Electric excavator, control method and device of electric drive rotation system of electric excavator and medium

Abstract

The invention discloses an electric excavator, a control method and device of an electric drive rotation system and a medium, and relates to the technical field of electric excavator rotation control. The method comprises the steps that dynamics modeling is conducted on the excavator electric drive rotation system, and a dynamics model is obtained; and based on the dynamic model, selecting a system state variable, and establishing a non-singular fast terminal sliding mode speed controller by taking the minimum whole machine rotation speed tracking error and the small torque impact as a control target. The excavator structure is simplified, a space coordinate system and a D-H method coordinate system are established, then a mathematical model of the gravity center of the working device and the rotational inertia changing along with the posture is established, and a total rotational inertia mathematical model of the excavator is obtained. Aiming at disturbance caused by load change and time-varying inertia in the rotation working condition of the excavator, a Luenberger observer is built, an observed load value is fed forward to a rotation speed controller, and updated control data is obtained. The problems that the rotation speed is unstable, the torque pulsation is large, and the controllability is poor can be solved.

Description

Technical Field

[0001] This invention relates to the field of electric excavator slewing control technology, and more specifically, to a control method, device, and medium for an electric excavator and its electric drive slewing system. Background Technology

[0002] Traditional hydraulically driven excavators suffer from significant energy efficiency and maneuverability issues during slewing operations. When using a hydraulic motor to drive the slewing system, the energy transmission path is relatively long, and the overall machine energy efficiency is typically only 15%-30%. Especially during micro-motion operations, a large amount of hydraulic oil needs to flow through the throttle valve, generating heat and causing energy to be dissipated as heat, resulting in serious energy waste. In addition, hydraulic drive systems struggle to achieve smooth and precise start-stop and micro-operations, affecting operational responsiveness and accuracy, and limiting further improvements in overall machine performance.

[0003] In contrast, the electric drive slewing system used in electric excavators has advantages such as a short energy transfer path, high energy efficiency, and zero carbon emissions. It can also efficiently recover braking energy and store it in batteries or supercapacitors, significantly improving energy utilization efficiency. The electric drive system also supports smooth speed regulation and precise micro-operation, which is conducive to the intelligent and digital development of the entire machine.

[0004] However, in actual slewing operations, due to the strong periodicity of the working conditions and the compound actions of multiple actuators, the system still faces frequent load disturbances and time-varying inertia problems, which directly affect the stability of the slewing speed and the quality of operation.

[0005] The aforementioned load disturbances and time-varying inertia issues not only reduce the dynamic response performance of the electric drive slewing system but also lead to increased torque pulsation and system energy consumption, thereby affecting the overall machine's economy and reliability. Therefore, a highly stable control method capable of effectively suppressing external disturbances and inertia variations is urgently needed to improve the overall performance of electric excavators in complex operating environments. Summary of the Invention The present invention provides a control method, device and medium for an electric excavator and its electric drive slewing system to improve at least one of the above-mentioned technical problems.

[0006] In a first aspect, the present invention provides a control method for the electric drive slewing system of an electric excavator, which includes the following steps.

[0007] Dynamic modeling was performed on the electric drive slewing system of the excavator to obtain the dynamic model.

[0008] Based on the dynamic model, the system state variables are selected, and a non-singular fast terminal sliding mode speed controller is built with the goal of minimizing the tracking error of the overall machine rotation speed and minimizing the torque impact.

[0009] A simplified excavator structure is established using a spatial coordinate system and a DH method coordinate system. Then, a mathematical model of the center of gravity of the working device and the moment of inertia that varies with the orientation is constructed to obtain a mathematical model of the total moment of inertia of the excavator.

[0010] To address the disturbances caused by load changes and time-varying inertia during the excavator's swing operation, a Luneburger observer was built, and the observed load values ​​were fed forward to the swing speed controller to obtain updated control data.

[0011] In an optional implementation, the dynamic model is: In the formula. This represents the rotational inertia of the entire machine. It is a differential. This refers to the overall rotational angular velocity of the machine. For time. This is the driving torque for the rotation of the entire machine. This is the rotational load torque of the entire machine. is the viscosity coefficient.

[0012] In an optional implementation, the system state variable is: In the formula, This refers to the tracking error of the overall machine's rotational angular velocity. This is the given value for the overall rotational angular velocity. This is the actual value of the overall machine's rotational angular velocity, which can be considered a constant. This represents the rate of change of the tracking error of the overall machine's rotational angular velocity. for The first derivative. for The first derivative.

[0013] In an optional implementation, the state-space equations of the electric-driven rotary system are obtained based on the dynamic model and the system state variables: In the formula. This represents the rotational inertia of the entire machine. This is the rotational load torque of the entire machine. is the viscosity coefficient. This is the driving torque for the rotation of the entire machine. for The first derivative. for The second derivative. for The first derivative. for The first derivative.

[0014] Obtaining the non-singular fast terminal sliding surface: In the formula, It is a sliding surface. This is the first control gain coefficient. This is the second control gain coefficient. This is the third control gain coefficient. It is the first positive odd number. It is the second positive odd number. , and , .

[0015] Differentiate the sliding surface with respect to the nonsingular fast terminal to obtain the first derivative of the sliding surface: .

[0016] Based on the first derivative of the sliding surface, obtain the exponential convergence rate: In the formula, This represents the exponential rate of convergence. The coefficient of the exponential approach term. It is the hyperbolic tangent function. This is the adjustment coefficient for the saturation function. To switch the gain. Among them, , and All are constants greater than 0.

[0017] By simultaneously solving the state-space equations, the first derivative of the sliding surface, and the exponential reaching rate, a non-singular fast terminal sliding mode velocity controller can be obtained. In the formula, This is the output of the controller. It is a differential. For time.

[0018] In an alternative implementation, a Lyapunov function is constructed based on Lyapunov stability theory: .

[0019] Differentiating the Lyapunov function yields its first derivative: .

[0020] By combining the first derivative of the sliding surface, the nonsingular fast terminal sliding mode control law, and the first derivative of the Lyapunov function, the system stability condition model is obtained: In the formula, . Let be the natural base. .

[0021] but In the formula For positive definiteness, The value is negative definite, which satisfies the system stability condition and can guarantee the stable operation of the system.

[0022] In an optional implementation, a simplified excavator structure is established using a spatial coordinate system and a DH method coordinate system. Then, a mathematical model of the working device's center of gravity and its moment of inertia as its orientation changes is constructed to obtain the excavator's total moment of inertia mathematical model. Specifically, this includes: Simplify the excavator structure, using the swing center of gravity as the coordinate origin. Establish a spatial coordinate system .

[0023] Establish the DH coordinate system with the hinge points of the boom and turntable, the stick and boom, and the bucket and stick as the origins in sequence.

[0024] By multiplying the spatial coordinate transformation matrices, the coordinates of the center of gravity of each working component are obtained, and a mathematical model of the center of gravity of the working device and the moment of inertia that changes with the posture is constructed, thus obtaining the mathematical model of the total moment of inertia of the excavator.

[0025] In an optional implementation, the hinge point between the boom and the turntable is set as... Point, the hinge point between the stick and the boom is Point, the hinge point between the bucket and the stick is Point, the tip of the bucket teeth is point.

[0026] The spatial coordinate transformation matrix is ​​represented as: .

[0027] .

[0028] .

[0029] In the formula, , , These represent rotations about the x, y, and z axes, respectively. Spatial coordinate transformation matrix of degrees.

[0030] set up The local coordinates of the point are .

[0031] The coordinates of the point in the spatial coordinate system are: .

[0032] In spatial coordinate system The coordinate expression of a point is: .

[0033] In the formula, This represents the slewing angle of the boom. Represented as and The length between two points.

[0034] In spatial coordinate system The coordinate expression of a point is: .

[0035] In the formula, This refers to the rotation angle of the boom. Represented as and The length between two points.

[0036] In spatial coordinate system The coordinate expression of a point is: .

[0037] In the formula, This refers to the rotation angle of the bucket. Represented as and The length between two points.

[0038] The coordinates of the centroid are obtained based on the trigonometric relationship between the centroid and the hinge point. Specifically, the coordinates of the centroid are... In the coordinate expression of a point Replace with ,Will In the coordinate expression of a point Replace with ,Will In the coordinate expression of a point Replace with The coordinates of the center of gravity of the boom, stick, and bucket are obtained respectively.

[0039] .

[0040] .

[0041] .

[0042] In the formula, Here are the coordinates of the boom's center of gravity. These are the coordinates of the pole's center of gravity. These are the coordinates of the bucket's center of gravity. for Point to the center of gravity of the boom The vector length. This is the angle of the boom's center of gravity offset. for Point to the center of gravity of the pole The vector length. The angle of the pole's center of gravity offset. for Point to the center of gravity of the bucket The vector length. This is the angle of the bucket's center of gravity offset.

[0043] The mathematical model for the total moment of inertia is: .

[0044] in, This represents the moment of inertia of the entire machine. This indicates that the moment of inertia of the turntable is a fixed value. This represents the moment of inertia of the boom. This represents the moment of inertia of the boom. This represents the moment of inertia of the bucket. This indicates the boom mass. Indicates the mass of the boom. Indicates the mass of the bucket.

[0045] In an alternative implementation, the state-space equation of the Lundberg observer is: In the formula, To find the first derivative with respect to the observed values ​​of the state variable. Let be the state matrix of the system. These are the observed values ​​of the state variables. This is the system's input matrix. Input for the system. This is the error feedback matrix. This is the output. These are the output observations. This is the output matrix. This is a direct matrix.

[0046] In an optional implementation, the moment of inertia of the entire machine is expressed as... Substituting this into the Luneburg observer and setting the characteristic polynomial output of the Luneburg observer to 0 yields the convergent model: .

[0047] In the formula, These are the eigenvalues ​​of the matrix. It is an identity matrix. This is the gain matrix of the Luneburg observer. This is the first gain for the Romberg observer. This is the second gain for the Romberg observer. This is the first eigenvalue of the Romberg observer. This is the second eigenvalue of the Romberg observer. . . . The gain of the Luneburg observer is: .

[0048] The load value observed by the Lunberg observer Feedforward to the non-singular fast terminal sliding mode speed controller to obtain updated control data.

[0049] .

[0050] In the formula, For the updated control data, This represents the load torque observation value output by the Luneburger observer.

[0051] Secondly, the present invention provides a control device for the electric drive slewing system of an electric excavator, which includes the following modules.

[0052] The model building module is used to perform dynamic modeling on the electric drive slewing system of an excavator and obtain the dynamic model.

[0053] The controller module is used to select system state variables based on the dynamic model and to build a non-singular fast terminal sliding mode speed controller with the control objective of minimizing the tracking error of the overall machine rotation speed and minimizing torque impact.

[0054] The moment of inertia module is used to simplify the excavator structure by establishing a spatial coordinate system and a DH method coordinate system. Then, it constructs a mathematical model of the center of gravity of the working device and the moment of inertia that changes with the posture, and obtains the mathematical model of the total moment of inertia of the excavator.

[0055] The update module is used to build a Luneburger observer to address disturbances caused by load changes and time-varying inertia during the excavator's swing operation, and feeds the observed load values ​​forward to the swing speed controller to obtain updated control data.

[0056] Thirdly, the present invention provides an electric excavator, which includes a processor, a memory, and a computer program stored in the memory. The computer program can be executed by the processor to implement a control method for the electric drive slewing system of an electric excavator as described in any paragraph of the first aspect.

[0057] Fourthly, the present invention provides a computer-readable storage medium comprising a stored computer program, wherein, when the computer program is executed, it controls the device containing the computer-readable storage medium to perform a control method for an electric drive slewing system of an electric excavator as described in any paragraph of the first aspect.

[0058] By adopting the above technical solution, the present invention can achieve the following technical effects: This invention, through the design of a sliding mode speed controller with disturbance compensation, can solve the problems of unstable slewing speed, large torque pulsation, and poor maneuverability caused by load disturbances and time-varying inertia in electric-driven excavators. It also improves the energy efficiency of the electric drive system.

[0059] This invention models the electric drive slewing system of an excavator and builds a non-singular fast terminal sliding mode speed controller based on the system's state-space equations. Simultaneously, it obtains a mathematical model of the machine's rotational inertia using the DH method and spatial coordinate transformation matrix. This mathematical model is then combined with a Luneburger observer to improve the accuracy of the observed values, which are then fed forward to the sliding mode speed controller. This process can resist the influence of load disturbances and time-varying inertia during slewing, resulting in stable slewing speed without overshoot. This improves maneuverability while reducing energy consumption. Attached Figure Description

[0060] To more clearly illustrate the technical solution of the present invention, the accompanying drawings used in the specific embodiments of the present invention will be briefly introduced below. It should be understood that the following drawings only show some specific embodiments of the present invention and should not be regarded as a limitation on the scope. For those skilled in the art, other related drawings can be obtained from these drawings without creative effort.

[0061] Figure 1 This is a flowchart illustrating the control method of the electric drive slewing system of an electric excavator.

[0062] Figure 2 It is a simplified model of the whole machine in the DH coordinate system.

[0063] Figure 3 This is a simulation comparison of the overall vehicle rotation speed of the electric drive slewing system of an electric excavator under traditional excavation slewing conditions.

[0064] Figure 4 The results are simulations of the tracking error of the electric drive slewing system of an electric excavator under traditional excavation slewing conditions.

[0065] Figure 5 This is a simulation result of the effective energy output of the rotary motor of an electric excavator's electric drive rotary system under traditional excavation conditions. Detailed Implementation

[0066] The technical solutions of the present invention will now be clearly and completely described with reference to the accompanying drawings in the embodiments of the present invention.

[0067] Example 1, please refer to Figures 1 to 5The first embodiment of the present invention provides a control method for the electric drive slewing system of an electric excavator, which can be executed by a control device for the electric drive slewing system of the electric excavator (hereinafter referred to as: control device). In particular, it is executed by one or more processors in the control device to implement steps S1 to S4.

[0068] S1. Perform dynamic modeling on the electric drive slewing system of the excavator to obtain the dynamic model.

[0069] Preferably, the dynamic model of the electric drive slewing system of the electric excavator is as follows: .

[0070] In the formula. This represents the rotational inertia of the entire machine. It is a differential. This refers to the overall rotational angular velocity of the machine. For time. This is the driving torque for the rotation of the entire machine. This is the rotational load torque of the entire machine. is the viscosity coefficient.

[0071] S2. Based on the dynamic model, select the system state variables, and take the minimum tracking error of the whole machine rotation speed and the small torque impact as the control objective to build a non-singular fast terminal sliding mode speed controller.

[0072] Based on the above embodiments, in an optional embodiment of the present invention, step S2 includes steps S21 to S26.

[0073] S21. Based on the dynamic model, select the system state variables. The system state variables are: .

[0074] In the formula, This refers to the tracking error of the overall machine's rotational angular velocity. This is the given value for the overall rotational angular velocity. This is the actual value of the overall machine's rotational angular velocity, which can be considered a constant. This represents the rate of change of the tracking error of the overall machine's rotational angular velocity. for The first derivative. for The first derivative.

[0075] S22. Based on the dynamic model and the system state variables, obtain the state-space equation of the electric drive rotary system: .

[0076] In the formula. This represents the rotational inertia of the entire machine. This is the rotational load torque of the entire machine. is the viscosity coefficient. This is the driving torque for the rotation of the entire machine. for The first derivative. for The second derivative. for The first derivative. for The first derivative.

[0077] S23. Obtain the non-singular fast terminal sliding surface: .

[0078] In the formula, It is a non-singular fast terminal sliding surface. This is the first control gain coefficient. This is the second control gain coefficient. This is the third control gain coefficient. It is the first positive odd number. It is the second positive odd number. Where 1 < <2, and , .

[0079] S24. Take the derivative with respect to the non-singular fast terminal sliding surface to obtain the first derivative of the sliding surface: .

[0080] S25. Obtain the exponential convergence rate based on the first derivative of the sliding surface: .

[0081] In the formula, This represents the exponential rate of convergence. The coefficient of the exponential approach term. It is the hyperbolic tangent function. This is the adjustment coefficient for the saturation function. To switch the gain. Among them, , and All are constants greater than 0.

[0082] S26. By simultaneously solving the state-space equations, the first derivative of the sliding surface, and the exponential reaching rate, obtain the non-singular fast terminal sliding mode velocity controller: .

[0083] In the formula, This is the output of the controller. It is a differential. For time.

[0084] Based on the above embodiments, in an optional embodiment of the present invention, step S2 further includes steps S27 to S29.

[0085] S27. Construct the Lyapunov function based on Lyapunov stability theory: .

[0086] S28. Take the derivative of the Lyapunov function to obtain its first derivative: .

[0087] S29. By combining the first derivative of the sliding surface, the non-singular fast terminal sliding mode control law, and the first derivative of the Lyapunov function, obtain the system stability condition model: .

[0088] In the formula, . It is the natural base. , , ,and and If it is a positive odd number, then .

[0089] but In the formula For positive definiteness, If the value is negative, the system stability condition is met, which can guarantee the stable operation of the system.

[0090] S3. Simplify the excavator structure, establish a spatial coordinate system and a DH method coordinate system, and then construct a mathematical model of the center of gravity of the working device and the moment of inertia that changes with the posture, and obtain the mathematical model of the total moment of inertia of the excavator.

[0091] Based on the above embodiments, in an optional embodiment of the present invention, such as Figure 2 The figure shows a simplified model of the entire machine in the DH coordinate system. Preferably, step S3 specifically includes: S31. Simplify the excavator structure, using the slewing center of gravity as the coordinate origin. Establish a spatial coordinate system .

[0092] S32. Establish the DH coordinate system with the hinge points of the boom and turntable, the boom and stick, and the bucket and stick as the origins in sequence.

[0093] S33. By multiplying the spatial coordinate transformation matrices, the coordinates of the center of gravity of each working component are obtained, and a mathematical model of the center of gravity of the working device and the moment of inertia that changes with the posture is constructed to obtain the mathematical model of the total moment of inertia of the excavator.

[0094] Set the hinge point between the boom and the turntable as Point, the hinge point between the stick and the boom is Point, the hinge point between the bucket and the stick is Point, the tip of the bucket teeth is point.

[0095] The spatial coordinate transformation matrix is: .

[0096] .

[0097] .

[0098] In the formula, , , These represent rotations about the x, y, and z axes, respectively. Spatial coordinate transformation matrix of degrees.

[0099] Setting the hinge point between the boom and the turntable The local coordinates are .

[0100] In spatial coordinate system The coordinate expression of a point is: .

[0101] In spatial coordinate system The coordinate expression of a point is: .

[0102] In the formula, This represents the slewing angle of the boom. Represented as and The length between two points.

[0103] In spatial coordinate system The coordinate expression of a point is: .

[0104] In the formula, This refers to the rotation angle of the boom. Represented as and The length between two points.

[0105] In spatial coordinate system The coordinate expression of a point is: .

[0106] In the formula, This refers to the rotation angle of the bucket. Represented as and The length between two points.

[0107] The coordinates of the centroid are obtained based on the trigonometric relationship between the centroid and the hinge point. Specifically, the coordinates of the centroid are... In the coordinate expression of a point Replace with ,Will In the coordinate expression of a point Replace with ,Will In the coordinate expression of a point Replace with The coordinates of the center of gravity of the boom, stick, and bucket are obtained respectively.

[0108] .

[0109] .

[0110] .

[0111] In the formula, Here are the coordinates of the boom's center of gravity. These are the coordinates of the pole's center of gravity. These are the coordinates of the bucket's center of gravity. for Point to the center of gravity of the boom The vector length. This is the angle of the boom's center of gravity offset. for Point to the center of gravity of the pole The vector length. The angle of the pole's center of gravity offset. for Point to the center of gravity of the bucket The vector length. This is the angle of the bucket's center of gravity offset.

[0112] The mathematical model for the total moment of inertia is: .

[0113] In the formula, This represents the rotational inertia of the entire machine. The moment of inertia of the turntable is a fixed value. Let be the moment of inertia of the boom. Let be the moment of inertia of the boom. Let be the moment of inertia of the bucket. The mass of the boom. This refers to the mass of the boom. For bucket quality. for Point to the center of gravity of the boom The vector length. for Point to the center of gravity of the pole The vector length. for Point to the center of gravity of the bucket The vector length.

[0114] S4. To address the disturbances caused by load changes and time-varying inertia during the excavator's slewing operation, a Luneburger observer is built, and the observed load values ​​are fed forward to the slewing speed controller to obtain updated control data.

[0115] Preferably, the state-space equation of the Luneburger observer is: .

[0116] In the formula, To find the first derivative with respect to the observed values ​​of the state variable. Let be the state matrix of the system. These are the observed values ​​of the state variables. This is the system's input matrix. Input for the system. This is the error feedback matrix. This is the output. These are the output observations. This is the output matrix. This is a direct matrix.

[0117] The moment of inertia of the entire machine is expressed as... Substituting this into the Luneburg observer and setting the characteristic polynomial output of the Luneburg observer to 0 yields the convergent model: .

[0118] In the formula, These are the eigenvalues ​​of the matrix. It is an identity matrix. This is the gain matrix of the Luneburg observer. This is the first gain for the Romberg observer. This is the second gain for the Romberg observer. This is the first eigenvalue of the Romberg observer. This is the second eigenvalue of the Romberg observer. . . .

[0119] The gain of the Luneburg observer is: .

[0120] The load values ​​observed by the Luneburger observer are fed forward to the non-singular fast terminal sliding mode speed controller to obtain updated control data (i.e., output).

[0121] .

[0122] In the formula, For the updated control data, This represents the load torque observation value output by the Luneburger observer.

[0123] In a specific embodiment provided by the present invention, the main parameters of the slewing system are shown in Table 1, and the main parameters of the controller are shown in Table 2.

[0124] Table 1 Main parameters of the slewing system

[0125] Table 2 Main Parameters of the Controller

[0126] The simulation results are as follows: Figure 3 and Figure 4 As shown, the non-singular fast terminal sliding mode speed controller (NFTSMC+DOB controller) with disturbance compensation, built based on the control method of the electric drive slewing system of the electric excavator of this invention, can stably follow the target speed curve under digging slewing conditions. Its response speed is approximately 70ms faster than the PID controller. The maximum speed tracking error of the PID controller is 0.6 rpm, and the average tracking error is 0.31 rpm, while the maximum speed tracking error of the NFTSMC+DOB controller is 0.51 rpm, and the average tracking error is 0.23 rpm. Figure 3 In this context, PID represents a PID controller, and NFTSMC+DOB represents an NFTSMC+DOB controller.

[0127] The NFTSMC+DOB controller effectively reduces the impact of load disturbances and rotational inertia on the rotation speed during excavation rotation, thus improving maneuverability. For example... Figure 5 As shown, under a single cycle of excavation rotation, the rotary motor ultimately consumes 17.8 kJ of energy, of which the total energy consumption is 98.4 kJ and the total energy feedback is 80.6 kJ, with an energy saving rate of 63.6%.

[0128] This invention, through the design of a sliding mode speed controller with disturbance compensation, can solve the problems of unstable slewing speed, large torque pulsation, and poor maneuverability caused by load disturbances and time-varying inertia in electric-driven excavators. It also improves the energy efficiency of the electric drive system.

[0129] This invention models the electric drive slewing system of an excavator and builds a non-singular fast terminal sliding mode speed controller based on the system's state-space equations. Simultaneously, it obtains a mathematical model of the machine's rotational inertia using the DH method and spatial coordinate transformation matrix. This mathematical model is then combined with a Luneburger observer to improve the accuracy of the observed values, which are then fed forward to the sliding mode speed controller. This process can resist the influence of load disturbances and time-varying inertia during slewing, resulting in stable slewing speed without overshoot. This improves maneuverability while reducing energy consumption.

[0130] Example 2: The present invention provides a control device for the electric drive slewing system of an electric excavator, which includes the following modules.

[0131] The model building module is used to perform dynamic modeling on the electric drive slewing system of an excavator and obtain the dynamic model.

[0132] The controller module is used to select system state variables based on the dynamic model and to build a non-singular fast terminal sliding mode speed controller with the control objective of minimizing the tracking error of the overall machine rotation speed and minimizing torque impact.

[0133] The moment of inertia module is used to simplify the excavator structure by establishing a spatial coordinate system and a DH method coordinate system. Then, it constructs a mathematical model of the center of gravity of the working device and the moment of inertia that changes with the posture, and obtains the mathematical model of the total moment of inertia of the excavator.

[0134] The update module is used to build a Luneburger observer to address disturbances caused by load changes and time-varying inertia during the excavator's swing operation, and feeds the observed load values ​​forward to the swing speed controller to obtain updated control data.

[0135] Example 3: This invention provides an electric excavator, which includes a processor, a memory, and a computer program stored in the memory. The computer program can be executed by the processor to implement a control method for the electric drive slewing system of an electric excavator as described in any paragraph of Example 1.

[0136] Example 4: The present invention provides a computer-readable storage medium, the computer-readable storage medium including a stored computer program, wherein, when the computer program is executed, it controls the device where the computer-readable storage medium is located to execute a control method for the electric drive slewing system of an electric excavator as described in any paragraph of Example 1.

[0137] It is understood that the control device may be the control device on an electric excavator, or a remote server or other electronic device with computing power.

[0138] Obviously, the embodiments described above are only some embodiments of the present invention, and not all embodiments. All other embodiments obtained by those skilled in the art based on the embodiments of the present invention without inventive effort are within the scope of protection of the present invention.

[0139] In the several embodiments provided in this invention, it should be understood that the disclosed apparatus and methods can also be implemented in other ways. The apparatus and method embodiments described above are merely illustrative. For example, the flowcharts and block diagrams in the accompanying drawings illustrate the architecture, functionality, and operation of possible implementations of apparatus, methods, and computer program products according to various embodiments of the present invention. In this regard, each block in a flowchart or block diagram may represent a module, segment, or portion of code containing one or more executable instructions for implementing a specified logical function. It should also be noted that in some alternative implementations, the functions marked in the blocks may occur in a different order than those marked in the drawings. For example, two consecutive blocks may actually be executed substantially in parallel, and they may sometimes be executed in reverse order, depending on the functions involved. It should also be noted that each block in a block diagram and / or flowchart, and combinations of blocks in block diagrams and / or flowcharts, can be implemented using a dedicated hardware-based system that performs the specified function or action, or using a combination of dedicated hardware and computer instructions.

[0140] In addition, the functional modules in the various embodiments of the present invention can be integrated together to form an independent part, or each module can exist independently, or two or more modules can be integrated to form an independent part.

[0141] If the aforementioned functions are implemented as software functional modules and sold or used as independent products, they can be stored in a computer-readable storage medium. Based on this understanding, the technical solution of the present invention, or the part that contributes to the prior art, or a part of the technical solution, can be embodied in the form of a software product. This computer software product is stored in a storage medium and includes several instructions to cause a computer device (which may be a personal computer, electronic device, or network device, etc.) to execute all or part of the steps of the methods described in the various embodiments of the present invention. The aforementioned storage medium includes various media capable of storing program code, such as USB flash drives, portable hard drives, read-only memory, random access memory, magnetic disks, or optical disks. It should be noted that, in this document, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a process, method, article, or apparatus. Without further limitations, an element defined by the phrase "comprising one..." does not exclude the presence of other identical elements in the process, method, article, or apparatus that includes said element.

[0142] The terminology used in the embodiments of this invention is for the purpose of describing particular embodiments only and is not intended to be limiting of the invention. The singular forms “a,” “the,” and “the” used in the embodiments of this invention are also intended to include the plural forms unless the context clearly indicates otherwise.

[0143] It should be understood that the term "and / or" used in this article is merely a description of the relationship between related objects, indicating that three relationships can exist. For example, A and / or B can represent: A existing alone, A and B existing simultaneously, and B existing alone. Additionally, the character " / " in this article generally indicates that the preceding and following related objects have an "or" relationship.

[0144] Depending on the context, the word "if" as used here can be interpreted as "when," "when," "in response to determination," or "in response to detection." Similarly, depending on the context, the phrase "if determination" or "if detection (of the stated condition or event)" can be interpreted as "when determination," "in response to determination," "when detection (of the stated condition or event)," or "in response to detection (of the stated condition or event)."

[0145] The terms "first" and "second" used in the embodiments are merely to distinguish similar objects and do not represent a specific ordering of objects. It is understood that "first" and "second" can be interchanged in a specific order or sequence where permitted. It should be understood that the objects distinguished by "first" and "second" can be interchanged where appropriate so that the embodiments described herein can be implemented in an order other than those illustrated or described herein.

[0146] The above description is merely a preferred embodiment of the present invention and is not intended to limit the invention. Various modifications and variations can be made to the present invention by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the scope of protection of the present invention.

Claims

1. A control method for the electric drive slewing system of an electric excavator, characterized in that, Include: Dynamic modeling of the excavator's electric drive slewing system was performed to obtain the dynamic model. Based on the dynamic model, the system state variables are selected, and the control objectives are to minimize the tracking error of the overall machine rotation speed and minimize the torque impact. A non-singular fast terminal sliding mode speed controller is built. Simplify the excavator structure to establish a spatial coordinate system and a DH method coordinate system, then construct a mathematical model of the center of gravity of the working device and the moment of inertia that changes with the posture, and obtain a mathematical model of the total moment of inertia of the excavator. To address the disturbances caused by load changes and time-varying inertia during the excavator's swing operation, a Luneburger observer was built, and the observed load values ​​were fed forward to the swing speed controller to obtain updated control data.

2. The control method for the electric drive slewing system of an electric excavator according to claim 1, characterized in that, The dynamic model is as follows: In the formula; This represents the rotational inertia of the entire machine. It is a differential; This refers to the overall rotational angular velocity of the machine. For time; This is the driving torque for the rotation of the entire machine; This is the rotational load torque of the entire machine; is the viscosity coefficient.

3. The control method for the electric drive slewing system of an electric excavator according to claim 1, characterized in that, The system state variables are: In the formula, This refers to the tracking error of the overall machine's rotational angular velocity. The given value is the rotational angular velocity of the entire machine; This is the actual value of the overall machine's rotational angular velocity, which can be considered a constant. This represents the rate of change of the tracking error of the overall machine's rotational angular velocity. for The first derivative; for The first derivative; Based on the dynamic model and the system state variables, the state-space equations of the electric drive rotary system are obtained as follows: In the formula; This represents the rotational inertia of the entire machine. This is the rotational load torque of the entire machine; The viscosity coefficient; This is the driving torque for the rotation of the entire machine; for The first derivative; for The second derivative; for The first derivative; for The first derivative; Obtaining the non-singular fast terminal sliding surface: In the formula, It is a sliding surface; The first control gain coefficient; This is the second control gain coefficient; This is the third control gain coefficient; It is the first positive odd number; It is the second positive odd number; among them, , and , ; Differentiate the sliding surface with respect to the nonsingular fast terminal to obtain the first derivative of the sliding surface: ; Based on the first derivative of the sliding surface, obtain the exponential convergence rate: In the formula, For exponential convergence rate; The coefficient of the exponential approach term; It is the hyperbolic tangent function; This is the adjustment coefficient for the saturation function; To switch the gain; where, , and All are constants greater than 0; By simultaneously solving the state-space equations, the first derivative of the sliding surface, and the exponential reaching rate, a non-singular fast terminal sliding mode velocity controller can be obtained. In the formula, This is the output of the controller; It is a differential; For time.

4. The control method for the electric drive slewing system of an electric excavator according to claim 3, characterized in that, Based on Lyapunov stability theory, construct the Lyapunov function: ; Differentiating the Lyapunov function yields its first derivative: ; By combining the first derivative of the sliding surface, the nonsingular fast terminal sliding mode control law, and the first derivative of the Lyapunov function, the system stability condition model is obtained: In the formula, ; If the base is natural, then... ; but In the formula For positive definiteness, The value is negative definite, which satisfies the system stability condition and can guarantee the stable operation of the system.

5. The control method for the electric drive slewing system of an electric excavator according to claim 1, characterized in that, A simplified excavator structure is established using a spatial coordinate system and a DH (Hallucination and Deutsche Hauschka) coordinate system. Then, a mathematical model of the working device's center of gravity and its moment of inertia as its orientation changes is constructed to obtain the excavator's total moment of inertia mathematical model. This specifically includes: Simplify the excavator structure, using the swing center of gravity as the coordinate origin. Establish a spatial coordinate system ; Establish the DH coordinate system with the hinge points of the boom and turntable, the stick and boom, and the bucket and stick as the origins in sequence; By multiplying the spatial coordinate transformation matrices, the coordinates of the center of gravity of each working component are obtained, and a mathematical model of the center of gravity of the working device and the moment of inertia that changes with the posture is constructed, thus obtaining the mathematical model of the total moment of inertia of the excavator.

6. The control method for the electric drive slewing system of an electric excavator according to claim 5, characterized in that, Set the hinge point between the boom and the turntable as Point, the hinge point between the stick and the boom is Point, the hinge point between the bucket and the stick is Point, the tip of the bucket teeth is point; The spatial coordinate transformation matrix is ​​represented as: ； ； ； In the formula, , , These represent rotations about the x, y, and z axes, respectively. Spatial coordinate transformation matrix of degree; set up The local coordinates of the point are ; The coordinates of the point in the spatial coordinate system are: ； In spatial coordinate system The coordinate expression of a point is: ； In the formula, This is the slewing angle of the boom; Represented as and The length between two points; In spatial coordinate system The coordinate expression of a point is: ； In the formula, This refers to the rotation angle of the boom; Represented as and The length between two points; In spatial coordinate system The coordinate expression of a point is: ； In the formula, This refers to the rotation angle of the bucket; Represented as and The length between two points; The coordinates of the centroid are obtained based on the trigonometric function relationship between the centroid and the hinge point; where, In the coordinate expression of a point Replace with ,Will In the coordinate expression of a point Replace with ,Will In the coordinate expression of a point Replace with The coordinates of the center of gravity of the boom, stick, and bucket are obtained respectively. ； ； ； In the formula, The coordinates of the boom's center of gravity; The coordinates of the pole's center of gravity; The coordinates of the bucket's center of gravity; for Point to the center of gravity of the boom The vector length; The angle of the boom's center of gravity offset; for Point to the center of gravity of the pole The vector length; The angle of offset of the pole's center of gravity; for Point to the center of gravity of the bucket The vector length; This is the angle of the bucket's center of gravity offset; The mathematical model for the total moment of inertia is: ； in, Indicates the moment of inertia of the entire machine; This indicates that the turntable's moment of inertia is a fixed value; Indicates the moment of inertia of the boom; Indicates the moment of inertia of the boom; Indicates the moment of inertia of the bucket; Indicates the boom mass; Indicates the mass of the boom; Indicates the mass of the bucket.

7. The control method for the electric drive slewing system of an electric excavator according to claim 1, characterized in that, The state-space equation of the Luneburg observer is: In the formula, To obtain the first derivative with respect to the observed values ​​of the state variable; The state matrix of the system; These are the observed values ​​of the state variables; The input matrix of the system; Input for the system; This is the error feedback matrix; For output; These are the output observations; This is the output matrix; For direct access matrices; The moment of inertia of the entire machine is expressed as... Substituting this into the Luneburg observer and setting the characteristic polynomial output of the Luneburg observer to 0 yields the convergent model: ； In the formula, These are the eigenvalues ​​of the matrix; It is the identity matrix; Here is the gain matrix of the Luneburg observer; The first gain of the Romberg observer; This is the second gain for the Lundberg observer; This is the first eigenvalue of the Lundberg observer; This is the second eigenvalue of the Lundberg observer; ; ; ; The gain of the Luneburg observer is: ； The load value observed by the Lunberg observer Feedforward to the non-singular fast terminal sliding mode speed controller to obtain updated control data; ； In the formula, For the updated control data, This represents the load torque observation value output by the Luneburger observer.

8. A control device for the electric drive slewing system of an electric excavator, characterized in that, Include: The model building module is used to perform dynamic modeling on the electric drive slewing system of an excavator and obtain a dynamic model. The controller module is used to select system state variables based on the dynamic model and to build a non-singular fast terminal sliding mode speed controller with the control objective of minimizing the tracking error of the overall machine rotation speed and minimizing the torque impact. The moment of inertia module is used to simplify the excavator structure by establishing a spatial coordinate system and a DH method coordinate system, and then constructing a mathematical model of the center of gravity of the working device and the moment of inertia that changes with the posture, so as to obtain the mathematical model of the total moment of inertia of the excavator. The update module is used to build a Luneburger observer to address disturbances caused by load changes and time-varying inertia during the excavator's swing operation, and feeds the observed load values ​​forward to the swing speed controller to obtain updated control data.

9. An electric excavator, characterized in that, It includes a processor, a memory, and a computer program stored in the memory; the computer program can be executed by the processor to implement a control method for the electric drive slewing system of an electric excavator as described in any one of claims 1 to 7.

10. A computer-readable storage medium, characterized in that, The computer-readable storage medium includes a stored computer program, wherein, when the computer program is executed, it controls the device where the computer-readable storage medium is located to perform a control method for the electric drive slewing system of an electric excavator as described in any one of claims 1 to 7.

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