CN115030246B

CN115030246B - Positive flow excavator, control method, control device and controller thereof

Info

Publication number: CN115030246B
Application number: CN202210565260.8A
Authority: CN
Inventors: 高见厂; 袁野; 吴元峰; 魏学平; 岳宝根; 狄祥
Original assignee: Zoomlion Earth Moving Machinery Co Ltd; Shaanxi Zoomlion West Earthmoving Machinery Co Ltd
Current assignee: Zoomlion Earth Moving Machinery Co Ltd; Shaanxi Zoomlion West Earthmoving Machinery Co Ltd
Priority date: 2022-05-23
Filing date: 2022-05-23
Publication date: 2024-01-16
Anticipated expiration: 2042-05-23
Also published as: WO2023226289A1; CN115030246A

Abstract

The embodiment of the invention provides a positive flow excavator, a control method, a control device and a controller thereof, wherein the control method for the positive flow excavator comprises the following steps: acquiring the pilot pressure of the bucket rod adduction of the positive flow excavator; determining the action type of the positive flow excavator; under the condition that the action type is a preset action type, determining the maximum secondary pressure allowed by the bucket rod adduction electromagnetic valve, and determining the control current of the bucket rod adduction electromagnetic valve according to the maximum secondary pressure and the bucket rod adduction pilot pressure; determining the control current of the bucket rod adduction electromagnetic valve according to the bucket rod adduction pilot pressure under the condition that the action type is not the preset action type; and outputting control current to the bucket rod adduction electromagnetic valve so as to control the bucket rod adduction speed. According to the embodiment of the invention, different control strategies can be set for the valve core of the bucket rod according to different actions and different loads, so that the land leveling performance of the positive flow excavator during land leveling operation is improved, and meanwhile, the oil consumption and the operation efficiency during excavating operation are both considered.

Description

Positive flow excavator, control method, control device and controller thereof

Technical Field

The invention relates to the technical field of excavator control, in particular to a positive flow excavator, a control method, a control device and a controller thereof.

Background

The excavator realizes the land leveling action by lifting the movable arm (oil inlet of a large cavity of the movable arm) and adding the recovery bucket rod (oil inlet of a small cavity of the bucket rod), and because the movable arm is lifted to overcome the gravity to do work, the pressure of the large cavity of the movable arm is higher than that of the small cavity of the bucket rod, in order to ensure the operability of the land leveling operation, a movable arm priority logic valve is generally added, and when the movable arm and the bucket rod simultaneously act, the movable arm priority logic valve limits the opening of a valve core of the bucket rod, so that the lifting speed of the movable arm is ensured. However, when the excavator performs other actions such as excavating, the movable arm priority logic valve still works, so that throttling loss is caused, and the working efficiency and the fuel efficiency of the whole excavator are affected. Therefore, there is an urgent need to propose a technical solution to solve the above technical problems in the prior art.

Disclosure of Invention

The embodiment of the invention aims to provide a positive flow excavator, a control method, a control device and a controller thereof, which solve the technical problems in the prior art.

In order to achieve the above object, a first aspect of the present invention provides a control method for a positive flow excavator including an arm, a boom, a bucket, and an arm adduction solenoid valve, the control method comprising: acquiring the pilot pressure of the bucket rod adduction of the positive flow excavator; determining the action type of the positive flow excavator; under the condition that the action type is a preset action type, determining the maximum secondary pressure allowed by the bucket rod adduction electromagnetic valve, and determining the control current of the bucket rod adduction electromagnetic valve according to the maximum secondary pressure and the bucket rod adduction pilot pressure; determining the control current of the bucket rod adduction electromagnetic valve according to the bucket rod adduction pilot pressure under the condition that the action type is not the preset action type; outputting control current to an bucket rod adduction electromagnetic valve so as to control the adduction speed of the bucket rod; wherein the preset action type comprises one or more of the following: the bucket rod receives the bill in; a land leveling action; and (3) an arm retraction arm lifting bucket retraction compound action.

In an embodiment of the present invention, the positive flow excavator further includes a turntable, and determining the action type of the positive flow excavator includes: acquiring the bucket rod outward swing pilot pressure, the rotary pilot pressure, the movable arm lifting pilot pressure, the movable arm descending pilot pressure, the bucket adduction pilot pressure and the bucket outward swing pilot pressure of the positive flow excavator; determining that the action type is a bucket arm adduction action under the condition that the bucket arm adduction pilot pressure is greater than or equal to a preset opening pressure, and the bucket arm outswing pilot pressure, the rotary pilot pressure, the movable arm lifting pilot pressure, the movable arm descending pilot pressure, the bucket adduction pilot pressure and the bucket outswing pilot pressure are all smaller than the preset opening pressure; determining that the action type is a land leveling action under the condition that the bucket arm adduction pilot pressure and the boom lifting pilot pressure are both greater than or equal to a preset opening pressure and the bucket arm outswing pilot pressure, the swing pilot pressure, the boom lowering pilot pressure, the bucket adduction pilot pressure and the bucket outswing pilot pressure are both less than the preset opening pressure; and determining that the action type is a bucket adduction composite action of the boom adduction boom lifting bucket under the condition that the boom adduction pilot pressure, the boom lifting pilot pressure and the bucket adduction pilot pressure are all greater than or equal to a preset opening pressure and the boom outswing pilot pressure, the rotary pilot pressure, the boom descending pilot pressure and the bucket outswing pilot pressure are all less than the preset opening pressure.

In an embodiment of the present invention, the positive flow excavator further includes a first main pump and a second main pump, and determining the maximum secondary pressure allowed by the arm adduction solenoid valve includes: under the condition that the action type is the bucket rod internal order receiving action, acquiring the pressure of the first main pump and the pressure of the second main pump; determining a maximum secondary pressure based on the pressure of the first primary pump and the pressure of the second primary pump; determining a stage type of the land leveling action when the action type is the land leveling action; determining a maximum secondary pressure according to the stage type; under the condition that the action type is the combined action of bucket arm retraction, movable arm lifting and bucket retraction, the movable arm lifting pilot pressure and bucket retraction pilot pressure of the positive flow excavator are obtained; determining a maximum secondary pressure according to the boom lifting pilot pressure and the bucket adduction pilot pressure; wherein the phase type is selected from any one of a start phase, an intermediate phase and an end phase.

In an embodiment of the present invention, determining the maximum secondary pressure from the pressure of the first primary pump and the pressure of the second primary pump includes: determining an average of the pressure of the first main pump and the pressure of the second main pump; and determining a maximum secondary pressure from the average value.

In an embodiment of the present invention, determining the maximum secondary pressure according to the average value includes: the maximum secondary pressure is determined according to the following formula:

wherein set_arminopilot_max is the maximum secondary pressure, aver_pp1and Pp2 is the average value, set_arminopilot_max1 is the first preset maximum secondary pressure, set_arminopilot_max2 is the second preset maximum secondary pressure, pp1 is the first preset main pump pressure, and Pp2 is the second preset main pump pressure.

In an embodiment of the present invention, determining the stage type of the land leveling action includes: determining that the stage type is an ending stage when the pressure of the first main pump and the pressure of the second main pump are both greater than or equal to the third preset main pump pressure; under the condition that the pressure of the first main pump and the pressure of the second main pump are smaller than the third preset main pump pressure, determining whether the bucket rod adduction pilot pressure is larger than or equal to the preset full-opening pressure and determining whether the movable arm lifting pilot pressure is larger than or equal to the preset full-opening pressure; under the condition that the movable arm lifting pilot pressure and the bucket rod adduction pilot pressure are both larger than or equal to the preset full-opening pressure, determining the stage type as an initial stage; and determining the stage type as the intermediate stage when it is determined that the boom lifting pilot pressure is less than the preset full-opening pressure and the arm adduction pilot pressure is greater than or equal to the preset full-opening pressure.

In an embodiment of the present invention, determining the maximum secondary pressure according to the stage type includes: under the condition that the stage type is an initial stage, determining that the maximum secondary pressure is a third preset maximum secondary pressure; determining a maximum secondary pressure according to the boom lifting pilot pressure in the case of the stage type being an intermediate stage; and determining a maximum secondary pressure based on the pressure of the first main pump and the pressure of the second main pump in the case that the stage type is an end stage.

In an embodiment of the present invention, the positive flow excavator further includes a first boom spool, and determining the maximum secondary pressure according to the boom lifting pilot pressure includes: the maximum secondary pressure is determined according to the following formula:

the set_arminopilot_max is the maximum secondary pressure, pilot_boom is the boom lifting Pilot pressure, set_arminopilot_max1 is the first preset maximum secondary pressure, set_arminopilot_max3 is the third preset maximum secondary pressure, pbu1 is the minimum secondary pressure required when the first boom spool is opened, and Pbu2 is the minimum secondary pressure required when the first boom spool is fully opened.

In an embodiment of the present invention, determining a maximum secondary pressure from a boom-up pilot pressure and a bucket adduction pilot pressure includes: determining a maximum value of the boom lifting pilot pressure and the bucket adduction pilot pressure; and determining a maximum secondary pressure based on the maximum value.

In an embodiment of the present invention, determining the maximum secondary pressure according to the maximum value includes: the maximum secondary pressure is determined according to the following formula:

wherein set_arminopilot_max is the maximum secondary pressure, buandapilot_max is the maximum, set_arminopilot_max1 is the first preset maximum secondary pressure, set_arminopilot_max4 is the fourth preset maximum secondary pressure, pba1 is the first preset pressure, and pba2 is the second preset pressure.

In the embodiment of the invention, determining the control current of the arm adduction electromagnetic valve according to the maximum secondary pressure and the arm adduction pilot pressure comprises: determining a control current of the bucket rod adduction electromagnetic valve according to the bucket rod adduction pilot pressure under the condition that the bucket rod adduction pilot pressure is less than or equal to the maximum secondary pressure; and determining the control current of the bucket rod adduction electromagnetic valve according to the maximum secondary pressure under the condition that the bucket rod adduction pilot pressure is greater than the maximum secondary pressure.

In an embodiment of the present invention, the positive flow excavator further includes a first arm spool, and determining a control current of the arm adduction electromagnetic valve according to the arm adduction pilot pressure includes: the control current is determined according to the following formula:

the set_current is control Current, pilot_armin is Pilot pressure of the bucket rod adduction, pilot_min is minimum secondary pressure required when the first bucket rod valve element is opened, pilot_max is minimum secondary pressure required when the first bucket rod valve element is fully opened, current_max is the upper limit value of the value range of the control Current, and current_min is the lower limit value of the value range of the control Current.

In the embodiment of the invention, determining the control current of the arm adduction electromagnetic valve according to the maximum secondary pressure comprises the following steps: the control current is determined according to the following formula:

the set_current is the control Current, set_arminpilot_max is the maximum secondary pressure, pilot_min is the minimum secondary pressure required when the first arm valve element is opened, pilot_max is the minimum secondary pressure required when the first arm valve element is fully opened, current_max is the upper limit value of the value range of the control Current, and current_min is the lower limit value of the value range of the control Current.

A second aspect of the present invention provides a controller configured to perform the control method for a positive flow excavator of the foregoing embodiments.

A third aspect of the present invention provides a control device for a positive-flow excavator including a boom, an arm adduction solenoid valve, a turntable, a bucket, a first boom spool, a first arm spool, a first main pump, and a second main pump, the control device comprising: an arm adduction pilot pressure sensor configured to detect an arm adduction pilot pressure; a boom out-swing pilot pressure sensor configured to detect a boom out-swing pilot pressure; a rotary pilot pressure sensor configured to detect a rotary pilot pressure; a boom-up pilot pressure sensor configured to detect a boom-up pilot pressure; a boom-down pilot pressure sensor configured to detect a boom-down pilot pressure; a bucket adduction pilot pressure sensor configured to detect bucket adduction pilot pressure; a bucket outer swing pilot pressure sensor configured to detect bucket outer swing pilot pressure; a first main pump pressure sensor configured to detect a pressure of the first main pump; a second main pump pressure sensor configured to detect a pressure of the second main pump; and the controller of the foregoing embodiment.

A fourth aspect of the present invention provides a positive flow excavator, comprising: a movable arm; a bucket rod; an electromagnetic valve is retracted in the bucket rod; a turntable; a bucket; a first boom spool; a first stick spool; a first main pump; a second main pump; and the control device for the positive flow excavator of the foregoing embodiment.

According to the embodiment of the invention, through the technical scheme, the land leveling performance of the positive flow excavator during land leveling operation can be improved, and meanwhile, the oil consumption and the operation efficiency during excavating operation are both considered.

Additional features and advantages of embodiments of the invention will be set forth in the detailed description which follows.

Drawings

The accompanying drawings are included to provide a further understanding of embodiments of the invention and are incorporated in and constitute a part of this specification, illustrate embodiments of the invention and together with the description serve to explain, without limitation, the embodiments of the invention. In the drawings:

FIG. 1 is a flow diagram of a control method 100 for a positive flow excavator in accordance with an embodiment of the present invention;

fig. 2 is a schematic structural view of a control device 200 for a positive flow excavator according to an embodiment of the present invention;

FIG. 3 is a schematic diagram of a positive flow excavator 300 according to an embodiment of the present invention;

FIG. 4 is a schematic diagram of an exemplary positive flow excavator control system based on stick control of the present invention;

FIG. 5 is a flow chart of an exemplary positive flow excavator control method based on stick control of the present invention;

FIG. 6 is a schematic diagram of an exemplary stick in-take-up action determination signal sequence in accordance with the present invention;

FIG. 7 is a timing diagram of an exemplary land leveling action determination signal according to the present invention;

FIG. 8 is a timing diagram of a three-action composite determination signal according to an embodiment of the present invention

FIG. 9 is a schematic diagram of a correspondence between control current of an arm adduction solenoid valve and an arm adduction pilot pressure in accordance with an example of the present invention;

FIG. 10 is a schematic diagram of the maximum secondary pressure allowed by the stick retraction solenoid of the present example versus the average pressure of the main pump 205 and the main pump 206;

FIG. 11 is a schematic illustration of an exemplary land-leveling motion trajectory of the present invention;

FIG. 12 is a schematic diagram of a relationship between maximum secondary pressure allowed by an arm adduction solenoid and boom boost pilot pressure in accordance with an example of the present invention; and

fig. 13 is a schematic diagram of a relationship between the maximum secondary pressure allowed by the arm adduction solenoid valve and the maximum of both the boom-up pilot pressure and the bucket adduction pilot pressure, which is an example of the present invention.

Detailed Description

The following describes the detailed implementation of the embodiments of the present invention with reference to the drawings. It should be understood that the detailed description and specific examples, while indicating and illustrating the invention, are not intended to limit the invention.

In the present embodiment, if directional indications (such as up, down, left, right, front, and rear … …) are included, the directional indications are merely used to explain the relative positional relationship, movement, and the like between the components in a specific posture (as shown in the drawings), and if the specific posture is changed, the directional indications are correspondingly changed.

In addition, if there is a description of "first", "second", etc. in the embodiments of the present application, the description of "first", "second", etc. is for descriptive purposes only and is not to be construed as indicating or implying a relative importance or implicitly indicating the number of technical features indicated. Thus, a feature defining "a first" or "a second" may explicitly or implicitly include at least one such feature. In addition, the technical solutions of the embodiments may be combined with each other, but it is necessary to base that the technical solutions can be realized by those skilled in the art, and when the technical solutions are contradictory or cannot be realized, the combination of the technical solutions should be considered to be absent and not within the protection scope of the present application.

As shown in fig. 1, in an embodiment of the present invention, there is provided a control method 100 for a positive-flow excavator including a stick, a boom, a bucket, and a stick-in solenoid valve, the control method 100 for the positive-flow excavator including the steps of:

step S110: and acquiring the pilot pressure of the bucket rod adduction of the positive flow excavator.

Step S120: the action type of the positive flow excavator is determined.

Step S130: and under the condition that the action type is the preset action type, determining the maximum secondary pressure allowed by the bucket rod adduction electromagnetic valve, and determining the control current of the bucket rod adduction electromagnetic valve according to the maximum secondary pressure and the bucket rod adduction pilot pressure.

Step S140: and when the action type is not the preset action type, determining the control current of the bucket rod adduction electromagnetic valve according to the bucket rod adduction pilot pressure. And

Step S150: and outputting the control current to the bucket rod adduction electromagnetic valve so as to control the adduction speed of the bucket rod.

Wherein the preset action type comprises one or more of the following for example:

the bucket rod receives the bill in;

a land leveling action; and

and the bucket rod adduction movable arm lifts the bucket adduction compound action. The arm retraction boom hoist bucket retraction compound action is also referred to as a three action compound.

Further, the positive flow excavator also includes a turntable, for example. Accordingly, determining the action type of the positive flow excavator, i.e. step S120, for example, includes:

(a1) The method comprises the steps of obtaining the bucket rod outward swing pilot pressure, the rotary pilot pressure, the movable arm lifting pilot pressure, the movable arm descending pilot pressure, the bucket adduction pilot pressure and the bucket outward swing pilot pressure of the positive flow excavator.

(a2) And determining that the action type is the bucket arm adduction action under the condition that the bucket arm adduction pilot pressure is greater than or equal to a preset opening pressure, and the bucket arm outswing pilot pressure, the rotary pilot pressure, the movable arm lifting pilot pressure, the movable arm descending pilot pressure, the bucket adduction pilot pressure and the bucket outswing pilot pressure are all smaller than the preset opening pressure.

(a3) And determining that the action type is a land leveling action under the condition that the bucket arm adduction pilot pressure and the movable arm lifting pilot pressure are both greater than or equal to a preset opening pressure and the bucket arm outswing pilot pressure, the rotary pilot pressure, the movable arm descending pilot pressure, the bucket adduction pilot pressure and the bucket outswing pilot pressure are both less than the preset opening pressure. And

(a4) And determining that the action type is the bucket adduction composite action of the bucket adduction arm lifting arm under the condition that the bucket adduction pilot pressure, the movable arm lifting pilot pressure and the bucket adduction pilot pressure are all greater than or equal to a preset opening pressure and the bucket outswing pilot pressure, the rotary pilot pressure, the movable arm descending pilot pressure and the bucket outswing pilot pressure are all smaller than the preset opening pressure.

Specifically, the preset opening pressure may have a value ranging from 5bar to 7bar, for example, and may have a value of 5bar, for example.

Further, the positive flow excavator further includes, for example, a first main pump and a second main pump. Accordingly, the determining of the maximum secondary pressure allowed by the arm adduction solenoid in step S130 includes, for example, the steps of:

(b1) And under the condition that the action type is the bucket rod internal receipt action, acquiring the pressure of the first main pump and the pressure of the second main pump.

(b2) The maximum secondary pressure is determined based on the pressure of the first primary pump and the pressure of the second primary pump.

(b3) In the case where the action type is a level action, a stage type of the level action is determined.

(b4) The maximum secondary pressure is determined according to the stage type.

(b5) When the operation type is a combined operation of arm retraction and arm lifting bucket retraction, the arm lifting pilot pressure and the bucket retraction pilot pressure of the positive flow excavator are obtained. And

(b6) And determining the maximum secondary pressure according to the movable arm lifting pilot pressure and the bucket adduction pilot pressure.

Wherein the phase type is selected from any one of a start phase, an intermediate phase and an end phase, for example.

Specifically, the maximum secondary pressure is determined from the pressure of the first main pump and the pressure of the second main pump, i.e. step (b 2) comprises, for example, the steps of:

(b21) An average of the pressures of the first and second main pumps is determined. And

(b22) The maximum secondary pressure is determined from the average value.

Specifically, the maximum secondary pressure is determined from the average value, i.e. step (b 22) comprises, for example:

the maximum secondary pressure is determined according to the following formula:

Specifically, the first preset maximum secondary pressure may have a value ranging from 20bar to 25bar, for example, and may have a value of 25bar, for example. The second preset maximum secondary pressure may have a value ranging from 35bar to 40bar, for example, and may have a value of 40bar, for example. The first preset main pump pressure is, for example, 15Mpa to 20Mpa, specifically 15Mpa. The second preset main pump pressure is, for example, 25Mpa to 30Mpa, and specifically, 25Mpa.

In particular, determining the phase type of the grading action, i.e. step (b 3) comprises, for example:

(b31) And determining that the stage type is an ending stage when the pressure of the first main pump and the pressure of the second main pump are both greater than or equal to the third preset main pump pressure.

(b32) And under the condition that the pressure of the first main pump and the pressure of the second main pump are smaller than the third preset main pump pressure, determining whether the bucket rod adduction pilot pressure is larger than or equal to the preset full-opening pressure and determining whether the movable arm lifting pilot pressure is larger than or equal to the preset full-opening pressure.

(b33) And under the condition that the boom lifting pilot pressure and the arm adduction pilot pressure are both larger than or equal to the preset full-opening pressure, determining the stage type as an initial stage. And

(b34) And determining that the stage type is an intermediate stage when the boom lifting pilot pressure is determined to be smaller than the preset full-opening pressure and the arm adduction pilot pressure is determined to be greater than or equal to the preset full-opening pressure.

Specifically, the third preset main pump pressure is, for example, 15Mpa to 20Mpa, and specifically, 15Mpa. The preset full-open pressure may have a value ranging from 20bar to 25bar, for example, and may have a value of 25bar, for example.

Specifically, the maximum secondary pressure is determined according to the stage type, i.e. step (b 4) comprises, for example:

(b41) In case the phase type is the initial phase, the maximum secondary pressure is determined as the third preset maximum secondary pressure.

(b42) In the case where the stage type is the intermediate stage, the maximum secondary pressure is determined from the boom-up pilot pressure. And

(b43) In case the phase type is an end phase, the maximum secondary pressure is determined from the pressure of the first main pump and the pressure of the second main pump.

Further, the positive flow excavator, for example, further includes a first boom spool. Accordingly, determining the maximum secondary pressure from the boom-up pilot pressure, i.e., step (b 42), for example, includes:

Specifically, the first preset maximum secondary pressure may have a value ranging from 20bar to 25bar, for example, and may have a value of 25bar, for example. The third preset maximum secondary pressure may have a value in the range of, for example, 10bar to 15bar, specifically, 12bar. The minimum secondary pressure required for opening the first boom spool may range, for example, from 5bar to 7bar, and may be, for example, 5bar. The minimum secondary pressure required when the first boom spool is fully open may range, for example, from 20bar to 25bar, and may be, for example, 25bar.

Specifically, the maximum secondary pressure is determined from the boom-up pilot pressure and the bucket adduction pilot pressure, that is, step (b 6) includes, for example, the steps of:

(b61) A maximum value of the boom-up pilot pressure and the bucket adduction pilot pressure is determined. And

(b62) The maximum secondary pressure is determined from the maximum value.

Specifically, the maximum secondary pressure is determined from the maximum value, i.e. step (b 62) comprises, for example:

Specifically, the first preset maximum secondary pressure has a value ranging, for example, from 20bar to 25bar, and specifically, for example, a value of 25bar. The fourth preset maximum secondary pressure has a value in the range of, for example, 10bar to 15bar, specifically, for example, 12bar. The first preset pressure has a value in the range of, for example, 5bar to 7bar, in particular, for example, 5bar. The second preset pressure has a value in the range of, for example, 20bar to 25bar, in particular, for example, 25bar.

Specifically, determining the control current of the arm adduction solenoid valve in step S130 based on the maximum secondary pressure and the arm adduction pilot pressure includes, for example, the steps of:

(c1) When the arm adduction pilot pressure is less than or equal to the maximum secondary pressure, a control current of the arm adduction electromagnetic valve is determined according to the arm adduction pilot pressure. And

(c2) And under the condition that the pilot pressure in the bucket rod is larger than the maximum secondary pressure, determining the control current of the bucket rod adduction electromagnetic valve according to the maximum secondary pressure.

Further, the positive flow excavator further includes, for example, a first arm spool, and the control current of the arm adduction solenoid valve is determined according to the arm adduction pilot pressure, that is, step S140 includes, for example:

the control current is determined according to the following formula:

Specifically, determining the control current of the arm adduction solenoid valve according to the maximum secondary pressure, that is, step (c 2) includes, for example:

The control current is determined according to the following formula:

Specifically, the minimum secondary pressure required when the first arm spool is opened may range from, for example, 5bar to 7bar, and specifically, for example, 5bar. The minimum secondary pressure required when the first arm spool is fully open may range, for example, from 20bar to 25bar, and specifically, for example, may range from 25bar. The upper limit value of the control current is, for example, 600mA to 800mA, and specifically, 800mA. The lower limit value of the control current is, for example, 200mA to 400mA, and specifically, 250mA.

In an embodiment of the present invention, a controller is provided, for example, configured to perform the control method 100 for a positive flow excavator according to any of the previous embodiments.

The specific functions and details of the control method 100 for the positive flow excavator may refer to the related descriptions of the foregoing embodiments, and are not repeated herein.

Specifically, the controller may be, for example, a control device such as an industrial personal computer, an embedded system, a microprocessor, and a programmable logic device.

More specifically, the controller is, for example, a vehicle control unit of a positive flow excavator.

As shown in fig. 2, in an embodiment of the present invention, there is provided a control apparatus 200 for a positive-flow excavator including a boom, an arm adduction solenoid valve, a turn table, a bucket, a first boom spool, a first arm spool, a first main pump, and a second main pump, the control apparatus 200 for a positive-flow excavator including: controller 210, arm adduction pilot pressure sensor 220, arm outswing pilot pressure sensor 230, swing pilot pressure sensor 240, boom lifting pilot pressure sensor 250, boom lowering pilot pressure sensor 260, bucket adduction pilot pressure sensor 270, bucket outswing pilot pressure sensor 280, first main pump pressure sensor 291, and second main pump pressure sensor 292.

Wherein the controller 210 is, for example, a controller according to any of the previous embodiments. The specific functions and details of the controller 210 may be referred to the related descriptions of the foregoing embodiments, and will not be repeated herein.

The arm adduction pilot pressure sensor 220 is configured to detect an arm adduction pilot pressure, for example.

The arm swing-out pilot pressure sensor 230 is configured to detect, for example, an arm swing-out pilot pressure.

The swing pilot pressure sensor 240 is configured to detect a swing pilot pressure, for example.

Boom-up pilot pressure sensor 250 is configured to detect a boom-up pilot pressure, for example.

The boom-down pilot pressure sensor 260 is configured to detect a boom-down pilot pressure, for example.

Bucket adduction pilot pressure sensor 270 is configured to detect bucket adduction pilot pressure, for example.

The bucket swing pilot pressure sensor 280 is configured to detect a bucket swing pilot pressure, for example.

The first main pump pressure sensor 291 is for example configured to detect the pressure of the first main pump.

The second main pump pressure sensor 292 is configured to detect the pressure of the second main pump, for example.

In an embodiment of the present invention, there is provided a positive flow excavator 300 including: control device 310, boom 320, stick 330, stick retract solenoid 340, turret 350, bucket 360, first boom spool 370, first stick spool 380, first main pump 391, and second main pump 392.

The control device 310 is, for example, the control device 200 for a positive flow excavator according to any one of the foregoing embodiments. The specific function and details of the control device 310 may refer to the related descriptions of the foregoing embodiments, and are not repeated herein.

The control method 100 for a positive flow excavator, the control device 200 for a positive flow excavator, and the positive flow excavator 300 according to the embodiment of the present invention will be described in detail with reference to a specific example, and the specific contents of the examples of the present invention are as follows:

in order to achieve both operability and fuel efficiency of actions such as land leveling and the like, as shown in fig. 4, an example of the present invention provides a positive flow excavator control system and a control method based on arm electric control, wherein the control system mainly includes a left handle 101, a left traveling pedal 102, a right traveling pedal 103, a right handle 104, and a pilot pressure sensor group 200 (wherein 200-1 is an arm adduction pilot pressure sensor, 200-2 is an arm outswing pilot pressure sensor, 200-3 is a swing pilot pressure sensor, 200-4 is a left traveling pilot pressure sensor, 200-5 is a right traveling pilot pressure sensor, 200-6 is a boom lifting pilot pressure sensor, 200-7 is a boom lowering pilot pressure sensor, 200-8 is an arm adduction pilot pressure sensor, 200-9 is an arm outswing pilot pressure sensor), a main pump pressure sensor 201, a main pump pressure sensor 202, an electromagnetic valve 203, a main pump electromagnetic valve 204, a main pump 205, a main pump 206, an oil cylinder 301, an arm oil cylinder 302, an arm 2 spool 303, an arm 1 spool 304, an arm 1 spool, 2 spool 306, a display 401, a controller 403, an engine controller 502, an engine spool 501, and an outer arm adduction electromagnetic valve 502.

According to the control system of the positive flow excavator based on the bucket rod electric control, which is disclosed by the invention, a 307 movable arm priority logic valve is omitted, and the bucket rod adduction electromagnetic valve 501 and the bucket rod outward swing electromagnetic valve 502 are added. The controller is used for collecting the pilot pressure of the control handle and the pressure of the main pump, identifying different actions and different loads, and setting different control strategies for the valve core of the bucket rod according to the different actions and loads, so that the oil consumption and the operating efficiency are both considered while the operability of actions such as land leveling and the like are ensured, and the execution process of the bucket rod electric control-based positive flow excavator control method is described below with reference to the accompanying drawings.

1. Motion recognition

As shown in fig. 5, first, the operation recognition is performed, specifically, the signal of the pilot pressure sensor group 200 is collected by the controller 402, and it is recognized whether the current operation type is the arm single operation, that is, the arm single operation, the land leveling operation, the three operation combination, that is, the arm retraction arm lifting bucket retraction combination operation, or the operation other than the above three operations. The specific judgment rule is as follows:

1. and (3) the bucket rod inner order-collecting action:

as shown in the timing chart of the arm retraction determination signal, the controller 402 collects the signals of the pilot pressure sensor group 200, specifically, the signals of the pilot pressure sensors corresponding to the two handles, that is, the left handle 101 and the right handle 104, as shown in fig. 6, and normally, each pilot pressure ranges from 0 to 40bar, the opening pressure of the valve element ranges from 5bar to 7bar, and the pilot pressure is 0 when the handle is not operated, so that when the arm retraction pilot pressure is greater than or equal to 5bar, and the other pilot pressures corresponding to the handles (including the arm retraction pilot pressure, the swing pilot pressure, the boom lifting pilot pressure, the boom lowering pilot pressure, the bucket retraction pilot pressure, and the bucket retraction pilot pressure) are all less than 5bar, the controller 402 determines the current operation type of the excavator as the arm retraction.

2. Action on level ground

The operator achieves the level ground operation by lifting the boom and recovering the arm at the same time, and as shown in fig. 7, which is a timing chart of the level ground operation determination signal, when the arm adduction pilot pressure is greater than or equal to 5bar, the boom lifting pilot pressure is greater than or equal to 5bar, and other pilot pressures (including the arm outswing pilot pressure, the swing pilot pressure, the boom lowering pilot pressure, the bucket adduction pilot pressure, and the bucket outswing pilot pressure) corresponding to the operation handle are all less than 5bar, the controller 402 determines the current operation type of the excavator as the level ground operation.

3. Three-action compound

As shown in the timing chart of the three-action composite state judging signal shown in fig. 8, when the arm adduction pilot pressure is greater than or equal to 5bar, the boom lifting pilot pressure is greater than or equal to 5bar, the bucket adduction pilot pressure is greater than or equal to 5bar, and other pilot pressures corresponding to the control handle (including the arm outswing pilot pressure, the swing pilot pressure, the boom lowering pilot pressure and the bucket outswing pilot pressure) are all less than 5bar, the controller 402 judges the current action type of the excavator as the arm adduction boom lifting bucket adduction composite action, namely, the three-action composite state.

4. Other actions

When the corresponding judgment conditions of the three actions of the above 1 to 3 are not satisfied, the controller 402 judges the current action type of the excavator as other actions, that is, other actions except the three action types.

2. Bucket rod adduction valve core control

In order to ensure operability and simultaneously consider oil consumption and operation efficiency, the invention adopts different control strategies for different action types and different loads. The specific control strategy is as follows:

1. bucket rod inner receipt action

As shown in fig. 9, the conventional control strategy is to determine the control current of the arm adduction solenoid valve directly from the arm adduction pilot pressure, that is, the control current output from the controller 402 to the arm adduction solenoid valve 501 is in a linear relationship with the arm adduction pilot pressure. The formula corresponding to the conventional control strategy is as follows:

equation 1:

here, set_current is a control Current output to the arm adduction solenoid valve 501, pilot_armin is an arm adduction Pilot pressure, pilot_min is a minimum secondary pressure required when the arm 2 spool 303 is opened, and pilot_max is a minimum secondary pressure required when the arm 2 spool 303 is fully opened. The pilot_min has a value range of 5bar to 7bar, for example, 5bar, and the pilot_max has a value range of 20bar to 25bar, for example, 25bar.

The initial stage of the retraction of the bucket rod is to do work by gravity, and if the valve core 303 of the bucket rod 2 is too large in opening, a suction phenomenon can be generated due to insufficient flow, and if the opening is too small, throttling loss can be generated. To avoid this problem, in the present example, the controller 402 collects the pressure of the main pump 205 and the pressure of the main pump 206 through 201, 202 while collecting the arm adduction pilot pressure, and when the average pressure of the main pump 205 and the main pump 206 is less than 15Mpa, as shown in fig. 10, the controller 402 determines the current state of the excavator as a light load operation, and to avoid the occurrence of the suction phenomenon, the controller 402 sets the maximum secondary pressure allowed by the arm adduction solenoid valve 501 to set_arminpilot_max1, which is typically Set to a value of 20bar to 25bar, specifically, 25bar, for example. When the average pressures of the main pump 205 and the main pump 206 are 15Mpa or more, the controller 402 determines that the current state is a heavy duty operation, and in order to reduce the throttle loss, the controller 402 allows the maximum secondary pressure output from the arm adduction solenoid valve 501 to be in a linear relationship with the average pressures of the main pump 205 and the main pump 206 when the average pressures of the main pump 205 and the main pump 206 are 15Mpa to 25Mpa, and when the average pressures of the main pump 205 and the main pump 206 are 25Mpa or more, the controller 402 sets the maximum secondary pressure allowed from the arm adduction solenoid valve 501 to be Set to be in the range of, for example, 35bar to 40bar, and the Set to be in the range of, for example, 40bar.

The flow of specifically calculating the control current of the arm retraction solenoid 501 is as follows:

(1) Based on the average pressures of the main pump 205 and the main pump 206, the maximum secondary pressure that the arm adduction solenoid 501 allows to be set is calculated, as in equation 2.

Equation 2:

here, set_arminpilot_max is the maximum secondary pressure that the arm adduction solenoid valve 501 allows to Set, and av_pp1 and Pp2 are the average value of the pilot pressure of the main pump 205 and the pilot pressure of the main pump 206, and the value of set_arminpilot_max1 ranges from 20bar to 25bar, for example, and the specific value is 25bar, for example. The value range of set_arminpilot_max2 is, for example, 35bar to 40bar, and the specific value is, for example, 40bar.

(2) When the actual measured arm adduction pilot pressure is less than or equal to the maximum allowable Set secondary pressure, that is, set_arminpilot_max determined in the previous step (1), the control current of the arm adduction solenoid valve 501 is Set according to the conventional control strategy shown in fig. 9.

(3) When the actual-measured arm adduction pilot pressure is greater than the allowable Set maximum secondary pressure set_arminpilot_max, the control current of the arm adduction solenoid valve 501 is limited to the control current corresponding to the allowable Set maximum secondary pressure set_arminpilot_max in accordance with the conventional control strategy shown in fig. 9.

That is, if the arm adduction pilot pressure is less than or equal to the determined maximum secondary pressure set_armlnpilot_max, the control current to be output to the arm adduction solenoid valve corresponding to the arm adduction pilot pressure is determined according to the conventional control strategy shown in fig. 9, and if the arm adduction pilot pressure is greater than the determined maximum secondary pressure set_armlnpilot_max, the control current to be output to the arm adduction solenoid valve corresponding to the case where the arm adduction pilot pressure is determined to have the maximum secondary pressure set_armlnpilot_max in combination with fig. 9.

Through the method, the suction phenomenon during light load can be avoided, and the throttling loss during heavy load can be effectively reduced.

Summarizing, the control strategy for the case of the arm-in order action is: first, the maximum secondary pressure set_arminopilot_max allowed by the arm adduction solenoid 501 is determined based on the average pressure of the two main pumps, and then the control current output to the arm adduction solenoid 501 is determined based on the arm adduction pilot pressure and the determined maximum secondary pressure set_arminopilot_max allowed by the arm adduction solenoid 501 and the correspondence between the arm adduction pilot pressure and the arm adduction solenoid setting current in the conventional control strategy as shown in fig. 9.

2. Action on level ground

The operator performs the leveling operation by lifting the boom and the arm at the same time, and as shown in fig. 11, the vertical axis in fig. 11 indicates the height of the bucket tooth tip relative to the target work surface during the leveling operation, and is higher than the target work surface if it is positive, and lower than the target work surface if it is negative, and the ideal leveling operation is to control the leveling operation process in three stages in order to improve the leveling operation operability and to achieve fuel economy. The level ground operation differs from the control strategy of the arm deposit operation only in that the setting strategy of the maximum secondary pressure set_arminpilot_max that the arm deposit solenoid valve 501 allows to output is different. Specifically:

(1) Initial stage

If the boom lifting pilot pressure and the arm retracting pilot pressure are both greater than or equal to the preset full opening pressure, such as 25bar, the arm swinging pilot pressure, the swing pilot pressure, the boom lowering pilot pressure, the bucket retracting pilot pressure and the bucket swinging pilot pressure are both less than the preset opening pressure, such as 5bar, and the pressures of the main pump 205 and the main pump 206 are both less than 15Mpa, the initial stage of the land leveling operation is determined.

If the valve core of the arm 2 is opened too quickly in the initial stage, the bucket tooth tip is directly hit on the target working surface, so that the nodding phenomenon is generated when the track of the bucket tooth tip of the level ground work is lower than the target working surface, if the valve core of the arm 2 is opened too slowly, the bucket tooth tip is directly separated from the target working surface, so that the track of the bucket tooth tip of the level ground work is higher than the target working surface, so that in order to ensure the coordination of the lifting speed of the movable arm and the adduction speed of the arm, the controller 402 directly sets the maximum allowable output secondary pressure set_ArmInPilot_Max of the arm adduction solenoid valve 501 as set_ArmInPilot_Max3 in the initial stage, and the value range of set_ArmInPilot_Max3 is usually 10-15bar, for example, 12bar is specifically Set, and specific parameter value setting can be Set according to specific action effect.

(2) Intermediate stage

If the arm adduction pilot pressure is greater than or equal to a preset full-opening pressure, such as 25bar, the boom lifting pilot pressure is greater than or equal to a preset opening pressure and less than the preset full-opening pressure, the arm outswing pilot pressure, the swing pilot pressure, the boom lowering pilot pressure, the bucket adduction pilot pressure and the bucket outswing pilot pressure are all less than the preset opening pressure, and the pressures of the main pump 205 and the main pump 206 are all less than 15Mpa, the middle stage of the land leveling action is determined.

With the progress of the land leveling action, in order to ensure that the bucket tooth tips do not come off the target work surface in the intermediate stage, it is necessary to gradually reduce the boom lifting speed while accelerating the boom retraction speed, the boom lifting speed being controlled by reducing the opening of the boom manipulating handle by the manipulator, the boom retraction speed being controlled by gradually increasing the current of the boom retraction solenoid valve 501, thereby ensuring a longer land leveling distance,

as shown in fig. 12, when the boom raising pilot pressure is 25bar or more, the maximum secondary pressure set_arminpilot_max that the arm adduction solenoid valve 501 allows to output is directly Set to set_arminpilot_max3. When the actual measurement value of the boom-up pilot pressure is in the range of 25bar or less and 5bar or more, the maximum secondary pressure set_arminopilot_max that the arm adduction solenoid valve 501 is allowed to output is inversely proportional to the boom-up pilot pressure. The boom-up pilot pressure is set_arminpilot_max1 when it is less than 5bar. Specifically as shown in formula 3:

equation 3:

the set_arminpilot_max is the maximum secondary pressure that the arm adduction solenoid valve 501 is allowed to output, and the pilot_boom is the boom lifting Pilot pressure. The value range of set_arminpilot_max1 is, for example, 20bar to 25bar, and the specific value is, for example, 25bar. The value range of set_arminpilot_max3 is usually between 10 and 15bar, for example 12bar.

(3) End stage

If the boom lifting pilot pressure and the arm retracting pilot pressure are both greater than or equal to a preset opening pressure, such as 5bar, the arm swinging pilot pressure, the swing pilot pressure, the boom lowering pilot pressure, the bucket retracting pilot pressure and the bucket swinging pilot pressure are both less than the preset opening pressure, and the pressures of the main pump 205 and the main pump 206 are both greater than or equal to 15Mpa, then the end stage of the land leveling operation is determined.

At the end stage, in order to reduce fuel consumption, the method of setting the maximum secondary pressure set_arminpilot_max that the arm adduction solenoid valve 501 allows to output is the same as that at the time of the arm adduction single operation, and the controller 402 determines the corresponding set_arminpilot_max based on the average pressures of the two main pumps. Reference is specifically made to the foregoing descriptions, and no further description is given here.

For the three stages of the level ground action, after determining the maximum secondary pressure set_arminpilot_max that the fighting pole adduction solenoid valve 501 is allowed to output, the controller 402 determines the control current to be output to the fighting pole adduction solenoid valve 501 according to the determined maximum secondary pressure set_arminpilot_max and the arm adduction pilot pressure in the stage, and the specific method for determining the control current to be output to the arm adduction solenoid valve 501 according to the determined maximum secondary pressure set_arminpilot_max and the arm adduction pilot pressure in the stage is the same as the arm adduction single action, and will not be described in detail herein, and reference is made to the description of the foregoing parts.

Through the control of the three stages of the land leveling action, the operability of the initial stage and the land leveling distance of the middle stage can be ensured, and the fuel economy of the end stage can be considered.

3. Three-action compound

In the three-operation composite state, in order to ensure that the boom raising speed, the bucket retraction speed, and the arm retraction speed are coordinated, as shown in fig. 13, when the maximum value of the boom raising pilot pressure and the bucket retraction pilot pressure is 25bar or more, the arm retraction solenoid valve 501 outputs the maximum secondary pressure set_arminpilot_max to set_arminpilot_max4, and the set_arminpilot_max4 has a value in the range of 10 to 15bar, specifically, for example, a value of 12bar. When the maximum value of the boom-up pilot pressure and the bucket-in pilot pressure is less than 25bar and equal to or greater than 5bar, the maximum secondary pressure set_arminpilot_max that the arm-in solenoid valve 501 is allowed to output is inversely proportional to the maximum value of the boom-up pilot pressure and the bucket-in pilot pressure. When the maximum value of the boom-up pilot pressure and the bucket adduction pilot pressure is less than 5bar, the maximum secondary pressure set_arminpilot_max that the arm adduction solenoid valve 501 is allowed to output is set_arminpilot_max1, and the set_arminpilot_max1 is in the range of 20bar to 25bar, for example, and a specific value is 25bar, for example.

Here, set_arminpilot_max is the maximum secondary pressure that the arm adduction solenoid valve 501 is allowed to output, and Max is the maximum value of both the boom lifting pilot pressure and the bucket adduction pilot pressure.

4. Other actions

When judging that the front operation of the excavator is another operation, the controller 402 does not limit the maximum secondary pressure that the arm adduction solenoid 501 is allowed to output, and the controller 402 directly calculates the control current that needs to be output to the arm adduction solenoid 501 according to the conventional control strategy shown in fig. 9.

In summary, the embodiment of the invention adopts the electric control valve core through the bucket rod, recognizes different action types and different load conditions through collecting the pilot pressure of the control handle and the pressure of the main pump, sets different control strategies for the bucket rod valve core according to different action types and load conditions, controls the control current of the bucket rod adduction electromagnetic valve which is output to control the opening size of the bucket rod valve core, ensures the operability of various actions including the land leveling action, and can give consideration to oil consumption and working efficiency.

It will be appreciated by those skilled in the art that embodiments of the present invention may be provided as a method, system, or computer program product. Accordingly, the present invention may take the form of an entirely hardware embodiment, an entirely software embodiment or an embodiment combining software and hardware aspects. Furthermore, the present invention may take the form of a computer program product embodied on one or more computer-usable storage media (including, but not limited to, disk storage, CD-ROM, optical storage, and the like) having computer-usable program code embodied therein.

The present invention is described with reference to flowchart illustrations and/or block diagrams of methods, apparatus (systems) and computer program products according to embodiments of the invention. It will be understood that each flow and/or block of the flowchart illustrations and/or block diagrams, and combinations of flows and/or blocks in the flowchart illustrations and/or block diagrams, can be implemented by computer program instructions. These computer program instructions may be provided to a processor of a general purpose computer, special purpose computer, embedded processor, or other programmable data processing apparatus to produce a machine, such that the instructions, which execute via the processor of the computer or other programmable data processing apparatus, create means for implementing the functions specified in the flowchart flow or flows and/or block diagram block or blocks.

These computer program instructions may also be stored in a computer-readable memory that can direct a computer or other programmable data processing apparatus to function in a particular manner, such that the instructions stored in the computer-readable memory produce an article of manufacture including instruction means which implement the function specified in the flowchart flow or flows and/or block diagram block or blocks.

These computer program instructions may also be loaded onto a computer or other programmable data processing apparatus to cause a series of operational steps to be performed on the computer or other programmable apparatus to produce a computer implemented process such that the instructions which execute on the computer or other programmable apparatus provide steps for implementing the functions specified in the flowchart flow or flows and/or block diagram block or blocks.

In one typical configuration, a computing device includes one or more processors (CPUs), input/output interfaces, network interfaces, and memory.

The memory may include volatile memory in a computer-readable medium, random Access Memory (RAM) and/or nonvolatile memory, etc., such as Read Only Memory (ROM) or flash RAM. Memory is an example of a computer-readable medium.

Computer readable media, including both non-transitory and non-transitory, removable and non-removable media, may implement information storage by any method or technology. The information may be computer readable instructions, data structures, modules of a program, or other data. Examples of storage media for a computer include, but are not limited to, phase change memory (PRAM), static Random Access Memory (SRAM), dynamic Random Access Memory (DRAM), other types of Random Access Memory (RAM), read Only Memory (ROM), electrically Erasable Programmable Read Only Memory (EEPROM), flash memory or other memory technology, compact disc read only memory (CD-ROM), digital Versatile Discs (DVD) or other optical storage, magnetic cassettes, magnetic tape magnetic disk storage or other magnetic storage devices, or any other non-transmission medium, which can be used to store information that can be accessed by a computing device. Computer-readable media, as defined herein, does not include transitory computer-readable media (transshipment) such as modulated data signals and carrier waves.

It should also be noted that the terms "comprises," "comprising," or any other variation thereof, are intended to cover a non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements does not include only those elements but may include other elements not expressly listed or inherent to such process, method, article, or apparatus. Without further limitation, an element defined by the phrase "comprising one … …" does not exclude the presence of other like elements in a process, method, article or apparatus that comprises an element.

The foregoing is merely exemplary of the present invention and is not intended to limit the present invention. Various modifications and variations of the present invention will be apparent to those skilled in the art. Any modification, equivalent replacement, improvement, etc. which come within the spirit and principles of the invention are to be included in the scope of the claims of the present invention.

Claims

1. A control method for a positive flow excavator, the positive flow excavator including an arm, a boom, a bucket, and an arm adduction solenoid, the control method comprising:

acquiring the pilot pressure of the bucket rod adduction of the positive flow excavator;

Determining the action type of the positive flow excavator;

determining the maximum secondary pressure allowed by the bucket rod adduction electromagnetic valve under the condition that the action type is a preset action type, and determining the control current of the bucket rod adduction electromagnetic valve according to the maximum secondary pressure and the bucket rod adduction pilot pressure;

determining control current of the bucket rod adduction electromagnetic valve according to the bucket rod adduction pilot pressure under the condition that the action type is not the preset action type; and

outputting the control current to the bucket rod adduction electromagnetic valve so as to control the adduction speed of the bucket rod;

wherein the preset action type comprises one or more of the following:

the bucket rod receives the bill in;

a land leveling action; and

the bucket rod adduction movable arm promotes the bucket adduction compound action;

the positive flow excavator further comprises a turntable, and the determining the action type of the positive flow excavator comprises:

acquiring the bucket rod outward swing pilot pressure, the rotary pilot pressure, the movable arm lifting pilot pressure, the movable arm descending pilot pressure, the bucket adduction pilot pressure and the bucket outward swing pilot pressure of the positive flow excavator;

determining that the action type is the bucket arm adduction single action when the bucket arm adduction pilot pressure is greater than or equal to a preset opening pressure and the bucket arm adduction pilot pressure, the swing pilot pressure, the boom lifting pilot pressure, the boom lowering pilot pressure, the bucket adduction pilot pressure and the bucket adduction pilot pressure are all less than the preset opening pressure;

Determining that the action type is the land leveling action when the arm adduction pilot pressure and the boom lifting pilot pressure are both greater than or equal to a preset opening pressure and the arm outswing pilot pressure, the swing pilot pressure, the boom lowering pilot pressure, the bucket adduction pilot pressure and the bucket outswing pilot pressure are all less than the preset opening pressure; and

determining that the action type is the bucket-arm-adduction-boom-lifting-bucket adduction compound action under the conditions that the bucket-arm adduction pilot pressure, the boom-lifting pilot pressure, and the bucket adduction pilot pressure are all greater than or equal to the preset opening pressure, and the bucket-outswing pilot pressure, the swing pilot pressure, the boom-lowering pilot pressure, and the bucket-outswing pilot pressure are all less than the preset opening pressure;

the positive flow excavator further comprises a first main pump and a second main pump, and the determining of the maximum secondary pressure allowed by the bucket rod adduction solenoid valve comprises the following steps:

acquiring the pressure of the first main pump and the pressure of the second main pump under the condition that the action type is the in-arm order receiving action;

Determining the maximum secondary pressure from the pressure of the first main pump and the pressure of the second main pump;

determining a stage type of the land leveling action when the action type is the land leveling action;

determining the maximum secondary pressure according to the stage type;

acquiring a boom lifting pilot pressure and a bucket adduction pilot pressure of the positive flow excavator under the condition that the action type is the combined action of the boom adduction and the bucket adduction; and

determining the maximum secondary pressure according to the boom lifting pilot pressure and the bucket adduction pilot pressure;

wherein the phase type is selected from any one of a start phase, an intermediate phase and an end phase;

the determining the control current of the arm adduction solenoid valve according to the maximum secondary pressure and the arm adduction pilot pressure includes:

determining a control current of the arm adduction electromagnetic valve according to the arm adduction pilot pressure when the arm adduction pilot pressure is less than or equal to the maximum secondary pressure; and

and under the condition that the pilot pressure of the bucket rod adduction is larger than the maximum secondary pressure, determining the control current of the bucket rod adduction electromagnetic valve according to the maximum secondary pressure.

2. The control method according to claim 1, characterized in that the determining the maximum secondary pressure from the pressure of the first main pump and the pressure of the second main pump includes:

determining an average of the pressure of the first main pump and the pressure of the second main pump; and

and determining the maximum secondary pressure according to the average value.

3. The control method according to claim 2, characterized in that the determining the maximum secondary pressure from the average value includes:

determining the maximum secondary pressure according to the following formula:

；

wherein,Set_ArmInPilot_Maxfor the maximum secondary pressure to be mentioned,Aver_Pp1andPp2as a result of the mean value of the values,Set_ ArmInPilot_Max1 is a first preset maximum secondary pressure,Set_ArmInPilot_Max2 is a second preset maximum secondary pressure,Pp1 is a first preset main pump pressure,Pp2 is a second preset main pump pressure.

4. The control method according to claim 1, wherein the determining the stage type of the land leveling action includes:

determining the stage type as the ending stage when the pressure of the first main pump and the pressure of the second main pump are both greater than or equal to a third preset main pump pressure;

determining whether the arm adduction pilot pressure is greater than or equal to a preset full opening pressure and determining whether the boom lifting pilot pressure is greater than or equal to the preset full opening pressure when both the pressure of the first main pump and the pressure of the second main pump are less than the third preset main pump pressure;

Determining the stage type as the initial stage under the condition that the boom lifting pilot pressure and the arm adduction pilot pressure are both greater than or equal to the preset full opening pressure; and

and determining that the stage type is the intermediate stage when the boom lifting pilot pressure is determined to be smaller than the preset full-opening pressure and the arm adduction pilot pressure is determined to be greater than or equal to the preset full-opening pressure.

5. The control method according to claim 1, wherein the determining the maximum secondary pressure according to the stage type includes:

determining that the maximum secondary pressure is a third preset maximum secondary pressure in the case that the stage type is the initial stage;

determining the maximum secondary pressure according to the boom-up pilot pressure in the case where the stage type is the intermediate stage; and

and in the case that the stage type is the ending stage, determining the maximum secondary pressure according to the pressure of the first main pump and the pressure of the second main pump.

6. The control method of claim 5, wherein the positive flow excavator further comprises a first boom spool, the determining the maximum secondary pressure from the boom lift pilot pressure comprising:

Determining the maximum secondary pressure according to the following formula:

；

wherein,Set_ArmInPilot_Maxfor the maximum secondary pressure to be mentioned,Pilot_BoomUpthe pilot pressure is raised for the boom,Set_ArmInPilot_Max1 is a first preset maximum secondary pressure,Set_ArmInPilot_Max3 is the third preset maximum secondary pressure,Pbu1 is the minimum secondary pressure required when the first boom spool is open,Pbuand 2 is the minimum secondary pressure required when the first movable arm valve core is fully opened.

7. The control method of claim 1, wherein the determining the maximum secondary pressure from the boom-up pilot pressure and the bucket adduction pilot pressure comprises:

determining a maximum value of the boom-up pilot pressure and the bucket adduction pilot pressure; and

and determining the maximum secondary pressure according to the maximum value.

8. The control method according to claim 7, characterized in that the determining the maximum secondary pressure from the maximum value includes:

determining the maximum secondary pressure according to the following formula:

；

wherein,Set_ArmInPilot_Maxfor the maximum secondary pressure to be mentioned,BUandAIPilot_Maxat the point of the maximum value of the values,Set_ArmInPilot_Max1 is a first preset maximum secondary pressure,Set_ArmInPilot_Max4 is a fourth preset maximum secondary pressure,Pba1 is a first preset pressure value, and the pressure value is equal to the first preset pressure value,Pba2 is a second preset pressure.

9. The control method of claim 1, wherein the positive flow excavator further comprises a first stick spool, and wherein determining a control current of the stick adduction solenoid based on the stick adduction pilot pressure comprises:

the control current is determined according to the following formula:

；

wherein,Set_Currentfor the purpose of the control current mentioned above,Pilot_ArmInfor the pilot pressure to be received inside the arm,Pilot_ Minfor the minimum secondary pressure required when the first stick spool is open,Pilot_Maxfor the minimum secondary pressure required when the first stick spool is fully open,Current_Maxfor the upper limit value of the value range of the control current,Current_Minthe lower limit value of the value range of the control current is set.

10. The control method according to claim 9, characterized in that the determining of the control current of the arm adduction solenoid according to the maximum secondary pressure includes:

the control current is determined according to the following formula:

；

wherein,Set_Currentfor the purpose of the control current mentioned above,Set_ArmInPilot_Maxfor the maximum secondary pressure to be mentioned,Pilot_Minfor the minimum secondary pressure required when the first stick spool is open,Pilot_Maxfor the minimum secondary pressure required when the first stick spool is fully open,Current_Maxfor the upper limit value of the value range of the control current,Current_Minfor the lower limit value of the value range of the control current 。

11. A controller configured to perform the control method for a positive flow excavator according to any one of claims 1 to 10.

12. A control device for a positive flow excavator, the positive flow excavator including a boom, an arm adduction solenoid valve, a turntable, a bucket, a first boom spool, a first arm spool, a first main pump, and a second main pump, the control device comprising:

an arm adduction pilot pressure sensor configured to detect an arm adduction pilot pressure;

a boom out-swing pilot pressure sensor configured to detect a boom out-swing pilot pressure;

a rotary pilot pressure sensor configured to detect a rotary pilot pressure;

a boom-up pilot pressure sensor configured to detect a boom-up pilot pressure;

a boom-down pilot pressure sensor configured to detect a boom-down pilot pressure;

a bucket adduction pilot pressure sensor configured to detect bucket adduction pilot pressure;

a bucket outer swing pilot pressure sensor configured to detect bucket outer swing pilot pressure;

a first main pump pressure sensor configured to detect a pressure of the first main pump;

A second main pump pressure sensor configured to detect a pressure of the second main pump; and

the controller according to claim 11.

13. A positive flow excavator, comprising:

a movable arm;

a bucket rod;

an electromagnetic valve is retracted in the bucket rod;

a turntable;

a bucket;

a first boom spool;

a first stick spool;

a first main pump;

a second main pump; and

the control device for a positive flow excavator of claim 12.