Control method and control system of excavator and excavator

Abstract

The invention discloses a control method and system of an excavator and the excavator, and belongs to the technical field of mechanical control. The control method of the excavator is applied to a controller of the excavator. The excavator further comprises an actuator, an engine, a main pump connected with the engine and a main valve connected with the main pump. The control method of the excavator comprises the steps that an operation instruction is received, and i to-be-executed actions corresponding to the operation instruction are determined; determining a target valve link and a target rotor plunger pump according to the action type of the action to be executed; all the target valve links are opened; and the engine is controlled to provide power for all the target rotor plunger pumps, so that the target rotor plunger pumps convey hydraulic oil to corresponding actuators through the target valve links. The oil supply capacity of the excavator can be improved on the premise that throttling loss is not generated.

Description

Technical Field

[0001] The present application relates to the technical field of mechanical control, and particularly relates to a control method and a control system for an excavator, and an excavator. Background Art

[0002] An excavator can perform actions such as boom (BOOM), arm (ARM), bucket (BUCKET, BKT), swing (SWING, SW), travel left (TRAVEL LEFT, TL), and travel right (TRAVEL RIGHT, TR). During operation, the excavator generally mainly performs four actions: boom, arm, bucket, and swing. The excavator should not only be able to perform a single action independently, but in some working conditions, the excavator often needs to perform two or more actions simultaneously, which is called a compound action.

[0003] When performing a compound action, the loads of each action are different. In theory, a high-load action requires more allocated flow than a low-load action to make each action execute coordinately and respond quickly. However, in practice, hydraulic oil often preferentially flows into the low-load action oil circuit, making the high-load action slow and weak. Therefore, when performing a compound action, it is necessary to restrict the hydraulic oil flowing to the low-load oil circuit to ensure that enough hydraulic oil flows into the high-load oil circuit. Related technologies usually set a throttle valve on the low-load oil circuit to reduce its passing flow, so that more flow can be allocated to the high-load oil circuit. However, the above method using a throttle valve will cause throttling losses and reduce the system energy efficiency.

[0004] Therefore, how to improve the oil supply capacity of an excavator without generating throttling losses is a technical problem that those skilled in the art need to solve currently. Summary of the Invention

[0005] The purpose of the present application is to provide a control method and a control system for an excavator, and an excavator, which can improve the oil supply capacity of the excavator without generating throttling losses.

[0006] To solve the above technical problem, the present application provides a control method for an excavator, which is applied to a controller of the excavator. The excavator further includes an actuator, an engine, a main pump connected to the engine, and a main valve connected to the main pump. A plurality of rotor piston pumps are arranged in the main pump, and a plurality of valve groups are arranged in the main valve. The rotor piston pumps and the valve groups are in one-to-one correspondence. Each valve group includes a plurality of valve unions, and the valve unions are connected to the corresponding actuators. The control method for the excavator includes:

[0007] Receiving an operation instruction and determining i to-be-executed actions corresponding to the operation instruction;

[0008] Determining a target valve union and a target rotor piston pump according to the action types of the to-be-executed actions;

[0009] Open all the target valve unions;

[0010] Control the engine to supply power to all the target rotor piston pumps, so that the target rotor piston pumps deliver hydraulic oil to the corresponding actuators through the target valve unions.

[0011] Optionally, determining the target valve unions and target rotor piston pumps according to the action type of the to-be-executed action includes:

[0012] Determine the corresponding target actuator according to the action type of the to-be-executed action;

[0013] Set the valve union connected to the target actuator as the target valve union;

[0014] Set the rotor piston pump corresponding to the valve union group where the target valve union is located as the alternative rotor piston pump;

[0015] Determine the power demand value corresponding to the target actuator, and determine the number of pumps j according to the power demand value;

[0016] Select j alternative rotor piston pumps as the target rotor piston pumps.

[0017] Optionally, controlling the engine to supply power to all the target rotor piston pumps includes:

[0018] Calculate the output power of the target rotor piston pumps according to the corresponding relationship between the to-be-executed action and the target rotor piston pumps;

[0019] Control the engine to supply power to the corresponding target rotor piston pumps according to the output power.

[0020] This application also provides a control system for an excavator, which is applied to the controller of the excavator. The excavator further includes an actuator, an engine, a main pump connected to the engine, and a main valve connected to the main pump; a plurality of rotor piston pumps are arranged in the main pump, a plurality of valve union groups are arranged in the main valve, the rotor piston pumps and the valve union groups are in one-to-one correspondence, each valve union group includes a plurality of valve unions, the valve unions are connected to the corresponding actuators, and the control system of the excavator includes:

[0021] An instruction receiving module, configured to receive an operation instruction and determine i to-be-executed actions corresponding to the operation instruction;

[0022] A valve union and pump selection module, configured to determine target valve unions and target rotor piston pumps according to the action type of the to-be-executed action;

[0023] A valve union control module, configured to open all the target valve unions;

[0024] The pump control module controls the engine to supply power to all the target rotor piston pumps, so that the target rotor piston pumps deliver hydraulic oil to the corresponding actuators through the target valve units.

[0025] This application also provides an excavator, which includes a controller, actuators, an engine, a main pump connected to the engine, and a main valve connected to the main pump; a plurality of rotor piston pumps are arranged in the main pump, a plurality of valve unit groups are arranged in the main valve, the rotor piston pumps and the valve unit groups correspond to each other one by one, each valve unit group includes a plurality of valve units, and the valve units are connected to the corresponding actuators;

[0026] The operations performed by the controller when working include:

[0027] Receiving an operation instruction and determining i pending actions corresponding to the operation instruction;

[0028] Determining the target valve unit and the target rotor piston pump according to the action type of the pending actions;

[0029] Opening all the target valve units;

[0030] Controlling the engine to supply power to all the target rotor piston pumps, so that the target rotor piston pumps deliver hydraulic oil to the corresponding actuators through the target valve units.

[0031] Optionally, the rotor piston pump is connected to the corresponding valve unit group through an output pipeline, and a check valve is arranged on the output pipeline.

[0032] Optionally, the excavator includes a first engine, a second engine, a first main pump, a second main pump, a first main valve, and a second main valve;

[0033] The first engine is connected to the first main pump, and N rotor piston pumps are arranged in the first main pump; the second engine is connected to the second main pump, and M rotor piston pumps are arranged in the second main pump;

[0034] The first main valve includes N valve unit groups, and the valve unit groups in the first main valve correspond to the rotor piston pumps in the first main pump one by one; the second main valve includes M valve unit groups, and the valve unit groups in the second main valve correspond to the rotor piston pumps in the second main pump one by one.

[0035] Optionally, a first rotor piston pump and a second rotor piston pump are arranged in the first main pump, and a third rotor piston pump and a fourth rotor piston pump are arranged in the second main pump;

[0036] The first main valve includes a first valve unit group and a second valve unit group;

[0037] The second main valve includes a third valve assembly group and a fourth valve assembly group;

[0038] The first rotor piston pump is connected to the first valve assembly group through an output pipeline, the second rotor piston pump is connected to the second valve assembly group through an output pipeline, the third rotor piston pump is connected to the third valve assembly group through an output pipeline, and the fourth rotor piston pump is connected to the fourth valve assembly group through an output pipeline.

[0039] Optionally, the valve assemblies in the valve assembly group include:

[0040] A boom main flow valve assembly and a boom auxiliary confluence valve assembly connected to the boom cylinder;

[0041] A bucket main flow valve assembly and a bucket auxiliary confluence valve assembly connected to the bucket cylinder;

[0042] An arm main flow valve assembly and an arm auxiliary confluence valve assembly connected to the arm cylinder;

[0043] A swing valve assembly connected to the swing motor;

[0044] A left travel valve assembly connected to the left travel motor.

[0045] A right travel valve assembly connected to the right travel motor;

[0046] A straight travel valve assembly connected to the left travel motor and the right travel motor respectively.

[0047] Optionally, the rotor piston pumps in the main pump are connected in series.

[0048] The present application provides a control method for an excavator. The excavator to which the method is applied includes a controller, an engine, a main pump connected to the engine, and a main valve connected to the main pump. A plurality of rotor piston pumps are provided in the main pump, and a plurality of valve groups are provided in the main valve. The rotor piston pumps and the valve groups correspond to each other one by one. Each valve group includes a plurality of valve units, and each valve unit is connected to a corresponding actuator. After receiving an operation instruction, the controller determines i corresponding actions to be executed according to the operation instruction, and selects a corresponding target valve group and a target rotor piston pump according to the actions to be executed. The present application only opens the target valve group and controls the engine to supply power to the target rotor piston pump, so that hydraulic oil flows to the designated actuator. This targeted control reduces the flow of hydraulic oil in non-target paths and avoids energy loss caused by throttling. The present application can dynamically adjust the flow rate and pressure of hydraulic oil and the distribution mode of hydraulic oil according to actual needs, without relying on a fixed throttling device. Therefore, the present application can improve the oil supply capacity of the excavator without generating throttling losses. The present application also provides a control system for an excavator and an excavator, which have the above beneficial effects and will not be elaborated here. BRIEF DESCRIPTION OF THE DRAWINGS

[0049] In order to more clearly illustrate the embodiments of the present application, the drawings required for use in the embodiments will be briefly introduced below. Obviously, the drawings in the following description are only some embodiments of the present application. For those of ordinary skill in the art, other drawings can be obtained based on these drawings without creative efforts.

[0050] Figure 1 FIG. is a schematic structural diagram of an excavator provided by an embodiment of the present application;

[0051] Figure 2 FIG. is a flowchart of a control method for an excavator provided by an embodiment of the present application;

[0052] Figure 3 FIG. is a schematic diagram of a hydraulic distributed system provided by an embodiment of the present application. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0053] To make the objectives, technical solutions, and advantages of the embodiments of the present application clearer, the technical solutions in the embodiments of the present application will be clearly and completely described below with reference to the drawings in the embodiments of the present application. Obviously, the described embodiments are some, but not all, of the embodiments of the present application. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present application without creative efforts fall within the scope of protection of the present application.

[0054] Please refer to the following Figure 1 , Figure 1Schematic diagram of the structure of an excavator provided by an embodiment of the present application. The excavator includes: a controller, an actuator, an engine, a main pump connected to the engine, and a main valve connected to the main pump.

[0055] A plurality of rotor piston pumps are arranged in the main pump, and a plurality of valve connection groups are arranged in the main valve. The rotor piston pumps and the valve connection groups correspond one by one. Each valve connection group includes a plurality of valve connections, and the valve connections are connected to the corresponding actuators. In this embodiment, the engine, the main pump, and the main valve can be any number. The above main pump is a series pump, that is, the rotor piston pumps in the main pump are connected in series. The valve connection includes a valve body, a valve core, front and rear end covers, and a relief valve.

[0056] The rotor piston pump is used to deliver hydraulic oil to the valve connections in the corresponding valve connection group, so as to provide kinetic energy for the corresponding actuator.

[0057] A plurality of rotor piston pumps are arranged in the main pump, and the output of each rotor piston pump is directly connected to the corresponding valve connection group, so that each rotor piston pump only provides hydraulic oil for a group of actuators. Each valve connection group contains a plurality of valve connections, and these valve connections respectively control the flow direction of hydraulic oil to different actuators to drive the actuators to complete the required operations.

[0058] The controller is respectively connected to the main pump and the main valve, and is used to control any rotor piston pump in the main pump, and is also used to control any valve connection in the main valve.

[0059] Among them, the controller can dynamically adjust the state of each rotor piston pump according to actual needs, so as to control the start and stop of any number of rotor piston pumps; the controller can also dynamically adjust the state of any valve connection in the main valve according to actual needs, so as to control the on-off, flow rate, and flow direction of the valve connection.

[0060] Please refer to the following Figure 2 , Figure 2 Flowchart of a control method for an excavator provided by an embodiment of the present application. The above control method is applied to the controller of the excavator and includes the following steps:

[0061] S201: Receive an operation instruction and determine i pending actions corresponding to the operation instruction;

[0062] Among them, this embodiment can receive operation instructions issued by a control panel or other control terminals. The operation instructions can be instructions corresponding to a single action or a composite action. This embodiment can determine the i pending actions corresponding to the operation instruction according to the identifier included in the operation instruction and the corresponding relationship between the identifier and the action; i≥1.

[0063] S202: Determine a target valve connection and a target rotor piston pump according to the action type of the pending action;

[0064] Among them, each execution action (such as bucket lifting, boom lowering, etc.) has its specific hydraulic path and power requirement. In this embodiment, the actuator corresponding to the action type of the action to be executed can be determined, the valve union connected to the above actuator is set as the target valve union, and the rotor piston pump connected to the valve union group where the target valve union is located is set as the target rotor piston pump.

[0065] S203: Open all the target valve unions;

[0066] Among them, after the target valve union is determined, all the target valve unions can be opened. At this time, other valve unions except the target valve union are default in the closed state. Opening the valve union is an operation that allows hydraulic oil to pass through the valve union, and the valve union in the closed state prohibits hydraulic oil from passing through.

[0067] S204: Control the engine to provide power to all the target rotor piston pumps, so that the target rotor piston pumps deliver hydraulic oil to the corresponding actuators through the target valve unions.

[0068] Among them, the output shaft of the engine usually drives the target rotor piston pump through mechanical transmission. The target rotor piston pump converts the mechanical energy of the engine into hydraulic energy, and then delivers the hydraulic oil to the actuator through the target valve union, so as to drive the actuator to complete the action to be executed corresponding to the operation instruction. After the action to be executed is completed, the controller can close the above target valve union.

[0069] This embodiment provides a control method for an excavator. The excavator applied includes a controller, an engine, a main pump connected to the engine, and a main valve connected to the main pump. A plurality of rotor piston pumps are arranged in the main pump, a plurality of valve union groups are arranged in the main valve, the rotor piston pumps and the valve union groups are in one-to-one correspondence, each valve union group includes a plurality of valve unions, and the valve unions are connected to the corresponding actuators. After receiving an operation instruction, the controller determines the corresponding i actions to be executed according to the operation instruction, and selects the corresponding target valve union and target rotor piston pump according to the above actions to be executed. This embodiment only opens the target valve union and controls the engine to provide power to the target rotor piston pump, so that the hydraulic oil flows to the specified actuator. The above targeted control reduces the flow of hydraulic oil in non-target paths and avoids energy loss caused by throttling. This embodiment can dynamically adjust the flow rate and pressure of hydraulic oil and the distribution mode of hydraulic oil according to actual needs, without relying on a fixed throttling device. Therefore, this embodiment can improve the oil supply capacity of the excavator without generating throttling loss.

[0070] As a further introduction to Figure 1 the corresponding embodiment, the target valve union and target rotor piston pump can be determined in the following manner:

[0071] Step 1: Determine a corresponding target actuator according to the action type of the to-be-executed action;

[0072] In this step, the action type of the to-be-executed action can be determined (such as bucket-related actions, boom-related actions, etc.). Each action type corresponds to one or more hydraulic actuators. Based on the above corresponding relationship, the target actuator corresponding to the action type of the to-be-executed action can be determined; for example, the target actuator corresponding to the action type of bucket-related actions is the bucket.

[0073] Step 2: Set the valve bank connected to the target actuator as the target valve bank;

[0074] Among them, after determining the target actuator, in this embodiment, the valve bank connected to the target actuator can be further determined and set as the target valve bank.

[0075] Step 3: Set the rotor piston pump corresponding to the valve bank group where the target valve bank is located as the alternative rotor piston pump;

[0076] After determining the target valve bank, the valve bank group where the target valve bank is located can be determined, and the rotor piston pump connected to the valve bank group can be set as the alternative rotor piston pump.

[0077] Step 4: Determine the power demand value corresponding to the target actuator, and determine the number of pumps j according to the power demand value;

[0078] Each actuator has its corresponding requirement when completing an action. In this embodiment, the corresponding power demand value can be queried according to the type of the target actuator. Each rotor piston pump has its maximum output power. Therefore, in this embodiment, the number of pumps j can be determined according to the power demand value; specifically, in this embodiment, the number of pumps j can be determined according to the power demand value and the maximum power of the rotor piston pump.

[0079] Step 5: Select j alternative rotor piston pumps as the target rotor piston pumps.

[0080] After determining the required number of pumps j, the controller will select j pumps from the alternative rotor piston pumps as the target rotor piston pumps.

[0081] As a further introduction to the Figure 1 corresponding embodiment, the engine can be controlled to supply power to all target rotor piston pumps in the following way: calculate the output power of the target rotor piston pumps according to the corresponding relationship between the to-be-executed action and the target rotor piston pumps; control the engine to supply power to the corresponding target rotor piston pumps according to the output power.

[0082] An embodiment of the present application further provides an excavator, which includes a controller, an actuator, an engine, a main pump connected to the engine, and a main valve connected to the main pump; a plurality of rotor piston pumps are arranged in the main pump, and a plurality of valve groups are arranged in the main valve. The rotor piston pumps and the valve groups correspond one by one. Each valve group includes a plurality of valve unions, and the valve unions are connected to the corresponding actuators;

[0083] The operations performed by the controller when working include:

[0084] Receiving an operation instruction and determining i to-be-executed actions corresponding to the operation instruction;

[0085] Determining a target valve group and a target rotor piston pump according to the action type of the to-be-executed actions;

[0086] Opening all the target valve groups;

[0087] Controlling the engine to provide power to all the target rotor piston pumps, so that the target rotor piston pumps deliver hydraulic oil to the corresponding actuators through the target valve groups.

[0088] In this embodiment, a plurality of rotor piston pumps are arranged in the main pump, and a plurality of valve groups are arranged in the main valve. The rotor piston pumps and the valve groups correspond one by one. Each valve group includes a plurality of valve unions, and the valve unions are connected to the corresponding actuators. The controller is respectively connected to the main pump and the main valve, and can precisely control each rotor piston pump and valve union. Therefore, the excavator can dynamically adjust the flow rate and pressure of the hydraulic oil and the distribution mode of the hydraulic oil according to actual needs, without relying on a fixed throttling device. Therefore, this embodiment can improve the oil supply capacity of the excavator without generating throttling losses.

[0089] As a further introduction to the above embodiment, the rotor piston pump is connected to the corresponding valve group through an output pipeline, and a one-way valve is arranged on the output pipeline to prevent the oil from flowing back and causing the pump to reverse and drive the engine to reverse and damage the engine when a certain pump does not work.

[0090] As a further introduction to the above embodiment, the above excavator includes a joystick connected to the controller, and the joystick is used to send a corresponding control signal to the controller when reaching a preset gear position.

[0091] As a further introduction to the above embodiment, the above excavator includes a first engine, a second engine, a first main pump, a second main pump, a first main valve and a second main valve;

[0092] The first engine is connected to the first main pump, and N rotor piston pumps are arranged in the first main pump; the second engine is connected to the second main pump, and M rotor piston pumps are arranged in the second main pump;

[0093] The first main valve includes N valve connection groups, and the valve connection groups in the first main valve correspond one by one to the rotor piston pumps in the first main pump; the second main valve includes M valve connection groups, and the valve connection groups in the second main valve correspond one by one to the rotor piston pumps in the second main pump; each valve connection group includes a plurality of valve unions, and the valve unions are connected to the actuators of the excavator. N≥1, M≥1.

[0094] As a further introduction to the above embodiment, a first rotor piston pump and a second rotor piston pump are arranged in the first main pump, and a third rotor piston pump and a fourth rotor piston pump are arranged in the second main pump;

[0095] Taking N = 2 and M = 2 as an example, the first main valve includes a first valve connection group and a second valve connection group; the second main valve includes a third valve connection group and a fourth valve connection group; correspondingly, the first rotor piston pump is connected to the first valve connection group through an output pipeline, the second rotor piston pump is connected to the second valve connection group through an output pipeline, the third rotor piston pump is connected to the third valve connection group through an output pipeline, and the fourth rotor piston pump is connected to the fourth valve connection group through an output pipeline.

[0096] As a further introduction to the above embodiment, the valve unions in the valve connection group include: a boom main flow valve union and a boom auxiliary confluence valve union connected to the boom cylinder; a bucket main flow valve union and a bucket auxiliary confluence valve union connected to the bucket cylinder; a boom main flow valve union and a boom auxiliary confluence valve union connected to the boom cylinder; a slewing valve union connected to the slewing motor; a left travel valve union connected to the left travel motor. A right travel valve union connected to the right travel motor; a straight travel valve union connected to the left travel motor and the right travel motor respectively.

[0097] Further, the valve unions in the first valve connection group include:

[0098] A boom main flow valve union connected to the boom cylinder;

[0099] A bucket auxiliary confluence valve union connected to the bucket cylinder;

[0100] A boom auxiliary confluence valve union connected to the boom cylinder;

[0101] A slewing valve union connected to the slewing motor;

[0102] A left travel valve union connected to the left travel motor.

[0103] Further, the valve unions in the second valve connection group include:

[0104] The dipper stick auxiliary flow combining valve union connected to the dipper stick cylinder;

[0105] The dipper main flow valve union connected to the dipper cylinder;

[0106] The boom main flow valve union connected to the boom cylinder;

[0107] The right travel valve union connected to the right travel motor;

[0108] The straight travel valve union respectively connected to the left travel motor and the right travel motor.

[0109] Furthermore, the valve unions in the third valve union group include:

[0110] The dipper main flow valve union connected to the dipper cylinder;

[0111] The dipper stick auxiliary flow combining valve union connected to the dipper cylinder;

[0112] The boom auxiliary flow combining valve union connected to the boom cylinder;

[0113] The swing valve union connected to the swing motor;

[0114] The left travel valve union connected to the left travel motor.

[0115] Furthermore, the valve unions in the fourth valve union group include:

[0116] The dipper stick auxiliary flow combining valve union connected to the dipper cylinder;

[0117] The dipper main flow valve union connected to the dipper cylinder;

[0118] The boom main flow valve union connected to the boom cylinder;

[0119] The right travel valve union connected to the right travel motor;

[0120] The straight travel valve union respectively connected to the left travel motor and the right travel motor.

[0121] The arm main flow valve (i.e., arm control valve or arm valve group) is used to control the movement of the arm. The bucket auxiliary merging valve (i.e., bucket auxiliary flow merging valve or merging valve) is used to merge the hydraulic oil flow from different pumps to provide additional hydraulic power to the bucket cylinder, thereby increasing the movement speed or force of the bucket. The boom auxiliary merging valve (i.e., boom auxiliary flow merging valve or merging valve) is used to merge the hydraulic oil flow from different pumps to provide additional hydraulic power to the boom cylinder. The swing valve is used to control the swing movement of the excavator. The left travel valve is used to control the movement of the left travel motor. The arm auxiliary merging valve is used to merge the hydraulic oil flow from different pumps to provide additional hydraulic power to the arm cylinder. The bucket main flow valve is used to control the movement of the bucket cylinder. The boom main flow valve is used to control the movement of the boom cylinder. The right travel valve is used to control the movement of the right travel motor. The linear travel valve controls the movement of the left and right travel motors. The linear travel valve merges the hydraulic oil on the left and right sides, allowing the travel motors on the left and right sides to obtain the same flow rate and achieve linear travel.

[0122] The process described in the above embodiment is explained below through an embodiment in actual application.

[0123] In order to prevent the throttle valve from generating throttling loss, a closed rotary system can be used for the rotary actuator, that is, the hydraulic pump is directly connected to the rotary motor to form a closed loop system, and the movement of the rotary motor is directly controlled by the pump output pressure and flow. This circuit belongs to the volume speed control circuit, does not require the throttling control of the throttle valve, and the overall energy efficiency of the circuit is high. However, the closed rotary is expensive, inefficient, accompanied by start-stop jitter, and large drift. When the action is about to be completed, the hydraulic pump will slowly reduce the output pressure and flow, and the rotary motor will also slowly slow down the speed of executing the action. It will not stop immediately and will slip for a considerable distance. This phenomenon is caused by the structural characteristics of the closed rotary. At present, for compound actions, it is just a simple superposition of single actuator circuits, and each pump is only responsible for a certain action, which will lead to an increase in the number of pumps and an increase in cost. The power sources of each actuator in this scheme must operate at peak power, which greatly increases the total installed power, weight and volume of the system. Since each pump works alone, there will be incoordination during compound actions; during single actions, other pumps cannot provide it with flow, so the speed of single actions cannot be accelerated. Therefore, the related technologies have the following problems: (1) Throttling loss caused by using a throttle valve when the excavator performs compound actions; 2) Flow distribution is limited when the excavator performs compound actions; 3) It is difficult to balance speed and action coordination when the excavator performs compound actions; 4) When the traditional distributed system performs a single action, other pumps cannot provide it with flow.

[0124] In view of the technical problems existing in the above related technologies, this embodiment provides a hydraulic distributed system and its control strategy for a dual-engine excavator. The excavator involved in this embodiment adopts dual engines, and the hydraulic system is also designed with dual pumps and dual valves. The control system directly and reasonably distributes the flow rate, without causing throttling losses, and the compound action speed is fast and the actions are coordinated.

[0125] Please refer to Figure 3 , Figure 3 FIG. is a schematic diagram of a hydraulic distributed system provided by an embodiment of the present application. 1 represents a main pump, 2 represents a rotor piston pump, 3 represents a one-way valve, 4 represents a left travel motor TL, 5 represents a swing motor SW, 6 represents a main valve, 7 represents a boom cylinder, 8 represents a stick cylinder, 9 represents a bucket cylinder, and 10 represents a right travel motor TR. M1 and M2 represent engines, ARM1 and ARM3 are the stick main flow valves of the two main valves respectively, ARM2 and ARM4 are the stick auxiliary confluence valves of the two main valves respectively, BKT1 and BKT3 are the bucket auxiliary confluence valves of the two main valves respectively, BKT2 and BKT4 are the bucket main flow valves of the two main valves respectively, BOOM1 and BOOM3 are the boom auxiliary confluence valves of the two main valves respectively, BOOM2 and BOOM4 are the boom main flow valves of the two main valves respectively, SW1 and SW2 are the swing valves of the two main valves respectively, TR1 and TR2 are the right travel valves of the two main valves respectively, TL1 and TL2 are the left travel valves of the two main valves respectively, and WS1 and WS2 are the straight travel valves of the two main valves respectively.

[0126] In this embodiment, the boom, stick, and bucket all adopt 4-way spool valves for control, that is, they can be supplied with oil by n (n = 1, 2, 3, 4) rotor piston pumps, and the swing and left and right travels adopt 2-way spool valves for control, that is, they can be supplied with oil by 1-2 rotor piston pumps.

[0127] In this embodiment, the engine configuration can be one of the following two methods:

[0128] Single-engine configuration: Use one engine and connect it to four or more main pumps through a power take-off box.

[0129] Multi-engine configuration: Adopt two or more engines, and each engine is connected to two or more main pumps.

[0130] The number of valve groups of the above main valve can be any value, such as greater than or equal to 4.

[0131] The boom cylinder, stick cylinder, and bucket cylinder are all in the form of double cylinders. The hydraulic system includes components such as the main pump 1, the main valve 6, and each actuator. The hydraulic system is provided with two series-connected main pumps 1, two main valves 6, and two swing motors 5.

[0132] Figure 3Among them, M1 and M2 are engines, and each engine drives a main pump 1 respectively. One main pump 1 consists of two symmetrically arranged rotor piston pumps 2 on the left and right. Specifically, on the connecting oil path between each rotor piston pump 2 and the main valve 6, a check valve 3 is provided to prevent the oil from flowing back when a certain pump is not working, which may cause the pump to reverse and drive the engine to reverse, thus damaging the engine.

[0133] The main valve 6 incorporates valve combinations for controlling various actions. To enable the excavator to perform compound actions, the valve combinations controlling several actions in the main valve 6 are simultaneously connected to the oil outlet of the main pump 1. Specifically, on the main valve 6, there are left and right valve combinations for actions such as the boom (BOOM), arm (ARM), and bucket (BKT), which can achieve flow combination according to requirements to increase the flow rate of the hydraulic cylinder.

[0134] When a certain action needs to be executed, the on-off, flow rate, and flow direction of the hydraulic oil in each valve combination in the main valve 6 are controlled by the joystick, so that the hydraulic oil is output from the main valve 6 to the corresponding actuator to achieve the purpose of executing the action. The actuators in this embodiment include a swing motor 5, a boom cylinder 7, an arm cylinder 8, a bucket cylinder 9, a left travel motor 4, and a right travel motor 10.

[0135] Figure 3 The rotor piston pump 2 therein includes rotor piston pump A, rotor piston pump B, rotor piston pump C, and rotor piston pump D. Rotor piston pump A and rotor piston pump B are in the same main pump, and rotor piston pump C and rotor piston pump D are in the same main pump. In various actions of the excavator, some actions require a large amount of hydraulic oil and need one or more pumps to supply oil simultaneously to be achieved; some actions only require a small amount of hydraulic oil and only need one pump to supply oil to be achieved. On the premise of meeting the action requirements, the power of the pumps not participating in the work is minimized, thereby reducing the energy consumption of the system. It should be noted that the sum of the powers of rotor piston pump A and rotor piston pump B cannot exceed the power provided by the engine M1 to the hydraulic system, and the sum of the powers of rotor piston pump C and rotor piston pump D cannot exceed the power provided by the engine M2 to the hydraulic system. The specific working conditions of each pump during the execution of the action are determined according to the requirements of the action. In this embodiment, the throttle valve is cancelled, and during compound actions, there is no need to limit the flow rate of one action and prioritize the other action.

[0136] When the excavator is operating, generally, four actions such as the boom (BOOM), arm (ARM), bucket (BKT), and swing (SW) are mainly carried out. The following describes the control strategy described in this embodiment in detail through four cases.

[0137] Case 1: When performing a single action, the spools of the valves on both the left and right sides of the main valve 6 can be opened to control the oil supply from n (n = 1, 2, 3, 4) rotor piston pumps. See Table 1 below for details. The specific number of rotor piston pumps to be enabled and the power of the rotor piston pumps are determined according to the requirements of this action, truly achieving supply on demand without wasting energy. In a traditional hydraulic distributed system, a single actuator can only be driven by one rotor piston pump, and other rotor piston pumps cannot supply it with flow; in this embodiment, it can be driven by n (n = 1, 2, 3, 4) rotor piston pumps, and other rotor piston pumps can supply it with flow, thus accelerating the single-action speed.

[0138] Table 1 Working conditions of rotor piston pumps during single action

[0139]

[0140] In the above table, indicates start, indicates stop.

[0141] Case 2: When performing two actions simultaneously, there are 4 working conditions. Rotor piston pump A can supply oil for Action 1, rotor piston pump B can supply oil for Action 2, and rotor piston pumps C and D do not participate in the work; Rotor piston pump A can supply oil for Action 1, rotor piston pumps B and C can supply oil for Action 2, and rotor piston pump D does not participate in the work. At this time, Action 2 should be a high-load action; Rotor piston pump A can supply oil for Action 1, and rotor piston pumps B, C, and D can supply oil for Action 2. At this time, Action 2 should be a high-load action; Rotor piston pumps A and B can supply oil for Action 1, and rotor piston pumps C and D can supply oil for Action 2. See Table 2 below for details. The specific number of rotor piston pumps to be enabled for each action and the power of the rotor piston pumps are determined according to the requirements of these two actions or the actual working conditions, ensuring both speed and controllability without the need for a throttle valve, thus eliminating the energy loss caused by throttling.

[0142] Table 2 Working conditions of rotor piston pumps during two actions

[0143]

[0144] Case 3: When three actions are executed simultaneously, there are 3 working conditions. The rotor piston pump A can supply oil to Action 1, the rotor piston pump B can supply oil to Action 2, the rotor piston pump C can supply oil to Action 3, and the rotor piston pump D does not work. The rotor piston pump A can supply oil to Action 1, the rotor piston pump B can supply oil to Action 2, and the rotor piston pumps C and D can supply oil to Action 3. At this time, Action 3 should be a high-load action. See Table 3 below for details. The specific number of rotor piston pumps enabled for each action and the power of the rotor piston pumps are determined according to the requirements of these three actions or the actual working conditions, ensuring both speed and controllability without energy loss.

[0145] Table 3 Working Conditions of Rotor Piston Pumps in the Case of Three Actions

[0146]

[0147] Case 4: When four actions are executed simultaneously, the rotor piston pumps A, B, C, and D can supply oil to Actions 1, 2, 3, and 4 respectively, with each pump responsible for a single action. See Table 4 below for details. This case is relatively simple. Without considering the number of rotor piston pumps, only by setting the appropriate power of each rotor piston pump can the speed and controllability be ensured.

[0148] Table 4 Working Conditions of Rotor Piston Pumps in the Case of Four Actions

[0149]

[0150] The series-connected piston electronically controlled main pump consists of a front pump (one rotor piston pump) and a rear pump (another rotor piston pump). The power of the front pump and the rear pump can be controlled separately by inputting different current values. The output power of the engine is constant and is distributed to the two rotor piston pumps connected to it. In the traditional case, each rotor piston pump receives the same power, but in the control strategy described in this embodiment, the control system can reasonably distribute the engine output power according to the actual flow requirements of the actions responsible for each rotor piston pump, reducing the power of one pump and increasing the power of the other pump on the premise of constant total power, so as to create a flow difference between the two rotor piston pumps and assist in the reasonable distribution of flow.

[0151] This embodiment will not cause throttling losses and the system is more energy-efficient. When performing a single action, n (n = 1, 2, 3, 4) rotor piston pumps can supply oil to accelerate the speed of the single action. When performing a combined action, the number and power of the oil supply pumps are provided as required, with reasonable distribution, fast speed, and coordinated actions.

[0152] The hydraulic distributed system described in this embodiment takes the dual-engine dual-main pump hydraulic system as an example, but it is not the only embodiment of this control scheme. Other implementation manners based on this patent, such as changing the number of pumps or the number of certain components, should be within the protection scope of this patent. The quantifiers such as "first", "second", etc. described in this patent are only for the convenience of distinction and description, and cannot be understood as indicating or implying their relative importance or implicitly specifying the quantity of the indicated technical features.

[0153] The embodiment of this application also provides a control system for an excavator, which is applied to the controller of the excavator. The excavator further includes an actuator, an engine, a main pump connected to the engine, and a main valve connected to the main pump; a plurality of rotor piston pumps are arranged in the main pump, and a plurality of valve groups are arranged in the main valve. The rotor piston pumps and the valve groups correspond one by one. Each valve group includes a plurality of valve unions, and the valve unions are connected to the corresponding actuators. The control system of the excavator includes:

[0154] An instruction receiving module, configured to receive an operation instruction and determine i to-be-executed actions corresponding to the operation instruction;

[0155] A valve union and pump selection module, configured to determine a target valve union and a target rotor piston pump according to the action type of the to-be-executed action;

[0156] A valve union control module, configured to open all the target valve unions;

[0157] A pump control module, controlling the engine to provide power to all the target rotor piston pumps, so that the target rotor piston pumps deliver hydraulic oil to the corresponding actuators through the target valve unions.

[0158] Further, the process of the valve union and pump selection module determining the target valve union and the target rotor piston pump according to the action type of the to-be-executed action includes: determining a corresponding target actuator according to the action type of the to-be-executed action; setting the valve union connected to the target actuator as the target valve union; setting the rotor piston pump corresponding to the valve group where the target valve union is located as an alternative rotor piston pump; determining the power demand value corresponding to the target actuator, and determining the number of pumps j according to the power demand value; selecting j alternative rotor piston pumps as the target rotor piston pumps.

[0159] Further, the process of the pump control module controlling the engine to provide power to all the target rotor piston pumps includes: calculating the output power of the target rotor piston pumps according to the corresponding relationship between the to-be-executed action and the target rotor piston pumps; controlling the engine to provide power to the corresponding target rotor piston pumps according to the output power.

[0160] Since the embodiments in the system part correspond to those in the method part, please refer to the descriptions of the embodiments in the method part for the embodiments in the system part, which will not be elaborated here.

[0161] This application also provides a storage medium, on which a computer program is stored. When the computer program is executed, the steps provided in the above embodiments can be implemented. The storage medium may include: various media such as USB flash drives, mobile hard disks, read-only memories (ROM), random access memories (RAM), magnetic disks, or optical discs that can store program codes.

[0162] This application also provides an electronic device, which may include a memory and a processor. When the processor calls the computer program stored in the memory, the steps provided in the above embodiments can be implemented. Of course, the electronic device may also include various network interfaces, power supplies and other components.

[0163] The embodiments in the specification are described in a progressive manner. Each embodiment focuses on the differences from other embodiments. The same or similar parts among the embodiments can be referred to each other. For the system disclosed in the embodiments, since it corresponds to the method disclosed in the embodiments, the description is relatively simple. For the relevant parts, please refer to the description in the method part. It should be noted that for those of ordinary skill in the art, without departing from the principle of this application, several improvements and modifications can be made to this application, and these improvements and modifications also fall within the protection scope of this application.

[0164] It should also be noted that in this specification, relational terms such as first and second are only used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any actual relationship or order between these entities or operations. Moreover, the term "comprising", "including" or any other variant thereof is intended to cover non-exclusive inclusion, so that a process, method, article or device including a series of elements not only includes those elements, but also includes other elements not expressly listed, or elements inherent to such process, method, article or device. Without further limitation, an element defined by the statement "including one..." does not exclude the existence of another identical element in the process, method, article or device including the said element.

Claims

1. A control method for an excavator, characterized in that, A controller applied to an excavator, the excavator further comprising an actuator, an engine, a main pump connected to the engine, and a main valve connected to the main pump; a plurality of rotor piston pumps are provided in the main pump, and a plurality of valve connection groups are provided in the main valve, the rotor piston pumps and the valve connection groups are in one-to-one correspondence, each valve connection group includes a plurality of valve connections, and the valve connections are connected to the corresponding actuator. The control method of the excavator includes: Receiving an operation instruction and determining i to-be-executed actions corresponding to the operation instruction; Determining a target valve connection and a target rotor piston pump according to the action type of the to-be-executed action; Opening all the target valve connections; Controlling the engine to supply power to all the target rotor piston pumps, so that the target rotor piston pumps deliver hydraulic oil to the corresponding actuators through the target valve connections.

2. The control method of the excavator according to claim 1, characterized in that Determining a target valve connection and a target rotor piston pump according to the action type of the to-be-executed action includes: Determining a corresponding target actuator according to the action type of the to-be-executed action; Setting the valve connection connected to the target actuator as the target valve connection; Setting the rotor piston pump corresponding to the valve connection group where the target valve connection is located as an alternative rotor piston pump; Determining a power demand value corresponding to the target actuator, and determining the number of pumps j according to the power demand value; Selecting j alternative rotor piston pumps as the target rotor piston pumps.

3. The control method of the excavator according to claim 1, wherein Controlling the engine to supply power to all the target rotor piston pumps includes: Calculating the output power of the target rotor piston pumps according to the corresponding relationship between the to-be-executed action and the target rotor piston pumps; Controlling the engine to supply power to the corresponding target rotor piston pumps according to the output power.

4. A control system for an excavator, characterized in that, A controller applied to an excavator, the excavator further comprising an actuator, an engine, a main pump connected to the engine, and a main valve connected to the main pump; a plurality of rotor piston pumps are provided in the main pump, and a plurality of valve connection groups are provided in the main valve, the rotor piston pumps and the valve connection groups are in one-to-one correspondence, each valve connection group includes a plurality of valve connections, and the valve connections are connected to the corresponding actuator. The control system of the excavator includes: An instruction receiving module, configured to receive an operation instruction and determine i to-be-executed actions corresponding to the operation instruction; A valve connection and pump selection module, configured to determine a target valve connection and a target rotor piston pump according to the action type of the to-be-executed action; A valve connection control module, configured to open all the target valve connections; A pump control module, controlling the engine to supply power to all the target rotor piston pumps, so that the target rotor piston pumps deliver hydraulic oil to the corresponding actuators through the target valve connections.

5. An excavator, characterized in that, The excavator includes a controller, an actuator, an engine, a main pump connected to the engine, and a main valve connected to the main pump; a plurality of rotor piston pumps are provided in the main pump, and a plurality of valve connection groups are provided in the main valve, the rotor piston pumps and the valve connection groups are in one-to-one correspondence, each valve connection group includes a plurality of valve connections, and the valve connections are connected to the corresponding actuator; The operations performed by the controller during operation include: Receiving an operation instruction and determining i to-be-executed actions corresponding to the operation instruction; Determine the target valve bank and the target rotor piston pump according to the action type of the action to be executed; Open all the target valve banks; Control the engine to supply power to all the target rotor piston pumps, so that the target rotor piston pumps deliver hydraulic oil to the corresponding actuators through the target valve banks.

6. The excavator according to claim 5, wherein, The rotor piston pump is connected to the corresponding valve bank group through an output pipeline, and a check valve is arranged on the output pipeline.

7. The excavator according to claim 5, wherein The excavator includes a first engine, a second engine, a first main pump, a second main pump, a first main valve and a second main valve; The first engine is connected to the first main pump, and N rotor piston pumps are arranged in the first main pump; the second engine is connected to the second main pump, and M rotor piston pumps are arranged in the second main pump; The first main valve includes N valve bank groups, and the valve bank groups in the first main valve correspond one by one to the rotor piston pumps in the first main pump; the second main valve includes M valve bank groups, and the valve bank groups in the second main valve correspond one by one to the rotor piston pumps in the second main pump.

8. The excavator according to claim 7, wherein A first rotor piston pump and a second rotor piston pump are arranged in the first main pump, and a third rotor piston pump and a fourth rotor piston pump are arranged in the second main pump; The first main valve includes a first valve bank group and a second valve bank group; The second main valve includes a third valve bank group and a fourth valve bank group; The first rotor piston pump is connected to the first valve bank group through an output pipeline, the second rotor piston pump is connected to the second valve bank group through an output pipeline, the third rotor piston pump is connected to the third valve bank group through an output pipeline, and the fourth rotor piston pump is connected to the fourth valve bank group through an output pipeline.

9. The excavator according to claim 7, wherein, The valve banks in the valve bank group include: A boom main flow valve bank and a boom auxiliary confluence valve bank connected to the boom cylinder; A bucket main flow valve bank and a bucket auxiliary confluence valve bank connected to the bucket cylinder; A boom main flow valve bank and a boom auxiliary confluence valve bank connected to the boom cylinder; A swing valve bank connected to the swing motor; A left travel valve bank connected to the left travel motor; A right travel valve bank connected to the right travel motor; A straight travel valve bank connected to the left travel motor and the right travel motor respectively.

10. The excavator according to claim 5, wherein, The rotor piston pumps in the main pump are connected in series.

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