartz flexible accelerometer, based on key factors affecting the long-term repeatability of the scaling factor. The quartz flexible accelerometer includes a torque converter. Rapid stabilization of the scaling factor is achieved by stabilizing the air gap magnetic flux density of the torque converter. The stabilization process for the air gap magnetic flux density of the torque converter includes the following steps:

[0030] S1. Determine the optimal demagnetizing voltage X for the torque generator to be processed. e V, where X e This refers to the voltage value, where V is the unit of voltage. Specifically:

[0031] S1.1 Prepare a sample group of torquers to be processed that is the same model as the batch of torquers to be processed; select the correct direction according to the magnetization polarity requirements, place the sample group of torquers to be processed in the coil of the magnetizer / demagnetizer, set the magnetization voltage, click the start button, and magnetize the sample group of torquers to be processed until saturation; wherein, the sample group of torquers to be processed includes at least five torquers to be processed, and in this embodiment, the sample group of torquers to be processed includes five torquers to be processed;

[0032] S1.2. Select the opposite direction to the magnetization in step S1.1, place the torque converter sample group that has been magnetized to saturation in step S1.1 into the coil of the demagnetizer, and set the demagnetization voltage X. e =X1V, perform two demagnetizations, where X1 is a small value, representing 3%-5% of the magnetization voltage. After each demagnetization, test the air gap magnetic flux density at three uniformly selected positions along the circumference of each torque generator sample. If, after the second demagnetization, the air gap magnetic flux density at more than 90% of the corresponding positions of multiple torque generator samples decreased compared to the first demagnetization, then execute S1.3; otherwise, determine the optimal demagnetization voltage X for the torque generator. e =X1;

[0033] S1.3 Select another set of torque sample groups with the same model number as the torque generators to be processed, repeat step S1.1, and then select the opposite direction of magnetization in step S1.1. Place the magnetized torque sample group into the coil of the demagnetizing machine, and increase the demagnetizing voltage to X for the first time. e= (X1+H1)V, perform two demagnetizations; after each demagnetization, test the air gap magnetic flux density at three uniformly selected positions along the circumference of each torque generator sample. If, after the second demagnetization, the air gap magnetic flux density at more than 90% of the corresponding positions of multiple torque generator samples decreased compared to the first demagnetization, repeat the above steps; until the m-th time, increase the demagnetization voltage to X. e = (X1 + H1 + ... + H) m V, m are integers greater than or equal to 1, and demagnetization is performed twice. m Let X be the increase in demagnetizing voltage for the m-th time, gradually decreasing as m increases, with the decrease being 20%-30% of the previous value. After each demagnetization, the air gap magnetic flux density is tested at three uniformly selected positions along the circumference of each torque generator sample. After the second demagnetization, the air gap magnetic flux density at more than 90% of the corresponding positions of multiple torque generator samples remains unchanged compared to the first demagnetization. Then, the optimal demagnetizing voltage X for the torque generator is determined. e = (X1 + H1 + ... + H) m )V.

[0034] S2. Demagnetize and stabilize the torque generator to be processed, specifically as follows:

[0035] S2.1. Select the correct direction according to the magnetization polarity requirements, place multiple torque converters to be processed in the coil of the magnetizer / demagnetizer, set the magnetization voltage, click the start button, and magnetize multiple torque converters to be processed until saturation.

[0036] S2.2. According to the magnetization polarity requirements, select the opposite direction of magnetization in step S2.1, place the multiple torque converters to be processed that have been magnetized to saturation in step S2.1 into the coil drum of the magnetizer / demagnetizer, and set the demagnetization voltage to X. e V. Click the start button to demagnetize and stabilize multiple torque converters that have been magnetized to saturation.

[0037] S2.3 Take out the multiple torque generators to be processed after the demagnetization and stabilization treatment is completed, and repeat steps S2.1 to S2.2 until the demagnetization and stabilization treatment of this batch of torque generators is completed, and obtain torque generators with stable air gap magnetic flux density. Use the torque generators with stable air gap magnetic flux density to assemble quartz flexural accelerometers, so that the scaling factor of the quartz flexural accelerometer can be stabilized quickly during use, thereby achieving good long-term repeatability accuracy.

[0038] It should be noted that when demagnetizing and stabilizing the torque converter, selecting an appropriate voltage / current, i.e., choosing an appropriate magnetic field energy for demagnetizing the torque converter, is crucial. Excessive voltage will cause the charging / demagnetizing machine to generate excessive magnetic field energy, leading to excessive reduction in the magnetic properties of the torque converter's magnets or even reversal of magnetism. Insufficient voltage will result in insufficient magnetic field energy generated by the charging / demagnetizing machine, causing the unstable magnetic domains inside the torque converter's magnets to not decay properly, thus failing to achieve rapid stabilization of the torque converter. The rapid stabilization method for the scale factor of quartz flexural accelerometers provided by this invention overcomes these problems by using a pre-determined optimal demagnetizing voltage X for the torque converter. e The magnitude of the applied reverse magnetic field (V) can be determined by determining the demagnetizing voltage. Then, the torque generator is demagnetized and stabilized, which quickly attenuates the unstable magnetic domains inside the samarium-cobalt magnet, resulting in a torque generator with stable air-gap magnetic flux density. This air-gap magnetic flux density-stabilized torque generator is then assembled into a quartz flexural accelerometer, enabling rapid stabilization of the scale factor during use and achieving good long-term repeatability accuracy. Statistical comparisons show that compared to quartz flexural accelerometers without this torque generator stabilization method, those using this method exhibit a long-term scale factor repeatability accuracy better than 5.0 × 10⁻⁶. -5 The proportion increased by approximately 30%.

[0039] 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 changes or substitutions within the technical scope disclosed in the present invention should be covered 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 method for rapidly stabilizing the scale factor of a quartz flexible accelerometer, wherein the quartz flexible accelerometer includes a torque converter; characterized in that, The scaling factor of the quartz flexural accelerometer is rapidly stabilized by stabilizing the air gap magnetic flux density of the torque converter. The stabilization process for the air gap magnetic flux density of the torque converter includes the following steps: S1. Determine the demagnetizing voltage X of the torque device to be processed. e ; Specifically, the following steps are included: S1.1 Prepare a sample group of torquers to be processed that is the same model as the batch of torquers to be processed; select the correct direction according to the magnetization polarity requirements, place the sample group of torquers to be processed in the coil of the magnetizer / demagnetizer, set the magnetization voltage, and magnetize until saturation; the sample group of torquers to be processed includes at least five torquer samples to be processed; S1.

2. Select the opposite direction to the magnetization in step S1.1, place the torque converter sample group that has been magnetized to saturation in step S1.1 into the coil of the demagnetizer, and set the demagnetization voltage X. e = X1, where X1 is 3%-5% of the magnetization voltage, and demagnetization is performed twice. After each demagnetization, the air gap magnetic flux density of each torque generator sample is tested at three locations uniformly selected along the circumference. If the air gap magnetic flux density of more than 90% of the corresponding locations of multiple torque generator samples after the second demagnetization is reduced compared to the first demagnetization, then S1.3 is executed; otherwise, the demagnetization voltage X of the torque generator is determined. e = X1; S1.3 Select another set of torque sample groups with the same model number as the torque generators to be processed, repeat step S1.1, and then select the opposite direction of magnetization in step S1.

1. Place the magnetized torque sample group to be processed, which has been saturated, into the coil of the demagnetizing machine. Increase the demagnetizing voltage to X for the mth time. e =X1+H1+……H m m is an integer greater than or equal to 1, and demagnetization is performed twice. H m The demagnetizing voltage increment for the m-th demagnetizing test gradually decreases with increasing m, with the decrease being 20%-30% of the previous increment. After each demagnetization, the air gap magnetic flux density is tested at three uniformly selected positions along the circumference of each torque generator sample. If, after the second demagnetization, the air gap magnetic flux density is reduced at more than 90% of the corresponding positions across multiple torque generator samples compared to the first demagnetization, this step is repeated; otherwise, the demagnetizing voltage X of the torque generator is determined. e =X1+H1+……H m ; S2. Demagnetize and stabilize the torque generator to be processed, specifically as follows: S2.

1. Select the correct direction according to the magnetization polarity requirements, place multiple torque converters to be processed in the coil of the magnetizer and demagnetizer, set the magnetization voltage, and magnetize until saturation. S2.

2. According to the magnetization polarity requirements, select the opposite direction of magnetization in step S2.1, place the multiple torque converters to be processed that have been magnetized to saturation in step S2.1 into the coil drum of the magnetizer / demagnetizer, and set the demagnetization voltage to X. e Demagnetization and stabilization treatment is performed. S2.3 Take out the multiple torque generators to be processed after the demagnetization and stabilization process is completed, and repeat steps S2.1 to S2.2 until the demagnetization and stabilization process of this batch of torque generators is completed, so as to obtain torque generators with stable air gap magnetic flux density, thereby realizing the rapid stabilization of the scaling factor of quartz flexural accelerometer.

2. The method for rapid stabilization of the scale factor of a quartz flexible accelerometer according to claim 1, characterized in that: In S1.1, the torque sample group to be processed includes five torque samples to be processed.

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