A mine-used intrinsic safety type inertial navigation measuring device and system based on a resonant gyro technology

Abstract

The application provides a mine-used intrinsic safety type inertial navigation measuring device and system based on a resonant gyro technology, and relates to the field of inertial navigation.The measuring device comprises an intrinsic safety sensing unit and a signal processing unit, wherein the intrinsic safety sensing unit comprises a resonant gyro and a high-voltage excitation application specific integrated circuit;the processing unit is output to an upper computer after inertial navigation calculation processing;the intrinsic safety sensing unit is arranged in a closed vacuum shield;and the intrinsic safety sensing unit and the signal processing unit are connected through an intrinsic safety cable.The application chips the application specific integrated circuit with a high-voltage generation function, and arranges the application specific integrated circuit and the resonant gyro in a vacuum cavity, so as to physically limit the size and energy storage of the high-voltage circuit, make the inherent energy lower than the ignition limit, and realize true intrinsic safety.

Description

Technical Field

[0001] This invention relates to the field of inertial navigation, and more particularly to an intrinsically safe inertial navigation measurement device and system for mining operations based on resonant gyroscope technology. Background Technology

[0002] Resonant gyroscopes, especially fused silica hemispherical resonant gyroscopes (HRGs), play a crucial role in inertial navigation systems due to their high precision, long lifespan, wear-free operation, and shock resistance. Applying them to autonomous navigation, attitude monitoring, and directional drilling in mining machinery can significantly improve automation levels and production safety.

[0003] However, the presence of flammable gases such as methane and coal dust in underground mines necessitates that all electrical equipment meet intrinsically safe explosion-proof standards (such as GB 3836.4-2010, published on August 9, 2010). The core of this standard is to limit the energy of electrical sparks generated by circuits under any normal or fault condition, ensuring that they are insufficient to ignite specific hazardous gases (for example, the minimum ignition energy of methane, a Class IIC gas, is approximately 200 μJ).

[0004] For metal resonant gyroscopes, electromagnetic or piezoelectric excitation is typically used, resulting in lower operating voltages and making it easy to meet national standards for intrinsic safety. However, for higher-performance fused silica resonant gyroscopes (HRGs), their operating principle requires applying a high-voltage AC signal of several hundred volts to their excitation electrodes to generate sufficient electrostatic force to drive a high-Q quartz resonator. This directly leads to two fundamental conflicts with intrinsic safety certification:

[0005] 1. Voltage exceeding the limit: Intrinsic safety standards have strict upper limits on circuit voltage in hazardous locations (downhole) (usually below 30VDC / AC), which is far below the operating voltage required by HRG;

[0006] 2. Excessive Energy: Energy stored in the high-voltage power supply and its parasitic capacitance (E=½CV) 2 The energy released during a short-circuit fault is likely to exceed the minimum ignition energy.

[0007] In existing technologies, the entire high-voltage unit is placed inside an explosion-proof enclosure. This method only achieves "isolation" and carries the risk of "explosion failure" due to enclosure damage, rather than "intrinsically safe". In addition, the equipment is bulky and inconvenient to install.

[0008] Furthermore, traditional mining inertial navigation systems are based on fiber optic gyroscopes or laser gyroscopes. The smallest mining fiber optic gyroscope inertial measurement unit (IMU) measures 160*130*120mm, with the single-axis fiber optic gyroscope measuring 50mm. Additionally, IMU systems composed of fiber optic gyroscopes require calibration every three years to ensure measurement accuracy. Therefore, traditional mining IMUs suffer from low integration, weak anti-interference capabilities, high maintenance costs, and a lack of intelligent self-calibration functions.

[0009] Therefore, there is an urgent need to provide a solution for an intrinsically safe inertial measurement device and system for mining based on a resonant gyroscope. Summary of the Invention

[0010] To address the above issues, the present invention provides an intrinsically safe inertial navigation and measurement device and system for mining based on resonant gyroscope technology. Through a system architecture of "internal and external division of labor, intracavity pressure generation, energy limit control, and ASIC integration," it can not only resolve the fundamental conflict between high-voltage excitation and intrinsic safety standards, but also achieve high-precision, high-reliability, low-power consumption, and low-maintenance operation of the inertial navigation device and system.

[0011] This invention provides an intrinsically safe inertial navigation measurement device for mining based on resonant gyroscope technology. The measurement device includes an intrinsically safe sensing unit and a signal processing unit. The intrinsically safe sensing unit includes a resonant gyroscope and a high-voltage excitation dedicated integrated circuit. The high-voltage excitation dedicated integrated circuit converts the low-voltage DC power and low-voltage digital control signals output by the signal processing unit into high-voltage AC drive signals to drive the resonant gyroscope. The output signal of the resonant gyroscope is output to the processing unit. After inertial navigation calculation processing, the signal processing unit outputs the signal to a host computer. The intrinsically safe sensing unit is placed in a sealed vacuum shield. The intrinsically safe sensing unit and the signal processing unit are connected by an intrinsically safe cable.

[0012] Furthermore, the resonant gyroscope is a hemispherical resonant gyroscope, a μHRG, or a metallic resonant gyroscope.

[0013] Furthermore, the resonant gyroscope is a hemispherical resonant gyroscope, which includes a resonator and a detection base. The detection base is provided with an excitation electrode and a detection electrode. The resonator is a fused silica resonator, and the excitation electrode and the detection electrode are arranged in a ring at intervals.

[0014] Furthermore, the capacitors used inside the high-voltage excitation dedicated integrated circuit are all at the pF level, so that the maximum energy released by the circuit inside the vacuum shield under any fault condition is less than 2.61 microjoules.

[0015] Furthermore, the vacuum shield is provided with a vacuum feedthrough connector that connects to the intrinsically safe cable.

[0016] Furthermore, the bottom of the vacuum shield is potted with insulating and thermally conductive adhesive.

[0017] Furthermore, the vacuum shield is made of a high-temperature resistant material produced by 3D printing.

[0018] Furthermore, the output signal of the resonant gyroscope is conditioned by a micro preamplifier and then output to the signal processing unit through the intrinsically safe cable.

[0019] Furthermore, the high-voltage excitation dedicated integrated circuit includes: a control logic circuit for parsing the low-voltage digital control signal; a charge pump DC boost circuit for converting the low-voltage DC power into high-voltage DC power; an inverter circuit for converting the high-voltage DC power into high-voltage AC power; and a feedback control circuit that precisely controls the amplitude of the high-voltage AC power by adjusting the output voltage of the charge pump to generate a high-voltage AC square wave signal. The low-voltage digital control signal modulates the high-voltage AC square wave and outputs a high-voltage AC square wave drive signal for driving the resonant gyroscope.

[0020] Furthermore, the high-voltage excitation dedicated integrated circuit includes the following functional modules: a signal conditioning module, supporting full-angle mode or force balance mode, used to condition the output signal of the detection electrode of the resonant gyroscope; a self-calibration control module, which uses a non-selective rotation method to realize the calibration-free operation of the resonant gyroscope system; and an intrinsically safe protection module, including overcurrent monitoring, overvoltage protection and anti-static control, which monitors the operating parameters of the measuring device in real time and triggers the protection mechanism in case of abnormality.

[0021] Furthermore, the signal processing unit includes: an intrinsically safe power supply module that outputs a low-voltage DC power supply signal; a main processor that includes a signal processing module and a digital waveform generator; the signal processing module receives the resonant gyroscope signal transmitted from the intrinsically safe sensing unit and external input signals, and outputs attitude angle data and carrier motion trajectory from the interface circuit after inertial navigation processing; the digital waveform generator outputs a low-voltage digital control signal; and an intrinsically safe barrier circuit, which is composed of a precision current-limiting resistor and a Zener / clamping diode.

[0022] Furthermore, the signal processing module can be integrated into the high-voltage excitation dedicated integrated circuit.

[0023] The present invention also provides an intrinsically safe inertial navigation measurement system for mining based on resonant gyroscope technology, the measurement system including multiple of the aforementioned inertial navigation measurement devices and multiple accelerometers.

[0024] The beneficial effects of this invention are:

[0025] 1. Fundamentally resolve the conflict between high-voltage excitation and intrinsic safety: By ASIC-izing the high-voltage generation function and embedding it in the vacuum chamber, the scale and energy storage of the high-voltage circuit are physically limited, ensuring that its inherent energy is below the ignition limit, thus achieving true intrinsic safety;

[0026] 2. High precision and high reliability: The high-voltage signal is generated and used locally within the cavity, avoiding interference during long-distance transmission and ensuring the purity and accuracy of the drive signal;

[0027] 3. High Integration and Miniaturization: The inertial navigation and measurement equipment and system based on resonant gyroscopes reduces the size by more than 30% compared to traditional mining fiber optic inertial navigation systems. Furthermore, the system uses an ASIC chip, integrating signal processing, computation, protection, and calibration-free functions, resulting in a volume reduction of over 40% and a 30% reduction in power consumption compared to traditional mining inertial navigation systems.

[0028] 4. Strong compatibility and scalability: Supports various gyroscope types such as fused silica resonant gyroscope (HRG), metal resonant gyroscope, and μHRG, adapting to different mining application scenarios;

[0029] 5. Low maintenance and high intelligence: With the help of self-calibration control and intrinsically safe protection logic, the equipment can achieve long-term low maintenance operation, eliminating the cumbersome process of recalibrating traditional inertial measurement equipment every 3 years to ensure the accuracy of measurement data, thereby effectively reducing downhole operation costs;

[0030] 6. Excellent engineering prospects: Based on mature integrated circuit and vacuum packaging technology, it is suitable for mass production and deployment in harsh mining environments. Attached Figure Description

[0031] 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.

[0032] Figure 1(a) is a three-dimensional structural diagram of a hemispherical resonant gyroscope in the prior art;

[0033] Figure 1(b) is a top view of the structure of a hemispherical resonant gyroscope in the prior art;

[0034] Figure 2 A schematic diagram of the internal structure of the intrinsically safe sensor head based on a hemispherical resonant gyroscope provided for this invention;

[0035] Figure 3 A structural block diagram of an intrinsically safe inertial navigation and measurement device for mining based on a resonant gyroscope, provided by the present invention;

[0036] Figure 4 A block diagram of the internal circuit module of the intrinsically safe high-voltage excitation ASIC provided by the present invention;

[0037] Figure 5 This invention provides an internal functional module block diagram of an intrinsically safe high-voltage excitation ASIC.

[0038] Figure 6 This is a block diagram of the inertial navigation measurement system provided by the present invention.

[0039] The realization of the objective, functional features and advantages of the present invention will be further explained in conjunction with the embodiments and with reference to the accompanying drawings. Detailed Implementation

[0040] Exemplary embodiments will now be described in detail, examples of which are illustrated in the accompanying drawings. When the following description relates to the drawings, unless otherwise indicated, the same numerals in different drawings denote the same or similar elements. The embodiments described in the following exemplary embodiments do not represent all embodiments consistent with this disclosure. Rather, they are merely examples of apparatuses and methods consistent with some aspects of this disclosure as detailed in the appended claims.

[0041] The terms "first," "second," etc., used in this disclosure are for distinguishing similar objects and are not necessarily used to describe a specific order or sequence. It should be understood that such use of data can be interchanged where appropriate so that the embodiments of this disclosure described herein can be implemented, for example, in orders other than those illustrated or described herein.

[0042] Furthermore, the terms “comprising” and “having”, and any variations thereof, are intended to cover non-exclusive inclusion, such that a process, method, system, product, or apparatus that includes a series of steps or units is not necessarily limited to those steps or units that are explicitly listed, but may include other steps or units that are not explicitly listed or that are inherent to such process, method, product, or apparatus.

[0043] Multiple, including two or more. And / or, it should be understood that, for the purposes of this disclosure, the term "and / or" is merely a description of the relationship between related objects, indicating that three relationships can exist. For example, A and / or B can represent: A existing alone, A and B existing simultaneously, and B existing alone.

[0044] A hemispherical resonant gyroscope (HRG) is a type of Coriolis gyroscope characterized by ultra-high reliability (no moving parts), long lifespan, strong environmental adaptability, ultra-high precision (zero-bias stability can reach 0.0001° / h or even higher), strong shock resistance, and fast start-up (no heating time required). The working effect of the hemispherical resonant gyroscope was discovered by Bryan in 1890, and the first hemispherical resonant gyroscope was invented in the 1960s. Since the Safran Group of France achieved a breakthrough in hemispherical resonant gyroscope manufacturing technology, the application fields of hemispherical resonant gyroscope products have been greatly expanded. High-precision hemispherical resonant gyroscopes are commonly used in high-end fields such as aerospace, marine, satellite attitude control, and submarine navigation.

[0045] A hemispherical resonant gyroscope is a shell resonant gyroscope. Its core is a hemispherical resonant shell made of fused silica, which maintains vibration and reads signals through excitation and detection electrodes at the edge.

[0046] This is a schematic diagram of a hemispherical resonant gyroscope (HRG) including its internal ring-shaped excitation electrode and detection electrode structure. (See diagram:)

[0047] As shown in Figures 1(a) and 1(b), the hemispherical resonant gyroscope is mainly composed of a hemispherical resonator, an excitation cover, and a detection base. The resonator is usually made of fused silica. The excitation electrodes and detection electrodes on the detection base are arranged in a ring with a total of 16 electrodes, but other numbers are also possible.

[0048] The excitation shield drives the resonator with an electrostatic field, causing it to vibrate mechanically. When the resonator is working, a standing wave forms at its edge, exhibiting periodic undulations at the edge of a hemisphere, with four antinodes and four nodes distributed on the circumference (in this case, the n=2 mode). In a stationary state, the spatial orientation of the standing wave is fixed. When the gyroscope rotates around its axis of symmetry with an angular velocity Ω, the Coriolis effect causes a backward precession in the direction of the antinodes of the standing wave. The precession angular velocity Ω' of the standing wave is proportional to the input angular velocity.

[0049] Ω'=KΩ (1)

[0050] Where K is the precession factor of the hemispherical resonant gyroscope, which is determined by the structural geometry of the resonator; the displacement change of the resonator is read out using detection electrodes, thereby measuring the precession angle of the standing wave.

[0051] The excitation and detection electrodes are the components of the HRG that enable the two key functions of "generating standing waves" and "detecting the position of standing waves." When the gyroscope starts up, the excitation electrode forces the resonator to generate initial vibrations through electrostatic force, establishing a standing wave. During gyroscope operation, the standing wave decays due to energy loss (damping). The excitation electrode continuously applies electrostatic force to replenish the resonator's energy, keeping the standing wave amplitude constant. By precisely controlling the frequency and phase of the applied signal, the desired specific vibration mode can be excited and stabilized at its maximum amplitude. Its performance directly affects the gyroscope's startup time, power consumption, and long-term stability.

[0052] The detection electrode, in contact with ground, detects the vibration displacement of the resonator's edge, precisely measuring the azimuth angle of the standing wave pattern, i.e., the location of the antinodes. The resonator serves as the common electrode, and the detection electrode as the other electrode; together, they form a capacitor. When the resonator vibrates, the gap between it and the detection electrode changes periodically, causing a minute change in capacitance. The detection circuit (typically a preamplifier and demodulation circuit) captures this minute capacitance change and converts it into a voltage signal proportional to the vibration displacement. By analyzing the signals from the detection electrode at different positions, the precise angle of the standing wave relative to the shell can be calculated. The sensitivity and noise level of the detection electrode directly determine the gyroscope's measurement accuracy and resolution. In practical applications, the HRG primarily operates in two modes: full-angle mode and force rebalancing mode.

[0053] The excitation electrodes in HRGs typically require relatively high voltage drives, especially in macroscopic, high-precision HRGs. As previously mentioned, the excitation electrodes cause the resonator to vibrate via electrostatic force. The electrostatic force F between the two parallel plates is given by the formula:

[0054] (2)

[0055] Where: V is the voltage difference between the resonant electrode and the resonant oscillator; d is the gap distance between them; A is the relative area. It is the dielectric constant. To obtain a sufficiently large driving force, either the voltage V must be increased or the gap d must be decreased. A precise and fixed gap needs to be maintained between the resonator (hemispherical shell) and the electrode base of the HRG. This gap is typically on the order of tens to hundreds of micrometers. Too small a gap will greatly increase the manufacturing difficulty and bring reliability risks (such as electrostatic breakdown, contact short circuit, etc.); therefore, there are limits to increasing the driving force by reducing the gap. Therefore, when the gap d is fixed by the physical structure, the most effective and direct method is to increase the driving voltage V. Thus, the driving voltage of the HRG is usually in the range of tens to hundreds of volts of DC bias. However, this increases the circuit complexity, requiring the design of high voltage generation circuits (charge pumps, etc.) and high voltage driving circuits, which increases the complexity and power consumption of the system; and reliability risks: high voltage has the risk of breakdown, the insulation performance between the electrodes and the resonator is extremely high, and there is electromagnetic interference, high voltage switching or AC signals may generate EMI, requiring careful design of shielding and wiring.

[0056]

Example 1

[0057] This invention provides an intrinsically safe inertial navigation measurement device for mining. In this embodiment, an intrinsically safe inertial navigation measurement device based on a hemispherical resonant gyroscope is used.

[0058] In this embodiment, as Figure 3 The diagram shown is a structural block diagram of an intrinsically safe inertial navigation measurement device for mining based on a resonant gyroscope. The intrinsically safe inertial navigation measurement device for mining includes a physically separate intrinsically safe sensor head and a processing unit, which are connected by an intrinsically safe cable and a connector.

[0059] like Figure 2 As shown, the intrinsically safe sensor head includes: a vacuum shield containing: a resonant gyroscope core, which is a fused silica hemispherical resonator; an intrinsically safe high-voltage excitation ASIC specifically for exciting the fused silica resonant gyroscope; and a micro preamplifier (not shown in the figure, but integrated into the resonator detection electrode) for detecting the resonator's vibration signal. The vacuum shield maintains a high vacuum state, with a vacuum degree <10. -3 Pa, an insulating and thermally conductive adhesive potting area (layer) is provided at the bottom of the vacuum chamber. This insulating and thermally conductive layer covers the periphery of the resonant gyroscope detection base and the ASIC circuit, which not only provides insulation to prevent leakage but also serves as vibration isolation. The output stage of the intrinsically safe high-voltage excitation dedicated integrated circuit integrates an on-chip current-limiting resistor to limit the fault current when a short circuit occurs at the excitation electrode.

[0060] The vacuum shield, designed for underground mining operations, requires high-temperature resistant materials to withstand temperatures exceeding 125-135 degrees Celsius. SnAg and SnAgCu alloys are suitable materials. Alternatively, 3D-printed metal materials such as nickel-based high-temperature alloys, titanium alloys, aluminum alloys, and cobalt-chromium alloys can be used; 3D-printed alumina, zirconium oxide, and silicon carbide ceramics can also be employed. Compared to ordinary explosion-proof shells, the vacuum shield of this invention is lightweight. Explosion-proof shells are typically made of cast aluminum or stainless steel and are thick. This invention's vacuum shield does not rely on the mechanical strength of the outer shell for explosion protection, but rather on the inherent safety of the internal circuitry, meaning that electrical sparks and thermal effects are insufficient to ignite it. Furthermore, its compact and lightweight design allows for compatibility with inertial navigation mobile carriers (mine cars). In addition, the vacuum shield of this invention also meets the requirements for dustproofing, waterproofing, impact resistance, and vibration resistance, and the outer shell has low processing costs. In terms of maintenance and operation, it is more convenient than explosion-proof enclosures. Explosion-proof enclosures are strictly prohibited from being opened for testing while energized, while the true shielding cover of this invention is outside the hazardous area and can be opened for debugging and maintenance while energized (but safety rules must be followed) because the interior is safe. The table below provides a simple comparison:

[0061] Table 1

[0062]

[0063] Preferably, in this embodiment, the intrinsically safe sensor head is a vacuum shield (vacuum degree <10). -3 The Pa) features a resonant gyroscope core (Q value = 22E6) and an intrinsically safe high-voltage excitation ASIC (0.35μm BCD process, 6-stage charge pump, 6×4pF flying capacitor).

[0064] The intrinsically safe sensor head is designed to meet intrinsic safety standards. In this invention, "intrinsically safe" means that the electrical equipment meets the current GB intrinsically safe explosion-proof standard (GB 3836.4-2010) and can pass intrinsically safe testing.

[0065] Figure 2The processing unit described includes: an intrinsically safe power supply module that outputs a low-voltage DC power signal to power the entire system; a main processor including a signal processing module and a digital waveform generator. The signal processing module performs inertial navigation (INS) processing, receiving resonant gyroscope signals (angular velocity values) transmitted from the intrinsically safe sensor head via an intrinsically safe cable, and external input signals (including but not limited to input signals from BDS, GPS, USBL, total station, and accelerometer). After processing, it outputs attitude angle data and motion trajectory output from the interface circuit. The digital waveform generator outputs a low-voltage digital control signal; an intrinsically safe barrier circuit, which consists of a precision current-limiting resistor and a voltage regulator / clamping diode, ensuring that the voltage, current, and total power entering the danger zone under any fault condition are limited to a safe range (equivalent to the function of a fuse); the low-voltage DC power signal output by the intrinsically safe power supply and the low-voltage digital control signal output by the digital waveform generator are transmitted to the inside of the vacuum shield through a ceramic-metal vacuum feedthrough connector and sent to the intrinsically safe high-voltage excitation ASIC.

[0066] The communication interface circuit uses RS422 / 485 / 232 interfaces (these interfaces need to be set according to the interface of the connected device) to connect to the host computer (downhole monitoring system communication and / or navigation computer) to realize the transmission of equipment positioning and attitude monitoring and inertial measurement data;

[0067] The intrinsically safe power module is connected to the intrinsically safe barrier circuit and the main processor, and the main processor is connected to the communication interface circuit and the intrinsically safe barrier circuit.

[0068] In this embodiment, preferably, the intrinsically safe power supply module has an output voltage of 5V and a maximum current of 60mA, which meets the intrinsically safe "ib" level. The inertial measurement data of the resonant gyroscope is output through the standard 422 level of the communication interface circuit, and the RS485 interface is used to realize the equipment positioning and attitude monitoring of the downhole monitoring system.

[0069] Digital waveform generators (such as PWM peripherals of FPGAs or processors) generate low-voltage digital control signals, such as PWM waves or digital serial commands, to drive the resonator. Their physical levels are safe CMOS or LVDS levels (such as 3.3V).

[0070] The main processor uses an ARM Cortex-M4 to generate a 5kHz PWM signal, which is output through optocoupler isolation and intrinsic safety barrier (1kΩ current-limiting resistor + 5.1V Zener diode).

[0071] The high-voltage conversion within the vacuum chamber is achieved by ASIC circuitry, such as... Figure 4 As shown: The ASIC performs the following operations sequentially within the vacuum chamber to generate a high-voltage AC signal that ensures energy safety: specifically including the following modules:

[0072] 1. Signal Decoding and Clock Management Module: This module is responsible for parsing external PWM signals or digital instructions and converting them into digital quantities used to control the target output voltage amplitude. The process involves the ASIC's internal digital logic unit parsing the PWM duty cycle or digital instructions from the outside, thereby generating the digital quantities to control the target output voltage amplitude. Furthermore, this module also generates the synchronization timing required for the entire chip's operation based on the input clock or internal oscillator.

[0073] 2. Charge Pump DC-DC Boost Module: This module utilizes a multi-stage charge pump circuit (such as a Dickson architecture) integrated within the ASIC to initiate operation. By employing off-chip or on-chip miniature flying capacitors (with capacitance values ​​of only a few pF) and a high-speed switching network, driven by a high-frequency clock (e.g., 1MHz), the input 3.3V low-voltage DC is gradually "pumped up" to generate a stable, programmable high-voltage DC (e.g., +300V). The key to this process is that all capacitors are in the pF range, which maximizes the theoretical energy storage of the entire boost circuit. Designed to operate at microjoule levels, far below the safety threshold, it ensures that the maximum possible energy released by the high-voltage circuitry inside the vacuum shield under any fault condition is less than 2.61 microjoules.

[0074] 3. H-Bridge Power Inverter (DC-AC) Module: This module converts high-voltage direct current (DC) into a high-voltage alternating current (AC) square wave signal with a frequency matched to the natural frequency of the resonator. The ASIC integrates a full H-bridge power output stage, consisting of four high-voltage MOSFETs. The power supply of the H-bridge is directly connected to the high-voltage DC power supply generated by the charge pump. Based on the natural frequency of the resonator, the ASIC logic unit generates two complementary switching control signals with dead time, driving the two pairs of switches in the H-bridge to conduct alternately, thereby precisely inverting the high-voltage DC into a high-voltage AC square wave signal.

[0075] 4. Precision Amplitude Control Module: This module dynamically adjusts the charge pump output voltage through a closed-loop mechanism to achieve precise control of the AC square wave amplitude. The specific process is as follows: The amplitude of the output AC square wave is regulated by a closed-loop system. The ASIC dynamically adjusts the charge pump output voltage using a feedback mechanism (or directly based on external commands). Specifically, if the external input is a PWM signal, its DC component is used as the voltage reference for the charge pump after low-pass filtering; if it is a digital command, a corresponding analog reference voltage is generated through an internal DAC. Finally, this amplitude-controllable high-voltage AC square wave is directly applied to the excitation electrode of the fused silica resonator. The high-voltage AC square wave on the excitation electrode generates a strong alternating electrostatic field, driving the fused silica resonator to generate and maintain stable, high-quality standing wave oscillations at its natural frequency; the detection electrode senses the resonator's oscillation state through capacitance changes, and the signal is conditioned by a micro preamplifier and output to the processing unit for calculation.

[0076] The inertial measurement data of the hemispherical resonator gyroscope is output through a standard 422 level, which complies with the intrinsic safety certification test standards for power supply, circuit and interface.

[0077] The intrinsically safe high-voltage excitation ASIC can further integrate the following functions, see [link to relevant documentation]. Figure 5 To achieve single-chip, high anti-interference, and calibration-free control:

[0078] 1) Signal processing function: Supports multiple signal processing modes such as full-angle mode and force balance mode; drives signal generation and signal adjustment, including adjusting the filtered signal waveform and reducing noise;

[0079] In the field of navigation, "full-angle mode" is more often referred to as "posture control" or "trajectory tracking". The planning unit generates an ideal path from point A to point B. Each point on this path has a specified position and orientation (i.e., "posture"). The control unit then minimizes the error between the actual posture of the current mining truck and the target posture on the ideal path.

[0080] In the field of navigation, the "force balance model" is closer to the "potential field method" or "model predictive control." Its core idea is to treat the movement of the mine car as moving within a "force field," and to determine the direction of movement by balancing various virtual "attractive" and "repulsive forces." The target point generates "attractive forces," and obstacles generate "repulsive forces." The direction and behavior of the mine car's movement are determined by the direction of the resultant force of all the attractive and repulsive forces acting on its location.

[0081] The driving signal includes a high-voltage AC square wave signal that drives the excitation electrode of the fused silica resonator.

[0082] 2) Self-calibration control function: It uses methods such as "non-selective rotation" to compensate for gyroscope errors and achieve long-term calibration-free operation of the system;

[0083] Self-calibration technology is mainly divided into two major technical routes: rotation modulation based on mechanical motion and non-rotation methods based on information processing.

[0084] The essence of rotation modulation technology is to change the relative attitude of the inertial measurement unit (IMU) and inertial space through precisely controlled physical motion, thereby modulating and compensating for the errors of the inertial sensor. Typical implementation methods include continuous rotation and multi-position rotation / stop modes.

[0085] Non-rotational self-calibration methods primarily achieve autonomous system calibration through three technical approaches: parameter identification based on analytical modeling, online calibration utilizing physical constraints, and data fusion based on hardware redundancy. Analytical modeling requires constructing an accurate mathematical model containing various system error terms, identifying parameters in the model by applying specific external stimuli and observing the system response. Physical constraint methods fully utilize natural physical benchmarks such as the Earth's gravitational field and geomagnetic field, using kinematic constraints to invert sensor error parameters in real time during normal system operation. Hardware redundancy schemes construct a redundant structure by installing multiple similar sensors, utilizing cross-validation and optimal estimation to achieve system self-diagnosis and parameter self-calibration. These methods completely avoid mechanical rotating mechanisms, significantly reducing system complexity, size, and power consumption.

[0086] With the help of self-calibration control, the equipment can achieve long-term low-maintenance operation, eliminating the cumbersome process of recalibrating traditional inertial measurement equipment (such as fiber optic gyroscopes) every 3 years to ensure the accuracy of measurement data.

[0087] Intrinsic safety protection features: Built-in overcurrent, overvoltage and anti-static protection logic, integrated isolation optocoupler, capable of isolating voltages up to 1500V, effectively preventing high voltage from entering the low voltage control terminal, and real-time monitoring of system parameters to trigger the protection mechanism.

[0088] In another embodiment, the inertial navigation calculation function of the main processor in the processing unit can be ported to the ASIC, such as... Figure 5 As shown, the ASIC also includes inertial navigation (INS) calculation functionality: this function calculates the gyroscope's attitude and the accelerometer's position and velocity, incorporating a built-in Kalman filter algorithm to calculate the gyroscope's carrier attitude, position, and trajectory in real time; the Kalman filter utilizes the high-frequency calculation results from the INS to predict the gyroscope's next carrier state (position, velocity, attitude, and sensor error). Specifically, the resonant gyroscope signal, external input signals (including but not limited to BDS, GPS, USBL, and total station), and accelerometer input signals are calculated and then output from the interface circuit as attitude angle data and trajectory output.

[0089] The technical solution of the present invention can achieve the following technical effects:

[0090] Since this invention is used in underground mining operations, it requires miniaturization and high integration. The resonant gyroscope has this advantage, reducing the size to more than 30% of that of traditional fiber optic inertial navigation systems. Furthermore, the device uses an ASIC chip, which reduces the volume by more than 40% compared to previous processing circuits, and also reduces power consumption by 30%.

[0091] This invention employs a vacuum shield that is heat-resistant, adaptable to underground mining conditions, and its ASIC circuit meets energy safety verification requirements. The vacuum also provides flame retardancy. Specifically, the total capacitance C_total (including flying capacitors, output capacitors, and parasitic capacitances at critical nodes) is estimated to be approximately 58pF. With the maximum operating voltage V_max set at 300V, the maximum energy storage E_max = 0.5 × 58pF × (300V) 2 = 2.61μJ << 200μJ (minimum ignition energy of methane), meeting the national standard requirements for intrinsic safety certification and testing; fundamentally resolving the conflict between high-voltage excitation and intrinsic safety by ASIC-izing the high-voltage generation function and embedding it within a vacuum chamber, physically limiting the scale and energy storage of the high-voltage circuit, ensuring its inherent energy is below the ignition limit, thus achieving true intrinsic safety; compared to directly placing the high-voltage unit within an explosion-proof enclosure, the technical solution of this invention not only achieves physical "isolation," ensuring intrinsic safety testing, but also eliminates the risk of combustion and explosion, and the equipment is lightweight and easy to install.

[0092] The high-voltage signal is generated and used locally within the cavity, avoiding interference during long-distance transmission and ensuring the purity and accuracy of the drive signal.

[0093] The ASIC chip of this invention integrates multiple functions. With the help of self-calibration control and intrinsically safe protection logic, the device can achieve long-term low-maintenance operation, eliminating the cumbersome process of recalibrating traditional inertial measurement equipment every 3 years to ensure the accuracy of measurement data, thereby effectively reducing downhole operation costs.

[0094] Both the sensing head and processing unit of this invention meet intrinsic safety requirements. An intrinsically safe barrier circuit is provided between the sensing head and the processing unit to ensure that the voltage, current, and total power entering the hazardous area under any fault condition are limited to safe ranges.

[0095]

Example 2

[0096] In this embodiment, as Figure 3 As shown, the intrinsically safe inertial navigation measurement device for mining includes a physically separate intrinsically safe sensor head and a processing unit, which are connected by an intrinsically safe cable and a connector.

[0097] The intrinsically safe sensor head includes: a vacuum shield, such as Figure 2 As shown, its internal components include: a resonant gyroscope core, which is an intrinsically safe μHRG (diamond resonator); an intrinsically safe high-voltage excitation application-specific integrated circuit (ASIC) specifically for exciting the diamond resonant gyroscope; and a micro preamplifier for detecting the vibration signal of the resonator.

[0098] A diamond resonant gyroscope is a waveguide optical gyroscope. Its core sensing element is not a traditional mechanical rotor or MEMS vibration structure, but an optical resonant cavity made of high-quality synthetic diamond. When the gyroscope rotates, the Coriolis force causes a change in the resonant mode. By detecting this change, the rotational angular velocity can be accurately measured, which is the foundation for achieving ultra-high precision. Its characteristics include: 1. Ultra-high theoretical accuracy: aiming to achieve or even exceed a bias instability of 0.001° / h; 2. No moving parts, strong resistance to shock and vibration, and long lifespan; 3. Small size and low power consumption: its core resonant cavity can be made very small (chip-level), suitable for integration; 4. Fast start-up: no warm-up time required like traditional high-precision gyroscopes; 5. Multifunctional integration: the diamond platform can simultaneously integrate a gyroscope, accelerometer, and magnetometer.

[0099] An excitation electrode is fabricated on a specific area of ​​the diamond resonator, and an alternating driving voltage is applied. This alternating voltage generates an alternating electric field. In order to generate a sufficiently large electrostatic force to drive the hard diamond, the driving voltage (V) must be high enough.

[0100] Preferably, in this embodiment, the intrinsically safe sensor head is a vacuum shield (vacuum degree <10). -3 The Pa) is equipped with a resonant gyroscope core (resonant gyroscope core: made of artificial diamond, fabricated by MEMS process, diameter = 20mm) and an intrinsically safe high-voltage excitation ASIC (0.35μm BCD process, 6-stage charge pump, 6×4pF flying capacitor).

[0101] The intrinsically safe sensor head is designed to meet intrinsic safety standards. In this invention, "intrinsically safe" means that the electrical equipment meets the current GB intrinsically safe explosion-proof standard (GB 3836.4-2010) and can pass intrinsically safe testing.

[0102] The processing unit includes: an intrinsically safe power supply module for powering the entire system; a main processor (including signal processing and digital waveform generator); and a communication interface circuit; wherein:

[0103] Intrinsically safe power module: output voltage = 5V, maximum current = 60mA, conforming to intrinsically safe "ib" level.

[0104] The communication interface circuit uses a CAN bus to communicate with the mine truck control system, enabling continuous navigation without GPS.

[0105] Digital waveform generators (such as PWM peripherals of FPGAs or processors) generate low-voltage digital control signals, such as PWM waves or digital serial commands, to drive the resonator. Their physical levels are safe CMOS or LVDS levels (such as 3.3V).

[0106] Preferably, the main processor uses an ARM Cortex-M4 to generate a 5kHz PWM signal, which is then output via optocoupler isolation and an intrinsically safe barrier (1kΩ current-limiting resistor + 5.1V Zener diode).

[0107] In addition to low-voltage digital control signals, the signals output by the processing unit also include low-voltage DC power supplies for the ASIC. These low-voltage DC power supplies must pass through an intrinsically safe barrier circuit before output. This barrier circuit consists of precision current-limiting resistors and voltage-regulating / clamping diodes, ensuring that the voltage, current, and total power entering the hazardous area under any fault condition are limited to safe ranges. The low-voltage DC power supply signal output from the intrinsically safe power supply and the low-voltage digital control signal output from the digital waveform generator are transmitted through a ceramic-metal vacuum feedthrough connector into the vacuum shield, and then delivered to the intrinsically safe high-voltage excitation ASIC.

[0108] The ASIC integrated control module integrates signal processing, calibration-free operation, and intrinsically safe protection functions. Specifically:

[0109] Signal processing function: Supports force balance mode signal processing, square wave drive (15kHz).

[0110] Self-calibration control function: It uses methods such as "non-selective rotation" to compensate for gyroscope errors and achieve long-term calibration-free operation of the system;

[0111] Intrinsic safety protection features: Built-in overcurrent, overvoltage and anti-static protection logic, integrated isolation optocoupler, capable of isolating voltages up to 1500V, effectively preventing high voltage from entering the low voltage control terminal, and real-time monitoring of system parameters to trigger the protection mechanism.

[0112] It can also integrate inertial navigation calculation functions: it has built-in algorithms such as Kalman filtering to calculate attitude, position and motion trajectory in real time.

[0113] For other structures, functions, and technical effects, please refer to Specific Embodiment 1.

[0114] In other embodiments, other resonant gyroscopes, such as metal resonators, may also be used.

[0115] The core of a metal resonant gyroscope is a symmetrical resonant structure (typically ring-shaped, cylindrical, or tuning fork-shaped) made of a special metal alloy (such as Invar, a nickel-iron alloy). This structure is excited to resonate, and the Coriolis effect is used to sense the rotational angular velocity. Because it has no moving friction parts, the entire system is a solid-state structure, exhibiting high reliability and long lifespan. Compared to optical gyroscopes that require preheating, metal resonant gyroscopes can reach a stable operating state within milliseconds to seconds after being powered on.

[0116] When the core of the resonant gyroscope is a metal resonator, the intrinsically safe high-voltage excitation dedicated integrated circuit is replaced by a corresponding low-voltage driving circuit.

[0117] If other types of gyroscopes, such as fiber optic gyroscopes or laser gyroscopes, are used, the structure of this invention can also be adopted, and the intrinsically safe high-voltage excitation dedicated integrated circuit is replaced by a corresponding low-voltage drive circuit.

[0118] This invention also provides an intrinsically safe inertial navigation system for mining applications, such as... Figure 6 As shown, the inertial navigation system includes three of the aforementioned resonant gyroscope-based inertial navigation devices. The inertial navigation system also includes a three-axis accelerometer, which can be installed orthogonally or non-orthogonally. In the case of non-orthogonal installation, the initial installation angle and the corresponding transformation coordinate system need to be calibrated. The three-axis gyroscope and the three-axis accelerometer correspond to the three axes (X, Y, Z axes). The navigation computer is communicatively connected to the processing unit in the inertial navigation device and outputs the navigation calculations.

[0119] An inertial navigation system (INS) is a navigation parameter calculation system based on gyroscopes and accelerometers. Its core lies in establishing a navigation coordinate system using the output of the gyroscope and combining this with the output of the accelerometer to further calculate the vehicle's velocity and position within that coordinate system. In an INS, the gyroscope plays a central role, not only in constructing the navigation coordinate system but also in ensuring the accelerometer's measurement axis remains stable within it, thus providing accurate measurements of heading and attitude angles. The accelerometer, on the other hand, measures the acceleration of the moving body, and through integration, obtains velocity and displacement information.

[0120] Navigation solution is a rigorous and complex mathematical process:

[0121] 1. Using gyroscope data, update the carrier's attitude (pitch angle, roll angle, yaw angle) by solving the attitude differential equations.

[0122] 2. Using an attitude matrix, the accelerometer data is converted to the navigation coordinate system, and gravity and harmful acceleration are compensated to obtain the true motion acceleration;

[0123] 3. Integrate the actual acceleration twice to update the velocity and position;

[0124] 4. Utilizing algorithms such as Kalman filtering, information from sensors like magnetometers is deeply fused with INS calculation results to estimate and compensate for system errors in real time, outputting stable, accurate, and reliable navigation information. The role of Kalman filtering is essentially that of an optimal estimation algorithm. It has two models:

[0125] 1. Prediction (state equation): Using the high-frequency solution results of INS, predict the next state of the carrier (position, velocity, attitude, and sensor error).

[0126] 2. Update (Measurement Equation): When external sensors such as BDS, GPS, USBL, and total station provide low-frequency but absolutely accurate observation data (e.g., position, velocity), the filter compares the INS prediction with the GPS observation and performs a weighted average based on their uncertainties (covariance) to obtain an optimal, corrected state estimate. Kalman filtering not only corrects for position, velocity, and attitude, but also estimates the errors of the gyroscope and accelerometer (e.g., bias) in real time, and uses these estimates to correct the original sensor data, forming a closed-loop feedback that greatly suppresses the drift of the entire system.

[0127] In addition to the aforementioned technical advantages, the intrinsically safe inertial navigation system of this invention has strong compatibility and scalability, supports various gyroscope types such as fused silica resonant gyroscope (HRG), metal resonant gyroscope, and μHRG, and is suitable for different mining application scenarios; it also has excellent engineering prospects: based on mature integrated circuit and vacuum packaging technology, it is suitable for mass production and deployment in harsh mining environments.

[0128] The system is applied to scenarios such as underground equipment positioning, tunnel navigation, or mine car attitude monitoring in mines, and communicates and integrates with existing mine equipment through a CAN bus or RS485 interface.

[0129] It should be noted that, in this document, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a process, method, article, or apparatus. Unless otherwise specified, an element defined by the phrase "comprising one..." does not exclude the presence of other identical elements in the process, method, article, or apparatus that includes that element.

[0130] The sequence numbers of the above embodiments of the present invention are for descriptive purposes only and do not represent the superiority or inferiority of the embodiments.

[0131] Through the above description of the embodiments, those skilled in the art can clearly understand that the above implementation methods can be implemented by means of software plus necessary general-purpose hardware platforms. Of course, they can also be implemented by hardware, but in many cases the former is a better implementation method. Based on this understanding, the technical solution of the present invention, in essence, or the part that contributes to the prior art, can be embodied in the form of a software product. This computer software product is stored in a storage medium (such as ROM / RAM, magnetic disk, optical disk), and includes several instructions to cause a terminal (which may be a mobile phone, computer, server, air conditioner, or network device, etc.) to execute the methods described in the various embodiments of the present invention.

[0132] The embodiments of the present invention have been described above with reference to the accompanying drawings. However, the present invention is not limited to the specific embodiments described above. The specific embodiments described above are merely illustrative and not restrictive. Those skilled in the art can make many other forms under the guidance of the present invention without departing from the spirit and scope of the claims. All of these forms are within the protection scope of the present invention.

Claims

1. A mine-used intrinsically safe inertial navigation measuring device based on a resonator gyroscope technology, characterized in that, The measuring device comprises an intrinsic safety sensing unit and a signal processing unit, wherein: The intrinsic safety sensing unit comprises a resonant gyroscope and a high-voltage excitation application-specific integrated circuit; The high-voltage excitation application-specific integrated circuit converts low-voltage direct current and low-voltage digital control signals output by the signal processing unit into high-voltage alternating current driving signals for driving the resonant gyroscope; Output signals of the resonant gyroscope are output to the processing unit, and the signal processing unit outputs to an upper computer after inertial navigation calculation and processing; The intrinsic safety sensing unit is placed in a vacuum shield cover; The intrinsic safety sensing unit and the signal processing unit are connected through an intrinsic safety cable; Capacitors used in the high-voltage excitation application-specific integrated circuit are all pF level, so that the maximum release energy of the circuit in the vacuum shield cover under any fault state is lower than 2.61 microjoules; The high-voltage excitation application-specific integrated circuit comprises: A control logic circuit for analyzing the low-voltage digital control signal; A charge pump direct current boost circuit for converting the low-voltage direct current into high-voltage direct current; An inverter circuit for inverting the high-voltage direct current into high-voltage alternating current; A feedback control circuit for precisely controlling the amplitude of the high-voltage alternating current by adjusting the output voltage of the charge pump, generating a high-voltage alternating square wave signal, and modulating the high-voltage alternating square wave by the low-voltage digital control signal, and outputting a high-voltage alternating square wave driving signal for driving the resonant gyroscope.

2. The inertial navigation measurement device of claim 1, wherein, The resonant gyroscope is a hemispherical resonant gyroscope, a μHRG or a metal resonant gyroscope.

3. The inertial navigation measurement device of claim 2, wherein, The resonant gyroscope is a hemispherical resonant gyroscope, which comprises a resonator and a detection base, the detection base is provided with excitation electrodes and detection electrodes, the resonator is a fused quartz resonator, and the excitation electrodes and the detection electrodes are annularly and spacedly arranged.

4. The inertial navigation measurement device of claim 1, wherein, A vacuum feedthrough connector is arranged on the vacuum shield cover and connected with the intrinsic safety cable.

5. The inertial navigation measurement device of claim 1, wherein, The bottom of the vacuum shield cover is filled with insulating heat-conducting glue.

6. The inertial navigation measurement device of claim 1, wherein, The vacuum shield cover is made of high-temperature-resistant material by 3D printing.

7. The inertial navigation measurement device of claim 1, wherein, The output signals of the resonant gyroscope are output to the signal processing unit through the intrinsic safety cable after being conditioned by a micro preamplifier.

8. The inertial navigation measurement device of claim 5, wherein, The high-voltage excitation application-specific integrated circuit comprises the following functional modules: A signal conditioning module for supporting full-angle mode or force balance mode and conditioning the output signals of the detection electrodes of the resonant gyroscope; A self-calibration control module for realizing calibration-free operation of the resonant gyroscope system in a non-selected rotation mode; An intrinsic safety protection module for monitoring the working parameters of the measuring device in real time and triggering the protection mechanism when an abnormality occurs, comprising overcurrent monitoring, overvoltage protection and anti-static control.

9. The inertial navigation measurement device of claim 1, wherein, The signal processing unit comprises: An intrinsic safety power supply module for outputting low-voltage direct current power supply signals; A main processor comprising a signal calculation module and a digital waveform generator, the signal calculation module receives resonant gyroscope signals and external input signals transmitted from the intrinsic safety sensing unit, and outputs attitude angle data and carrier motion trajectory from an interface circuit after inertial navigation calculation, and the digital waveform generator outputs low-voltage digital control signals; An intrinsic safety barrier circuit composed of a precision current-limiting resistor and a voltage stabilizing / clamping diode.

10. The inertial navigation measurement device of claim 9, wherein, The signal solution module can be integrated into the high voltage driver ASIC.

11. A mine-used intrinsically safe inertial navigation measurement system based on resonator gyroscope technology, characterized in that, The measurement system comprises a plurality of inertial navigation measurement devices as claimed in any one of claims 1 to 10 and a plurality of accelerometers.

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