Dry bulk cargo warehouse detection vehicle positioning method, system and terminal based on LED light source

Abstract

The invention relates to the technical field of indoor positioning, and discloses a dry bulk warehouse detection vehicle positioning method, system and terminal based on an LED light source. A plurality of LED light sources are arranged in the dry bulk warehouse; the threshold range of the attitude angle of the detection vehicle is pre-configured; according to the positioning method, the detection vehicle is positioned in real time, firstly, the attitude angle of the detection vehicle is obtained, and the positioning mode is automatically switched based on the relation between the attitude angle and the threshold range; in other words, if the attitude angle is within the threshold range, positioning is carried out based on the LED light source, and if the attitude angle is not within the threshold range, positioning is carried out based on the INS; and taking the positioning result of the detection vehicle at the previous moment as an initial filtering value, dynamically adjusting the state vector of the output result of the positioning mode, and filtering the initial filtering value and the output result of the positioning mode based on a Kalman filtering algorithm to obtain a final positioning result of the detection vehicle. According to the invention, the problems of GPS signal loss, INS positioning error accumulation, high UWB / INS scheme cost and the like when the detection vehicle works indoors can be solved.

Description

Technical Field

[0001] The present invention relates to the field of indoor positioning technology, and in particular to a positioning method, system and terminal for a dry bulk cargo warehouse inspection vehicle based on an LED light source. Background Art

[0002] Standardized management is essential during the import, export and storage of grain. At present, grain silo management mainly relies on manual labor, which is highly repetitive and exposes workers to dust and grain movement, leading to significant health and safety hazards. In order to solve the inefficiency and safety problems of traditional manual management, the application of grain silo inspection vehicles has become a promising solution. Among them, the precise positioning of the inspection vehicle is crucial to optimizing the quality of the task and overall productivity. However, due to the lack of GPS signals in indoor environments, accurate positioning faces challenges. Most existing grain silo inspection vehicles rely on inertial navigation systems (INS) for positioning. Its working principle is to measure the acceleration and angular velocity of the object in the inertial space, and combine it with the initial position information to infer the current position.

[0003] However, since the working principle of INS is based on integral calculation, any tiny measurement error will accumulate over time, eventually leading to serious positioning deviation, namely "position drift". Therefore, the positioning accuracy of the granary inspection vehicle that relies solely on INS for positioning will gradually decrease with the increase of running time, and it is difficult to meet the long-term, high-precision positioning needs. The existing ultra-wideband (Ultra-Wideband, UWB) and INS fusion positioning technology has been derived. This solution can improve positioning accuracy, but it requires the installation of additional base stations, which undoubtedly increases the reconstruction cost and is easily affected by electromagnetic interference, thus affecting the actual application effect.

[0004] In view of this, it is urgent to propose a dry bulk warehouse inspection vehicle positioning method that is suitable for indoor work, has low cost and high positioning accuracy. Summary of the invention

[0005] The purpose of the present invention is to provide a positioning method, system and terminal for a dry bulk cargo warehouse inspection vehicle based on LED light source, which can solve the problems faced by the inspection vehicle when working indoors, such as lack of GPS signal, accumulation of INS positioning error and high cost of UWB / INS solution.

[0006] In order to achieve the above object, the present invention adopts the following technical scheme:

[0007] In a first aspect, the present invention provides a method for positioning a dry bulk cargo warehouse inspection vehicle based on an LED light source, wherein a plurality of LED light sources are provided in the dry bulk cargo warehouse; a threshold range of an attitude angle of the inspection vehicle is pre-configured; and the positioning method positions the inspection vehicle in real time, the positioning method comprising:

[0008] S1. Obtain the attitude angle of the detection vehicle and determine whether the attitude angle is within the threshold range; if so, execute S2; otherwise, execute S3;

[0009] S2. Positioning based on LED light source, specifically including the following sub-steps:

[0010] S20. Using light signals of different frequencies to identify each LED light source;

[0011] S21 demodulates the optical signal received by the detection vehicle, and determines the target LED light source emitting the optical signal based on the demodulated optical signal frequency;

[0012] S22. Calculate the distance between the detection vehicle and the target LED light source, and obtain the LED positioning result of the detection vehicle based on the distance;

[0013] S23 determines the initial filter value, dynamically adjusts the state vector of the LED positioning result, filters the initial filter value and the LED positioning result, and obtains the positioning result of the detection vehicle;

[0014] S3. Positioning based on INS, specifically including the following sub-steps:

[0015] S30. Determine the initial position of the detection vehicle, obtain the linear acceleration and angular velocity of the detection vehicle, perform an integral operation on the initial position, linear acceleration and angular velocity of the detection vehicle, and obtain the current speed and INS positioning result of the detection vehicle;

[0016] S31. Determine the initial filter value, dynamically adjust the state vector of the current speed and INS positioning result, filter the initial filter value, current speed, and INS positioning result, and obtain the positioning result of the detection vehicle.

[0017] As a possible implementation method, S23 and S31 are both implemented based on the Kalman filter algorithm, and the initial filter value is the positioning result of the detected vehicle at the last moment.

[0018] As a possible implementation method, S22 specifically includes:

[0019] S220. Use the following formula to calculate the distance between the detection vehicle and the target LED light source:

[0020]

[0021] Where m represents the Lambert radiation order, A represents the equivalent receiving area of ​​the photodiode, φ represents the angle between the incident light and the normal line of the photodiode surface, θ represents the angle of the emitted light from the LED light source, and T srepresents the transmittance of the LED light signal at the photodiode, P0 represents the received signal power from the LED light source to the photodiode, and P r It indicates the received power of the photodiode after passing through the optical material;

[0022] S221. Order The solution process in S220 is transformed into the following objective function:

[0023]

[0024] In the formula, S(x,y) represents the position coordinates of the detection vehicle, and N represents the number of LED light sources;

[0025] S222. Preset the number of iterations, use the quasi-Newton algorithm to solve the gradient and Hessian matrix of the above objective function, and update the LED positioning result iteratively. When the number of iterations reaches the preset number of iterations, stop the iteration to obtain the final LED positioning result.

[0026] As a possible implementation method, filtering processing includes a prediction process and an update process;

[0027] The prediction process is implemented as follows:

[0028] X k,k-1 =F k,k-1 X k-1 ,

[0029]

[0030] In the formula, k represents the kth moment, X k-1 is the state vector at time k-1, X k,k-1 is the predicted value of the state vector at time k, F k,k-1 is the state transfer matrix at time k, P k,k-1 represents the prediction of the covariance matrix at time k, Q k-1 represents the process noise covariance matrix at time k-1;

[0031] The update process is implemented as follows:

[0032]

[0033] X k =X k,k-1 +K k (z k -H k X k-1 ),

[0034]

[0035] In the formula, Hk represents the Kalman gain, z k represents the measurement vector, H k represents the observation matrix, R k represents the measurement noise covariance matrix, X k is the final updated state vector, P k is the conditional error covariance matrix at time k.

[0036] In a second aspect, the present invention provides a dry bulk cargo warehouse inspection vehicle positioning system based on LED light sources, comprising: an inertial navigation module, an LED positioning module, and a variable state dimension Kalman filter module based on attitude angle;

[0037] The inertial navigation module is installed on the inspection vehicle to obtain the linear acceleration and angular velocity of the inspection vehicle, integrate the initial position, linear acceleration and angular velocity of the inspection vehicle, and obtain the current speed, attitude angle and INS positioning result of the inspection vehicle;

[0038] The LED positioning module is used to demodulate the received optical signal, determine the target LED light source that transmits the optical signal based on the demodulated optical signal frequency, calculate the distance between the inspection vehicle and the target LED light source, and obtain the LED positioning result of the inspection vehicle;

[0039] The variable state dimension Kalman filter module based on attitude angle is used to switch the positioning method, determine the initial filtering value and filter the initial filtering value and the result output by the positioning method to obtain the positioning result of the detection vehicle.

[0040] As a possible implementation, the inertial navigation module includes a measurement unit and an INS positioning unit;

[0041] The measuring unit includes an accelerometer and a gyroscope. The accelerometer is used to obtain the linear acceleration of the detection vehicle, and the gyroscope is used to obtain the angular velocity of the detection vehicle.

[0042] The INS positioning unit is used to integrate the initial position, linear acceleration and angular velocity of the inspection vehicle to obtain the current speed, INS positioning result and attitude angle of the inspection vehicle.

[0043] As a possible implementation, the LED positioning module includes N LED light sources, a communication unit and an LED positioning unit, where N is greater than or equal to 3;

[0044] The communication unit includes a modulator, a photodiode and a demodulator. The modulator is used to identify each LED light source using light signals of different frequencies; the photodiode is used to receive the light signal; the demodulator is used to demodulate the received light signal and determine the target LED light source that transmits the light signal based on the frequency of the demodulated light signal;

[0045] The LED positioning unit is used to calculate the distance between the inspection vehicle and the target LED light source to obtain the LED positioning result of the inspection vehicle.

[0046] As a possible implementation, the attitude angle-based variable state dimension Kalman filter module includes a mode switching unit and a data filtering unit;

[0047] The mode switching unit automatically switches between LED light source-based positioning and INS-based positioning according to the judgment result of whether the attitude angle is within the threshold range; the data filtering unit is used to determine the positioning result of the detection vehicle at the last moment as the initial filtering value when the positioning method is switched, and filter the result output by the positioning method to obtain the positioning result of the detection vehicle.

[0048] As a possible implementation, a photodiode is installed on the inspection vehicle just above the inertial navigation module.

[0049] In a third aspect, the present invention provides a terminal including a processor and a communication interface coupled to the processor, wherein the processor is used to run a computer program or instruction to implement the dry bulk cargo warehouse inspection vehicle positioning method based on an LED light source provided in the first aspect.

[0050] Compared with the prior art, the beneficial effects of the present invention are:

[0051] 1. The dry bulk cargo warehouse inspection vehicle positioning method based on LED light source proposed in the present invention utilizes the existing LED light source in the dry bulk cargo warehouse as the positioning signal source, thereby solving the problem of reduced positioning accuracy due to the lack of indoor GPS signals. The present invention does not require the installation of an additional GPS receiver and is not affected by GPS signal obstruction or interference, thereby reducing system costs while ensuring stable and reliable operation in indoor environments such as cargo warehouses.

[0052] 2. Compared with the existing UWB and INS fusion positioning, the proposed method of positioning the dry bulk cargo warehouse inspection vehicle based on LED light source does not require the installation of an additional UWB base station, and directly uses the existing LED light source in the cargo warehouse as the positioning signal source, which greatly reduces the installation cost and maintenance cost of the system. At the same time, the anti-interference ability of the visible light signal is stronger than that of the UWB signal, and it can provide more stable positioning performance in complex electromagnetic environments such as dry bulk cargo warehouses. Therefore, the present invention is easier to promote and apply in dry bulk cargo warehouse environments.

[0053] 3. The dry bulk cargo warehouse inspection vehicle positioning method and positioning system based on LED light source proposed in the present invention introduces a variable state dimensional Kalman filter based on attitude angle, and uses the attitude angle as the decision condition for switching the positioning mode. When the attitude angle is within the threshold range, LED is used for positioning. When the attitude angle exceeds the threshold range, it automatically switches to INS positioning mode, realizing intelligent switching between LED positioning and INS positioning, and ensuring the continuity and robustness of positioning.

[0054] 4. When the mode is switched, the present invention uses the final positioning result of the previous positioning mode as the filtering starting value of the current positioning mode. According to different positioning modes, the state vector dimension is adaptively adjusted, the entire positioning process is filtered, and the LED and INS fusion positioning is realized. The LED positioning information is used to correct the INS positioning error, which effectively alleviates the problem of cumulative error in INS positioning and significantly improves the positioning accuracy. Even in the case of long-term operation, a high positioning accuracy can be maintained to adapt to different terrain conditions, such as ramps and obstacles in dry bulk warehouses. BRIEF DESCRIPTION OF THE DRAWINGS

[0055] The drawings described herein are used to provide a further understanding of the present invention and constitute a part of the present invention. The exemplary embodiments of the present invention and their descriptions are used to explain the present invention and do not constitute an improper limitation of the present invention. In the drawings:

[0056] Figure 1 This is a flow chart of a method for positioning a dry bulk cargo warehouse inspection vehicle based on an LED light source in an embodiment of the present invention;

[0057] Figure 2 A comparison diagram of positioning results obtained by experiments using five different positioning methods including the positioning method of the present invention in an embodiment of the present invention;

[0058] Figure 3 A comparison diagram of positioning results obtained by performing square trajectory experiments using five different positioning methods including the positioning method of the present invention in an embodiment of the present invention;

[0059] Figure 4 A comparison diagram of positioning results obtained by performing linear reciprocating motion experiments using five different positioning methods including the positioning method of the present invention in an embodiment of the present invention;

[0060] Figure 5 Schematic diagram of a dry bulk cargo warehouse inspection vehicle positioning system based on LED light sources in an embodiment of the present invention.

[0061] Reference numerals

[0062] 1- inertial navigation module, 10- measurement unit, 100- accelerometer, 101- gyroscope, 11- INS positioning unit;

[0063] 2-LED positioning module, 20-LED light source, 21-communication unit, 210-modulator, 211-photodiode, 212-demodulator, 22-LED positioning unit;

[0064] 3-variable state dimension Kalman filter module based on attitude angle, 30-mode switching unit, 31-data filtering unit. DETAILED DESCRIPTION

[0065] In order to clearly describe the technical solutions of the embodiments of the present invention, in the embodiments of the present invention, words such as "first" and "second" are used to distinguish the same items or similar items with basically the same functions and effects. For example, the first threshold and the second threshold are only used to distinguish different thresholds, and their order is not limited. Those skilled in the art can understand that words such as "first" and "second" do not limit the quantity and execution order, and words such as "first" and "second" do not necessarily limit them to be different.

[0066] It should be noted that, in the present invention, words such as "exemplary" or "for example" are used to indicate examples, illustrations or descriptions. Any embodiment or design described as "exemplary" or "for example" in the present invention should not be interpreted as being more preferred or more advantageous than other embodiments or designs. Specifically, the use of words such as "exemplary" or "for example" is intended to present related concepts in a specific way.

[0067] In the present invention, "at least one" means one or more, and "plurality" means two or more. "And / or" describes the association relationship of associated objects, indicating that three relationships may exist. For example, A and / or B can mean: A exists alone, A and B exist at the same time, and B exists alone, where A and B can be singular or plural. The character " / " generally indicates that the associated objects before and after are in an "or" relationship. The following at least one item (items) or similar expressions thereof refer to any combination of these items, including any combination of single items (items) or plural items (items). For example, at least one item (items) of a, b or c can mean: a, b, c, the combination of a and b, the combination of a and c, the combination of b and c, or the combination of a, b and c, where a, b, c can be single or multiple.

[0068] Due to the lack of GPS signals in indoor environments, most existing granary inspection vehicles rely on inertial navigation systems (INS) for positioning. However, the positioning accuracy of granary inspection vehicles that rely solely on INS for positioning will gradually decrease with the increase of operating time, and it is difficult to meet the long-term, high-precision positioning needs. Although the existing ultra-wideband (Ultra-Wideband, UWB) and INS fusion positioning technology can improve positioning accuracy, it requires the installation of additional base stations, which undoubtedly increases the reconstruction cost and is easily affected by electromagnetic interference, thus affecting the actual application effect.

[0069] In view of the above problems, the present invention proposes a positioning method, system and terminal for a dry bulk warehouse inspection vehicle based on LED light source, which can solve the problems faced by the inspection vehicle when working indoors, such as lack of GPS signal, accumulation of INS positioning error and high cost of UWB / INS solution.

[0070] In the first aspect, the present invention provides a method for positioning a dry bulk cargo warehouse inspection vehicle based on an LED light source, wherein the dry bulk cargo warehouse has a plurality of LED light sources; a threshold range of the inspection vehicle attitude angle is pre-configured; and the positioning method positions the inspection vehicle in real time, see Figure 1 , positioning methods include:

[0071] S1. Obtain the attitude angle of the detection vehicle and determine whether the attitude angle is within the threshold range; if so, execute S2; otherwise, execute S3;

[0072] As an example, in actual application, a gyroscope is used to measure the angular velocity of the inspection vehicle, and the measured angular velocity is integrated to obtain the attitude angle. The threshold range is obtained by multiple experiments based on the indoor space of an actual dry bulk cargo warehouse.

[0073] S2. Positioning based on LED light source, specifically including the following sub-steps:

[0074] S20. Using light signals of different frequencies to identify each LED light source;

[0075] S21 demodulates the optical signal received by the detection vehicle, and determines the target LED light source emitting the optical signal based on the demodulated optical signal frequency;

[0076] In actual application, a modulator is used to identify each LED light source using optical signals of different frequencies, and a demodulator is used to demodulate the optical signal received by the detection vehicle.

[0077] S22. Calculate the distance between the detection vehicle and the target LED light source, and obtain the LED positioning result of the detection vehicle based on the distance;

[0078] The present invention directly utilizes the existing LED light source in the dry bulk cargo warehouse as a positioning signal source, thereby solving the problem of reduced positioning accuracy due to the lack of indoor GPS signals. The present invention does not require the installation of an additional GPS receiver and is not affected by GPS signal obstruction or interference, thereby reducing system costs while ensuring stable and reliable operation in indoor environments such as cargo warehouses.

[0079] As a possible implementation method, S22 specifically includes:

[0080] S220. Use the following formula to calculate the distance between the detection vehicle and the target LED light source:

[0081]

[0082] Where m represents the Lambert radiation order, A represents the equivalent receiving area of ​​the photodiode, φ represents the angle between the incident light and the normal line of the photodiode surface, θ represents the angle of the emitted light from the LED light source, and T s represents the transmittance of the LED light signal at the photodiode, P0 represents the received signal power from the LED light source to the photodiode, and P r It indicates the received power of the photodiode after passing through the optical material;

[0083] In practical applications, positioning based on LED is only used when the attitude angle of the detection vehicle is within the threshold range. Therefore, in order to simplify the calculation, consider the state where the LED light source and the photodiode are facing each other, that is, the direction normals of the two coincide, then the above formula is converted into:

[0084]

[0085] S221. Order but: However, in real applications, the equation is not completely valid due to the influence of attitude angle, noise and other factors that affect the propagation of LED signals. In order to estimate the coordinates (x, y) of the detection vehicle, the problem is expressed as a minimization problem, so the solution process in S220 is converted into the following objective function:

[0086]

[0087] In the formula, S(x,y) represents the position coordinates of the detection vehicle, and N represents the number of LED light sources;

[0088] S222. Preset the number of iterations, use the quasi-Newton algorithm to solve the gradient and Hessian matrix of the above objective function, and update the LED positioning result iteratively, where the gradient of the objective function is:

[0089]

[0090] The Hessian matrix of the objective function is:

[0091]

[0092] The updated result is:

[0093]

[0094] When the number of iterations reaches the preset number of iterations, the iteration is stopped to obtain the final LED positioning result.

[0095] S23 determines the initial filter value, dynamically adjusts the state vector of the LED positioning result, filters the initial filter value and the LED positioning result, and obtains the positioning result of the detection vehicle;

[0096] Compared with the existing UWB and INS fusion positioning, the present invention does not need to install an additional UWB base station, and directly uses the existing LED light source in the warehouse as the positioning signal source, which greatly reduces the installation cost and maintenance cost of the system. At the same time, the anti-interference ability of the visible light signal is stronger than that of the UWB signal, and it can provide more stable positioning performance in complex electromagnetic environments such as dry bulk warehouses. Therefore, the present invention is easier to promote and apply in dry bulk warehouse environments.

[0097] S3. Positioning based on INS, specifically including the following sub-steps:

[0098] S30. Determine the initial position of the detection vehicle, obtain the linear acceleration and angular velocity of the detection vehicle, perform an integral operation on the initial position, linear acceleration and angular velocity of the detection vehicle, and obtain the current speed and INS positioning result of the detection vehicle;

[0099] S31. Determine the initial filter value, dynamically adjust the state vector of the current speed and INS positioning result, filter the initial filter value, current speed, and INS positioning result, and obtain the positioning result of the detection vehicle.

[0100] As a possible implementation method, S23 and S31 are both implemented based on the Kalman filter algorithm, and the initial filter value is the positioning result of the detected vehicle at the last moment.

[0101] As a possible implementation method, filtering processing includes a prediction process and an update process;

[0102] The prediction process is implemented as follows:

[0103] X K,k-1 =F k,k-1 X k-1 ,

[0104]

[0105] In the formula, k represents the kth moment, Xk-1 is the state vector at time k-1, X k,k-1 is the predicted value of the state vector at time k, F k,k-1 is the state transfer matrix at time k, P k,k-1 represents the prediction of the covariance matrix at time k, Q k-1 represents the process noise covariance matrix at time k-1;

[0106] The update process is implemented as follows:

[0107]

[0108] X k =X k,k-1 +K k (z k -H k X k-1 ),

[0109]

[0110] In the formula, K k represents the Kalman gain, z k represents the measurement vector, H k represents the observation matrix, R k represents the measurement noise covariance matrix, X k is the final updated state vector, P k is the conditional error covariance matrix at time k.

[0111] The present invention introduces a variable state dimensional Kalman filter based on attitude angle, and takes the attitude angle as the decision condition for switching the positioning mode. When the attitude angle is within the threshold range, LED is used for positioning. When the attitude angle exceeds the threshold range, it automatically switches to the INS positioning mode, thereby realizing intelligent switching between LED positioning and INS positioning and ensuring the continuity and robustness of positioning.

[0112] Five different positioning methods including the positioning method of the present invention are used to conduct experimental comparison and evaluation of positioning performance. The five methods are: INS positioning method, LED positioning method, INS positioning method based on Kalman filtering, INS and LED fusion positioning method based on Kalman filtering, and the dry bulk cargo warehouse inspection vehicle positioning method based on LED light source proposed by the present invention. In this experiment, the parameters of the device based on LED light source positioning are set as shown in Table 1:

[0113]

[0114] The parameters of the device based on INS positioning are set as shown in Table 2:

[0115]

[0116]

[0117] The test results are as follows Figure 2 As shown, it can be seen that there is a cumulative error in INS positioning, which still exists even after Kalman filter enhancement. The method proposed in the present invention shows the most accurate positioning performance, which is very consistent with the ideal trajectory. The root mean square error of INS positioning is calculated to be 0.27637, and the root mean square error of applying the Kalman filter to the LED and INS positioning results is 0.29236. In contrast, the scheme proposed in the present invention reduces the root mean square error to 0.03810. Compared with INS positioning, the positioning error is reduced by 86.21%, and compared with the Kalman filter method, the positioning error is reduced by 86.97%.

[0118] In order to further verify the solution proposed by the present invention, this embodiment continues to experiment with square trajectory and linear reciprocating motion. The experimental results are shown in Figure 3 and Figure 4 ,The results confirm that the present invention effectively mitigates the position drift caused by the INS accumulated ,error, and achieves better performance than using INS alone or applying Kalman filter to LED and INS results.

[0119] When the present invention switches modes, the final positioning result of the previous positioning mode is used as the filtering starting value of the current positioning mode. According to different positioning modes, the state vector dimension is adaptively adjusted, and the entire positioning process is filtered to realize LED and INS fusion positioning. The INS positioning error is corrected by using the LED positioning information, which effectively alleviates the problem of cumulative error in INS positioning and significantly improves the positioning accuracy. Even in the case of long-term operation, a high positioning accuracy can be maintained to adapt to different terrain conditions, such as ramps and obstacles in dry bulk warehouses.

[0120] In a second aspect, the present invention provides a dry bulk cargo warehouse inspection vehicle positioning system based on LED light sources, see Figure 5 , including: an inertial navigation module 1, an LED positioning module 2 and a variable state dimension Kalman filter module 3 based on attitude angle;

[0121] The inertial navigation module 1 is installed on the inspection vehicle, and the specific installation position is not limited. It is preferably installed at the center of gravity of the inspection vehicle to obtain the linear acceleration and angular velocity of the inspection vehicle, and perform integral operations on the initial position, linear acceleration and angular velocity of the inspection vehicle to obtain the current speed, attitude angle and INS positioning result of the inspection vehicle;

[0122] See also Figure 5, as a possible implementation, the inertial navigation module 1 includes a measurement unit 10 and an INS positioning unit 11;

[0123] The measuring unit 10 includes an accelerometer 100 and a gyroscope 101. The accelerometer 100 is used to obtain the linear acceleration of the detection vehicle, and the gyroscope 101 is used to obtain the angular velocity of the detection vehicle.

[0124] The INS positioning unit 11 is used to perform integration operations on the initial position, linear acceleration and angular velocity of the detection vehicle to obtain the current velocity, INS positioning result and attitude angle of the detection vehicle.

[0125] The LED positioning module 2 is used to demodulate the received optical signal, determine the target LED light source that transmits the optical signal based on the demodulated optical signal frequency, calculate the distance between the detection vehicle and the target LED light source, and obtain the LED positioning result of the detection vehicle;

[0126] See also Figure 5 As a possible implementation, the LED positioning module 2 includes N LED light sources 20, a communication unit 21 and an LED positioning unit 22, where N is greater than or equal to 3;

[0127] The communication unit 21 includes a modulator 210, a photodiode 211 and a demodulator 212. The modulator 210 is used to identify each LED light source using light signals of different frequencies; the photodiode 211 is used to receive light signals; the demodulator 212 is used to demodulate the received light signals and determine the target LED light source that transmits the light signal based on the frequency of the demodulated light signals;

[0128] The LED positioning unit 22 is used to calculate the distance between the detection vehicle and the target LED light source to obtain the LED positioning result of the detection vehicle.

[0129] As a possible implementation, the photodiode 211 is installed on the inspection vehicle at a position directly above the inertial navigation module 1 to ensure the continuity of the positioning result based on LED light source positioning or INS positioning.

[0130] The variable state dimension Kalman filter module 3 based on the attitude angle is used to switch between LED light source positioning and INS positioning, determine the initial filtering value and filter the initial filtering value and the result output by the positioning method to obtain the positioning result of the detection vehicle.

[0131] See also Figure 5As a possible implementation method, the variable state dimensional Kalman filter module 3 based on the attitude angle includes a mode switching unit 30 and a data filtering unit 31. The mode switching unit 30 automatically switches between LED light source-based positioning and INS-based positioning according to the judgment result of whether the attitude angle is within the threshold range; the data filtering unit 31 is used to determine the positioning result of the detection vehicle at the last moment as the initial filtering value when the positioning method is switched, and filter the result output by the positioning method to obtain the positioning result of the detection vehicle.

[0132] In a third aspect, the present invention provides a terminal including a processor and a communication interface coupled to the processor, wherein the processor is used to run a computer program or instruction to implement the dry bulk cargo warehouse inspection vehicle positioning method based on an LED light source provided in the first aspect.

[0133] Although the present invention is described herein in conjunction with various embodiments, in the process of implementing the claimed invention, those skilled in the art may understand and implement other variations of the disclosed embodiments by viewing the drawings, the disclosure, and the drawings, etc. In the specification, the word "comprising" does not exclude other components or steps, and "one" or "an" does not exclude multiple situations. A single processor or other unit can implement several functions listed in the specification. Certain measures are recorded in different embodiments, but this does not mean that these measures cannot be combined to produce good results.

[0134] Although the present invention has been described in conjunction with specific features and embodiments thereof, it is apparent that various modifications and combinations may be made thereto without departing from the spirit and scope of the present invention. Accordingly, this specification and the accompanying drawings are merely exemplary illustrations of the present invention and are deemed to cover any and all modifications, variations, combinations or equivalents within the scope of the present invention. Obviously, those skilled in the art may make various modifications and variations to the present invention without departing from the spirit and scope of the present invention. Thus, the present invention is intended to include such modifications and variations if they fall within the scope of the present invention and its equivalents.

Claims

1. A method for positioning a dry bulk cargo warehouse inspection vehicle based on an LED light source, characterized in that: The dry bulk cargo bin is provided with a plurality of LED light sources; The threshold range of the attitude angle of the detection vehicle is pre-configured; the positioning method positions the detection vehicle in real time, and the positioning method includes: S1. Obtain the attitude angle of the detection vehicle and determine whether the attitude angle is within the threshold range; if so, execute S2; otherwise, execute S3; S2. Positioning based on LED light source, specifically including the following sub-steps: S20. Using light signals of different frequencies to identify each LED light source; S21 demodulates the optical signal received by the detection vehicle, and determines the target LED light source emitting the optical signal based on the demodulated optical signal frequency; S22. Calculate the distance between the detection vehicle and the target LED light source, and obtain the LED positioning result of the detection vehicle based on the distance; S23 determines the initial filter value, dynamically adjusts the state vector of the LED positioning result, filters the initial filter value and the LED positioning result, and obtains the positioning result of the detection vehicle; S3. Positioning based on INS, specifically including the following sub-steps: S30. Determine the initial position of the detection vehicle, obtain the linear acceleration and angular velocity of the detection vehicle, perform an integral operation on the initial position, linear acceleration and angular velocity of the detection vehicle, and obtain the current speed and INS positioning result of the detection vehicle; S31. Determine an initial filter value, dynamically adjust the state vector of the current speed and the INS positioning result, filter the initial filter value, the current speed, and the INS positioning result, and obtain the positioning result of the detection vehicle.

2. The method for positioning a dry bulk cargo warehouse inspection vehicle based on an LED light source according to claim 1, characterized in that: Both S23 and S31 are implemented based on the Kalman filter algorithm, and the initial filter value is the positioning result of the detected vehicle at the last moment.

3. The method for positioning a dry bulk cargo warehouse inspection vehicle based on an LED light source according to claim 1, characterized in that: The S22 specifically includes: S220. Calculate the distance between the detection vehicle and the target LED light source using the following formula: Where m represents the Lambert radiation order, A represents the equivalent receiving area of ​​the photodiode, φ represents the angle between the incident light and the normal line of the photodiode surface, θ represents the angle of the emitted light from the LED light source, and T s represents the transmittance of the LED light signal at the photodiode, P0 represents the received signal power from the LED light source to the photodiode, and P r It indicates the received power of the photodiode after passing through the optical material; S221. Order The solution process in S220 is transformed into the following objective function: In the formula, S(x,y) represents the position coordinates of the detection vehicle, and N represents the number of LED light sources; S222. Preset the number of iterations, use the quasi-Newton algorithm to solve the gradient and Hessian matrix of the above objective function, and iterate the LED positioning result. When the number of iterations reaches the preset number of iterations, stop the iteration to obtain the final LED positioning result.

4. The method for positioning a dry bulk cargo warehouse inspection vehicle based on an LED light source according to claim 1, characterized in that: The filtering process includes a prediction process and an update process; The prediction process is implemented by the following method: X k,k-1 =F k,k-1 X k-1 , In the formula, k represents the kth moment, X k-1 is the state vector at time k-1, X k,k-1 is the predicted value of the state vector at time k, F k,k-1 is the state transfer matrix at time k, P k,k-1 represents the prediction of the covariance matrix at time k, Q k-1 represents the process noise covariance matrix at time k-1; The updating process is implemented by the following method: X k =X k,k-1 +K k (z k -H k X k-1 ), In the formula, K k represents the Kalman gain, z k represents the measurement vector, H k represents the observation matrix, R k represents the measurement noise covariance matrix, X k is the final updated state vector, P k is the conditional error covariance matrix at time k.

5. A dry bulk cargo warehouse inspection vehicle positioning system based on LED light source, characterized in that: include: Inertial navigation module, LED positioning module and variable state dimension Kalman filter module based on attitude angle; The inertial navigation module is installed on the detection vehicle and is used to obtain the linear acceleration and angular velocity of the detection vehicle, perform integral operations on the initial position of the detection vehicle, the linear acceleration and the angular velocity, and obtain the current speed, attitude angle and INS positioning result of the detection vehicle; The LED positioning module is used to demodulate the received optical signal, determine the target LED light source that transmits the optical signal based on the frequency of the demodulated optical signal, calculate the distance between the detection vehicle and the target LED light source, and obtain the LED positioning result of the detection vehicle; The variable state dimension Kalman filter module based on attitude angle is used to switch the positioning method, determine the initial filtering value and filter the initial filtering value and the result output by the positioning method to obtain the positioning result of the detection vehicle.

6. The dry bulk cargo warehouse inspection vehicle positioning system based on LED light source according to claim 5 is characterized in that: The inertial navigation module includes a measurement unit and an INS positioning unit; The measuring unit includes an accelerometer and a gyroscope, wherein the accelerometer is used to obtain the linear acceleration of the detection vehicle, and the gyroscope is used to obtain the angular velocity of the detection vehicle; The INS positioning unit is used to perform an integration operation on the initial position of the detection vehicle, the linear acceleration and the angular velocity to obtain the current velocity of the detection vehicle, the INS positioning result and the attitude angle.

7. The dry bulk cargo warehouse inspection vehicle positioning system based on LED light source according to claim 5 is characterized in that: The LED positioning module includes N LED light sources, a communication unit and an LED positioning unit, where N is greater than or equal to 3; The communication unit includes a modulator, a photodiode and a demodulator, wherein the modulator is used to identify each LED light source using light signals of different frequencies; the photodiode is used to receive light signals; the demodulator is used to demodulate the received light signals and determine the target LED light source that transmits the light signal based on the frequency of the demodulated light signals; The LED positioning unit is used to calculate the distance between the detection vehicle and the target LED light source to obtain the LED positioning result of the detection vehicle.

8. The dry bulk cargo warehouse inspection vehicle positioning system based on LED light source according to claim 5 is characterized in that: The variable state dimension Kalman filter module based on attitude angle includes a mode switching unit and a data filtering unit; The mode switching unit automatically switches between LED light source-based positioning and INS-based positioning according to a judgment result of whether the attitude angle is within a threshold range; The data filtering unit is used to determine the positioning result of the detection vehicle at the last moment as the initial filtering value when the positioning method is switched, and to filter the result output by the positioning method to obtain the positioning result of the detection vehicle.

9. The dry bulk cargo warehouse inspection vehicle positioning system based on LED light source according to claim 7, characterized in that: The photodiode is installed on the inspection vehicle at a position directly above the inertial navigation module.

10. A terminal, characterized in that: It includes a processor and a communication interface coupled to the processor, and the processor is used to run a computer program or instruction to implement the dry bulk cargo warehouse inspection vehicle positioning method based on an LED light source as described in any one of claims 1 to 4.

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