Foundation flow control method based on full-electric-control positive flow excavator

Abstract

The invention discloses a basic flow control method based on a full-electric control positive flow excavator, which comprises the following steps of: controlling a main pump, setting a corresponding engine rotating speed, controlling the theoretical maximum flow of the main pump of an engine, controlling the displacement of the main pump through a current control proportional electromagnetic valve corresponding to a pilot handle, and providing the required flow for a hydraulic oil cylinder. And the working device is further controlled. In the working process, the current of the main pump proportional electromagnetic valve changes along with the pilot handle, and when the current reaches the maximum value, the flow reaches the maximum at the moment. Priority relations are set for actions in all parts of the working cycle, and in all parts of the loading process, all electric control valve elements preferentially control all action flows through a flow distribution algorithm, cooperative control over electro-hydraulic systems of the excavator and accurate control over working devices and special devices of the excavator are achieved, and therefore the development efficiency of the whole machine is improved, and the working efficiency of the excavator is improved. And the product development time is shortened, and different tonnages and special configuration requirements of the excavator are met.

Description

Technical Field

[0001] The invention relates to the technical field of excavators, and more specifically to a basic flow control method based on a fully electrically controlled positive flow excavator. Background Art

[0002] With the continuous development of industries such as gardening, construction and mining, the demand for excavators of different types, working conditions and configurations is increasing. In addition to fuel consumption, efficiency, smoothness and maneuverability, new requirements are also put forward for product types and development speed. The positive flow hydraulic system with high efficiency, flexibility and reliability, combined with the electronically controlled multi-way valve with high accuracy and fast response speed, can better meet the various usage needs of users, which also increases the difficulty of developing corresponding control methods.

[0003] How to speed up the development of control algorithms for excavators of various configurations to meet the use requirements of different working conditions, reasonably distribute the hydraulic oil of the excavator in various actuators, improve the maneuverability and accuracy of the vehicle, and at the same time meet the speed requirements of various working devices has become the main direction of current research.

[0004] Therefore, designing a coordinated control between the electro-hydraulic systems of the excavator, precise control of the excavator's working device and special devices, and thereby accelerating the overall machine development efficiency, shortening the product development time, and meeting the different tonnage and special configuration requirements of excavators is exactly the problem that the inventor wants to solve. Summary of the invention

[0005] In view of the shortcomings of the prior art, the purpose of the present invention is to provide a basic flow control method based on a fully electronically controlled positive flow excavator, which can achieve coordinated control between the excavator's electro-hydraulic systems and precise control of the excavator's working devices and special devices, thereby accelerating the development efficiency of the entire machine, shortening product development time, and meeting the functions of excavators of different tonnages and special configuration requirements.

[0006] The technical solution adopted by the device of the present invention is: a basic flow control method based on a fully electronically controlled positive flow excavator, which comprises the following steps: (1) Control the main pump and set the corresponding engine speed; (2) Control the theoretical maximum flow of the engine main pump, and control the displacement of the main pump by controlling the proportional solenoid valve corresponding to the current through the pilot handle; (3) Provide the required flow to the hydraulic cylinder, thereby controlling the working device; (4) During operation, the current of the main pump proportional solenoid valve changes with the pilot handle. When the current reaches the maximum value, the flow rate reaches the maximum; (5) The priority relationship of each action in the working cycle is set, and the priority and flow distribution algorithm of each electronically controlled valve core in each part of the loading process controls the flow of each action.

[0007] Furthermore, the control of the main pump in step (1) includes developing a personalized operation control strategy according to the operator's habits and working conditions. By learning the operator's operating habits, the controller automatically adjusts the flow distribution so that the excavator can achieve optimal performance under different working conditions.

[0008] Furthermore, the hydraulic cylinder in step (3) adopts a flow compensation reversing valve, including a main throttle valve and a flow supplement valve, to achieve more accurate flow distribution.

[0009] Furthermore, the method also includes step (6) of using advanced modeling and simulation technology to model the hydraulic system in detail, simulating the system behavior under different working conditions, identifying performance bottlenecks and potential failure points in advance, and optimizing the system design.

[0010] Furthermore, in step (5), the priority relationship is that the boom takes priority during excavation.

[0011] The beneficial effects of the device of the present invention are: 1. The present invention provides a basic flow control method based on a fully electronically controlled positive flow excavator. The method can achieve coordinated control between the electro-hydraulic systems of the excavator through an electric proportional hydraulic pump and an electronically controlled multi-way valve, in conjunction with the main valve opening characteristics, the system pressure collected by the pressure sensor, etc. It can also provide a basic control method platform for different application scenarios and configurations of the machine models according to different hydraulic components, actuators and working device parameters, which can be developed multiple times, speeding up the efficiency of the development of various configuration control methods and improving the standardization level of the excavator control method. DETAILED DESCRIPTION

[0012] The following is a further description of the device of the present invention in conjunction with specific embodiments, which are only used to illustrate the present invention and are not intended to limit the scope of the present invention. In addition, it should be understood that after reading the content taught by the device of the present invention, those skilled in the art can make various changes or modifications to the present invention, and these equivalent forms also fall within the scope limited by the claims attached to the application.

[0013] Embodiment 1: When the load of the actuator changes, the flow replenishment valve can automatically adjust the flow according to the instructions of the controller to ensure that the flow demand of the actuator is met. This compensation mechanism can effectively solve the problem of insufficient flow caused by load changes in traditional systems and improve the response speed and stability of the system.

[0014] To control the main pump, the engine speed of each gear of the excavator is fixed when there is no load. The main pump is driven by the engine, and the proportional solenoid valve is controlled by the corresponding current of the pilot handle to control the displacement of the main pump, provide the required flow for the hydraulic cylinder, and then control the working device.

[0015] In order to reduce the energy loss caused by engine overpower, the maximum power of each gear needs to be set, and the required flow rate is calculated in combination with the pressure sensor of the main pump. The formula is: W=PQ In the formula, W is power; P is pressure; Q is flow rate.

[0016] The flow rate is related to the main pump speed and displacement, namely: Q=nq Where n is the main pump speed; q is the main pump displacement.

[0017] The displacement of the main pump is controlled by controlling the proportional solenoid valve of the main pump. The formula is: q = f(I) Where I is the control current; f(I) is the function of current and displacement.

[0018] In the above, except for the pressure which is obtained from the sensor in real time, the other variables are the inherent properties of the main pump and can be replaced or changed as needed.

[0019] The working pressure of the excavator is determined by the external load, and the speed of the working device is limited by the flow rate, so the flow distribution, that is, the control of the main valve is the core content of the control method. Based on the loading operation, the working cycle of the excavator can be divided into four parts, namely excavation, rotation, loading and resetting. The working devices cooperate with each other in each part. Among them, excavation mainly includes arm retraction and bucket retraction with boom lifting; the rotation part includes rotation, boom lifting, arm retraction and bucket retraction to prevent materials from falling; the unloading actions include rotation, arm flip, bucket flip and arm lowering; finally, the excavator working device resets and restarts excavation. The actions include rotation, boom lowering, arm retraction and bucket retraction. Under ideal conditions, loading can be simply divided, but the working conditions are complicated in the actual operation process and the actions are more arbitrary, so the working device is used as a variable for division during resetting, that is, no distinction is made between retraction and flip.

[0020] During the working process, the speed of each gear of the excavator is certain, and the current of the main pump proportional solenoid valve changes with the pilot handle. When the current reaches the maximum value, the inclination angle of the main pump swash plate reaches the maximum, that is, the displacement is the largest, and the flow rate reaches the maximum at this time. In order to ensure the smooth operation of each working device, the actions in each part of the working cycle need to be set with priority relationships. Among them, excavation is mainly based on the bucket arm, rotation is mainly based on the boom and rotation, unloading is mainly based on the bucket arm and bucket, and reset is distributed proportionally.

[0021] At the same time, the flow rate is affected by the multi-way valve core, and the pilot threshold is set to determine the degree of action execution and divide the cycle range. When digging: AmIn1+X1BmUp2+xBcIn2=C1 AmIn2+X2BmUp1+xBcIn1=C2 Among them, AmIn1 and AmIn2 are the current preset values ​​of the boom retraction valve core 1 and 2 corresponding to the pilot handle; xBcIn1 and xBcIn2 are the calculated current values ​​of the bucket retraction valve core 1 and 2, which need to be used after taking the smaller of the preset values; BmUp1 and BmUp2 are the current preset values ​​of the boom up valve core 1 and 2 corresponding to the pilot handle; C1 and C2 are the total current of the valve core opening during the excavation process, which are determined by the pilot pressure and the main pump flow; X1 and X2 are the excavation limit constants of the boom valve core, which are affected by factors such as the handle opening and action priority. Likewise, during the rotation process: BmUp1+Y1AmIn2+xBcIn1=D1 BmUp2+Y2AmIn1+xBcIn2+Z1Sw=D2 Among them, Y1 and Y2 are the arm valve core rotation limit constants, which are affected by factors such as handle opening and action priority; Sw is the preset value of the rotation current; Z1 is the boom priority constant relative to the rotation; D1 and D2 are the total valve core opening current during the rotation process, which is determined by the pilot pressure and the main pump flow.

[0022] The unloading process includes: Am1+X3Bm2+xBcOut2+Z1Sw=E1 Am2+X4Bm1+xBcOut1=E2 Among them, Am1 and Am2 are the preset current values ​​of the boom valve core 1 and 2 corresponding to the pilot handle; X3 and X4 are the unloading limit constants of the boom valve core, which are affected by factors such as the handle opening and action priority; Bm1 and Bm2 are the preset current values ​​of the boom valve core 1 and 2 corresponding to the pilot handle; xBcOut1 and xBcOut2 are the calculated current values ​​of the bucket overturning 1 and 2 valve cores, which need to be used after taking the smaller of the preset values; E1 and E2 are the total current of the valve core opening during the unloading process, which are determined by the pilot pressure and the main pump flow.

[0023] The reset process after unloading is: BmDn1+Am2+xBcIn1=F1 BmDn2+Am1+xBcIn2+Sw=F2 Among them, BmDn1 and BmDn2 are the corresponding valve core currents of the boom lowering pilot; F1 and F2 are the total valve core opening currents during the reset process, which are determined by the pilot pressure and the main pump flow.

[0024] The present invention provides a basic flow control method based on a fully electronically controlled positive flow excavator. The method can realize the coordinated control between the electro-hydraulic systems of the excavator through an electric proportional hydraulic pump and an electronically controlled multi-way valve, in conjunction with the main valve opening characteristics, the system pressure collected by the pressure sensor, etc., and can also provide a basic control method platform for different application scenarios and configurations of the machine models according to different hydraulic components, actuators and working device parameters, which can be developed multiple times, speeding up the efficiency of the development of various configuration control methods and improving the standardization level of the excavator control method.

Claims

1. A basic flow control method based on a fully electronically controlled positive flow excavator, comprising the following steps: (1) Control the main pump and set the corresponding engine speed; (2) Control the theoretical maximum flow of the engine main pump, and control the displacement of the main pump by controlling the proportional solenoid valve corresponding to the current through the pilot handle; (3) Provide the required flow to the hydraulic cylinder, thereby controlling the working device; (4) During operation, the current of the main pump proportional solenoid valve changes with the pilot handle. When the current reaches the maximum value, the flow rate reaches the maximum; (5) The priority relationship of each action in the working cycle is set, and the priority and flow distribution algorithm of each electronically controlled valve core in each part of the loading process controls the flow of each action.

2. A basic flow control method based on a fully electronically controlled positive flow excavator according to claim 1, characterized in that: The control of the main pump in step (1) includes developing a personalized operation control strategy according to the operator's habits and working conditions. By learning the operator's operating habits, the controller automatically adjusts the flow distribution so that the excavator can achieve optimal performance under different working conditions.

3. A basic flow control method based on a fully electronically controlled positive flow excavator according to claim 1, characterized in that: The hydraulic cylinder in step (3) adopts a flow compensation reversing valve, including a main throttle valve and a flow supplement valve, to achieve more accurate flow distribution.

4. A basic flow control method based on a fully electronically controlled positive flow excavator according to claim 1, characterized in that: The method also includes step (6) of using advanced modeling and simulation technology to model the hydraulic system in detail, simulating the system behavior under different working conditions, identifying performance bottlenecks and potential failure points in advance, and optimizing the system design.

5. The basic flow control method based on a fully electronically controlled positive flow excavator according to claim 1 is characterized in that: The priority relationship in step (5) is that the dipper arm takes priority during excavation.