阅读说明：本技术 一种机具下降稳定控制方法、系统及拖拉机 (Machine descending stability control method and system and tractor ) 是由 张笑 张露云 张洪波 秦浩良 于 2021-07-27 设计创作，主要内容包括：本发明公开了拖拉机技术领域的一种机具下降稳定控制方法、系统及拖拉机。主泵的出口分别与主溢流阀、定差溢流阀和机具控制阀的入口相连；机具控制阀的出油口经稳态节流阀与定差溢流阀的弹簧腔相连,同时机具控制阀的出油口与开关阀的入口相连；开关阀的出油口与悬挂机构中的悬挂油缸的无杆腔相连；悬挂油缸的无杆腔同时与下降阀的入口相连；悬挂油缸的有杆腔与二次溢流阀的入口相连；位置传感器、力传感器、下降旋钮、目标位置设置旋钮和下降速度设置旋钮分别与控制器的输入端电连接；控制器的输出端分别与机具控制阀的电磁阀、下降阀的电磁阀和开关阀的电磁阀电连接；具有微动性好、启动平稳、下降速度可控、下降过程平稳等特点。(The invention discloses a machine descending stability control method and system and a tractor in the technical field of tractors. The outlet of the main pump is respectively connected with the main overflow valve, the fixed-difference overflow valve and the inlet of the machine tool control valve; the oil outlet of the machine tool control valve is connected with the spring cavity of the constant difference overflow valve through the steady-state throttle valve, and the oil outlet of the machine tool control valve is connected with the inlet of the switch valve; an oil outlet of the switch valve is connected with a rodless cavity of a suspension oil cylinder in the suspension mechanism; a rodless cavity of the suspension oil cylinder is simultaneously connected with an inlet of the descending valve; a rod cavity of the suspension oil cylinder is connected with an inlet of the secondary overflow valve; the position sensor, the force sensor, the descending knob, the target position setting knob and the descending speed setting knob are respectively and electrically connected with the input end of the controller; the output end of the controller is respectively and electrically connected with the electromagnetic valve of the machine tool control valve, the electromagnetic valve of the descending valve and the electromagnetic valve of the switch valve; the device has the characteristics of good micro-mobility, stable starting, controllable descending speed, stable descending process and the like.)

1. A machine descent stabilization control system, comprising: the outlet of the main pump is respectively connected with the inlet of the main overflow valve, the inlet of the fixed-difference overflow valve and the inlet of the machine tool control valve;

the oil outlet of the machine tool control valve is connected with the spring cavity of the constant difference overflow valve through the steady-state throttle valve, and the oil outlet of the machine tool control valve is connected with the inlet of the switch valve;

an oil outlet of the switch valve is connected with a rodless cavity of a suspension oil cylinder in the suspension mechanism; a rodless cavity of the suspension oil cylinder is simultaneously connected with an inlet of the descending valve; a rod cavity of the suspension oil cylinder is connected with an inlet of the secondary overflow valve;

the position sensor, the force sensor for collecting the load information of the suspension mechanism, the descending knob, the target position setting knob and the descending speed setting knob are respectively and electrically connected with the input end of the controller; the output end of the controller is respectively and electrically connected with the electromagnetic valve of the machine tool control valve, the electromagnetic valve of the descending valve and the electromagnetic valve of the switch valve.

2. The implement drop stability control system of claim 1, wherein the suspension mechanism is a three-point suspension mechanism and the force sensor is a pin-type pull/pressure sensor of a lower link of the three-point suspension mechanism and a lower hinge point of the tractor body.

3. The implement drop stability control system of claim 1, wherein the hitch mechanism is a three-point hitch mechanism and the force sensor is a pressure sensor mounted within a rodless chamber of the hitch cylinder.

4. The implement drop stability control system of claim 1, wherein the suspension mechanism is a three-point suspension mechanism and the position sensor is an angle sensor fixed to the lift shaft.

5. The implement drop stability control system of claim 1, wherein the hitch mechanism is a three-point hitch mechanism and the position sensor is a displacement sensor for sensing a stroke of a piston of the hitch cylinder.

6. A machine descending stability control method, characterized in that the machine descending stability control system according to any one of claims 1 to 5 is adopted, and the method comprises the following steps:

the descending knob inputs a descending instruction to the controller;

the controller reads the load information of the suspension mechanism collected by the force sensor and compares the load information with a set value;

when the load information of the suspension mechanism acquired by the force sensor is smaller than a set value, the controller selects a no-load or light-load mode to control the machine tool to descend;

when the load information of the suspension mechanism acquired by the force sensor is larger than or equal to a set value, the controller selects a medium load/heavy load mode to control the machine tool to descend.

7. The implement drop stabilization control method of claim 6, wherein when the load information of the suspension mechanism collected by the force sensor is less than a set value, the controller selects an idle or light load mode to control the implement drop, specifically comprising:

the control object corresponding to the descending speed setting knob is an implement control valve, at the moment, the controller controls the implement control valve to obtain corresponding current Ya according to the descending speed setting knob set value, meanwhile, the switch valve is controlled to be electrified, hydraulic oil output by the main pump enters a rod cavity of the suspension oil cylinder after passing through the implement control valve and the switch valve, and the hydraulic oil in a rodless cavity of the suspension oil cylinder returns to an oil tank through the switch valve.

8. The implement drop stabilization control method of claim 6, wherein the controller selects the mid/heavy load mode to control the implement drop when the load information of the suspension mechanism collected by the force sensor is greater than or equal to a set value, and specifically comprises:

the controller controls the descending valve to act, and hydraulic oil in a rodless cavity of the suspension oil cylinder returns to the oil tank through the descending valve; at the moment, the current Yb corresponding to the set value of the descending speed setting knob is the maximum current for controlling the movement process of the descending valve;

when descending and starting, the current increasing process is compensated and controlled to reduce the starting impact, and the initial current setting process is as follows:

y=kx+e （1）

wherein y represents a falling valve current value; k represents a current change coefficient; x represents time; e represents the initial normal current;

when the load information of the suspension mechanism acquired by the force sensor is greater than or equal to a set value, setting a new current setting process as follows:

y₁=k₁kx+e （2）

wherein, y₁Representing the current value after starting compensation; k is a radical of₁Represents the startup compensation factor; different load information corresponds to different compensation coefficients, and the larger the load is, the compensation coefficient k₁The smaller.

9. The implement drop stabilization control method of claim 8, wherein the controller compares a set value of the drop speed setting knob to a given speed threshold and compares a set value of the target position setting knob to a position threshold to determine a deceleration zone of the implement drop; when the implement is lowered to a specified position based on the determined deceleration interval, the lowering valve operates under control of the new current set point.

10. A tractor provided with an implement lowering stability control system as claimed in any one of claims 1 to 5.

Technical Field

The invention belongs to the technical field of tractors, and particularly relates to a method and a system for stably controlling the descending of a machine and a tractor.

Background

In the actual work of the tractor, different machines are mainly adapted to realize different field operations, and in the machine control, the tractor lifting system is used for realizing, and the front lifting system is matched with a high-end tractor by the aid of the rear lifting system of the standard matching of the tractor. As for the lifting system, there are mechanical lifting system and electrohydraulic lifting system, mainly realize the function such as rise, decline, float and stop of the machines, in the field operation, need to plow the depth control or float control, when reaching the ground, need to carry on the rise/fall control of the machines, use frequently, because the machines are heavy, in promoting the decline in-process, cause the impact problem easily, especially decline in-process, because the load is great, if the valve port opens rapidly, will cause and start the impact problem, simultaneously with the moment increase of the machines, the decline speed has acceleration process, if the machines touch the ground with the fast speed, damage the machines easily.

Disclosure of Invention

In order to solve the defects in the prior art, the invention provides a method and a system for stably controlling the descending of a machine and a tractor, which can determine the descending mode of the machine according to the load information of the machine and have the characteristics of good micro-mobility, stable starting, controllable descending speed, stable descending process and the like.

In order to achieve the purpose, the technical scheme adopted by the invention is as follows:

in a first aspect, a machine descent stabilization control system is provided, comprising: the outlet of the main pump is respectively connected with the inlet of the main overflow valve, the inlet of the fixed-difference overflow valve and the inlet of the machine tool control valve; the oil outlet of the machine tool control valve is connected with the spring cavity of the constant difference overflow valve through the steady-state throttle valve, and the oil outlet of the machine tool control valve is connected with the inlet of the switch valve; an oil outlet of the switch valve is connected with a rodless cavity of a suspension oil cylinder in the suspension mechanism; a rodless cavity of the suspension oil cylinder is simultaneously connected with an inlet of the descending valve; a rod cavity of the suspension oil cylinder is connected with an inlet of the secondary overflow valve; the position sensor, the force sensor for collecting the load information of the suspension mechanism, the descending knob, the target position setting knob and the descending speed setting knob are respectively and electrically connected with the input end of the controller; the output end of the controller is respectively and electrically connected with the electromagnetic valve of the machine tool control valve, the electromagnetic valve of the descending valve and the electromagnetic valve of the switch valve.

Further, the suspension mechanism is a three-point suspension mechanism, and the force sensor is a pin shaft type pull/pressure sensor of a lower hinge point of a lower pull rod of the three-point suspension mechanism and the tractor body.

Further, the suspension mechanism is a three-point suspension mechanism, and the force sensor is a pressure sensor arranged in a rodless cavity of the suspension oil cylinder.

Further, the suspension mechanism is a three-point suspension mechanism, and the position sensor is an angle sensor fixed on the lifting shaft.

Further, the suspension mechanism is a three-point suspension mechanism, and the position sensor is a displacement sensor for detecting the stroke of the piston of the suspension oil cylinder.

In a second aspect, a method for controlling the descending stability of a machine is provided, which uses the system for controlling the descending stability of a machine according to the first aspect, and includes: the descending knob inputs a descending instruction to the controller; the controller reads the load information of the suspension mechanism collected by the force sensor and compares the load information with a set value; when the load information of the suspension mechanism acquired by the force sensor is smaller than a set value, the controller selects a no-load or light-load mode to control the machine tool to descend; when the load information of the suspension mechanism acquired by the force sensor is larger than or equal to a set value, the controller selects a medium load/heavy load mode to control the machine tool to descend.

Further, when the load information of the suspension mechanism collected by the force sensor is smaller than a set value, the controller selects a no-load or light-load mode to control the machine tool to descend, and the method specifically comprises the following steps: the control object corresponding to the descending speed setting knob is an implement control valve, at the moment, the controller controls the implement control valve to obtain corresponding current Ya according to the descending speed setting knob set value, meanwhile, the switch valve is controlled to be electrified, hydraulic oil output by the main pump enters a rod cavity of the suspension oil cylinder after passing through the implement control valve and the switch valve, and the hydraulic oil in a rodless cavity of the suspension oil cylinder returns to an oil tank through the switch valve.

Further, when the load information of the suspension mechanism collected by the force sensor is greater than or equal to a set value, the controller selects a heavy-load mode to control the machine tool to descend, and the method specifically comprises the following steps: the controller controls the descending valve to act, and hydraulic oil in a rodless cavity of the suspension oil cylinder returns to the oil tank through the descending valve; at the moment, the current Yb corresponding to the set value of the descending speed setting knob is the maximum current for controlling the movement process of the descending valve; when descending and starting, the current increasing process is compensated and controlled to reduce the starting impact, and the initial current setting process is as follows:

y=kx+e （1）

wherein y represents a falling valve current value; k represents a current change coefficient; x represents time; e represents the initial normal current;

when the load information of the suspension mechanism acquired by the force sensor is greater than or equal to a set value, setting a new current setting process as follows:

y₁=k₁kx+e （2）

wherein, y₁Representing the current value after starting compensation; k is a radical of₁Represents the startup compensation factor; different load information corresponds to different compensation coefficients, and the larger the load is, the compensation coefficient k₁The smaller.

Further, the controller compares the set value of the descending speed setting knob with a given speed threshold value, and compares the set value of the target position setting knob with a position threshold value, so as to determine a deceleration section in which the implement descends; when the implement is lowered to a specified position based on the determined deceleration interval, the lowering valve operates under control of the new current set point.

In a third aspect, there is provided a tractor characterized by the tractor being equipped with the implement lowering stability control system of the first aspect.

Compared with the prior art, the invention has the following beneficial effects:

(1) the invention collects the load information of the machine tool by arranging the force sensor, the controller determines the descending mode of the machine tool according to the load information and controls the descending of the machine tool by combining the descending valve, the switch valve and the machine tool control valve, and the invention has the characteristics of good micro-mobility, stable starting, controllable descending speed, stable descending process and the like;

(2) the invention can realize that when the load is no load or less, the descending speed knob sets current corresponding to the machine tool control valve, and oil is fed into the rod cavity of the oil cylinder by means of the fixed-difference overflow valve, so that the required descending speed is realized, the descending speed is linearly changed according to the descending speed knob set value, and the problem of slow descending speed of no load or light load is solved;

(3) under the heavy load working condition, the invention compensates the descending starting process, reduces the starting impact and solves the starting impact problem;

(4) the invention carries out buffer control when the distance is different from the target distance in the descending process, so that the machine tool has a deceleration process when approaching the target position, the speed is stopped when reaching the target position, the stopping impact is small, the machine tool is not damaged, and the problem of stopping impact is solved;

(5) the invention carries out compensation control on the acceleration of the plough caused by the moment change in the descending process of the plough, so that the speed is approximately constant, the speed cannot be increased greatly and cannot be stopped stably, and the problem that the speed cannot be stopped stably due to the acceleration of the plough is solved.

Drawings

FIG. 1 is a schematic diagram of a system for controlling a machine descent stability according to an embodiment of the present disclosure;

fig. 2 is a schematic control flow diagram of a method for controlling a machine descent stability according to an embodiment of the present invention.

Detailed Description

The invention is further described below with reference to the accompanying drawings. The following examples are only for illustrating the technical solutions of the present invention more clearly, and the protection scope of the present invention is not limited thereby.

The first embodiment is as follows:

as shown in fig. 1, a machine descent stabilization control system includes: the main pump 2 is driven by the engine 1, the inlet of the main pump 1 is communicated with an oil tank, and the outlet of the main pump 1 is respectively communicated with the inlet of the main overflow valve 3, the inlet of the fixed-difference overflow valve 5 and the inlet of the machine tool control valve 6; the outlet of the main overflow valve 3 and the outlet of the constant-difference overflow valve 5 are communicated with an oil tank; the oil return port is communicated with the oil tank when the machine tool control valve 6 is in a normal position; the oil outlet of the machine tool control valve 6 is connected with the spring cavity of the constant difference overflow valve 5 through the steady-state throttle valve 4, and the oil outlet of the machine tool control valve 6 is communicated with the inlet of the switch valve 8; an oil outlet of the switch valve 8 is connected with a rodless cavity of a suspension oil cylinder 9 in the suspension mechanism; the rodless cavity of the suspension oil cylinder 9 is simultaneously communicated with the inlet of the descending valve 7; the outlet of the descending valve 7 is communicated with the oil tank; a rod cavity of the suspension oil cylinder 9 is communicated with an inlet of a secondary overflow valve 10; the outlet of the secondary overflow valve 10 is communicated with the oil tank; the position sensor 12, the force sensor 11 for collecting the load information of the suspension mechanism, the descending knob 16, the target position setting knob 15 and the descending speed setting knob 14 are respectively and electrically connected with the input end of the controller 13; the output end of the controller 13 is respectively electrically connected with the electromagnetic valve of the machine tool control valve 6, the electromagnetic valve of the descending valve 7 and the electromagnetic valve of the switch valve 8.

In this embodiment, the suspension mechanism is a three-point suspension mechanism, and the force sensor 11 is a pin-type pull/pressure sensor at a lower hinge point between a lower pull rod of the three-point suspension mechanism and the tractor body, or a pressure sensor installed in a rodless cavity of the suspension cylinder, or a rate of change of the deceleration over a period of time is tested, so that the judgment of the load condition can be realized. This embodiment adopts position sensor, acquires the real-time position of machines, and this position sensor can be for fixing the angle sensor on the lift shaft, also can all turn into the actual position of machines for the displacement sensor who is used for detecting the piston stroke of suspension cylinder.

The load information of machines is gathered through setting up force sensor to this embodiment, and the decline mode of machines is confirmed according to load information to the controller to combine descending valve, ooff valve and machines control valve decline, have characteristics such as micro-mobility is good, start steadily, descending speed is controllable, the decline process is steady.

Example two:

as shown in fig. 1 and fig. 2, based on a machine descending stability control system according to a first embodiment, the present embodiment provides a machine descending stability control method, which adopts the machine descending stability control system according to the first embodiment, and includes: the descending knob inputs a descending instruction to the controller; the controller reads the load information of the suspension mechanism collected by the force sensor and compares the load information with a set value; when the load information of the suspension mechanism acquired by the force sensor is smaller than a set value, the controller selects a no-load or light-load mode to control the machine tool to descend; when the load information of the suspension mechanism acquired by the force sensor is larger than or equal to a set value, the controller selects a medium load/heavy load mode to control the machine tool to descend.

When the load information of the suspension mechanism collected by the force sensor is smaller than a set value, the controller selects a no-load or light-load mode to control the machine tool to descend, and the method specifically comprises the following steps: the control object corresponding to the descending speed setting knob is an implement control valve, at the moment, the controller controls the implement control valve to obtain corresponding current Ya according to the descending speed setting knob set value, meanwhile, the switch valve is controlled to be electrified, hydraulic oil output by the main pump enters a rod cavity of the suspension oil cylinder after passing through the implement control valve and the switch valve, and the hydraulic oil in a rodless cavity of the suspension oil cylinder returns to an oil tank through the switch valve.

When the load information of the suspension mechanism that force sensor gathered is more than or equal to the setting value, the controller selects heavy load mode control machines and tools to descend, specifically includes: the controller controls the descending valve to act, and hydraulic oil in a rodless cavity of the suspension oil cylinder returns to the oil tank through the descending valve; at the moment, the current Yb corresponding to the set value of the descending speed setting knob is the maximum current for controlling the movement process of the descending valve; when descending and starting, the current increasing process is compensated and controlled to reduce the starting impact, and the initial current setting process is as follows:

y=kx+e （1）

wherein y represents a falling valve current value; k represents a current change coefficient; x represents time; e represents the initial normal current;

when the load information of the suspension mechanism acquired by the force sensor is greater than or equal to a set value, setting a new current setting process as follows:

y₁=k₁kx+e （2）

wherein, y₁Representing the current value after starting compensation; k is a radical of₁Represents the startup compensation factor; different load information corresponds to different compensation coefficients, and the larger the load is, the compensation coefficient k₁The smaller.

The controller compares the set value of the descending speed setting knob with a given speed threshold value, and compares the set value of the target position setting knob with a position threshold value, so as to determine a descending speed reduction interval of the machine tool; when the implement is lowered to a specified position based on the determined deceleration interval, the lowering valve operates under control of the new current set point.

The specific working mode is as follows:

when the operator operates through the descending knob on the control panel to carry out the three-point suspension descending action, the force sensor 11 judges whether the three-point suspension mechanism has machines or machine load information according to the load information of the three-point suspension mechanism:

when load information is collected according to the force sensor 11, if the pressure value of the force sensor is less than nKN, the controller 13 judges that no machine tool is available or the self weight of the machine tool is light at the moment, the control object corresponding to the descending speed setting knob 14 is the machine tool control valve 6 at the moment, the controller 13 sets the knob setting value according to the descending speed to control the machine tool control valve 6 to obtain corresponding current Ya so as to open the corresponding opening, and simultaneously controls the switch valve 8 to obtain electricity so as to realize the left position action, the hydraulic oil output by the main pump 2 enters the rod cavity of the suspension oil cylinder 9 after passing through the left position of the machine tool control valve 6 and the left position of the switch valve 8, the hydraulic oil in the rodless cavity of the suspension oil cylinder 9 returns to the oil tank through the left position of the switch valve 8, at the moment, because the self three-point suspension mechanism and the self weight of the smaller machine tool are smaller, the front-back pressure difference of the machine tool control valve 6 is approximate to a fixed value, the descending speed of the suspension oil cylinder 9 is positively correlated with the opening of the machine tool control valve 6, i.e., positively correlated with the set value of the descent speed setting knob 14.

When the load information collected by the force sensor 11 is not less than nKN, the controller 13 judges that the machine is under medium/heavy load, the controller 13 controls the action of the descending valve 7, the hydraulic oil in the rodless cavity of the suspension oil cylinder 9 passes through the left oil return tank of the descending valve 7, the current Yb corresponding to the set value of the descending speed setting knob 14 is the maximum current for controlling the movement process of the descending valve 7, the opening degree of the descending valve 7 and the pressure difference between the inlet and the outlet of the descending valve determine the descending speed, at the moment, the current is increased quickly in the starting process, starting impact is easy to generate, the descending process is easy to accelerate, if speed compensation is not performed, the machine impacts the ground at a higher speed, and the machine is easy to damage.

When descending and starting, the current increasing process needs to be compensated and controlled to reduce the starting impact, and the initial current setting process is as follows:

y=kx+e （1）

wherein y represents a falling valve current value; k represents a current change coefficient; x represents time; e represents the initial normal current;

when the load information of the suspension mechanism acquired by the force sensor is greater than or equal to a set value, setting a new current setting process as follows:

y₁=k₁kx+e （2）

wherein, y₁Representing the current value after starting compensation; k is a radical of₁Represents the startup compensation factor; different load information corresponds to different compensation coefficients, and the larger the load is, the compensation coefficient k₁The smaller.

Further, the controller judges the set value a of the lowering speed setting knob 14:

when a is larger than or equal to a1 (a 1 represents a first speed threshold), further judging the set value b of the target position setting knob 15, and when b is larger than or equal to b1 (b 1 represents a first position threshold), setting the deceleration interval to c1, namely, the controller 13 controls the descending valve 7 to descend to a b + c1 position, and starting deceleration control (namely, the descending valve 7 works under the control of a new current set value); when b is less than b1, setting the deceleration interval as c2, namely, the controller controls the descending valve 7 to descend to a b + c2 position, and starting deceleration control;

when a2 is more than a and less than a1 (a 2 represents a second speed threshold), further judging a position knob set value b, and when b is more than or equal to b1, setting a deceleration interval as c3, namely, the controller 13 controls the descending valve 7 to descend to a b + c3 position to start deceleration control; when b is less than b1, setting the deceleration interval as c4, namely the controller 13 controls the descending valve 7 to descend to the b + c4 position to start deceleration control;

when a is less than or equal to a2, the lowering speed of the machine tool is set according to the setting value of the lowering speed knob because the setting value of the lowering speed knob is smaller, the controller 13 directly gives the corresponding current of the lowering valve 7, and the deceleration control is not needed any more.

Further, the controller 13 determines the distance d between the current position (feedback information from the position sensor 12) and the position (control panel setting) set by the target position setting knob 15:

when d is greater than c (c represents the calculation of the set value of the current speed knob and the start value of the deceleration interval corresponding to the set value of the target distance knob), that is, the controller 13 judges that the distance between the current machine tool position and the target position exceeds the set deceleration interval, the controller 13 sets the set value of the knob 14 according to the deceleration speed, and gives the corresponding current value, but as the machine tool descends, the speed is faster and faster due to the increase of the moment of the machine tool and the same opening, and at this time, the given current is compensated:

y₂=Yb-k₂x （3）

wherein, y₂Indicating the current after torque increase compensation, Yb indicating the current value corresponding to the set value of the descending speed setting knob under medium/heavy load conditions, k₂Increasing the compensation coefficient for the moment;

further, when d < c, namely the current actual position of the machine tool is already in a preset deceleration interval, the maximum current of the machine tool is limited when the machine tool is started, and at the moment, the current is not given according to the set value of the descending speed knob any more, and the given current is limited:

y₃=k₃Yb-k₄x （4）

wherein, y₃Indicates the process setting current, k, in the small deceleration interval₃Taking the value in the interval (0.5,1) when the deceleration interval is small, wherein the closer the actual position is to the target position, the k₃The smaller, k₄A compensation coefficient is set for the small deceleration interval; and starts to decelerate as the real-time position approaches the set target position, y₃After the speed is reduced to a certain value, the reducing speed is also reduced to 0;

further, when the tool reaches d = c in the descending process of the tool, the deceleration interval is entered,

y₄=y₂-k₅x（5）

wherein, y₄Indicates the process setting current, k, of the full deceleration interval₅Representing a compensation coefficient of a full deceleration interval; the current decreases approximately linearly until the target distance, y, is reached₄When the speed of the descending rod decreases to a certain value, the descending speed also decreases to 0.

The invention can realize that when the load is no load or less, the set value of the descending speed knob corresponds to the machine tool control valve, and the oil enters the rod cavity of the oil cylinder by combining the fixed-difference overflow valve, thereby realizing the required descending speed, and the descending speed is linear change, thereby solving the problem of lower descending speed when the load is no load or light load.

In the embodiment, under the heavy-load working condition, the descending starting process is compensated, the starting impact is reduced, and the starting impact problem is solved; the buffer control is carried out when the distance between the machines and tools is different in the descending process and the target distance is different, so that the speed reduction process is carried out when the machines and tools are close to the target position, the speed is stopped when the machines and tools reach the target position, the stopping impact is small, the machines and tools are not damaged, and the problem of stopping impact is solved; in the process of the decline of the plough, the machine is accelerated due to the change of the moment, compensation control is carried out, the speed is approximately constant, the speed cannot be increased greatly, the machine cannot be stopped stably, and the problem that the speed cannot be stopped stably due to the acceleration of the speed is solved.

Example three:

based on the system and the method for stably controlling the descending of the machine described in the first embodiment, the present embodiment provides a tractor equipped with the system and the method for stably controlling the descending of the machine described in the first embodiment

The above description is only a preferred embodiment of the present invention, and it should be noted that, for those skilled in the art, several modifications and variations can be made without departing from the technical principle of the present invention, and these modifications and variations should also be regarded as the protection scope of the present invention.