Attitude compensation monitoring and control method and system for unmanned aerial vehicle carrying solution residual amount

Abstract

The present application belongs to the technical field of unmanned aerial vehicle and liquid level monitoring, and relates to a method and system for attitude compensation monitoring and control of solution residual amount carried by an unmanned aerial vehicle. The present application obtains real-time attitude data of the unmanned aerial vehicle, wherein the attitude data includes pitch angle and roll angle; obtains liquid level height data collected by liquid level sensors deployed at at least two different positions inside a solution pod; calculates a corrected real solution residual amount by an attitude compensation algorithm according to the attitude data and the liquid level height data; compares the real solution residual amount with a preset high liquid level threshold and / or low liquid level threshold, and performs corresponding safety control actions according to the comparison result; and realizes accurate monitoring and intelligent safety control of the solution residual amount carried by the unmanned aerial vehicle, without manual intervention, to perform protection actions such as overloading prohibition of take-off and low liquid level automatic return, thereby greatly reducing the risk of safety accidents caused by solution residual amount misjudgment of the unmanned aerial vehicle.

Description

Technical Field

[0001] This invention belongs to the fields of unmanned aerial vehicle (UAV) technology and liquid level monitoring technology, and relates to a method and system for attitude compensation monitoring and control of the remaining solution volume carried by an UAV. Background Technology

[0002] With the rapid development of drone technology, drones carrying liquid pods have been widely used in cleaning operations, agricultural plant protection, and firefighting. During operation, these drones need to monitor the remaining solution level in the pod in real time to prevent overloading that could lead to insufficient power or a crash, and to prevent damage to the cleaning motor or water pump from running dry under low liquid levels.

[0003] In existing technologies, the monitoring scheme for the remaining solution carried by UAVs typically adopts the following approach: a single liquid level sensor (such as a float switch, ultrasonic level gauge, capacitive level sensor, etc.) is installed in the pod, and the liquid level value of the sensor is directly read as the remaining solution volume; at the same time, fixed high liquid level alarm thresholds and low liquid level alarm thresholds are set, and an alarm is issued when the liquid level exceeds or falls below the corresponding threshold.

[0004] However, the aforementioned existing technologies have the following obvious shortcomings in practical applications: First, during flight, the drone will exhibit pitch and roll attitudes, causing the liquid level in the pod to tilt accordingly. A single liquid level sensor can only measure the local liquid level at its installation location and cannot reflect the true remaining solution volume in the entire pod. At larger tilt angles, the measurement error of a single-point liquid level sensor is significant, resulting in severe distortion.

[0005] Secondly, due to measurement distortion, operators may mistakenly believe that the remaining liquid is low when the liquid level is high and continue to add liquid, causing the actual takeoff weight to exceed the drone's maximum payload capacity and posing an overload flight risk. Conversely, when the liquid level is low, operators may mistakenly believe that the remaining liquid is sufficient, causing the cleaning motor or water pump to run continuously without liquid, resulting in equipment damage or even burnout.

[0006] Third, the existing solution only provides alarm prompts and is not linked with the drone's flight control system, so it cannot automatically perform protective actions (such as prohibiting takeoff, automatically shutting down the motors, or forcing a return to home), resulting in insufficient safety response capabilities. Summary of the Invention

[0007] The purpose of this invention is to provide a method and system for attitude compensation monitoring and control of the remaining solution volume on a UAV, so as to solve the technical problems of measurement distortion caused by the influence of flight attitude in monitoring the remaining solution volume on a UAV, as well as the risk of high liquid level overload takeoff and low liquid level equipment idling damage caused by measurement inaccuracy.

[0008] To achieve the above objectives, the present invention employs the following technical solution: Secondly, this invention discloses a method for attitude compensation monitoring and control of the remaining solution on a UAV, comprising the following steps: Acquire real-time attitude data of the UAV, including pitch angle and roll angle; Acquire liquid level data from liquid level sensors deployed at at least two different locations inside the solution pod; Based on the attitude data and the liquid level height data, the corrected actual solution balance is calculated using an attitude compensation algorithm. The actual remaining solution level is compared with a preset high liquid level threshold and / or low liquid level threshold, and corresponding safety control actions are performed based on the comparison results. When the comparison result triggers multiple safety control actions based on high liquid level threshold and low liquid level threshold simultaneously, they are executed in a preset safety priority order, wherein the priority order is: safety control actions related to high liquid level overload take precedence over safety control actions related to low liquid level.

[0009] Furthermore, the attitude compensation algorithm includes the following method one and / or method two: Method 1: Based on the installation coordinates of each liquid level sensor in the pod and the tilt angle of the UAV, establish the liquid surface plane equation; based on the installation coordinates of each liquid level sensor and the tilt angle of the UAV, calculate the equivalent liquid level height value of each sensor measured on the preset reference horizontal plane in the pod; perform weighted average or least squares fitting on the multiple projected liquid level values ​​to obtain the corrected true solution balance. Method 2: Establish a correction coefficient table for different tilt angles and tilt directions in advance; obtain the corresponding correction coefficient by looking up the table based on the current attitude data; multiply the average value of the measured liquid level height of each liquid level sensor by the correction coefficient to obtain the corrected actual solution balance.

[0010] Furthermore, the high liquid level threshold is the maximum takeoff solution volume. When the corrected actual solution volume exceeds the high liquid level threshold, the safety control actions performed include: prohibiting the drone from taking off, limiting the maximum takeoff weight of the drone, and / or issuing an overload alarm.

[0011] Furthermore, the low liquid level threshold is the minimum amount of solution to be returned. When the corrected actual solution level is lower than or equal to the low liquid level threshold, the safety control actions performed include: turning off or reducing the output power of the cleaning motor or water pump, and / or triggering the drone to automatically return to home or hover and wait for instructions.

[0012] Furthermore, the low liquid level threshold is dynamically adjusted based on one or more of the following factors, through a preset functional relationship or a lookup table: the drone's current remaining battery power, the distance between the drone's current location and the return point, the current task priority, and the solution consumption rate.

[0013] Furthermore, it also includes sending the corrected actual solution balance to the ground monitoring platform in real time, and displaying it visually on the ground monitoring platform. The visualization includes numerical display, progress bar display, and / or a three-dimensional tilted liquid level dynamic diagram drawn according to the real-time attitude of the UAV.

[0014] Furthermore, the liquid level sensor includes, but is not limited to, one or more of the following: float-type liquid level sensor, capacitive liquid level sensor, pressure-type liquid level sensor, ultrasonic liquid level sensor, and photoelectric liquid level sensor.

[0015] Furthermore, the method also includes a sensor redundancy verification step: When the deviation between the data from a certain liquid level sensor and the data from other sensors exceeds a preset threshold, the sensor is determined to be a faulty sensor. In the attitude compensation algorithm, the data from the faulty sensor is removed, and only the data from the remaining normal sensors are used for calculation.

[0016] Furthermore, when real-time attitude data of the UAV cannot be obtained, the current tilt angle and tilt direction of the UAV are inferred by the measured liquid level height difference between multiple liquid level sensors. The inferred attitude data is then processed by low-pass filtering or moving average, and the processed attitude data is used as the current attitude data to perform attitude compensation calculation.

[0017] Secondly, the present invention also discloses an attitude compensation monitoring and control system for the remaining solution on a UAV, comprising: The attitude acquisition module is used to acquire real-time attitude data of the UAV, including tilt angle and tilt direction. The liquid level acquisition module includes liquid level sensors deployed at at least two different locations inside the solution pod for acquiring liquid level height data at each location; An airborne computer is connected to the attitude acquisition module and the liquid level acquisition module respectively, and is used to perform the following operations: based on the attitude data and liquid level height data, a fitting algorithm based on the liquid surface plane equation or a lookup algorithm based on a pre-stored correction coefficient table is used to calculate the corrected actual solution balance. A safety control module, connected to the onboard computer, is used to compare the actual remaining solution volume with a preset high liquid level threshold and / or low liquid level threshold, and to execute corresponding safety control actions based on the comparison results. The communication module is used to send the corrected actual solution balance to the ground monitoring platform in real time.

[0018] Compared with the prior art, the present invention has the following beneficial effects: This invention acquires real-time attitude data from a UAV and liquid level height data collected by level sensors deployed at at least two different locations inside the solution pod. Based on the attitude and liquid level height data, an attitude compensation algorithm is used to calculate the corrected actual solution balance. Finally, the actual solution balance is compared with preset high and / or low liquid level thresholds, and corresponding safety control actions are executed. This solves the core technical problem of measurement distortion by single-point level sensors caused by UAV flight tilt in existing technologies. Specifically, by fusing attitude data and multi-point liquid level data and using an attitude compensation algorithm to correct the measured values, measurement errors are reduced. Simultaneously, by comparing the corrected actual solution balance with dual thresholds and executing safety control actions, dual protection against high liquid level overload takeoff and low liquid level equipment idling is achieved, significantly improving the safety and reliability of UAV-borne solution operations.

[0019] This invention's system acquires real-time attitude data of the UAV through an attitude acquisition module, and collects liquid level height data at each location using liquid level sensors deployed at at least two different positions inside the solution pod within the liquid level acquisition module. An onboard computer calculates the corrected actual solution balance based on the attitude and liquid level height data using an attitude compensation algorithm. A safety control module compares the actual solution balance with preset high and / or low liquid level thresholds and executes corresponding safety control actions. The corrected actual solution balance is then transmitted to a ground monitoring platform in real time via a communication module. These modules work together to achieve accurate monitoring and intelligent safety control of the UAV's load-bearing solution balance. Compared to existing single-point liquid level monitoring schemes, this system significantly improves measurement accuracy under tilt conditions and possesses automatic safety response capabilities. It can execute protective actions such as overload takeoff prohibition and automatic return to base at low liquid levels without manual intervention, greatly reducing the risk of safety accidents caused by misjudgment of the UAV's load-bearing solution balance. Attached Figure Description

[0020] Figure 1 This is a flowchart of the method of the present invention; Figure 2 This is a system module diagram of the present invention. Detailed Implementation

[0021] To enable those skilled in the art to better understand the present invention, the technical solutions of the present invention will be clearly and completely described below with reference to the accompanying drawings of the embodiments of the present invention. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort should fall within the scope of protection of the present invention.

[0022] It should be noted that the terms "first," "second," etc., in the specification and accompanying drawings of this invention are used to distinguish similar objects and are not necessarily used to describe a specific order or sequence. It should be understood that such data can be interchanged where appropriate so that the embodiments of the invention described herein can be implemented in orders other than those illustrated or described herein. Furthermore, the terms "comprising" and "having," and any variations thereof, are intended to cover non-exclusive inclusion; for example, a process, method, system, product, or apparatus that comprises a series of steps or units is not necessarily limited to those steps or units explicitly listed, but may include other steps or units not explicitly listed or inherent to such processes, methods, products, or apparatus.

[0023] The present invention will now be described in further detail with reference to the accompanying drawings: Example 1: See Figure 1 This embodiment provides an attitude compensation monitoring and control method for the remaining solution on a drone, applied to a scenario where a hexacopter drone is cleaning the exterior wall of a high-rise building. The drone carries a solution pod containing cleaning fluid, and a spray pump connected to a cleaning motor is installed at the bottom of the pod. The method includes the following steps: S1, acquire real-time attitude data of the UAV, including pitch angle and roll angle; S2, acquire liquid level height data collected by liquid level sensors deployed at at least two different locations inside the solution pod; S3, Based on the attitude data and the liquid level height data, the corrected actual solution balance is calculated using an attitude compensation algorithm; In a preferred embodiment of the present invention, the attitude compensation algorithm includes the following method one and / or method two: Method 1: Based on the installation coordinates of each liquid level sensor in the pod and the tilt angle of the UAV, establish the liquid surface plane equation; based on the installation coordinates of each liquid level sensor and the tilt angle of the UAV, calculate the equivalent liquid level height value of each sensor measured on the preset reference horizontal plane in the pod; perform weighted average or least squares fitting on the multiple projected liquid level values ​​to obtain the corrected true solution balance. Method 2: Establish a correction coefficient table for different tilt angles and tilt directions in advance; obtain the corresponding correction coefficient by looking up the table based on the current attitude data; multiply the average value of the measured liquid level height of each liquid level sensor by the correction coefficient to obtain the corrected actual solution balance.

[0024] Among them, the geometric projection method establishes the liquid surface plane equation based on the installation coordinates of each sensor and the tilt angle of the UAV. The corrected actual solution margin is obtained through projection and weighted averaging or least squares fitting. This method is theoretically more accurate, adaptable to various irregular pod shapes and arbitrary tilt angles, and has a wide range of applications. The lookup table method pre-establishes a table of correction coefficients for different tilt angles and directions. In actual flight, the correction coefficients are quickly obtained by looking up the table. It has low computational load, strong real-time performance, and is particularly suitable for embedded platforms with limited computing resources. Both methods can be flexibly selected or combined according to the actual application scenario, providing users with diverse technical implementation paths.

[0025] S4, compare the actual remaining solution volume with the preset high liquid level threshold and / or low liquid level threshold, and execute the corresponding safety control action according to the comparison result; When the comparison result triggers multiple safety control actions based on high liquid level threshold and low liquid level threshold simultaneously, they are executed in a preset safety priority order, wherein the priority order is: safety control actions related to high liquid level overload take precedence over safety control actions related to low liquid level.

[0026] In a preferred embodiment of the present invention, the high liquid level threshold is the maximum takeoff solution volume. When the corrected actual solution volume exceeds the high liquid level threshold, the safety control actions performed include: prohibiting the drone from taking off, limiting the maximum takeoff weight of the drone, and / or issuing an overload alarm.

[0027] In existing technologies, single-point sensors may misread the actual overloaded high liquid level as a normal liquid level when the drone is tilted. Operators may unknowingly launch an overloaded drone, leading to insufficient power, reduced maneuverability, or even a crash. This invention makes judgments based on a corrected actual margin, ensuring the accuracy of overload assessment. Simultaneously, automatically executed actions such as prohibiting takeoff or limiting takeoff weight require no operator response, avoiding safety risks caused by human error.

[0028] In a preferred embodiment of the present invention, the low liquid level threshold is the minimum amount of solution to be returned. When the corrected actual solution level is lower than or equal to the low liquid level threshold, the safety control actions performed include: shutting down or reducing the output power of the cleaning motor or water pump, and / or triggering an automatic return-to-home or hovering command for the drone. The present invention makes judgments based on the corrected actual solution level, ensuring timely execution of protective actions when the actual solution level reaches the low liquid level threshold; automatically shutting down or reducing motor power prevents equipment from being damaged by idling, and the automatic return-to-home or hovering command further ensures the safe recovery of the drone.

[0029] In a preferred embodiment of the present invention, the low liquid level threshold is dynamically adjusted based on one or more of the following factors, through a preset functional relationship or a lookup table: the current remaining battery power of the drone, the distance between the drone's current position and the return point, the current task priority, and the solution consumption rate.

[0030] In a preferred embodiment of the present invention, the corrected actual solution balance is sent to a ground monitoring platform in real time and displayed visually on the ground monitoring platform. The visualization includes numerical display, progress bar display, and / or a three-dimensional tilted liquid level dynamic diagram drawn according to the real-time attitude of the UAV.

[0031] In a preferred embodiment of the present invention, the liquid level sensor includes, but is not limited to, one or more of the following: float-type liquid level sensor, capacitive liquid level sensor, pressure-type liquid level sensor, ultrasonic liquid level sensor, and photoelectric liquid level sensor.

[0032] In a preferred embodiment of the present invention, the method further includes a sensor redundancy verification step: When the deviation between the data from a certain liquid level sensor and the data from other sensors exceeds a preset threshold, the sensor is determined to be a faulty sensor. In the attitude compensation algorithm, the data from the faulty sensor is removed, and only the data from the remaining normal sensors are used for calculation.

[0033] In actual UAV operations, liquid level sensors may malfunction due to solution corrosion, mechanical vibration, or blockage by foreign objects. In existing single-point sensor solutions, the entire monitoring system fails once the sensor fails. This invention, through multi-point sensor deployment and redundancy verification mechanisms, can automatically identify and isolate faulty sensors, utilizing the remaining normal sensors to continue attitude compensation calculations. This ensures the system continues to function normally even with the failure of one or more sensors, significantly improving system robustness and mission completion rate.

[0034] In a preferred embodiment of the present invention, when real-time attitude data of the UAV cannot be obtained, the current tilt angle and tilt direction of the UAV are inferred by the measured liquid level height difference between multiple liquid level sensors, and the inferred attitude data is processed by low-pass filtering or moving average. The processed attitude data is then used as the current attitude data to perform attitude compensation calculation.

[0035] This invention utilizes the height difference between multiple liquid level sensors to inversely calculate the attitude of a UAV, enabling the system to perform attitude compensation monitoring even in the absence of a dedicated attitude sensor or when the attitude sensor fails. This technical solution reduces the system's dependence on hardware, expands the scope of application of this invention, and is particularly suitable for low-cost UAVs or emergency operation modes after attitude sensor failure.

[0036] See Figure 2 The present invention also discloses an attitude compensation monitoring and control system for the remaining solution on a UAV, comprising: The attitude acquisition module is used to acquire real-time attitude data of the UAV, including tilt angle and tilt direction. The liquid level acquisition module includes liquid level sensors deployed at at least two different locations inside the solution pod for acquiring liquid level height data at each location; An airborne computer is connected to the attitude acquisition module and the liquid level acquisition module respectively, and is used to perform the following operations: based on the attitude data and liquid level height data, a fitting algorithm based on the liquid surface plane equation or a lookup algorithm based on a pre-stored correction coefficient table is used to calculate the corrected actual solution balance. A safety control module, connected to the onboard computer, is used to compare the actual remaining solution volume with a preset high liquid level threshold and / or low liquid level threshold, and to execute corresponding safety control actions based on the comparison results. The communication module is used to send the corrected actual solution balance to the ground monitoring platform in real time.

[0037] The various modules of this invention work together to achieve accurate monitoring and intelligent safety control of the remaining solution on the drone. Compared with the single-point liquid level monitoring scheme in the prior art, this system significantly improves the measurement accuracy under tilt conditions and has automatic safety response capabilities. It can perform protective actions such as overload prohibition of takeoff and automatic return to base when the liquid level is low without manual intervention, which greatly reduces the risk of safety accidents caused by misjudgment of the remaining solution on the drone.

[0038] Example 2: See Figure 1This embodiment provides an attitude compensation monitoring and control method for the remaining solution load on a drone, applied to a scenario where a hexacopter drone is cleaning the exterior wall of a high-rise building. A solution pod is mounted beneath the drone, containing cleaning fluid. A spray pump connected to a cleaning motor is installed at the bottom of the pod. The maximum takeoff weight of the drone is determined based on the drone model, and the empty weight of the pod is known; therefore, the maximum permissible solution load can be calculated in advance. The pod is rectangular in shape and has a rated volume. The method of this invention includes the following steps: S1. Acquire real-time attitude data of the drone, including pitch and roll angles. Specifically, attitude data is acquired in real time via the drone's onboard inertial measurement unit (IMU). When the drone is horizontally positioned, both pitch and roll angles are zero; during the cleaning operation, the drone needs to adjust its attitude to align the nozzle with the wall, at which point the pitch and roll angles vary within a certain range.

[0039] S2, acquire liquid level data collected by liquid level sensors deployed at at least two different locations inside the solution pod. In this embodiment, a capacitive liquid level sensor is installed at each of the four corners of the pod's bottom, for a total of four sensors, labeled P1 (front left), P2 (front right), P3 (rear left), and P4 (rear right). The installation coordinates of each sensor (with the center of the pod's bottom as the origin) are known. Each sensor collects liquid level data at a set sampling frequency and transmits it to the onboard computer via a bus.

[0040] S3, Based on the attitude data and the liquid level height data, the corrected actual solution balance is calculated using an attitude compensation algorithm.

[0041] In a preferred embodiment of the present invention, the attitude compensation algorithm includes the following method one and / or method two: Method 1 (Geometric Projection Method): Based on the installation coordinates of each liquid level sensor within the pod and the tilt angle of the UAV, a liquid surface plane equation is established. Based on the installation coordinates of each liquid level sensor and the tilt angle of the UAV, the equivalent liquid level height value measured by each sensor on a preset reference horizontal plane within the pod is calculated. A weighted average or least-squares fitting is performed on the multiple projected liquid level values ​​to obtain the corrected actual solution balance. Specifically, in this embodiment, the reference horizontal plane is selected as the horizontal plane where the center point of the pod bottom is located. The projection calculation uses the tangent value of the sensor coordinates and the tilt angle. When the calculated projection value is negative, it indicates that there is actually no solution at that location, and the value is zero. The final corrected actual solution balance is the statistical average of the projected values ​​of each sensor multiplied by the bottom area of ​​the pod.

[0042] Method 2 (Table Lookup Method): A correction coefficient table for different tilt angles and tilt directions is pre-established; the corresponding correction coefficient is obtained by looking up the table based on the current attitude data; the average value of the measured liquid level height from each liquid level sensor is multiplied by the correction coefficient to obtain the corrected actual solution balance. Specifically, in this embodiment, the liquid surface distribution under different combinations of tilt angles and tilt directions is simulated in advance using simulation software, and the corresponding correction coefficients are calculated and stored in the onboard computer to form a correction coefficient table. During actual flight, the system interpolates the table based on the current attitude angle to obtain the accurate correction coefficient.

[0043] Among them, the geometric projection method establishes the liquid surface plane equation based on the installation coordinates of each sensor and the tilt angle of the UAV. The corrected actual solution balance is obtained through projection and weighted averaging or least squares fitting. This method is theoretically more accurate, adaptable to various irregular pod shapes and arbitrary tilt angles, and has a wide range of applications. The lookup table method pre-establishes a table of correction coefficients for different tilt angles and directions. In actual flight, the correction coefficients are quickly obtained by looking up the table. It has low computational load and strong real-time performance, making it particularly suitable for embedded platforms with limited computing resources. The two methods can be flexibly selected or combined according to the actual application scenario, providing users with diverse technical implementation paths. In this embodiment, the system defaults to using the geometric projection method to obtain the highest accuracy. When the onboard computer load is high, it automatically switches to the lookup table method to ensure real-time performance.

[0044] S4. The actual remaining solution volume is compared with the preset high liquid level threshold and / or low liquid level threshold, and the corresponding safety control action is executed according to the comparison result.

[0045] Specifically, when the comparison result simultaneously triggers multiple safety control actions based on both high and low liquid level thresholds, they are executed according to a preset safety priority order. The priority order is: safety control actions related to high liquid level overload take precedence over safety control actions related to low liquid level. For example, when a drone simultaneously experiences a conflicting state of high liquid level overload and low liquid level warning (such as data anomalies caused by sensor malfunction), the system prioritizes executing the high liquid level protection action because overload poses a more direct and serious threat to flight safety.

[0046] In a preferred embodiment of the present invention, the high liquid level threshold is the maximum takeoff solution volume. In this embodiment, this threshold is pre-calculated and determined based on the maximum takeoff weight of the UAV and the empty weight of the pod. When the corrected actual solution remaining volume exceeds the high liquid level threshold, the safety control actions performed include: prohibiting the UAV from taking off, limiting the maximum takeoff weight of the UAV, and / or issuing an overload alarm. Specifically, prohibiting the UAV from taking off is achieved by the flight control system rejecting the motor unlock command; limiting the maximum takeoff weight is achieved by limiting the thrust output curve; and the overload alarm is achieved through a pop-up window and voice broadcast on the ground station.

[0047] In existing technologies, single-point sensors may misread the actual overloaded high liquid level as a normal liquid level when the drone is tilted. Operators may unknowingly launch an overloaded drone, leading to insufficient power, reduced maneuverability, or even a crash. This invention makes judgments based on a corrected actual margin, ensuring the accuracy of overload assessment. Simultaneously, automatically executed actions such as prohibiting takeoff or limiting takeoff weight require no operator response, avoiding safety risks caused by human error.

[0048] In a preferred embodiment of the present invention, the low liquid level threshold is the minimum return solution volume. In this embodiment, this threshold is predetermined based on the minimum operating liquid level of the spray pump and the margin required for safe return. When the corrected actual solution margin is lower than or equal to the low liquid level threshold, the safety control actions performed include: shutting down or reducing the output power of the cleaning motor or water pump, and / or triggering an automatic return or hovering command for the UAV. Specifically, when the margin drops to the low liquid level threshold, the system first reduces the spray pump speed to a lower level and simultaneously issues a "low solution margin, return recommended" prompt; when the margin further drops to an even lower safety threshold, the system forcibly shuts down the spray pump and sends a return command to the flight control system, and the UAV automatically adjusts its attitude to return to the take-off and landing point horizontally. The present invention makes judgments based on the corrected actual margin to ensure that protective actions are executed in a timely manner when the actual margin reaches the low liquid level threshold; automatically shutting down or reducing the motor power can prevent equipment from being damaged by idling, and the automatic return or hovering command further ensures the safe recovery of the UAV.

[0049] In a preferred embodiment of the present invention, the low liquid level threshold is dynamically adjusted based on one or more of the following factors, using a preset functional relationship or a lookup table: the drone's current remaining battery power, the distance between the drone's current location and the return point, the current task priority, and the solution consumption rate. In this embodiment, the dynamic adjustment function comprehensively considers factors such as remaining battery power, return distance, and task priority. For example, when the remaining battery power is low or the return distance is long, the system automatically raises the low liquid level threshold to trigger the return trip earlier, avoiding a forced landing due to insufficient battery power; when performing high-priority tasks, the system can appropriately lower the threshold to extend the operation time.

[0050] In a preferred embodiment of the invention, the corrected actual solution balance is transmitted to a ground monitoring platform in real time and displayed visually on the platform. The visualization includes numerical display, progress bar display, and / or a three-dimensional tilted liquid level dynamic graph plotted based on the real-time attitude of the UAV. Specifically, the ground monitoring platform operates on a portable ground station. The numerical display area shows the solution balance in the format of "current balance / total capacity"; the progress bar uses multi-color partitioning, with different colors representing different safety levels; the three-dimensional tilted liquid level dynamic graph dynamically adjusts the tilt angle and direction of the liquid surface based on the real-time attitude data of the UAV, allowing the operator to intuitively perceive the actual distribution of liquid within the pod.

[0051] In a preferred embodiment of the present invention, the liquid level sensor includes, but is not limited to, one or more of the following: float-type liquid level sensor, capacitive liquid level sensor, pressure-type liquid level sensor, ultrasonic liquid level sensor, and photoelectric liquid level sensor. This embodiment uses a capacitive liquid level sensor, which has the advantages of fast response speed, no moving mechanical parts, high reliability, and compatibility with various solution types. In alternative solutions, a pressure-type sensor can be used for high-viscosity solutions, and an ultrasonic non-contact sensor can be used for solutions with high foam content.

[0052] In a preferred embodiment of the present invention, the method further includes a sensor redundancy verification step: When the deviation of the data from a certain liquid level sensor from the data from other sensors exceeds a preset threshold, the sensor is determined to be a faulty sensor. In this embodiment, the preset threshold is set using a relative deviation method. The system calculates the median or average value of the readings of each sensor in real time. If the absolute value of the deviation between the reading of a certain sensor and the median exceeds a preset proportion, and this state continues for more than a certain period of time (i.e., multiple consecutive sampling periods), the sensor is determined to be a faulty sensor.

[0053] In the attitude compensation algorithm, data from the faulty sensor is discarded, and only data from the remaining normal sensors is used for calculation. For example, if a sensor malfunctions due to solution corrosion, and its reading remains fixed at a certain abnormal value while the readings of other sensors change normally, the system automatically detects that the sensor's deviation exceeds a threshold, marks it as "failed," and discards it. The attitude compensation algorithm then switches to using the remaining normal sensors for calculation. Although the measurement accuracy decreases slightly at this point, the system can still function normally.

[0054] In actual UAV operations, liquid level sensors may malfunction due to solution corrosion, mechanical vibration, or blockage by foreign objects. In existing single-point sensor solutions, the entire monitoring system fails once the sensor fails. This invention, through multi-point sensor deployment and redundancy verification mechanisms, can automatically identify and isolate faulty sensors, utilizing the remaining normal sensors to continue attitude compensation calculations. This ensures the system continues to function normally even with the failure of one or more sensors, significantly improving system robustness and mission completion rate.

[0055] In a preferred embodiment of the present invention, when real-time attitude data of the UAV cannot be obtained, the current tilt angle and tilt direction of the UAV are inferred from the measured liquid level height difference between multiple liquid level sensors. The inferred attitude data is then subjected to low-pass filtering or moving average processing, and the processed attitude data is used as the current attitude data for attitude compensation calculation. In this embodiment, when the IMU malfunctions or communication is interrupted, the system automatically switches to attitude inference mode. Inference uses the liquid level height difference between the left and right sensors and the known distance between the sensors to calculate the tilt angle. For example, when the liquid level of the left sensor is higher than that of the right sensor, it can be inferred that the UAV is tilted to the right. To prevent liquid surface fluctuations from causing attitude jitter during inference, the system performs moving average filtering on the inference results, and the filtered attitude data is used for subsequent geometric projection compensation calculations.

[0056] This invention utilizes the height difference between multiple liquid level sensors to inversely calculate the attitude of a UAV, enabling the system to perform attitude compensation monitoring even in the absence of a dedicated attitude sensor or when the attitude sensor fails. This technical solution reduces the system's dependence on hardware, expands the scope of application of this invention, and is particularly suitable for low-cost UAVs or emergency operation modes after attitude sensor failure.

[0057] The above content is only for illustrating the technical concept of the present invention and should not be construed as limiting the scope of protection of the present invention. Any modifications made to the technical solution based on the technical concept proposed in this invention shall fall within the scope of protection of this invention.

Claims

1. A method for attitude compensation monitoring and control of the remaining solution on a UAV, characterized in that, Includes the following steps: Acquire real-time attitude data of the UAV, including pitch angle and roll angle; Acquire liquid level data from liquid level sensors deployed at at least two different locations inside the solution pod; Based on the attitude data and the liquid level height data, the corrected actual solution balance is calculated using an attitude compensation algorithm. The actual remaining solution level is compared with a preset high liquid level threshold and / or low liquid level threshold, and corresponding safety control actions are performed based on the comparison results. When the comparison result triggers multiple safety control actions based on high liquid level threshold and low liquid level threshold simultaneously, they are executed in a preset safety priority order, wherein the priority order is: safety control actions related to high liquid level overload take precedence over safety control actions related to low liquid level.

2. The attitude compensation monitoring and control method for the remaining solution volume of a UAV according to claim 1, characterized in that, The attitude compensation algorithm includes the following methods one and / or two: Method 1: Based on the installation coordinates of each liquid level sensor in the pod and the tilt angle of the UAV, establish the liquid surface plane equation; based on the installation coordinates of each liquid level sensor and the tilt angle of the UAV, calculate the equivalent liquid level height value of each sensor measured on the preset reference horizontal plane in the pod; perform weighted average or least squares fitting on the multiple projected liquid level values ​​to obtain the corrected true solution balance. Method 2: Establish a correction coefficient table for different tilt angles and tilt directions in advance; obtain the corresponding correction coefficient by looking up the table based on the current attitude data; multiply the average value of the measured liquid level height of each liquid level sensor by the correction coefficient to obtain the corrected actual solution balance.

3. The attitude compensation monitoring and control method for the remaining solution volume of a UAV according to claim 1, characterized in that, The high liquid level threshold is the maximum takeoff solution volume. When the corrected actual solution volume exceeds the high liquid level threshold, the safety control actions performed include: prohibiting the drone from taking off, limiting the maximum takeoff weight of the drone, and / or issuing an overload alarm.

4. The attitude compensation monitoring and control method for the remaining solution volume of a UAV according to claim 1, characterized in that, The low liquid level threshold is the minimum amount of solution to be returned. When the corrected actual solution level is lower than or equal to the low liquid level threshold, the safety control actions performed include: turning off or reducing the output power of the cleaning motor or water pump, and / or triggering the drone to automatically return to home or hover and wait for instructions.

5. The attitude compensation monitoring and control method for the remaining solution volume of a UAV according to claim 4, characterized in that, The low liquid level threshold is dynamically adjusted based on one or more of the following factors, through a preset functional relationship or a lookup table: the drone's current remaining battery power, the distance between the drone's current location and the return point, the current task priority, and the solution consumption rate.

6. The method for attitude compensation monitoring and control of unmanned aerial vehicle (UAV) payload solution balance according to claim 1, characterized in that, It also includes sending the corrected actual solution balance to a ground monitoring platform in real time and displaying it visually on the ground monitoring platform. The visualization includes numerical display, progress bar display and / or a three-dimensional tilted liquid level dynamic diagram drawn according to the real-time attitude of the UAV.

7. The attitude compensation monitoring and control method for the remaining solution volume of a UAV according to claim 1, characterized in that, The liquid level sensor includes, but is not limited to, one or more of the following: float-type liquid level sensor, capacitive liquid level sensor, pressure-type liquid level sensor, ultrasonic liquid level sensor, and photoelectric liquid level sensor.

8. The method for attitude compensation monitoring and control of unmanned aerial vehicle (UAV) payload solution balance according to claim 1, characterized in that, The method also includes a sensor redundancy verification step: When the deviation between the data from a certain liquid level sensor and the data from other sensors exceeds a preset threshold, the sensor is determined to be a faulty sensor. In the attitude compensation algorithm, the data from the faulty sensor is removed, and only the data from the remaining normal sensors are used for calculation.

9. The method for attitude compensation monitoring and control of unmanned aerial vehicle (UAV) payload solution balance according to claim 1, characterized in that, When real-time attitude data of the UAV cannot be obtained, the current tilt angle and tilt direction of the UAV are inferred by the measured liquid level height difference between multiple liquid level sensors. The inferred attitude data is then processed by low-pass filtering or moving average, and the processed attitude data is used as the current attitude data to perform attitude compensation calculation.

10. An attitude compensation monitoring and control system for the remaining solution on a UAV, characterized in that, include: The attitude acquisition module is used to acquire real-time attitude data of the UAV, including tilt angle and tilt direction. The liquid level acquisition module includes liquid level sensors deployed at at least two different locations inside the solution pod for acquiring liquid level height data at each location; The airborne computer is used to calculate the corrected actual solution balance based on attitude data and liquid level height data, using either a fitting algorithm based on the liquid surface plane equation or a lookup algorithm based on a pre-stored correction coefficient table. A safety control module, connected to the onboard computer, is used to compare the actual remaining solution volume with a preset high liquid level threshold and / or low liquid level threshold, and to execute corresponding safety control actions based on the comparison results. The communication module is used to send the corrected actual solution balance to the ground monitoring platform in real time.

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