WO2017092181A1

WO2017092181A1 - Combined initial alignment system and alignment method for strapdown inertial navigation system of underground coal mining machine

Info

Publication number: WO2017092181A1
Application number: PCT/CN2016/074618
Authority: WO
Inventors: 李威; 杨海; 许少毅; 张金尧; 司卓印; 刘玉飞; 魏华贤; 鞠锦勇; 路恩; 董事; 盛连超; 杨康; 王茗; 须晓锋; 徐晗
Original assignee: 中国矿业大学
Priority date: 2015-12-02
Filing date: 2016-02-26
Publication date: 2017-06-08
Also published as: CN105371871A; CN105371871B; AU2016365012A1; AU2016365012B2

Abstract

A combined initial alignment system and alignment method for a strapdown inertial navigation system of an underground coal mining machine. The system comprises a strapdown inertial navigation system (4) installed on a coal mining machine (1), a wireless sensor network mobile node (5), an inclination sensor (3), a geomagnetic field sensor (2) and anchor nodes (8) installed on a hydraulic support (7). After the coarse alignment of the strapdown inertial navigation (4) is performed, the wireless sensor network is used to detect location information about the coal mining machine (1), the inclination sensor (3) measures a roll and a pitch angle, and the geomagnetic field sensor (2) measures a yaw angle. A pose measurement equation of the coal mining machine (1) is constructed, and is combined with an error model after the coarse alignment of the strapdown inertial navigation (4) is performed, so as to establish a state equation; fusion filtering is carried out to obtain accurate location and pose information about the coal mining machine (1); and the precise alignment of the strapdown inertial navigation system (4) is conducted to complete initial alignment. The precise initial alignment of a strapdown inertial navigation combination under a severe enclosed environment in a coal mine is realized, and the precision of combination positioning under a large misalignment angle of a strapdown inertial navigation system of a coal mining machine is greatly improved.

Description

Combined initial alignment system and alignment method for underground coal mining machine strapdown inertial navigation system

Technical field

The invention relates to a positioning and positioning initial alignment system and an alignment method for a downhole shearer, in particular to a combined initial alignment system and an alignment method for a downhole miner system of a downhole shearer.

Background technique

Coal is an important basic energy source and raw material in China. The coal-based energy structure will not change for a long time. With the development of the national economy, the demand for coal is increasing, and the accompanying coal mine safety accidents are also constantly increase. The safe and efficient development and utilization of coal resources has become a hot research topic for scholars at home and abroad. One of the most effective solutions is to realize the mechanization and automation of coal mine production equipment, so that the underground comprehensive mining face can be mined by no one or less. The information-aware technology of the three-machine mining machine is the key technology to realize the automation of mining three machines.

In order to realize the position and attitude detection of the shearer, some scholars have proposed the inertial navigation and positioning method of the shearer. The strapdown inertial navigation system refers to the gyroscope and accelerometer directly fixed on the carrier. The inertial sensor such as gyroscope and accelerometer is used to measure the triaxial angular velocity and triaxial acceleration information of the running carrier in real time, combined with the initial inertia of the running carrier. Information, through high-speed integration to obtain navigation information such as the attitude, speed and position of the motion carrier. The strapdown inertial navigation system does not rely on external information, does not radiate energy to the outside world, and is not susceptible to interference and damage. It is an autonomous navigation system with the advantages of high data update rate, comprehensive data and high short-term positioning accuracy.

However, since the Strapdown Inertial Navigation System is an incremental solution process, the position and attitude update of the Strapdown Inertial Navigation is performed by integrating the acceleration and angular velocity to obtain the position increment and attitude angle increment of the motion carrier. Therefore, the initial value of the positioning parameter of the strapdown inertial navigation at the initial position of the positioning can be accurately measured, and the accuracy of the positioning operation process can be determined. Moreover, the strapdown inertial navigation has a serious drop in positioning accuracy due to the accumulated error under long-term operation, so it is necessary to seek an external positioning method to correct its position result.

As a positioning system with distributed, intelligent and networked functions, wireless sensor networks have great potential in the field of short-distance positioning. At present, in the coal mine roadway, the personnel positioning technology based on the wireless sensor network is an important part of the coal mine safety mining technology. Therefore, the three-dimensional position of the shearer is measured by the wireless sensor network to provide initial alignment for the strapdown inertial navigation. location information. Since the wireless sensor network cannot provide the attitude information of the motion carrier, and the initial attitude matrix of the strapdown inertial navigation directly affects the velocity and position solution under acceleration, the external inclination sensor and the earth magnetic field sensor must be used to respectively perform the shearer strapdown inertial navigation. The roll angle, pitch angle and yaw angle are measured to obtain the initial attitude information of the shearer. A combined positioning system is established, and the initial positioning parameters of the strapdown inertial navigation are solved by the initial alignment algorithm of the moving base, and the initial alignment of the combination of the strapdown inertial navigation is realized.

Summary of the invention

The object of the present invention is to provide a combined initial alignment system and alignment method for a downsaw miner system of a downhole shearer, which solves the problem that the initial alignment of the shearer strapdown inertial navigation system cannot rely on traditional GPS positioning. The problem of precise initial alignment of the moving base.

The object of the present invention is achieved in that the combined initial alignment system comprises: a shearer 1, a geomagnetic sensor 2, a tilt sensor 3, a strapdown inertial navigation system 4, a wireless sensor network mobile node 5, a scraper conveyor 6, a hydraulic pressure The bracket 7 and the wireless sensor network anchor node 8; the geomagnetic sensor 2, the tilt sensor 3, the strapdown inertial navigation system 4, and the wireless sensor network mobile node 5 are connected to the shearer 1, and the shearer 1 rides on the scraper conveyor 6 Performing a reciprocating coal cutting motion; a wireless sensor network anchor is connected to the hydraulic support 7 Node 8; the wireless sensor network anchor node is connected by a shielded network cable, and wireless data is transmitted to the positioning host through the switch; the strapdown inertial navigation system, the tilt sensor, and the geomagnetic field sensor are transmitted through a wireless data The module transmits the positioning data to the remote positioning host.

Combining the initial alignment method, the position information of the shearer is measured by the wireless sensor network after the rough alignment of the strapdown inertial navigation, the inclination sensor measures the roll and pitch angle, the geomagnetic field sensor measures the yaw angle, and the time synchronization method is used to construct the mining method. The attitude measurement equation of the coal machine is combined with the error model of the strap-down inertial alignment to establish the equation of state, and the fusion filtering is performed to obtain the accurate position information of the shearer and the fine alignment of the strapdown inertial navigation. , complete the initial alignment; the specific steps are as follows:

1) The three-axis accelerometer and the three-axis gyroscope in the Strapdown Inertial Navigation System measure the three-axis acceleration and the three-axis angular velocity information of the shearer when the shearer is stationary, and after collecting the data for a period of time The processing is used to establish the initial attitude transformation matrix of the strapdown inertial navigation system when the shearer is stationary, and the rough alignment of the strapdown inertial navigation is obtained by using the measured data. The error transfer model under the coarse alignment of the inertial navigation;

2) The wireless sensor network anchor node receives the wireless signal transmitted from the mobile node in real time, and measures the wireless signal of the mobile node from multiple anchor nodes, and obtains the location of the shearer under the wireless sensor network measurement through the wireless sensor network location solution model. information;

3) The inclination sensor is fixedly mounted on the fuselage of the shearer, and the inclination information of the shearer body relative to the horizontal plane is measured in real time, and the inclination information is taken according to the installation position parameter of the inclination sensor on the shearer body. The conversion of the pitch angle and the roll angle of the coal machine; the geomagnetic field sensor fixedly mounted on the body of the shearer measures the earth's magnetic field information of the position of the shearer fuselage in real time, and measures the direction of the earth's magnetic field and according to the earth's magnetic pole The theory calculates the yaw angle of the shearer, obtains the three-dimensional attitude information of the pitch angle, roll angle and yaw angle of the shearer fuselage, and determines the initial attitude of the strapdown inertial navigation system;

4) Using the error transfer model of the strapdown inertial navigation system to establish a state equation based on position and attitude error, and establish coal mining based on the initial position determined by the wireless sensor network and the initial attitude determined by the combination of the tilt sensor and the geomagnetic sensor. The position and attitude combination observation equation of the machine body; the state space model of the shearer combined positioning system is constructed by using the state equation of the positioning system and the combined observation equation;

5) According to the state equation of the combined positioning system and the characteristics of the combined observation equation, it is considered that the observation equation is composed of three different sensors, and then the multi-dimensional federated Kalman filter model based on multi-sensor is constructed; through the combined filtering of the state space model The accurate initial position and initial attitude information of the shearer under the combined positioning system are obtained, and the accurate Strapdown Inertial Position and Attitude Error Equations are established, and the Strapdown Inertial Navigation System is precisely aligned to achieve accurate initial integration of the Strapdown Inertial Navigation System. The position information calibration provides an initial guarantee for the subsequent real-time positioning process, which improves the positioning accuracy of the shearer;

The time synchronization method, in view of the combination positioning system is composed of independent sensor systems that are not related to each other, each sensor separately transmits data to the positioning host, so each sensor positioning host transmits different data acquisition time, and needs multiple sensors Under the multi-source data synchronization and acquisition time registration, when the observation equation under multi-sensor measurement is established, the observation measurement can reflect the measurement state at the current time and reduce the observation error caused by the time asynchronous; the specific steps are as follows:

1) In the rough alignment process, the Strapdown inertial navigation acquires the acceleration and angular velocity information of the shearer at rest time, and sends the data sampling clock signal T _{0 of the} strapdown inertial navigation to the wireless sensor network and the dip in the data acquisition. The data acquisition module of the sensor and the geomagnetic field sensor, each data acquisition module receives a relative clock count of the wireless sensor network data, the dip angle data and the geomagnetic field data collected by the SINS through the sampling clock of the SINS, and respectively obtains the receiving wireless sensor. Network positioning data, tilt sensor data, and synchronous acquisition times T ₁ , T _{2 ,} and T ₃ under geomagnetic data;

2) wireless sensor network positioning data collection module after the time synchronization obtained by sampling position data at time T _1, and if the positioning data is valid after the judgment, if invalid then continue to collect returns, effectively the transmission T of angle acquisition module and the geomagnetic field acquisition module ₁ time synchronously measures the trigger signal, and performs receiving and latching of the wireless measurement value;

3) After receiving the T ₁ synchronization signal sent by the wireless sensor network acquisition module, the inclination data acquisition module compares and judges with the self-tilt sensor data sampling time T _{2 ,} and considers that when the time difference between the two times is less than an allowable time threshold ε ₂ tilt measurement time data received wireless data and synchronization time T _1, and receives the measured value of the tilt latch, otherwise tilt sensor selected re-sampling the sampled data;

4) After receiving the T ₁ synchronization signal sent by the wireless sensor network acquisition module, the geomagnetic data acquisition module compares with the local geomagnetic sensor data sampling time T ₃ , when the time difference between the two times is less than an allowable time threshold ε, T ₃ that received time geomagnetic measured data synchronization with the wireless data at time T ₁ and the latch receiving measurement value amount field, a geomagnetic sensor or for re-sampling the sampled data selected;

5) Based on the time-synchronized wireless sensor network positioning data, the tilt sensor data and the geomagnetic field sensor data combined with the sampling data of the Strapdown Inertial Navigation System, the integrated alignment system is established, and finally the combined positioning system under time synchronization is realized. alignment.

The beneficial effect is that, due to the above scheme, an external sensor such as a wireless sensor network, a tilt sensor and a geomagnetic sensor is used to realize an initial alignment difficulty of a coal mining machine strapdown inertial navigation positioning system in a coal mine underground environment. The initial alignment system of the strapdown inertial navigation base under the combined positioning system realizes accurate initial alignment of the GPS-independent strapdown inertial navigation combination in the coal mine, which can greatly improve the large misalignment angle of the shearer strapdown inertial navigation system. The combined positioning accuracy provides accurate position and attitude information for the shearer positioning process. The invention solves the problem that the initial alignment of the shearer strap-down inertial navigation positioning system can not rely on the traditional GPS positioning, and the precise initial alignment of the moving base achieves the object of the invention.

The advantages of the invention are:

(1) The present invention proposes a combined initial alignment system applied to a coal mine underground coal mining machine strapdown inertial navigation system. After the rough alignment of the strapdown inertial navigation, the utility model is installed on the shearer body. The wireless sensor network mobile node, the tilt sensor and the geomagnetic field sensor construct a combined positioning system to precisely align the Strapdown inertial navigation, which can solve the problem that it is difficult to rely on the external positioning system to initially align the strapdown inertial navigation in the closed environment of the coal mine;

(2) The present invention proposes a state observation space equation using a wireless sensor network positioning data, a tilt sensor and a geomagnetic field sensor to establish a combined observation equation, and a state space model for establishing a state equation by using an error model of the strapdown inertial alignment. At the same time, a multi-dimensional federated Kalman filter is proposed to fuse it, which improves the accuracy of the positioning system.

(3) The present invention is directed to a time-synchronous problem generated by independent data observation under multi-sensors. A multi-sensor time synchronization scheme based on strapdown inertial navigation sampling frequency is proposed, which uses the wireless sensor network to locate data moments and The inclination sensor and the geomagnetic field sensor select the synchronous data to realize the time synchronization of the multi-sensor measurement data, which improves the accuracy of the combined positioning system.

BRIEF DESCRIPTION OF THE DRAWINGS:

1 is a schematic view showing the structure of a combined initial alignment system of a down-saw miner system of a downhole shearer according to the present invention;

2 is a block diagram showing a program operation structure of a combined initial alignment method of a down-saw inertial navigation system for a downhole shearer according to the present invention;

3 is a flow chart showing the execution of a time synchronization scheme of the combined positioning system in the proposed combined initial alignment system of the present invention.

In the picture, 1-Shearer, 2-Geomagnetic sensor, 3-tilt sensor, 4-Striped inertial navigation system, 5-wireless sensor network mobile node, 6-scraper conveyor, 7-hydraulic bracket, 8-wire Sensor network anchor node, T0- is the sampling time of strapdown inertial navigation data, T1- is wireless The sensor network locates the data sampling time, T2- is the inclination sensor data sampling time, T3- is the geomagnetic sensor data sampling time, and ε- is the two sensor data sampling time interval threshold allowed in the synchronization method.

detailed description

The invention provides a combined initial alignment system and an alignment method for a downhole miner system of a downhole shearer, and the combined initial alignment system comprises: a shearer 1, a geomagnetic sensor 2, a tilt sensor 3, and a strapdown inertial navigation System 4, wireless sensor network mobile node 5, scraper conveyor 6, hydraulic support 7 and wireless sensor network anchor node 8; geomagnetic sensor 2, tilt sensor 3, strapdown inertial navigation system 4 and wireless sensor network mobile node 5 are connected On the shearer 1, the shearer 1 rides on the scraper conveyor 6 to perform a reciprocating coal cutting movement; the hydraulic support 7 is connected with a wireless sensor network anchor node 8; the wireless sensor network anchor node is connected by a shielded network cable And transmitting wireless data to the positioning host through the switch; the strapdown inertial navigation system, the tilt sensor, and the ground magnetic field sensor transmit the positioning data to the remote positioning host through a wireless data sending module.

5) According to the state equation of the combined positioning system and the characteristics of the combined observation equation, it is considered that the observation equation is composed of three different sensors, and then the multi-dimensional federated Kalman filter model based on multi-sensor is constructed; through the combined filtering of the state space model The accurate initial position and initial attitude information of the shearer under the combined positioning system are obtained, and the accurate Strapdown Inertial Position and Attitude Error Equations are established, and the Strapdown Inertial Navigation System is precisely aligned to achieve accurate initial integration of the Strapdown Inertial Navigation System. The calibration of the pose information provides an initial guarantee for the subsequent real-time positioning process, which improves the positioning accuracy of the shearer.

The time synchronization method, in view of the combination positioning system is composed of independent sensor systems that are not related to each other, each sensor separately transmits data to the positioning host, so each sensor positioning host transmits different data acquisition time, and needs multiple sensors Under Multi-source data synchronization and acquisition time registration, so that when establishing the observation equation under multi-sensor measurement, the observation measurement can reflect the current measurement state and reduce the observation error caused by time asynchronous; the specific steps are as follows:

The invention will be further described in detail below with reference to the accompanying drawings.

Embodiment 1: As shown in FIG. 1 , the present invention provides a combined initial alignment system for a down-saw miner's strap-down inertial navigation system, which is mainly installed by a strap mounted on the fuselage of the shearer (1). The inertial navigation system (4), the wireless sensor network mobile node (5), the tilt sensor (3), the geomagnetic field sensor (2), and the wireless sensor network anchor node (8) mounted on the hydraulic support (7), and The coal machine rides on the scraper conveyor (6) to perform a reciprocating coal cutting movement; the wireless sensor network anchor node (8) is connected by a shielded network cable, and the anchor node is powered by the switch and transmits the wireless positioning data to the positioning. In the host, the strapdown inertial navigation system (4), the tilt sensor (3), and the geomagnetic field sensor (2) transmit the positioning data to the remote positioning host through a wireless data transmitting module. The positioning host receives the positioning data from the wireless sensor network in real time, and receives the data measured in real time from the strapdown inertial navigation system, the tilt sensor and the ground magnetic field sensor through the wireless data transmission module.

The Strapdown Inertial Navigation System measures the acceleration and angular velocity information of the shearer body in real time through its three-axis accelerometer and three-axis gyroscope, and transmits it to the positioning host through the wireless data transmission system for position and attitude calculation; wireless sensor The network receives the wireless positioning signal transmitted by the mobile node in real time through the anchor node installed on the hydraulic support, and obtains the three-dimensional position information of the shearer body through the wireless positioning solution model; the geomagnetic field sensor is based on the measuring shearer The geomagnetic field signal at the location of the fuselage, and the yaw angle of the shearer fuselage is calculated according to the earth magnetic field model.

As shown in FIG. 2, a combined initial alignment method of a downhole shearer strapdown inertial navigation system includes the following steps:

Step 1, the three-axis accelerometer and the three-axis gyroscope in the strapdown inertial navigation system (4) measure the shearer when the shearer (1) is stationary The triaxial acceleration and triaxial angular velocity information are processed by the positioning host after 30 s, and the acceleration acceleration and angular velocity data are processed by the positioning host, and the characteristics such as the fixed direction of gravity acceleration, the fixed size, and the angular velocity of the earth are used for the strapdown inertial property. The influence characteristics of the navigation measurement results are established. The initial attitude transformation matrix of the strapdown inertial navigation when the shearer is stationary is:

among them,

γ ₀ and θ ₀ respectively yaw angle, roll angle and pitch angle after the rough alignment of the inertial navigation.

And using the measured data to carry out the rough alignment of the strapdown inertial navigation, and then obtain the error transfer model under the rough alignment of the strapdown inertial navigation;

Where Φ ^t is the error angle matrix.

Step 2: The wireless sensor network anchor node (8) receives the wireless signal transmitted from the mobile node (5) in real time, and measures the wireless signal of the mobile node from multiple anchor nodes, and the TDOA/AOA position solving model can be adopted through the wireless sensor network. The three-dimensional position information of the shearer measured by the wireless sensor network is obtained, and the position vector can be expressed as:

P _wsn =[x _wsn y _wsn z _wsn ]

Step 3, the inclination sensor (3) is fixedly mounted on the fuselage of the shearer, and the inclination information of the shearer body relative to the horizontal plane is measured in real time, and according to the installation position parameter of the inclination sensor on the shearer body The inclination information is converted to the shearer pitch angle and the roll angle, wherein the inclination conversion matrix is:

Where γ _d and θ _d are the measured values of the tilt sensor, respectively.

The geomagnetic field sensor (2) fixedly mounted on the shearer fuselage measures the earth's magnetic field information of the position of the shearer fuselage in real time, and measures the direction of the earth's magnetic field and can be used to measure the shearer's bias according to the earth's magnetic pole theory. The yaw angle calculation matrix, the yaw angle conversion matrix is:

among them,

The shearer yaw angle is calculated for the geomagnetic sensor.

Furthermore, the three-dimensional attitude observation information of the pitch angle, the roll angle and the yaw angle of the shearer body is obtained, and the initial attitude determination of the strapdown inertial navigation system is realized;

In step 4, the state equation based on position and attitude error is established by using the error transfer model after the rough alignment of the strapdown inertial navigation system. In the northeast sky coordinate system, the state equation of the dynamic error model is

Where t is the system runtime,

For the state vector of the error equation of the Strapdown Inertial Navigation System, δP ^T is the position error, and δV ^nT is the velocity error.

For attitude error, ε ^T and

They are the gyro zero-bias and accelerometer zero-bias, F(t) is the strap-down inertial system state transition matrix, and the w(t) state equation noise vector.

According to the initial position determined by the wireless sensor network and the initial attitude determined by the tilt sensor and the geomagnetic field sensor, the position and attitude combination observation equation of the shearer fuselage is established, as shown in the following formula:

z(t)=H(t)x(t)+v(t)

In the formula,

H(t) is the transfer matrix of the observation equation, and v(t) is the observed noise vector.

The state space model of the shearer combined positioning system is constructed by using the state equation of the positioning system and the combined observation equation;

Step 5, according to the state equation of the combined positioning system and the characteristics of the combined observation equation, considering that the observation equation is composed of three different sensors, and then constructing a multi-dimensional federated Kalman filter model based on multi-sensor, and the Kalman filter model is as follows Shown.

initialization:

prediction:

Fix:

P _k|k =(IK _k H _k )P _k|k-1

Through the combined filtering of the state space model, the accurate initial position and initial attitude information of the shearer under the combined positioning system are obtained, and the accurate strapdown inertial position and attitude error equations are established, and the Strapdown inertial navigation system is precisely aligned. In turn, the accurate initial pose information calibration of the strapdown inertial navigation is realized, which provides an initial guarantee for the subsequent real-time positioning process and improves the positioning accuracy of the shearer;

As shown in FIG. 3, according to the time synchronization method of the combined initial alignment method of the downhole miner system of the downhole shearer, it is considered that the combined positioning system is composed of four independently operated sensors, and there is no electrical connection between the sensors. And the data is independently transmitted to the positioning host, so it is necessary to consider the asynchronous problem of data transmission time between the multiple sensors, and establish a synchronization strategy for time asynchronous, and improve the measurement accuracy of the combined positioning system.

In the rough alignment process, the Strapdown inertial navigation acquires the acceleration and angular velocity information of the shearer at rest time, and sends the data sampling clock signal T _{0 of the} strapdown inertial navigation to the wireless sensor network, the tilt sensor and the data acquisition. The data acquisition module of the geomagnetic field sensor, each data acquisition module receives a relative clock count of the wireless sensor network data, the dip angle data and the geomagnetic field data collected by the SINS through the sampling clock of the SINS, and respectively obtains the positioning of the wireless sensor network in the receiving wireless sensor. Data, tilt sensor data, and simultaneous acquisition times T ₁ , T _{2 ,} and T ₃ under geomagnetic data;

Wireless sensor network localization data acquisition module after the time synchronization obtained by sampling position data at time T ₁ is P _wsn (T _1), if the positioning data is valid after the judgment, if invalid then continue to collect returns, it is valid for tilt angle acquisition module and geomagnetic acquisition means for transmitting the synchronization time T ₁ measurement trigger signal, and latches the received radio measurement value;

After receiving the T ₁ synchronization signal sent by the wireless sensor network acquisition module, the inclination data acquisition module compares with the self-tilt sensor data sampling time T ₂ , and when the time difference between the two times is less than an allowable time threshold ε, that is, T ₂ - T ₁ < ε, it is considered that the inclination measurement data received at time T _{2 is} synchronized with the wireless data at time T ₁ , and the inclination measurement value is performed.

Receive latch, otherwise resample the tilt sensor sample data;

After receiving the T ₁ synchronization signal sent by the wireless sensor network acquisition module, the geomagnetic data acquisition module compares with the local geomagnetic sensor data sampling time T ₃ , and when the time difference between the two times is less than an allowable time threshold ε, that is, T ₃ -T ₁ <ε, it is considered that the geomagnetic field measurement data received at time T _{3 is} synchronized with the wireless data at time T ₁ and the geomagnetic field measurement value is performed.

Receiving latch, otherwise re-sampling the sampling data of the geomagnetic field sensor;

According to the time-synchronized wireless sensor network positioning data, the tilt sensor data and the geomagnetic field sensor data combined with the sampling data of the Strapdown Inertial Navigation System, the integrated navigation system fine alignment model is established, and finally the initial alignment of the combined positioning system under time synchronization is realized. .

Claims

A combined initial alignment system for a downhole miner's strapdown inertial navigation system, characterized in that: the combined initial alignment system comprises: a shearer 1, a geomagnetic sensor 2, a tilt sensor 3, a strapdown inertial navigation system 4, and a wireless The sensor network mobile node 5, the scraper conveyor 6, the hydraulic support 7 and the wireless sensor network anchor node 8; the geomagnetic sensor 2, the tilt sensor 3, the strapdown inertial navigation system 4 and the wireless sensor network mobile node 5 are connected to the shearer 1 The shearer 1 rides on the scraper conveyor 6 to perform a reciprocating coal cutting movement; the hydraulic support 7 is connected with a wireless sensor network anchor node 8; the wireless sensor network anchor node is connected by a shielded network cable and passes through the switch The wireless data is transmitted to the positioning host; the strapdown inertial navigation system, the tilt sensor, and the geomagnetic field sensor transmit the positioning data to the remote positioning host through a wireless data transmitting module.
The method for aligning a combined initial alignment system of a downhole miner's strapdown inertial navigation system according to claim 1, wherein: the initial alignment method is combined to utilize a wireless sensor network after rough alignment of the strapdown inertial navigation Measuring the position information of the shearer, the inclination sensor measures the roll and pitch angle, the geomagnetic field sensor measures the yaw angle, and constructs the position and orientation measurement equation of the shearer according to the time synchronization method, and combines the rough alignment of the strap joint inertial guide The error model establishes the state equation, performs fusion filtering, obtains accurate shearer pose information, and performs fine alignment of the strapdown inertial navigation to complete the initial alignment; the specific steps are as follows:

1) The three-axis accelerometer and the three-axis gyroscope in the Strapdown Inertial Navigation System measure the three-axis acceleration and the three-axis angular velocity information of the shearer when the shearer is stationary, and after collecting the data for a period of time The processing is used to establish the initial attitude transformation matrix of the strapdown inertial navigation system when the shearer is stationary, and the rough alignment of the strapdown inertial navigation is obtained by using the measured data. The error transfer model under the coarse alignment of the inertial navigation;

2) The wireless sensor network anchor node receives the wireless signal transmitted from the mobile node in real time, and measures the wireless signal of the mobile node from multiple anchor nodes, and obtains the location of the shearer under the wireless sensor network measurement through the wireless sensor network location solution model. information;

3) The inclination sensor is fixedly mounted on the fuselage of the shearer, and the inclination information of the shearer body relative to the horizontal plane is measured in real time, and the inclination information is taken according to the installation position parameter of the inclination sensor on the shearer body. The conversion of the pitch angle and the roll angle of the coal machine; the geomagnetic field sensor fixedly mounted on the body of the shearer measures the earth's magnetic field information of the position of the shearer fuselage in real time, and measures the direction of the earth's magnetic field and according to the earth's magnetic pole The theory calculates the yaw angle of the shearer, obtains the three-dimensional attitude information of the pitch angle, roll angle and yaw angle of the shearer fuselage, and determines the initial attitude of the strapdown inertial navigation system;

4) Using the error transfer model of the strapdown inertial navigation system to establish a state equation based on position and attitude error, and establish coal mining based on the initial position determined by the wireless sensor network and the initial attitude determined by the combination of the tilt sensor and the geomagnetic sensor. The position and attitude combination observation equation of the machine body; the state space model of the shearer combined positioning system is constructed by using the state equation of the positioning system and the combined observation equation;

5) According to the state equation of the combined positioning system and the characteristics of the combined observation equation, it is considered that the observation equation is composed of three different sensors, and then the multi-dimensional federated Kalman filter model based on multi-sensor is constructed; through the combined filtering of the state space model The accurate initial position and initial attitude information of the shearer under the combined positioning system are obtained, and the accurate Strapdown Inertial Position and Attitude Error Equations are established, and the Strapdown Inertial Navigation System is precisely aligned to achieve accurate initial integration of the Strapdown Inertial Navigation System. The calibration of the pose information provides an initial guarantee for the subsequent real-time positioning process, which improves the positioning accuracy of the shearer.
The combined initial alignment method of the downhole shearer strapdown inertial navigation system according to claim 1, wherein: said time synchronization method, wherein the combined positioning system is composed of independent sensor systems that are not related to each other. Each sensor separately transmits data to the positioning host. Therefore, the data acquisition time transmitted by each sensor positioning host is different, and multi-source data synchronization and acquisition time registration under multiple sensors are required, so that observation under multi-sensor measurement is established. When the equation is used, the observation can reflect the current The measurement state of the moment reduces the observation error caused by the asynchronous time; the specific steps are as follows:

1) In the rough alignment process, the Strapdown inertial navigation acquires the acceleration and angular velocity information of the shearer at rest time, and sends the data sampling clock signal T 0 of the strapdown inertial navigation to the wireless sensor network and the dip in the data acquisition. The data acquisition module of the sensor and the geomagnetic field sensor, each data acquisition module receives a relative clock count of the wireless sensor network data, the dip angle data and the geomagnetic field data collected by the SINS through the sampling clock of the SINS, and respectively obtains the receiving wireless sensor. Network positioning data, tilt sensor data, and synchronous acquisition times T 1 , T 2 , and T 3 under geomagnetic data;

2) wireless sensor network positioning data collection module after the time synchronization obtained by sampling position data at time T 1, and if the positioning data is valid after the judgment, if invalid then continue to collect returns, effectively the transmission T of angle acquisition module and the geomagnetic field acquisition module 1 time synchronously measures the trigger signal, and performs receiving and latching of the wireless measurement value;

3) After receiving the T 1 synchronization signal sent by the wireless sensor network acquisition module, the inclination data acquisition module compares and judges with the self-tilt sensor data sampling time T 2 , and considers that when the time difference between the two times is less than an allowable time threshold ε 2 tilt measurement time data received wireless data and synchronization time T 1, and receives the measured value of the tilt latch, otherwise tilt sensor selected re-sampling the sampled data;

4) After receiving the T 1 synchronization signal sent by the wireless sensor network acquisition module, the geomagnetic data acquisition module compares with the local geomagnetic sensor data sampling time T 3 , when the time difference between the two times is less than an allowable time threshold ε, T 3 that received time geomagnetic measured data synchronization with the wireless data at time T 1 and the latch receiving measurement value amount field, a geomagnetic sensor or for re-sampling the sampled data selected;

5) Based on the time-synchronized wireless sensor network positioning data, the tilt sensor data and the geomagnetic field sensor data combined with the sampling data of the Strapdown Inertial Navigation System, the integrated alignment system is established, and finally the combined positioning system under time synchronization is realized. alignment.