A root crop harvester feed rate detection system and method

Abstract

The present application provides a rhizome crop harvester feeding amount detection system and method, the detection method first measures the material thickness at the front end of the elevator screen, the torque of the transmission shaft and the movement speed of the elevator screen, and transmits the measurement results to the vehicle-mounted computer, the vehicle-mounted computer processes the data of the material thickness at both ends of the elevator screen, the torque of the transmission shaft and the movement speed of the elevator screen, and obtains the current feeding amount of the rhizome crop harvester. Through the collection of the torque of the transmission shaft below the elevator screen, the change of the material feeding amount can be indirectly detected, so that the real-time detection and subsequent control of the material feeding amount during the harvesting process are realized, and the harvesting quality is ensured.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of crop harvesting of intelligent agricultural equipment, in particular to a root and stem crop harvester feeding amount detection system and method. BACKGROUND

[0002] Feeding amount is an important parameter affecting the performance of root and stem crop harvesting operation. When the feeding amount is too small, it will lead to insufficient machine load and reduced operation efficiency. When the feeding amount is too high, it will overload the machine and cause blockage, and even lead to mechanical failure. Therefore, it is of great significance to accurately detect the real-time operation feeding amount of the harvester. At present, there are two main methods for detecting the feeding amount of the harvester in China: one is to detect the related transmission shaft torque or power to represent the feeding amount, and the other is to use the pressure on the bridge bottom plate to represent the feeding amount. These parameters have been proven to have high correlation with the feeding amount, and combined with the related shaft speed, they can effectively reflect the feeding amount information. However, the current detection methods mainly target the feeding amount detection of grain crops, and the existing feeding amount detection technology cannot be applied to root and stem crops due to their different planting environments and growth characteristics. Therefore, for the existing root and stem crop harvesters, how to quickly, conveniently and accurately obtain the feeding amount information of the crops is a key link to improve the working efficiency and ensure the working quality of the harvesting equipment.

[0003] For monitoring the feeding amount of root and stem crop harvesters, a peanut harvester feeding amount monitoring method and monitoring system are disclosed in a Chinese patent with publication number CN107660370A. The monitoring method provided by the patent measures the rotational speed and torque of the fruit picking roller, the transverse displacement of the harvester clamping chain, and the driving speed, and uses a mathematical model to deduce the current feeding amount value of the peanut harvester. Since the measured parameters are more, the uncertainty of the field conditions in the application process will introduce more errors, which will affect the accuracy of the monitored feeding amount.

[0004] According to the problems existing in the existing root and stem crop feeding amount monitoring method, the present application comprehensively considers the detection real-time, detection accuracy and installation convenience, and proposes a root and stem crop harvester feeding amount detection system and method based on the driving shaft torque of the elevator screen. SUMMARY

[0005] In order to solve the problems in the prior art, the present application provides a rhizome crop harvester feeding amount detection system and method, which obtains the corresponding relationship between the feeding amount and the torque of the transmission shaft according to the shape and thickness of the material on the lifting screen and the stress characteristics of the material itself, indirectly detects the change of the material feeding amount by collecting the torque of the transmission shaft below the lifting screen, and realizes the real-time detection and subsequent control of the material feeding amount during the harvesting process, thereby ensuring the harvesting quality.

[0006] In order to achieve the above-mentioned purpose, the present application adopts the following specific scheme:

[0007] A rhizome crop harvester feeding amount detection method is used for the real-time detection of the feeding amount of a rhizome crop harvester, and the lifting screen in the conveying mechanism of the rhizome crop harvester is used for material conveying under the action of the transmission shaft arranged at the front and rear ends of the lifting screen.

[0008] S1, measure the thickness of the material at the two ends of the lifting screen, obtain the thickness of the material at the front end of the lifting screen through the laser distance sensor installed at the front end of the lifting screen, obtain the thickness of the material at the rear end of the lifting screen through the laser distance sensor installed at the rear end of the lifting screen, and transmit the thickness information of the material to the vehicle-mounted computer;

[0009] S2, measure the torque of the transmission shaft, obtain the torque of the transmission shaft through the torque sensor installed on the end face of the front transmission shaft and / or the rear transmission shaft, and transmit the torque information of the transmission shaft to the vehicle-mounted computer;

[0010] S3, obtain the movement speed of the lifting screen, obtain the rotation speed of the transmission shaft through the rotation speed sensor installed on the front transmission shaft and / or the rear transmission shaft, transmit the rotation speed information of the transmission shaft to the vehicle-mounted computer, and the vehicle-mounted computer can calculate the movement speed of the lifting screen according to the rotation speed of the transmission shaft;

[0011] S4, obtain the feeding amount value, the vehicle-mounted computer processes the data of the thickness of the material at the two ends of the lifting screen, the torque of the transmission shaft and the movement speed information of the lifting screen, and obtains the current feeding amount of the rhizome crop harvester;

[0012] In step S4, the calculation formula of the feeding amount is:

[0013] ,

[0014] Wherein, Q is the feeding amount, v0 is the movement speed of the lifting screen, h2 is the thickness of the material at the front end of the lifting screen, M is the torque of the transmission shaft, l is the length of the lifting screen, b is the width of the lifting screen, a is the inclination angle of the lifting screen, r is the radius of the transmission shaft, and μ is the friction coefficient between the material and the lifting screen. ρ is the material filling factor, S is the disturbance amount, g is the gravitational acceleration, and ρ is the material density.

[0015] Furthermore, in step S3, the formula for calculating the speed of the lifting screen is:

[0016] ,

[0017] Where v0 is the speed of the lifting screen, n is the rotational speed of the drive shaft, and r is the radius of the drive shaft.

[0018] On the other hand, the present invention provides a feeding amount detection system for a root and tuber crop harvester, used for real-time detection of the feeding amount of a root and tuber crop harvester, comprising:

[0019] A vehicle-mounted computer;

[0020] Two laser rangefinders are installed at the front and rear ends of the lifting screen, respectively. The laser rangefinder installed at the front end of the lifting screen obtains the material thickness at the front end of the lifting screen, and the laser rangefinder installed at the rear end of the lifting screen obtains the material thickness at the rear end of the lifting screen, and transmits the thickness information to the on-board computer.

[0021] At least one torque sensor is mounted on the end face of the front drive shaft and / or the rear drive shaft to measure the torque of the drive shaft and transmit the torque information of the drive shaft to the on-board computer.

[0022] At least one speed sensor, mounted on the front drive shaft and / or rear drive shaft, is used to measure the speed of the drive shaft and transmit the speed information of the drive shaft to the on-board computer.

[0023] Furthermore, the speed sensor is an inductive speed sensor.

[0024] Furthermore, the torque sensor is a disc-type torque sensor.

[0025] Beneficial effects:

[0026] 1) The detection system in this invention is quick and easy to install and can realize real-time detection of the feeding amount. Compared with existing methods, the detection of the feeding amount is more accurate.

[0027] 2) Since the feed rate has variable characteristics, this invention uses transmission shaft torque measurement to characterize the feed rate, which has the characteristics of good real-time performance and high detection accuracy. Furthermore, it is more convenient to install the sensor on the transmission shaft and has higher stability. Attached Figure Description

[0028] Figure 1 This is a schematic diagram of the working principle of the conveying mechanism in a harvester for root and tuber crops.

[0029] Figure 2 This is a force analysis diagram of the material on the lifting screen.

[0030] Figure 3 This is a flowchart of the feeding amount detection method in this invention.

[0031] The markings in the diagram are: 1. Excavating shovel, 2. Lifting screen, 3. Triangular wheel, 4. Drive shaft, 5. Torque sensor, 6. Material, 7. Screened material, 8. Storage box, 9. Speed ​​sensor, 10. Laser rangefinder. Detailed Implementation

[0032] The technical solution of the present invention will be clearly and completely described below with reference to specific embodiments. 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 protection scope of the present invention.

[0033] First, it should be noted that the feeding amount detection system and method for root and tuber crop harvesters provided by the present invention are for root and tuber crop harvesters with the following characteristics: the conveying mechanism of the root and tuber crop harvester includes a lifting screen for lifting materials, a triangular wheel for vibrating the lifting screen up and down, a first drive mechanism for driving the lifting screen to move, and a second drive mechanism for driving the triangular wheel to rotate at a uniform speed. The first drive mechanism includes a front drive shaft located at the front end of the lifting screen and a rear drive shaft located at the rear end of the lifting screen.

[0034] Please refer to Figure 3 , Figure 3 This is a flowchart of the feeding amount detection method of the present invention. The present invention provides a feeding amount detection method for root and tuber crop harvesters based on the torque of the lifting screen drive shaft, used for real-time detection of the feeding amount in root and tuber crop harvesters. The feeding amount detection method mainly includes the following steps:

[0035] S1. Measure the material thickness at both ends of the lifting screen. Obtain the material thickness at the front end of the lifting screen through a laser rangefinder installed at the front end of the lifting screen, and obtain the material thickness at the rear end of the lifting screen through a laser rangefinder installed at the rear end of the lifting screen. Then transmit the material thickness information to the on-board computer.

[0036] S2. Measure the torque of the drive shaft by acquiring the torque of the drive shaft through a torque sensor installed on the end face of the front drive shaft and / or the rear drive shaft; and transmit the torque information of the drive shaft to the on-board computer.

[0037] S3. Obtain the movement speed of the lifting screen. The rotation speed of the drive shaft is obtained by a speed sensor installed on the front drive shaft and / or the rear drive shaft. The rotation speed information of the drive shaft is transmitted to the on-board computer. The on-board computer can calculate the movement speed of the lifting screen based on the rotation speed of the drive shaft.

[0038] S4. Obtain the feeding amount value. The on-board computer processes the data of the material thickness at both ends of the lifting screen, the torque of the drive shaft, and the movement speed of the lifting screen to obtain the current feeding amount of the root and tuber crop harvester.

[0039] In step S4, the formula for calculating the feeding amount is:

[0040] (1)

[0041] Where Q is the feed rate, v0 is the speed of the lifting screen, h2 is the material thickness at the front end of the lifting screen, M is the torque of the drive shaft, l is the length of the lifting screen, b is the width of the lifting screen, α is the inclination angle of the lifting screen, r is the radius of the drive shaft, and μ is the coefficient of friction between the material and the lifting screen. is the material filling factor, and S is the disturbance amount.

[0042] The formula for calculating the speed of the lifting screen in step S3 is as follows:

[0043] (2)

[0044] Where v0 is the speed of the lifting screen, n is the rotational speed of the drive shaft, and r is the radius of the drive shaft.

[0045] The detection system of this invention consists of a laser rangefinder, a torque sensor, a speed sensor, and an onboard computer installed on a root and tuber crop harvester, thus forming a feed rate detection system for the root and tuber crop harvester. (Reference) Figure 1This invention discloses a feeding quantity detection system for root and tuber crop harvesters, used for real-time detection of the feeding quantity. The system includes a laser rangefinder, a torque sensor, a speed sensor, and an onboard computer. Two laser rangefinders are installed at the front and rear ends of the lifting screen, respectively. The laser rangefinder at the front end of the lifting screen acquires the material thickness at that point, and the laser rangefinder at the rear end acquires the material thickness at that point, transmitting this thickness information to the onboard computer. At least one torque sensor is installed on the end face of the front and / or rear drive shafts to measure the torque of the drive shafts and transmit this torque information to the onboard computer. At least one speed sensor is installed on the front and / or rear drive shafts to measure the speed of the drive shafts and transmit this speed information to the onboard computer. The laser rangefinder, torque sensor, and speed sensor are connected to the onboard computer via an onboard signal processing circuit. The onboard computer is installed in the driver's cab of the root and tuber crop harvester and acquires the various measurement values ​​via serial communication.

[0046] The derivation process of the feed rate formula is explained below.

[0047] Based on the material thickness h2 at the front end of the lifting screen, the structural parameters of the lifting screen (inclination angle α, length l, width b), and the rotational torque M of the drive shaft, the force characteristics of the conveyed material are analyzed to obtain the minimum lifting force F provided by the lifting screen. Figure 2 Analysis of the force characteristics of the material shows that in order to successfully transport the material to the storage box 8 at the rear end of the lifting screen, the lifting screen must provide a lifting force F that can overcome the gravity G and frictional force f of the material on the screen.

[0048] (3)

[0049] In the formula, m is the mass of the material on the lifting screen, kg; μ is the coefficient of friction between the material and the lifting screen; and α is the inclination angle of the lifting screen, °.

[0050] When obtaining the mass of the material on the lifting screen, considering the presence of the triangular vibrating shaft and screen holes, the lifting screen will screen out some soil clods and debris during operation, causing changes in the morphological information and stress characteristics of the soil-bean mixture on the lifting screen (please refer to patents CN116267171A, CN117280935, CN210016971U). In order to ensure the operational stability of the transportation process, the triangular wheel is controlled separately and rotated at a uniform speed, so that the amount of soil screened changes linearly. Reflected in the morphological structure of the mixture on the screen, its lateral area can be considered to be approximately trapezoidal. The mass m of the transported material is calculated in this way, as shown in formula (4).

[0051] (4)

[0052] In the formula, ρ is the density of the material, kg / m³. 3 b is the width of the lifting screen, m; l is the length of the lifting screen, m; h1 is the material thickness at the rear end of the lifting screen, m; h2 is the material thickness at the front end of the lifting screen.

[0053] The conventional formula for calculating the feed rate Q of the lifting screen is:

[0054] (5)

[0055] In the formula, v0 is the material filling coefficient, and v0 is the speed of the lifting screen. (where n is the rotational speed of the drive shaft and r is the radius of the drive shaft).

[0056] Since the material thickness h1 at the rear end of the lifting screen is related to various factors, such as vibration frequency, screen aperture size, conveying speed, and operating conditions, its value is difficult to monitor. However, the material thickness h2 at the front end of the lifting screen is affected by fewer factors, only related to the digging depth and shovel height, and these two are approximately fixed under actual operating conditions, so h2 can be measured. Therefore, according to formulas (3), (4), and (5), when the lifting screen moves at a constant speed, the lifting force F is:

[0057] (6)

[0058] The torque of the upper drive shaft of the lifting screen is .

[0059] The relationship between the feed rate Q of the lifting screen and the torque M of the drive shaft can be obtained as follows:

[0060] (7)

[0061] In formula (7), l, r and α are inherent parameters of the device structure.

[0062] Considering the interference of external factors, such as the unevenness of the harvester's speed and the interference of the external environment, the disturbance amount S is added to formula (7) to reduce the error of the characterization quantity, thus obtaining formula (1).

[0063] Among them, parameter S can be determined based on the actual feed rate measurement. Specifically, in the actual application process, the preset feed rate can be controlled by changing the material mass per unit length of the lifting screen. Then, the torque sensor is used to obtain the torque measurement value of the transmission shaft under different preset feed rates. Combined with formula (1) and using the least squares method, the regression equation between the feed rate and the transmission shaft torque is obtained, thereby determining the error correction value S introduced by various influencing factors.

[0064] The above description is merely a preferred embodiment of the present invention and is not intended to limit the scope of the invention in any way. All equivalent transformations or modifications made in accordance with the essence of the present invention should be covered within the protection scope of the present invention.

Claims

1. A method for detecting the feeding amount of a root and tuber crop harvester, used for real-time detection of the feeding amount of the root and tuber crop harvester, wherein in the conveying mechanism of the root and tuber crop harvester, a lifting screen conveys materials under the action of drive shafts located at its front and rear ends, characterized in that... The method for detecting the feed rate of root and tuber crop harvesters mainly includes the following steps: S1. Measure the material thickness at both ends of the lifting screen. Obtain the material thickness at the front end of the lifting screen through a laser rangefinder installed at the front end of the lifting screen, and obtain the material thickness at the rear end of the lifting screen through a laser rangefinder installed at the rear end of the lifting screen. Then transmit the material thickness information to the on-board computer. S2. Measure the torque of the drive shaft by acquiring the torque of the drive shaft through a torque sensor installed on the end face of the front drive shaft and / or the rear drive shaft; and transmit the torque information of the drive shaft to the on-board computer. S3. Obtain the movement speed of the lifting screen. The rotation speed of the drive shaft is obtained by a speed sensor installed on the front drive shaft and / or the rear drive shaft. The rotation speed information of the drive shaft is transmitted to the on-board computer. The on-board computer can calculate the movement speed of the lifting screen based on the rotation speed of the drive shaft. S4. Obtain the feeding amount value. The on-board computer processes the data of the material thickness at both ends of the lifting screen, the torque of the drive shaft, and the movement speed of the lifting screen to obtain the current feeding amount of the root and tuber crop harvester. In step S4, the formula for calculating the feeding amount is: ， Where Q is the feed rate, v0 is the speed of the lifting screen, h2 is the material thickness at the front end of the lifting screen, M is the torque of the drive shaft, l is the length of the lifting screen, b is the width of the lifting screen, α is the inclination angle of the lifting screen, r is the radius of the drive shaft, and μ is the coefficient of friction between the material and the lifting screen. ρ is the material filling factor, S is the disturbance amount, g is the gravitational acceleration, and ρ is the material density.

2. The method for detecting the feed amount of a root and tuber crop harvester according to claim 1, characterized in that, In step S3, the formula for calculating the speed of the lifting screen is: ， Where v0 is the speed of the lifting screen, n is the rotational speed of the drive shaft, and r is the radius of the drive shaft.

3. A feeding amount detection system for a root and tuber crop harvester, used for real-time detection of the feeding amount in a root and tuber crop harvester, characterized in that, include: A vehicle-mounted computer; Two laser rangefinders are installed at the front and rear ends of the lifting screen, respectively. The laser rangefinder installed at the front end of the lifting screen is used to obtain the material thickness at the front end of the lifting screen, and the laser rangefinder installed at the rear end of the lifting screen is used to obtain the material thickness at the rear end of the lifting screen, and the thickness information is transmitted to the on-board computer. At least one torque sensor is mounted on the end face of the front drive shaft and / or the rear drive shaft to measure the torque of the drive shaft and transmit the torque information of the drive shaft to the on-board computer. At least one speed sensor, mounted on the front drive shaft and / or rear drive shaft, is used to measure the speed of the drive shaft and transmit the speed information of the drive shaft to the on-board computer.

4. The feed rate detection system for a root and tuber crop harvester according to claim 3, characterized in that, The speed sensor is an inductive speed sensor.

5. The feeding amount detection system for a root and tuber crop harvester according to claim 3, characterized in that, The torque sensor is a disc-type torque sensor.

Images