Monorail hoist positioning method combining rail joint beacons and inertial navigation

Abstract

A monorail hoist positioning method combining rail joint beacons and inertial navigation. An odometry kinematic model for a monorail hoist is established by means of an encoder on the monorail hoist, and an extended Kalman filter is used to fuse a heading angle obtained from a kinematic model solution and a heading angle obtained from a strapdown inertial navigation solution. Beacons are arranged at rail joints for the monorail hoist, and vibration signals are acquired by a vibration sensor. By combining a strapdown inertial navigation system, the encoder, and a rail installation diagram, a rail joint determination model is constructed to perform filtering, so as to obtain impact signals at rail joint beacons that meet a requirement. Beacon identifiers are used to match the identified rail joint beacons against specific beacon coordinates in the rail installation diagram, so as to obtain a time-position coordinate sequence for the monorail hoist arriving at the rail joints. A combined positioning model integrating rail joint beacons and strapdown inertial navigation is constructed to realize integration of local relative positioning and global absolute positioning of the monorail hoist. The method can improve the positioning accuracy of the monorail hoist while reducing positioning costs.

Description

Rail joint beacon and inertial navigation combined monorail positioning method TECHNICAL FIELD

[0001] The present application relates to the technical field of underground monorail positioning, in particular to a rail joint beacon and inertial navigation combined monorail positioning method. BACKGROUND

[0002] In the actual production process of coal, auxiliary transportation is one of the most important links. The monorail is currently one of the main auxiliary transportation equipment in the coal mine. Its main function is to transport personnel and materials, and has large traction and runs along the steel rails fixed on the top of the coal mine roadway. The running speed is not affected by the road conditions of the ground, so it is widely used in underground. In order to realize intelligent scheduling of the underground auxiliary transportation system, accurate positioning of the monorail is an important part of realizing intelligent scheduling of the underground auxiliary transportation system.

[0003] Limited to the special environment of the coal mine, GPS and Beidou navigation positioning systems cannot be used underground. The positioning technologies currently applied in coal mines mainly include wireless positioning technology and inertial navigation technology. Wireless positioning technology includes laser scanning positioning technology, Bluetooth positioning technology, Wi-Fi positioning technology, RFID positioning technology, ZigBee positioning technology, and UWB positioning technology. However, there are problems such as signal attenuation caused by wireless signal reflection, non-line-of-sight scenarios, and multipath effects, which limit the application of various wireless positioning technologies in coal mines. Inertial navigation technology calculates position information through measured acceleration and angular velocity information. Although it has strong autonomy and is not affected by external environment, due to the existence of cumulative error, it cannot be used for long-time high-precision positioning.

[0004] The research on monorail positioning technology in coal mines is still insufficient, and there are problems such as poor autonomy, high cost, difficulty in orientation, and insufficient reliability. An effective solution is to find a new, reliable, and low-cost positioning technology suitable for monorail in coal mines, and to combine positioning technologies with different characteristics to improve the accuracy and stability of the entire positioning system. SUMMARY

[0005] In view of the above technical deficiencies, the purpose of the present application is to provide a rail joint beacon and inertial navigation combined monorail positioning method, which combines natural beacon identification, kinematics modeling, dead reckoning algorithm, strapdown inertial navigation algorithm, rail joint judgment model and adaptive extended Kalman filtering algorithm, realizes low-cost, high-precision and reliable positioning of monorail in coal mine, and provides technical support for realizing intelligent scheduling of underground auxiliary transportation system.

[0006] To solve the above technical problems, the technical scheme adopted by the present application is as follows:

[0007] The application provides a monorail crane positioning method based on a track joint beacon and an inertial navigation system, and comprises the following steps:

[0008] S1: an encoder is installed on a driving wheel of the monorail crane, forward speed, heading angle and heading angle velocity information of the monorail crane are obtained from a data obtained by the encoder and a mileage kinematic model of the monorail crane, and the forward speed, the heading angle and the heading angle velocity information of the monorail crane are obtained from the mileage kinematic model;

[0009] S2: data obtained by a strapdown inertial navigation system installed on the monorail crane are used for strapdown inertial navigation calculation, and attitude, speed and position information of the monorail crane are obtained;

[0010] S3: an extended Kalman filtering algorithm is used to fuse the heading data obtained based on the mileage kinematic model and the heading angle obtained by the strapdown inertial navigation calculation, and a combined positioning result of the inertial navigation and the mileage is obtained;

[0011] S4: a beacon is arranged at a track joint of the monorail crane, numbers of the beacons and specific position information at the beacons are determined according to a track installation diagram of the monorail crane, and a transportation route of the monorail crane is divided into a plurality of driving sections by using the position information determined by the beacons;

[0012] S5: a vibration sensor is installed at the driving wheel of the monorail crane, vibration signals in a driving process of the monorail crane are collected by using the vibration sensor, and the collected vibration signals are processed to identify vibration impact signals in the driving process;

[0013] S6: based on information collected by the strapdown inertial navigation system and the encoder, a track joint judgment model is constructed in combination with the track installation diagram, a suitable threshold value is set according to a length of the track, the extracted pulse signals are judged, impact signals meeting the requirements, i.e. impact signals at the track joint beacons, are screened out, and the identified impact signals at the track joint beacons are numbered;

[0014] S7: the numbers of the identified track joint beacons are used to match the numbers and the specific positions of the beacons in the track installation diagram, and time when the monorail crane runs to the track joint and a coordinate sequence of the position are obtained;

[0015] S8: a combined positioning model of the track joint beacon and the strapdown inertial navigation system is established, absolute positioning information obtained by combining the track joint beacon identification judgment and the track installation diagram is used to realize stage calibration and reset of the positioning information of the monorail crane, and the combination of the local relative positioning and the global absolute positioning of the monorail crane is realized.

[0016] Preferably, in step S3, the extended Kalman filtering algorithm is used to obtain a primary positioning result FPR of the monorail crane t =(t,x0,y0,z0), wherein t is time of the positioning result, x, y and z are coordinates of the monorail crane.

[0017] Preferably, in step S4, the track joint beacons are sequentially numbered N1, N2, N3, ..., N according to the track installation diagram and the number of monorail track joints in the entire operating route. m Where m is the total number of track joint beacons; combined with the position coordinates (x, y) of the i-th track joint in the track installation diagram. i ,y i ,z i ), mark each bea as Bea i =(N i ,x i ,y i ,z i ), defined as number N i The guide rail length between the current track joint beacon and the previous track joint beacon is L. i .

[0018] Preferably, in step S5, the acquired signal is preprocessed and filtered to remove noise interference; and peak detection is performed on the signal. The process from departure to stopping of the monorail is set as an interval. Within an interval, the average value P of the preprocessed signal peak is set as the threshold. If the peak value V of signal x(t) is... P If (t) exceeds the set threshold P, then the signal is recorded as the impact signal X(t).

[0019] Preferably, in step S6, the specific method for setting the threshold of the model is as follows:

[0020] The monorail's running route is obtained based on the attitude, speed, and position information calculated by the strapdown inertial navigation system. The mileage of the monorail is collected using an encoder and denoted as S(t). The impact signal X(t) extracted in step S5 is matched with the mileage S(t) using a timestamp, and this match is denoted as the impact signal I. k =(X(t),S k (t)), where k is the sequence number of the impact signal according to time;

[0021] Bea beacons for each track joint along the running route are obtained from the track installation diagram. i And the length of each track is L i The beacons at each junction along the route are numbered according to the operational sequence as n1, n2, n3, ..., n j ..., let R be the beacon for each track joint in the running route. j _Bea i =(n j N i ,x i ,y i ,z i); the running distance between the monorail crane vehicle position and the joint beacon n1 is Y1, and the joint beacon n k is the track length between the joint beacon n k+1 ; k+1 ;

[0022] The running route of the monorail crane is divided into subintervals with lengths Y1, Y2,..., Y j by the joint beacons, and the threshold value of each interval in the judgment model is set as BD k =(0.9-1.1)·Y k .

[0023] Preferably, in step S6, the specific steps of judging and screening the impact signals in the judgment model are as follows:

[0024] First, the set threshold value of the monorail crane in the first subinterval is BD1=(0.9-1.1)·Y1, and whether the running distance R_S1(t)=S1(t)-0 of the impact signal I1 in the first subinterval satisfies the set threshold condition is judged, if 0.9·Y1≤R_S1(t)≤1.1·Y1 is satisfied, the impact signal I1 is the impact signal at the first track joint in the running route, numbered as n1';

[0025] If the threshold condition is not satisfied, I2, I3,..., I k are verified in the same way until the condition is satisfied, and the impact signal I p satisfying the condition is recorded as I1'=(I p ,n1',t);

[0026] Given I r '=(I q ,n r ',t), the set threshold value of the r+1th subinterval is BD r+1 =(0.9-1.1)·Y r+1 , and whether the running distance R_S q+1 (t)=S q+1 (t)-S q+1 (t) of the impact signal I q in the r+1th subinterval satisfies the threshold condition is judged, if 0.9·Y r+1 ≤R_S q+1 (t)≤1.1·Y r+1 is satisfied, the impact signal I q+1 is the impact signal at the r+1th track joint in the running route, numbered as n r+1 ';

[0027] If the threshold condition is not satisfied, I q+2 ,Iq+3 ..., I k , until the condition is met, and the impact signal I q that meets the condition is recorded as I r+1 ' = (I q+1 , n r+1 ', t).

[0028] Preferably, in step S7, the track joint beacon R j _Bea i = (n j , N i , x i , y i , z i ) in the running route is matched with the impact signal I r+1 ' = (I q+1 , n r+1 ', t) obtained by screening the track joint through the matching model, if r+1 = j, then I r+1 ' is matched with R j _Bea i , and the time-coordinate sequence F ti _Bea i = (t, x i , y i , z i ) of the monorail running to the track joint is obtained.

[0029] Preferably, in step S8, the primary positioning result FPR t = (t, x0, y0, z0) of the monorail and the time-coordinate sequence F ti _Bea i = (t, x i , y i , z i ) of the monorail running to the track joint are matched, if ti = t, then the positioning information in F ti _Bea i is used to correct the position information of FPR t , so as to realize the phased calibration and resetting of the positioning information of the monorail.

[0030] The present application has the following advantages:

[0031] The present application uses the track joint as a natural beacon for positioning, and compared with other beacon types and the currently used tag method, the natural beacon has low cost and does not need artificial installation to reduce errors.

[0032] The present application uses the identification of the track joint beacon for positioning, and the track joint beacon is not easy to deform, so that the obtained positioning result is more accurate.

[0033] The IMU used in the application has low cost and large error, but the application processes the positioning result by using the extended Kalman filtering algorithm, and realizes accurate positioning by using the combined positioning method of the track joint beacon and the inertial navigation, so as to reduce the positioning error, and therefore the application realizes high-precision positioning even by using the device with low cost and large error.

[0034] The application provides a monorail crane positioning method combining a track joint beacon and inertial navigation, combines an odometer and an extended Kalman filtering algorithm, and integrates the identification and positioning of the track joint beacon, so as to effectively reduce the cumulative error of the strapdown inertial navigation system, improve the positioning precision, and save the positioning cost. BRIEF DESCRIPTION OF DRAWINGS

[0035] In order to more clearly illustrate the technical solutions in the embodiments of the present application or the prior art, the following will briefly introduce the drawings needed to be used in the embodiments or the prior art description. Obviously, the drawings in the following description only some embodiments of the present application, and for those skilled in the art, other drawings can be obtained without creative labor on the basis of these drawings.

[0036] Fig. 1 is a structural schematic diagram of a monorail crane positioning method combining a track joint beacon and inertial navigation provided by the embodiment of the present application;

[0037] Fig. 2 is a first track joint judgment model flow chart;

[0038] Fig. 3 is a r+1 (r≥1) track joint judgment model flow chart;

[0039] Fig. 4 is a position calibration schematic diagram based on beacon identification. DETAILED DESCRIPTION

[0040] The technical solutions in the embodiments of the present application will be described clearly and completely below with reference to the drawings in the embodiments of the present application. Obviously, the described embodiments are only some embodiments of the present application, not all embodiments. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without creative labor are within the scope of protection of the present application.

[0041] As shown in Fig. 1, a monorail crane positioning method combining a track joint beacon and inertial navigation includes the following steps:

[0042] Step one: according to the data obtained by the encoder installed on the driving wheel of the monorail crane, a monorail crane odometer kinematic model is established, and the forward speed, heading angle and heading angle speed information of the monorail crane are obtained by solving the kinematic model.

[0043] Step two: according to the data obtained by the strapdown inertial navigation system mounted on the monorail crane, the strapdown inertial navigation is solved to obtain the attitude, velocity and position information of the monorail crane.

[0044] Step three: the heading data solved based on the kinematic model of the odometer and the heading angle solved by the strapdown inertial navigation are fused by using the extended Kalman filtering algorithm to obtain the combined positioning result of the inertial navigation and the odometer.

[0045] Step four: the beacons are arranged at the rail joints of the monorail crane, the numbers of the beacons and the specific position information at each beacon are determined according to the rail installation diagram of the monorail crane, and the transportation route of the monorail crane is divided into several driving sections by using the position information determined by the beacons.

[0046] As shown in FIG. 4, according to the rail installation diagram and the number of rail joints in the entire running route, the rail joint beacons are sequentially numbered as N1, N2, N3, …, Nm. m , wherein m is the total number of rail joint beacons; combined with the position coordinates (x i , y i , z i ) of the i-th rail joint in the rail installation diagram, each beacon is marked as Bea i = (N i , x i , y i , z i ), and the rail length between the rail joint beacon numbered N i and the previous rail joint beacon is defined as L i ; according to the running route, the joints beacons in the path are numbered as n1, n2, n3, …, n j , … in running order, and the rail joint beacons in the running route are marked as R j _Bea i = (n j , N i , x i , y i , z i ); the driving distance between the monorail crane departure position and the joint beacon n1 is Y1, and the rail length between the joint beacon n k and the joint beacon n k+1 is Y k+1 .

[0047] Step five: a vibration sensor is installed at the driving wheel of the monorail crane, the vibration signals in the driving process of the monorail crane are collected by using the vibration sensor, and the collected vibration signals are processed to identify the vibration impact signals in the driving process.

[0048] Step Six: Based on the information collected by the strapdown inertial navigation system and encoder, and combined with the track installation diagram, construct a track joint judgment model. Set an appropriate threshold according to the length of the track, judge the extracted pulse signals, filter out the impact signals that meet the requirements, namely the impact signals at the track joint beacon, and number the identified impact signals at the track joint beacon.

[0049] As shown in Figure 2, the specific steps for judging and screening the impact signal of the first track joint are as follows:

[0050] First, the threshold value set for the monorail in the first sub-section is BD1 = (0.9~1.1)·Y1. It is determined whether the travel distance R_S1(t) = S1(t)-0 of the impact signal I1 in the first sub-section meets the set threshold condition. If it meets the condition 0.9·Y1≤R_S1(t)≤1.1·Y1, then the impact signal I1 is the impact signal at the first rail joint in the travel route, and is numbered n1'.

[0051] If the threshold condition is not met, verify I2, I3, ..., I using the same method. k Until the condition is met, and the impact signal I that meets the condition is... p It is written as I1' = (I p ,n1',t).

[0052] As shown in Figure 3, the specific steps for judging and filtering the impact signal of the (r+1)th track joint are as follows:

[0053] Given I r '=(I q ,n r If ',t), then the threshold value for the (r+1)th subinterval is BD. r+1 = (0.9~1.1)·Y r+1 Determine the impact signal I q+1 The driving distance R_S in the (r+1)th sub-interval q+1 (t)=S q+1 (t)-S q (t) Whether the threshold condition is met, if it is met, 0.9·Y r+1 ≤R_S q+1 (t)≤1.1·Y r+1 Then the impact signal I q+1 The impact signal at the (r+1)th track joint in the travel route, numbered n r+1 ';

[0054] If the threshold condition is not met, verify I in the same way. q+2 ,I q+3 ,…,I k, until the condition is satisfied, and the impact signal I q is denoted as I r+1 ' = (I q+1 , n r+1 , t).

[0055] Step seven: using the identified track joint beacon number, combining the track installation diagram of each beacon number and the specific position of each beacon, using the number to match, get the time and position coordinate sequence of the monorail crane running to the track joint.

[0056] Step eight: establish a combined positioning model of track joint beacon and strapdown inertial navigation, use the absolute positioning information obtained by combining the track joint beacon identification judgment and the track installation diagram to realize the phased calibration and reset of the monorail crane positioning information, realize the combination of local relative positioning and global absolute positioning of the monorail crane.

[0057] Obviously, those skilled in the art can make various modifications and variations to the present application without departing from the spirit and scope of the present application. Thus, if these modifications and variations of the present application fall within the scope of the claims of the present application and their equivalents, the present application also intends to include these modifications and variations.

Claims

1. A monorail car positioning method using a combination of track joint beacons and inertial navigation, characterized by, The method comprises the following steps: S1: install an encoder on the driving wheel of the monorail crane, and establish a monorail odometer kinematic model according to the encoder data, so as to obtain the forward speed, heading angle and heading angle velocity information of the monorail crane; S2: obtain the attitude, velocity and position information of the monorail crane by performing strapdown inertial navigation calculation according to the data obtained by the strapdown inertial navigation system installed on the monorail crane; S3: fuse the heading data calculated based on the monorail odometer kinematic model and the heading angle obtained by the strapdown inertial navigation calculation by using an extended Kalman filtering algorithm, so as to obtain the inertial navigation and odometer combined positioning result; S4: set beacons at the track joints of the monorail crane, determine the numbers of the beacons and the specific position information at the beacons according to the track installation diagram of the monorail crane, and divide the transportation route of the monorail crane into a plurality of driving sections by using the position information determined by the beacons; S5: install a vibration sensor at the driving wheel of the monorail crane, collect the vibration signals in the driving process of the monorail crane by using the vibration sensor, and perform signal processing on the collected vibration signals to identify the vibration impact signals in the driving process; S6: construct a track joint judgment model based on the information collected by the strapdown inertial navigation system and the encoder, set a suitable threshold value according to the length of the track, judge the extracted pulse signals, screen out the impact signals meeting the requirements, i.e. the impact signals at the track joint beacons, and number the identified impact signals at the track joint beacons; S7: match the numbers of the identified track joint beacons with the numbers and specific positions of the beacons in the track installation diagram by using the numbers, so as to obtain the time and position coordinate sequence of the monorail crane running to the track joint; S8: establish a combined positioning model of the track joint beacons and the strapdown inertial navigation system, use the absolute positioning information obtained by combining the identification and judgment of the track joint beacons with the track installation diagram to realize the periodic calibration and resetting of the positioning information of the monorail crane, and realize the combination of the local relative positioning and the global absolute positioning of the monorail crane.

2. A monorail car positioning method using a rail joint beacon and an inertial navigation system combination as recited in claim 1, wherein, In step S3, the single-track crane primary positioning result FPR is obtained by using an extended Kalman filtering algorithm t =(t, x0, y0, z0), wherein t is the time of the positioning result, x, y, and z are the coordinates of the single-track crane.

3. A monorail car positioning method using a rail joint beacon and an inertial navigation system combination as recited in claim 2, wherein, In step S4, the rail joint beacons are numbered in sequence according to the monorail installation map and the number of monorail rail joint in the entire running route, respectively N1, N2, N3, …, Nm. m Wherein m is the total number of rail joint beacons; the position coordinates (x i ,y i ,z i ) of the i-th rail joint in the rail installation map are combined to mark each beacon as Bea i =(N i ,x i ,y i ,z i ), and the guide rail length between the rail joint beacon numbered N i and the previous rail joint beacon is defined as L i .

4. A monorail car positioning method using a rail joint beacon and an inertial navigation system combination as recited in claim 3, wherein, In step S5, the collected signal is pre-processed and filtered to remove noise interference, and peak value detection is performed on the signal. The process of one-time departure to parking of the monorail crane is set as an interval. In one interval, the average value P of the peak value of the pre-processed signal is set as a threshold value. If the peak value V P of the signal x(t) exceeds the set threshold value P, the signal is recorded as an impact signal X(t).

5. A monorail car positioning method using a rail joint beacon and an inertial navigation system combination as recited in claim 4, wherein, In step S6, the threshold value of the judgment model is set as follows: According to the single-track crane attitude, speed and position information obtained by the strapdown inertial navigation solution, a single-track crane running route is obtained; the encoder is used to collect the mileage of the single-track crane running, denoted as S(t), and the impact signal X(t) extracted in step S5 is matched with the mileage S(t) by using a time stamp, denoted as impact signal I k =(X(t),S k (t)), wherein k is the serial number of the impact signal according to time sorting. Bea beacons for each track joint along the running route are obtained from the track installation diagram. i And the length of each track is L i The beacons at each junction along the route are numbered sequentially as n1, n2, n3, ..., n according to the operational order. j ..., let R be the beacon for each track joint in the running route. j _Bea i =(n j N i ,x i ,y i ,z i Let Y1 be the travel distance between the monorail departure position and the joint beacon n1, and let n be the distance between the joint beacon n1 and the joint beacon n1. k With connector beacon n k+1 The orbital length between them is Y k+1 ; The running route of the monorail crane is divided into subintervals with lengths of Y1, Y2,..., Yn by using each joint beacon j , and each interval threshold in the judgment model is set as BD k =(0.9-1.1)·Y k .

6. A monorail car positioning method of a rail joint beacon and inertial navigation system combination as claimed in claim 5, wherein, In step S6, the specific steps of judging and screening the impact signals in the judgment model are as follows: Firstly, the set threshold value of the monorail crane in the first sub-interval is BD1=(0.9-1.1)·Y1, and whether the driving distance R_S1(t)=S1(t)-0 of the impact signal I1 in the first sub-interval meets the set threshold condition is judged, if 0.9·Y1≤R_S1(t)≤1.1·Y1 is met, the impact signal I1 is the impact signal at the first track joint in the driving route, and is numbered as n1'. If the threshold condition is not met, the same method is used to verify I2, I3,..., In, until the condition is met, and the impact signal I k that meets the condition is noted as I1' = (I p , n1', t). p , n1', t). Known I r = (I q , t) = S r , t) = S r+1 = (0.9 ~ 1.1) · Y r+1 , t) = S q+1 R_S q+1 (t) = S q+1 (t) = S q (t) = S r+1 = (0.9 ~ 1.1) · Y q+1 = (0.9 ~ 1.1) · Y r+1 = (0.9 ~ 1.1) · Y q+1 = (0.9 ~ 1.1) · Y r+1 = (0.9 ~ 1.1) · Y If the threshold condition is not satisfied, the same method is used to sequentially verify I q+2 , q+3 ,…,I k , until the condition is satisfied, and the impact signal I q that satisfies the condition is recorded as I r+1 ' = (I q+1 ,n r+1 , t).

7. A monorail car positioning method using a rail joint beacon and an inertial navigation system combination as recited in claim 6, wherein, In step S7, the beacons R of each track joint along the running route are identified by their numbers. j _Bea i =(n j N i ,x i ,y i ,z i ) and the impact signal I at the track joint obtained by screening through the matching model r+1 '=(I q+1 ,n r+1 Match ',t) and if r+1=j, then let I r+1 'With R j _Bea i Matching yields the time-coordinate sequence F of the monorail crane's journey to the track joint. ti _Bea i =(t,x i ,y i ,z i ).

8. A monorail car positioning method using a rail joint beacon and an inertial navigation system combination as recited in claim 7, wherein, In step S8, the time is used to match the monorail crane primary positioning result FPR t = (t, x0, y0, z0) and the time-coordinate sequence F ti _Bea i = (t, x i , y i , z i ) of the monorail crane running to the rail joint, if ti = t, the positioning information in F ti _Bea i is used to correct the position information of FPR t , so as to realize the stage calibration and resetting of the monorail crane positioning information.

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