Magnetic navigation signal processing method and system

Abstract

The invention discloses a magnetic navigation signal processing method and system, and belongs to the field of AGVs. The method comprises the following steps: acquiring a current control instruction of the AGV, wherein the current control instruction comprises straight movement, left turning and right turning; meanwhile, N magnetic navigation sensors arranged on the AGV are controlled to collect magnetic navigation signals, each magnetic navigation signal comprises N detection signals, and detection values of at least two continuous and true detection signals form a signal group; calculating a sensor center value as a vehicle center value; recording the information of each signal group in the form of a two-dimensional array; and according to the current control instruction of the AGV, the information recorded by each signal group and the central value of the sensor, screening out a correct signal group as a magnetic navigation signal. The accuracy and reliability of the magnetic navigation signal are improved.

Description

Technical Field

[0001] The present invention belongs to the field of AGV. Specifically, the present invention relates to a magnetic navigation signal processing method and system. Background Art

[0002] Magnetic navigation AGV (Automated Guided Vehicle) has accurate positioning, simple and reliable guiding principle. Thanks to the convenient laying process of magnetic strips, it is easier to change or expand the path, has no interference with sound and light, low cost, and strong stability in a complex factory environment. It has been widely used in various links of material distribution, finished product and semi-finished product transfer on the production line.

[0003] When a magnetic navigation AGV works, it often needs to judge its posture to ensure the stability of the vehicle. For example, a published document with the publication number CN117762145A, publication date: 2024.03.26, and patent name "A Pose Correction Method for Magnetic Navigation AGV" discloses a pose correction method for magnetic navigation AGV. The entire AGV motion space is incorporated into a rectangular coordinate system, each node is assigned a coordinate value, and the topological map composed of previous topological nodes is transformed into a two-dimensional digital map; in the two-dimensional digital map, speed planning is performed on the AGV on the motion path according to the AGV operation parameters; according to the speed planning result, the rotational speed of the steering wheel motor is controlled to correct the pose of the AGV.

[0004] However, for the above-mentioned published documents, the premise for the AGV to correct its pose is to have accurate and reliable magnetic navigation signals. However, in the actual working process, due to the influence of magnetic strip laying process, metal debris and magnetic strip fragments at the project site, etc., the detection effect of the magnetic navigation sensor is affected, and phenomena such as signal faults and losses are likely to occur. When phenomena such as signal loss and fault occur in the magnetic navigation signal, it may lead to unstable vehicle operation and is not conducive to vehicle safety.

[0005] Therefore, the present invention proposes a magnetic navigation signal processing method and system. Summary of the Invention

[0006] The present invention aims to overcome the deficiencies of the prior art and proposes a magnetic navigation signal processing method and system to achieve the following objectives: improve the accuracy and reliability of magnetic navigation signals.

[0007] To achieve the above objectives, the technical solution adopted by the present invention is: a magnetic navigation signal processing method, the method comprising the following steps:

[0008] Step S1, obtain the current control command of the AGV vehicle, including going straight, turning left, and turning right; at the same time, control N magnetic navigation sensors arranged on the AGV vehicle to collect magnetic navigation signals. Each magnetic navigation signal includes N detection signals, and the detection value of each detection signal is defined as Xm, and:

[0009] Xm = m, where m = 1, 2, 3, ..., N;

[0010] Among them, at least two consecutive and true detection values form a signal group;

[0011] Step S2: Calculate the sensor center value as the vehicle center value;

[0012] Step S3: For each signal group, record its information in the form of a two-dimensional array. The information to be recorded includes the number of each signal group, the starting detection value, the ending detection value, the signal group center value, the vehicle body deviation value, and the absolute value of the vehicle body deviation.

[0013] Step S4: According to the current control instruction of the AGV vehicle, the information recorded in each signal group, and the sensor center value, select a correct signal group.

[0014] Preferably, in step S1, it is judged whether the magnetic navigation signal is normal. If the magnetic navigation signal is lost and not restored within a preset duration, it is judged that the vehicle deviates from the track, and the previous signal processing result is maintained and a parking alarm is given; if the magnetic navigation signal is normal, the next step is continued.

[0015] Preferably, in step S2, the sensor center value = (1 + N) / 2, where the sensor center value represents half of the sum of the first detection value and the Nth detection value when the detection values of the N detection signals collected by the sensor are all true.

[0016] Preferably, in step S3, the data format of the two-dimensional array is as follows:

[0017] One-dimensional: Used to record the current signal group number;

[0018] Two-dimensional: Used to record the starting detection value, the ending detection value, the signal group center value, the vehicle body deviation value, and the absolute value of the vehicle body deviation in the current signal group.

[0019] Preferably, in step S3:

[0020] The starting detection value represents the first of the consecutive multiple detection values in the current signal group;

[0021] The ending detection value represents the last of the consecutive multiple detection values in the current signal group;

[0022] The signal group center value = (starting detection value + ending detection value) / 2;

[0023] The vehicle body deviation value = sensor center value - signal group center value;

[0024] The absolute value of the vehicle body deviation = |sensor center value - signal group center value|.

[0025] Preferably, when the vehicle body deviation value is greater than 0, it indicates that the vehicle center is on the right side of the magnetic stripe; when the vehicle body deviation value is less than 0, it indicates that the vehicle center is on the left side of the magnetic stripe.

[0026] Preferably, in the step S4, when the current control instruction of the AGV vehicle is to go straight, the signal group with the smallest absolute value of the vehicle body deviation among all signal groups is used as the correct signal group.

[0027] Preferably, in the step S4, when the current control instruction of the AGV vehicle is to turn left:

[0028] If the number of signal groups is less than or equal to two, it is regarded as no interference signal. At this time, the signal group with the smallest vehicle body deviation value is used as the correct signal group;

[0029] If the number of signal groups is greater than two, it is regarded as having interference signals. At this time, the signal group with the smallest absolute value of the vehicle body deviation among all signal groups with a vehicle body deviation value less than 0 is used as the correct signal group.

[0030] Preferably, in the step S4, when the current control instruction of the AGV vehicle is to turn right:

[0031] If the number of signal groups is less than or equal to two, it is regarded as no interference signal. At this time, the signal group with the largest vehicle body deviation value is used as the correct signal group;

[0032] If the number of signal groups is greater than two, it is regarded as having interference signals. At this time, the signal group with the smallest absolute value of the vehicle body deviation among all signal groups with a vehicle body deviation value greater than 0 is used as the correct signal group.

[0033] Meanwhile, the present application also proposes a magnetic navigation signal processing system, which is characterized in that: the system includes a controller and a magnetic navigation sensor, the controller is connected to the magnetic navigation sensor, wherein, the magnetic navigation sensor is used to collect magnetic navigation signals and send them to the controller; the controller is used to process magnetic navigation signals according to the method described in the present application.

[0034] The technical effects of the present invention are as follows:

[0035] (1) By combining the current control instruction of the AGV vehicle, the information recorded in each signal group, and the sensor center value, the present invention can overcome the influence of interference signals, obtain magnetic navigation signals composed of correct signal groups, and thus improve the accuracy and reliability of magnetic navigation signals.

[0036] (2) The present invention uses multi-dimensional arrays to summarize and statistically analyze magnetic navigation information, which can save all signals emitted by the sensor. At the same time, the multi-dimensional arrays also facilitate the subsequent loop comparison algorithm.

[0037] (3) The present invention converts multiple data bits of the magnetic navigation sensor into multiple detection signals, directly operates on multiple data bits of the magnetic navigation sensor, reduces programming code, improves program readability, and is easy to implement.

[0038] (4) The present invention uses digital numbers as the detection values of the detection signals, corresponding to the position information of magnetic navigation, and analyzes the vehicle body deviation with this, which is convenient for the upper controller to control more precisely. Description of the Drawings

[0039] Figure 1 It is a flowchart of a magnetic navigation signal processing method provided by an embodiment of the present invention;

[0040] Figure 2 It is a schematic diagram of magnetic navigation signal acquisition when driving straight and there are interference signals provided by an embodiment of the present invention;

[0041] Figure 3 It is a schematic diagram of magnetic navigation signal acquisition when turning left provided by an embodiment of the present invention; wherein: Figure 3 (1) represents no interference signal; Figure 3 (2) represents the existence of interference signals;

[0042] Figure 4 It is a schematic diagram of magnetic navigation signal acquisition when turning right provided by an embodiment of the present invention; wherein: Figure 4 (1) represents no interference signal; Figure 4 (2) represents the existence of interference signals; Detailed Embodiments

[0043] The following is a further detailed description of the specific embodiments of the present invention by describing the embodiments with reference to the drawings, aiming to help those skilled in the art have a more complete, accurate, and in-depth understanding of the inventive concept and technical solution of the present invention, and facilitate its implementation. It should be noted that the terms "first", "second", etc. used in this application are only for conveniently describing the technical solution to distinguish different components, and do not limit this application. To make the technical solution of the present invention clearer, the present invention is explained and illustrated through the following embodiments.

[0044] A magnetic navigation sensor is provided on the magnetic navigation AGV and is guided according to the laid magnetic strip. When the vehicle is driving normally, the magnetic strip is on the longitudinal central axis of the vehicle. Generally, the magnetic navigation sensor is installed at the bottom of the vehicle body, and the line segment where each detection point is located is perpendicular to the longitudinal central axis of the vehicle body, and the center of the line segment where each detection point is located falls on the longitudinal central axis of the vehicle body.

[0045] The magnetic navigation sensor model adopted in this embodiment is IGK-G410, which is a 16-bit magnetic navigation sensor, with a total of 16 detection points and can output 16 detection signals simultaneously.

[0046] To overcome the influence of interference signals generated by metal debris, magnetic strip fragments, etc. at the project site, so as to obtain correct magnetic navigation signals, and then correctly judge the attitude of the vehicle during driving, this embodiment provides a magnetic navigation signal processing method, as Figure 1 shown, the method includes the following steps:

[0047] Step S1: Obtain the current control instructions of the AGV vehicle, including going straight, turning left, and turning right; at the same time, control the N magnetic navigation sensors arranged on the AGV vehicle to collect magnetic navigation signals. Each magnetic navigation signal includes N detection signals, and the detection value of each detection signal is defined as Xm, and:

[0048] Xm = m, m = 1, 2, 3,..., N;

[0049] Among them, at least two consecutive detection values that are true (the corresponding value is true when the detected magnetic field change exceeds the preset threshold) form a signal group;

[0050] Step S2: Calculate the sensor center value as the vehicle center value;

[0051] Step S3: For each signal group, record its information in the form of a two-dimensional array. The information to be recorded includes the number, start detection value, end detection value, signal group center value, vehicle body deviation value, and absolute value of vehicle body deviation of each signal group;

[0052] Step S4: According to the current control instruction of the AGV vehicle, the information recorded by each signal group, and the sensor center value, select a correct signal group.

[0053] Specifically, in step S1 of this embodiment, the vehicle normally keeps going straight according to the straight-ahead instruction of the controller. When encountering a fork in the road for turning left or right, the vehicle drives the vehicle to turn left, turn right, or keep going straight in real time according to the current control instruction. In any working condition, it is necessary to filter and screen the magnetic navigation signals to obtain the vehicle deflection information that conforms to the control instruction.

[0054] In addition, to ensure vehicle safety, in step S1 of this embodiment, when collecting magnetic navigation signals, it will judge whether the magnetic navigation signals are normal. If the magnetic navigation signals are lost and not restored within the preset duration (set to 5s in this embodiment, and can be flexibly selected according to actual needs during specific implementation), it is judged that the vehicle deviates from the track, and the previous signal processing result is maintained and a parking alarm is given; if the magnetic navigation signals are normal, the next step is continued.

[0055] As Figure 2As shown, a magnetic navigation signal collected in this embodiment includes 16 detection signals (corresponding to the number of sensor bits). That is, multiple data bits of the magnetic navigation sensor are converted into multiple detection signals, and the multiple data bits of the magnetic navigation sensor are directly operated on, reducing programming code, improving program readability, and being easy to implement. The detection value of each detection signal is defined as Xm, and:

[0056] Xm = m, where m = 1, 2, 3,..., 16;

[0057] That is, from left to right, the detection values of each detection signal are 1 to 16 in sequence. That is, digital numbers are used as the detection values of the detection signals, corresponding to the position information of magnetic navigation, so as to analyze the vehicle body deviation and facilitate the upper-layer controller to control more precisely.

[0058] For another example Figure 2 As shown, due to the existence of interference signals, there are 3 groups of consecutive and true signals in the collected magnetic navigation signals, which are (2, 3, 4), (6, 7, 8, 9), and (14, 15) respectively.

[0059] Next, in step S2 of this embodiment, the center value of the sensor is determined as the vehicle center value, so that the vehicle attitude can be judged according to the deviation between the center value of the correct signal group and the sensor center value during actual operation. The calculation of the sensor center value is as follows:

[0060] Sensor center value = (1 + N) / 2, where the sensor center value represents half of the sum of the first detection value and the Nth detection value when the detection values of N detection signals collected by the sensor are all true. In this embodiment, the sensor center value = (1 + 16) / 2 = 8.5.

[0061] During the actual magnetic navigation signal processing process, multiple signal groups will be generated, and each signal group involves different magnetic navigation information. For the convenience of information recording and management, this embodiment uses a multi-dimensional array to summarize and count the magnetic navigation information, which can save all the signals sent by the sensor, and at the same time the multi-dimensional array also provides convenience for subsequent loop comparison algorithms.

[0062] In step S3 of this embodiment, a 2D array is adopted, and its data format is as follows:

[0063] One-dimensional: used to record the current signal group number; the number of (2, 3, 4) is 1, the number of (6, 7, 8, 9) is 2, and the number of (14, 15) is 3;

[0064] Two-dimensional: used to record the starting detection value, ending detection value, signal group center value, vehicle body deviation value, and absolute value of vehicle body deviation in the current signal group. Specifically:

[0065] The starting detection value represents the first of a series of consecutive detection values in the current signal group; for example, for the signal group (2, 3, 4), the starting detection value is 2.

[0066] The ending detection value represents the last of a series of consecutive detection values in the current signal group; for example, for the signal group (2, 3, 4), the ending detection value is 4.

[0067] The center value of the signal group = (starting detection value + ending detection value) / 2; for example, for the signal group (2, 3, 4), the center value of the signal group = (2 + 4) / 2 = 3.

[0068] The body deviation value = sensor center value - signal group center value; for example, for the signal group (2, 3, 4), the body deviation value = 8.5 - 3 = 5.5.

[0069] The absolute value of the body deviation = |sensor center value - signal group center value|; for example, for the signal group (2, 3, 4), the absolute value of the body deviation = |8.5 - 3| = 5.5.

[0070] When there is no interference signal, the attitude of the vehicle can be judged according to the body deviation value, that is: when the body deviation value is greater than 0, it means that the vehicle center is on the right side of the magnetic stripe; when the body deviation value is less than 0, it means that the vehicle center is on the left side of the magnetic stripe. However, due to the existence of interference signals, it is also necessary to make a comprehensive judgment based on the current control instruction of the AGV vehicle, the information recorded in each signal group, and the sensor center value.

[0071] Specifically, in step S4 of this embodiment:

[0072] When the current control instruction of the AGV vehicle is to go straight, the signal group with the smallest absolute value of the body deviation among all signal groups is taken as the correct signal group. As Figure 2 shown, the three signal groups of a magnetic navigation signal are (2, 3, 4), (7, 8, 9, 10), and (14, 15) respectively, and their absolute values of the body deviation are 5.5, 0, and 6 respectively. Then (7, 8, 9, 10) is taken as the correct signal group. At this time, the body deviation value is exactly 0, the vehicle center coincides with the magnetic stripe, and the vehicle does not deviate.

[0073] When the current control instruction of the AGV vehicle is to turn left:

[0074] If the number of signal groups is less than or equal to two, it is regarded as no interference signal. At this time, the signal group with the smallest body deviation value is taken as the correct signal group. As Figure 3As shown in (1), the two signal groups of a magnetic navigation signal are (4, 5, 6) and (9, 10, 11) respectively, and the two vehicle body deviation values are 3.5 and -1.5 respectively. Then, (9, 10, 11) is taken as the correct signal group. At this time, the vehicle body deviation value is -1.5, which is less than 0, indicating that the vehicle center is on the left side of the magnetic stripe, meaning the vehicle is currently turning left.

[0075] If the number of signal groups is greater than two, it is regarded as having interference signals. At this time, the signal group with the smallest absolute value of the vehicle body deviation among all signal groups with a vehicle body deviation value less than 0 is taken as the correct signal group. For example, Figure 3 As shown in (2), the three signal groups of a magnetic navigation signal are (1, 2, 3), (5, 6, 7), and (12, 13, 14) respectively. The vehicle body deviation values of the three signal groups are 6.5, 2.5, and -4.5 respectively, and the absolute values of the vehicle body deviation are 6.5, 2.5, and 4.5 in sequence. Then, (12, 13, 14) is selected as the correct signal group. At this time, the vehicle body deviation value is -4.5, which is less than 0, indicating that the vehicle center is on the left side of the magnetic stripe, meaning the vehicle is currently turning left.

[0076] When the current control instruction of the AGV vehicle is to turn right:

[0077] If the number of signal groups is less than or equal to two, it is regarded as having no interference signals. At this time, the signal group with the largest vehicle body deviation value is taken as the correct signal group; for example, Figure 4 As shown in (1), the two signal groups of a magnetic navigation signal are (3, 4, 5) and (8, 9, 10) respectively, and the two vehicle body deviation values are 4.5 and -0.5 respectively. Then, (3, 4, 5) is taken as the correct signal group. At this time, the vehicle body deviation value is 4.5, which is greater than 0, indicating that the vehicle center is on the right side of the magnetic stripe, meaning the vehicle is currently turning right.

[0078] If the number of signal groups is greater than two, it is regarded as having interference signals. At this time, the signal group with the smallest absolute value of the vehicle body deviation among all signal groups with a vehicle body deviation value greater than 0 is taken as the correct signal group. For example, Figure 4 As shown in (2), the three signal groups of a magnetic navigation signal are (3, 4, 5), (8, 9, 10), and (14, 15, 16) respectively. The vehicle body deviation values of the three signal groups are 4.5, -0.5, and -6.5 respectively, and the absolute values of the vehicle body deviation are 4.5, 0.5, and 6.5 in sequence. Then, (3, 4, 5) is selected as the correct signal group. At this time, the vehicle body deviation value is 4.5, which is greater than 0, indicating that the vehicle center is on the right side of the magnetic stripe, meaning the vehicle is currently turning right.

[0079] Finally, after selecting the correct signal group, the body deviation value recorded by it is used for subsequent body attitude adjustment, improving the accuracy and reliability of the magnetic navigation signal. The present invention effectively excludes interference signals, effectively avoids the instability of body control caused by misdetection of the magnetic navigation sensor, and further improves the adaptability of the AGV vehicle in complex environments.

[0080] Meanwhile, according to the above magnetic navigation signal processing method, this embodiment proposes a magnetic navigation signal processing system, which includes a controller and a magnetic navigation sensor. The controller is connected to the magnetic navigation sensor. Among them, the magnetic navigation sensor is used to collect magnetic navigation signals and send them to the controller; the controller is used to process magnetic navigation signals according to the magnetic navigation signal processing method of the present invention.

[0081] Specifically, the controller of this embodiment can select the Siemens S7-1200 series PLC, and use the SCL statement to convert the magnetic navigation signal processing method of the present invention into PLC language, so as to realize the magnetic navigation signal processing based on the PLC.

[0082] The present invention has been described exemplarily in combination with the accompanying drawings. Obviously, the specific implementation of the present invention is not limited by the above methods. As long as various non-substantive improvements are made by adopting the method concept and technical solution of the present invention; or without improvement, the above concept and technical solution of the present invention are directly applied to other occasions, they are all within the protection scope of the present invention.

Claims

1. A magnetic navigation signal processing method, characterized in that: The method includes the following steps: Step S1: Obtain the current control instructions of the AGV vehicle, including going straight, turning left, and turning right; at the same time, control the N magnetic navigation sensors arranged on the AGV vehicle to collect magnetic navigation signals. Each magnetic navigation signal includes N detection signals, and the detection value of each detection signal is defined as Xm, and: Xm = m, m = 1, 2, 3,..., N; Among them, at least two consecutive detection values that are true form a signal group; Step S2: Calculate the sensor center value as the vehicle center value; Step S3: For each signal group, record its information in the form of a two-dimensional array. The information to be recorded includes the number of each signal group, the starting detection value, the ending detection value, the signal group center value, the vehicle body deviation value, and the absolute value of the vehicle body deviation; Step S4: According to the current control instruction of the AGV vehicle, the information recorded by each signal group, and the sensor center value, select a correct signal group.

2. The magnetic navigation signal processing method according to claim 1, wherein: In the step S1, determine whether the magnetic navigation signal is normal. If the magnetic navigation signal is lost and not restored within a preset duration, it is determined that the vehicle deviates from the track, and the previous signal processing result is maintained and a parking alarm is issued; if the magnetic navigation signal is normal, continue to execute the next step.

3. A magnetic navigation signal processing method according to claim 1, characterized in that: In the step S2, the sensor center value = (1 + N) / 2, where the sensor center value represents half of the sum of the first detection value and the Nth detection value when the detection values of the N detection signals collected by the sensor are all true.

4. A magnetic navigation signal processing method according to claim 1, characterized in that: In the step S3, the data format of the two-dimensional array is as follows: One-dimensional: Used to record the current signal group number; Two-dimensional: Used to record the starting detection value, the ending detection value, the signal group center value, the vehicle body deviation value, and the absolute value of the vehicle body deviation in the current signal group; 5. A magnetic navigation signal processing method according to claim 1 or 4, characterized in that: In the step S3: The starting detection value represents the first of the consecutive multiple detection values in the current signal group; The ending detection value represents the last of the consecutive multiple detection values in the current signal group; The signal group center value = (starting detection value + ending detection value) / 2; The vehicle body deviation value = sensor center value - signal group center value; The absolute value of the vehicle body deviation = |sensor center value - signal group center value|.

6. A magnetic navigation signal processing method according to claim 5, characterized in that: When the vehicle body deviation value is greater than 0, it means that the vehicle center is on the right side of the magnetic stripe; when the vehicle body deviation value is less than 0, it means that the vehicle center is on the left side of the magnetic stripe.

7. A magnetic navigation signal processing method according to claim 6, characterized in that: In the step S4, when the current control instruction of the AGV vehicle is going straight, select the signal group with the smallest absolute value of the vehicle body deviation among all signal groups as the correct signal group.

8. A magnetic navigation signal processing method according to claim 6, characterized in that: In the step S4, when the current control instruction of the AGV vehicle is turning left: If the number of signal groups is less than or equal to two, it is regarded as no interference signal. At this time, select the signal group with the smallest vehicle body deviation value as the correct signal group; If the number of signal groups is greater than two, it is regarded as having interference signals. At this time, select the signal group with the smallest absolute value of the vehicle body deviation among all signal groups with a vehicle body deviation value less than 0 as the correct signal group.

9. A magnetic navigation signal processing method according to claim 6, wherein: In the step S4, when the current control instruction of the AGV vehicle is turning right: If the number of signal groups is less than or equal to two, it is regarded as no interference signal. At this time, select the signal group with the largest vehicle body deviation value as the correct signal group; If the number of signal groups is greater than two, it is regarded that there is an interference signal. At this time, the signal group with the smallest absolute value of the vehicle body deviation among all signal groups with the vehicle body deviation value greater than 0 is used as the correct signal group.

10. A magnetic navigation signal processing system according to the method of any one of claims 1-9, characterized in that: The system includes a controller and a magnetic navigation sensor, and the controller is connected to the magnetic navigation sensor. Among them, the magnetic navigation sensor is used to collect magnetic navigation signals and send them to the controller; the controller is used to process the magnetic navigation signals according to the method described in any one of claims 1-9.

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