1. A self-adaptive control method of an agricultural machine workbench is characterized by comprising the following steps:

acquiring a contrast relation between the running speed and the damping coefficient;

acquiring the current running speed of the agricultural machine;

judging whether the running speed is matched with a damping coefficient of a damper according to the comparison relation to obtain a first judgment result;

when the first judgment result is yes, maintaining the damping coefficient unchanged;

when the first judgment result is negative, adjusting the damping coefficient to be matched with the running speed so as to reduce the response amplitude of the system; specifically, when the running speed is larger, the damping coefficient is adjusted to be lower; and when the running speed is smaller, the damping coefficient is adjusted to be higher.

2. The adaptive control method for the agricultural machine workbench according to claim 1, wherein the obtaining of the comparison relationship between the operation speed and the damping coefficient comprises:

acquiring collected data, wherein the collected data comprise actual rotation angles of the workbench passing through various obstacles with different heights at various preset speeds when springs with various rigidities and various damping ratios are adopted; the damping ratio reflects the relationship between the damping coefficient and the stiffness of the spring;

carrying out variance analysis according to the acquired data to construct an optimized mathematical model; the mathematical model comprises an angle mean deviation equation and a stability equation, wherein the angle mean deviation equation describes the fitting relationship between the angle mean deviation between the ideal corner and the actual corner when the obstacle passes through and each influence factor, and the stability equation describes the fitting relationship between the operation stability parameter and each influence factor;

performing optimization calculation according to the optimized mathematical model to obtain the optimal damping ratio corresponding to each speed threshold range when the angle mean deviation is minimum and the operation stability parameter is optimal;

and calculating to obtain target values of the damping coefficients corresponding to the speed threshold ranges according to the optimal damping ratio.

3. The adaptive control method of an agricultural machine workbench according to claim 2, wherein the performing analysis of variance according to the collected data and constructing an optimized mathematical model comprises:

calculating the angle average difference and the value of the operation stability parameter corresponding to different numerical value combinations of the influence factors according to an angle average difference formula and an operation stability parameter formula;

carrying out variance analysis on the value of the angular mean deviation to obtain a first significant term which has significant influence on the angular mean deviation, and obtaining a first fitting equation corresponding to the angular mean deviation based on the first significant term, wherein the form of the first fitting equation isWherein:A _j is as followsjThe first significant terms can be in the form of a basic term, a combined term and a nonlinear fitting term, wherein the basic term comprises each influence factor, the combined term is a combination of a plurality of the basic terms, and each basic term has a corresponding nonlinear fitting term;a _j is as followsjA first significant termThe fitting parameters of (1);mis the total number of the first significant term;

performing variance analysis on the value of the operating stability parameter to obtain a second significant term which has significant influence on the operating stability parameter, and obtaining a second fitting equation corresponding to the operating stability parameter based on the second significant term, wherein the second fitting equation is in the form ofWherein:B _k is as followsk(ii) said second significant terms, which may be in the form of said base terms, said combination terms, and said non-linear fit terms;b _k is as followskFitting parameters of each of the second significant terms;ois the total number of the second significant terms.

4. The adaptive control method of an agricultural machine workbench according to claim 1, wherein the determining whether the operating speed is matched with a damping coefficient of a damper according to the comparison comprises:

judging whether the running speed is in a preset speed threshold range corresponding to the current damping coefficient or not, and obtaining a second judgment result;

when the second judgment result is yes, the running speed is matched with the damping coefficient of the damper;

and when the second judgment result is negative, the running speed is not matched with the damping coefficient of the damper.

5. The adaptive control method for the agricultural machine workbench according to claim 4, wherein the adjusting the damping coefficient to match the operation speed to reduce the response amplitude of the system comprises:

obtaining a target value of the damping coefficient according to the threshold range of the running speed;

determining a current value required by the damper according to the target value of the damping coefficient;

the duty ratio of the PWM output voltage is adjusted to change the output voltage, and the input current of the damper is changed through the voltage-current conversion circuit.

6. The adaptive control method of an agricultural machine workbench according to claim 5, wherein the adjusting the duty ratio of the PWM output voltage to change the output voltage and the changing the input current of the damper through the voltage-current conversion circuit further comprises:

acquiring an input voltage value of the damper through a high-precision sampling resistor;

calculating an actual input current of the damper from the input voltage value;

and judging whether the actual input current is within a preset range, if so, adjusting the damping coefficient of the damper, otherwise, continuously adjusting the duty ratio of the PWM output voltage to change the input voltage value of the damper.

7. The adaptive control method for an agricultural machine workstation according to claim 1, wherein the method further comprises:

judging whether the accuracy of system adjustment meets the requirement or not to obtain a third judgment result;

if the third judgment result is yes, maintaining the current damping coefficient unchanged;

and when the third judgment result is negative, continuously adjusting the damping coefficient.

8. The adaptive control method for an agricultural machine workbench according to claim 7, wherein the method comprises:

acquiring support reaction force data of the ground to the support wheels;

and judging whether the supporting reaction force is always greater than 0, if so, indicating that the accuracy of system adjustment meets the requirement.

9. A self-adaptive control system of an agricultural machine workbench is characterized in that a workbench (1) of an agricultural machine is connected with a support wheel (2), the workbench (1) is connected with a frame (4) of the agricultural machine through an elastic device (3), and the elastic device (3) comprises a spring (31); the system is characterized in that the adaptive control system comprises a controller (8), a speed detection element (5) and a damper (32);

the damper (32) belongs to the elastic means (3) and is arranged in parallel with the spring (31); the damper (32) is a magnetorheological damper;

the speed detection element (5) and the damper (32) are both connected with the controller (8), and a voltage-current conversion circuit (6) is arranged between the damper (32) and the controller (8);

the controller (8) is configured to implement the adaptive control method of an agricultural machine workstation according to any one of claims 1 to 6.

Background

Current agricultural machine has been very popular, each link of agricultural production can generally utilize agricultural machine to accomplish, agricultural machine generally includes mobile host and workstation, wherein mobile host is controlled by the people and removes in the field, the workstation is the part that acts on crops, according to the actual demand, the workstation can set to reaping work platform, the seeding workstation, retrieve workstation etc, in some agricultural production links, it is higher to the relative position requirement on workstation and ground, because ground is undulant generally, consequently, need set up self-adaptation device so that the workstation fluctuates along with the fluctuation on ground. During field operation, the working platform is bounced irregularly due to the fact that the ground is fluctuated irregularly, so that the working platform can be separated from the ground sometimes, due to the fact that self-adaptive movement is not timely, harvesting or recovery is omitted due to the fact that the working platform bounces during harvesting or recovery operation, and the impurity content rate of the harvesting or recovery operation can be increased due to the fact that soil shoveling is carried out. The self-adaptation effect that current agricultural machine mainly promoted the workstation through the spring is passive because the rigidity of spring is invariable, and agricultural machine's effect operating mode is the difference very big, can really promote certain self-adaptation motion effect through simple spring, but under different operating modes, agricultural machine's operation effect difference is huge.

Therefore, it is necessary to develop a control method and system, so that the agricultural machine workbench has a better adaptive effect.

Disclosure of Invention

The purpose of the invention is as follows: in order to overcome the defects in the prior art, the invention provides an adaptive control method and a control system of an agricultural machine workbench, which can adjust the adaptive effect of the workbench in real time according to the operation condition of the agricultural machine.

The technical scheme is as follows: in order to achieve the above object, the present invention provides a self-adaptive control method for an agricultural machine workbench, comprising:

acquiring a contrast relation between the running speed and the damping coefficient;

acquiring the current running speed of the agricultural machine;

judging whether the running speed is matched with a damping coefficient of a damper according to the comparison relation to obtain a first judgment result;

when the first judgment result is yes, maintaining the damping coefficient unchanged;

when the first judgment result is negative, adjusting the damping coefficient to be matched with the running speed so as to reduce the response amplitude of the system; specifically, when the running speed is larger, the damping coefficient is adjusted to be lower; and when the running speed is smaller, the damping coefficient is adjusted to be higher.

Further, the obtaining of the comparison relationship between the operation speed and the damping coefficient includes:

acquiring collected data, wherein the collected data comprise actual rotation angles of the workbench passing through various obstacles with different heights at various preset speeds when springs with various rigidities and various damping ratios are adopted; the damping ratio reflects the relationship between the damping coefficient and the stiffness of the spring;

carrying out variance analysis according to the acquired data to construct an optimized mathematical model; the mathematical model comprises an angle mean deviation equation and a stability equation, wherein the angle mean deviation equation describes the fitting relationship between the angle mean deviation between the ideal corner and the actual corner when the obstacle passes through and each influence factor, and the stability equation describes the fitting relationship between the operation stability parameter and each influence factor;

performing optimization calculation according to the optimized mathematical model to obtain the optimal damping ratio corresponding to each speed threshold range when the angle mean deviation is minimum and the operation stability parameter is optimal;

and calculating to obtain target values of the damping coefficients corresponding to the speed threshold ranges according to the optimal damping ratio.

Further, the performing analysis of variance according to the collected data and constructing an optimized mathematical model includes:

calculating the angle average difference and the value of the operation stability parameter corresponding to different numerical value combinations of the influence factors according to an angle average difference formula and an operation stability parameter formula;

carrying out variance analysis on the value of the angular mean deviation to obtain a first significant term which has significant influence on the angular mean deviation, and obtaining a first fitting equation corresponding to the angular mean deviation based on the first significant term, wherein the form of the first fitting equation isWherein:A _j is as followsjThe first significant terms can be in the form of a basic term, a combined term and a nonlinear fitting term, wherein the basic term comprises each influence factor, the combined term is a combination of a plurality of the basic terms, and each basic term has a corresponding nonlinear fitting term;a _j is as followsjFitting parameters of each of the first significant terms;mis the total number of the first significant term;

performing variance analysis on the value of the operating stability parameter to obtain a second significant term which has significant influence on the operating stability parameter, and obtaining a second fitting equation corresponding to the operating stability parameter based on the second significant term, wherein the second fitting equation is in the form ofWherein:B _k is as followsk(ii) said second significant terms, which may be in the form of said base terms, said combination terms, and said non-linear fit terms;b _k is as followskFitting parameters of each of the second significant terms;ois the total number of the second significant terms.

Further, the judging whether the running speed is matched with the damping coefficient of the damper according to the comparison relationship comprises:

judging whether the running speed is in a preset speed threshold range corresponding to the current damping coefficient or not, and obtaining a second judgment result;

when the second judgment result is yes, the running speed is matched with the damping coefficient of the damper;

and when the second judgment result is negative, the running speed is not matched with the damping coefficient of the damper.

Further, said adjusting said damping coefficient to match said operating speed to reduce a response magnitude of the system comprises:

obtaining a target value of the damping coefficient according to the threshold range of the running speed;

determining a current value required by the damper according to the target value of the damping coefficient;

the duty ratio of the PWM output voltage is adjusted to change the output voltage, and the input current of the damper is changed through the voltage-current conversion circuit.

Further, after the adjusting the duty ratio of the PWM output voltage to change the output voltage and the changing the input current of the damper by the voltage-to-current conversion circuit, the method further includes:

acquiring an input voltage value of the damper through a high-precision sampling resistor;

calculating an actual input current of the damper from the input voltage value;

and judging whether the actual input current is within a preset range, if so, adjusting the damping coefficient of the damper, otherwise, continuously adjusting the duty ratio of the PWM output voltage to change the input voltage value of the damper.

Further, the method further comprises:

judging whether the accuracy of system adjustment meets the requirement or not to obtain a third judgment result;

if the third judgment result is yes, maintaining the current damping coefficient unchanged;

and when the third judgment result is negative, continuously adjusting the damping coefficient.

Further, the method comprises:

acquiring support reaction force data of the ground to the support wheels;

and judging whether the supporting reaction force is always greater than 0, if so, indicating that the accuracy of system adjustment meets the requirement.

A self-adaptive control system of an agricultural machine workbench is characterized in that the workbench of an agricultural machine is connected with a support wheel, the workbench is connected with a frame of the agricultural machine through an elastic device, and the elastic device comprises a spring; the self-adaptive control system comprises a controller, a speed detection element and a damper;

the damper belongs to the elastic device and is arranged in parallel with the spring; the damper is a magneto-rheological damper;

the speed detection element and the damper are both connected with the controller, and a voltage-current conversion circuit is arranged between the damper and the controller;

the controller is used for implementing the self-adaptive control method of the agricultural machine workbench.

Has the advantages that: according to the self-adaptive control method and the control system of the agricultural machine workbench, the elastic device with the damper is arranged between the mobile host and the frame of the workbench, and the workbench can have better self-adaptive operation capability by monitoring the running speed of the agricultural machine and adjusting the damping coefficient of the damper in real time according to the running speed.

Drawings

FIG. 1 is a schematic structural view of a workbench system of an agricultural machine;

FIG. 2 is a schematic diagram showing the construction of an adaptive control system of an agricultural machine workbench;

fig. 3 is a schematic flow chart of an adaptive control method for an agricultural machine workbench.

In the figure: 1-a workbench; 2-a support wheel; 3-an elastic device; 31-a spring; 32-a damper; 4-a frame; 5-a speed detection element; 6-a voltage current conversion circuit; 7-ground wheel pressure sensor; 8-a controller.

Detailed Description

The present invention will be further described with reference to the accompanying drawings.

As shown in fig. 1, the working platform system of the agricultural machine of the present invention comprises a working platform 1 and a machine frame 4, wherein the machine frame 4 is fixed on a mobile host machine, and the mobile host machine can be a tractor or a specially designed mobile platform. The rear end of the workbench 1 is hinged on the frame 4, and the front end of the workbench 1 is provided with a supporting wheel 2; furthermore, an elastic means 3 is connected between the table 1 and the frame 4, said elastic means 3 comprising a spring 31.

Based on the above structure, the adaptive control system of the agricultural machine workbench of the invention comprises a controller 8, a speed detection element 5 and a damper 32; the damper 32 belongs to the elastic means 3 and is arranged in parallel with the spring 31; the damper 32 is a magnetorheological damper; as shown in fig. 2, the speed detecting element 5 and the damper 32 are both connected to the controller 8, and a voltage-current conversion circuit 6 is provided between the damper 32 and the controller 8. The speed detecting element 5 may be a rotational speed sensor (encoder) mounted on a driving wheel of the mobile host, or a GPS sensor mounted on an agricultural machine. The controller 8 is used for implementing the adaptive control method of the agricultural machine workbench.

Preferably, the device further comprises a land wheel pressure sensor 7, and the land wheel pressure sensor 7 is connected with the controller 8.

In the above-mentioned workbench system, the supporting wheel 2 is in contact with the ground, and when the supporting wheel 2 is excited by the ground bulge, the comprehensive response formula of the system to the excitation is calculated as follows:

；

wherein the content of the first and second substances,v _y =v _f cosαcosα ₁ ；v _y the vertical speed that the active transient support wheel 2 has;v _f the speed of the active transient support wheel 2;α、α ₁ -external excitation-determined velocity component tilt angle (as shown in figure 1);s(t)-point in timetThe magnitude of the response of the system;m-a table weight;ω _d -the system has a damped natural angular frequency;F(τ)-point in timeτThe pulse force of the ground bulge to the supporting wheel 2;ξ-a damping ratio;ω _n -system undamped natural frequency;x ₀ -the initial displacement the system has;which represents a constant term determined by the initial system conditions.

From the above equation, the response amplitude of the system to the applied excitation is determined bym、ω _d 、ξ、ω _n The characteristics inherent in the system and the speed of the support wheel 2 at the moment of excitationv _f (i.e., the operating speed of the agricultural machine) determined, among other things, bym、ω _d 、ξ、ω _n Is an inherent characteristic of the system, and the corresponding amplitude of the system can be changed by changing the running speed of the agricultural machine due to the difficulty in adjusting the factorsv _f The response amplitude of the system is adjusted.

The model of the workbench system is simulated and tested under the excitation action of the ground bulges with different heights, so that the simulation and testing can be known, and a larger damping coefficient is selected as much as possible during low-speed operation so as to improve the response speed of the system and enable the system to rapidly eliminate the influence of external excitation on the workbench; in high-speed operation, a smaller damping coefficient should be selected as much as possible to reduce the response amplitude of the system.

Based on the above mechanical system, the comprehensive response formula and the relationship between the speed and the response amplitude, as shown in fig. 3, the adaptive control method based on the agricultural machine workbench of the present invention comprises the following steps S101-S105:

step S101, acquiring a comparison relation between the running speed and the damping coefficient;

step S102, acquiring the current running speed of the agricultural machinery;

in this step, the operating speed of the agricultural machine is obtained by reading data generated by the speed detecting element 5.

Step S103, judging whether the running speed is matched with a damping coefficient of a damper according to the comparison relation to obtain a first judgment result;

step S104, when the first judgment result is yes, maintaining the damping coefficient unchanged;

step S105, when the first judgment result is negative, adjusting the damping coefficient to match with the running speed so as to reduce the response amplitude of the system; specifically, when the running speed is larger, the damping coefficient is adjusted to be lower; and when the running speed is smaller, the damping coefficient is adjusted to be higher.

In the steps S101 to S105, the adaptive movement capability of the workbench can be improved by acquiring the current operating speed of the agricultural machine in real time and adjusting the damping coefficient of the damper accordingly, so that the agricultural machine can adaptively and intelligently adjust the damping coefficient to achieve a better operation effect, and a user driving the agricultural machine does not need to frequently adjust the adaptive capability of the workbench according to experience.

Preferably, in order to match the operation speed with the damping coefficient of the damper, a comparison relationship between the two is required as a reference, and in order to obtain the comparison relationship between the two, the step S101 specifically includes the following steps S201 to S204:

step S201, acquiring acquired data, wherein the acquired data comprises actual rotation angles of the workbench passing through various obstacles with different heights at various preset speeds when springs with various rigidities and various damping ratios are adopted; the damping ratio reflects the relationship between the damping coefficient and the stiffness of the spring;

in this step, three influencing factors are involved, namely: speed, spring stiffness, and damping ratio; the obstacles have various specifications, the height of each specification of obstacle is different, and when the workbench passes through the obstacles, different actual rotating angles can be generated by the workbench relative to the rack due to the different heights of the obstacles. In an ideal state, when the workbench passes through an obstacle, the supporting wheels are always in contact with the obstacle, the maximum angle which the workbench rotates in the ideal state is called an ideal rotating angle, and when the workbench actually moves, the supporting wheels can jump, so that the actual rotating angle can deviate from the ideal rotating angle. The three influence factors all have a plurality of selectable values, the combination of different values of each influence factor is taken to carry out experiments, actual corner data can be generated, each actual corner also has a corresponding ideal corner, a database can be obtained by collecting the experiment data, and each piece of data in the database comprises data of speed, rigidity of a spring, damping ratio, actual corners, ideal corners and obstacle height. The acquired data acquired in this step is a part of or all data in the database, and the acquired data is data corresponding to the characteristics of the field to be operated, specifically: firstly, obtaining a highest obstacle estimated value of a field to be operated, wherein the highest obstacle estimated value is obtained by a user through measurement and estimation according to the actual state of the field; then, acquiring data corresponding to a plurality of obstacle height values lower than the highest obstacle estimated value from a database, and taking the data as collected data to participate in subsequent operation, so that subsequent optimization calculation can be guaranteed to be obtained based on the field to be operated;

step S202, carrying out variance analysis according to the acquired data and constructing an optimized mathematical model; the mathematical model comprises an angle mean deviation equation and a stability equation, wherein the angle mean deviation equation describes the fitting relationship between the angle mean deviation between the ideal corner and the actual corner when the obstacle passes through and each influence factor, and the stability equation describes the fitting relationship between the operation stability parameter and each influence factor;

in the step, the main purpose is to construct the relationship between the influence factors and the angle mean deviation and the relationship between the influence factors and the stability parameters, namely, the angle mean deviation equation and the stability equation are reconstructed by taking the influence factors as the key elements, so that the optimization calculation can be performed through the constraint conditions of the influence factors in the subsequent process, and the optimization calculation becomes simple.

Step S203, carrying out optimization calculation according to the optimization mathematical model to obtain the optimal damping ratio corresponding to each speed threshold range when the angle mean deviation is minimum and the operation stability parameter is optimal;

and step S204, calculating to obtain target values of the damping coefficients corresponding to the speed threshold ranges according to the optimal damping ratio.

In the step, the relation between the damping ratio and the damping coefficient is determined by a formulaConverting, wherein:cin order to be a damping coefficient of the damping,ξin order to achieve a damping ratio,min order to obtain the quality of the working table,kis the stiffness of the spring.

In the step, the speed is divided into a plurality of speed threshold value ranges, and each speed threshold value range corresponds to an optimal damping coefficient, so that when the agricultural machinery is in one speed threshold value range, the damper can be always kept at one damping coefficient, and frequent adjustment of the damping coefficient can be avoided.

Further, the performing analysis of variance according to the collected data in the step S202 and the constructing an optimized mathematical model include the following steps S301 to S303:

step S301, calculating the values of the angle mean difference and the operation stability parameter corresponding to different numerical combinations of the influencing factors according to an angle mean difference formula and an operation stability parameter formula;

in this step, the angle mean difference formula isWherein, in the step (A),δis the angle mean deviation;θ _i to correspond toiThe desired angle of rotation of each of the obstacles,to correspond toiThe actual turning angle of each of the obstacles;nis the total number of said obstacles; the operation stability parameter formula isWherein, in the step (A),Wfor the operating stability parameter, a smaller value indicates a higher stability. The above-mentioned angle mean deviation formula describes the average number of differences between the ideal rotation angle and the actual rotation angle in all the collected data; the stability parameter describes the ratio of the standard deviation of mean deviation between the ideal corner and the actual corner in all the collected data to the mean deviation of the angle, and the ratio can reflect the operation stability of the workbench.

Step S302, performing variance analysis on the value of the angular mean deviation to obtain a first significant term which has significant influence on the angular mean deviation, and obtaining a first fitting equation corresponding to the angular mean deviation based on the first significant term, wherein the form of the first fitting equation isWherein:A _j is as followsjThe first significant terms can be in the form of a basic term, a combined term and a nonlinear fitting term, wherein the basic term comprises each influence factor, the combined term is a combination of a plurality of the basic terms, and each basic term has a corresponding nonlinear fitting term;a _j is as followsjFitting parameters of each of the first significant terms;mis the total number of the first significant term;

in this step, variance analysis is performed on the value of the angle mean difference, so that items corresponding to the items in the set confidence interval can be obtainedPWhen the value is smaller than a set threshold value, the items meeting the conditions are taken as first significant items, and when the variance analysis is carried out on the value of the angle mean deviation, the related items comprise basic items, combination items, nonlinear fitting items, residual errors, mismatching items and errors, wherein the basic items are the speed, the rigidity of the spring and the damping ratio, and the three influencing factors (the speed, the rigidity of the spring and the damping ratio) are respectively represented by X, Y, Z; the above combination term includes XY, YZ, XZ, and XY is taken as an example, which represents a combination term composed of two influencing factors of X and Y, and the combination term can influence the angle difference if it influences the angle differenceIf the angle mean difference has obvious influence, the combination item is used as an obvious item to participate in the fitting of the angle mean difference equation; the non-linear fit term includes X²、Y²And Z²If any one of the terms has a significant influence on the angular mean deviation, the term can be used as a significant term to participate in fitting the angular mean deviation equation. The influence significance of residual errors, mismatching terms and errors on the angle mean deviation is small, and the residual errors, the mismatching terms and the errors do not generally participate in the fitting of the angle mean deviation equation.

Step S303, performing variance analysis on the value of the operation stability parameter to obtain a second significant term which has significant influence on the operation stability parameter, and obtaining a second fitting equation corresponding to the operation stability parameter based on the second significant term, wherein the form of the second fitting equation isWherein:B _k is as followsk(ii) said second significant terms, which may be in the form of said base terms, said combination terms, and said non-linear fit terms;b _k is as followskFitting parameters of each of the second significant terms;ois the total number of the second significant terms.

In this step, the method for obtaining the second significant term by screening the items and the method for fitting the stability equation using the second significant term are the same as those in step S302, and are not described herein again.

Preferably, in step S203, when the optimization calculation is performed according to the optimized mathematical model to obtain the minimum angle mean deviation and the optimum operation stability parameter, the optimum damping ratio corresponding to each speed threshold range includes:

and constructing an objective function in the constraint condition and carrying out optimization calculation according to the constraint condition. Here, the objective function is minδAnd minWThat is, the angle mean deviation equation and the operation stability parameter are minimized, the constraint condition includes the spring stiffness, the speed threshold range and the adjustment interval of the damping ratio, wherein the spring stiffness is determined, and the optimal damping ratio corresponding to each speed threshold range can be obtained through the constraint condition and the objective function.

Preferably, the step S103 of determining whether the operating speed matches the damping coefficient of the damper according to the comparison relationship includes the following steps S401 to S403:

step S401, judging whether the running speed is in a preset speed threshold range corresponding to the current damping coefficient, and obtaining a second judgment result;

step S402, when the second judgment result is yes, the running speed is matched with the damping coefficient of the damper;

step S403, if the second determination result is negative, the operating speed is not matched with the damping coefficient of the damper.

Preferably, the adjusting the damping coefficient to match the operation speed in step S105 to reduce the response amplitude of the system includes the following steps S501-S503:

step S501, obtaining a target value of the damping coefficient according to a threshold range of the running speed;

step S502, determining a current value required by the damper according to the target value of the damping coefficient;

in step S503, the duty ratio of the PWM output voltage is adjusted to change the output voltage, and the input current of the damper is changed by the voltage-current conversion circuit.

Preferably, after the adjusting the duty ratio of the PWM output voltage to change the output voltage and the changing the input current of the damper by the voltage-to-current conversion circuit in step S503, the following steps S601-S603 are further included:

step S601, collecting an input voltage value of the damper through a high-precision sampling resistor;

step S602, calculating the actual input current of the damper according to the input voltage value;

step S603, determining whether the actual input current is within a preset range, if so, completing adjustment of the damping coefficient of the damper, otherwise, continuously adjusting the duty ratio of the PWM output voltage to change the input voltage value of the damper.

Preferably, the method further comprises the following steps S701-S703:

step S701, judging whether the accuracy of system adjustment meets the requirement or not to obtain a third judgment result;

step S702, when the third judgment result is yes, maintaining the current damping coefficient unchanged;

and step S703, when the third judgment result is negative, continuing to adjust the damping coefficient.

Specifically, the step S701 of determining whether the accuracy of the system adjustment meets the requirement includes the following steps S801 to S804:

step S801, acquiring support reaction force data of the ground to the support wheels;

step S802, judging whether the supporting reaction force is always greater than 0;

in this step, it can be examined whether the support reaction force is always greater than 0 within a period of time after the damping coefficient is adjusted.

Step S803, when the supporting counter force is always greater than 0, the accuracy of system adjustment meets the requirement;

and step S804, when the supporting counterforce is not always larger than 0, adjusting the damping coefficient to enable the accuracy of system adjustment to meet the requirement.

In the step, during adjustment, the damping coefficient is increased by a set value every time, whether the supporting counterforce is always greater than 0 is inspected in set time, if yes, the adjustment of the damping coefficient is stopped, otherwise, the damping coefficient is increased by a set value, whether the supporting counterforce is always greater than 0 is inspected in set time again, and the steps are repeated in a circulating mode until the damping coefficient meets the requirements.

Preferably, the step S802 further comprises the following steps a 1-A3:

step A1, judging whether the minimum supporting reaction force in a set time period is always smaller than a set threshold value;

in this step, the set time period starts after the damping coefficient is adjusted.

Step A2, when the minimum supporting counterforce in the set time period is always smaller than the set threshold value, the accuracy of the system adjustment meets the requirement;

and step A3, when the minimum supporting counterforce in the set time period is not always smaller than the set threshold value, adjusting the damping coefficient to ensure that the accuracy of system adjustment meets the requirement.

In the step, during adjustment, the damping coefficient is reduced by a set value every time, whether the minimum supporting counter force is always smaller than a set threshold value or not is examined within set time, if yes, the adjustment of the damping coefficient is stopped, otherwise, the damping coefficient is reduced by a set value, whether the minimum supporting counter force is always smaller than the set threshold value or not is examined within set time again, and the steps are repeated in this way until the damping coefficient meets the requirements.

And after the adjustment is finished, associating the damping coefficient after the adjustment with the speed threshold range, and modifying the comparison relation between the running speed and the damping coefficient, so that the damping coefficient associated with the speed threshold range is taken as a starting point and is finely adjusted near the numerical value of the starting point, the damping coefficient which is more fit with the actual working condition can be obtained, the adjustment is rapid, and the adjustment accuracy is high.

In step S801, the support reaction force of the support wheel is acquired from the data acquired by the ground wheel pressure sensor 7.

Preferably, the following step S901 is further included between the above step S202 and step S203:

step S901, carrying out optimization calculation according to the optimization mathematical model and outputting a recommended spring rigidity value;

specifically, in step S901, the objective function of the optimization calculation is minδAnd minWThat is, the above equation of mean angle difference and the operational stability parameter are minimized, and the constraint conditions include: the value range of the spring stiffness, the speed threshold range, and the adjustment interval of the damping ratio can obtain a recommended spring stiffness value and also can obtain an optimal operating speed and a corresponding damping ratio through the constraint conditions and the objective function, and when performing optimization calculation in step S203, the spring stiffness in the optimization conditions adopts the recommended spring stiffness value or an integer value (e.g., the recommended spring stiffness value is 9.7N/mm, and the integer value is 10N/mm) corresponding to the recommended spring stiffness value as a fixed value. Based on the method, before the user drives the agricultural machine to work, the user firstly drives the agricultural machine to workThe spring 31 in the elastic means 3 is exchanged for a spring having a stiffness of 9.7N/mm or 10N/mm.

According to the self-adaptive control method and the control system of the agricultural machine workbench, the elastic device with the damper is arranged between the mobile host and the frame of the workbench, and the workbench can have better self-adaptive operation capability by monitoring the running speed of the agricultural machine and adjusting the damping coefficient of the damper in real time according to the running speed.

The above description is only of the preferred embodiments of the present invention, and it should be noted that: it will be apparent to those skilled in the art that various modifications and adaptations can be made without departing from the principles of the invention and these are intended to be within the scope of the invention.