Excavator control method and device and excavator

Abstract

The invention discloses an excavator control method and device and an excavator, and the excavator comprises a first control loop which at least comprises a movable arm motor, a movable arm pump, a first hydraulic valve and a movable arm; the second control loop at least comprises a bucket rod motor, a bucket rod pump, a second hydraulic valve and a bucket rod; the control method comprises the steps that opening information of a handle on the excavator is obtained; according to the opening degree information, the flow demand of the movable arm pump and / or the flow demand of the bucket rod pump are / is determined; the rotating speed requirement of a movable arm motor and / or the rotating speed requirement of a bucket rod motor are / is determined according to the flow requirement of the movable arm pump and / or the flow requirement of the bucket rod pump; and the rotating speed requirement of the movable arm motor and / or the rotating speed requirement of the bucket rod motor are / is sent to a motor controller of the excavator so as to control the excavator. According to the control method provided by the invention, the movable arm, the bucket rod and the like are mutually independent, so that the energy loss during composite action is avoided, the speed matching of the excavator is realized by controlling the rotating speed of the motor, and the user experience is improved.

Description

Technical Field

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

[0002] During the operation of a traditional hydraulic excavator in compound operations (such as leveling the ground), due to different loads for different operations, in order to achieve speed matching between various operations, it is necessary to limit the opening degree of the main spool valve of the operation with a small load or perform throttle compensation on the side with a small load through a priority valve. However, the cost of doing so is the generation of throttle losses and the waste of energy. And this kind of waste is inevitable in traditional hydraulic excavators.

[0003] For example, a common leveling operation on an excavator is the action combination of the stick in and the boom up. Most of the time during leveling, due to the self-weight of the stick, the stick in is a negative load, and for the boom up, because it needs to overcome the huge self-weight of the working mechanism, the load pressure is relatively high. In order to ensure the leveling process, especially the rapid movement of the boom at the initial stage of leveling without digging pits, it is necessary to impose a large throttle restriction on the stick, so that the stick that originally does not require power output also has to build up the pressure to a relatively high value, and the energy waste is obvious. Summary of the Invention

[0004] The present invention provides a control method, device and excavator for an excavator. On the one hand, through a distributed solution (separating the boom and stick control circuits), the boom and stick of the excavator are made independent of each other, thus eliminating the problem of energy loss caused by throttling the low load to achieve speed matching during compound operations. On the other hand, through the control of the motor speed, the speed matching during leveling is achieved, enhancing the user's driving experience.

[0005] According to a first aspect of the present invention, there is provided a control method for an excavator, the excavator including a first control circuit and a second control circuit; the first control circuit at least includes: a boom motor, a boom pump, a first hydraulic valve and a boom; the second control circuit at least includes: a stick motor, a stick pump, a second hydraulic valve and a stick; the output end of the boom motor is connected to the boom pump, and the boom motor drives the boom pump to control the valve opening degree of the first hydraulic valve to realize the rise or fall of the boom; the output end of the stick motor is connected to the stick pump, and the stick motor drives the stick pump to control the valve opening degree of the second hydraulic valve to realize the retraction or extension of the stick; wherein, both the boom pump and the stick pump are hydraulic pumps;

[0006] The control method includes:

[0007] Obtain the opening degree information of the handle on the excavator;

[0008] Determine the flow demand of the boom pump and / or the flow demand of the stick pump according to the opening information;

[0009] Determine the rotational speed demand of the boom motor and / or the rotational speed demand of the stick motor according to the flow demand of the boom pump and / or the flow demand of the stick pump;

[0010] Send the rotational speed demand of the boom motor and / or the rotational speed demand of the stick motor to the motor controller of the excavator to control the excavator.

[0011] Optionally, determining the rotational speed demand of the boom motor and / or the rotational speed demand of the stick motor according to the flow demand of the boom pump and / or the flow demand of the stick pump further includes:

[0012] Obtain the working condition of the excavator;

[0013] Determine the calculation method of the rotational speed demand of the motor corresponding to the excavator according to the working condition.

[0014] Optionally, obtaining the working condition of the excavator includes:

[0015] Obtain the opening of the boom handle and the opening of the stick handle;

[0016] When the opening of the boom handle and the opening of the stick handle are both greater than or equal to the first threshold, it is determined that the working condition of the excavator is the flat ground working condition;

[0017] When one of the opening of the boom handle and the opening of the stick handle is 0 and the other is greater than or equal to the second threshold, it is determined that the working condition of the excavator is the single-action working condition.

[0018] Optionally, the calculation method of determining the rotational speed demand of the motor corresponding to the excavator according to the working condition includes:

[0019] When the working condition is the single-action working condition, obtain the opening information of the single-action handle and the displacement of the hydraulic pump for the single-action;

[0020] Determine the flow demand of the hydraulic pump corresponding to the single-action according to the opening information;

[0021] Determine the rotational speed demand of the motor corresponding to the single-action according to the flow demand of the hydraulic pump corresponding to the single-action and the displacement of the hydraulic pump.

[0022] Optionally, the calculation method of determining the rotational speed demand of the motor corresponding to the excavator according to the working condition includes:

[0023] When the working condition is the flat ground working condition, obtain the opening of the boom handle and the opening of the stick handle;

[0024] Determine the lifting / falling flow demand of the boom pump and the retracting / extending flow demand of the stick pump according to the opening degree of the boom handle and the opening degree of the stick handle respectively;

[0025] Determine the motor speed demand of the boom according to the lifting / falling flow demand of the boom pump and the displacement of the boom pump;

[0026] Determine the motor speed demand of the stick according to the retracting / extending flow demand of the stick pump and the displacement of the stick pump.

[0027] Optionally, after obtaining the opening degree of the boom handle and the opening degree of the stick handle, it further includes:

[0028] Determine a first limiting coefficient according to the opening degree of the boom handle;

[0029] Determine the lifting flow demand of the boom according to the first limiting coefficient and the maximum lifting flow demand of the boom; wherein, the maximum lifting flow demand of the boom pump decreases as the time of the excavator in the flat working condition increases.

[0030] Optionally, the motor speed demand of the boom and the motor speed demand of the stick are calculated by formula (1):

[0031]

[0032] Wherein, n is the motor speed demand of the boom or the motor speed demand of the stick, Q is the lifting flow demand or the retracting flow demand, and q is the displacement of the boom hydraulic pump or the displacement of the stick hydraulic pump.

[0033] Optionally, the stick further includes a first chamber and a second chamber, and the pressure-receiving area of the first chamber is smaller than the pressure-receiving area of the second chamber; after the working condition is the flat working condition, it further includes:

[0034] Obtain the pressure of the first chamber and the pressure of the second chamber of the stick;

[0035] Determine the pressure difference of the stick according to the pressure of the first chamber and the pressure of the second chamber;

[0036] Determine the lifting rate of the boom according to the pressure difference.

[0037] According to a second aspect of the present invention, there is provided a control device for an excavator, the excavator including a first control circuit and a second control circuit; the first control circuit at least includes: a boom motor, a boom pump, a first hydraulic valve, and a boom; the second control circuit at least includes: a stick motor, a stick pump, a second hydraulic valve, and a stick; an output end of the boom motor is connected to the boom pump, and the boom motor drives the boom pump to control an opening degree of the first hydraulic valve to realize rising or falling of the boom; an output end of the stick motor is connected to the stick pump, and the stick motor drives the stick pump to control an opening degree of the second hydraulic valve to realize retraction or extension of the stick; wherein, both the boom pump and the stick pump are hydraulic pumps; the control device includes:

[0038] An opening degree acquisition module, configured to acquire opening degree information of a handle;

[0039] A flow rate demand determination module, configured to determine a flow rate demand of the boom pump and / or a flow rate demand of the stick pump according to the opening degree information;

[0040] A rotation speed demand determination module, configured to determine a rotation speed demand of the boom motor and / or a rotation speed demand of the stick motor according to the flow rate demand of the boom pump and / or the flow rate demand of the stick pump;

[0041] An execution module, configured to send the rotation speed demand of the boom motor and / or the rotation speed demand of the stick motor to a motor controller of the excavator to control the excavator.

[0042] According to a third aspect of the present invention, there is provided an excavator, including the control device for an excavator described in the second aspect of the present invention.

[0043] The present invention discloses a control method for an excavator. The excavator includes a first control circuit and a second control circuit. The first control circuit at least includes: a boom motor, a boom pump, a first hydraulic valve, and a boom. The second control circuit at least includes: a stick motor, a stick pump, a second hydraulic valve, and a stick. The output end of the boom motor is connected to the boom pump, and the boom motor drives the boom pump to control the valve opening of the first hydraulic valve to achieve the rise or fall of the boom. The output end of the stick motor is connected to the stick pump, and the stick motor drives the stick pump to control the valve opening of the second hydraulic valve to achieve the retraction or extension of the stick. The stick further includes a first chamber and a second chamber, and the pressure-receiving area of the first chamber is smaller than that of the second chamber. Wherein, both the boom pump and the stick pump are hydraulic pumps. The control method includes: obtaining the opening information of the handle on the excavator; determining the flow demand of the boom pump and / or the flow demand of the stick pump according to the opening information; determining the rotational speed demand of the boom motor and / or the rotational speed demand of the stick motor according to the flow demand of the boom pump and / or the flow demand of the stick pump; sending the rotational speed demand of the boom motor and / or the rotational speed demand of the stick motor to the motor controller of the excavator to control the excavator. The control method for the excavator provided by the present invention, on the one hand, through a distributed solution (separating the boom and stick control circuits), makes the boom and stick of the excavator independent of each other, thus eliminating the energy loss problem caused by throttling the low load to achieve speed matching during compound actions. On the other hand, through the control of the motor rotational speed, the speed matching during leveling is achieved, improving the user's driving experience.

[0044] It should be understood that the content described in this part is not intended to identify the key or important features of the embodiments of the present invention, nor is it used to limit the scope of the present invention. Other features of the present invention will become easily understood through the following description. BRIEF DESCRIPTION OF THE DRAWINGS

[0045] In order to more clearly illustrate the technical solutions in the embodiments of the present invention, the following will briefly introduce the drawings required for the description of the embodiments. Obviously, the drawings in the following description are only some embodiments of the present invention. For those of ordinary skill in the art, without creative efforts, other drawings can be obtained based on these drawings.

[0046] Figure 1 It is a schematic diagram of the control principle of the excavator provided by the embodiment of the present invention;

[0047] Figure 2 It is a flowchart of a control method for an excavator provided by an embodiment of the present invention;

[0048] Figure 3 It is a flowchart of another control method for an excavator provided by an embodiment of the present invention;

[0049] Figure 4Another flowchart of the control method for an excavator provided by an embodiment of the present invention;

[0050] Figure 5 Another flowchart of the control method for an excavator provided by an embodiment of the present invention;

[0051] Figure 6 Another flowchart of the control method for an excavator provided by an embodiment of the present invention;

[0052] Figure 7 Another flowchart of the control method for an excavator provided by an embodiment of the present invention;

[0053] Figure 8 It is a schematic diagram of the grading working condition of an excavator provided by an embodiment of the present invention;

[0054] Figure 9 Another flowchart of the control method for an excavator provided by an embodiment of the present invention;

[0055] Figure 10 It is a schematic structural diagram of a control device for an excavator provided by an embodiment of the present invention. Detailed implementation manners

[0056] In order to enable those skilled in the art to better understand the solution of the present invention, the technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative efforts shall fall within the protection scope of the present invention.

[0057] It should be noted that the terms "first", "second", etc. in the specification and claims of the present invention and the above-mentioned drawings are used to distinguish similar objects, and do not necessarily need to describe a specific order or sequence. It should be understood that such used data can be interchanged under appropriate circumstances so that the embodiments of the present invention described here can be implemented in an order different from those illustrated or described here. In addition, the terms "include" and "have" and any variations thereof are intended to cover non-exclusive inclusion. For example, a process, method, system, product or device including a series of steps or units does not necessarily have to be limited to those clearly listed steps or units, but may include other steps or units not clearly listed or inherent to these processes, methods, products or devices.

[0058] It should be understood that various forms of the process shown above can be used, with steps reordered, added, or deleted. For example, the steps described in the present invention can be executed in parallel, sequentially, or in a different order, as long as the desired results of the technical solution of the present invention can be achieved, and no limitation is imposed herein.

[0059] Figure 1 is a schematic diagram of the control principle of an excavator provided by an embodiment of the present invention. Refer to Figure 1 , an excavator provided by an embodiment of the present invention includes a first control loop A and a second control loop B. The first control loop A at least includes: a boom motor 1, a boom pump 2, a first hydraulic valve 3, and a boom 4; the output end of the boom motor 1 is connected to the boom pump 2. The boom motor 1 obtains a control signal issued by the motor controller 10, controls the boom pump 2 to provide flow to the first hydraulic valve 3 to control the opening degree of the first hydraulic valve 3, and realizes the rise or fall of the excavator boom 4 through the opening degree of the first hydraulic valve 3; the second control loop B at least includes: a stick motor 5, a stick pump 6, a second hydraulic valve 7, and a stick 8; the output end of the stick motor 5 is connected to the stick pump 6. The stick motor 5 obtains a control signal issued by the motor controller 10, controls the stick pump 6 to provide flow to the second hydraulic valve 7 to control the opening degree of the second hydraulic valve 7, and realizes the retraction or extension of the excavator stick 8 through the opening degree of the second hydraulic valve 7; wherein, both the boom pump 2 and the stick pump 6 are hydraulic pumps. The first control loop A adopts a closed hydraulic circuit, and the boom pump 2 is driven alone by a boom motor 1. The boom pump 2 is a fixed-displacement pump. The flow required for the rise or fall of the boom 4 is realized by adjusting the speed of the boom motor 1 in real time, while the stick 8 still uses a traditional hydraulic valve (i.e., the second hydraulic valve 7) for flow distribution; the excavator further includes: a motor controller 10 and a vehicle controller 11, and the vehicle controller 11 and the motor controller 10 are electrically connected; a battery 9 is used to supply power to the motor. Figure 2 A flowchart of a control method for an excavator provided by an embodiment of the present invention. Refer to Figure 2 Refer to Figure 1 and Figure 2 , the control method of the excavator provided by an embodiment of the present invention includes:

[0060] S100. Obtain the opening degree information of the handle on the excavator.

[0061] Specifically, the vehicle controller 11 obtains the opening degree information of the handle 9, and the opening degree information of the handle 9 is determined by the operation intention of the driver in the cab.

[0062] S101. Determine the flow rate requirements of the boom pump and / or the stick pump according to the opening information. Specifically, determine the flow rate requirements of the boom pump 2 and / or the stick pump 6 according to the opening information (i.e., the operation instructions input by the driver). Generally, the larger the opening, the greater the flow rate required by the pump. For example, when the driver operates the boom handle with an opening of 20%, the flow rate required by the boom pump 2 is 20 L / min. When the driver operates the boom handle with an opening of 80%, the flow rate required by the boom pump 2 is 80 L / min. Or, when the opening of the stick handle is 50% plus the opening of the boom handle is 30%, it means that the flow rate required by the stick pump 5 is 50 L / min, and the flow rate required by the boom pump 2 is 30 L / min.

[0063] S102. Determine the rotational speed requirements of the boom motor and / or the stick motor according to the flow rate requirements of the boom pump and / or the stick pump.

[0064] Specifically, after determining the flow rate requirements of the boom pump and / or the stick pump in step S101, determine the rotational speed requirements of the corresponding motor according to the flow rate requirements. For example, when the determined flow rate required by the boom pump 2 is 40 L / min, the rotational speed required by the boom motor 1 is 869 rpm, so that the boom pump 2 has enough flow rate to support the rise or fall of the boom 4.

[0065] S103. Send the rotational speed requirements of the boom motor and / or the stick motor to the motor controller of the excavator to control the excavator.

[0066] Specifically, after determining the rotational speed requirements of the boom motor and / or the stick motor in step S102 above, the vehicle controller 11 transmits the rotational speed requirements to the motor controller 10. The motor controller 10 sends them to their respective corresponding motors (such as the boom motor 1 or the stick motor 5) according to their respective rotational speed requirements, and the motor controls the hydraulic valve to control the excavator.

[0067] For the control method of the excavator provided by the embodiment of the present invention, on the one hand, through a distributed solution (separating the boom and stick control circuits), the boom and stick of the excavator are independent of each other, thus eliminating the energy loss problem caused by throttling the low load to achieve speed matching during compound actions. On the other hand, through the control of the motor rotational speed, the speed matching during leveling is achieved, improving the user's driving experience.

[0068] Optionally, Figure 3 Another flow chart of the control method of the excavator provided by the embodiment of the present invention, refer to Figure 3, the embodiments of the present invention further refine the determination of the rotational speed requirements of the boom motor and / or the stick motor based on the flow rate requirements of the boom pump and / or the stick pump. The control method for an excavator provided by the embodiments of the present invention includes:

[0069] S200. Obtain the opening degree information of the handle on the excavator.

[0070] S201. Determine the flow rate requirements of the boom pump and / or the stick pump based on the opening degree information.

[0071] S202. Obtain the working condition of the excavator.

[0072] Specifically, the vehicle controller 11 obtains the operation of the driver's operation handle, and obtains the working condition of the excavator according to the operation of the driver's operation handle. The working condition is the specific operation action that the driver controls the excavator to perform.

[0073] S203. Determine the calculation method for the rotational speed requirements of the corresponding motor of the excavator according to the working condition.

[0074] Specifically, according to the working condition of the excavator determined in step S202 above, different calculation methods are selected to calculate the rotational speed requirements of the corresponding motor. For example, in the single-action working condition or the flat-ground working condition, the flat-ground working condition is a typical working condition for medium and small-tonnage excavators, mainly including two actions: boom lifting and stick inhauling. When the driver operates, generally, the stick and the bucket are first turned outwards to a relatively outer position, and the boom is lowered so that the tip of the bucket teeth is placed near the ground to be leveled, and then the boom lifting and the stick inhauling are operated simultaneously. The goal is to make the tip of the bucket teeth sweep along the ground plane of the initial position to level the ground.

[0075] S204. Send the rotational speed requirements of the boom motor and / or the stick motor to the motor controller of the excavator to control the excavator.

[0076] Optionally, Figure 4 Another flow chart of the control method for an excavator provided by the embodiments of the present invention, refer to Figure 4 , the embodiments of the present invention further refine the obtaining of the working condition of the excavator. The control method for an excavator provided by the embodiments of the present invention includes:

[0077] S300. Obtain the opening degree information of the handle on the excavator.

[0078] S301. Determine the flow rate requirements of the boom pump and / or the stick pump based on the opening degree information.

[0079] S302. Obtain the opening degree of the boom handle and the opening degree of the stick handle.

[0080] Specifically, the vehicle controller 11 acquires the opening information of the boom handle and the stick handle in the cab respectively, and compares the opening of the boom handle and the opening of the stick handle with a first threshold value.

[0081] S3021. When the opening of the boom handle and the opening of the stick handle are both greater than or equal to the first threshold value, it is determined that the working condition of the excavator is the flat ground working condition.

[0082] Specifically, when the opening of the boom handle and the opening of the stick handle are both greater than or equal to the first threshold value (for example, 60%), it proves that the driver wants to start the operations of the boom and the stick simultaneously, and at this time, it can be determined that the working condition to be executed by the excavator is the flat ground working condition.

[0083] S3022. When one of the opening of the boom handle and the opening of the stick handle is 0 and the other is greater than or equal to a second threshold value, it is determined that the working condition of the excavator is the single-action working condition.

[0084] Specifically, when the opening of the boom handle is 0 (i.e., it indicates that the driver does not want to execute the operation of the boom) and the opening of the stick handle is greater than or equal to the second threshold value (for example, 55%), or when the opening of the stick handle is 0 (i.e., it indicates that the driver does not want to execute the operation of the stick) and the opening of the boom handle is greater than or equal to the second threshold value (for example, 55%), it is determined that the working condition of the excavator is the single-action working condition (i.e., only the boom is raised or lowered, or only the stick is retracted or extended).

[0085] S303. Determine the calculation method of the motor speed demand corresponding to the excavator according to the working condition.

[0086] S304. Send the speed demand of the boom motor and / or the speed demand of the stick motor to the motor controller of the excavator to control the excavator.

[0087] Optionally, Figure 5 Another flow chart of the control method of the excavator provided by the embodiment of the present invention is referred to Figure 5 , and the embodiment of the present invention further refines the calculation method of the motor speed demand corresponding to the excavator according to the working condition. The control method of the excavator provided by the embodiment of the present invention includes:

[0088] S400. Acquire the opening information of the handle on the excavator.

[0089] S401. Determine the flow demand of the boom pump and / or the flow demand of the stick pump according to the opening information.

[0090] S402. Acquire the working condition of the excavator.

[0091] S403. When the working condition is the single-action working condition, acquire the opening information of the single-action handle and the displacement of the single-action hydraulic pump.

[0092] Specifically, when it is determined in step S402 that the working condition of the excavator is a single-action working condition, the opening information of the single-action handle (i.e., the boom handle or the stick handle) and the hydraulic pump displacement of the single action (i.e., the boom pump 2 or the stick pump 6) are obtained. Among them, the hydraulic pump displacement can be obtained by the whole machine controller 11.

[0093] S404. Determine the flow demand of the hydraulic pump corresponding to the single action according to the opening information.

[0094] Specifically, according to the opening information (i.e., the opening of the handle operated by the driver, for example, the opening of the boom handle is 30% or the opening of the stick handle is 60%), the flow demand of the hydraulic pump (i.e., the boom pump 2 or the stick pump 6) corresponding to the single action (for example, only the boom rises or the stick retracts) is determined.

[0095] S405. Determine the motor speed demand corresponding to the single action according to the flow demand of the hydraulic pump corresponding to the single action and the hydraulic pump displacement.

[0096] Specifically, according to the flow demand of the hydraulic pump corresponding to the single action determined in step S404 above and the hydraulic pump displacement determined in step S403 above, the motor speed demand of the motor (for example, the boom motor 1 or the stick motor 5) corresponding to the single action is calculated.

[0097] S406. Send the speed demand of the boom motor and / or the speed demand of the stick motor to the motor controller of the excavator to control the excavator.

[0098] Optionally, Figure 6 Another flow chart of the control method of the excavator provided by the embodiment of the present invention is referred to Figure 6 , and the embodiment of the present invention further refines the calculation method for determining the motor speed demand corresponding to the excavator according to the working condition. The control method of the excavator provided by the embodiment of the present invention includes:

[0099] S500. Obtain the opening information of the handle on the excavator.

[0100] S501. Determine the flow demand of the boom pump and / or the flow demand of the stick pump according to the opening information.

[0101] S502. Obtain the working condition of the excavator.

[0102] S503. When the working condition is a flat ground working condition, obtain the opening of the boom handle and the opening of the stick handle.

[0103] Specifically, after the working condition of the excavator is determined in step S502 above, when the working condition is a flat ground working condition, the opening of the boom handle and the opening of the stick handle are obtained simultaneously through the whole vehicle controller 11.

[0104] S504. Determine the lifting / lowering flow rate requirements of the boom pump and the retracting / extending flow rate requirements of the arm pump respectively according to the opening degrees of the boom handle and the arm handle.

[0105] Specifically, since the operation of the boom can be boom lifting or boom lowering, and the operation of the arm can be arm retracting or arm extending, therefore, determine the flow rate requirements for the boom pump to lift / lower according to the opening degree of the boom handle, and determine the flow rate requirements for the arm pump to retract / extend according to the opening degree of the arm handle.

[0106] S505. Determine the motor speed requirements of the boom according to the lifting / lowering flow rate requirements of the boom pump and the displacement of the boom pump.

[0107] Specifically, after determining the lifting / lowering flow rate requirements of the boom pump in the above step S504, determine the motor speed requirements of the boom according to the flow rate requirements of the boom pump.

[0108] S506. Determine the motor speed requirements of the arm according to the retracting / extending flow rate requirements of the arm pump and the displacement of the arm pump.

[0109] Specifically, after determining the retracting / extending flow rate requirements of the arm pump in the above step S504, determine the motor speed requirements of the arm according to the flow rate requirements of the arm pump.

[0110] S507. Send the motor speed requirements of the boom motor and / or the motor speed requirements of the arm motor to the motor controller of the excavator to control the excavator.

[0111] Figure 7 Another flow chart of the control method for an excavator provided by an embodiment of the present invention, refer to Figure 7 , Optionally, after obtaining the opening degrees of the boom handle and the arm handle, it further includes:

[0112] S600. Determine the first limiting coefficient according to the opening degree of the boom handle.

[0113] Specifically, obtain the opening degree of the boom handle through the vehicle controller 11, and determine the first limiting coefficient according to the opening degree of the boom handle. Exemplarily, when the opening degree of the boom handle is 50%, the first limiting coefficient can be 50% to limit the lifting / lowering speed of the boom. Among them, the determination of the first limiting coefficient can be determined through a table of opening degree - first limiting coefficient established through a large number of experiments.

[0114] S601. Determine the lifting flow rate requirements of the boom according to the first limiting coefficient and the maximum lifting flow rate requirements of the boom; wherein, the maximum lifting flow rate requirements of the boom pump decrease with the increase of the time when the excavator is in the flat working condition.

[0115] Specifically, the maximum lifting flow demand of the boom refers to the maximum flow demand that can be achieved by the preset upward / downward movement of the boom. The lifting flow demand of the boom is determined based on the first limiting coefficient and the maximum lifting flow demand of the boom. Exemplarily, when the first limiting coefficient is 0.5 and the maximum lifting flow demand of the boom is 200 L / min, the determined lifting flow demand of the boom is 100 L / min. At the same time, Figure 8 is a schematic diagram of the grading working condition of an excavator provided by an embodiment of the present invention. Refer to Figure 8 , and the initial time when the excavator is in the grading working condition is also obtained (the grading working condition is the Figure 8 process from C to D shown in the figure, in which the boom 4 is lifted while the stick 8 is retracted). In the initial stage of grading, the boom cylinder needs to overcome the self-weight of each mechanism when lifting, with a large load. However, the retraction of the stick is affected by the self-weight of the mechanism, and the load is negative or very small. In addition, in order to save energy, regeneration is usually designed in the main valve for the retraction of the stick. Affected by the load difference and the regeneration flow, the retraction of the stick often responds faster at this time, resulting in the initial speed of the stick retraction being faster than the boom lifting speed, leading to the so-called grading pitting (also known as nodding) phenomenon. Therefore, as time passes when the excavator is in the initial time of the grading working condition, the maximum lifting flow demand of the boom pump is reduced to avoid the occurrence of the grading pitting (nodding) phenomenon.

[0116] Optionally, the motor speed demand of the boom and the motor speed demand of the stick are calculated by formula (1):

[0117]

[0118] where n is the motor speed demand of the boom or the motor speed demand of the stick, Q is the lifting flow demand or the retraction flow demand, and q is the displacement of the hydraulic pump of the boom or the displacement of the hydraulic pump of the stick.

[0119] Optionally, Figure 9 is a schematic diagram of the grading working condition of an excavator provided by an embodiment of the present invention. Refer to Figure 9 , refer to Figure 1 and Figure 9 , the stick 8 further includes: a first chamber ( Figure 1 not shown in the figure) and a second chamber ( Figure 1 not shown in the figure). The pressure-receiving area of the first chamber is smaller than the pressure-receiving area of the second chamber, that is, the first chamber is the small chamber on the stick 8, and the second chamber is the large chamber on the stick 8. The control method of the excavator provided by the embodiment of the present invention includes:

[0120] S700. Obtain the pressure of the first chamber and the pressure of the second chamber of the stick.

[0121] Since the bucket arm retraction has regeneration, and the higher the pressure in the small chamber of the bucket arm, the more the regeneration flow rate will be, so it will lead to the more serious the gouging phenomenon if the bucket arm extends farther at the initial stage of grading. On the other hand, at the initial stage of grading, the farther away it is, the faster the boom is required to move from the perspective of speed matching. Therefore, the control method provided by the embodiment of the present invention takes into account the flow rate distribution problem at the initial stage of grading, and obtains the pressure of the first chamber and the second chamber of the bucket arm at the initial stage of grading.

[0122] S701. Determine the pressure difference of the bucket arm according to the pressure of the first chamber and the second chamber.

[0123] Specifically, the pressure difference = the pressure of the first chamber - the pressure of the second chamber. Pressure sensors are respectively installed in the small chamber (the first chamber) and the large chamber (the second chamber) of the bucket arm cylinder to record the instantaneous pressure difference when the excavator starts grading (that is, the difference between the pressure of the first chamber and the pressure of the second chamber).

[0124] S702. Determine the lifting rate of the boom according to the pressure difference.

[0125] Specifically, considering the operating experience of the driver, it is necessary to perform a ramp processing after calculating the rotational speed requirement of the boom motor and / or the rotational speed requirement of the bucket arm motor. Ramp Handling refers to the gradual adjustment of the control signal (such as the motor speed requirement command, etc.) to avoid sudden step changes, so as to ensure the smoothness of the action, reduce the impact, and protect the hydraulic and mechanical systems. Determine the lifting rate of the boom (that is, the ramp slope of the boom) according to the pressure difference determined in the above step S701. Generally, the greater the pressure difference, the faster the ramp (that is, the faster the lifting speed of the boom).

[0126] According to the same inventive concept, Figure 10 is a schematic structural diagram of a control device of an excavator provided by an embodiment of the present invention. Refer to Figure 10 , an embodiment of the present invention further provides a control device of an excavator. The excavator includes a first control loop and a second control loop; the first control loop at least includes: a boom motor, a boom pump, a first hydraulic valve, and a boom; the second control loop at least includes: a bucket arm motor, a bucket arm pump, a second hydraulic valve, and a bucket arm; the output end of the boom motor is connected to the boom pump, and the boom motor drives the boom pump to control the valve opening of the first hydraulic valve to realize the rise or fall of the boom; the output end of the bucket arm motor is connected to the bucket arm pump, and the bucket arm motor drives the bucket arm pump to control the valve opening of the second hydraulic valve to realize the retraction or extension of the bucket arm; wherein, both the boom pump and the bucket arm pump are hydraulic pumps; the control device includes:

[0127] An opening acquisition module 101, configured to acquire the opening information of the handle;

[0128] The flow demand determination module 102 is configured to determine the flow demand of the boom pump and / or the flow demand of the stick pump according to the opening information;

[0129] The rotational speed demand determination module 103 is configured to determine the rotational speed demand of the boom motor and / or the rotational speed demand of the stick motor according to the flow demand of the boom pump and / or the flow demand of the stick pump;

[0130] The execution module 104 is configured to send the rotational speed demand of the boom motor and / or the rotational speed demand of the stick motor to the motor controller of the excavator to control the excavator.

[0131] The control device of an excavator provided by an embodiment of the present invention can achieve the same technical effects as the control method of an excavator provided by the above-mentioned embodiment of the invention, and details are not described herein again.

[0132] According to the same inventive concept, an embodiment of the present invention provides an excavator, including the control device of the excavator in the above-mentioned embodiment of the invention.

[0133] The excavator provided by an embodiment of the present invention can achieve the same technical effects as the control device of an excavator provided by the above-mentioned embodiment of the invention, and details are not described herein again.

[0134] The above specific embodiments do not constitute a limitation on the protection scope of the present invention. Those skilled in the art should understand that various modifications, combinations, sub-combinations and substitutions can be made according to design requirements and other factors. Any modifications, equivalent substitutions and improvements made within the spirit and principle of the present invention shall be included within the protection scope of the present invention.

Claims

1. A control method for an excavator, characterized in that The excavator includes a first control circuit and a second control circuit; the first control circuit at least includes: a boom motor, a boom pump, a first hydraulic valve, and a boom; the second control circuit at least includes: a stick motor, a stick pump, a second hydraulic valve, and a stick; the output end of the boom motor is connected to the boom pump, and the boom motor drives the boom pump to control the valve opening of the first hydraulic valve to realize the rise or fall of the boom; the output end of the stick motor is connected to the stick pump, and the stick motor drives the stick pump to control the valve opening of the second hydraulic valve to realize the retraction or extension of the stick; wherein, both the boom pump and the stick pump are hydraulic pumps; The control method includes: Obtaining the opening information of the handle on the excavator; Determining the flow demand of the boom pump and / or the flow demand of the stick pump according to the opening information; Determining the rotational speed demand of the boom motor and / or the rotational speed demand of the stick motor according to the flow demand of the boom pump and / or the flow demand of the stick pump; Sending the rotational speed demand of the boom motor and / or the rotational speed demand of the stick motor to the motor controller of the excavator to control the excavator.

2. The control method of the excavator according to claim 1, characterized in that, Determining the rotational speed demand of the boom motor and / or the rotational speed demand of the stick motor according to the flow demand of the boom pump and / or the flow demand of the stick pump further includes: Obtaining the working condition of the excavator; Determining the calculation method of the motor speed demand corresponding to the excavator according to the working condition.

3. The control method of the excavator according to claim 2, characterized in that, Obtaining the working condition of the excavator includes: Obtaining the opening of the boom handle and the opening of the stick handle; When the opening of the boom handle and the opening of the stick handle are both greater than or equal to a first threshold, it is determined that the working condition of the excavator is a flat ground working condition; When one of the opening of the boom handle and the opening of the stick handle is 0 and the other is greater than or equal to a second threshold, it is determined that the working condition of the excavator is a single-action working condition.

4. The control method of the excavator according to claim 3, characterized in that, Determining the calculation method of the motor speed demand corresponding to the excavator according to the working condition includes: When the working condition is a single-action working condition, obtaining the opening information of the single-action handle and the displacement of the single-action hydraulic pump; Determining the flow demand of the hydraulic pump corresponding to the single action according to the opening information; Determining the rotational speed demand of the motor corresponding to the single action according to the flow demand of the hydraulic pump corresponding to the single action and the displacement of the hydraulic pump.

5. The control method of the excavator according to claim 3, characterized in that, Determining the calculation method of the motor speed demand corresponding to the excavator according to the working condition includes: When the working condition is a flat ground working condition, obtaining the opening of the boom handle and the opening of the stick handle; Respectively determining the rising / falling flow demand of the boom pump and the retracting / extending flow demand of the stick pump according to the opening of the boom handle and the opening of the stick handle; Determining the rotational speed demand of the boom motor according to the rising / falling flow demand of the boom pump and the displacement of the boom pump; Determining the rotational speed demand of the stick motor according to the retracting / extending flow demand of the stick pump and the displacement of the stick pump.

6. The control method of the excavator according to claim 5, wherein After obtaining the opening of the boom handle and the opening of the stick handle, it further includes: Determine a first limit coefficient according to the opening degree of the boom handle; Determine the lifting flow demand of the boom according to the first limit coefficient and the maximum lifting flow demand of the boom; wherein, the maximum lifting flow demand of the boom pump decreases as the time of the excavator in the flat ground working condition increases.

7. The control method of the excavator according to claim 5, wherein The motor speed demand of the boom and the motor speed demand of the stick are calculated by formula (1): Wherein, n is the motor speed demand of the boom or the motor speed demand of the stick, Q is the lifting flow demand or the recovery flow demand, and q is the displacement of the boom hydraulic pump or the displacement of the stick hydraulic pump.

8. The control method of the excavator according to claim 5, characterized in that, The stick further includes a first chamber and a second chamber, and the pressure receiving area of the first chamber is smaller than the pressure receiving area of the second chamber; after the working condition is the flat ground working condition, it further includes: Obtain the pressure of the first chamber and the pressure of the second chamber of the stick; Determine the pressure difference of the stick according to the pressure of the first chamber and the pressure of the second chamber; Determine the lifting rate of the boom according to the pressure difference.

9. A control device for an excavator, characterized in that, The excavator includes a first control circuit and a second control circuit; the first control circuit at least includes: a boom motor, a boom pump, a first hydraulic valve and a boom; the second control circuit at least includes: a stick motor, a stick pump, a second hydraulic valve and a stick; the output end of the boom motor is connected to the boom pump, and the boom motor drives the boom pump to control the valve opening degree of the first hydraulic valve to realize the rising or falling of the boom; the output end of the stick motor is connected to the stick pump, and the stick motor drives the stick pump to control the valve opening degree of the second hydraulic valve to realize the retraction or extension of the stick; wherein, the boom pump and the stick pump are both hydraulic pumps; the control device includes: An opening degree acquisition module, configured to acquire the opening degree information of the handle; A flow demand determination module, configured to determine the flow demand of the boom pump and / or the flow demand of the stick pump according to the opening degree information; A speed demand determination module, configured to determine the motor speed demand of the boom motor and / or the motor speed demand of the stick motor according to the flow demand of the boom pump and / or the flow demand of the stick pump; An execution module, configured to send the motor speed demand of the boom motor and / or the motor speed demand of the stick motor to the motor controller of the excavator to control the excavator.

10. An excavator, characterized in that, The control device of the excavator according to claim 9 is included.

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