An electric slewing control system and method

Abstract

This invention relates to an electric slewing control system and method, belonging to the field of new energy construction machinery. The system includes a tilt sensor mounted on the turntable of the excavator to detect the real-time tilt angle of the turntable; a slewing angle sensor mounted on the turntable to detect the slewing angle and direction of rotation; a slewing drive including a slewing motor assembly that drives the turntable to rotate via a meshing slewing gear; and a controller for calculating the slewing torque of the slewing motor assembly using a piecewise PID algorithm and sending control commands to the slewing motor assembly. The parameters of the PID algorithm are determined based on the real-time tilt angle, the slewing direction, and the slewing angle. This invention uses the tilt sensor and the turntable angle sensor to determine the slewing area of ​​the turntable, and determines the control parameters based on the slewing area and the real-time tilt angle, thereby improving the response performance of the turntable at different slewing positions.

Description

Technical Field

[0001] This invention relates to an electric rotary control system and method, belonging to the field of new energy engineering machinery. Background Technology

[0002] Excavators are one of the most important pieces of construction machinery, and their market share continues to grow, with the electrification of excavators accelerating. Currently, most electric excavators utilize a conversion from gasoline to electric power, where an electric motor replaces the engine while the traditional hydraulic system remains unchanged, resulting in improved overall machine efficiency compared to gasoline-powered models. The electrification of excavators has driven the application of electric slewing technology. Compared to traditional hydraulic motor-driven slewing systems, electric slewing offers higher transmission efficiency and allows for regenerative braking, further enhancing the excavator's operational efficiency.

[0003] Slope operation is a common working condition for excavators. During the slewing process, the tilting resistance torque will switch between slewing assist and slewing resistance as the slewing position changes, and the magnitude of the torque will also change with the position, which directly affects the responsiveness of the slewing action when operating on slopes. Summary of the Invention

[0004] The purpose of this invention is to provide an electric slewing control system and method, which uses the real-time tilt angle detected by the tilt angle sensor and the slewing angle and slewing direction detected by the slewing angle sensor to determine the slewing area of ​​the turntable in real time, and to correct and adjust the parameters of the PID algorithm in real time, so as to achieve the goal of maintaining good slewing response performance of the turntable at different slewing positions.

[0005] To achieve the above objectives, the present invention is implemented using the following technical solution.

[0006] In a first aspect, the present invention provides an electric slewing control system for an excavator, comprising:

[0007] A tilt sensor is installed on the turntable of the excavator and is used to detect the real-time tilt angle of the turntable;

[0008] A rotation angle sensor is mounted on the turntable and is used to detect the rotation angle and rotation direction of the turntable;

[0009] A rotary drive, including a rotary motor assembly, the rotary motor assembly being used to drive the turntable to rotate;

[0010] A speed handle is communicatively connected to the rotary motor assembly, and the speed handle is used to determine the target rotational speed of the rotary motor assembly;

[0011] The controller is configured to receive the actual rotational speed fed back by the rotary motor assembly and the target rotational speed determined by the speed handle; and to calculate the rotational torque of the rotary motor assembly using a PID algorithm based on the actual rotational speed and the target rotational speed; wherein the parameters of the PID algorithm are determined based on the real-time tilt angle, the rotational direction, and the rotational angle.

[0012] Optionally, the tilt sensor is located within the projection area of ​​the excavator's boom on the turntable.

[0013] Optionally, the formula for calculating the rotational torque of the rotary motor assembly using the PID algorithm is as follows:

[0014]

[0015] In the formula, T d (k) represents the rotational torque in the k-th control cycle; ∆Spd(i) represents the speed difference between the target rotational speed and the actual rotational speed in the ith control cycle; ∆Spd(k) and ∆Spd(k-1) represent the speed differences between the target rotational speed and the actual rotational speed in the k-th and k-1-th control cycles, respectively; and P, I, and D represent the proportional, integral, and derivative parameters of the PID algorithm, respectively.

[0016] Optionally, the parameters of the PID algorithm are determined based on the real-time tilt angle, the rotation direction, and the rotation angle, including:

[0017] During the rotation of the turntable, whenever the sign of the real-time tilt angle changes, the rotation angle is reset to zero and remeasured.

[0018] If the absolute value of the real-time tilt angle is less than or equal to a preset threshold, the parameters of the PID algorithm are the preset default values;

[0019] If the absolute value of the real-time tilt angle is greater than a preset threshold, the slewing region is determined based on the sign transformation type of the real-time tilt angle, the slewing direction, and the slewing angle. Based on the slewing region and the absolute value of the real-time tilt angle, the parameters of the PID algorithm are determined by looking up a table.

[0020] Optionally, the tilt sensor is a two-axis tilt sensor, the detection axes of the tilt sensor include mutually orthogonal X-axis and Y-axis, and the real-time tilt angle includes X-axis tilt angle and Y-axis tilt angle.

[0021] Optionally, when the turntable rotates, the sign of the X-axis tilt angle changes when the positive direction of the X-axis crosses a preset reference direction; the sign of the Y-axis tilt angle changes when the positive direction of the Y-axis crosses a preset reference direction; the absolute value of the real-time tilt angle is the larger of the absolute values ​​of the X-axis tilt angle and the Y-axis tilt angle.

[0022] Optionally, the turntable is characterized in that if the absolute value of the real-time tilt angle is greater than a preset threshold, the turntable operates within a preset zero speed range for a preset duration, or the rotary motor assembly malfunctions, the turntable executes a parking lock command and stops rotating.

[0023] Optionally, within the ramp plane, direction one is defined as the upward direction of the ramp, with the rotation center of the turntable as the starting point; direction two, direction three, and direction four are obtained by rotating direction one counterclockwise by 90°, 180°, and 270°, respectively, with the rotation center as the rotation center; the preset reference directions include direction two and direction four.

[0024] Optionally, the rotation area includes Region 1, Region 2, Region 3, and Region 4, which are distributed circumferentially around the rotation center; Region 1 includes a fan-shaped region within a first preset angle on both sides of the first direction, Region 2 includes a fan-shaped region within a second preset angle on both sides of the second direction, Region 3 includes a fan-shaped region within a first preset angle on both sides of the third direction, and Region 4 includes a fan-shaped region within a second preset angle on both sides of the fourth direction; the sum of the first preset angle and the second preset angle is equal to 90°.

[0025] Optionally, determining the gyration region based on the sign transformation type of the real-time tilt angle, the gyration direction, and the gyration angle includes:

[0026] When the rotation direction is counterclockwise:

[0027] If the Y-axis tilt angle changes from positive to negative, and the rotation angle is less than the first preset angle, the rotation area is determined to be area one; if the rotation angle is greater than the first preset angle, the rotation area is determined to be area two.

[0028] If the X-axis tilt angle changes from positive to negative, and the rotation angle is less than the second preset angle, the rotation area is determined to be area two; if the rotation angle is greater than the second preset angle, the rotation area is determined to be area three.

[0029] If the Y-axis tilt angle changes from negative to positive, and the rotation angle is less than the first preset angle, the rotation region is determined to be region three; if the rotation angle is greater than the first preset angle, the rotation region is determined to be region four.

[0030] If the X-axis tilt angle changes from negative to positive, and the rotation angle is less than the second preset angle, the rotation area is determined to be area four; if the rotation angle is greater than the second preset angle, the rotation area is determined to be area one.

[0031] When the rotation direction is clockwise:

[0032] If the Y-axis tilt angle changes from negative to positive, and the rotation angle is less than the first preset angle, the rotation area is determined to be area one; if the rotation angle is greater than the first preset angle, the rotation area is determined to be area four.

[0033] If the X-axis tilt angle changes from positive to negative, and the rotation angle is less than the second preset angle, the rotation area is determined to be area four; if the rotation angle is greater than the second preset angle, the rotation area is determined to be area three.

[0034] If the Y-axis tilt angle changes from positive to negative, and the rotation angle is less than the first preset angle, the rotation region is determined to be region three; if the rotation angle is greater than the first preset angle, the rotation region is determined to be region two.

[0035] If the X-axis tilt angle changes from negative to positive, and the rotation angle is less than the second preset angle, the rotation area is determined to be area two; if the rotation angle is greater than the second preset angle, the rotation area is determined to be area one.

[0036] Compared with the prior art, the beneficial effects achieved by the present invention are as follows:

[0037] 1. This invention proposes an electric slewing control system and method based on position estimation for electric excavators operating on slopes. The invention calculates slewing torque based on a piecewise PID algorithm. During slewing operations, the real-time tilt angle, slewing direction, and slewing angle can be used to estimate the slewing area of ​​the turntable relative to the slope, thereby determining the parameters of the corresponding PID algorithm, ensuring that the turntable maintains good response performance in different slewing areas.

[0038] 2. When the excavator's boom direction is estimated to be consistent with the slope direction (the positive Y-axis direction of the tilt sensor crosses direction two or four), the present invention clears the torque integral term, thereby quickly responding to the change in the required slewing torque caused by the switching of the tilt resistance torque direction. This allows the slewing system to maintain good responsiveness in different slewing areas, solving the problem of inconsistent slewing response caused by changes in the slewing tilt resistance torque corresponding to different slewing areas and different slope angles when working on slopes.

[0039] 3. This invention addresses the problem of potential malfunctions or other motor failures caused by slewing motor stalling during slope operations. By setting a stall time (the actual running time within the zero speed range) and a motor failure trigger condition (failure of the slewing motor assembly), the parking brake is activated to prevent malfunctions from causing uncontrolled slewing speed. Attached Figure Description

[0040] Figure 1 This is a schematic diagram of the control system in Example 1;

[0041] Figure 2 This is a schematic diagram showing the division of the turning area in Example 1;

[0042] Figure 3 This is a flowchart illustrating the control method in Example 1. Detailed Implementation

[0043] The technical solution of the present invention will be described in detail below with reference to the accompanying drawings and specific embodiments. It should be understood that the embodiments of the present invention and the specific features in the embodiments are detailed descriptions of the technical solution of the present invention, rather than limitations thereof. In the absence of conflict, the embodiments of the present invention and the technical features in the embodiments can be combined with each other.

[0044] The term "and / or" simply describes the relationship between related objects, indicating that three relationships can exist. For example, A and / or B can represent: A alone, A and B simultaneously, or B alone. Additionally, the character " / " generally indicates that the preceding and following related objects have an "or" relationship. Example 1

[0045] This embodiment describes an electric swing control system for an excavator, the structure of which is shown in the attached figure. Figure 1 As shown, it includes a tilt sensor, a slewing angle sensor, a slewing drive, and a controller. The tilt sensor is mounted on the excavator's turntable and is used to detect the real-time tilt angle of the turntable; the tilt sensor is located within the projection area of ​​the excavator's boom on the turntable. The slewing angle sensor is mounted on the excavator's turntable and is used to detect the slewing angle and slewing direction of the turntable. The slewing drive includes a slewing motor assembly, which drives the turntable to rotate through a meshing slewing gear; the controller is used to calculate the slewing torque of the slewing motor assembly using a piecewise PID algorithm and send control commands to the slewing motor assembly, the PID algorithm parameters being determined based on the real-time tilt angle, the slewing direction, and the slewing angle.

[0046] The slewing drive also includes a battery and a speed handle, with the battery serving as the system's power source. The slewing motor assembly is a component assembly integrating a motor, motor controller, reducer, and electromagnetic brake. The slewing motor assembly can receive and execute the slewing torque and parking commands sent by the controller, and provide feedback to the controller on the actual slewing speed and fault information.

[0047] The speed handle is used to determine the target rotation speed of the rotary motor assembly. The speed handle has three opening ranges: center, left rotation, and right rotation. There is a preset correspondence between the handle opening and the target rotation speed. When the handle is in the center position, the target rotation speed is 0. Within the left or right rotation range, the larger the opening, the larger the target rotation speed. The controller receives the target rotation speed from the handle, as well as the rotation status information fed back from the tilt sensor, rotation angle sensor, and rotary motor assembly. After calculating using a piecewise PID algorithm, it sends rotation torque and electromagnetic braking commands to the rotary motor assembly.

[0048] In the calculation of the rotational torque of the rotary motor assembly using the PID algorithm, the formula for calculating the rotational torque is as follows:

[0049] ;

[0050] In the formula, T d (k) represents the rotational torque in the kth control cycle; ∆Spd(k) and ∆Spd(k-1) are the speed differences between the target rotational speed and the actual rotational speed in the kth and k-1th control cycles, respectively; P, I, and D are the parameters of the PID algorithm.

[0051] The control method of the electric rotary control system includes:

[0052] Step S1: When the excavator's turntable rotates on the ramp, the real-time tilt angle of the turntable is determined based on the tilt sensor. In a specific embodiment, the tilt sensor is a two-axis tilt sensor, whose detection axes include mutually orthogonal X-axis and Y-axis. During the turntable's rotation, the positive direction of the X-axis is consistent with the orientation of the boom, and the positive direction of the X-axis is rotated 90° counterclockwise to obtain the positive direction of the Y-axis. The real-time tilt angle includes the X-axis tilt angle and the Y-axis tilt angle. The X-axis tilt angle and the Y-axis tilt angle are the tilt angle of the turntable relative to the X-axis and the tilt angle relative to the Y-axis, respectively. When the turntable rotates, if the positive direction of the X-axis or Y-axis crosses a pre-set reference direction, the sign of the real-time tilt angle changes. The sign change of the real-time tilt angle is determined by zero-crossing detection of the corresponding tilt angle signal. The tilt sensor can also be a single-axis slope sensor to achieve zero-crossing detection within a 180° range.

[0053] Step S2: During the turntable rotation, whenever the sign of the real-time tilt angle changes, the rotation angle is reset to zero and remeasured. In this embodiment, the rotation direction is determined by the rotation angle sensor and the rotation angle of the turntable is obtained from zero. The sign change of the real-time tilt angle (X-axis tilt angle and Y-axis tilt angle) can preliminarily determine the rotation orientation. Combined with the rotation direction and the rotation angle measured from zero, the rotation position can be accurately determined.

[0054] Step S3: If the absolute value of the real-time tilt angle is less than or equal to a preset threshold, the PID algorithm parameters are preset default values; the absolute value of the real-time tilt angle is the larger of the absolute values ​​of the X-axis tilt angle and the Y-axis tilt angle, and the default values ​​of the P, I, and D parameters are 8 / 1 / 0.5.

[0055] Step S4: If the absolute value of the real-time tilt angle is greater than a preset threshold, determine the slewing area based on the sign transformation type of the real-time tilt angle, the slewing direction, and the slewing angle.

[0056] The following is an explanation using a specific embodiment: In the plane of the ramp, the direction upward along the ramp, with the rotation center of the turntable as the starting point, is direction one; with the rotation center as the rotation center, direction one is rotated counterclockwise by 90°, 180° and 270° to obtain direction two, direction three and direction four respectively; the preset reference directions include direction two and direction four.

[0057] Combined with appendix Figure 2 When the projection area of ​​the boom's swing position on the ramp coincides with direction one, the positive X-axis direction of the tilt sensor also coincides with direction one. That is, the positive X-axis direction of the tilt sensor maintains the same direction as the projection area of ​​the boom's swing position on the ramp. Rotating the positive X-axis direction of the tilt sensor 90° counterclockwise gives the positive Y-axis direction. When the positive X-axis or positive Y-axis direction counterclockwise crosses direction two or four, the positive direction of the axis points towards the bottom of the ramp, and the sign of the tilt angle is negative; the same applies clockwise. The specific types of sign changes for the X-axis and Y-axis tilt angles are listed in Table 1 below:

[0058] Table 1. Correspondence between rotation position and zero-crossing detection

[0059]

[0060] Further, the rotation area includes Region 1, Region 2, Region 3, and Region 4, which are sequentially distributed around the rotation center. Region 1 includes a fan-shaped region within a first preset angle on both sides of direction 1; Region 2 includes a fan-shaped region within a second preset angle on both sides of direction 2; Region 3 includes a fan-shaped region within a first preset angle on both sides of direction 3; and Region 4 includes a fan-shaped region within a second preset angle on both sides of direction 4. The sum of the first preset angle and the second preset angle is equal to 90°. (Appendix) Figure 2 The first preset angle and the second preset angle are both 45°.

[0061] Combining Table 1 and Figure 2 The step of determining the gyration region based on the sign transformation type of the real-time tilt angle, the gyration direction, and the gyration angle includes:

[0062] When the rotation direction is counterclockwise:

[0063] If the Y-axis tilt angle changes from positive to negative, and the rotation angle is less than the first preset angle, the rotation area is determined to be area one; if the rotation angle is greater than the first preset angle, the rotation area is determined to be area two.

[0064] If the X-axis tilt angle changes from positive to negative, and the rotation angle is less than the second preset angle, the rotation area is determined to be area two; if the rotation angle is greater than the second preset angle, the rotation area is determined to be area three.

[0065] If the Y-axis tilt angle changes from negative to positive, and the rotation angle is less than the first preset angle, the rotation region is determined to be region three; if the rotation angle is greater than the first preset angle, the rotation region is determined to be region four.

[0066] If the X-axis tilt angle changes from negative to positive, and the rotation angle is less than the second preset angle, the rotation area is determined to be area four; if the rotation angle is greater than the second preset angle, the rotation area is determined to be area one.

[0067] When the rotation direction is clockwise:

[0068] If the Y-axis tilt angle changes from negative to positive, and the rotation angle is less than the first preset angle, the rotation area is determined to be area one; if the rotation angle is greater than the first preset angle, the rotation area is determined to be area four.

[0069] If the X-axis tilt angle changes from positive to negative, and the rotation angle is less than the second preset angle, the rotation area is determined to be area four; if the rotation angle is greater than the second preset angle, the rotation area is determined to be area three.

[0070] If the Y-axis tilt angle changes from positive to negative, and the rotation angle is less than the first preset angle, the rotation area is determined to be area three; if the rotation angle is greater than the first preset angle, the rotation area is determined to be area two.

[0071] If the X-axis tilt angle changes from negative to positive, and the rotation angle is less than the second preset angle, the rotation area is determined to be area two; if the rotation angle is greater than the second preset angle, the rotation area is determined to be area one.

[0072] Step S5: Determine the PID algorithm parameters by looking up the table based on the absolute values ​​of the turning area and the real-time tilt angle. In a specific embodiment, refer to Table 2 below:

[0073] Table 2. Correspondence between the absolute values ​​of the turning range, real-time tilt angle, and PID algorithm parameters.

[0074]

[0075] The absolute value of the real-time tilt angle in Table 2 is the larger of the X-axis tilt angle and the Y-axis tilt angle. Multiple intervals with progressively increasing absolute values ​​for the real-time tilt angle are pre-defined. The parameters for the corresponding PID algorithm can be directly obtained by referring to the rotation region and determining which interval the absolute value of the real-time tilt angle belongs to.

[0076] For example, refer to Table 2. Figure 3 It should be noted that when the absolute value of the real-time tilt angle is ≤5° (preset threshold), the P, I, and D parameters of the PID algorithm all take the default values, which are 8 / 1 / 0.5.

[0077] If 5° < the absolute value of the real-time tilt angle ≤ 15° and the turning region is region one or region three, the parameters of the PID algorithm are 9 / 1.5 / 0.5.

[0078] If 5° < the absolute value of the real-time tilt angle ≤ 15° and the turning region is region two or region four, or 15° < the absolute value of the real-time tilt angle ≤ 30° and the turning region is region one or region three, the parameters of the PID algorithm are 10 / 2 / 0.5.

[0079] If 15° < the absolute value of the real-time tilt angle ≤ 30° and the turning region is region two or region four, or if the absolute value of the real-time tilt angle > 30° and the turning region is region one or region three, the parameters of the PID algorithm are 11 / 2.5 / 0.5.

[0080] If the absolute value of the real-time tilt angle is greater than 30° and the turning region is region two or region four, the parameters of the PID algorithm are 12 / 3 / 0.5. Example 2

[0081] Similar to Embodiment 1, the control method further includes: when the sign of the Y-axis tilt angle changes (i.e. when the Y-axis signal crosses zero), determining the rotational torque required to eliminate the speed difference based on the actual rotational speed fed back by the rotary motor assembly and the target rotational speed determined by the speed handle;

[0082] Specifically, when the sign of the Y-axis tilt angle changes (i.e., when the Y-axis signal crosses zero), it indicates that the current rotation position is either upward or downward along the ramp. At the next moment, the tilt resistance torque relative to the current rotation direction will switch between resistance and assist. To reduce the impact of the accumulated torque of the integral term on the response, the torque closed-loop integral term is first cleared. The current rotation speed is calculated based on the target rotation speed corresponding to the rotation handle and the current actual rotation speed fed back from the rotation motor assembly. k Speed ​​difference per control cycle ∆Spd ( k ).

[0083] The required motor rotation torque to eliminate the speed difference is calculated using a PID algorithm. The formula for calculating the motor rotation torque is as follows:

[0084]

[0085] In the formula, T d (k) represents the slewing torque in the kth control cycle; ∆Spd(k) and ∆Spd(k-1) are the speed differences between the target slewing speed and the actual slewing speed of the slewing motor assembly in the kth and (k-1)th control cycles, respectively; P, I, and D are the parameters of the PID algorithm, and the values ​​of P, I, and D are determined by looking up the absolute values ​​of the slewing region and the real-time tilt angle in a table. Example 3

[0086] Similar to Embodiment 1, the control method further includes: if the absolute value of the real-time tilt angle is greater than a preset threshold, the turntable operates within a preset zero speed range for a preset duration, or the rotary motor assembly malfunctions, the turntable executes a parking lock command and stops rotating.

[0087] Specifically, when operating on a slope, to prevent the motor from stalling for an extended period at 0 speed, which could lead to a malfunction and loss of control over the slewing speed, or other motor malfunctions causing loss of control over the slewing speed, the parking lock brake is activated when a prolonged stall or motor malfunction is detected. The specific control strategy is as follows:

[0088] Condition 1: At least one of the absolute values ​​of the X-axis tilt angle and the Y-axis tilt angle is >5°;

[0089] Condition 2: The target rotation speed corresponding to the speed handle is 0, and the current actual rotation speed has been within the zero speed range for more than 10 seconds. The zero speed range can usually be set to [-10, 10].

[0090] Condition 3: The turntable experiences a rotational failure, or the rotary motor assembly or controller malfunctions;

[0091] If either condition one or condition three is met, the control command for the motor torque (slewing torque, slewing torque) will be cleared to zero, and the turntable will execute the parking lock command and stop rotating.

[0092] Those skilled in the art will understand that embodiments of the present invention can be provided as methods, systems, or computer program products. Therefore, the present invention can take the form of a completely hardware embodiment, a completely software embodiment, or an embodiment combining software and hardware aspects. Furthermore, the present invention can take the form of a computer program product embodied on one or more computer-usable storage media (including, but not limited to, disk storage, CD-ROM, optical storage, etc.) containing computer-usable program code.

[0093] This invention is described with reference to flowchart illustrations and / or block diagrams of methods, apparatus (systems), and computer program products according to embodiments of the invention. It will be understood that each block of the flowchart illustrations and / or block diagrams, and combinations of blocks in the flowchart illustrations and / or block diagrams, can be implemented by computer program instructions. These computer program instructions can be provided to a processor of a general-purpose computer, special-purpose computer, embedded processor, or other programmable data processing apparatus to produce a machine, such that the instructions, which execute via the processor of the computer or other programmable data processing apparatus, generate instructions for implementing the flowchart illustrations and / or block diagrams. Figure 1 One or more processes and / or boxes Figure 1 A device that provides the functions specified in one or more boxes.

[0094] These computer program instructions may also be stored in a computer-readable storage medium that can direct a computer or other programmable data processing device to function in a particular manner, such that the instructions stored in the computer-readable storage medium produce an article of manufacture including instruction means, which are implemented in a process Figure 1 One or more processes and / or boxes Figure 1 The function specified in one or more boxes.

[0095] These computer program instructions may also be loaded onto a computer or other programmable data processing equipment to cause a series of operational steps to be performed on the computer or other programmable equipment to produce a computer-implemented process, thereby providing instructions that execute on the computer or other programmable equipment for implementing the process. Figure 1 One or more processes and / or boxes Figure 1 The steps of the function specified in one or more boxes.

[0096] The embodiments of the present invention have been described above with reference to the accompanying drawings. However, the present invention is not limited to the specific embodiments described above. The specific embodiments described above are merely illustrative and not restrictive. Those skilled in the art can make many other forms under the guidance of the present invention without departing from the spirit and scope of the claims. All of these forms are within the protection scope of the present invention.

Claims

1. An electric swing control system for an excavator, characterized in that, include: A tilt sensor is installed on the turntable of the excavator and is used to detect the real-time tilt angle of the turntable; A rotation angle sensor is mounted on the turntable and is used to detect the rotation angle and rotation direction of the turntable; A rotary drive, including a rotary motor assembly, the rotary motor assembly being used to drive the turntable to rotate; A speed handle is communicatively connected to the rotary motor assembly, and the speed handle is used to determine the target rotational speed of the rotary motor assembly; The controller is configured to receive the actual rotational speed fed back by the rotary motor assembly and the target rotational speed determined by the speed handle; and to calculate the rotational torque of the rotary motor assembly using a PID algorithm based on the actual rotational speed and the target rotational speed; wherein the parameters of the PID algorithm are determined based on the real-time tilt angle, the rotational direction, and the rotational angle. The parameters of the PID algorithm are determined based on the real-time tilt angle, the rotation direction, and the rotation angle, including: During the rotation of the turntable, whenever the sign of the real-time tilt angle changes, the rotation angle is reset to zero and remeasured. If the absolute value of the real-time tilt angle is less than or equal to a preset threshold, the parameters of the PID algorithm are the preset default values; If the absolute value of the real-time tilt angle is greater than a preset threshold, the slewing region is determined according to the sign transformation type of the real-time tilt angle, the slewing direction, and the slewing angle. The parameters of the PID algorithm are determined by looking up a table based on the slewing region and the absolute value of the real-time tilt angle. The tilt sensor is a two-axis tilt sensor, and the detection axes of the tilt sensor include mutually orthogonal X-axis and Y-axis. The real-time tilt angle includes the X-axis tilt angle and the Y-axis tilt angle. When the turntable rotates, the X-axis tilt angle changes sign when the positive direction of the X-axis crosses the preset reference direction; the Y-axis tilt angle changes sign when the positive direction of the Y-axis crosses the preset reference direction; the absolute value of the real-time tilt angle is the larger of the absolute values ​​of the X-axis tilt angle and the Y-axis tilt angle.

2. The excavator electric swing control system according to claim 1, characterized in that, The tilt sensor is located within the projection area of ​​the excavator's boom on the turntable.

3. The excavator electric swing control system according to claim 1, characterized in that, The formula for calculating the rotational torque of the rotary motor assembly using the PID algorithm is as follows: ； In the formula, T d (k) represents the rotational torque in the k-th control cycle; ∆Spd(i) represents the speed difference between the target rotational speed and the actual rotational speed in the ith control cycle; ∆Spd(k) and ∆Spd(k-1) represent the speed differences between the target rotational speed and the actual rotational speed in the k-th and k-1-th control cycles, respectively; and P, I, and D represent the proportional, integral, and derivative parameters of the PID algorithm, respectively.

4. The excavator electric swing control system according to claim 1, characterized in that, If the absolute value of the real-time tilt angle is greater than a preset threshold, the turntable operates within a preset zero speed range for a preset duration, or the rotary motor assembly malfunctions, the turntable executes a parking lock command and stops rotating.

5. The excavator electric swing control system according to claim 4, characterized in that, Within the ramp plane, direction one is defined as the upward direction of the ramp, with the rotation center of the turntable as the starting point; direction two, direction three, and direction four are obtained by rotating direction one counterclockwise by 90°, 180°, and 270°, respectively, with the rotation center as the rotation center; the preset reference directions include direction two and direction four.

6. The excavator electric swing control system according to claim 5, characterized in that, The rotation area includes Region 1, Region 2, Region 3, and Region 4, which are distributed circumferentially around the rotation center. Region 1 includes a fan-shaped region within a first preset angle on both sides of the first direction. Region 2 includes a fan-shaped region within a second preset angle on both sides of the second direction. Region 3 includes a fan-shaped region within a first preset angle on both sides of the third direction. Region 4 includes a fan-shaped region within a second preset angle on both sides of the fourth direction. The sum of the first preset angle and the second preset angle is equal to 90°.

7. The excavator electric swing control system according to claim 6, characterized in that, Determining the gyration region based on the sign transformation type of the real-time tilt angle, the gyration direction, and the gyration angle includes: When the rotation direction is counterclockwise: If the Y-axis tilt angle changes from positive to negative, and the rotation angle is less than the first preset angle, the rotation area is determined to be area one; if the rotation angle is greater than the first preset angle, the rotation area is determined to be area two. If the X-axis tilt angle changes from positive to negative, and the rotation angle is less than the second preset angle, the rotation area is determined to be area two; if the rotation angle is greater than the second preset angle, the rotation area is determined to be area three. If the Y-axis tilt angle changes from negative to positive, and the rotation angle is less than the first preset angle, the rotation region is determined to be region three; if the rotation angle is greater than the first preset angle, the rotation region is determined to be region four. If the X-axis tilt angle changes from negative to positive, and the rotation angle is less than the second preset angle, the rotation area is determined to be area four; if the rotation angle is greater than the second preset angle, the rotation area is determined to be area one. When the rotation direction is clockwise: If the Y-axis tilt angle changes from negative to positive, and the rotation angle is less than the first preset angle, the rotation area is determined to be area one; if the rotation angle is greater than the first preset angle, the rotation area is determined to be area four. If the X-axis tilt angle changes from positive to negative, and the rotation angle is less than the second preset angle, the rotation area is determined to be area four; if the rotation angle is greater than the second preset angle, the rotation area is determined to be area three. If the Y-axis tilt angle changes from positive to negative, and the rotation angle is less than the first preset angle, the rotation region is determined to be region three; if the rotation angle is greater than the first preset angle, the rotation region is determined to be region two. If the X-axis tilt angle changes from negative to positive, and the rotation angle is less than the second preset angle, the rotation area is determined to be area two; if the rotation angle is greater than the second preset angle, the rotation area is determined to be area one.

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