A method for segmented vibration control of a hemispherical resonant gyroscope

Abstract

This invention provides a segmented vibration control method for a hemispherical resonator gyroscope. It analyzes the different requirements for amplitude and orthogonal control at different operating stages of the hemispherical resonator gyroscope and designs a segmented control method. From the perspective of drive detection cycle allocation, it provides control methods for the startup and stabilization stages respectively. This method comprehensively improves the speed and accuracy of the hemispherical resonator gyroscope vibration control to a certain extent, simultaneously meeting the speed and accuracy requirements of vibration control, and providing a foundation for improving the performance of hemispherical resonator gyroscopes.

Description

Technical Field

[0001] This invention belongs to the field of hemispherical resonant gyroscope technology, and particularly relates to a segmented vibration control method for a hemispherical resonant gyroscope. Background Technology

[0002] The main components of a hemispherical resonant gyroscope are a hemispherical resonator and a plate electrode. In the operating mode, a stable four-antinode standing wave is formed on the lip of the hemispherical resonator, which includes four antinodes and four nodes. A capacitor is formed between the lip of the hemispherical resonator and the plate electrode. During the gyroscope detection cycle, the standing wave vibration is detected by the current change caused by the capacitance change. During the gyroscope driving cycle, the standing wave vibration is controlled by the electrostatic force generated by changing the voltage of the capacitor plates.

[0003] Vibration control of hemispherical resonator gyroscopes is fundamental to ensuring their stable operation and achieving high-precision angular velocity measurement. Improving the startup speed of hemispherical resonator gyroscopes requires them to establish a stable standing wave within a shorter time after power-on. Improving measurement accuracy requires maintaining the stability and precision of the standing wave mode during angular velocity measurement, necessitating controlling the amplitude of the standing wave antinodes as accurately as possible to the set value, controlling the amplitude of the wave nodes to be as close to zero as possible, and simultaneously reducing noise in the vibration control loop. Existing vibration control technologies struggle to simultaneously meet both the requirements of rapidly establishing a stable standing wave and precise amplitude and orthogonal control. Summary of the Invention

[0004] The present invention aims to solve at least one of the technical problems existing in the prior art.

[0005] This invention provides a method for segmented vibration control of a hemispherical resonant gyroscope, the method comprising:

[0006] Set the upper limit of the standard deviation e of the measurement signal fitting during the startup phase of the hemispherical resonant gyroscope. m-max The measurement signals are collected, and the minimum amount of data required to meet the upper limit of the fitting standard deviation is determined through offline data processing, thus obtaining the shortest detection period t during the start-up phase. m-min1 ;

[0007] The detection duration in the total control cycle during the startup phase is set to t. m-min1 A physical experiment was conducted on a hemispherical resonant gyroscope to measure the time T required for both amplitude and orthogonality to reach the set values. s , at time T s Set as the switching point between the startup phase and the stable phase;

[0008] Set the lower limit e of the standard deviation of the measurement signal fitting during the stable phase of the hemispherical resonant gyroscope. m-minThe measurement signals are collected, and the minimum amount of data required to meet the lower limit of the fitting standard deviation is determined through offline data processing, thus obtaining the shortest detection cycle t during the stable phase. m-min2 ;

[0009] A physical experiment was conducted on a hemispherical gyroscope to adjust the proportion of the driving period in the total control period during the stable phase, and to determine the shortest driving period t required to maintain amplitude and orthogonal stability during the stable phase. d-min ;

[0010] According to t d-min and t m-min2 Set the drive detection cycle during the stable phase;

[0011] Based on the minimum duration t of the startup phase detection cycle set. m-min1 The switching point T between the startup phase and the stable phase s The segmented vibration control of the hemispherical resonant gyroscope is completed during the drive detection cycle in the stable phase.

[0012] This invention provides a segmented vibration control method for a hemispherical resonator gyroscope. This method analyzes the different vibration control requirements of the hemispherical resonator gyroscope at different operating stages and designs a segmented vibration control approach, thereby comprehensively improving the speed and accuracy of hemispherical resonator gyroscope vibration control. Compared with existing technologies, this invention solves the technical problem that existing vibration control technologies struggle to simultaneously meet the requirements of rapidly establishing a stable standing wave and precise amplitude and orthogonal control. Attached Figure Description

[0013] The accompanying drawings, which form part of this specification, are provided to further illustrate embodiments of the invention and, together with the textual description, explain the principles of the invention. It is obvious that the drawings described below are merely some embodiments of the invention, and those skilled in the art can obtain other drawings based on these drawings without any creative effort.

[0014] Figure 1 A schematic flowchart of a segmented vibration control method for a hemispherical resonant gyroscope according to a specific embodiment of the present invention is shown;

[0015] Figure 2 A schematic diagram of the startup phase cycle allocation provided according to a specific embodiment of the present invention is shown;

[0016] Figure 3 A schematic diagram of the stable phase period allocation provided according to a specific embodiment of the present invention is shown. Detailed Implementation

[0017] It should be noted that, unless otherwise specified, the embodiments and features described in this application can be combined with each other. 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 a part of the embodiments of the present invention, and not all of them. The following description of at least one exemplary embodiment is merely illustrative and is in no way intended to limit the present invention or its application or use. 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.

[0018] It should be noted that the terminology used herein is for the purpose of describing particular embodiments only and is not intended to limit the exemplary embodiments according to this application. As used herein, the singular form is intended to include the plural form as well, unless the context clearly indicates otherwise. Furthermore, it should be understood that when the terms "comprising" and / or "including" are used in this specification, they indicate the presence of features, steps, operations, devices, components, and / or combinations thereof.

[0019] Unless otherwise specifically stated, the relative arrangement, numerical expressions, and values ​​of the components and steps described in these embodiments do not limit the scope of the invention. It should also be understood that, for ease of description, the dimensions of the various parts shown in the accompanying drawings are not drawn to actual scale. Techniques, methods, and devices known to those skilled in the art may not be discussed in detail, but where appropriate, such techniques, methods, and devices should be considered part of the specification. In all examples shown and discussed herein, any specific values ​​should be interpreted as merely exemplary and not as limitations. Therefore, other examples of exemplary embodiments may have different values.

[0020] In this field, the components of the hemispherical resonant gyroscope vibration signal on the x and y axes are:

[0021]

[0022] Where a and q are the vibration amplitudes of the antinode and node of the standing wave, respectively, θ is the azimuth angle of the standing wave, ω is the resonant frequency of the hemispherical harmonic oscillator, and t is time.

[0023] Vibration control comprises two basic loops: amplitude control at antinodes and orthogonal control at nodes. The amplitude control loop maintains the amplitude of the standing wave vibration at antinodes at the given value in the control software, while the orthogonal control loop suppresses the vibration amplitude at nodes to zero. The target values ​​of the two control loops differ, but both control the magnitude of the vibration amplitude at certain locations on the hemispherical resonator. Control is achieved through the electrostatic force between the hemispherical resonator and the plate electrode, based on the difference between the actual vibration amplitude and the given value. Therefore, within the same control phase, the same approach is used to design the amplitude control methods for antinodes and nodes.

[0024] The hemispherical resonator gyroscope operates in a time-division multiplexing mode. Given the gyroscope's display head and other control methods, the drive detection cycle allocation scheme significantly impacts vibration control. Different operating stages of the hemispherical resonator gyroscope have varying control performance requirements. Therefore, the operating stage is divided into a startup stage and a steady-state stage, and vibration control schemes are designed for each stage.

[0025] like Figure 1 As shown, a segmented vibration control method for a hemispherical resonant gyroscope is provided according to a specific embodiment of the present invention, the method comprising:

[0026] Set the upper limit of the standard deviation e of the measurement signal fitting during the startup phase of the hemispherical resonant gyroscope. m-max The measurement signals are collected, and the minimum amount of data required to meet the upper limit of the fitting standard deviation is determined through offline data processing, thus obtaining the shortest detection period t during the start-up phase. m-min1 ;

[0027] The detection duration in the total control cycle during the startup phase is set to t. m-min1 A physical experiment was conducted on a hemispherical resonant gyroscope to measure the time T required for both amplitude and orthogonality to reach the set values. s , at time T s Set as the switching point between the startup phase and the stable phase;

[0028] Set the lower limit e of the standard deviation of the measurement signal fitting during the stable phase of the hemispherical resonant gyroscope. m-min The measurement signals are collected, and the minimum amount of data required to meet the lower limit of the fitting standard deviation is determined through offline data processing, thus obtaining the shortest detection cycle t during the stable phase. m-min2 ;

[0029] A physical experiment was conducted on a hemispherical gyroscope to adjust the proportion of the driving period in the total control period during the stable phase, and to determine the shortest driving period t required to maintain amplitude and orthogonal stability during the stable phase. d-min ;

[0030] According to t d-min and t m-min2 Set the drive detection cycle during the stable phase;

[0031] Based on the minimum duration t of the startup phase detection cycle set. m-min1 The switching point T between the startup phase and the stable phase s The segmented vibration control of the hemispherical resonant gyroscope is completed during the drive detection cycle in the stable phase.

[0032] This configuration provides a segmented vibration control method for hemispherical resonator gyroscopes. By analyzing the different vibration control requirements of hemispherical resonator gyroscopes at different working stages, this method designs a segmented vibration control approach, thereby achieving the goal of comprehensively improving the speed and accuracy of hemispherical resonator gyroscope vibration control.

[0033] During the startup phase, the actual amplitude of the gyroscope deviates significantly from the set value. The control method must rapidly establish a standing wave within a short time, with less emphasis on amplitude control precision. To meet this requirement, the proportion of the drive cycle in the total cycle needs to be increased, while the proportion of the detection cycle needs to be decreased, for the following reasons.

[0034] The hemispherical gyroscope is driven by electrostatic force. The magnitude of the driving force is related to the bias voltage of the resonator and the capacitance between the electrodes and the resonator. Let the capacitance value of each capacitor be C. Since the change in capacitance is mainly caused by the vertical motion of the resonator, the overlapping area S between the plates is assumed to be constant. Let the initial gap between the lip of the resonator and the plate electrode be d0, and the potential difference applied across the capacitor be V = V0. dc +V ac =U dc +U ac cosωt, then when the harmonic oscillator produces a displacement of Δd=d1·sinωt, the potential energy E formed on the capacitor is:

[0035]

[0036] Among them, V dc V ac These are the DC bias voltage and AC voltage, respectively, U dc U ac d1 represents the amplitude of the DC bias voltage and AC voltage, respectively, d1 represents the amplitude of the resonator vibration, and ε0 represents the vacuum permittivity.

[0037] The electrostatic force F is:

[0038]

[0039] Expanding the electrostatic force using Taylor at Δd / d0 = 0, we get:

[0040]

[0041] When a frequency of 1 times the driving frequency is used, that is, when the driving voltage frequency is the same as the resonant frequency of the resonator, then The effective driving force is in phase with the vibrational speed of the harmonic oscillator. Power P drive =F·v, where v is the vibration velocity of the harmonic oscillator, and the energy injected into the harmonic oscillator by the driving force is W = P drive The lip of the hemispherical harmonic oscillator is a ring with a diameter of 20 mm and a width of less than 1.5 mm. Each capacitor plate is one-eighth the area of ​​the ring, resulting in a very low effective area for electrostatic force and a limited magnitude of electrostatic force. Therefore, the larger the proportion of the driving period to the total period, the longer the driving force application time t is for the same total time, and the higher the upper limit of energy injected into the hemispherical harmonic oscillator by electrostatic force.

[0042] During the detection cycle, the control software uses the resonant frequency obtained from the frequency-phase tracking loop to generate reference signals sinωt and cosωt. It then solves for the relevant variables Sx, Sy, Cx, and Cy using a least-squares fitting method, thus representing the measured signals x and y as:

[0043]

[0044] The least squares method solves for the fitting parameters by minimizing the square of the error between the data point and the fitted model. If the detection period is extended, the influence of detection noise can be reduced. The fitting algorithm captures the trend in the measurement signal more accurately, thereby improving the detection accuracy. The reasons are explained below.

[0045] Taking the x-channel as an example, the fitting residual is used to characterize the fitting accuracy of the measured signal. The expression for the fitting standard deviation is as follows:

[0046]

[0047] Where N is the number of data points that the control software can read within each detection cycle, and x i The measured values ​​at each point are assumed to consist of both real signal and noise. Let i represent the fitted value at each point, i = 1, 2, ..., N. Noise in the measurement signal includes thermal noise, shot noise, flicker noise, etc. Taking Gaussian noise, a common type of interference, as an example, the expression for the fitted standard deviation is... The noise terms contained in each measurement are distributed on both sides of the true value, and cancellation is more likely to occur as the amount of data N increases; moreover, increasing N increases the denominator of the fitted standard deviation, thus increasing the fitted quantity. It can better reflect the true situation of vibration signals and improve detection accuracy.

[0048] Therefore, during the startup phase of the hemispherical resonator gyroscope, by increasing the proportion of the driving cycle, more time is devoted to exciting the hemispherical resonator to establish a standing wave; the proportion of the detection cycle in the total cycle is reduced to ensure basic control accuracy.

[0049] Based on this, the present invention first sets an upper limit e of the standard deviation of the measurement signal fitting during the start-up phase of the hemispherical resonant gyroscope. m-max The measurement signals are collected, and the minimum amount of data required to meet the upper limit of the fitting standard deviation is determined through offline data processing, thus obtaining the shortest detection period t during the start-up phase. m-min1 ;

[0050] Then, set the detection duration in the total control cycle of the startup phase to t. m-min1 A physical experiment was conducted on a hemispherical resonant gyroscope to measure the time T required for both amplitude and orthogonality to reach the set values. s , at time T s Set as the switching point between the startup phase and the stable phase.

[0051] After the amplitudes of the antinodes and nodes of the hemispherical resonant gyroscope reach the set values, the control phase switches to the stable phase. In the stable phase, the gyroscope is required to maintain accurate fixed amplitude four-antinode vibration. The design of the control method focuses on improving the control accuracy of amplitude and orthogonality.

[0052] Since the deviation between the actual and target values ​​of amplitude and orthogonal control is very small, this stage requires increasing the proportion of the detection period in the total period, improving the calculation accuracy of the amplitude at antinodes and nodes, and thus improving the vibration control accuracy in this stage. Because the Q value of the hemispherical resonant gyroscope is relatively large, and its time constant is typically around 400s, the amplitude decays very slowly without external force. Therefore, the proportion of the driving period in the total period can be appropriately compressed.

[0053] Based on this, the present invention further sets the lower limit e of the standard deviation of the measurement signal fitting during the stabilization phase of the hemispherical resonant gyroscope. m-min The measurement signals are collected, and the minimum amount of data required to meet the lower limit of the fitting standard deviation is determined through offline data processing, thus obtaining the shortest detection cycle t during the stable phase. m-min2 ;

[0054] Then, a physical experiment with the hemispherical gyroscope was conducted to adjust the proportion of the driving cycle in the total control cycle of the stable phase, and to determine the shortest driving cycle t required to maintain amplitude and orthogonal stability in the stable phase. d-min ;

[0055] Finally, according to t d-min and t m-min2 Set the driver detection cycle for the stable phase; based on the minimum duration t of the set startup phase detection cycle. m-min1 The switching point T between the startup phase and the stable phase s The segmented vibration control of the hemispherical resonant gyroscope is completed during the drive detection cycle in the stable phase.

[0056] This invention proposes a segmented vibration control method for hemispherical resonant gyroscopes. It analyzes the different requirements for amplitude and orthogonal control at different operating stages of the hemispherical resonant gyroscope and designs a segmented control method. From the perspective of drive detection cycle allocation, it provides control methods for the startup and stabilization stages respectively. This method comprehensively improves the speed and accuracy of hemispherical resonant gyroscope vibration control to a certain extent, simultaneously meeting the speed and accuracy requirements of vibration control, and providing a foundation for improving the performance of hemispherical resonant gyroscopes.

[0057] To gain a further understanding of the present invention, the segmented vibration control method for hemispherical resonant gyroscopes of the present invention will be described in detail below with reference to specific embodiments.

[0058] In this embodiment, during the startup phase, the ratio of the drive cycle to the detection cycle is set to 3:1. This ratio can be adjusted according to the performance of different gyroscopes, as shown in the diagram. Figure 2 . Figure 2 In the middle, T r T c and T d These represent the duration of the switching interval between the drive and detection cycles, the duration of the detection cycle, and the duration of the drive cycle, respectively.

[0059] During the stabilization phase, the ratio of the drive cycle to the detection cycle is set to 1:3. This ratio can be adjusted according to the performance of different gyroscopes, as shown in the diagram below. Figure 3 . Figure 3 In the middle, T r T c and T d These represent the duration of the switching interval between the drive and detection cycles, the duration of the detection cycle, and the duration of the drive cycle, respectively.

[0060] Based on the aforementioned period ratio, segmented vibration control of the hemispherical resonant gyroscope is achieved.

[0061] In summary, this invention provides a segmented vibration control method for a hemispherical resonant gyroscope. By switching the drive detection cycle in segments, the start-up time of the hemispherical resonant gyroscope is shortened, the angular velocity measurement accuracy of the hemispherical resonant gyroscope is improved, and the overall performance of the hemispherical resonant gyroscope in practical application scenarios is enhanced.

[0062] The above description is merely a preferred embodiment of the present invention and is not intended to limit the invention. Various modifications and variations can be made to the present invention by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., 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 method for segmented vibration control of a hemispherical resonant gyroscope, characterized in that, The segmented vibration control method for the hemispherical resonant gyroscope includes: Set the upper limit of the standard deviation e of the measurement signal fitting during the startup phase of the hemispherical resonant gyroscope. m-max The measurement signals are collected, and the minimum amount of data required to meet the upper limit of the fitting standard deviation is determined through offline data processing, thus obtaining the shortest detection period t during the start-up phase. m-min1 ; The detection duration in the total control cycle during the startup phase is set to t. m-min1 A physical experiment was conducted on a hemispherical resonant gyroscope to measure the time T required for both amplitude and orthogonality to reach the set values. s , at time T s Set as the switching point between the startup phase and the stable phase; Set the lower limit e of the standard deviation of the measurement signal fitting during the stable phase of the hemispherical resonant gyroscope. m-min The measurement signals are collected, and the minimum amount of data required to meet the lower limit of the fitting standard deviation is determined through offline data processing, thus obtaining the shortest detection cycle t during the stable phase. m-min2 ; A physical experiment was conducted on a hemispherical gyroscope to adjust the proportion of the driving period in the total control period during the stable phase, and to determine the shortest driving period t required to maintain amplitude and orthogonal stability during the stable phase. d-min ; According to t d-min and t m-min2 Set the drive detection cycle during the stable phase; Based on the minimum duration t of the startup phase detection cycle set. m-min1 The switching point T between the startup phase and the stable phase s The segmented vibration control of the hemispherical resonant gyroscope is completed during the drive detection cycle in the stable phase.

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