Laser three-dimensional scanning system and method for real-time monitoring of greenhouse bulk material inventory

Abstract

The invention discloses a laser three-dimensional scanning system and method for real-time monitoring of greenhouse bulk material inventory. The system comprises a laser scanning unit; an environment sensing module; a weighing data acquisition module; a data processing module; a dynamic compensation and calibration module; an inventory analysis module; a feedback control unit; a communication module; volume information of a material pile is directly obtained through a laser scanning technology, the subjectivity of manual checking is overcome, and the system can sense and quantify the influence of environmental interference on a scanning result in real time by integrating various environmental sensors such as vibration, temperature and dust concentration and introducing a dynamic compensation mathematical model, so that the system is more accurate and reliable. And accurate compensation is carried out.

Description

Technical Field

[0001] This invention relates to the field of inventory monitoring technology, and in particular to a laser three-dimensional scanning system and method for real-time monitoring of bulk material inventory in greenhouses. Background Technology

[0002] In the warehousing and management of bulk materials, especially in large agricultural greenhouses, accurate and real-time inventory monitoring is crucial for enterprises' cost control, production planning, and logistics scheduling. To achieve accurate inventory management and production scheduling, it is necessary to efficiently and accurately measure the volume and distribution of bulk materials in the greenhouse. Currently, commonly used inventory monitoring technologies include camera-based inventory monitoring systems, such as the one disclosed in patent application CN109328359A, which uses multiple cameras to capture images of shelves and combines them with depth information to construct a real-scene image. However, this monitoring method is easily affected by factors such as changes in light and shadows when monitoring irregularly shaped bulk material piles with large surface undulations in greenhouses, thus limiting the measurement accuracy. Especially in agricultural greenhouse environments with high dust concentrations, the image quality captured by the cameras will be severely affected, leading to a decrease in the reliability of inventory data. There are also inventory counting methods based on lidar, such as the one in patent application CN115561775A, which uses lidar to scan and obtain point cloud data of the material surface to calculate the volume. However, in the face of the complex dynamic environment inside the greenhouse, such as the continuous vibration caused by the operation of mechanical equipment, the temperature fluctuation caused by the diurnal temperature difference, and the dust and water mist generated by irrigation and fertilization, there is a lack of effective real-time dynamic compensation mechanism. It is difficult to overcome the measurement error caused by environmental disturbances, and it cannot respond and adjust quickly to instantaneous changes in the environment. The system lacks sufficient flexibility and adaptability, making it difficult to guarantee the stability and reliability of long-term monitoring. Summary of the Invention

[0003] The present invention aims to address the shortcomings of the prior art by providing a laser three-dimensional scanning system and method for real-time monitoring of bulk material inventory in greenhouses.

[0004] To achieve the above objectives, the present invention adopts the following technical solution:

[0005] A laser 3D scanning system for real-time monitoring of bulk material inventory in greenhouses includes:

[0006] Laser scanning unit: used to emit laser beams and receive signals reflected from the surface of materials to obtain distance and angle information of materials and acquire point cloud data;

[0007] Environmental sensing module: includes vibration sensor, temperature sensor and dust concentration sensor, used to monitor environmental parameters inside the greenhouse in real time;

[0008] Weighing data acquisition module: used to acquire material weight data from an external weighing system;

[0009] Data processing module: used to stitch, denoise and reconstruct 3D point cloud data to generate a 3D model of the material pile;

[0010] Dynamic compensation and calibration module: Built-in dynamic compensation and calibration algorithm to process point cloud data acquired by laser scanning in real time according to environmental parameters;

[0011] Inventory Analysis Module: Calculates material volume based on a 3D model and combines it with weight data to analyze inventory changes and generate anomaly alerts;

[0012] Feedback control unit: Based on the output results of the dynamic compensation and calibration module and the inventory analysis module, it sends control commands to the laser scanning unit through the control algorithm to automatically adjust the laser scanning parameters and calibration model. The adjusted scanning parameters include scanning speed, angle and frequency.

[0013] Communication module: Used to upload inventory data to a remote server or monitoring terminal;

[0014] Visual monitoring interface: used to display the 3D model, volume data and real-time change trend of materials, and provide a management interface;

[0015] The laser scanning unit emits a laser beam and receives reflected signals according to the preset parameters or the parameters adjusted by the feedback control unit. It converts the received signals into distance and angle data and stores them in the system or transmits them to the dynamic compensation and calibration module.

[0016] The weighing data acquisition module is connected to at least one of a weighbridge system, a belt scale, or a fixed scale inside the warehouse.

[0017] The dynamic compensation and calibration module receives raw data from the laser scanning unit and the environmental sensing module, performs noise reduction and filtering on the laser scanning data to eliminate random errors and noise, and verifies and removes outliers from the environmental parameter data.

[0018] The dynamic compensation and calibration module calculates the impact of environmental parameters on the scanning results based on the environmental parameter database and algorithm, and performs dynamic compensation on the laser scanning data. The dynamic compensation and calibration module performs dynamic compensation on the scanning data using the following formula:

[0019] ,in, These are environmental parameter coefficients. It is a reference temperature point. It is a nonlinear transformation of dust concentration. This represents the interaction between vibration, temperature, and dust concentration. This is the residual term.

[0020] The inventory analysis module is used to calculate the volume difference of materials before and after loading / unloading, and to judge the consistency of loading and unloading by combining the weight difference of vehicles entering and leaving. When the volume difference and weight difference are inconsistent, an alarm is issued.

[0021] The control algorithm of the feedback control unit is a PID control algorithm, and its control signal is... ,in, This is a control signal, i.e., an adjustment command sent to the laser scanning unit; , and These are the proportional, integral, and differential gain coefficients, respectively. This refers to the error signal calculated based on point cloud data quality or environmental interference. The integral of error represents the time from time 0 to the current time. The cumulative error; It is the derivative of the error, reflecting the rate of change of the error over time.

[0022] A laser scanning method for real-time monitoring of bulk material inventory in greenhouses, comprising the following steps:

[0023] Step S1: System Initialization and Data Acquisition

[0024] The laser scanning unit is activated, and according to preset parameters or feedback control commands, a laser beam is emitted towards the bulk material pile in the greenhouse and the reflected signal is received to obtain the distance and angle information of the material and form initial point cloud data.

[0025] The environmental sensing module is activated simultaneously, and the environmental parameters inside the greenhouse are monitored and collected in real time through vibration sensors, temperature sensors and dust sensors;

[0026] The weight data of the material is obtained from an external weighing system through the weighing data acquisition module;

[0027] S2 Step: Data Processing and Dynamic Compensation Calibration

[0028] The point cloud data is stitched together, denoised, and reconstructed in three dimensions to generate a three-dimensional model of the material pile.

[0029] Based on the collected environmental parameters, the impact of environmental parameters on the scanning results is calculated using dynamic compensation and calibration algorithms, and dynamic compensation is performed on the laser scanning data.

[0030] S3 Step: Inventory Analysis and Consistency Judgment

[0031] Based on the compensated 3D model, calculate the inventory volume of the materials; combine the weighing data to calculate the difference in material volume before and after loading / unloading and the difference in vehicle weight entering and leaving, and determine whether the two changes in the same direction; if they do not change, an abnormal alarm will be triggered; if they do change, the inventory data will be updated.

[0032] S4 Step: Feedback Control and Parameter Adjustment

[0033] Based on the results of dynamic compensation and inventory analysis, an air conditioning command is generated through a feedback control unit. The control algorithm employs a PID control algorithm to obtain the control signal. According to the control signal The scanning speed, angle, and frequency of the laser scanning unit are automatically adjusted to optimize the scanning effect;

[0034] S5 Step: Data Upload and Visualization

[0035] The processed inventory data, 3D model and alarm information are uploaded to a remote server or monitoring terminal via the communication module.

[0036] The system displays the material's 3D model, volume data, weight information, and real-time trend in a visual monitoring interface, and provides a human-computer interaction management interface.

[0037] In step S1, the laser scanning unit is mounted on an autonomous mobile robot. The method also includes controlling the autonomous mobile robot to cruise along a preset path inside the greenhouse. During the cruise, the laser scanning unit performs intermittent or continuous scanning and automatically stitches together the point cloud data obtained from multi-station scanning to generate a complete full-field 3D model.

[0038] In step S3, determining whether the directions of change of the two are consistent specifically includes:

[0039] When the signs of the weight difference and volume difference are opposite, it is determined that the changes are consistent;

[0040] When the weight difference and volume difference have the same sign, it is determined that the changes are inconsistent, and an alarm message is immediately issued.

[0041] The visual monitoring interface also provides the following functions: displaying the change curve of historical inventory data and supporting queries by time range; receiving loading / unloading plan information manually entered by the user and comparing it with the results automatically judged by the system; and providing an alarm information management interface for confirming, processing and recording alarm events.

[0042] The beneficial effects of this invention are as follows: This invention directly obtains the volume information of the material pile through laser scanning technology, overcoming the subjectivity of manual inventory. By integrating multiple environmental sensors such as vibration, temperature, and dust concentration, and introducing a dynamic compensation mathematical model, the system can perceive and quantify the impact of environmental interference on the scanning results in real time and perform precise compensation. This allows the invention to maintain high-precision measurement results even under harsh conditions such as temperature fluctuations, mechanical vibration, and dust in greenhouses. By combining laser scanning volume data with weighing data, consistency judgment of loading and unloading can be made, effectively preventing management loopholes and abnormal risks such as omissions, misrecording, theft, and replacement of goods. Attached Figure Description

[0043] Figure 1 This is a framework diagram of the laser scanning system for real-time monitoring of bulk material inventory in greenhouses according to the present invention;

[0044] Figure 2 This is a flowchart of the laser scanning method for real-time monitoring of bulk material inventory in greenhouses according to the present invention.

[0045] The following will describe in detail, with reference to the accompanying drawings, embodiments of the invention. Detailed Implementation

[0046] The present invention will be further described below with reference to the accompanying drawings and embodiments:

[0047] A laser 3D scanning system for real-time monitoring of bulk material inventory in greenhouses includes:

[0048] Laser scanning unit: used to emit laser beams and receive signals reflected from the material surface to obtain distance and angle information of the material and acquire point cloud data; the laser scanning unit adopts RIEGL VZ-400i ground 3D scanner. The laser scanning unit is mounted on a pan-tilt unit driven by a servo motor. The servo motor is a Panasonic MINAS A6 system motor, which is installed on a column in the center of the greenhouse, about 5m above the ground. The viewing angle can cover the entire material pile area. The laser scanning unit is connected to the data processing module via Ethernet.

[0049] Environmental sensing module: Includes vibration sensors, temperature sensors, and dust concentration sensors, used to monitor environmental parameters inside the greenhouse in real time; the vibration sensor is an IMI Sensors 608A11 industrial accelerometer, installed on the gimbal base of the laser scanning unit, used to monitor mechanical vibration; the temperature sensor is a PT100 platinum resistance thermometer, installed next to the laser scanning unit, avoiding direct sunlight; the dust concentration sensor is a Pantene PMS7003 laser dust sensor, installed near the scanning area, used to monitor PM2.5 / PM10 concentration in the air. All sensor data are collected to the data acquisition card via RS-485 bus and uploaded to the data processing module.

[0050] Weighing data acquisition module: Used to acquire material weight data from external weighing systems. A weighbridge is set up at the entrance and exit of the greenhouse. The weighbridge is an SCS-60T digital truck scale. After the vehicle is weighed, the weighing data acquisition module sends the data packet containing the license plate number, time and weight information to the weighing data acquisition interface of this system via PCP / IP protocol.

[0051] Data processing module: used to stitch, denoise and reconstruct 3D data of point cloud data to generate a 3D model of the material pile. An industrial computer is set up in the greenhouse monitoring room. The industrial computer is responsible for running data processing, dynamic compensation, inventory analysis and feedback control algorithms.

[0052] Dynamic compensation and calibration module: Built-in dynamic compensation and calibration algorithm to process point cloud data acquired by laser scanning in real time according to environmental parameters;

[0053] Inventory Analysis Module: Calculates material volume based on a 3D model and combines it with weight data to analyze inventory changes and generate anomaly alerts;

[0054] Feedback control unit: Based on the output results of the dynamic compensation and calibration module and the inventory analysis module, it sends control commands to the laser scanning unit through the control algorithm programmed by Siemens S7-1200 PLC, automatically adjusting the laser scanning parameters and calibration model. The adjusted scanning parameters include scanning speed, angle and frequency.

[0055] Communication module: Used to upload inventory data to a remote server or monitoring terminal;

[0056] Visual monitoring interface: Adopting a B / S architecture, it uses WebGL technology for 3D model rendering. Managers can access it through terminal browsers such as computers and tablets to display the 3D model, volume data and real-time change trends of materials, and provide a management interface.

[0057] The laser scanning unit emits a laser beam and receives reflected signals according to the preset parameters or the parameters adjusted by the feedback control unit. It converts the received signals into distance and angle data and stores them in the system or transmits them to the dynamic compensation and calibration module.

[0058] Example 1

[0059] After the system is powered on, each module initializes sequentially: the laser scanning unit loads default parameters, with a scanning speed of 10Hz, a horizontal angle range of 120°, and a pitch angle range of ±30°; the environmental sensing module begins to collect environmental parameters in real time, with the sampling frequency set to 10Hz; the weighing data acquisition module establishes a connection with the external weighbridge system; and the system enters its normal operating cycle.

[0060] The laser scanning unit emits a 905nm band laser beam according to the set parameters and irradiates the surface of the bulk material.

[0061] The system receives the returned reflected signals, calculates the distance and obtains the angle information, generates raw point cloud data, and transmits it to the dynamic compensation and calibration module; the environmental perception module synchronously transmits the collected environmental parameters to the same module.

[0062] After receiving the raw point cloud data, the dynamic compensation and calibration module processes it in the following order: a) Gaussian filtering is applied to the point cloud data for noise reduction, with a window size of 3×3; b) Environmental parameter data is verified, and obvious outliers are removed. Data compensation is then performed using the dynamic compensation and calibration algorithm, calculated using the following formula. Among them, the environmental parameter coefficients were determined through regression analysis of historical data as follows: =0.12, =-0.05, =0.08, =0.0003, reference temperature point Set to 25℃ Dynamically updated through real-time residual analysis.

[0063] The compensated data is transmitted to the inventory analysis module: the material volume is calculated based on the 3D model, and combined with the weight data from the weighing data acquisition module, the difference in material volume before and after loading / unloading is calculated. Calculate the weight difference between the entry and exit of the same vehicle. ,if A negative value indicates loading, and If the value is positive, it is determined that the change is consistent;

[0064] if A negative value indicates loading, and If the value is also negative, it is determined to be inconsistent, and an alarm message is immediately issued. Simultaneously, the feedback control unit, based on the output of the inventory analysis module and the results of the dynamic compensation and calibration module, uses a PID control algorithm to calculate the control signal. , where proportional gain =2.1, Integral Gain =0.5, differential gain =0.3, error signal Defined as the deviation between a point cloud data quality metric and a target value, such as point cloud density, the feedback control unit will... The data is converted into specific adjustment instructions and sent to the laser scanning unit to modify the scanning parameters in real time, such as adjusting the scanning speed from 10Hz to 12Hz. The final processed data is then uploaded to the cloud server via the communication module. The material's three-dimensional model, volume, weight data, and changing trends are displayed in real time in the form of a heat map on the visual monitoring interface.

[0065] In the inventory analysis module, when there are inconsistencies, the system performs the following actions: issues an audible and visual alarm, marks the abnormal event with a flashing red icon on the visual interface, and waits for managers to conduct further review and processing through the interface.

[0066] The invention has been described above with reference to the accompanying drawings. Obviously, the specific implementation of the invention is not limited to the above-described manner. Any improvements made using the inventive concept and technical solution, or direct application to other situations without modification, are all within the scope of protection of the invention.

Claims

1. A laser three-dimensional scanning system for real-time monitoring of bulk material inventory in greenhouses, characterized in that, include: Laser scanning unit: used to emit laser beams and receive signals reflected from the surface of materials to obtain distance and angle information of materials and acquire point cloud data; Environmental sensing module: includes vibration sensor, temperature sensor and dust concentration sensor, used to monitor environmental parameters inside the greenhouse in real time; Weighing data acquisition module: used to acquire material weight data from an external weighing system; Data processing module: used to stitch, denoise and reconstruct 3D point cloud data to generate a 3D model of the material pile; Dynamic compensation and calibration module: Built-in dynamic compensation and calibration algorithm to process point cloud data acquired by laser scanning in real time according to environmental parameters; Inventory Analysis Module: Calculates material volume based on a 3D model and combines it with weight data to analyze inventory changes and generate anomaly alerts; Feedback control unit: Based on the output results of the dynamic compensation and calibration module and the inventory analysis module, it sends control commands to the laser scanning unit through the control algorithm to automatically adjust the laser scanning parameters and calibration model. The adjusted scanning parameters include scanning speed, angle and frequency. Communication module: Used to upload inventory data to a remote server or monitoring terminal; Visual monitoring interface: used to display the 3D model, volume data and real-time change trend of materials, and provide a management interface; The laser scanning unit emits a laser beam and receives reflected signals according to the preset parameters or the parameters adjusted by the feedback control unit. It converts the received signals into distance and angle data and stores them in the system or transmits them to the dynamic compensation and calibration module.

2. The laser three-dimensional scanning system for real-time monitoring of bulk material inventory in greenhouses according to claim 1, characterized in that, The weighing data acquisition module is connected to at least one of a weighbridge system, a belt scale, or a fixed scale inside the warehouse.

3. The laser three-dimensional scanning system for real-time monitoring of bulk material inventory in greenhouses according to claim 1, characterized in that, The dynamic compensation and calibration module receives raw data from the laser scanning unit and the environmental sensing module, performs noise reduction and filtering on the laser scanning data to eliminate random errors and noise, and verifies and removes outliers from the environmental parameter data.

4. The laser three-dimensional scanning system for real-time monitoring of bulk material inventory in greenhouses according to claim 3, characterized in that, The dynamic compensation and calibration module calculates the impact of environmental parameters on the scanning results based on the environmental parameter database and algorithm, and performs dynamic compensation on the laser scanning data. The dynamic compensation and calibration module performs dynamic compensation on the scanning data using the following formula: ,in, These are environmental parameter coefficients. It is a reference temperature point. It is a nonlinear transformation of dust concentration. This represents the interaction between vibration, temperature, and dust concentration. This is the residual term.

5. A laser three-dimensional scanning system for real-time monitoring of bulk material inventory in greenhouses according to claim 1, characterized in that, The inventory analysis module is used to calculate the volume difference of materials before and after loading / unloading, and to judge the consistency of loading and unloading by combining the weight difference of vehicles entering and leaving. When the volume difference and weight difference are inconsistent, an alarm is issued.

6. The laser three-dimensional scanning system for real-time monitoring of bulk material inventory in greenhouses according to claim 1, characterized in that, The control algorithm of the feedback control unit is a PID control algorithm, and its control signal is... ,in, This is a control signal, i.e., an adjustment command sent to the laser scanning unit; , and These are the proportional, integral, and differential gain coefficients, respectively. This refers to the error signal calculated based on point cloud data quality or environmental interference. The integral of error represents the time from time 0 to the current time. The cumulative error; It is the derivative of the error, reflecting the rate of change of the error over time.

7. A laser scanning method for real-time monitoring of bulk material inventory in greenhouses, utilizing the laser three-dimensional scanning system for real-time monitoring of bulk material inventory in greenhouses as described in claims 2, 4, 5, or 6, characterized in that, The steps are as follows: Step S1: System Initialization and Data Acquisition The laser scanning unit is activated, and according to preset parameters or feedback control commands, a laser beam is emitted towards the bulk material pile in the greenhouse and the reflected signal is received to obtain the distance and angle information of the material and form initial point cloud data. The environmental sensing module is activated simultaneously, and the environmental parameters inside the greenhouse are monitored and collected in real time through vibration sensors, temperature sensors and dust sensors; The weight data of the material is obtained from an external weighing system through the weighing data acquisition module; S2 Step: Data Processing and Dynamic Compensation Calibration The point cloud data is stitched together, denoised, and reconstructed in three dimensions to generate a three-dimensional model of the material pile. Based on the collected environmental parameters, the impact of environmental parameters on the scanning results is calculated using dynamic compensation and calibration algorithms, and dynamic compensation is performed on the laser scanning data. S3 Step: Inventory Analysis and Consistency Judgment Based on the compensated 3D model, the inventory volume of the material is calculated; combined with the weighing data, the difference in material volume before and after loading / unloading and the difference in vehicle weight entering and leaving are calculated to determine whether the two changes in the same direction. If they are inconsistent, an error alarm will be triggered; if they are consistent, the inventory data will be updated. S4 Step: Feedback Control and Parameter Adjustment Based on the results of dynamic compensation and inventory analysis, an air conditioning command is generated through a feedback control unit. The control algorithm employs a PID control algorithm to obtain the control signal. According to the control signal The scanning speed, angle, and frequency of the laser scanning unit are automatically adjusted to optimize the scanning effect; S5 Step: Data Upload and Visualization The processed inventory data, 3D model and alarm information are uploaded to a remote server or monitoring terminal via the communication module. The system displays the material's 3D model, volume data, weight information, and real-time trend in a visual monitoring interface, and provides a human-computer interaction management interface.

8. The laser scanning method for real-time monitoring of bulk material inventory in greenhouses according to claim 7, characterized in that, In step S1, the laser scanning unit is mounted on an autonomous mobile robot. The method also includes controlling the autonomous mobile robot to cruise along a preset path inside the greenhouse. During the cruise, the laser scanning unit performs intermittent or continuous scanning and automatically stitches together the point cloud data obtained from multi-station scanning to generate a complete full-field 3D model.

9. The laser scanning method for real-time monitoring of bulk material inventory in greenhouses according to claim 8, characterized in that, In step S3, determining whether the directions of change of the two are consistent specifically includes: When the signs of the weight difference and volume difference are opposite, it is determined that the changes are consistent; When the weight difference and volume difference have the same sign, it is determined that the changes are inconsistent, and an alarm message is immediately issued.

10. The laser scanning method for real-time monitoring of bulk material inventory in greenhouses according to claim 9, characterized in that, The visual monitoring interface also provides the following functions: displaying the change curve of historical inventory data and supporting queries by time range; receiving loading / unloading plan information manually entered by the user and comparing it with the results automatically judged by the system; and providing an alarm information management interface for confirming, processing and recording alarm events.

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