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Discover how high-temperature accelerometers from Micro-Magic ensure accurate vibration and acceleration data in extreme conditions (-55°C to +180°C). Ideal for oil & gas, aerospace, automotive, and industrial applications. In industries such as oil and gas, aerospace, and automotive testing, equipment often needs to operate in extreme temperature conditions. How can we ensure that accurate vibration and acceleration data can still be obtained in these harsh environments? The high-temperature accelerometer is precisely the key technology designed to address this challenge. This article will take you through the working principles, core application scenarios, and innovative solutions of Micro-Magic in this field by introducing these "industrial temperature warriors". What is a high-temperature accelerometer? A high-temperature accelerometer is a sensor specifically designed for extreme environments, capable of maintaining stable operation within a temperature range of -55°C to +180°C (such as the AC-4 model by Micro-Magic). Compared to traditional accelerometers, it adopts special materials and structural designs to ensure that it can still provide accurate measurement data under high temperatures, high vibrations, and strong impacts. Take Micro-Magic's quartz accelerometer as an example. It uses a non-crystalline quartz mass block structure, responding to changes in acceleration through bending motion. This design brings three major advantages: Bias stability: <10mg (AC-4 model) Temperature sensitivity: <100ppm Axis alignment stability: Ensuring long-term measurement consistency The four core application scenarios of high-temperature accelerometers 1. Oil and gas industry: "Underground navigator" for drilling operations In the MWD (Measurement While Drilling) system, high-temperature accelerometers play an irreplaceable role. Taking the AC-6 (a dedicated model for MWD) as an example, it can withstand underground high temperatures (up to 150°C) and 1000g of impact, providing three key supports for drilling operations: Real-time positioning: Accurately measure the position and inclination of the drill bit, improving drilling accuracy Safety warning: Detect abnormal vibrations to prevent downhole accidents Efficiency optimization: Reduce non-productive time through continuous monitoring, according to industry reports, it can reduce operation costs by 15-20% 2. Aerospace: The "Silent Guardian" of Flight Safety The aircraft engines and fuselage structures endure extreme conditions during flight. The high-temperature accelerometer from Micro-Magic (such as the AC-3 shock-resistant model) provides triple guarantees for the aerospace industry: Structural health monitoring: Real-time measurement of vibration in key components to prevent fatigue damage Engine diagnosis: Detection of abnormal vibration patterns to identify potential faults in advance Flight testing: Provision of precise dynamic performance data during the development of new aircraft models 3. Vehicle Testing: "Performance Judges" under Extreme Conditions From crash tests to high-performance validations, the high-temperature accelerometer provides objective quantitative data for the automotive industry: Crash Safety: Measuring instantaneous impact forces (up to ±30g range), evaluating the effectiveness of safety systems Durability Test: Long-term monitoring of component vibration characteristics in high-temperature environments Performance Validation: Ensuring the reliability of sports cars and racing cars under extreme driving conditions 4. Industrial Applications: Key Sensors for Intelligent Manufacturing In fields such as power plants, heavy industry, and special robots, high-temperature accelerometers also prove their worth: Turbine monitoring: A key data source for preventive maintenance Heavy machinery: Vibration monitoring can extend equipment lifespan by over 30% Industrial robots: Especially in high-temperature working units such as welding and casting Micro-Magic's Innovative Solutions: Designed for Extreme Environments As a leading supplier of inertial systems in the industry, Micro-Magic's high-temperature accelerometer series boasts several unique advantages: 1. Flexible Configuration: Analog output for easy system integration Multiple installation options for square/round flanges On-site adjustable range (e.g., ±10g to ±30g) 2. Intelligent Temperature Compensation: Built-in temperature sensor for automatic thermal compensation, ensuring measurement accuracy across the entire temperature range 3. Thermal Protection Design: Some models are equipped with an external amplifier, effectively isolating the impact of high temperatures on sensitive components 4. Recommended Models: AC-4: The top choice in the oil and gas industry, with a working temperature range of -55 to 180°C, and a bias repeatability of <50μg AC-6: Specifically designed for MWD, with shock resistance of 1000g, suitable for deep well measurements AC-3: Anti-vibration type, suitable for aerospace high-frequency vibration environments Cutting-edge Technology and Future Outlook As industrial equipment operating conditions become increasingly demanding, high-temperature accelerometer technology is also continuously evolving. The new generation of products being developed by Micro-Magic will feature: A wider working temperature range (-65 to 200°C) Higher vibration tolerance (2000g shock) Digital output and wireless transmission capabilities Conclusion High-temperature accelerometers are indispensable "sensory extensions" in modern industry. They continuously provide reliable measurement data in extreme environments that are beyond human vision and reach. Choosing the right high-temperature accelerometer not only enhances operational efficiency but also serves as a crucial guarantee for safe production. If you are looking for a solution for high-temperature accelerometers suitable for specific applications, please contact our technical team for customized advice. Share your experiences or questions in the comment section, and we will provide you with detailed answers! AC-4 Whatever you needs, Micro-Magic is at your side. AC-3 Whatever you needs, Micro-Magic is at your side. AC-6 Whatever you needs, Micro-Magic is at your side.

Explore the impact of temperature drift on Fiber Optic Gyroscopes (FOGs), effective compensation methods, and experimental results. Learn how third-order polynomial models improve accuracy by 75%. Fiber Optic Gyroscopes (FOGs), as a new type of high-precision angular rate measurement instrument, have been widely used in military, commercial, and civilian applications due to their compact size, high reliability, and long lifespan, demonstrating broad development prospects. However, when operating temperatures fluctuate, their output signals exhibit drift, significantly affecting measurement accuracy and limiting their application scope. Therefore, studying the drift patterns of FOGs and implementing error compensation has become a critical challenge to enhance their adaptability in varying temperature environments. Mechanisms of Temperature Effects on Fiber Optic Gyroscopes FOGs are optical gyroscopes based on the Sagnac effect, composed of a light source, photodetector, beam splitter, and fiber coil. Temperature impacts gyroscope accuracy by interfering with the performance of internal components: Fiber Coil: As the core component, the fiber coil generates the Sagnac effect when rotating relative to inertial space. Temperature disturbances disrupt the structural reciprocity of the FOG, leading to phase difference errors. Photodetector: Environmental temperature variations introduce significant noise in the detector and produce a temperature-dependent dark current. The load resistance of the detector is also affected by temperature. Light Source: The temperature performance of the light source is closely related to the precision of the Sagnac phase shift. Variations in output power, mean wavelength, and spectral width under different temperatures further influence the gyroscope's output signal. Existing Methods for Temperature Drift Compensation Currently, there are three primary methods to mitigate temperature drift: Hardware Temperature Control Devices: Adding localized temperature control systems to FOGs can compensate for temperature errors in real time. However, this increases volume and weight, conflicting with the trend toward miniaturization. Mechanical Structure Modifications: Techniques like the quadrupole winding method ensure symmetric temperature effects on the fiber coil, reducing non-reciprocal interference. However, residual drift still affects angular rate detection. Software Modeling Compensation: Establishing temperature models for compensation saves space and reduces costs, making it the mainstream method in engineering practice. Temperature Experiments and Modeling Analysis Experimental Design Tests were conducted in three temperature ranges: 0°C to 20°C-40°C to -20°C40°C to 60°C The initial temperature of the thermal chamber was set, maintained for 4 hours, and then adjusted at a rate of 5°C/h. Gyroscope output data was recorded. The test system is shown in Figure 1, with a sampling interval of 1 second and data smoothed over 100 seconds. Key Findings Analysis of the output curves revealed: The gyroscope output exhibited significant oscillations with temperature changes. The output curve followed the same upward or downward trends as the temperature rate curve. Temperature drift was closely related to internal temperature and its rate of change.  Compensation Model A third-order polynomial compensation model was developed, incorporating the following factors: Temperature Factor Model: Lout=L0+∑i=13ai(T−T0)i+∑j=13bjTjLout​=L0​+i=1∑3​ai​(T−T0​)i+j=1∑3​bj​Tj​ After compensation, the bias stability reached 0.0200°/h. Temperature Rate Model:Introducing the temperature rate term improved bias stability to 0.0163°/h. Comprehensive Model:By considering both temperature and its rate of change, bias stability significantly improved to 0.0055°/h, achieving a 77% reduction in error. Segmented Compensation Results Different parameters were applied for compensation across temperature ranges, with results as follows: Gyro Axis Temperature Range Pre-Compensation Error (°/h) Post-Compensation Error (°/h) Error Reduction Percentage X-Axis 0°C to 20°C 0.02504 0.00518 79%   -40°C to -20°C 0.02404 0.00550 77%   40°C to 60°C 0.02329 0.00603 74% Y-Axis 0°C to 20°C 0.02307 0.00591 74%   -40°C to -20°C 0.02535 0.00602 76%   40°C to 60°C 0.02947 0.00562 80% Z-Axis 0°C to 20°C 0.01877 0.00495 74%   -40°C to -20°C 0.02025 0.00649 73%   40°C to 60°C 0.01413 0.00600 58% After compensation, the oscillation amplitude of the output curves was significantly suppressed, becoming more stable. The average error reduction across the three temperature ranges was approximately 75%. Conclusion and Outlook The proposed third-order bias temperature compensation model, which accounts for current temperature, initial temperature deviation, and temperature rate, has been experimentally proven to effectively improve gyroscope output signals and significantly enhance accuracy. This method can be applied to Micro-Magic's FOG models such as U-F3X80, U-F3X90, U-F3X100, U-F100A, and U-F300. However, current research still has limitations, such as discontinuous temperature history and insufficient sample coverage. Future work should focus on developing compensation methods for temperature drift across the full temperature range. For engineering applications, software modeling compensation demonstrates great potential as a cost-effective solution to balance precision and practicality.   U-F3X90 Whatever you needs, Micro-Magic is at your side. U-F3X100 Whatever you needs, Micro-Magic is at your side. U-F100A Whatever you needs, Micro-Magic is at your side. --

Explore the working principles, military/civilian applications, and market prospects of tactical-grade fiber optic gyroscopes (FOGs). Learn about top products like GF-3G70 and GF-3G90, and discover their role in aerospace, UAVs, and more. 1. Introduction In the field of modern inertial navigation, Fiber Optic Gyroscopes (FOGs) have become one of the mainstream devices due to their unique advantages. Today, we will delve into the working principles, current market status, and typical product applications of this technology, with a special focus on the performance characteristics of tactical-grade fiber optic gyroscopes. 2. Working Principles of Fiber Optic Gyroscopes A fiber optic gyroscope is an all-solid-state fiber optic sensor based on the Sagnac effect. Its core component is a fiber optic coil, where light emitted by a laser diode propagates in two directions along the coil. When the system rotates, the propagation paths of the two light beams produce a difference. By measuring this optical path difference, the angular displacement of the sensitive component can be precisely determined. Simply put, imagine emitting two beams of light in opposite directions on a circular track. When the track is stationary, the two beams will return to the starting point simultaneously. However, if the track rotates, the light moving against the rotation direction will "travel a longer distance" than the other beam. The fiber optic gyroscope calculates the rotation angle by measuring this minute difference. 3. Technical Classification and Market Status Based on their working methods, fiber optic gyroscopes can be divided into: Interferometric Fiber Optic Gyroscope (I-FOG) Resonant Fiber Optic Gyroscope (R-FOG) Brillouin Scattering Fiber Optic Gyroscope (B-FOG) In terms of accuracy levels, they include: Low-end tactical gradeHigh-end tactical gradeNavigation gradePrecision grade Currently, the fiber optic gyroscope market exhibits dual-use characteristics for military and civilian applications: Military applications: Attitude control for fighter jets/missiles, tank navigation, submarine heading measurement, etc. Civilian applications: Car/aircraft navigation, bridge measurement, oil drilling, etc. It is worth noting that medium-to-high precision fiber optic gyroscopes are primarily used in high-end military equipment such as aerospace, while low-cost, low-precision products are widely applied in civilian fields like oil exploration, agricultural aircraft attitude control, and robotics. 4. Technical Challenges and Development Trends The key to achieving high-precision fiber optic gyroscopes lies in: 1. Studying the impact of optical devices and physical environments on performance. 2. Suppressing relative intensity noise. With the advancement of optoelectronic integration technology and specialty optical fibers, fiber optic gyroscopes are rapidly developing toward miniaturization and cost reduction. Integrated, high-precision, and miniaturized fiber optic gyroscopes will become the mainstream in the future. 5. Recommended Tactical-Grade Fiber Optic Gyroscope Products Taking Micro-Magic Company's products as an example, their tactical-grade fiber optic gyroscopes are characterized by medium precision, low cost, and long lifespan, offering significant price advantages in the market. Below are two popular products: GF-3G70 Performance Characteristics:Bias stability: 0.02~0.05°/h Typical Applications:Electro-optical pods/flight control platformsInertial Navigation Systems (INS)/Inertial Measurement Units (IMU)Platform stabilization devicesPositioning systemsNorth seekers GF-3G90 Performance Characteristics:Higher bias stability: 0.006~0.015°/hLong lifespan, high reliability Typical Applications:UAV flight controlMapping and orbital inertial measurementElectro-optical podsPlatform stabilizers 6. Conclusion Fiber optic gyroscope technology holds significant strategic importance for a country's industrial, defense, and technological development. With technological advancements and the expansion of application scenarios, fiber optic gyroscopes will play a critical role in more fields. Tactical-grade products, with their excellent cost-performance ratio, are gaining widespread application in both military and civilian markets. G-F3G70 Tri-Axis Fiber Optic Gyroscope G-F70ZK Medium and High Precision  Fiber Optic Gyroscope G-F3G90 Tri-Axis Fiber Optic Gyroscope --

Discover the innovative design of a miniaturized Fiber Optic Gyroscope (FOG) IMU, offering high precision, low power consumption, and redundancy for aerospace, navigation, and industrial applications. Learn about its technical advantages and performance 1. Overview With the increasing demand for inertial navigation systems in aerospace, high-end navigation, and industrial applications, miniaturization, low power consumption, and high reliability have become key indicators. This article presents an innovative design solution for a miniaturized Fiber Optic Gyroscope (FOG) IMU based on 40 years of FOG technology accumulation and verifies its excellent performance through engineering validation. 2. Technical Background Fiber Optic Gyroscope (FOG) measures angular velocity using the Sagnac effect. Since its introduction in 1976, FOG has gradually replaced traditional mechanical and laser gyroscopes due to its solid-state structure, high reliability, and fast startup advantages. 3. System Architecture Design This IMU system consists of two core components: the IMU module and the IMU circuit. The module includes four FOGs and four quartz flexure accelerometers, using a 4S structure. Any combination of three axes can achieve three-dimensional measurement of angular velocity and acceleration, with 1 degree of freedom redundancy to improve fault tolerance.The circuit system includes the main/backup interface circuit and the power management module. The main/backup interface provides cold-hot backup and is responsible for acquiring sensor signals and communicating with the navigation system in addition to providing secondary power. The power management module independently controls the power on/off of each channel sensor, enhancing system integration and power regulation capabilities. 4. Core Device and Circuit Optimization The miniaturized power management design utilizing LSMEU01 interface circuit based on SIP packaging and magnetic latching relays reduces the volume of the entire IMU circuit by approximately 50% and controls the weight to 0.778kg. The accelerometer adopts a temperature compensation strategy based on combined parameters, optimizing the power consumption of a single channel to 0.9W, effectively reducing the overall thermal load.Performance IndicatorsTotal weight: 850gStructure: Redundant configuration with 4 FOGs + 4 accelerometersApplication Environments: Aerospace, drilling surveying, dynamic communication platforms, and other scenarios with strict requirements on size, power, and performance. 5. Future Prospects This design has completed integrated testing in multiple typical systems and demonstrates stable and reliable performance. As one of the smallest FOG IMUs on the market, U-F3X90 is suitable for applications such as Attitude and Heading Reference Systems (AHRS), flight control systems, inertial/satellite fusion navigation platforms, and high-dynamic industrial equipment. It provides a high-precision, low-power solution for various high-end applications.     U-F3X90 Fiber Optic Gyroscope IMU   --

Discover how wireless inclination sensors revolutionize the measurement of aircraft wing surface deflection. Through the optimization of the dual-axis error model and the wireless real-time system, achieve 0.05° accuracy and efficient installation, enhancing aircraft manufacturing efficiency and safety. In the field of aircraft manufacturing, the precise control of wings and control surfaces directly affects flight performance and safety. With the popularization of modular assembly technology, how to quickly and efficiently detect the deflection angle of moving wing surfaces has become a key challenge for improving production line efficiency. Traditional detection methods rely on complex mechanical fixtures and wired sensors, which are cumbersome to install and time-consuming, and thus difficult to meet the modern high-precision and real-time production requirements.Today, we will deeply explore an innovative solution based on wireless inclination sensors, which not only simplifies the installation process but also pushes the measurement accuracy to a new level through improved error models and calibration algorithms. 1. Technical Challenges: Why Wireless Inclination Sensors Are Needed? The detection of deflection angles of aircraft movable surfaces (such as flaps and ailerons) faces multiple challenges:Installation complexity: Traditional methods require customizing multiple mechanical fixtures, which are time-consuming and labor-intensive for workers.Lack of real-time performance: Wired sensors' wiring limits mobility and makes it difficult to adapt to dynamic testing scenarios.High precision requirements: The deflection angle of the wing surfaces needs to be controlled within 0.05°, and high-frequency sampling (>10Hz) is required.Although existing methods (such as laser tracking and inertial measurement) have their own advantages, they often struggle to balance portability, precision, and cost. However, the emergence of wireless inclination sensors provides a better solution to this problem. 2. Solution: Dual-axis Error Model and Breakthrough in Wireless Systems (1) Optimization of Dual-axis Spatial Angle Error Model For the scenario where the wing surface deflects around the horizontal axis, the research team proposed an improved dual-axis measurement error model:Introducing new error variables to solve the calibration problem when the sensor installation plane is not parallel.Using an automatic calibration algorithm in software, the sensor output error is controlled within the allowable range (<0.05°).This optimization significantly improves the measurement stability under complex conditions, especially for dynamic tests of large-sized wing surfaces. (2) Wireless Communication and Real-time Visualization System The system adopts wireless transmission protocols (such as Modbus) to completely break free from the constraints of wired cables:Installation is convenient: No wiring required. Sensors can be installed and used immediately, reducing the complexity of on-site operations.Real-time feedback: Data, curves, and three-dimensional models are displayed synchronously, providing intuitive monitoring of the wing surface motion state.High-frequency acquisition: The data update rate exceeds 10Hz, ensuring the accurate capture of dynamic processes. (3) Error Coupling Analysis and Future Directions The current model has considered installation errors, but in practical applications, various errors (such as temperature drift, mechanical vibration) may have coupling effects. The next research plan is to further enhance the comprehensive accuracy of the calibration model through systematic error identification. 3. Practical Application: Dual Enhancement of Efficiency and Precision In a large-scale aircraft wing surface test, this system has been verified on-site:Efficiency Enhancement: The wireless solution has shortened the calibration time by 50% and reduced the worker operation steps by 70%.Precision Assurance: The deflection angle measurement error is less than 0.05°, meeting the requirements for high-precision assembly.Extensive Adaptability: The system supports multi-sensor networking and can be adapted to different aircraft models and wing surface types. 4. Technical selection recommendation: High-precision wireless inclinometer Micro-Magic's two very popular wireless tilt sensors, T7000-I  accuracy can reach 0.001°, resolution 0.0005°, T7000-K accuracy moderate 0.1°, resolution 0.01°, you can choose according to your own needs, If you are interested in our wireless tilt sensors, please feel free to contact us.   5. Conclusion The breakthrough in wireless tilt sensor technology not only provides a more efficient tool for wing surface detection of aircraft but also opens up new ideas for industrial automated measurement. In the future, with the continuous optimization of error models and the integration of 5G technology, this solution is expected to play a key role in more dynamic scenarios.If you have any questions about technical details or sensor selection, please feel free to leave a message for communication! We look forward to exploring the infinite possibilities of intelligent measurement together with you. T7000-I (Low power) Full Temperature Compensation High-Precision Wireless Transmission Tilt Sensor   T70000-K Wireless transmission inclination sensor  

Explore high-precision calibration for FOG IMU (Fiber Optic Gyro Inertial Measurement Unit) across full temperature ranges. Learn key error modeling techniques, 3D bidirectional rate/one-position calibration, and Piecewise Linear Interpolation (PLI) compensation for enhanced navigation accuracy in drones, autonomous vehicles, and robotics. How can FOG IMU (Inertial Measurement Unit based on Fiber Optic Gyroscope) maintain high precision in complex temperature environments? This article comprehensively analyzes its error modeling and compensation methods. 1. Introduction to FOG IMU: The "Brain" of Flight Navigation System In modern aircraft, especially in small rotor unmanned aerial vehicle systems, FOG IMU is the core component of the navigation information and attitude measurement system. The fiber optic gyroscope (FOG) based on the Sagnac effect has advantages such as high precision, strong shock resistance, and fast response, but it has poor adaptability to temperature changes. This can easily lead to measurement errors during the flight process where the dynamic environment changes drastically, thereby affecting the performance of the overall navigation system. 2. Error Sources: Analysis of Common Measurement Deviations of FOG IMU The errors of FOG IMU can be mainly classified into two types:(1) Angular velocity channel error: This includes installation error, proportional factor error, zero bias error, etc. (2) Acceleration channel error: Mainly caused by installation error, temperature drift and dynamic disturbance. These errors accumulate in the actual environment, seriously affecting the stability and accuracy of the flight control system. 3. Limitations of Traditional Calibration Methods Although traditional static multi-orientation calibration and angular velocity method can partially address the issue of errors, they have obvious shortcomings in the following aspects:(1) Unable to balance accuracy and computational efficiency(2) Inapplicable to full temperature range compensation(3) Dynamic disturbances affect the stability of calibrationThis requires a more intelligent and efficient error modeling and temperature compensation mechanism. 4. Detailed Explanation of the Three-Dimensional Positive and Negative Speed/One-Axis Attitude Calibration Method in the Full Temperature Range (1) Precise Calibration at Multiple Temperature PointsBy setting multiple temperature points ranging from -10°C to 40°C and conducting three-axis rotation calibration at each point, temperature-related error parameters can be collected.(2) Three-Dimensional Positive and Negative Speed Method: Precisely Simulating Real Flight ConditionsUsing a single-axis rate turntable and a high-precision hexahedral tool, positive and negative speed calibration in the X/Y/Z axis directions can be achieved, enhancing the system's adaptability to dynamic environments.(3) One-Axis Attitude Stabilization: Quickly Capturing System Zero OffsetWhile maintaining a static state, initial offsets under different temperatures are recorded to provide precise data support for subsequent error modeling. 5. Piecewise Linear Interpolation (PLI): A Precise Error Compensation Tool with Low Computational Load To meet the error compensation requirements of FOG IMU across the entire temperature range, this paper proposes the Piecewise Linear Interpolation algorithm (PLI), which has the following characteristics:(1) Low computational load: Suitable for embedded navigation systems with limited resources(2) Strong real-time compensation capability: Error is dynamically adjusted with temperature changes(3) Easy to deploy and upgradeCompared with the high-order least squares method, the PLI scheme ensures the compensation accuracy while significantly reducing the system's computational burden, making it suitable for real-time computing scenarios during flight. 6. Practical Verification: Outstanding Performance in Complex Flight Environments Through on-board field experiments, this method significantly enhanced the measurement accuracy and environmental adaptability of the system under various temperatures and dynamic disturbances, providing a solid navigation foundation for subsequent high-performance small rotorcraft flight platforms. 7. Conclusion: Mastering the error modeling and compensation of FOG IMU is the key to building a highly reliable flight platform. With the development of unmanned aerial vehicles and intelligent flight systems, the requirements for the accuracy of navigation systems have become increasingly stringent. By introducing the three-position positive and negative speed calibration and segmented linear interpolation compensation methods, the adaptability and accuracy of FOG IMU in the full temperature range and strong dynamic environment can be significantly improved. In the future, this technology is expected to play a greater role in autonomous driving, robot navigation, and high-precision map collection and other fields. Micro-Magic’s U-F3X80, U-F3X90, U-F3X100,and U-F300 , we can use full-temperature three-way positive and negative rate/one position calibration and PLI compensation method. According to the error characteristics of fiber optic gyro and quartz flexible accelerometer, the FOG inertial measurement unit error model is established, and the three-bit positive and negative rate/one-position calibration scheme is designed at each constant temperature point. The PLI algorithm is used to compensate the zero bias and scale factor temperature errors of the system in real time, reducing the calibration workload and the calculation amount of the compensation algorithm, and improving the system dynamics, temperature environment adaptability and measurement accuracy. U-F3X80 Fiber Optic Gyroscope IMU U-F100A Middle Precision Fiber Optic Gyroscope Based IMU U-F3X100 Fiber Optic Gyroscope IMU U-F3X90 Fiber Optic Gyroscope IMU  

Learn how to reduce magnetic sensitivity in FOG IMUs with advanced techniques like depolarization, magnetic shielding, and error compensation. Discover high-precision solutions for aviation and navigation systems. In high-precision inertial measurement units (IMUs), the fiber optic gyroscope (FOG) is one of the core components, and its performance is crucial for the positioning and attitude perception of the entire system. However, due to the Faraday effect of the optical fiber coil, FOG is extremely sensitive to magnetic field anomalies, which directly leads to the degradation of its zero bias and drift performance, thereby affecting the overall accuracy of the IMU. So, how is the magnetic sensitivity of FOG IMU generated? And how can this influence be effectively suppressed? This article will deeply analyze the technical paths to reduce the magnetic sensitivity of FOG from the perspective of theory to engineering practice. 1. FOG Magnetic Sensitivity: Starting from the Physical Mechanism The reason why FOG is sensitive to magnetic fields lies in the Faraday effect - that is, when linearly polarized light passes through a certain material, under the influence of a magnetic field, its polarization plane will rotate. In the Sagnac ring interference structure of FOG, this rotational effect will cause a phase difference between two beams propagating in opposite directions, thereby leading to measurement errors. In other words, the interference of magnetic fields is not static but dynamically affects the output of FOG in a drifting manner.Theoretically, an axial magnetic field perpendicular to the axis of the optical fiber coil should not trigger the Faraday effect. However, in reality, due to the slight inclination during the winding of the optical fiber, the "axial magnetic effect" is still triggered. This is the fundamental reason why the influence of magnetic fields cannot be ignored in high-precision applications of FOG. 2. Two major technical approaches to reducing FOG magnetic sensitivity (1) Improvements at the optical device level a. Depolarization technology By replacing polarization-preserving fibers with single-mode fibers, the magnetic field response can be reduced. Because single-mode fibers have a weaker response to the Faraday effect, the sensitivity is reduced at the source.b. Advanced winding processControlling the winding tension and reducing residual stress within the fibers can effectively reduce magnetic induction errors. Combined with an automated tension control system, it is the key to improving the consistency of polarization-preserving coils.c. New low-magnetic-sensitivity optical fibersAt present, some manufacturers have launched optical fiber materials with low magnetic response coefficients. When used in combination with ring structures, they can optimize the magnetic anti-interference ability at the material level. (2) System-level Anti-magnetic Measures a. Magnetic Error Modeling and CompensationBy installing magnetic sensors (such as flux gates) to monitor the magnetic field in real time and introducing compensation models in the control system, the output of FOG can be dynamically corrected.b. Multi-layer Magnetic Shielding StructureUsing materials such as μ-alloys to construct double-layer or multi-layer shielding cavities can effectively weaken the influence of external magnetic fields on FOG. Finite element modeling has confirmed that its shielding efficiency can be increased by tens of times, but it also increases the system weight and cost. 3. Experimental Verification: How significant is the influence of magnetic fields? In a set of experiments based on a three-axis turntable, researchers collected the drift data of FOG in both open and closed states. The results showed that when the magnetic field interference was enhanced, the drift amplitude of FOG could increase by 5 to 10 times, and obvious spectral interference signals (such as 12.48Hz, 24.96Hz, etc.) appeared.This further indicates that if no effective measures are taken, the accuracy of FOG will be greatly compromised in actual aviation, space, and other high electromagnetic environments. 4. Practical Recommendations: How to Enhance the Anti-Magnetic Capability of FOG IMU? In practical applications, we recommend the following combination strategies:(1) Select polarization-eliminating FOG structure(2) Use low-magnetic-response optical fibers(3) Introduce optical fiber winding equipment with automatic tension control(4) Install three-dimensional flux gates and build error models(5) Optimize the design of μ-alloy shielding shellsTaking the U-F3X80, U-F3X100 series launched by Micro-Magic as examples, the integrated optical gyroscopes inside them have maintained stable output even in the presence of magnetic interference through multiple technical improvements, making them the preferred solution among current aviation-grade IMUs.  5. Conclusion: Accuracy determines the application level, and magnetic sensitivity must be taken seriously In high-precision positioning, navigation and guidance systems, the performance of FOG IMU determines the reliability of the system. And magnetic sensitivity, as a problem that has been overlooked for a long time, is now becoming one of the "bottlenecks" of accuracy. Only through collaborative optimization from materials, structures to system level can we truly achieve high-precision output of IMU in complex electromagnetic environments. If you are confused about IMU selection or FOG accuracy issues, you might as well rethink from the perspective of magnetic sensitivity. Micro-Magic’s FOG IMU U-F3X80, U-F3X90, U-F3X100,and U-F300 are all composed of fiber optic gyroscopes. In order to improve the accuracy of FOG IMU, we can completely reduce the magnetic sensitivity of the fiber optic gyroscopes inside them by corresponding technical measures. U-F3X80 Fiber Optic Gyroscope IMU U-F3X90 Fiber Optic Gyroscope IMU U-F100A Middle Precision Fiber Optic Gyroscope  U-F3X100 Fiber Optic Gyroscope IMU      

Discover the mid-low precision FOG IMU system: a cost-effective, shock-resistant inertial navigation solution for UAVs, robotics, and marine applications. Learn about its modular design, quick startup, and high stability. In the fields of unmanned systems, intelligent manufacturing, and precise control, the inertial measurement unit (IMU) is becoming a crucial "invisible technology". Today, we will take you to deeply understand a solution that performs well in actual projects - a mid-low precision FOG IMU system designed based on open-loop fiber optic gyroscope (FOG) and MEMS accelerometer.This is not only an inertial sensing device, but also a perfect balance between miniaturization, high cost-effectiveness, and precise navigation. 1. Why Choose FOG IMU? As the traditional platform-based inertial navigation systems are gradually fading from the historical stage, strapdown inertial navigation systems (SINS) have become mainstream relying on mathematical modeling and digital computing.So, what are the core advantages of FOG IMU?(1) Resistance to shock and interference: Fiber optic gyros are naturally shock-resistant and can withstand high G forces, making them particularly suitable for harsh environments.(2) Quick startup: No need for complex initialization; plug and play once powered on.(3) Precise and cost-effective: While meeting navigation requirements, it also controls costs.(4) Easy integration: Small size, low power consumption, and easy embedding.Therefore, it is widely applied in fields such as unmanned aerial vehicles, robots, vehicle-mounted systems, and maritime navigation. 2. Highlights of System Architecture This FOG IMU adopts a modular design, consisting of a three-axis fiber optic gyroscope, a three-axis MEMS accelerometer, a data acquisition module, and a high-speed DSP, supplemented by temperature compensation and error modeling algorithms, to achieve stable output.The six sensitive axes are arranged in three-dimensional orthogonal manner, combined with a software compensation mechanism, to eliminate the influence of structural errors on navigation accuracy.Moreover, this system has also been verified through simulation, ensuring that it still meets the required accuracy for navigation calculations even when using low-precision sensors. 3. Data Acquisition Module: The "Neural Center" of IMU We have specially optimized the data acquisition link:(1) Analog signal conditioning: Two-stage amplification + analog filter, enhancing signal clarity.(2) High-precision ADC sampling: 10ms update cycle, ensuring rapid system response.(3) Temperature compensation channel: Integrated chip and environmental temperature monitoring, achieving full environmental adaptability.This module plays a crucial role in enhancing the overall accuracy of the system. 4. Performance and Real-World Feedback After the prototype deployment and system testing, the performance of this FOG IMU system is as follows:(1) Excellent stability of attitude angles(2) Static errors within the controllable range(3) Strong anti-interference performance, capable of adapting to rapid dynamic changesCurrently, this system has been put into use in a certain type of robot navigation platform, and the feedback is consistent and good. 5. Application Domain Outlook The FOG IMU system is ready to be applied in the following scenarios:(1) Navigation for unmanned aircraft and unmanned vehicles(2) Marine measurement systems(3) Industrial automation equipment(4) Attitude control for low-orbit satellites(5) Intelligent robots and precise positioningIn the future, we will also launch an upgraded version of the FOG IMU tailored for high-precision requirements such as UF-100A. Stay tuned for more updates!   UF100A Middle Precision Fiber Optic Gyroscope Based IMU    

"An in-depth analysis of the testing methods for the bias (zero bias) and scale factor of quartz flexible accelerometers is provided, including specialized techniques such as four-point rolling test and two-point test, as well as the calculation formula for temperature sensitivity. This is applicable to high-precision applications such as inertial navigation and spacecraft."   The bias (zero bias) and scale factor of quartz flexible accelerometers directly determine the measurement accuracy and long-term stability of the accelerometer, especially in high-precision application scenarios such as inertial navigation and attitude control. Therefore, they are two key performance indicators for evaluating quartz accelerometers.   The core significance of bias (zero bias) lies in its inherent system error of the accelerometer, which directly leads to the fundamental deviation of all measurement results. For example, if the zero bias is 1 mg, the measured value will add this error regardless of the actual acceleration. Zero bias will also drift with factors such as time, temperature, and vibration (zero bias stability). In inertial navigation systems, zero drift is continuously amplified through integration operations, resulting in cumulative errors in position and velocity. The temperature characteristics of quartz materials can also cause zero bias to change with temperature (zero bias temperature coefficient), so temperature compensation algorithms are needed to suppress this effect in high-precision applications. Scale factor refers to the proportional relationship between the output signal of an accelerometer and the actual input acceleration. The error in scale factor can directly lead to proportional distortion of the measurement results. The stability of scale factor directly affects system performance in high dynamic range or variable temperature environments. In the acceleration integration operation of inertial navigation, the scale factor error will be integrated twice, further amplifying the position error.   Therefore, the reason why bias and scale factor have become key performance indicators of quartz flexible accelerometers is that they are both fundamental error sources and key constraints on long-term stability. In system level applications, the performance of these two directly determines whether the accelerometer can meet the requirements of high precision and high reliability, especially in scenarios such as unmanned driving, spacecraft, submarine navigation, etc. where there is zero tolerance for errors   The bias test can be conducted through two methods: four point rolling test (0°，90°，180°，270°positions) or two-point test (90°，270°positions). The scale factor test can be conducted through three methods: four point rolling test (0°，90°，180°，270°positions), two-point test (90°，270°positions), and vibration test. Taking the four-point rolling test method as an example, this article explains how to obtain the bias and scale factor of an acceleration sensor.     1. Testing methods for bias and scaling factors:   a) Install the accelerometer on a specific test bench (multi tooth indexing head). b) Start the test bench c) Rotate the test bench clockwise to the 0°position, stabilize it, and record the output of multiple sets of tested products according to the specified sampling frequency. Take the arithmetic mean as the measurement result; d) Rotate the test bench clockwise to the 90°position, stabilize it, and record the output of multiple sets of tested products according to the specified sampling frequency. Take the arithmetic mean as the measurement result; e) Rotate the test bench clockwise to the 180°position, stabilize it, and record the output of multiple sets of tested products according to the specified sampling frequency. Take the arithmetic mean as the measurement result; f) Rotate the test bench clockwise to the 270°position, stabilize it, and record the output of multiple sets of tested products according to the specified sampling frequency. Take the arithmetic mean as the measurement result; g) Rotate the test bench clockwise to the 360°position, then counterclockwise to make the rotation angles at 270°, 180°, 90°, and 0°positions. After stabilization, record the output of multiple sets of tested products according to the specified sampling frequency, and take the arithmetic mean as the measurement result. h) Calculate the bias and scaling factor of the tested product using the following formula (1) and (2). K0 =    -------------------------------------- (1)   K1 =   -------------------------------------- (2)        Where:         K0 -------Bias         K1 -------Scale factor         -------The total average of forward and reverse readings at 0°position         -----The total average reading of forward and reverse rotation at 90°position         --- The total average reading of forward and reverse rotation at180° position         --- The total average of readings for forward and reverse rotation at 270°position   2. Test method for bias temperature sensitivity and scale factor temperature sensitivity a) Start the test bench b) Calculate the bias and scaling factors at each temperature point using the formulas (1) and formulas (2) at room temperature, the upper limit operating temperature specified by the accelerometer, and the lower limit temperature specified by the accelerometer. c) Calculate the temperature sensitivity of the accelerometer using the following formula (3) and (4):      ---------------------(3) where： ---- Bias temperature sensitivity ----Bias of upper limit temperature of sensor ----Bias of sensor room temperature -----Bias of the lower limit temperature of the sensor ------Upper limit temperature ------Room temperature -------Lower limit temperature        ---------------------(4) Where: ----Scale factor temperature sensitivity ------Scale factor ----Scale factor for the upper limit temperature of the sensor ----Scale factor of sensor room temperature -----Scale factor for the lower limit temperature of the sensor ------Upper limit temperature ------Room temperature -------Lower limit temperature AC-1 Quartz Flexible Accelerometer   AC-4 Quartz Flexible Accelerometer  

Electronic compass (also known as digital compass), is through the measurement of the Earth's magnetic field to complete the course calculation, often as a GPS signal or network is not effective supplement. Based on its advantages of small size, low energy consumption, high precision and miniaturization, it is widely used in the field of magnetic heading measurement such as UAV, Marine and automobile. However, in use, the electronic compass also has its own inherent defects: easy to be affected by external magnetic field interference and error, which is the main reason for affecting its measurement accuracy and restricting its application, so it is very necessary to study the method of compensating the measurement error of the electronic compass.   At present, there are many methods to compensate measurement error. For example, the compensation coefficient method is mainly aimed at the dynamic interference during measurement, while the static interference compensation effect is little, and the application range is small. Another example is the adaptive compensation method, which requires the system to achieve high compensation accuracy in the case of linear or low-speed movement, if the system rotates faster, the measurement accuracy will be greatly affected, so the more demanding application scenario makes this method not extensive. At present, if only a single error compensation model is used to compensate the compass error, it can not meet the requirements of the measuring system. In this paper, an error compensation algorithm based on ellipse hypothesis is proposed, which integrates the principle of least squares. The algorithm can realize effective compensation for the measuring error of the electronic compass, and has the characteristics of moderate calculation and wide application. 1.Error analysis of magnetic heading system When the digital compass is installed in the carrier for magnetic heading measurement, its measurement error is caused by a variety of factors, which can be roughly divided into two categories: one is caused by the system's own structure, materials, assembly and other reasons, including compass, installation error, manufacturing error; The other is attitude signal error, although it does not belong to the heading measurement system itself, but it is involved in the calculation of heading parameters, will also cause measurement error. Because the compass error is the most difficult to control and has the greatest influence on the course accuracy, this paper mainly analyzes the compass error. The compass difference is mainly composed of the horizontal component of the hard iron magnetic field and the horizontal component of the soft iron magnetic field of the carrier. A large number of experimental studies show that the error caused by the hard ferromagnetic field on the moving carrier is a periodic error, which can be expressed by formula (1), and its rule is approximately sinusoidal curve; The error caused by the soft iron magnetic field can be expressed by formula (2), and the law changes with the change of the environmental magnetic field.   Where ϕi is the measurement of the heading Angle, and A, B, C, D, and E are error coefficients. Through the error analysis of the compass above, we can see that the total compass of the electronic compass should be the algebraic sum of the above errors. Therefore, combine formulas (1) and (2) to find the total difference ∆ϕ     2.Error compensation by least square method Least Squares (LS) can be used to find the best function match of data by minimizing the sum of squares of errors. It is easy to obtain unknown data and minimize the sum of squares of errors between it and the actual data. The least squares method can also be used for curve fitting and is often used for data optimization.   The least square method can optimize the data fitting in the sense of minimum square variance. It is a mathematical optimization method that can compensate the error caused by the magnetic field interference of the external environment. Under normal circumstances, the measurement error presents a certain periodicity, a more suitable fitting method can be used trigonometric function method, based on the mathematical model of Fourier function, and then corrected according to the heading parameters provided by the standard compass. The following is a brief introduction to the basic principles of least squares.   When a correspondence between two variables y and x needs to be determined based on observations, assuming that they are linear, y at time t can be expressed as:   Where H1,H2,... Hn is n unknown parameters to be determined, x1 (t), x2(t),... xt(t) is a known deterministic function, such as the sine and cosine function of t. Let's say at time t1,t2... tn makes m measurements of y and x, hoping that the variables y and x1 (t), x2(t),... xt(t) to estimate their values. Then formula (4) can be expressed in matrix form: Y =X*H   Using the least squares method, the least squares estimates of the error coefficients A, B, C, D and E shown in formula (3) are obtained from the known azimuth Angle measurement ϕi and azimuth Angle error ∆ϕ. The specific calculation steps are as follows: ① The eight-position error measurement method is adopted. Taking into account the number of samples, the amount of data calculation and the measurement accuracy, eight points with the same Angle interval within the range of heading Angle 360, such as 0, 45, 90, 135, 180, 225, 270 and 315, were taken to conduct heading error test, and 8 sets of data were obtained. ② The error coefficients A, B, C, D and E are obtained according to the principle of least squares. Through the previous analysis, when the error coefficients A, B, C, D and E are calculated by the least square method, the actual course of the carrier after error correction can be calculated by the calculation formula, and the specific research and analysis will not be done here.   3.Summary Micro-Magic company specializes in navigation products, in addition to the least method of error compensation, there are elliptic false method of error compensation and other compensation methods. In the research and development process of electronic compass, it has gradually mature technology and consolidated theoretical foundation. In addition to the continuous optimization of north finding accuracy, there are tilt compensation and other functions, if you are interested in our products, welcome to learn more about our low-cost 2D digital compass C9-C, and 40° tilt compensation - 3D digital compass C90-B and so on, you can contact our professional and technical staff at any time. C9-A High-precision 3 dimension electronic compass with advanced 3D compensation technology C9-B Modbus RTU mode two dimension (2D) electronic compass for unmanned aerial vehicles C9-C high-precision two-dimensional (2D) electronic compass single circuit board measuring azimuth angles from 0 to 360 deg C9-D High-Precision Two-Dimensional (2D) Electronic Compass Single Circuit Board Measuring Azimuth Angles From 0 To 360 Deg    

    Electronic compass has its own unique advantages: the electronic compass itself is small in size, light in weight, the acquisition and solution of azimuth information is real-time, and the output digital signal can make it more direct and convenient in the subsequent use. At present, the development of digital compass sensor technology has been relatively mature, so that it has certain advantages in measurement accuracy and manufacturing cost. Because digital compass is widely used in practice, a large number of high-precision, low-cost electronic compass products suitable for large-scale industrialization need to be put into production.    In today's society, the design and research of navigation and orientation instruments have important value and significance. With the expansion of human exploration in the space field, the stability maintenance, tracking guidance and other functions of artificial satellites, space shuttles, missile weapon systems and various platforms all need the support of navigation orientation technology and corresponding attitude adjustment devices. To sum up, obtaining orientation information and realizing the corresponding attitude control play a fundamental role in various scientific research and engineering realization.   According to the characteristic that the geomagnetic field changes little in a certain time range, it can be considered that the geomagnetic information at the same place is fixed in a short time, and the azimuth information such as heading Angle and attitude Angle can be calculated by the electronic compass according to the geomagnetic intensity information measured.   1.The principle characteristics of the geomagnetic field   As the basic physical quantity of the earth, the geomagnetic field has a direct effect on the physical characteristics of electric and magnetic substances in the earth environment. The characteristics of the Earth magnetic vector field provide a basic coordinate system for azimuth information, and the use of geomagnetic information navigation is stable and reliable, without receiving external information, with good concealment. The geomagnetic field is generated from the structure of the earth itself. There are many magnetic elements and substances in the earth's interior, which produce free flowing electrons under the influence of the extreme environment inside the Earth. These free electrons lead to the improvement of the conductivity between the earth's inner core and outer core, resulting in the flow and movement of free electrons between different strata. This makes the earth as a whole have a stable magnetic field on a macro level, which is equivalent to a magnetic dipole with a constant magnetic field existing in the center of the Earth, resulting in the production of north and south magnetic poles. Figure 1 shows the schematic diagram of the distribution of the Earth's magnetic field. The unit of magnetic induction intensity is Tesla (T), which is Gaussian (Gs) in Gaussian units, and the corresponding relationship between the two is 1T=10-4Gs, the unit system of magnetic field intensity is A/m, and the unit system of magnetic field intensity is Oster (Oe) in Gaussian units, and the corresponding relationship between the two is 1A/m=4π*10-3Oe   The Earth's magnetic field can be classified into basic geomagnetic field, variable geomagnetic field and abnormal geomagnetic field according to the degree of stability. The basic magnetic field covers most of the magnetic field, accounting for more than 90% of the Earth's total magnetic field. The basic type of geomagnetic field can also be divided into dipole-induced magnetic field and non-dipole-induced magnetic field, in which the dipole-induced effect accounts for the main part, the magnetic field comes from the circulation movement of iron and nickel under high temperature and high pressure environment, and the non-dipole is mainly generated by the self-excited motor effect. The basic geomagnetic field itself also changes, but the period of change is very long, so the Earth's magnetic field as a whole can be considered stable. The changing electromagnetic field is generated in the ionosphere and magnetosphere of the earth, and the magnetic field disturbance is mainly related to the solar change, and the changing electromagnetic field can be divided into stable change and interference change. Quiet changes occur on the solar or lunar calendar and are mainly caused by solar electromagnetic radiation or particle radiation. The phenomenon of magnetic storm is the phenomenon of geomagnetic interference in large space, the main effect of which is the strong change of the ground vector component of geomagnetic field. The abnormal geomagnetic field comes from the ferromagnetic properties of ferromagnetic materials and can be regarded as the constant vector addition on the stable geomagnetic field.   2.Error analysis of electronic compass   Deviation of electronic compass, also known as compass deviation, is the error of measurement results caused by ferromagnetic interference in the nearby environment when the compass is working. The deviation between the measurement results and the real value is even tens of degrees without corresponding compensation link, which is because the magnetic field strength of the earth magnetic field is weak, and the magnetic field strength is only 0.5-0.6 gauss. Therefore, the measurement results of digital compass are very easy to introduce the interference caused by environmental ferromagnetic factors, and the compass has become the main source of error of electronic compass.   Compass can also be divided into hard iron interference and soft iron interference, hard iron interference is caused by permanent magnetic objects or magnetized objects, with a permanent magnetic material under the influence of the external magnetic field, the overall magnetic moment of the object is no longer zero, thus showing magnetism. The magnetic field strength generated by it can be regarded as constant and unchanged in a certain time range, and this permanent magnetic material still maintains a relatively stable residual magnetic field strength after the magnetization effect, even after the external magnetic field action is removed. To sum up, the position and intensity of the interference effect on the compass can be considered as a fixed and constant stabilizing effect, and the compensation means for it is relatively easy to realize.   Summary     Micro-Magic company for aerospace, mining drilling and other engineering projects to provide tools and technical support, the current electronic compass series, C9000-A,C9000-B,C9000-C,C9000-D and other products, with soft magnetic, hard magnetic compensation function, it plays an important role in improving the north finding accuracy. If you want to understand the information of digital compass, you can always communicate with our professionals. C9000-A Tilt Compensated Magnetic Compass Sensor 3 Axis Magnetic Heading Yaw Angle Meter C9000-B High-precision all attitude 3D electronic compass board using advanced hard and soft iron calibration algorithms digital output C9000-C Fluxgate Compass Gyro Compensated Compass 6 Axis Compass Electronic Yaw Heading Sensor C9000-D High Performance Heading Sensor for Antenna Tower Azimuth Finding Low Cost Azimuth Angle Sensor Measure Tower Heading Angle  

Key Points   Product: Electronic Compass (C9000-B and other variants)Features:• Utilizes three-dimensional magneto-resistive sensors for geomagnetic field measurement• Incorporates an accelerometer for static stability and inclination compensation• Uses Kalman filtering algorithm for noise reduction and optimal state estimation• Provides digital output signal for direct integration with control systemsAdvantages:• High accuracy and stability, suitable for dynamic environments• Low energy consumption, compact size, and lightweight• Anti-shaking and anti-vibration, ideal for aviation, robotics, autonomous vehicles, and navigation systems• Capable of compensating for hard and soft magnetic interference• Can be integrated into control loops for applications like autonomous navigation or equipment maintenance Electronic compasses, also called digital compasses, are a method of using the Earth's magnetic field to determine the North Pole, and have been widely used as navigation instruments or attitude sensors. In ancient times, it was called compass, and the magneto-resistance sensor produced by modern advanced processing technology provides a powerful help for the digitalization of compass. Nowadays, electronic compasses are generally machined from chips such as magneto-resistive sensors or fluxgates. It can be used in horizontal and vertical hole measurement, underwater exploration, aircraft navigation, scientific research, education and training, building positioning, equipment maintenance, navigation system and other fields.   Compared with the traditional pointer type and balance frame structure compass, the digital compass has low energy consumption, small size, light weight, high precision and miniaturization. Its output signal can be digitally displayed through processing. It can not only be used for pointing, but also the digital signal can be directly sent to the automatic rudder to control the ship's operation. At present, the three-axis strap-down magnetic resistance digital magnetic compass is widely used. This kind of compass has the advantages of anti-shaking and anti-vibration, high heading accuracy, electronic compensation for interference field, and can be integrated into the control loop for data link, so it is widely used in aviation, aerospace, robotics, navigation, vehicle autonomous navigation and other fields.   1.The constitution of an electronic compass The three-dimensional electronic compass C9000-B is composed of a three-dimensional reluctance sensor, an inclination sensor and an MCU. The 3D magneto-resistive sensor is used to measure the earth's magnetic field, and the inclination sensor is used to compensate the non-horizontal state of the magnetometer. The MCU processes signals from magnetometers and tilt sensors as well as data output and soft and hard iron compensation. The magnetometer is based on three vertical magneto-resistive sensors, each axial sensor detects the strength of the geomagnetic field in that direction.     The sensor in the forward direction called the x direction detects the vector value of the geomagnetic field in the x direction, and the sensor in the right or Y direction detects the vector value of the geomagnetic field in the Y direction. Sensors in the down or Z direction detect the vector value of the Earth's magnetic field in the Z direction.   The sensitivity of the sensors in each direction has been adjusted to the optimum point based on the component vector of the geomagnetic field in that direction and has very low cross-axis sensitivity. The analog output signal generated by the sensor is amplified and sent to MCU for processing.   2.The following part of the hardware and principles are introduced 1)Magnetometer: Since the geomagnetic field is a vector, at a certain point, this vector can be broken down into two components parallel to the local level and one component perpendicular to the local level. So if you keep the compass module parallel to the local level the three axes of the magnetometer correspond to these three components. At present, the module is parallel to the horizontal plane by the Angle compensation, and then the heading Angle is calculated by the compensated data.   2) Accelerometer: The acceleration can be calculated from the three-axis data, which has advantages in static stability.   3)Kalman filtering is an algorithm that optimally estimates the state of a system by using linear system state equation and observing system input and output data. Since the observation data includes the effects of noise and interference in the system, the optimal estimation can also be regarded as a filtering process.   In radar, for example, one is interested in tracking a target, but measurements of the target's position, speed, and acceleration are often noisy at all times. Kalman filter uses the dynamic information of the target, tries to remove the influence of noise, and gets a good estimate of the target position. This estimate can be an estimate of the current target location (filtering), an estimate of the future location (prediction), or an estimate of the past location (interpolation or smoothing).   Summary In addition to the three-axis electronic compass, Micro-Magic company has a wealth of electronic compass types, such as low-cost two-axis electronic compass C9000-B, high-precision two-axis electronic compass C9000-D, etc., they have been strictly tested, in extremely harsh environments can also provide accurate course data. If you have the need for digital compass, freely to contact us. C9000-B High-precision all attitude 3D electronic compass board using advanced hard and soft iron calibration algorithms digital output   C9000-D High Performance Heading Sensor for Antenna Tower Azimuth Finding Low Cost Azimuth Angle Sensor Measure Tower Heading Angle