Indispensable components for DIY drones

 

The cost-effective choice of drone sensors: revealing the secrets of high-performance nine-axis IMU

Sensors are an important part of drones and are the key to drone navigation, stable control and precise flight.

Gyroscopes and accelerometers provide carrier angular velocity and acceleration, which can be used to calculate attitude, speed, displacement and other information. Magnetometers can provide magnetic north direction.

Our IMU ER-MIMU-07 is a nine-axis IMU that integrates these three high-performance sensors. It is small in size and light in weight while ensuring performance, making it very suitable for drones.

**Lower price, higher performance**

Simplify and reduce design costs while maintaining high performance. Lower price than STIM300, but higher performance.

**Attitude control**

Gyroscope measurement range is 400º/s, bias instability is 0.3 º/h. Accelerometer bias stability is 50ug, bias repeatability is 100ug.

It can detect changes in the attitude of the drone in real time, quickly respond to any unreasonable attitude changes, and stabilize the drone.

**Navigation**

Combined with other sensor data, it can help determine the position and direction of the drone for navigation.

The volume is only 38.6x 44.8 x25.5mm, the weight is ≤70g, and the compact and small design can be easily installed on the fuselage of the drone.

**Widely applied**

In addition to drones, it can also be applied to other unmanned systems, such as autonomous driving of unmanned vehicles, unmanned ships USV and underwater vehicles UAV.

If you are interested in this and would like to know its data sheet.

You can click on links. Ask directly at bottom of page (please indicate your source): https://www.ericcointernational.com/inertial-measurement-units/mems-inertial-measurement-unit/er-711-mems-inertial-measurement-unit.html

You can also take a screenshot and send it directly to this email address: 

 ericco188@ericcointernational.com

An IMU designed specifically for drones, with multiple sensors integrated

 

Sensors are the core components of drone flight control systems, which can help drones achieve multiple functions such as attitude control, navigation, flight control, etc.

A basic drone needs to have characteristics such as stability, accuracy, low power consumption, and environmental perception. We currently have an IMU ER-MIMU-16 that perfectly meets these requirements.

**Multiple high-performance sensor integration**

Most IMUs only have built-in gyroscopes and accelerometers. Our IMU integrates sensors such as gyroscopes, accelerometers, magnetometers, and barometers (altimeters), which are very suitable for drones.

Gyroscope: dynamic measurement range: ±450º/s, bias instability :0.3º/h;

Accelerometer: dynamic measurement range: ±30g, bias instability: 10ug;

Gyroscopes and accelerometers provide the angular velocity and acceleration of the drone. These data can be calculated to obtain information such as the drone's attitude, speed, and displacement.

Magnetometer: dynamic measurement range ±2.5Gauss, can measure the strength and direction of the magnetic field, and provide the magnetic north direction.

Barometer: pressure range 450~1100mbar, by measuring atmospheric pressure, the data provided can assist the drone in navigation, rise to the required height, and accurately estimate the ascent and descent speeds.

**Lightweight design, easy to install**

This IMU has a volume of 47×44×14mm, a thickness of only 14mm, and a weight of 50g. It can be easily installed in various drones.

**SPI communication interface**

This type of communication method has a high data transmission rate and can perform high-speed data communication. It can also send and receive data at the same time, doubling the efficiency.

If you are interested in this and would like to know its data and price

You can click to view detailed information and then send an email inquiry：https://www.ericcointernational.com/inertial-measurement-units/low-cost-inertial-measurement-unit.html

You can also take a screenshot and click on the email to ask for detailed information immediately： ericco188@ericcointernational.com 

The integrated navigation: escorting safe flight of drones

 The integrated navigation: escorting safe flight of drones

GNSS systems (such as GPS, GLONASS, BDS, etc.) provide positioning services with global coverage, but the signals may be blocked or interfered with. They are usually combined with inertial navigation systems to form the integrated navigation system, which can be used in various unmanned systems.

At present, integrated navigation has been widely used in UAVs. It can perform positioning and orientation, and provide attitude, heading and altitude information to the flight control system of the UAV.

The flight control system combines other sensor information to achieve automatic flight, and can also use the combined attitude information to achieve fuselage attitude stability.

We have an integrated navigation system ER-GNSS/MINS-05, which is the most cost-effective one. It has high reliability and is reasonably priced.

1. The product has highly reliable and low-cost MEMS gyroscopes (bias instability <2°/h) and accelerometers (bias instability <24ug).

2. The integrated navigation information provided has roll and pitch accuracy up to 0.1°, post-processing 0.03°, heading 0.1°, post-processing 0.05°, and speed accuracy up to 0.03m/s.

3. Built-in full-band full-system dual-antenna positioning and orientation GNSS module. Single antenna can perform high-precision positioning and speed measurement. Dual antennas can be quickly oriented and can provide high-precision heading and attitude information, which is crucial for applications such as drones and ship navigation.

4. It also has a variety of data interfaces, easy installation, and supports RS422/RS232 and CAN. It is sufficient to meet applications in most cases.

5. It can be widely used in land, aviation, navigation and other fields, including but not limited to autonomous driving, precision agriculture, drones, unmanned surface vehicles, etc.

You can click to view detailed information and then send an email inquiry：  https://www.ericcointernational.com/inertial-navigation-system/mems-inertial-navigation-system/cost-efficient-gnss-aided-mems-ins.html

Email: ericco188@ericcointernational.com 

 

Choose a suitable IMU to make your drone flight more stable and safe

 

       As one of the core components of drones, IMU plays an irreplaceable role. Its high precision, fast response and freedom from external interference enable drones to maintain stable and precise flight and accurate navigation and positioning in complex environments, and can also perform fault diagnosis for drones. ERICCO's MEMS IMU can achieve high performance while being small in size and light in weight, making it very suitable for drones.

We have a tactical-grade IMU ER-MIMU-M02, which is low-cost and has an advantage in price. It is a 10-axis IMU with an added three-axis magnetometer and barometer (altimeter). It is only 47×44×14mm in size and weighs 50g. Compared with other IMUs, it is more suitable for drones.

The built-in accelerometer of the IMU cannot be used to detect absolute heading (yaw). The magnetometer in this IMU measures the magnetic field strength in three dimensions, which can help determine the heading of the object as well as roll and pitch, and correct the integrated error of the yaw gyroscope in the sensor fusion algorithm.

The barometer measures the atmospheric pressure and calculates the altitude of the drone, which is crucial for the safe flight of the drone!

The dynamic measurement range of the built-in gyroscope is ±450º/s, the bias instability is 2 º/h, and the angular random walk is 0.08º/√h. The dynamic measurement range of the accelerometer is 16g, the bias stability is 0.1mg (Allen variance), and the angular random walk is 0.02m/s√h.

Considering the flight time requirements of drones, this IMU has a power of only 1.5W, which can extend the flight time of drones.

This IMU has a short production cycle and can be mass-produced, which is particularly suitable for users with large demands and limited budgets.

If you are interested in this and want to know more, please follow me and send me a message, I will reply immediately. I will update the relevant content later.

Email: ericco188@ericcointernational.com  

Wechat: 18992836912

Do you know what can make drone flights more stable, safer and more widely used?

The key to achieving autonomous navigation, stable control and precise flight of drones is closely related to IMU, which is one of the core technologies of drone systems. At present, there are also research teams that have developed IMU-centric data-driven diagnostic methods to perform fault diagnosis on drones without the need for additional sensors. Choosing the right IMU can make flight more stable and safer.

ERICCO's MEMS IMU ER-MIMU-07 and ER-MIMU-03 (OEM customization is available) can be used in drones. Using MEMS technology, they are small in size, superior in performance, light in weight, low in power consumption, and cost-effective, and are very popular among users.

Drones have strict requirements on the size and weight of IMUs. The ER-MIMU-03 has a size of (43.2×43.2×35.5mm (without shell), 65×70×45.5mm (with shell)) and a weight of (≤100g (without shell), ≤220g (with shell)).

The ER-MIMU-07 is a very small IMU, measuring only 38.6 x 44.8 x25.5mm and weighing less than 70g, which is suitable for drones with higher IMU requirements.

Flight control of drones is one of their most basic functions. MEMS IMU helps drones maintain a stable attitude by providing real-time acceleration and angular velocity data.

The gyroscope measurement range of ER-MIMU-03 and ER-MIMU-07 is ±400deg/s, bias instability <0.3deg/hr, angular velocity random walk <0.15°/√h, accelerometer bias repeatability 5mg, and second-order nonlinear coefficient <100μg/g2. At the same time, it has the characteristics of low power consumption, which prolongs the flight time of drones.

It can also combine data from other sensors (such as GPS, magnetometer, etc.) to calculate the precise location and attitude information of the drone for navigation and positioning. When the drone is taking aerial photos, it can maintain extremely high stability to ensure the clarity and stability of the images and videos taken. At the same time, it can also be used as part of the drone's fault safety system to detect abnormal movements or attitude changes and trigger automatic recovery procedures or emergency landing procedures to protect the safety of the drone and the surrounding environment.

In the design and application of drones, high-performance IMUs are able to provide stable and accurate data under various environmental conditions, such as temperature changes, vibrations, and rapid movements, and perform precise tasks such as aerial photography, logistics transportation, and agricultural monitoring.

MEMS IMU has many applications in the field of drones. They not only improve the performance and stability of drones, but also expand the scope of application of drones. If you are interested in this and want to know more, please follow me and send me a message. I will reply immediately. I will update the relevant content later.

Email: ericco188@ericcointernational.com  

Wechat: 18992836912

Application of high-precision inertial navigation IMU module in surveying and mapping

With the rapid development of science and technology, high-precision inertial navigation IMU modules are increasingly used in the field of surveying and mapping. This advanced technology not only improves the accuracy and efficiency of surveying and mapping, but also greatly promotes the development of surveying and mapping science.

First of all, one of the main applications of high-precision inertial navigation IMU modules in surveying and mapping is aerial surveying and mapping. Aerial surveying and mapping play an important role in geographic information systems (GIS), and high-precision inertial navigation IMU modules can provide important data such as aircraft attitude, position and speed information. By carrying this module, aerial surveying and mapping can achieve high-precision positioning and three-dimensional modeling of the earth's surface, providing reliable data support for urban planning, traffic management, environmental protection and other fields.

Secondly, high-precision inertial navigation IMU modules are also widely used in ground surveying and mapping. Ground surveying and mapping are mainly used for drawing maps, measuring surface morphology and surveying regional resources. The high-precision inertial navigation module IMU can obtain the position coordinates, attitude angle, speed and other information of the measurement vehicle in real time, thereby improving the accuracy and reliability of surveying and mapping data. Whether it is road surveying in urban construction planning, or land surveying and resource assessment, high-precision inertial navigation IMU modules can play an important role.

In addition to being widely used in two-dimensional surveying and mapping, high-precision inertial navigation IMU modules can also play an important role in three-dimensional surveying and mapping. With the continuous advancement of 3D technology, people's demand for 3D models of landforms, buildings, resources, etc. is increasing. The high-precision inertial navigation IMU module can provide precise position and attitude data for three-dimensional surveying and mapping, thereby achieving high-precision three-dimensional modeling of complex landforms and buildings. This has played an important role in promoting urban planning, architectural design, cultural relics protection and other fields.

In addition to the above application fields, high-precision inertial navigation IMU modules also play an important role in ocean surveying and mapping. Marine surveying and mapping is mainly used for seabed landform survey, marine resource assessment and navigation safety. The inertial navigation IMU module can cooperate with equipment such as sonar depth sounders to provide accurate position and attitude information of the ship for accurate charting and research on seabed landforms. In engineering fields such as submarine pipelines and offshore oil development, high-precision inertial navigation IMU modules can also provide reliable data support for engineering surveying and mapping.

The ER-MIMU-01 and ER-MIMU-05 developed by Ericco use high-quality and reliable MEMS accelerometers and gyroscopes. RS422 communicates with the outside. The baud rate can be flexibly set between 9600~921600, and the user needs to be set through the communication protocol. communication baud rate. Equipped with X, Y, Z three-axis precision gyroscope, X, Y, Z three-axis accelerometer, with high resolution, it can output the original hexadecimal complement of X, Y, Z three-axis gyroscope and accelerometer through RS422 code data (including gyroscope hexadecimal complement) numerical temperature, angle, accelerometer hexadecimal temperature, acceleration hexadecimal complement); it can also output gyroscope and accelerometer data that have been processed by underlying calculations Floating point dimensionless values, whether it is aviation, ground or ocean surveying and mapping, can achieve a more accurate and efficient surveying and mapping process through the high-precision inertial navigation IMU module. If you want to know more about IMU products, you can click on the link below to learn more.

Web:https://www.ericcointernational.com/inertial-measurement-units

Email: info@ericcointernational.com

Whatsapp: 13630231561

WeChat：13992884879

How to choose the right IMU?

Choosing the right product is not an easy task and we need to consider many aspects. Some of the aspects we have to consider when choosing an IMU are performance, underlying technology, SWaP (size, weight and power) and cost.

Additionally, another important factor for drones is the robustness of the IMU. In harsh drone applications, vibrations can reach very high levels and varying temperatures. Therefore, a drone’s IMU needs to be highly rugged to withstand harsh environments.

Advantages of having the right inertial measurement device

Rigorous applications such as drones require extremely stable and high-performance IMUs. An IMU with good performance, vibration robustness, and temperature stability will improve UAV flight operations. Accurate steering is easier to achieve even in high-vibration situations. In order to meet the requirements of UAV equipment, the ER-MG2-300/400 gyroscope placed in ER-MIM-02 not only adopts an advanced differential sensor design, it can eliminate the influence of linear acceleration and survive the impact in extremely harsh environments. It operates under vibration conditions and has a measurement range of 400 degrees/second and a deviation instability of 0.01°/hour. Able to measure angular velocity up to ±400°/s and has a digital output protocol compliant with Mode 3 SPI. Angular rate data is represented as 24-bit words. If you are interested in our products, please click the link below to learn more.

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More information:

Web:

https://www.ericcointernational.com/inertial-measurement

Email: info@ericcointernational.com

Whatsapp: 13630231561

How to choose an inertial measurement unit (IMU) for your drone application?

An inertial measurement unit (IMU) is an electronic device that uses accelerometers and gyroscopes to measure acceleration and rotation and can be used to provide position data.

IMUs are an important component of unmanned aerial systems (UAVs, UAS, and drones) and common applications include control and stabilization, guidance and correction, measurement and testing, and mobile mapping.

Raw measurements output from an IMU (angular rate, linear acceleration, and magnetic field strength) or AHRS (roll, pitch, and yaw) can be fed into devices such as an inertial navigation system (INS) to calculate relative position, direction, and speed to help UAV navigation and control.

There are many types of IMUs, some of which incorporate magnetometers to measure magnetic field strength, but the four main technology categories for drone applications are: silicon MEMS (microelectromechanical systems), quartz MEMS, FOG (fiber optic gyroscopes), and RLG (Ring Laser Gyroscope).

Silicon MEMS IMUs are based on tiny sensors that measure the deflection of a mass due to motion, or the force required to hold the mass in place. They typically have higher noise, vibration sensitivity, and instability parameters than FOG IMUs, but as technology continues to advance, MEMS-based IMUs are becoming more accurate.

MEMS IMUs are well suited for small UAV platforms and high-volume production units because they can often be manufactured at smaller size and weight and at lower cost.

The FOG IMU uses solid-state technology based on a beam of light propagated through a coiled optical fiber. They are less sensitive to shock and vibration and have excellent thermal stability, but are susceptible to magnetic field interference. They also offer high performance in important parameters such as angular random walk, bias offset error and bias instability, making them ideal for mission-critical UAV applications such as extremely precise navigation.

The higher bandwidth also makes the FOG IMU suitable for high-speed platforms and stable. They are larger and more expensive than MEMS-based IMUs and are typically used on large UAV platforms.

The RLG IMU uses a similar technical principle to the FOG IMU, but uses a sealed ring cavity instead of an optical fiber. They are generally considered the most accurate option, but are also the most expensive IMU technology and are often much larger than alternatives.

Quartz MEMS IMUs use a one-piece inertial sensing element micromachined from quartz, driven by an oscillator to vibrate at precise amplitudes. The vibrating quartz can then be used to sense angular rate, producing a signal that can be amplified and converted into a DC signal proportional to the angular rate. These factors make it ideal for inertial systems designed for space- and power-constrained UAV environments.

More information:

Website: https://www.ericcointernational.com/inertial-measurement-units

Email: info@ericcointernational.com

WeChat: 13630231561

How to correct when there is an error in the inertial device？

 An inertial measurement unit (IMU) is an electronic device that uses accelerometers and gyroscopes to measure acceleration and rotation and can be used to provide position data.

So today we will learn how to correct the error of the inertial device?

The following are some calibration methods for reference only.

Calibration method

(1) Calibration of internal parameter error of inertial device

(2) Discrete liquid level calibration

(3) Semi-system level calibration

(4) System level calibration

Comparison of different types of calibration methods

(1) The discrete-level calibration accuracy is higher, but it depends on the turntable.

(2) The calibration accuracy at the semi-system level is the worst, but it does not rely on a turntable, has low cost and high efficiency, and meets the calibration requirements of MEMS.

(3) System-level calibration has the highest accuracy, but it is only suitable for high-precision inertial navigation calibration.

Then the ER-MIMU-01 developed by Ericco uses high-quality and reliable MEMS accelerometers and gyroscopes. It communicates with the outside through RS422. The baud rate can be flexibly set between 9600~921600. The communication baud rate required by the user can be set through the communication protocol. . Equipped with X, Y, Z three-axis precision gyroscope, X, Y, Z three-axis accelerometer, with high resolution, it can output the original hexadecimal complement of X, Y, Z three-axis gyroscope and accelerometer through RS422 code data (including gyroscope hexadecimal complement) numerical temperature, angle, accelerometer hexadecimal temperature, acceleration hexadecimal complement); it can also output gyroscope and accelerometer data that have been processed by underlying calculations Floating point dimensionless value.

If you want to know more about IMU or are interested in the product, you can click the link below, send an email for consultation or leave your Whatsapp account, and we will contact you.

Web: 

https://www.ericcointernational.com/inertial-measurement-units

Email: info@ericcointernational.com

Whatsapp: 13630231561

Do you know how wide the application fields of MEMS IMU are?

The full name of IMU is inertial measurement unit, so how much do you know about IMU? First of all, we know that imu is composed of three single-axis accelerometers and three single-axis gyroscopes. The accelerometer detects the acceleration signal of the object in three independent axes of the carrier coordinate system. The gyroscope detects the angular velocity signal of the carrier relative to the navigation coordinate system. For After processing these signals, the attitude of the object can be obtained. calculated.

         Secondly, I would like to share with you some areas where MEMS IMU can be applied. Its application areas are quite extensive. I hope it can help you. The following are the areas where imu can be applied:

North seeking in logging tools/gyro tools

Pointing, steering and guiding in advanced mining/drilling equipment

Initial alignment in weapon/UAV launch systems

Direction pointing and tracking in satellite antenna, target tracking system

Guidance and navigation in navigation grade MEMS weapon system

Orientating and positioning in railway train system

Precision platform attitude measuring and controls

Precision attitude, position measuring in navigation grade MEMS IMU/INS

North finding and positioning in land surveying/land mobile mapping system

Petroleum exploration

Bridge, tall building, tower, dam monitoring

Rock and soil monitoring

Mining

More information:

Web: https://www.ericcointernational.com/inertial-measurement-units

Email: ericco741@163.com

Whatsapp: 13630231561

Wechat: 13992884879

How is IMU used?

 The concept of IMU

 

The inertial measurement unit, referred to as IMU, is a device that measures the three-axis attitude angle (or angular velocity core) and acceleration of an object. Gyroscopes and speedometers are devices of an inertial navigation system.

With the built-in speed sensor and gyroscope, the IMU can measure linear acceleration and rotational angular velocity from three directions, and can obtain information such as the vehicle's attitude, speed, and torsion through calculation.

IMU working principle

 

The IMU is a module composed of various sensors such as a three-axis accelerometer, a three-axis gyroscope, and a three-axis magnetometer.

1. The working principle of three-axis accelerometer

 

Most three-axis acceleration sensors use piezoresistive, piezoelectric and capacitive working principles. The acceleration generated is proportional to changes in resistance, voltage and capacitance, and is collected through corresponding amplification and filtering circuits. This is based on the same principle as the ordinary acceleration sensor, so with certain technology, three single axes can be turned into a three-axis. For most sensor applications, two-axis acceleration sensors can already meet most applications.

2. The working principle of three-axis gyroscope

 

The working principle of the three-axis gyroscope is based on the gyroscopic effect. When the gyroscope's axis of rotation is perpendicular to the direction of a force, it will feel the effect of the force, thereby generating a torque that causes it to rotate in the coordinate system. The three gyroscopes in the three-axis gyroscope are installed on three mutually perpendicular axes. They sense the angular velocity on the x, y, and z axes respectively, and output the signals to the relevant circuits for processing.

3. The working principle of three-axis magnetometer

 

The magnetometer uses three mutually perpendicular magnetoresistive sensors. The sensor in each axis detects the strength of the geomagnetic field in that direction. For example, alloy materials with some crystal structures. They are very sensitive to external magnetic fields, and changes in the strength of the magnetic field will cause changes in the resistance value of the magnetoresistive sensor. In addition, the three-axis magnetometer can also use the Lorentz force principle. The current flows through the magnetic field to generate force, thereby driving changes in capacitance and so on.

Application of high performance quartz accelerometer

 

Inertial navigation IMU has a wide range of application scenarios and is often used for pointing, steering and guidance in advanced mining/drilling equipment, ships, automobiles, drones, robots, oil exploration, bridge exploration, high-rise buildings, iron towers, dam monitoring, rock Soil monitoring, navigation and positioning of transportation vehicles such as mining and missiles, and north-finding positioning in geodetic/land mobile mapping systems.

 In the aviation field, inertial navigation IMU can realize motion control of aircraft such as climbing, descending, turning and taxiing, improving flight safety and accuracy.

In the automotive field, inertial navigation IMU can help vehicles achieve autonomous driving and traffic jam identification, improving driving performance and safety.

https://www.ericcointernational.com/inertial-measurement-units

What is the use of imu?

IMUs are often included in inertial navigation systems that use raw IMU measurements to calculate orientation, angular velocities, linear velocity, and position relative to a global reference frame. IMU-equipped INS form the basis for navigation and control of many commercial and military vehicles such as manned aircraft, missiles, ships, submarines and satellites. IMUs are also important command and control components for unmanned systems such as UAVs, UGVs and UUVs. Simpler versions of INS, called attitude and heading systems, use the IMU to calculate the vehicle's heading position relative to magnetic north. Data collected from the IMU sensors allows the computer to track the ship's position using a method known as dead reckoning.https://www.ericcointernational.com/inertial-measurement-units

In land vehicles, the IMU can be integrated into GPS-based automotive navigation systems or vehicle tracking systems, giving the system dead-reckoning capabilities and the ability to collect as much accurate data as possible about the vehicle's current speed, turn rate, heading, and lean. and acceleration in combination with the vehicle's wheel speed sensor output and, if available, the reverse signal, for purposes such as better traffic accident analysis.

In addition to navigation purposes, IMUs serve as orientation sensors in many consumer products. Almost all smartphones and tablets contain IMUs as orientation sensors. Fitness trackers and other wearable devices may also include IMUs to measure movements such as running. IMUs also have the ability to detect people's developmental levels during movement, determining the specificity and sensitivity of specific running-related parameters. Some gaming systems, such as remote controls for the Nintendo Wii, use the IMU to measure motion. Low-cost IMUs have fueled the rapid growth of the consumer drone industry. They are also often used in sports technology (technical training)[4] and animation applications. It is a competing technology for use in motion capture technology.[5] The IMU is at the heart of the balancing technology used in the Segway personal transporter.

https://www.ericcointernational.com/inertial-measurement-units

How does Inertial Positioning Solve the Problem of Gyroscope Drift and Magnetic Field Interference?

In order to solve the problems of integral error and magnetic field interference of gyroscope and electronic compass in attitude calculation of navigation system, a fusion algorithm of Kalman filter and complementary filter was proposed. First, the electronic compass and gyroscope are obtained through the Kalman filter to obtain the optimally estimated quaternion. Then, the complementary filtering algorithm is used to compensate for the drift of the gyroscope to obtain the corrected quaternion. Then, the obtained quaternion and Kalman filters are used to obtain the optimally estimated quaternion, and the second optimal estimation of the quaternion is conducted through the Kalman filter. Then output attitude Angle. The results of the proposed algorithm, the complementary filtering algorithm, and the non-filtering algorithm are compared in the experiment. Experiments show that the algorithm can not only effectively solve the divergence of azimuth error, but also effectively solve the magnetic field interference, and achieve high precision azimuth output.

For more info Ericco Gyro Sensor.

With the development of miniaturized inertial devices represented by MEMS (Micro-Electromechanical Systems) sensors, the inertial positioning technology based on strapdown inertial navigation principle and MEMS sensors is increasingly paid attention to. Especially in indoor, underground, mine, underwater, battlefield, and other occasions where satellite signals are difficult to receive [1].In view of the above problems, the electronic compass is often used to correct the gyro. In the indoor, underground, mine, underwater, and other processes, the magnetometer is more prone to interference, resulting in greater deviation of orientation. To solve the problems of magnetometer vulnerable to interference and gyro integral drift, there have been numerous fusion algorithms, such as Kalman filter, untracked Kalman filter (UKF), extended Kalman filter (EKF), etc. [2-4]. These filtering methods need to establish accurate state equations and observation equations. There is another filtering algorithm that extends on the basis of complementary filterings, such as classical complementary filtering and complementary filtering algorithm based on gradient descent method [3-6]. However, the accuracy of this filtering algorithm is not high. Face these problems, this paper proposes an inertial positioning algorithm of Kalman filtering and complementary filtering fusion, the algorithm in the design of Kalman filter, the accelerometer and magnetometer fusion of quaternion as observed value, using the gyroscope of a quaternion as a status value, through the data fusion filtering, complete the quaternion optimal estimate for the first time, For the gyro drift problem, the designed complementary filter is used to compensate the gyro drift, and the corrected angular velocity is obtained, and then the continuously updated quaternion after correction is obtained. Then, the optimal estimation quaternion completed at the first time is estimated through the second Kalman filter, and then the high-precision attitude angle is output.

If interested, pls contact us: info@ericcointernational.com.

How to use IMU (inertial measurement unit )in pipeline 3D attitude measuring ?

Inertial navigation is an inertial measurement unit (IMU) composed of a gyroscope and an acceleration sensor to measure angular velocity and acceleration information of the carrier.Based on the inertial measurement principle, the pipeline attitude measuring instrument introduced in this paper measures its own three-axis attitude Angle or angular velocity, current acceleration, etc., and analyzes and calculates these attitude quantities, so as to obtain the three-dimensional attitude of the pipeline.

.Let's take a look a measuring instrument based on inertial measurement sensor technology -- pipeline three-dimensional attitude measuring instrument.

As a common instrument for measuring the precise attitude (trajectory) of underground pipelines, the pipeline attitude measuring instrument is a kind of three-dimensional precise attitude measuring instrument based on MEMS inertial measurement unit.This kind of product has internal integration of inertial guided measurement unit, lithium battery, DSP and mass storage unit, which can complete the collection without external auxiliary equipment. It adopts all-metal sealing structure and adaptive shrinkage guide device, which can adapt to the traction and travel of various inner diameter pipelines. It is shockproof and always keeps the measuring unit on the center line of the pipeline.It is mainly applied to the completion measurement of pipe jacking construction in trenchless industries of underground pipelines such as electric power, gas and water.

In the process of use, the pipeline attitude measuring instrument can measure its own three-axis attitude Angle or angular velocity, current acceleration and travel distance through the inertial measurement sensor device. These attitude values are analyzed and calculated by the integral algorithm, so as to obtain the three-dimensional attitude of the pipeline.In complex urban environment, this kind of instrument can accurately measure the three-dimensional data of underground pipeline, which is especially suitable for the measurement and positioning of pipeline completion.

At present, the existing pipe network and well chamber detection technology includes ground detection and underground detection. Ground detection is mainly carried out by radar, infrared ray and ultrasonic methods for line finding and flaw detection.Although the detection is conducted directly on the surface, the detection efficiency is low and the detection accuracy cannot be guaranteed. At the same time, there are certain requirements for the technical level of the detection personnel and the cost of the detection equipment is also relatively expensive.Underground detection technology consists of laser radar, closed-circuit television, downhole robot: although laser radar theory can more accurate detection of pipe network, but to the well chamber test is difficult, expensive equipment at the same time, inconvenience, for operating and testing personnel requirements are high, the result is not intuitive, practicality is not high.

For trenchless pipeline of accurate location information in pipeline construction, the scientific use of underground space, the maximum to avoid the line cut, eliminate the potential accidents, by adopting pipeline three-dimensional attitude measuring instrument, to the trenchless pipeline in pipeline construction to carry on the accurate measurement and positioning, so as to solve the above other detection means can't solve the practical problems.

It should be noted that, in practical application, because the pipeline 3D attitude measuring instrument is based on the principle of accurately measuring its own motion trajectory and obtaining the central coordinate sequence of the measured pipeline, its measurement accuracy is not only limited by the built-in core inertial sensor measurement unit, but also closely related to the structural stability of the instrument during operation.Therefore, keeping the structure of the measuring pipe stable is also one of the prerequisites for accurate data measurement by the 3D attitude measuring instrument .