A composite damping control device and method for unmanned aerial vehicle laser gyro inertial navigation

Abstract

The present application relates to unmanned aerial vehicle composite damping technical field, especially in kind for unmanned aerial vehicle laser gyro inertial navigation composite damping control device and method, the device includes unmanned aerial vehicle body connection base, anisotropic flexible isolation layer, piezoelectric shunt damping layer, active inertia compensation layer, multi-source perception layer and digital signal processing control unit, the anisotropic flexible isolation layer, piezoelectric shunt damping layer, active inertia compensation layer, multi-source perception layer and digital signal processing control unit cooperate and realize high-frequency passive energy consumption, intermediate frequency piezoelectric shunt damping, low-frequency main sensitive direction active inertia compensation and gyro error feedback correction.Different from the existing unmanned aerial vehicle damping technology, the present application will reduce the mechanical vibration amplitude optimization to reduce the actual measurement error of laser gyro, improve the stability of unmanned aerial vehicle laser gyro inertial navigation.

Description

Technical Field

[0001] This invention relates to the field of composite vibration reduction technology for unmanned aerial vehicles (UAVs), and more particularly to a composite vibration reduction control device and method for UAV laser gyroscope inertial navigation. Background Technology

[0002] In recent years, lightweight laser gyroscope strapdown inertial navigation systems have gradually replaced traditional mechanical gyroscopes and become the core navigation and attitude measurement unit for various medium- and high-altitude and tactical unmanned aerial vehicle (UAV) platforms due to their significant advantages such as fast start-up and high accuracy. However, laser gyroscopes are extremely sensitive to their mechanical environment. In actual flight, UAVs are affected by the coupling effects of complex factors such as high-speed rotation of rotor motors, aerodynamic surface disturbances, and large-scale maneuvering of the airframe, which can generate strong airframe chatter covering a wide frequency band (typically including 0~500Hz or even higher).

[0003] This harsh dynamic vibration environment severely impacts the measurement accuracy of lightweight laser gyroscopes. From a physical perspective, to overcome the lock-up effect at low speeds, the laser gyroscope must rely on a sophisticated electromechanical jittering and frequency-biasing mechanism to maintain alternating vibration. When low-frequency broadband jittering and multi-degree-of-freedom coupled angular vibrations generated by the UAV body penetrate the damping layer and directly act on the laser gyroscope, they severely interfere with the gyroscope's original pure frequency-biasing jittering state. This physical-level interference between external mechanical vibration and the internal opto-electromechanical system not only induces irreversible conic and paddle effect errors in navigation calculations but also leads to a deterioration in the gyroscope's zero-bias stability during motion and rapid divergence of measurement data.

[0004] Therefore, there is a need for composite vibration reduction control devices and methods for UAV laser gyroscope inertial navigation that can adapt to the stringent space and weight constraints of UAVs and achieve complete decoupling over a wide bandwidth. Summary of the Invention

[0005] To address the aforementioned technical problems, this invention proposes a composite vibration reduction control device and method for UAV laser gyroscope inertial navigation. By constructing a composite vibration reduction control system that combines high-frequency passive energy dissipation, mid-frequency piezoelectric shunt damping, low-frequency active inertial compensation, and laser gyroscope output error feedback correction, effective isolation, vibration decoupling, and error suppression are achieved between the complex vibration environment of the UAV and the sensitive components of the laser gyroscope.

[0006] In a first aspect, the present invention provides a composite vibration reduction control device for laser gyroscope inertial navigation in unmanned aerial vehicles, comprising: The drone body is connected to the base, which rigidly connects to the drone body. An anisotropic flexible isolation layer is disposed on the UAV body connection base, including anisotropic flexible support beam, viscoelastic damping interlayer, limiting frame and replaceable damping pads. The UAV body connection base is used for primary attenuation of high-frequency random vibration and structurally transmitted vibration. A piezoelectric shunt damping layer is disposed on the anisotropic flexible isolation layer, including a piezoelectric ceramic sheet and an adjustable impedance shunt circuit. The piezoelectric shunt damping layer is attached to the high strain region to convert the mid-frequency structural vibration energy into electrical energy and dissipate it, thereby realizing electromechanical coupling damping. An active inertial compensation layer, disposed on the piezoelectric shunt damping layer, includes at least one piezoelectric inertial actuation unit, an inertial mass block, a flexible guiding mechanism, and a power drive module; the piezoelectric inertial actuation unit is used to generate an equivalent inertial control force that is opposite to the low-frequency residual vibration; The multi-source sensing layer includes a piezoelectric vibration sensor, an accelerometer, a temperature sensor, a rotational speed synchronization input interface, and a laser gyroscope output error monitoring interface. The multi-source sensing layer is used to collect multi-source vibration and error signals. The digital signal processing and control unit is electrically connected to the piezoelectric shunt damping layer, the active inertial compensation layer, and the multi-source sensing layer, respectively. The digital signal processing and control unit receives the signal from the multi-source sensing layer and controls the impedance adjustment of the piezoelectric shunt damping layer in the mid-frequency band and the active compensation force output of the active inertial compensation layer in the low-frequency band according to the frequency band layered composite control strategy, thereby reducing the output error of the laser gyroscope. A payload platform is positioned above the multi-source sensing layer, and a support is provided on the payload platform to support the laser gyroscope body.

[0007] Optionally, the rotational speed synchronization input interface in the multi-source sensing layer is used to acquire the rotational speed of the UAV rotor motor, the commutation signal of the electronic speed controller, or the rotational speed estimate output by the flight control system; the digital signal processing control unit is used to calculate the rotor fundamental frequency and the set of major order frequencies, which are used to realize vibration order tracking and low-frequency active compensation.

[0008] Optionally, the digital signal processing control unit includes a vibration error evaluation module. The vibration error evaluation module constructs a comprehensive error index based on the root mean square value of the load platform vibration, the target order amplitude, the short-time fluctuation of the laser gyroscope zero bias, the angular velocity output noise power, and the error residual after temperature compensation. The comprehensive error index is used to adaptively adjust the piezoelectric shunt impedance parameters, active compensation gain, and phase compensation amount.

[0009] Optionally, the digital signal processing control unit monitors the driving voltage, current, displacement estimate, and power amplifier temperature of the piezoelectric inertial actuation unit in real time. When the monitored data exceeds the safety threshold, soft limiting is performed. The soft limiting is the active inertial compensation layer exiting the active compensation mode and retaining only the passive energy dissipation and semi-active damping functions.

[0010] Optionally, the piezoelectric inertial actuation unit drives the inertial mass block to generate displacement based on the inverse piezoelectric effect, and its reaction force acts directly on the load platform.

[0011] Optionally, the piezoelectric inertial actuation unit is arranged as a single-channel inertial actuation unit or a dual-channel inertial actuation unit along the main sensitive coupling direction or the equivalent main vibration direction where the laser gyroscope output error has the greatest impact.

[0012] In a second aspect, the present invention also provides a composite vibration reduction control method for UAV laser gyroscope inertial navigation, applied to the aforementioned composite vibration reduction control device, comprising the following steps: S1 synchronously collects vibration signals of the load platform, rotor speed signals, and laser gyroscope output error signals through a multi-source sensing layer. After conditioning, filtering, and analog-to-digital conversion, it forms a discrete vibration observation sequence and error data. S2, the digital signal processing and control unit calculates the rotor fundamental frequency and main order frequency set based on the rotor speed signal, and performs spectrum analysis and order tracking on the vibration observation sequence to extract the amplitude and phase information corresponding to each order frequency; S3, according to the frequency band division rules, divides the vibration signal into high frequency band, mid frequency band and low frequency band: for high frequency band vibration, only the anisotropic flexible isolation layer passively dissipates energy; for mid frequency band vibration, the equivalent impedance of the piezoelectric shunt damping layer is adjusted to enhance electromechanical coupling damping; for low frequency band rotor order vibration and residual vibration, active inertial compensation is performed through the active inertial compensation layer. S4. In active inertial compensation, an error signal is generated by comparing the desired low vibration state with the measured vibration feedback. An adaptive notch filter bank is constructed based on the ordered frequency to selectively extract and smooth the error signal. S5 performs phase lead compensation on the error signal extracted in S4 to obtain the error residual. A comprehensive error index is constructed based on the root mean square value of the load platform vibration, the target order amplitude, the short-time fluctuation of the laser gyroscope zero bias, the angular velocity output noise power, and the error residual after temperature compensation. S6 generates a digital control quantity for the controller based on the comprehensive error index. After digital-to-analog conversion and power amplification, the digital control quantity drives the piezoelectric inertial actuator to generate an equivalent inertial reaction force, thereby reducing the output error of the laser gyroscope.

[0013] Optionally, in S5, the phase advance compensation satisfies: compensation phase φ_c(n) = φ_k(n) + π - φ_a(n), where φ_k(n) is the estimated phase of the target order vibration, and φ_a(n) is the actuator link phase lag.

[0014] Optionally, in S4, the control objective of active inertia compensation is to minimize the comprehensive error index of the laser gyroscope output error while satisfying the constraints of the piezoelectric actuator's maximum voltage, displacement, temperature rise, and gyroscope mounting stress.

[0015] Optionally, when the composite vibration control device is in a power-off or standby state, the anisotropic flexible isolation layer and the piezoelectric shunt damping layer provide full vibration control.

[0016] The application of the technical solution of the present invention has at least the following beneficial effects: This invention provides a composite vibration reduction control device and method for UAV laser gyroscope inertial navigation. The device employs an anisotropic flexible isolation layer for static load support and high-frequency vibration isolation. Primary decoupling of the vibration transmission path is achieved through a flexible support beam, a viscoelastic damping interlayer, and a lightweight limiting structure. A piezoelectric shunt damping unit is introduced in the mid-frequency band to convert structural vibration energy into electrical energy via the piezoelectric effect, which is then dissipated through an adjustable impedance network, thereby improving the system's equivalent damping. In the low-frequency band, a miniature piezoelectric inertial actuation unit is used to generate an equivalent reverse inertial force only in the main coupling direction, where the laser gyroscope error is sensitive. Regarding the control method, this invention introduces rotor order tracking, adaptive notch filtering, phase compensation, and a laser gyroscope output error evaluation mechanism. The controller not only collects vibration signals from the load platform but also simultaneously acquires UAV rotor speed information and laser gyroscope output error signals. It extracts the rotor's fundamental frequency, harmonics, and main order vibration components in real time and generates a comprehensive error index based on gyroscope zero-bias fluctuations, angular velocity noise, and residual vibration state, thereby reducing the laser gyroscope output error. Compared to existing drone laser gyroscope vibration reduction technology, this invention does not reduce the amplitude of mechanical vibration, but rather reduces the actual measurement error of the laser gyroscope by controlling the vibration reduction process. Attached Figure Description

[0017] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on the structures shown in these drawings without creative effort.

[0018] Figure 1 This is a schematic diagram of the composite vibration reduction control device in a preferred embodiment of the present invention; 1-UAV body connection base; 2-Anisotropic flexible isolation layer; 3-Piezoelectric shunt damping layer; 4-Active inertial compensation layer; 5-Multi-source sensing layer; 6-Digital signal processing and control unit; 7-Payment platform; 8-Bracket; 9-Laser gyroscope body; 10-Sensor. Detailed Implementation

[0019] 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 the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the scope of protection of the present invention.

[0020] Example: like Figure 1 As shown, this embodiment provides a composite vibration reduction control device for UAV laser gyroscope inertial navigation, comprising: The UAV body connection base 1 is rigidly connected to the UAV body; the UAV body connection base 1 serves as the input end for rotor vibration, body elastic vibration and flight impact load; An anisotropic flexible isolation layer 2 is disposed on the UAV body connection base 1, including anisotropic flexible support beam, viscoelastic damping interlayer, limiting frame, and replaceable damping pads. The UAV body connection base 1 is used for primary attenuation of high-frequency random vibration and structurally transmitted vibration. In this embodiment, the anisotropic flexible isolation layer 2 is disposed above the UAV body connection base 1. The anisotropic flexible support beam, viscoelastic damping interlayer, limiting frame, and replaceable damping pads work together to achieve the installation stiffness and attitude stability of the laser gyroscope while providing primary attenuation of high-frequency random vibration and local structurally transmitted vibration. A piezoelectric shunt damping layer 3 is disposed on the anisotropic flexible isolation layer 2, including a piezoelectric ceramic sheet and an adjustable impedance shunt circuit. The piezoelectric shunt damping layer 3 is attached to the local high strain region of the anisotropic flexible support beam or load platform 7, and is used to convert the mid-frequency structural vibration energy into electrical energy and dissipate it, thereby realizing electromechanical coupling damping. In this embodiment, the piezoelectric shunt damping layer 3 is disposed above the anisotropic flexible isolation layer 2. An active inertial compensation layer 4 is disposed on the piezoelectric shunt damping layer 3, and includes at least one piezoelectric inertial actuation unit, an inertial mass block, a flexible guiding mechanism, and a power drive module; the piezoelectric inertial actuation unit is used to generate an equivalent inertial control force that is opposite to the low-frequency residual vibration; The multi-source sensing layer 5 includes multiple sensors 10, a rotational speed synchronization input interface, and a laser gyroscope output error monitoring interface. In this embodiment, the sensors include at least a piezoelectric vibration sensor, an accelerometer, and a temperature sensor. The multi-source sensing layer 5 is used to collect multi-source vibration and error signals. The digital signal processing control unit 6 is electrically connected to the piezoelectric shunt damping layer 3, the active inertial compensation layer 4, and the multi-source sensing layer 5, respectively. The digital signal processing control unit 6 receives the signal from the multi-source sensing layer 5 and controls the impedance adjustment of the piezoelectric shunt damping layer 3 in the mid-frequency band and the active compensation force output of the active inertial compensation layer 4 in the low-frequency band according to the frequency band layered composite control strategy, thereby reducing the output error of the laser gyroscope. The load platform 7 is disposed above the multi-source sensing layer 5, and the load platform 7 is provided with a bracket 8, which is used to support the laser gyroscope body 9.

[0021] Furthermore, during operation of the device in this embodiment, the piezoelectric ceramic sheet generates charge output under the slight bending or tensile / compressive strain caused by structural vibration. The generated electrical energy is dissipated or phase-adjusted through adjustable resistors, inductors, capacitors, or simulated electronic impedance networks, thereby converting the mid-frequency structural vibration energy into electrical energy and consuming it in the external circuit. The piezoelectric shunt damping layer 3 mainly undertakes the semi-active energy dissipation task of mid-frequency vibration. Its working mode is different from the active piezoelectric actuation mode that directly applies forced reverse displacement to the load platform. Instead, it changes the equivalent damping of the structure and the local energy dissipation path through electromechanical coupling damping adjustment, so as to reduce the dependence of active control on high-voltage power amplifiers and reduce the risk of secondary excitation.

[0022] Furthermore, in this embodiment, the active inertial compensation layer 4 does not employ a structure with independent piezoelectric actuators arranged along the three orthogonal directions of X, Y, and Z. Instead, based on the vibration error model of the laser gyroscope's sensitive axis, single-channel or dual-channel inertial actuation units are arranged only in the main sensitive coupling direction or equivalent main vibration direction, which has the greatest impact on the gyroscope's output error. When the controller drives the piezoelectric inertial actuation unit, the piezoelectric element drives the miniature inertial mass to generate a small, high-speed reciprocating motion. The reaction force of the inertial mass forms an equivalent control force on the load platform, which is used to counteract the low-frequency residual vibration components. Since this active compensation force originates from the relative motion of the inertial mass, its actuation unit does not need to directly clamp or press against the laser gyroscope housing, thereby avoiding additional assembly stress and structural coupling errors on the gyroscope mounting surface.

[0023] It should be noted that the piezoelectric inertial actuation unit drives the inertial mass block to generate displacement based on the inverse piezoelectric effect, and its reaction force acts directly on the load platform. Furthermore, the piezoelectric inertial actuation unit does not directly contact the laser gyroscope housing.

[0024] Furthermore, in this embodiment, the piezoelectric vibration sensor is used to collect the local high-frequency dynamic response of the load platform; the accelerometer is used to measure the low-frequency and mid-frequency vibration states at the gyroscope mounting base; the speed synchronization input interface is used to acquire the speed of the UAV rotor motor, the commutation signal of the electronic speed controller, or the speed estimate output by the flight control system; the temperature sensor is used to compensate for parameter drift caused by temperature changes in piezoelectric materials, damping materials, and the zero bias of the laser gyroscope; and the laser gyroscope output error monitoring interface is used to collect the zero bias fluctuation, periodic error, random noise enhancement, and vibration-related error characteristics in the gyroscope angular velocity output. The above multi-source information is converted by a signal conditioning circuit, a charge amplifier, an anti-aliasing filter, and a high-speed analog-to-digital converter before being input to the controller to form a unified vibration error sensing data sequence.

[0025] Furthermore, the digital signal processing control unit is used to calculate the rotor fundamental frequency and the set of major order frequencies, which are used to achieve vibration order tracking and low-frequency active compensation.

[0026] In this embodiment, the digital signal processing control unit includes a vibration error evaluation module. The vibration error evaluation module constructs a comprehensive error index based on the root mean square value of the load platform vibration, the target order amplitude, the short-time fluctuation of the laser gyroscope zero bias, the angular velocity output noise power, and the error residual after temperature compensation. The comprehensive error index is used to adaptively adjust the piezoelectric shunt impedance parameters, active compensation gain, and phase compensation amount.

[0027] Furthermore, the digital signal processing control unit monitors the driving voltage, current, displacement estimate, and power amplifier temperature of the piezoelectric inertial actuation unit in real time. When the monitored data exceeds the safety threshold, soft limiting is executed. The soft limiting is the active inertial compensation layer 4 exiting the active compensation mode and retaining only the passive energy dissipation and semi-active damping functions.

[0028] In this embodiment, the digital signal processing control unit can be a controller. During operation, the controller first preprocesses the acquired vibration error sensing data sequence. The raw signals output by the piezoelectric sensor and accelerometer are amplified by hardware charge, amplified by instruments, and subjected to anti-aliasing low-pass filtering. Then, an analog-to-digital converter continuously samples these signals at a fixed sampling period to obtain the vibration observation sequence Y(n) at the current discrete moment. Simultaneously, the controller reads the rotor speed synchronization signal, calculates the current rotor fundamental frequency f_r, and derives the set of main order frequencies Ω = {f_r, 2f_r, 3f_r, ..., kf_r} based on the number of blades and the motor's operating state. Subsequently, the digital signal processing control unit performs sliding window spectrum analysis, order tracking, and phase estimation on the vibration observation sequence Y(n), extracting the amplitude A_k(n), phase φ_k(n), and energy change rate dA_k(n) / dn corresponding to each order frequency to determine whether the current vibration source is rotor periodic excitation, structural resonance amplification, or random broadband disturbance.

[0029] After completing the vibration state identification, the controller divides the vibration signal into high-frequency, mid-frequency, and low-frequency bands according to the frequency band division rules. For high-frequency random vibration, the device mainly relies on the anisotropic flexible isolation layer 2 and the viscoelastic damping interlayer for physical energy dissipation, without activating high-gain active control to avoid the controller from making false responses to high-frequency noise. For mid-frequency structural coupling vibration, the controller adjusts the equivalent resistance, inductance, or synthetic impedance of the piezoelectric shunt damping layer 3 to form a large electromechanical coupling damping near the target frequency band, thereby enhancing the structure's energy dissipation capability. For low-frequency rotor fundamental frequency, harmonic frequency, and residual vibration of the load platform, the controller activates the active inertial compensation algorithm, using the phase-compensated control voltage to drive the micro piezoelectric inertial actuator to generate an equivalent reverse inertial force, thereby reducing the impact of vibration in this frequency band on the laser gyroscope output error.

[0030] It should be noted that the active compensation algorithm in this embodiment does not use a fixed-parameter PID to directly control the full-band error signal, but instead adopts a digital control strategy that combines rotor order tracking, adaptive notch filtering, phase lead compensation, and amplitude limiting protection.

[0031] Specifically, the controller first uses the desired static state or desired low vibration state as a reference benchmark R(n), and performs a differential comparison between the actual vibration feedback sequence Y(n) and the reference benchmark to obtain the transient error signal E(n) = R(n) - Y(n). Then, the controller constructs an adaptive notch filter bank based on the current rotor fundamental frequency and harmonics set, selectively extracting the target order component from the error signal to obtain the target control error E_k(n). To prevent control abrupt changes caused by sensor noise and high-frequency residual components, the controller performs first-order low-pass filtering and amplitude smoothing on the target control error to obtain the effective control error signal E_f(n).

[0032] Within the digital control domain, the controller performs phase lead compensation on the effective control error signal based on the amplitude-frequency characteristics, phase-frequency characteristics, and power amplifier delay characteristics of the piezoelectric inertial actuator. Let the estimated phase of the target order vibration be φ_k(n), and the actuator link phase lag be φ_a(n). Then, the compensation phase generated by the controller satisfies φ_c(n) = φ_k(n) + π - φ_a(n), ensuring that the active inertial compensation force and the target residual vibration form an approximately antiphase relationship at the load platform. The compensated control quantity U(n) is jointly determined by the order amplitude, error signal, phase compensation amount, and actuator safety constraints. Its control objective is not simply to achieve zero platform vibration displacement, but to minimize the laser gyroscope output error index while satisfying the constraints of maximum voltage, maximum displacement, maximum temperature rise of the piezoelectric actuator, and gyroscope installation stress.

[0033] Furthermore, to improve the adaptability of the device under different flight conditions, this embodiment introduces a comprehensive error index. Comprehensive error index The controller is constructed from the root mean square value of the load platform vibration, the target order amplitude, the short-time fluctuation of the laser gyroscope zero bias, the angular velocity output noise power, and the error residual after temperature compensation. When the UAV is in different operating conditions such as hovering, constant speed flight, acceleration, turning, or rapid attitude adjustment, the controller... The controller automatically adjusts the adaptive notch filter bandwidth, piezoelectric shunt impedance parameters, active compensation gain, and phase compensation amount according to the changes, shifting the vibration reduction control objective from simply reducing the amplitude of mechanical vibration to reducing the actual output error of the laser gyroscope. In this way, even if the amplitude of some mechanical vibration components is not the maximum, but their impact on the gyroscope output error is strong, the controller can still identify them as priority targets for suppression.

[0034] Furthermore, to improve the adaptability of the device under different flight conditions, this embodiment introduces a comprehensive error index. The comprehensive error index The formula used to characterize the combined impact of residual vibration of the load platform, target order vibration, laser gyroscope output error, and temperature compensation residual on the system's operating state at the current moment is as follows: ; in, The root mean square normalized index of residual vibration of the load platform. The target order vibration amplitude normalization index, This is a normalized index for the short-time fluctuation of a laser gyroscope with zero bias. The normalized index for angular velocity output noise power. This is the normalized index of the error residual after temperature compensation; , , , , These are the corresponding weighting coefficients, which are not less than 0 and satisfy the following conditions: .

[0035] In this embodiment, the above indicators are calculated as follows: The root mean square normalized index of residual vibration of the load platform: ; in, This represents the residual vibration acceleration measured by the accelerometer at the load platform end. N To calculate the length of the sliding window, The preset load platform allows for residual vibration reference values.

[0036] Target order vibration amplitude normalization index: ; in, This represents the amplitude of the k-th target order vibration component, where the target order includes the rotor fundamental frequency, harmonics, and blade passing frequency. This represents the importance coefficient of the k-th order component, where K is the number of target orders involved in the control. This is a reference value for the target order vibration amplitude.

[0037] Normalized index of short-time fluctuation at zero bias in laser gyroscope: ; in, This outputs the angular velocity of the laser gyroscope within the sliding window. Output the average angular velocity within this window. The length of the zero-bias fluctuation evaluation window. This is the reference value for permissible short-term fluctuations with zero bias.

[0038] Angular velocity output noise power normalization index: ; in, For the laser gyroscope angular velocity output at frequency Power spectral density or discrete spectral energy at that location This is a set of frequency bands of interest related to the order vibration of UAV rotors. This is a reference value for the angular velocity output noise power.

[0039] Normalized index of error residuals after temperature compensation: ; in, This is the temperature compensation output of the laser gyroscope calculated based on the current temperature sensor output and the preset temperature compensation model. This is a reference value for temperature compensation residuals.

[0040] It should be noted that the controller in this embodiment uses the above calculation expressions to unify the mechanical vibration response, rotor order vibration, laser gyroscope output zero-bias fluctuation, angular velocity noise, and temperature drift residual into a dimensionless comprehensive error index. When the comprehensive error index is large, it indicates that the current vibration state has a strong impact on the laser gyroscope output accuracy. The controller increases the low-frequency active inertial compensation gain, appropriately narrows the control bandwidth near the center frequency of the adaptive notch filter, and enhances the suppression of the target order component. When the comprehensive error index is small, it indicates that the current gyroscope output error is within the allowable range. The controller reduces the active compensation gain and decreases the output of the piezoelectric inertial actuator to reduce power consumption and avoid overcompensation.

[0041] Specifically, the controller dynamically adjusts the adaptive notch filter bandwidth, piezoelectric shunt impedance parameter, active compensation gain, and phase compensation amount based on the comprehensive error index. The adjustment method can be expressed as follows: ; ; ; ; in, For active inertial compensation gain, For the initial active compensation gain, For adaptive notch filter bandwidth, The initial notch filter bandwidth, The equivalent shunt impedance parameters are those of the piezoelectric shunt damping layer 3. The initial shunt impedance, To add phase compensation, To preset the comprehensive error reference threshold, , , , These are the adjustment coefficients for the corresponding parameters.

[0042] To ensure the stability of the control process, this embodiment sets upper and lower limits for the active inertial compensation gain, adaptive notch filter bandwidth, equivalent shunt impedance parameters of piezoelectric shunt damping layer 3, and additional phase compensation amount.

[0043] Furthermore, the controller generates an active inertial compensation control signal based on the phase-compensated target error signal. Let the effective control error signal after target order extraction, low-pass filtering, and amplitude smoothing be... Then the digital control quantity output by the controller to the piezoelectric inertial actuator can be expressed as: ; in, To control the equivalent delay compensation amount of the link, It is based on the compensated phase and satisfies: ; in, To estimate the phase of the target order vibration, The phase lag in the piezoelectric inertial actuator and power amplifier link is due to... This represents the limiting function, used to ensure that the control quantity does not exceed the safe driving range of the piezoelectric inertial actuator.

[0044] Through digital control quantity The controller enables the piezoelectric inertial actuator to output an equivalent inertial reaction force that is out of phase and matches the amplitude of the target's low-frequency residual vibration.

[0045] In a specific implementation case, the process for using the comprehensive error index is as follows: 1) The controller synchronously samples the vibration signal of the load platform, the rotor speed signal, the laser gyroscope output signal, and the temperature signal; secondly, the controller calculates within the sliding time window. , , , , The weighted summation yields the comprehensive error index.

[0046] 2) The controller compares the comprehensive error index with the preset comprehensive error reference threshold. The comparison is performed, and the adaptive notch filter bandwidth, piezoelectric shunt impedance, active compensation gain, and phase compensation are adjusted in real time based on the comparison results.

[0047] 3) The controller generates active inertia compensation control input (digital control input) based on the updated control parameters. The active inertial compensation control quantity drives the piezoelectric inertial actuation unit through a digital-to-analog converter and a high-voltage power amplifier, while adjusting the equivalent impedance of the piezoelectric shunt damping layer 3, so that the device can preferentially suppress the vibration component that has the greatest impact on the output error of the laser gyroscope under different flight conditions.

[0048] Furthermore, the device in this embodiment can also monitor the driving voltage, driving current, estimated actuation displacement, power amplifier temperature, and load platform response status of the piezoelectric inertial actuator in real time through the controller. When the calculated control voltage exceeds the safety threshold of the piezoelectric element, the controller immediately performs soft limiting on the output voltage and reduces the active compensation gain; when the actuator temperature rise exceeds the set threshold, the vibration response is abnormally amplified, or the sensor signal is distorted, the device automatically exits the active compensation mode, while retaining the operation of the anisotropic flexible isolation layer 2 and the piezoelectric shunt damping layer 3; when the UAV is in transport, standby, or power-off state, the device enters the passive energy dissipation mode, where the flexible isolation structure and the piezoelectric shunt damping circuit jointly dissipate vibration energy, ensuring that the laser gyroscope still has basic vibration reduction capability under conditions without active power supply.

[0049] Furthermore, the digital control quantity generated by the controller is synchronously triggered by a timer, converted into a continuous analog control voltage by a digital-to-analog converter, and then amplified by a low-noise high-voltage power amplifier before being applied to the piezoelectric inertial actuation unit. The piezoelectric inertial actuation unit, based on the inverse piezoelectric effect, drives a miniature inertial mass to generate rapid micro-displacement in the main sensing direction, forming an equivalent inertial reaction force C(t) that is opposite in phase and matches the amplitude of the target order component of the low-frequency residual vibration. This reaction force acts on the laser gyroscope mounting structure through a load platform, reducing the impact of low-frequency rotor order vibration and body modal vibration on the output of the laser gyroscope's sensing axis.

[0050] In addition, this embodiment also provides a composite vibration reduction control method for UAV laser gyroscope inertial navigation, applied to the above-mentioned composite vibration reduction control device, including the following steps: S1, through the multi-source sensing layer 5, synchronously collects the vibration signal of the load platform, the rotor speed signal and the laser gyroscope output error signal, and after conditioning, filtering and analog-to-digital conversion, forms a discrete vibration observation sequence and error data; S2, the digital signal processing and control unit calculates the rotor fundamental frequency and main order frequency set based on the rotor speed signal, and performs spectrum analysis and order tracking on the vibration observation sequence to extract the amplitude and phase information corresponding to each order frequency; S3, according to the frequency band division rules, the vibration signal is divided into high frequency band, mid frequency band and low frequency band: for high frequency band vibration, only the anisotropic flexible isolation layer 2 passively dissipates energy; for mid frequency band vibration, the equivalent impedance of the piezoelectric shunt damping layer 3 is adjusted to enhance electromechanical coupling damping; for low frequency band rotor order vibration and residual vibration, active inertial compensation is performed through the active inertial compensation layer 4. S4. In active inertial compensation, an error signal is generated by comparing the desired low vibration state with the measured vibration feedback. An adaptive notch filter bank is constructed based on the ordered frequency to selectively extract and smooth the error signal. S5 performs phase lead compensation on the error signal extracted in S4 to obtain the error residual. A comprehensive error index is constructed based on the root mean square value of the load platform vibration, the target order amplitude, the short-time fluctuation of the laser gyroscope zero bias, the angular velocity output noise power, and the error residual after temperature compensation. S6 generates a digital control quantity for the controller based on the comprehensive error index. After digital-to-analog conversion and power amplification, the digital control quantity drives the piezoelectric inertial actuator to generate an equivalent inertial reaction force, thereby reducing the output error of the laser gyroscope.

[0051] The composite vibration reduction control device for UAV laser gyroscope inertial navigation proposed in this embodiment differs from traditional UAV vibration reduction technology. Traditional passive vibration reduction structures for UAVs can only rely on rubber, steel wire ropes, or elastic supports for broadband attenuation, which is difficult to actively adapt to the limitations of low-frequency rotor order fluttering of UAVs. Unlike existing technologies, this embodiment divides the vibration suppression process into four levels based on the vibration spectrum characteristics of the UAV and the coupling law of the laser gyroscope sensitive axis error: high-frequency passive energy dissipation, mid-frequency piezoelectric shunt damping, low-frequency active inertial compensation in the main sensitive direction, and gyroscope error feedback correction. Specifically, this embodiment uses an anisotropic flexible isolation layer 2 to bear static load support and high-frequency vibration isolation. The primary decoupling of the vibration transmission path is achieved through a flexible support beam, a viscoelastic damping interlayer, and a lightweight limiting structure. In the mid-frequency band, a piezoelectric shunt damping unit is introduced to convert the structural vibration energy into electrical energy through the piezoelectric effect and dissipate it through an adjustable impedance network, thereby improving the system's equivalent damping. In the low-frequency band, a micro piezoelectric inertial actuation unit is used to generate an equivalent reverse inertial force only in the main coupling direction sensitive to laser gyroscope error.

[0052] In addition, this embodiment also proposes a composite vibration reduction control method for the above-mentioned device. The method introduces rotor order tracking, adaptive notch filtering, phase compensation, and laser gyroscope output error evaluation mechanism. The controller not only collects the vibration signal of the load platform, but also simultaneously acquires the rotor speed information of the UAV and the output error signal of the laser gyroscope. It extracts the rotor fundamental frequency, harmonic frequency and main order vibration components in real time, and generates a comprehensive error index based on the gyroscope zero bias fluctuation, angular velocity noise and residual vibration state. Thus, the vibration reduction control objective is optimized from the traditional reduction of mechanical vibration amplitude to reduction of the actual measurement error of the laser gyroscope.

[0053] The above description is only a preferred embodiment of the present invention and does not limit the scope of the present invention. All equivalent structural transformations made under the inventive concept of the present invention using the contents of the present invention specification and drawings, or direct / indirect applications in other related technical fields, are included within the protection scope of the present invention.

Claims

1. A composite vibration reduction control device for laser gyroscope inertial navigation in unmanned aerial vehicles, characterized in that, include: The UAV body is connected to the base (1), which rigidly connects to the UAV body; An anisotropic flexible isolation layer (2) is provided on the UAV body connection base, including anisotropic flexible support beam, viscoelastic damping interlayer, limiting frame and replaceable damping pad. The UAV body connection base is used for primary attenuation of high frequency random vibration and structurally transmitted vibration. The piezoelectric shunt damping layer (3) is disposed on the anisotropic flexible isolation layer and includes a piezoelectric ceramic sheet and an adjustable impedance shunt circuit. The piezoelectric shunt damping layer (3) is attached to the high strain region and is used to convert the mid-frequency structural vibration energy into electrical energy and dissipate it to achieve electromechanical coupling damping. An active inertial compensation layer (4) is disposed on the piezoelectric shunt damping layer, including at least one piezoelectric inertial actuation unit, an inertial mass block, a flexible guiding mechanism and a power drive module; the piezoelectric inertial actuation unit is used to generate an equivalent inertial control force that is opposite to the low-frequency residual vibration; The multi-source sensing layer (5) includes a piezoelectric vibration sensor, an accelerometer, a temperature sensor, a rotational speed synchronization input interface, and a laser gyroscope output error monitoring interface. The multi-source sensing layer is used to collect multi-source vibration and error signals. The digital signal processing control unit (6) is electrically connected to the piezoelectric shunt damping layer, the active inertial compensation layer, and the multi-source sensing layer, respectively. The digital signal processing control unit (6) receives the signal from the multi-source sensing layer and controls the impedance adjustment of the piezoelectric shunt damping layer in the mid-frequency band and the active compensation force output of the active inertial compensation layer in the low-frequency band according to the frequency band layered composite control strategy, thereby reducing the output error of the laser gyroscope. The load platform (7) is located above the multi-source sensing layer (5). The load platform (7) is provided with a bracket (8) for supporting the laser gyroscope body (9).

2. The composite vibration reduction control device according to claim 1, characterized in that, The rotational speed synchronization input interface in the multi-source sensing layer (5) is used to obtain the rotational speed of the UAV rotor motor, the commutation signal of the electronic speed controller, or the rotational speed estimate output by the flight control system; the digital signal processing control unit is used to calculate the rotor fundamental frequency and the set of main order frequencies, and the rotor fundamental frequency and the set of main order frequencies are used to realize vibration order tracking and low-frequency active compensation.

3. The composite vibration reduction control device according to claim 1, characterized in that, The digital signal processing control unit (6) includes a vibration error evaluation module. The vibration error evaluation module constructs a comprehensive error index based on the root mean square value of the load platform vibration, the target order amplitude, the short-time fluctuation of the laser gyroscope zero bias, the angular velocity output noise power, and the error residual after temperature compensation. The comprehensive error index is used to adaptively adjust the piezoelectric shunt impedance parameters, active compensation gain, and phase compensation amount.

4. The composite vibration reduction control device according to claim 1, characterized in that, The digital signal processing control unit (6) monitors the driving voltage, current, displacement estimate and power amplifier temperature of the piezoelectric inertial actuation unit in real time. When the monitored data exceeds the safety threshold, soft limiting is performed. The soft limiting is the active inertial compensation layer exiting the active compensation mode and retaining only the passive energy consumption and semi-active damping functions.

5. The composite vibration reduction control device according to claim 1, characterized in that, The piezoelectric inertial actuation unit drives the inertial mass block to generate displacement based on the inverse piezoelectric effect, and its reaction force acts directly on the load platform.

6. The composite vibration reduction control device according to claim 1, characterized in that, The piezoelectric inertial actuation unit is arranged as a single-channel inertial actuation unit or a dual-channel inertial actuation unit along the main sensitive coupling direction or the equivalent main vibration direction where the laser gyroscope output error has the greatest impact.

7. A composite vibration reduction control method for UAV laser gyroscope inertial navigation, applied to the composite vibration reduction control device according to any one of claims 1 to 6, characterized in that, Includes the following steps: S1, through the multi-source sensing layer (5), the vibration signal of the load platform, the rotor speed signal and the output error signal of the laser gyroscope are collected synchronously. After conditioning, filtering and analog-to-digital conversion, the vibration observation sequence and error data at discrete moments are formed. S2, the digital signal processing control unit (6) calculates the rotor fundamental frequency and main order frequency set based on the rotor speed signal, and performs spectrum analysis and order tracking on the vibration observation sequence to extract the amplitude and phase information corresponding to each order frequency; S3, according to the frequency band division rules, the vibration signal is divided into high frequency band, medium frequency band and low frequency band: for high frequency band vibration, only the anisotropic flexible isolation layer (2) passively dissipates energy; for medium frequency band vibration, the equivalent impedance of the piezoelectric shunt damping layer (3) is adjusted to enhance electromechanical coupling damping; for low frequency band rotor order vibration and residual vibration, active inertial compensation is carried out through the active inertial compensation layer. S4. In active inertial compensation, an error signal is generated by comparing the desired low vibration state with the measured vibration feedback. An adaptive notch filter bank is constructed based on the ordered frequency to selectively extract and smooth the error signal. S5 performs phase lead compensation on the error signal extracted in S4 to obtain the error residual. A comprehensive error index is constructed based on the root mean square value of the load platform vibration, the target order amplitude, the short-time fluctuation of the laser gyroscope zero bias, the angular velocity output noise power, and the error residual after temperature compensation. S6 generates a digital control quantity for the controller based on the comprehensive error index. After digital-to-analog conversion and power amplification, the digital control quantity drives the piezoelectric inertial actuator to generate an equivalent inertial reaction force, thereby reducing the output error of the laser gyroscope.

8. The composite vibration reduction and control method according to claim 7, characterized in that, In S5, the phase lead compensation satisfies: compensation phase φ_c(n) = φ_k(n) + π - φ_a(n), where φ_k(n) is the estimated phase of the target order vibration, and φ_a(n) is the actuator link phase lag.

9. The composite vibration reduction and control method according to claim 7, characterized in that, In S4, the control objective of active inertial compensation is to minimize the comprehensive error index of the laser gyroscope output error while satisfying the constraints of maximum voltage, displacement, temperature rise of the piezoelectric actuator and gyroscope mounting stress.

10. The composite vibration reduction and control method according to claim 7, characterized in that, When the composite vibration control device is in a power-off or standby state, the anisotropic flexible isolation layer (2) and the piezoelectric shunt damping layer (3) provide full vibration control.

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