CN110235601A - Combine harvester cut stubble height automatic control system and control method - Google Patents

Abstract

The invention discloses an automatic control system and control method for a combine harvester cutting height, comprising a mechanical contact sensor, an ultrasonic sensor, a hydraulic system and a controller for adjusting the cutting height. The combination of mechanical contact sensor and ultrasonic sensor detects the height of the header from the ground to improve the accuracy of detection and reduce the error of single sensor detection. Among them, the mechanical contact sensor drives the angle sensor to rotate through the profiling plate, and then calculates the height above the ground, and the mechanical contact sensor can realize the rotation when the combine harvester reverses and turns, so as to ensure that the profiling plate will not be stuck and broken. The mechanical contact sensor and the ultrasonic sensor detect the signal and transmit it to the controller. After the controller calculates and processes, the hydraulic cylinder is adjusted through the proportional valve to make the cutting table go up and down, and finally ensure that the height of the stubble is kept within a certain range.

Description

Combine harvester cut stubble height automatic control system and control method

technical field

The invention belongs to the field of agricultural machinery automation, and in particular relates to an automatic control system and a control method for a combine harvester cutting stubble height.

Background technique

The output of combine harvesters in my country is large but the level of automation is not high. In recent years, the automation of combine harvesters in my country is developing continuously. Realizing the automatic adjustment and control of the stubble cutting height of the combine harvester to ensure stable stubble retention will help to obtain a stable feeding amount, reduce grain loss, and facilitate the next plowing. At present, the regulation of stubble cutting height is mainly done manually by the driver based on experience, and the labor intensity of the driver is high. In the prior art, there is a device that uses a profiling board to control the height of the stubble, but the profiling board is easy to sink in the soft paddy field, and there will be a large error when encountering straw, and the profiling board is affected when the harvester turns. Lateral force affects the performance of the profiling board; there are also systems that use ultrasonic sensors to control the stubble height, but ultrasonic sensors are easily affected by debris such as straw and soil clods. Therefore, there is a large error and low reliability when using a single sensor to detect the stubble height. At present, there is no reliable system to regulate the stubble height.

Contents of the invention

The purpose of the present invention is to provide an automatic control system and control method for the stubble height of the combine harvester, so as to solve the problem of poor reliability of the current single sensor for the control of the stubble height, reduce the driver's work intensity, and improve the accuracy of the stubble height control .

The present invention achieves the above object through the following technical solutions:

Combine harvester stubble height automatic regulation system, including ultrasonic sensor, mechanical contact sensor, hydraulic system and controller, mechanical contact sensor installed on both sides of combine harvester header and behind the cutter, ultrasonic sensor installed on Inside the grain dividers on both sides of the combine harvester, ultrasonic sensors and mechanical contact sensors transmit the collected information to the controller, and the controller adjusts the header height through the hydraulic system.

In the above solution, the mechanical contact sensor includes a profiling plate and an angle sensor, one end of the profiling plate is set on the sensing shaft of the angle sensor, the angle sensor is installed on the thin plate of the connector, and the stepped shaft of the connector is installed on the shell On the body, the shell is installed on the mounting bracket, the side of the thin plate away from the stepped shaft is provided with a square rod, and a reset torsion spring is provided between the shell and the front and rear sides of the mounting bracket, and the sensing shaft of the angle sensor is covered with a torsion spring.

In the above scheme, two first cylinders are provided at the front and rear ends of the housing, and second cylinders are provided at the front and rear ends of the mounting bracket. on the cylinder.

In the above solution, the lower end of the torsion spring is clamped on the upper surface of the profile plate, and the two ends are clamped on the stepped shaft of the connecting piece.

In the above solution, the profiled plate is an arcuate curved narrow thin plate.

The automatic control method of the stubble height of the combine harvester. The ultrasonic sensor and the mechanical contact sensor detect the height above the ground and send it to the controller. The controller converts the received signal into the stubble height value, and calculates the average value of the effective data as the current Stubble height, to judge whether the current stubble height is within the set stubble height range, if not, the controller calculates the expansion and contraction of the hydraulic cylinder from the current stubble height value, and drives the hydraulic cylinder to control the lifting of the header by adjusting the proportional valve.

Further, the formula for converting the result detected by the mechanical contact sensor into the stubble height is: H=S*cosα-h, where α is the angle value measured by the angle sensor, H is the height of the cutter from the ground, and h is the height of the machine The vertical distance between the installation position of the touch sensor and the cutting knife, S is the distance from the rotation center of the sensing shaft on the mechanical touch sensor to the contact point between the profiling plate and the ground.

Further, the formula of the expansion and contraction of the hydraulic cylinder is: Among them, L is the expansion and contraction amount of the hydraulic cylinder, A is the distance from the center of rotation of the header to the position of the cutter, B is the distance from the center of rotation of the header to the contact point between the hydraulic cylinder and the header, and C is the distance from the center of rotation of the header to the center of rotation of the hydraulic cylinder D is the vertical distance between the center of rotation of the header and the ground; E is the length of the initial position of the hydraulic cylinder; The angle between the lines, θ is the angle between the line connecting the hydraulic cylinder and header contact point to the header turning center and the line connecting the hydraulic cylinder turning center to the header turning center, β is the hydraulic cylinder turning center The angle between the line to the center of rotation of the header and the vertical direction.

Compared with prior art, the beneficial effect of the present invention is:

(1) the present invention uses ultrasonic sensor and two kinds of sensors of mechanical contact sensor to detect stubble height, two kinds of sensors are respectively positioned at the front and back of cutting knife, can more accurately calculate the height of cutting knife from the ground by the measurement of two kinds of sensors, improve The accuracy of detection, the error reduction of single sensor detection, and the realization of stable stubble cutting without manual intervention.

(2) The mechanical contact sensor in the present invention is composed of a profiling plate, a connector, an angle sensor, a bearing with seat, a shell, and a torsion spring. When the combine harvester reverses, the angle sensor in the mechanical contact sensor will rotate and lift around the axis of the connecting piece, so as to ensure that the profiling plate will not be stuck and broken; when the combine harvester turns, the mechanical contact sensor will The sensor as a whole can rotate around the axis of the housing, and the mechanical contact sensor resets under the action of the reset torsion spring and gravity after the steering is completed.

Description of drawings

Figure 1 is a schematic diagram of the sensor installation location;

Fig. 2 is a structural schematic diagram of a mechanical contact sensor;

Figure 3 is a schematic diagram of the main parts of the mechanical contact sensor, Figure 3(a) is a schematic diagram of the shell structure, Figure 3(b) is a schematic diagram of the connector structure, Figure 3(c) is a schematic diagram of the structure of the mounting bracket, Figure 3(d) ) is a structural schematic diagram of the profiling plate, Fig. 3 (e) is a structural schematic diagram of a reset torsion spring, and Fig. 3 (f) is a structural schematic diagram of a torsion spring;

Fig. 4 is a schematic diagram of the installation position of the ultrasonic sensor, Fig. 4 (a) is a three-dimensional diagram of the installation position of the ultrasonic sensor, and Fig. 4 (b) is a front view of the installation position of the ultrasonic sensor;

Fig. 5 is a block diagram of the header hydraulic system;

Fig. 6 is a flow chart of stubble cutting height control;

Fig. 7 is a schematic diagram for calculating the amount of expansion and contraction of the hydraulic cylinder.

Among them, 1-grain divider, 2-ultrasonic sensor, 3-cutter, 4-mechanical contact sensor, 5-hydraulic cylinder, 6-housing, 7-connecting piece, 8-installation bracket, 9-profile plate , 10-angle sensor, 11-return torsion spring, 12-torsion spring, 13-set screw, 14-bearing with seat, 15-L type mounting plate, 601-first stepped shaft, 602-first cylinder, 701-second stepped shaft, 702-square rod, 801-second cylinder.

Detailed ways

The present invention will be further described below in conjunction with the accompanying drawings, but the protection scope of the present invention is not limited thereto.

The present embodiment describes the specific content of the present invention in conjunction with the crawler-type rice-wheat combine harvester.

As shown in Figure 1, the automatic regulation system of the stubble height of the combine harvester includes an ultrasonic sensor 2, a mechanical contact sensor 4, a hydraulic system 5 for adjusting the height of the stubble, and a controller. The mechanical contact sensor 4 is installed on both sides of the header of the combine harvester, and behind the cutter 3;

As shown in Figures 2 and 3, the mechanical contact sensor 4 is composed of a housing 6, a connector 7, a mounting bracket 8, a profiling plate 9, an angle sensor 10, two reset torsion springs 11, a torsion spring 12, and a set screw 13 , Four belt seat bearings 14 are formed. Fig. 3(a) is the housing 6, the front and rear ends of the housing 6 are respectively welded with a first stepped shaft 601 and two first cylinders 602, and the left and right ends are respectively provided with two circular holes. Wherein, the first stepped shaft 601 is installed in the belt seat bearing 14 of the mounting bracket. When the copy plate 9 is subjected to lateral force, the whole housing 6 including the internal parts of the housing can rotate around the first stepped shaft 601; When the first cylindrical body 602 rotates, it is reset by the reset torsion spring 11; the two round holes at the left and right ends are used to install the bearing with seat 14. Fig. 3(b) is a connecting piece 7, which is welded by a second stepped shaft 701 and a thin plate. Wherein, the second stepped shaft 701 is installed in the belt seat bearing 14 of the housing. When the combine harvester is reversing, the angle sensor 10 and the connecting piece 7 can rotate around the second stepped shaft 701; a large circular hole and two A small round hole is used to install the angle sensor 10; a square bar 702 is extended away from the second stepped shaft 701 side of the thin plate, and the square bar 702 plays a position-limiting role when the combine harvester is working normally, and the limit angle sensor 10 is around the second The stepped shaft 701 turns downward. Fig. 3 (c) is the mounting bracket 8, the front and rear ends of the mounting bracket 8 are respectively provided with two round holes and a second cylinder 801, and the side is provided with four round holes, and the positions of the two round holes at the front and rear ends ensure that the housing 6 will not interfere with the mounting bracket 8 when rotating. Wherein, the two round holes at the front and rear ends are used to install the belt seat bearing 14, and the second cylinder 801 is used to install the return torsion spring 11; the four round holes on the side are used to install the whole mechanical contact sensor 4 on the combine harvester. side of the table. Fig. 3 (d) is the profiling plate 9, the profiling plate 9 is bow-shaped, and is composed of a narrow thin plate with a curved surface and an annular cylinder. The annular cylinder is sleeved on the sensing shaft of the angle sensor 10, and a circular hole is arranged on the annular cylinder. , the profile plate 9 is fixed on the shaft of the angle sensor 10 by a set screw 13 . FIG. 3( e ) shows the return torsion spring 11 , the return torsion spring 11 is sleeved on the second cylinder 801 , and both ends of the return torsion spring 11 are stuck on the first cylinder 602 of the housing 6 . Fig. 3 (f) is the torsion spring 12, the torsion spring 12 is sleeved on the sensing shaft of the angle sensor 10, the lower end of the torsion spring 12 is stuck on the upper surface of the profiling plate 9, and the two ends of the torsion spring 12 are stuck on the second end of the connector 7. Step shaft 701 . The torsion spring 12 is used to give the profiling plate 9 a downward force all the time, so that the profiling plate 9 is kept in contact with the ground all the time. When the combine harvester is working, the profiling plate 9 is in contact with the ground all the time, and the degree of curvature of the profiling plate 9 changes with the undulation of the ground. The angle sensor 10 can measure the angle change value of the profiling plate 9, and then calculate the height change of the stubble. When the combine harvester is reversing, since the profiled plate 9 will be subjected to a force along the direction of the profiled plate, the angle sensor 10 will rotate and lift around the second stepped shaft 701, thereby ensuring that the profiled plate 9 will not be stuck and broken. When the combine harvester turns, because the profiling plate 9 is subjected to the lateral force from the soil or straw, the mechanical contact sensor will rotate around the first stepped axis 601 of the housing 6 as a whole, and the mechanical contact sensor will reset after the steering is completed. Reset under the action of torsion spring 11 and gravity.

As shown in Figure 4, the ultrasonic sensor 2 is installed inside the grain divider 1 of the combine harvester. The bottom of the combine harvester grain divider 1 is not provided with a bottom plate and one side is not provided with a side plate, which will not affect the work of the ultrasonic sensor; 1. An L-shaped mounting plate 15 is installed inside the rear plate, and the ultrasonic sensor 2 is installed on the L-shaped mounting plate 15 through bolts, and the ultrasonic sensor 2 is set facing the ground.

As shown in Figure 5, the hydraulic system 5 used to adjust the stubble height includes a hydraulic oil pump, a relief valve, a proportional valve, and a hydraulic cylinder. The hydraulic cylinder is connected to the hydraulic oil pump through the proportional valve to form a circuit, and the relief valve is connected in parallel in the circuit. The proportional valve continuously controls the load flow or pressure according to the electrical signal output by the controller, and then controls the hydraulic cylinder to make the header reach the predetermined height.

As shown in Figure 6, when the combine harvester is working, it includes the following steps:

S1: Initialize, set the allowable stubble height range and sensor performance parameters and position parameters;

S2: Determine whether manual operation by the driver is required. If manual operation is performed, the automatic control system for stubble height of the combine harvester will not be used, otherwise proceed to the next step;

S3: Ultrasonic sensors and mechanical contact sensors detect their own height from the ground, and send the detected signals to the controller;

S4: The controller receives the signals of two mechanical contact sensors and two ultrasonic sensors, converts the signals of the four sensors into stubble height values, and eliminates the wrong data, that is, the data that is very different from the last output stubble height value , taking the remaining valid data to calculate the average value as the current stubble height; among them, the method of calculating the stubble height through the angle value measured by the mechanical contact sensor is as follows:

As shown in Figure 7, the stubble cutting height is the height H of the cutting knife from the ground, which can be obtained by the deformation (2) of the formula (1), where α is the angle value measured by the angle sensor 10, and h is the installation angle of the mechanical contact sensor. The vertical distance from the position to the cutter, S is the distance from the rotation center of the sensing shaft on the mechanical contact sensor to the contact point between the profiling plate and the ground, h and S are known quantities.

H=S*cosα-h (2)

S5: After calculating the current stubble height, judge whether the current stubble height is within the set stubble height range, if the current stubble height is within the set stubble height range, return to S2; if the current stubble height is not within the set stubble height If it is within the range of the stubble height, proceed to the next step;

S6: The controller calculates the expansion and contraction amount of the hydraulic cylinder from the current stubble height value, and drives the hydraulic cylinder to control the lifting of the header by adjusting the proportional valve. When the current stubble height is greater than the set maximum value, the proportional valve spool moves to the right position, and the hydraulic pressure The cylinder is shortened, and the header is lowered; when the current stubble height is less than the set minimum value, the proportional valve spool moves to the left position, the hydraulic cylinder is extended, and the header rises; among them, the expansion and contraction of the hydraulic cylinder is calculated by the current stubble height value Methods as below:

As shown in Figure 7, the expansion and contraction amount L of the hydraulic cylinder can be jointly obtained by formulas (3) and (4). Among them, A is the distance from the center of rotation of the header to the position of the cutter, B is the distance from the center of rotation of the header to the contact point between the hydraulic cylinder and the header, C is the distance from the center of rotation of the header to the center of rotation of the hydraulic cylinder, and D is the rotation of the header The vertical distance between the center and the ground, E is the length of the initial position of the hydraulic cylinder, γ is the angle between the line from the cutting knife position to the center of rotation of the header and the line from the contact point of the hydraulic cylinder to the header to the center of rotation of the header , θ is the angle between the line connecting the hydraulic cylinder and header contact point to the header turning center and the line connecting the hydraulic cylinder turning center to the header turning center, β is the connection between the hydraulic cylinder turning center and the header turning center The angle between the line and the vertical direction, where A, B, C, D, E, γ, β are all known quantities.

(E+L) ² ＝B ² +C ² -2BCcosθ (4)

The examples are preferred embodiments of the present invention, but the present invention is not limited to the above-mentioned embodiments. On the premise of not departing from the essence of the present invention, any obvious improvements, substitutions or variations that can be made by those skilled in the art belong to the protection scope of the present invention.

Claims (8)

1. The automatic control system of the stubble height of the combine harvester is characterized in that it includes an ultrasonic sensor (2), a mechanical contact sensor (4), a hydraulic system (5) and a controller, and the mechanical contact sensor (4) is installed on the joint On both sides of the header of the harvester and behind the cutter (3), the ultrasonic sensor (2) is installed inside the grain divider (1) on both sides of the combine harvester, the ultrasonic sensor (2) and the mechanical contact sensor (4) The collected information is transmitted to the controller, and the controller adjusts the header height through the hydraulic system (5). 2. the combined harvester cut stubble height automatic control system according to claim 1, is characterized in that, described mechanical contact sensor (4) comprises profiling plate (9), angle sensor (10), profiling plate ( 9) One end is sleeved on the sensing shaft of the angle sensor (10), the angle sensor (10) is installed on the thin plate of the connector (7), the stepped shaft of the connector (7) is installed on the housing (6), and the housing The body (6) is installed on the mounting bracket (8), the side of the thin plate away from the ladder shaft is provided with a square rod, and a reset torsion spring (11) is provided between the shell (6) and the front and rear sides of the mounting bracket (8), and the angle A torsion spring (12) is sleeved on the sensing shaft of the sensor (10). 3. The automatic control system for stubble cutting height of combine harvester according to claim 2, characterized in that, two first cylinders (602) are set at the front and rear ends of the housing (6), and the front and rear ends of the mounting bracket (8) A second cylinder (801) is provided, the return torsion spring (11) is installed in the middle on the second cylinder (801), and both ends are clamped on the first cylinder (602) of the casing (6). 4. The combined harvester stubble height automatic control system according to claim 2, characterized in that, the lower end of the torsion spring (12) is stuck on the upper surface of the profiling plate (9), and the two ends are stuck on the connecting piece (7) ) on the stepped axis. 5 . The automatic regulation system for stubble cutting height of combine harvester according to claim 2 , characterized in that, the profiling plate ( 9 ) is an arcuate curved narrow thin plate. 5 . 6. The method for automatic regulation of the stubble height of the combine harvester, characterized in that the ultrasonic sensor and the mechanical contact sensor detect the height above the ground and send it to the controller, and the controller converts the received signal into the stubble height value, and the calculation is effective The average value of the data is used as the current stubble height to determine whether the current stubble height is within the set stubble height range. If not, the controller calculates the expansion and contraction of the hydraulic cylinder from the current stubble height value, and drives the hydraulic cylinder by adjusting the proportional valve. Control header up and down. 7. The method for automatic regulation and control of the stubble height of the combine harvester according to claim 6, wherein the formula for converting the result detected by the mechanical contact sensor into the stubble height is: H=S*cosα-h, wherein α is the angle value measured by the angle sensor, H is the height of the cutter from the ground, h is the vertical distance from the installation position of the mechanical contact sensor to the cutter, S is the rotation center of the sensing shaft on the mechanical contact sensor to the profiling plate and the ground The distance of the contact point. 8. according to claim 6 or 7 described combine harvester cut stubble height automatic control method, it is characterized in that, the formula of described hydraulic cylinder expansion and contraction is: Among them, A is the distance from the center of rotation of the header to the position of the cutter, B is the distance from the center of rotation of the header to the contact point between the hydraulic cylinder and the header, C is the distance from the center of rotation of the header to the center of rotation of the hydraulic cylinder, and D is the rotation of the header The vertical distance between the center and the ground, E is the length of the initial position of the hydraulic cylinder, γ is the angle between the line from the cutting knife position to the center of rotation of the header and the line from the contact point of the hydraulic cylinder to the header to the center of rotation of the header , θ is the angle between the line connecting the hydraulic cylinder and header contact point to the header turning center and the line connecting the hydraulic cylinder turning center to the header turning center, β is the connection between the hydraulic cylinder turning center and the header turning center The angle between the line and the vertical direction.