An indoor test device for simulating crop lodging

Abstract

This invention discloses an indoor experimental device for simulating crop root lodging, relating to the technical field of agricultural engineering. It includes an experimental workbench, an observation system, a visualized root-soil system, a wind load simulation system, and a rainfall simulation system. The observation system and the visualized root-soil system are mounted on the experimental workbench. The observation system can rotate around the visualized root-soil system to observe its deformation and failure process. The wind load simulation system and the rainfall simulation system are located on one side of the experimental workbench. The wind load simulation system can apply a load to the plants in the visualized root-soil system to simulate wind load, and the rainfall simulation system can spray water onto the plants to simulate rainfall. This invention can monitor the root deformation and damage process, the failure process of the transparent soil, the internal displacement field, and the internal strain field without invasiveness, resulting in minimal interference from the external environment and low dispersion of the experimental results.

Description

Technical Field

[0001] This invention relates to the technical field of agricultural engineering, and in particular to an indoor experimental device for simulating crop root lodging. Background Technology

[0002] Crops lodging refers to the phenomenon where upright plants deviate from their natural vertical orientation due to external forces and cannot automatically recover. It is divided into root lodging and stem lodging. In recent years, with significant global climate change, crop lodging has become increasingly frequent, and the economic losses caused by lodging have increased year by year, becoming a serious problem in agricultural production. At present, the mechanical mechanism of crop stem lodging is relatively clear, but the mechanical mechanism of crop root lodging, which involves the deformation and damage of the root-soil system, remains unclear.

[0003] To delve into the mechanical mechanisms of crop lodging, researchers have conducted extensive experimental studies. The most direct method is field trials. However, the occurrence of lodging in field trials depends on specific climatic conditions, such as sufficiently large wind loads and rainfall infiltration, which is not conducive to conducting repeated experiments on crop lodging. To conduct repeated experiments on crop lodging, researchers designed wind turbine devices or static loading devices to simulate wind loads in nature and used artificial construction loads to induce crop lodging, thereby deepening their understanding of the mechanical mechanisms of crop lodging.

[0004] To conduct repeatable experiments on crop lodging, researchers have designed wind turbines or static loading devices to simulate wind loads in nature, artificially inducing lodging to deepen their understanding of the mechanical mechanisms of crop lodging. However, these experimental devices are generally used in the field and cannot directly observe the deformation and interaction between roots and soil during lodging, thus hindering a thorough understanding of the mechanical mechanisms of crop lodging. Furthermore, rainfall infiltration, wind load, and wind-rain coupling are the main factors causing crop lodging, and current field experimental devices cannot specifically address these factors. Summary of the Invention

[0005] The purpose of this invention is to provide an indoor experimental device for simulating crop root lodging, so as to solve the problems existing in the prior art, and to make the deformation displacement process and interaction relationship of roots and soil during the pull-out process of crop root-soil system more intuitive to observe and record, which is convenient for experimental research.

[0006] To achieve the above objectives, the present invention provides the following solution:

[0007] This invention provides an indoor experimental device for simulating crop root lodging, comprising an experimental workbench, an observation system, a visual root-soil system, a wind load simulation system, and a rainfall simulation system. The observation system and the visual root-soil system are arranged on the experimental workbench. The observation system can rotate around the visual root-soil system to observe the deformation and failure process of the root-soil system. The wind load simulation system and the rainfall simulation system are arranged on one side of the experimental workbench. The wind load simulation system can apply a load to the plants in the visual root-soil system to simulate wind load, and the rainfall simulation system can spray water on the plants to simulate rainfall.

[0008] Preferably, the experimental workbench includes a transparent platform plate and lifting support columns, with a lifting support column connected to each of the four corners of the transparent platform plate, and the visualization root-soil system is located in the middle of the transparent platform plate.

[0009] Preferably, the lifting support column includes a screw and a screw sleeve. The screw sleeve is rotatably disposed below the experimental workbench, the screw is fixedly disposed on a base, the screw sleeve is threadedly connected to the screw, and several column feet are evenly distributed below the base.

[0010] Preferably, the transparent platform is made of plexiglass; a universal level is installed at each of the four corners of the top surface of the transparent platform.

[0011] Preferably, the observation system includes a laser emitter, a computer, and an industrial camera. The laser emitter is mounted on the base and located below the visualized root-soil system. The industrial camera is rotatably mounted on the transparent platform plate around the visualized root-soil system. Both the laser emitter and the industrial camera are communicatively connected to the computer.

[0012] Preferably, a circular slide rail is provided on the transparent platform plate, with the center of the visual root-soil system as the center, and the industrial camera is mounted on a slide block that matches the circular slide rail.

[0013] Preferably, the visualized root-soil system includes a transparent sample box, transparent soil, and a plant, wherein the sample box contains the transparent soil and the plant is planted in the transparent soil.

[0014] Preferably, the wind load simulation system includes a force application mechanism and an angle adjustment mechanism. The force application mechanism is movably connected to the angle adjustment mechanism. The angle adjustment mechanism is fixed to the ground or a platform. The force application mechanism is equipped with a force gauge and a displacement gauge. The force application mechanism is used to clamp the stem of the plant.

[0015] Preferably, the force-applying mechanism includes a servo motor, a winch, and a clamp. The servo motor is connected to the winch. The winch's rope passes sequentially over a fixed pulley and a movable pulley and is connected to the clamp. A rope displacement sensor is provided between the winch and the clamp. The clamp is equipped with a force gauge and an inclination sensor. The angle adjustment mechanism includes an inverted bracket, a lead screw, a slider, and a motor. The bracket is set on the ground or a platform and located on one side of the experimental workbench. A lead screw is provided on the bracket, and the slider is sleeved on the lead screw. The motor is connected to one end of the lead screw. The slider is horizontally connected to a movable pulley via a crossbar. A fixed pulley is provided at the lower part of the bracket, and the fixed pulley is located below the movable pulley. A rope displacement sensor is provided on the crossbar. The motor, the servo motor, and the winch are each connected to a PLC programmable controller.

[0016] Preferably, the rainfall simulation system includes a water tank, a water pump, a sprinkler pipe, and a sprinkler head. The water tank is connected to the sprinkler head via the water pump and the sprinkler pipe, and the sprinkler head is located above the plant.

[0017] The present invention achieves the following technical effects compared to the prior art:

[0018] 1. This invention solves the problem that conventional experimental devices cannot directly observe the deformation and displacement process and interrelationship of roots and soil during the pull-out process of crop root-soil systems. It can monitor the deformation and damage process of roots, the failure process of transparent soil, the internal displacement field and the internal strain field without intrusion. The invention uses a visualized root-soil system to plant plants, a wind load simulation system to apply loads to plants to simulate wind loads, and a rainfall simulation system to spray water on plants to simulate rainfall. This makes the experiment less affected by the external environment and the experimental results less discrete.

[0019] 2. The wind load simulation system of the present invention simulates wind load by applying load to the plant. The use of an adjustable ultra-wide clamp effectively avoids stem damage during the test. The coordinated movement of two motors in the force application mechanism and angle adjustment mechanism is controlled by a PLC programmable controller to ensure that the direction of force application is perpendicular to the stem of the plant. The combination of the adjustable ultra-wide clamp and the PLC programmable controller enables a more precise simulation of wind load.

[0020] 3. The rainfall simulation system of the present invention can simulate the change of soil moisture content by spraying water from a sprinkler head set on the top of the device.

[0021] 4. This invention combines the wind load simulation system and the rainfall simulation system in the artificial root lodging system, which can be used to study the mechanical mechanism of crop root lodging under the individual effects of wind load and rainfall infiltration, as well as the coupled effects of wind and rain load.

[0022] 5. This invention uses a root-transparent soil system as the test material and simulates wind and rain loads indoors, which makes the test less affected by the external environment and the test results less discrete. Attached Figure Description

[0023] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0024] Figure 1 This is a schematic diagram of the indoor test device for simulating crop root lodging according to the present invention. Figure 1 ;

[0025] Figure 2 This is a schematic diagram of the indoor test device for simulating crop root lodging according to the present invention. Figure 2 ;

[0026] Figure 3 This is a schematic diagram of the structure of the experimental workbench in this invention. Figure 1 ;

[0027] Figure 4 This is a schematic diagram of the structure of the experimental workbench in this invention. Figure 2 ;

[0028] The components are as follows: 1-Water tank, 2-Water pump, 3-Spray pipe, 4-Bracket, 5-Screw, 6-Column foot, 7-Base, 8a / 8b-Rope displacement sensor, 9-Servo motor, 10-Winder, 11-Rope, 12-Signal converter, 13-Computer, 14-Screw sleeve, 15-Laser emitter, 16-Fixed pulley, 17-Lead screw, 18-Moving pulley, 19-Slider, 20-Universal level, 21-Circular slide rail, 22-Slide seat, 23-Industrial camera, 24-Transparent soil, 25-Plant, 26-Force gauge, 27-Clamp, 28-Transparent platform plate, 29-Limit bolt, 30-Spray head, 31-Sample box, 32-PLC programmable controller, 33-Wire rope, 34-Tilt sensor, 35-Crossbar, 36-Motor. Detailed Implementation

[0029] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. 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 are within the scope of protection of the present invention.

[0030] The purpose of this invention is to provide an indoor experimental device for simulating crop root lodging, so as to solve the problems existing in the prior art, and to make the deformation displacement process and interaction relationship of roots and soil during the pull-out process of crop root-soil system more intuitive to observe and record, which is convenient for experimental research.

[0031] To make the above-mentioned objects, features and advantages of the present invention more apparent and understandable, the present invention will be further described in detail below with reference to the accompanying drawings and specific embodiments.

[0032] like Figures 1 to 4 As shown: This embodiment provides an indoor experimental device for simulating crop root lodging, including an experimental workbench, an observation system, a visual root-soil system, a wind load simulation system, and a rainfall simulation system. The observation system and the visual root-soil system are set on the experimental workbench. The observation system can rotate around the visual root-soil system to observe the deformation and failure process of the root-soil system. The wind load simulation system and the rainfall simulation system are set on one side of the experimental workbench. The wind load simulation system can apply a load to the plant 25 in the visual root-soil system to simulate wind load, and the rainfall simulation system can spray water on the plant 25 to simulate rainfall.

[0033] The experimental workbench includes a transparent platform plate 28 and lifting support columns. A lifting support column is connected to each of the four corners of the transparent platform plate 28. The visualization root-soil system is located in the center of the transparent platform plate. Each lifting support column includes a screw rod 5 and a threaded sleeve 14. The threaded sleeve 14 is rotatably mounted below the experimental workbench, while the screw rod 5 is fixedly mounted on a base 7. The threaded sleeve 14 is threadedly connected to the screw rod 5, enabling the lifting and adjustment of the transparent platform plate 28. Several column feet 6 are evenly distributed below the base 7 to reduce the impact of unevenness of the base 7 on the stability of the experimental workbench. The transparent platform plate 28 is made of plexiglass. A universal level 20 is installed at each of the four corners of the top surface of the transparent platform plate 28 for easy adjustment of its level.

[0034] The observation system includes a laser emitter 15, a computer 13, and an industrial camera 23. The laser emitter 15 is mounted on the base 7 and located below the visualized root-soil system, providing a laser light source for the industrial camera 23. The industrial camera 23 rotates around the visualized root-soil system and is mounted on a transparent platform plate 28 to record particle images, i.e., obtaining the desired particle images through PIV technology. Both the laser emitter 15 and the industrial camera 23 are communicatively connected to the computer 13. A circular slide rail 21 is provided on the transparent platform plate 28, with the center of the visualized root-soil system as its center. The industrial camera 23 is mounted on a sliding block 22, which matches the circular slide rail 21. The position of the industrial camera 23 can be changed by manually moving the sliding block 22 on the slide rail, thereby ensuring that the industrial camera 23 does not vibrate significantly and can monitor the changes throughout the entire lodging process from all angles.

[0035] The visualized root-soil system includes a transparent sample box 31, transparent soil 24, and a plant 25. The sample box 31 contains the transparent soil 24, and the plant 25 is planted within the transparent soil 24. In this embodiment, the bottom plate of the sample box 31 is locked to the transparent platform plate 28 by limiting bolts 29 for easy positioning.

[0036] The wind load simulation system includes a force application mechanism and an angle adjustment mechanism. The force application mechanism is movably connected to the angle adjustment mechanism. The angle adjustment mechanism is fixed to the ground or a platform. The force application mechanism is equipped with a force gauge 26 and a displacement gauge 8. The force application mechanism is used to clamp the stem of the plant 25. The force-applying mechanism includes a servo motor 9, a winch 10, and a clamp 27. The servo motor 9 is connected to the winch 10. The rope 11 of the winch 10 passes sequentially over a fixed pulley 16 and a movable pulley 18 and connects to the clamp 27. The clamp 27 is used to lock the plant 25 to the rope 11. The rope 11 is preferably a steel wire rope. A rope displacement sensor 8a is installed between the winch 10 and the clamp 27. The rope displacement sensor 8a is used to measure the displacement of the plant 25's root system and the loading time during the lodging process. A force gauge 26 and an inclination sensor 34 are installed on the clamp 27. The force gauge 26 is used to measure the magnitude of the pulling force applied during the lodging process, and the inclination sensor 34 is used to measure the inclination angle of the plant 25 during the lodging process. The motor 36, servo motor 9, and winch 10 are each connected to a PLC programmable controller 32. By adjusting the speed of the servo motor 9, the winch 10 is driven to change the magnitude and rate of the pulling force of the rope 11, thereby applying wind load. The angle adjustment mechanism includes an inverted support 4, a lead screw 17, a slider 19, and a motor 36. The support 4 is set on the ground or platform and located on one side of the experimental workbench. The lead screw 17 is set on the support 4, and the slider 19 is sleeved on the lead screw 17. The motor 36 is connected to one end of the lead screw 17. The slider 19 is horizontally connected to a movable pulley 18 through a crossbar 35. A fixed pulley 16 is set at the lower part of the support 4. The fixed pulley 16 is located below the movable pulley 18. A rope displacement sensor 8b is set on the crossbar 35. The movable pulley 18 changes the position of the slider 19 on the lead screw 17 through the motor 36 to achieve vertical displacement (which can be measured by the rope displacement sensor 8b), thereby changing the angle between the pulling force and the plant 25 during the lodging process.

[0037] The rainfall simulation system includes a water tank 1, a water pump 2, a sprinkler pipe 3, and sprinkler heads 30. The water tank 1 is connected to the sprinkler heads 30 via the water pump 2 and the sprinkler pipe 3. The sprinkler heads 30 are located above the plants 25. The water pump 2, PLC programmable controller 32, industrial camera 23, force gauge 26, and rope displacement sensor 8 are all connected to the computer 13 via a signal converter 12 for data and image acquisition, facilitating automated control.

[0038] The specific usage method of the indoor experimental device for simulating crop root lodging in this embodiment includes the following steps:

[0039] Step 1: Prepare transparent soil 24: Mix n-dodecane and white oil in a specific ratio to obtain a pore solution. Adjust the ratio of n-dodecane and white oil until the refractive index of the pore solution is the same as that of the fused silica sand particles. Then, stir and mix the selected fused silica sand particles and the pore solution with the matching refractive index at a certain temperature. After thorough stirring, use a vacuum pump to evacuate the mixture until it becomes transparent. Let it stand for 12 hours. To prepare root-soil systems for crops at different growth stages, plant the crop plants 25 in transparent soil 24 and wait for them to grow.

[0040] Step 2: Assemble the transparent platform plate 28. Install the industrial camera 23 on the circular slide rail 21 of the transparent platform plate 28, and install the laser emitter 15 and computer 13. Place the root-soil system of crops at different growth stages in the sample box 31. Cut off the upper structure of the crop plant 25, leaving only the root-soil system and a section of stem adjacent to the root. Fix the sample box 31 to the transparent platform plate 28 with several limiting bolts 29. Assemble the prepared root-transparent soil system with the wind load simulation system. Connect the stem of the plant 25 to the rope 11 with the clamp 27. Adjust the clamping position of the clamp 27 to adjust the point of application of the external load. Connect the rope 11 through two pulleys to the force gauge 26. Connect the force gauge 26 to the computer 13. Connect the rope 11 to the winch 10. Next, connect the pull head of the wire rope 33 in the pull rope displacement sensor 8a to the end of the clamp 27 along the rope 11, ensuring that the wire rope 33 and the outlet of the pull rope displacement sensor 8a are concentric; connect the pull head of the wire rope 33 in the pull rope displacement sensor 8b to the crossbar 35, ensuring that the wire rope 33 and the outlet of the pull rope displacement sensor 8b are concentric; connect the servo motor 9 and the motor 36 on the lead screw 17 to the PLC programmable controller 33, and connect the two pull rope displacement sensors 8a and 8b to the computer 13 for communication, and connect the servo motor 9 to the winch 10; finally, under the modulation of the PLC programmable controller 32, they move in tandem to achieve the pulling force during the lodging process being perpendicular to the stem of the plant 25; assemble the rainfall simulation system and adjust the position of the sprinkler head 30 according to the experimental design requirements.

[0041] Step 3: According to the requirements of the experimental design, adjust the position of the slider 19 on the lead screw 17 in the wind load simulation system, that is, adjust the angle of action of the external load; adjust the tension of the rope 11 by the winch 10 until the reading of the pull force in the force gauge 26 is exactly zero, or the reading on the rope displacement sensor 8 no longer changes.

[0042] The control logic of the PLC programmable controller 32 is as follows: based on the initial position and displacement information of the stem of the plant 25, the clamp 27, and the slider 19, the displacement value of the slider 19 that ensures the pulling force remains perpendicular to the stem of the plant 25 is calculated through geometric relationships.

[0043]

[0044] In the formula: L1 is the distance between clamp 27 and movable pulley 18 before the test, which is measured by rope displacement sensor 8b before the test; α is the angle between plant 25 and the vertical direction during the test, which can be measured by tilt sensor 34; ΔL is the displacement change value of plant 25 root system during the test, which can be obtained by measuring two instantaneous displacements by rope displacement sensor 8a and then subtracting them.

[0045] Step 4: Turn on the laser emitter 15 and industrial camera 23. Connect the force gauge 26 and industrial camera 23 to the signal converter 12, and then connect them and the PLC programmable controller 33 to the computer 13. Aim the laser emitter 15 at the sample and the industrial camera 23 at the front of the sample box 31 to take pictures and record. Adjust the position of the laser emitter 15 to form a speckle field in the transparent soil 24. Use the industrial camera 23 to continuously record the speckle field of the transparent soil and the deformation of the plant roots, and then calculate the strain of the transparent soil 24 and the roots of the plant 25.

[0046] Step 5: Start and coordinate the wind load simulation system and rainfall simulation system. Adjust the speed of the servo motor 9 through the PLC programmable controller 33 so that the winch 10 can drive the rope 11 to move downward at a certain speed. At this time, according to the displacement change fed back by the rope displacement sensor 8a, the motor 36 is adjusted synchronously, which drives the slider 19 to move on the lead screw 17, thereby causing the crossbar 35 to drive the movable pulley 18 to move together. When the displacement reading on the rope displacement sensor 8a reaches the set value, the loading stops, or when the pulling force value on the force gauge 26 reaches the set value, the loading stops.

[0047] Step Six: After the experiment, use computer 13 to save the experimental images and data, turn off the rainfall simulation system, laser emitter 15, and industrial camera 23, adjust the winch 10 with servo motor 9 to pull rope 11 back to its original position, loosen clamp 27, disconnect the rope heads of the two rope displacement sensors 8, and slowly pull them back to the outlet, close the lock between sample box 31 and transparent platform plate 28, and move sample box 31 away from the experimental workbench; use computer 13 to process the data, comprehensively analyze and obtain the image evolution law and data of the experimental process, and analyze the relationship between displacement deformation and pull-out force between roots and soil during the deformation and failure of the crop root-soil system.

[0048] This specification uses specific examples to illustrate the principles and implementation methods of the present invention. The descriptions of the above embodiments are only for the purpose of helping to understand the method and core ideas of the present invention. Furthermore, those skilled in the art will recognize that, based on the ideas of the present invention, there will be changes in the specific implementation methods and application scope. Therefore, the content of this specification should not be construed as a limitation of the present invention.

Claims

1. An indoor experimental device for simulating crop root lodging, characterized in that: The device includes an experimental workbench, an observation system, a visual root-soil system, a wind load simulation system, and a rainfall simulation system. The observation system and the visual root-soil system are installed on the experimental workbench. The observation system can rotate around the visual root-soil system to observe the deformation and failure process of the root-soil system. The wind load simulation system and the rainfall simulation system are located on one side of the experimental workbench. The wind load simulation system can apply a load to the plants in the visual root-soil system to simulate wind load, and the rainfall simulation system can spray water on the plants to simulate rainfall. The experimental workbench includes a transparent platform plate and a lifting support column. The lifting support column includes a screw and a screw sleeve. The screw sleeve is rotatably disposed below the experimental workbench. The screw is fixedly disposed on a base. The screw sleeve is threadedly connected to the screw. Several column feet are evenly distributed below the base. The observation system includes a laser emitter, a computer, and an industrial camera. The laser emitter is disposed on the base and located below the visualized root-soil system. The industrial camera is rotatably disposed on the transparent platform plate around the visualized root-soil system. Both the laser emitter and the industrial camera are communicatively connected to the computer. The visualized root-soil system includes a transparent sample box, transparent soil, and a plant. The sample box contains the transparent soil, and the plant is planted in the transparent soil. The wind load simulation system includes a force application mechanism and an angle adjustment mechanism. The force application mechanism is movably connected to the angle adjustment mechanism, which is fixed to the ground or a platform. The force application mechanism is equipped with a force gauge and a rope displacement sensor. The force application mechanism is used to clamp the stem of the plant. The force application mechanism includes a servo motor, a winch, and a clamp. The servo motor is connected to the winch. The winch's rope passes sequentially over a fixed pulley and a movable pulley and connects to the clamp. A rope displacement sensor is provided between the winch and the clamp. The fixture is equipped with a force gauge and an inclination sensor. The angle adjustment mechanism includes a support, a lead screw, a slider, and a motor. The support is located on the ground or a platform and is situated on one side of the experimental workbench. The lead screw is mounted on the support, and the slider is fitted onto the lead screw. The motor is connected to one end of the lead screw. The slider is horizontally connected to a movable pulley via a crossbar. A fixed pulley is located at the lower part of the support, below the movable pulley. A rope displacement sensor is mounted on the crossbar.

2. The indoor test device for simulating crop root lodging according to claim 1, characterized in that: A lifting support column is connected to each of the four corners of the transparent platform panel, and the visual root-soil system is located in the middle of the transparent platform panel.

3. The indoor test device for simulating crop root lodging according to claim 2, characterized in that: The transparent platform is made of plexiglass; a universal level is installed at each of the four corners of the top surface of the transparent platform.

4. The indoor test device for simulating crop root lodging according to claim 1, characterized in that: A circular slide rail is provided on the transparent platform plate, with the center of the visualized root-soil system as the center. The industrial camera is mounted on a sliding block, which matches the circular slide rail.

5. The indoor test device for simulating crop root lodging according to claim 1, characterized in that: The motor, the servo motor, and the winch are each connected to a PLC programmable controller.

6. The indoor test device for simulating crop root lodging according to claim 1, characterized in that: The rainfall simulation system includes a water tank, a water pump, a sprinkler pipe, and sprinkler heads. The water tank is connected to the sprinkler heads via the water pump and the sprinkler pipe, and the sprinkler heads are located above the plants.

Images