Rotary control method and device and engineering machinery

Abstract

The invention provides a rotation control method and device and engineering machinery, and relates to the technical field of engineering machinery control. The method comprises the steps that in response to a rotation braking instruction, a motor connected with a rotation platform is controlled to brake the rotation platform; controlling the electric braking torque of a motor to decrease progressively along with time and controlling the mechanical braking torque of a mechanical brake to increase progressively along with time in response to the rotating speed of the revolving platform smaller than or equal to a first rotating speed threshold and the current electric braking torque smaller than or equal to a torque threshold; in response to the situation that the absolute value of the error between the target braking position and the current position of the rotating platform is smaller than or equal to the first position error threshold value and larger than the second position error threshold value and the rotating speed of the rotating platform is smaller than or equal to the second rotating speed threshold value, a motor is controlled to brake the rotating platform based on the target electric braking torque, the target electric braking torque is obtained based on the error; and controlling the mechanical brake to perform locking operation in response to the fact that the absolute value of the error is smaller than or equal to the second position error threshold.

Description

Technical Field

[0001] This disclosure relates to the field of engineering machinery control technology, and more specifically, to a slewing control method, device, and engineering machinery. Background Technology

[0002] Construction machinery (such as excavators) is widely used in various construction projects. The slewing platform of construction machinery plays an important role in these projects, enabling the machinery to operate and position itself flexibly to complete the tasks. Summary of the Invention

[0003] In related technologies, during the slewing braking process of the slewing platform of construction machinery, the large moment of inertia can easily lead to inertial drift and unstable stopping, resulting in a large randomness in the stopping position of the slewing platform and inaccurate stopping.

[0004] To address the aforementioned problems, the present disclosure proposes the following solutions.

[0005] According to one aspect of the present disclosure, a slewing control method is provided, comprising: in response to a slewing braking command indicating a target braking position, controlling a motor connected to a slewing platform to brake the slewing platform; in response to the slewing platform's rotational speed being less than or equal to a first rotational speed threshold and the motor's current electric braking torque being less than or equal to a torque threshold, controlling the motor's electric braking torque to decrease from the current electric braking torque over time and controlling a mechanical braking torque of a mechanical brake connected to the slewing platform to increase over time; in response to the absolute value of the error between the target braking position and the slewing platform's current position being less than or equal to a first position error threshold and greater than a second position error threshold, and the slewing platform's rotational speed being less than or equal to the second rotational speed threshold, controlling the motor to brake the slewing platform based on a target electric braking torque, wherein the target electric braking torque is obtained based on the error, the second rotational speed threshold is less than the first rotational speed threshold, and the second position error threshold is less than the first position error threshold; and in response to the absolute value of the error being less than or equal to the second position error threshold, controlling the mechanical brake to perform a locking operation to stop the slewing platform from moving.

[0006] In some embodiments, the electric braking torque of the motor decreases linearly over time from the current electric braking torque based on a first slope, wherein the first slope is negative; and the mechanical braking torque of the mechanical brake increases linearly over time based on a second slope, wherein the second slope is positive.

[0007] In some embodiments, the first slope and the second slope are opposite numbers.

[0008] In some embodiments, when the first moment of inertia of the rotary platform is greater than or equal to a preset moment of inertia threshold, the absolute value of the first slope is a first slope value, and the second slope is a second slope value; and when the first moment of inertia is less than the preset moment of inertia threshold, the absolute value of the first slope is a third slope value, and the second slope is a fourth slope value, wherein the third slope value is greater than the first slope value, and the fourth slope value is greater than the second slope value.

[0009] In some embodiments, the slewing control method further includes: in response to the absolute value of the error between the target braking position and the current position of the slewing platform being less than or equal to a first position error threshold and greater than a second position error threshold, and the rotational speed of the slewing platform being less than or equal to a second rotational speed threshold, further controlling the mechanical braking torque of the mechanical brake to remain at the current mechanical braking torque.

[0010] In some embodiments, when the rotational speed of the rotary platform is greater than the first rotational speed threshold, or when the current electric braking torque of the motor is greater than the torque threshold, the mechanical braking torque of the mechanical brake is zero.

[0011] In some embodiments, the slewing control method further includes: in response to the slewing platform's rotational speed being less than or equal to a first rotational speed threshold, and the motor's current electric braking torque being greater than the torque threshold, controlling the motor's electric braking torque to decrease.

[0012] In some embodiments, controlling a motor connected to the rotary platform to brake the rotary platform in response to a rotary braking command indicating a target braking position includes: in response to the rotary braking command indicating a target braking position, obtaining a feedforward braking torque of the motor based on a preset angular deceleration and a first moment of inertia of the rotary platform, and controlling the motor to brake the rotary platform based on the feedforward braking torque.

[0013] In some embodiments, the preset angular deceleration is the maximum safe angular deceleration of the rotary platform.

[0014] In some embodiments, when the absolute value of the error is greater than a first threshold, the target electric braking torque is obtained based on the error and a first closed-loop control parameter; when the absolute value of the error is greater than a second threshold and less than or equal to the first threshold, the target electric braking torque is obtained based on the error and a second closed-loop control parameter; when the absolute value of the error is less than or equal to the second threshold, the target electric braking torque is obtained based on the error and a third closed-loop control parameter, wherein the value of at least one parameter in the second closed-loop control parameter is smaller than the value of a corresponding at least one parameter in the first closed-loop control parameter, and the value of at least one parameter in the third closed-loop control parameter is smaller than the value of a corresponding at least one parameter in the second closed-loop control parameter.

[0015] In some embodiments, the slewing control method further includes: in response to the absolute value of the error being less than or equal to a second position error threshold, controlling the motor to disengage from braking the slewing platform.

[0016] According to another aspect of the present disclosure, a slewing control device is provided, comprising: a module configured to perform the slewing control method described in any of the above embodiments.

[0017] According to another aspect of the present disclosure, a slewing control device is provided, comprising: a memory; and a processor coupled to the memory, configured to execute the slewing control method described in any of the above embodiments based on instructions stored in the memory.

[0018] According to another aspect of the present disclosure, an engineering machine is provided, including: the slewing control device described in any of the above embodiments.

[0019] According to another aspect of the present disclosure, a computer-readable storage medium is provided, including a computer program, wherein when the computer program is executed by a processor, it implements the steps of the rotation control method described in any of the above embodiments.

[0020] According to another aspect of the present disclosure, a computer program product is provided, including a computer program, wherein when the computer program is executed by a processor, it implements the steps of the rotary control method described in any of the above embodiments.

[0021] In this embodiment, a smooth transition from electric braking to mechanical braking is achieved by controlling the electric braking torque to decrease over time and the mechanical braking torque to increase over time. During the transition, the slewing platform brakes under the synergistic effect of electric and mechanical braking, avoiding the torque abrupt change caused by a direct switch from electric to mechanical braking, reducing torque impact, and improving the smoothness of the braking process. Furthermore, by finely adjusting the braking torque based on the current position error to stop the slewing platform at the desired position, the possibility of braking drift can be reduced, improving parking smoothness and parking accuracy.

[0022] Other features and advantages of this disclosure will become clearer from the following detailed description of exemplary embodiments with reference to the accompanying drawings. Attached Figure Description

[0023] The accompanying drawings, which form part of this specification, illustrate embodiments of this disclosure and, together with the specification, serve to explain the principles of this disclosure.

[0024] This disclosure will become clearer with reference to the accompanying drawings and the following detailed description, wherein:

[0025] Figure 1 A schematic flowchart of a slewing control method according to some embodiments of the present disclosure is shown;

[0026] Figure 2 A schematic diagram of the process of coordinated braking of electric braking and mechanical braking according to some embodiments of the present disclosure is shown;

[0027] Figure 3 A schematic flowchart illustrating the process of adjusting electric braking torque by error according to some embodiments of the present disclosure is shown;

[0028] Figure 4 A schematic flowchart of a slewing control method according to some other embodiments of the present disclosure is shown;

[0029] Figure 5 A schematic diagram illustrating the variation of electric braking torque and mechanical braking torque over time according to some embodiments of the present disclosure is shown;

[0030] Figure 6 A schematic diagram of a slewing control device according to some embodiments of the present disclosure is shown;

[0031] Figure 7 A schematic diagram of a slewing control device according to other embodiments of the present disclosure is shown;

[0032] Figure 8 A schematic diagram of a slewing control system according to some embodiments of the present disclosure is shown;

[0033] Figure 9A schematic block diagram of a computer system on which embodiments of the present disclosure may be implemented is shown.

[0034] For ease of understanding, the positions, dimensions, and extents of the structures shown in the accompanying drawings and other materials may not represent actual positions, dimensions, and extents. Therefore, the disclosed invention is not limited to the positions, dimensions, and extents disclosed in the accompanying drawings and other materials. Furthermore, the drawings are not necessarily drawn to scale, and some features may be enlarged to show details of specific components. Detailed Implementation

[0035] Various exemplary embodiments of the present disclosure will now be described in detail with reference to the accompanying drawings. It should be noted that, unless otherwise specifically stated, the relative arrangement, numerical expressions, and values ​​of the components and steps set forth in these embodiments do not limit the scope of the present disclosure.

[0036] The following description of at least one exemplary embodiment is merely illustrative and is in no way intended to limit the scope of this disclosure or its application or use. That is, the structures and methods herein are shown in an exemplary manner to illustrate different embodiments of the structures and methods in this disclosure. However, those skilled in the art will understand that they merely illustrate exemplary ways that can be used to implement this disclosure, and not exhaustive ways. Furthermore, the drawings are not necessarily drawn to scale, and some features may be enlarged to show details of specific components.

[0037] Techniques, methods, and equipment known to those skilled in the art may not be discussed in detail, but where appropriate, such techniques, methods, and equipment should be considered part of the specification.

[0038] In all examples shown and discussed herein, any specific values ​​should be interpreted as merely exemplary and not as limitations. Therefore, other examples of exemplary embodiments may have different values.

[0039] Figure 1 This is a schematic flowchart of a slewing control method according to some embodiments of the present disclosure. For example... Figure 1 As shown, the slewing control method according to some embodiments of the present disclosure may include steps S110 to S140.

[0040] In step S110, in response to the slewing braking command indicating the target braking position, the motor connected to the slewing platform is controlled to brake the slewing platform.

[0041] Here, the slewing platform can have a large initial speed. Upon receiving a slewing braking command, the motor can be controlled to output the corresponding electric braking torque to brake the slewing platform and reduce its speed.

[0042] In step S120, in response to the rotational speed of the rotary platform being less than or equal to a first rotational speed threshold and the current electric braking torque of the motor being less than or equal to a torque threshold, the electric braking torque of the motor is controlled to decrease from the current electric braking torque over time, and the mechanical braking torque of the mechanical brake connected to the rotary platform is controlled to increase over time.

[0043] As one implementation method, when the rotational speed of the slewing platform exceeds a first speed threshold, or when the current electric braking torque of the motor exceeds a torque threshold, the mechanical braking torque of the mechanical brake can be zero to improve the smoothness of the braking process of the slewing platform. In other words, mechanical braking is only introduced when both conditions are met: the rotational speed of the slewing platform is less than or equal to the first speed threshold and the current electric braking torque of the motor is less than or equal to the torque threshold. This controls the mechanical braking torque of the mechanical brake to increase gradually from zero over time. This avoids the large impact caused by introducing mechanical braking at high speeds or high electric braking torques, which could lead to an unstable braking process for the slewing platform.

[0044] The torque threshold indicates the maximum electric braking torque threshold at which the mechanical brake can smoothly engage. That is, when the electric braking torque is less than or equal to the torque threshold, the mechanical brake can smoothly engage to provide a relatively stable mechanical braking torque. The first speed threshold can represent the speed threshold at which the mechanical brake engages; in some embodiments, the first speed threshold may be, for example, 100~200 r / min.

[0045] In step S130, in response to the absolute value of the error between the target braking position and the current position of the slewing platform being less than or equal to a first position error threshold and greater than a second position error threshold, and the rotational speed of the slewing platform being less than or equal to a second rotational speed threshold, the motor is controlled to brake the slewing platform based on the target electric braking torque.

[0046] Here, the target electric braking torque can be obtained based on the error between the target braking position and the current position of the slewing platform. The second speed threshold is less than the first speed threshold. As some embodiments, the second speed threshold is 3~5 r / min.

[0047] The first position error threshold represents the position error condition that triggers fine-tuning of the electric braking torque to achieve precise stopping. When the absolute value of the error between the target braking position and the current position of the turning platform is less than or equal to the first position error threshold, fine-tuning of the electric braking torque can be triggered. This allows for precise adjustment of the electric braking torque based on the current position error, thus contributing to precise stopping. The second position error threshold is less than the first position error threshold and represents the tolerance for determining stopping accuracy. If the absolute value of the error is less than or equal to the second position error threshold, the current position is considered the desired stopping position.

[0048] In some embodiments, considering that electric braking has a faster response than mechanical braking, and in response to the absolute value of the error between the target braking position and the current position of the rotary platform being less than or equal to a first position error threshold and greater than a second position error threshold, and the rotational speed of the rotary platform being less than or equal to a second rotational speed threshold, the mechanical braking torque of the mechanical brake can be controlled to remain at the current mechanical braking torque. That is, during the process of controlling the electric braking torque of the motor to decrease over time and controlling the mechanical braking torque to increase over time, if the absolute value of the error between the target braking position and the current position of the rotary platform is less than or equal to the first position error threshold and greater than the second position error threshold, and the rotational speed of the rotary platform is less than or equal to the second rotational speed threshold, then the control of increasing the mechanical braking torque over time can be stopped, and the mechanical braking torque can be controlled to remain at the current mechanical braking torque. Furthermore, the control of decreasing the electric braking torque over time can be stopped, and braking of the rotary platform based on the target electric braking torque can be stopped. Thus, by fixing the mechanical braking torque at its current value and finely adjusting the electric braking torque according to the current position error, it helps to improve parking accuracy.

[0049] In some embodiments, after the mechanical braking torque increases to the maximum mechanical braking torque over time, if the absolute value of the error between the target braking position and the current position of the rotary platform is still greater than the first position error threshold or the rotational speed of the rotary platform is still greater than the second rotational speed threshold, then the mechanical braking torque of the mechanical brake can be maintained at the maximum mechanical braking torque so that the absolute value of the error between the target braking position and the current position of the rotary platform is less than or equal to the first position error threshold and the rotational speed of the rotary platform is less than or equal to the second rotational speed threshold.

[0050] In step S140, in response to the absolute value of the error being less than or equal to the second position error threshold, the mechanical brake is controlled to perform a locking operation to stop the rotary platform from moving.

[0051] Here, when the absolute value of the error between the target braking position and the current position of the rotary platform is less than or equal to the second position error threshold, the rotary platform can be brought to a smooth and reliable stop and remain stationary by the locking operation of the mechanical brake.

[0052] In the above embodiments, under certain conditions, a smooth transition from electric braking to mechanical braking is achieved by controlling the electric braking torque to decrease over time and the mechanical braking torque to increase over time. During the transition, the slewing platform brakes under the combined action of electric and mechanical braking, avoiding the sudden torque change caused by directly switching from electric to mechanical braking, reducing torque impact, and improving the smoothness of the braking process. Furthermore, finely adjusting the braking torque based on the current position error to stop the slewing platform at the desired position reduces the possibility of braking drift and improves stopping smoothness and accuracy.

[0053] In some embodiments, in response to a slewing braking command indicating a target braking position, controlling a motor connected to the slewing platform to brake the slewing platform may include: in response to the slewing braking command indicating the target braking position, obtaining a feedforward braking torque of the motor based on a preset angular deceleration and a first moment of inertia of the slewing platform, and controlling the motor to brake the slewing platform based on the feedforward braking torque.

[0054] In this way, a feedforward braking torque adapted to the rotational inertia of the rotary platform can be obtained, and the rotary platform can be braked based on the feedforward braking torque adapted to the rotational inertia of the rotary platform, so that the motor can brake the rotary platform based on the electric braking torque adapted to the rotational inertia of the rotary platform.

[0055] Here, the preset angular deceleration can be greater than or equal to a preset threshold. In this way, a larger feedforward braking torque can be obtained based on a larger angular deceleration, thereby enabling braking based on a larger electric braking torque in the initial braking stage of the slewing platform.

[0056] As one implementation method, the preset angular deceleration can be the maximum safe angular deceleration of the slewing platform. In this way, the maximum possible electric braking torque can be obtained, thereby enabling braking based on the maximum possible electric braking torque, which helps to quickly dissipate the kinetic energy of the slewing platform and achieve rapid braking.

[0057] In some embodiments, the first moment of inertia of the rotary platform can be obtained based on the second moment of inertia of the motor rotor, the third moment of inertia of the reducer connected to the rotary platform, the fourth moment of inertia of the load, and the reduction ratio of the reducer. The motor is connected to the rotary platform through the reducer to electrically brake the rotary platform, and the mechanical brake is connected to the rotary platform through the reducer to mechanically brake the rotary platform.

[0058] As one implementation method, the first moment of inertia J_total of the rotary platform can be obtained based on the following formula:

[0059] J_total=J_motor+J_reduction+J_load(θ_boom,θ_arm,θ_bucket,m0) / i 2 Where J_motor is the second moment of inertia of the motor rotor; J_reduction is the third moment of inertia of the reducer; i is the reduction ratio of the reducer; J_load is the fourth moment of inertia of the load; J_load(θ_boom,θ_arm,θ_bucket,m0) means that J_load is obtained based on θ_boom, θ_arm, θ_bucket, and m0, where θ_boom is the boom joint angle, θ_arm is the stick joint angle, θ_bucket is the bucket joint angle, and m0 is the load weight in the bucket.

[0060] In some embodiments, the feedforward braking torque of the motor can be obtained based on the following formula:

[0061] T_ff = k_adaptive·J_total·α_max, where T_ff is the feedforward braking torque of the motor; k_adaptive is the gain coefficient; and α_max is the maximum safe angle deceleration. As some implementations, the gain coefficient can be adjusted according to the operating conditions to obtain a feedforward braking torque adapted to the current operating conditions.

[0062] In some embodiments, controlling the motor to brake the rotary platform based on the feedforward braking torque may include: having the current loop control unit adjust the motor current based on the feedforward braking torque so that the motor generates a first electric braking torque corresponding to the feedforward braking torque, so that the motor controls the rotary platform to brake based on the first electric braking torque.

[0063] As one implementation, the current loop control unit can obtain the first electric braking torque based on the error between the feedforward braking torque and the current electric braking torque, and the closed-loop control parameters of the current loop control unit (e.g., at least one of proportional gain, derivative gain, and integral gain). Thus, the current loop control unit can generate the corresponding first electric braking torque with relatively fine precision based on the feedforward braking torque.

[0064] In some embodiments, in response to the rotational speed of the slewing platform being greater than a first speed threshold, the slewing platform is continuously braked by a motor controlled by feedforward braking torque. Thus, when the rotational speed of the slewing platform is greater than the first speed threshold, the slewing platform can be continuously braked by a motor controlled by feedforward braking torque to reduce the rotational speed of the slewing platform until the rotational speed of the slewing platform is less than or equal to the first speed threshold. In some embodiments, in response to the current electric braking torque of the motor being greater than a torque threshold, the electric braking torque of the motor is controlled to decrease. As some implementations, a command instructing the reduction of the electric braking torque can be input to a current loop control unit, causing the current loop control unit to adjust the current based on the corresponding command to reduce the electric braking torque of the motor. Thus, when the current electric braking torque is greater than a torque threshold, the electric braking torque of the motor can be controlled to decrease until the current electric braking torque is less than or equal to the torque threshold.

[0065] In the above embodiments, considering that directly introducing mechanical braking when the current electric braking torque of the motor is large or the current speed of the rotary platform is large could easily cause mechanical damage and safety issues, the electric braking torque is reduced until it is less than or equal to a torque threshold when it is large, or the speed of the rotary platform is reduced until it is less than or equal to a first speed threshold when it is large. Thus, when both the speed of the rotary platform and the current electric braking torque of the motor are less than or equal to the first speed threshold are satisfied, the electric braking torque is controlled to decrease over time and the mechanical braking torque is controlled to increase over time, thereby allowing for a smooth, safe, and reliable introduction of mechanical braking, improving the stability of the braking process.

[0066] In some embodiments, the electric braking torque of the motor can decrease linearly over time based on a first slope. In some embodiments, the mechanical braking torque of the mechanical brake can increase linearly over time based on a second slope. Here, the first slope is negative and the second slope is positive. In this way, the electric braking torque can decrease linearly and the mechanical braking torque can increase linearly, thereby achieving a smooth and controllable transition from electric braking to mechanical braking.

[0067] As some implementations, in response to the rotational speed of the slewing platform being less than or equal to a first speed threshold and the current electric braking torque of the motor being less than or equal to a torque threshold, the electric braking torque at time t, starting from the current electric braking torque, can be expressed as follows: T_brake_electric(t) = T_current·(1–k1·t / t_blend); the mechanical braking torque at time t can be expressed as follows: T_brake_mechanical(t) = T_mech_max·(k2·t / t_blend).

[0068] Here, T_brake_electric(t) represents the electric braking torque at time t, starting from the point where the electric braking torque begins to decrease from the current electric braking torque; T_current represents the current electric braking torque, specifically, T_current is the current electric braking torque when the conditions are met that the rotational speed of the rotary platform is less than or equal to the first speed threshold and the current electric braking torque of the motor is less than or equal to the torque threshold; t_blend is a preset time, representing the preset total time for coordinated braking by electric braking and mechanical braking; T_brake_mechanical(t) represents the mechanical braking torque at time t, starting from the point where the mechanical braking torque begins to increase (i.e., starting from the point where the electric braking torque begins to decrease from the current electric braking torque); T_mech_max represents the maximum mechanical braking torque of the mechanical brake; k1 is a first preset coefficient greater than 0, and k2 is a second preset coefficient greater than 0. In some implementations, k1=k2=1. Here, the first slope is -k1·T_current / t_blend, and the second slope is k2·T_mech_max / t_blend.

[0069] As one implementation method, the total braking torque is the sum of the electric braking torque and the mechanical braking torque, that is, the total braking torque T_total = T_brake_electric + T_brake_mechanical.

[0070] Thus, by controlling the electric braking torque to decrease linearly and smoothly over time, and by controlling the mechanical braking torque to increase linearly and smoothly over time, a relatively full and basically stable total braking torque can be provided, thereby making the braking process of the slewing platform smooth.

[0071] As one implementation, the second slope can be the opposite of the first slope, or in other words, the second slope and the first slope can be opposites of each other. For example, letting k1·T_current = k2·T_mech_max, then the first slope -k1·T_current / t_blend and the second slope k2·T_mech_max / t_blend can be opposites of each other. In this way, the rate of decrease of the electric braking torque can be kept consistent with the rate of increase of the mechanical braking torque, so as to provide a smoother total braking torque, thereby enabling a smoother braking process for the slewing platform.

[0072] In some embodiments, when the first moment of inertia of the rotary platform is greater than or equal to a preset moment of inertia threshold, the absolute value of the first slope is the first slope value, and the second slope is the second slope value; when the first moment of inertia is less than the preset moment of inertia threshold, the absolute value of the first slope is the third slope value, and the second slope is the fourth slope value, wherein the third slope value is greater than the first slope value, and the fourth slope value is greater than the second slope value. For example, when the first moment of inertia of the rotary platform is greater than or equal to the preset moment of inertia threshold, the absolute value of the first slope and the second slope may be less than or equal to the preset slope threshold, while when the first moment of inertia of the rotary platform is less than the preset moment of inertia threshold, the absolute value of the first slope and the second slope may be greater than the preset slope threshold.

[0073] In the above embodiments, with a large moment of inertia, a slower rate of decrease in electric braking torque and a slower rate of increase in mechanical braking torque can be used to improve the smoothness of the transition from electric braking to mechanical braking. With a small moment of inertia, a faster rate of decrease in electric braking torque and a faster rate of increase in mechanical braking torque can be used to achieve a faster transition from electric braking to mechanical braking. This allows for adjustment of the slope according to the magnitude of the moment of inertia to adapt to different load conditions, effectively optimizing the switching impact and preventing sudden torque changes between electric braking and mechanical braking, thus ensuring a smooth and efficient transition from electric braking to mechanical braking.

[0074] It should be understood that the first slope is variable, for example, it is the first value in the first time period and the second value in the second time period; the second slope is also variable, for example, it is the third value opposite to the first value in the first time period and the fourth value opposite to the second value in the second time period.

[0075] As one implementation, the electric braking torque can be controlled to decrease linearly over time based on a corresponding first slope by a current loop control unit. As another implementation, the mechanical braking torque can be controlled to increase over time based on a corresponding second slope by controlling the mechanical brake.

[0076] The following combination Figure 2 Describe some embodiments of coordinated braking using electric and mechanical braking.

[0077] In step S210, the slewing platform is braked based on the feedforward braking torque.

[0078] In step S220, the current electric braking torque and the current rotational speed of the slewing platform are monitored. As some embodiments, the current rotational speed of the slewing platform can be monitored by a speed loop control unit. As some embodiments, the current electric braking torque can be detected by a current loop control unit.

[0079] In step S230, it is determined whether the current rotation speed of the rotary platform is less than or equal to the first rotation speed threshold. If yes, step S240 is executed; otherwise, step S210 is returned to be executed.

[0080] In step S240, it is determined whether the current electric braking torque is less than or equal to the torque threshold. If yes, step S250 is executed; otherwise, step S260 is executed.

[0081] In step S250, the mechanical brake is engaged. Here, after the mechanical brake is engaged, the process transitions from electric braking to mechanical braking, and then proceeds to a combined electric and mechanical braking phase.

[0082] In step S260, the electric braking torque is allowed to decrease. As one implementation, the electric braking torque can be reduced via a current loop control unit. After executing step S260, step S220 can be executed.

[0083] In step S270, the electric braking torque is controlled to decrease linearly, while the mechanical braking torque is controlled to increase linearly. This allows for a smooth transition from electric braking to mechanical braking, enabling the slewing platform to brake smoothly under the combined action of the electric and mechanical braking torques.

[0084] In some embodiments, the target braking position and the current position of the slewing platform can be represented by an angle (such as an angle relative to a reference position). As some implementations, the error between the target braking position and the current position of the slewing platform can be expressed as:

[0085] e_θ = θ_target - θ_current, where e_θ represents the error between the target braking position and the current position of the slewing platform; θ_target represents the target braking position; and θ_current represents the current position of the slewing platform.

[0086] In some embodiments, the target braking position can be obtained based on the following formula:

[0087] θ_target = θ_brake_start + θ_correction, where θ_target represents the target braking position; θ_brake_start is the position of the slewing platform when braking begins; and θ_correction represents the position correction amount. As some implementations, the position correction amount can be obtained, for example, based on the predicted stopping error, to compensate for the prediction error.

[0088] In some embodiments, the target electric braking torque can be obtained based on the error between the target braking position and the current position of the slewing platform. In some embodiments, the position loop control unit can obtain the target electric braking torque of the motor based on the error between the target braking position and the current position of the slewing platform.

[0089] In some embodiments, the target electric braking torque can be obtained based on the error between the target braking position and the current position of the slewing platform and closed-loop control parameters. Here, the closed-loop control parameters may include at least one of proportional gain, derivative gain, and integral gain. For example, the closed-loop control parameters may include any one of proportional gain, derivative gain, and integral gain; or, for another example, the closed-loop control parameters may include any two of proportional gain, derivative gain, and integral gain; or, for yet another example, the closed-loop control parameters may include all three of proportional gain, derivative gain, and integral gain.

[0090] In some embodiments, the target electric braking torque can be obtained based on the following formula:

[0091] T_brake_fine = Kp·(e_θ) + Kd·(de_θ / dt) + Ki·(∫e_θdt), where T_brake_fine represents the target electric braking torque; Kp represents the proportional gain; Kd represents the differential gain; Ki represents the integral gain; de_θ / dt represents the derivative of the error e_θ with respect to time; and ∫e_θdt represents the integral of the error with respect to time.

[0092] As one implementation method, the position loop control unit can obtain the target electric braking torque based on the error between the target braking position and the current position of the slewing platform, and the closed-loop control parameters of the position loop control unit. Specifically, the position loop control unit can obtain the target electric braking torque based on the above formula, and then input the target electric braking torque to the current loop control unit to control the motor to brake the slewing platform based on the target electric braking torque.

[0093] In some embodiments, when the absolute value of the error between the target braking position and the current position of the slewing platform is less than or equal to a first position error threshold and greater than a second position error threshold, and the rotational speed of the slewing platform is less than or equal to a second rotational speed threshold, a corresponding target electric braking torque can be obtained by applying closed-loop control parameters of appropriate magnitude based on the magnitude of the error, thereby more precisely adjusting the electric braking torque. As some implementations, the closer the current position of the slewing platform is to the target braking position, the smaller the value of at least one parameter in the closed-loop control parameters can be. For example, the closer the current position of the slewing platform is to the target braking position, the smaller the values ​​of any one, any two, or all three parameters of the proportional gain, derivative gain, and integral gain can be.

[0094] In some implementations, in response to the absolute value of the error between the target braking position and the current position of the slewing platform being less than or equal to a first position error threshold and greater than a second position error threshold, if the absolute value of the error between the target braking position and the current position of the slewing platform is greater than the first threshold, the target electric braking torque can be obtained based on the error between the target braking position and the current position of the slewing platform and a first closed-loop control parameter; if the absolute value of the error between the target braking position and the current position of the slewing platform is greater than the second threshold and less than or equal to the first threshold, the target electric braking torque can be obtained based on the error between the target braking position and the current position of the slewing platform and a second closed-loop control parameter; if the absolute value of the error between the target braking position and the current position of the slewing platform is less than or equal to the second threshold, the target electric braking torque can be obtained based on the error between the target braking position and the current position of the slewing platform and a third closed-loop control parameter. Here, the first threshold is greater than the second threshold and can be less than the first position error threshold. The second threshold can be greater than the second position error threshold. In some implementations, the first threshold can be 10 degrees. In some implementations, the second threshold can be 2 degrees.

[0095] Here, the value of at least one parameter in the second closed-loop control parameters is smaller than the value of the corresponding at least one parameter in the first closed-loop control parameters, and the value of at least one parameter in the third closed-loop control parameters is smaller than the value of the corresponding at least one parameter in the second closed-loop control parameters. For example, if the first, second, and third closed-loop control parameters all include corresponding proportional gains, then the value of the proportional gain in the second closed-loop control parameters can be smaller than the value of the proportional gain in the first closed-loop control parameters, and the value of the proportional gain in the third closed-loop control parameters can be smaller than the value of the proportional gain in the second closed-loop control parameters. For example, if the first, second, and third closed-loop control parameters each include a proportional gain, derivative gain, and integral gain, then in the second closed-loop control parameter, the value of the proportional gain can be smaller than the value of the proportional gain in the first closed-loop control parameter, and / or the value of the derivative gain can be smaller than the value of the derivative gain in the first closed-loop control parameter, and / or the value of the integral gain can be smaller than the value of the integral gain in the first closed-loop control parameter; in the third closed-loop control parameter, the value of the proportional gain can be smaller than the value of the proportional gain in the second closed-loop control parameter, and / or the value of the derivative gain can be smaller than the value of the derivative gain in the second closed-loop control parameter, and / or the value of the integral gain can be smaller than the value of the integral gain in the second closed-loop control parameter.

[0096] In the above embodiments, the target electric braking torque is obtained according to the magnitude of the absolute value of the error, so as to finely adjust the braking torque, prevent overshoot, and help improve braking efficiency while making the slewing platform smoothly approach the target braking position.

[0097] In some embodiments, controlling the motor to brake the slewing platform based on the target electric braking torque includes: causing the current loop control unit to adjust the current of the motor based on the target electric braking torque so that the motor generates a second electric braking torque corresponding to the target electric braking torque, so that the motor controls the slewing platform to brake based on the second electric braking torque.

[0098] As one implementation method, the current loop control unit can obtain the second electric braking torque based on the error between the target electric braking torque and the current electric braking torque, and the closed-loop control parameters of the current loop control unit (e.g., at least one of proportional gain, derivative gain, and integral gain). Thus, the current loop control unit can generate the corresponding second electric braking torque with relatively high precision based on the target electric braking torque.

[0099] In some embodiments, in response to the absolute value of the error between the target braking position and the current position of the rotary platform being less than or equal to a second position error threshold, the motor is also controlled to disengage from braking the rotary platform. As some implementations, the motor can be prevented from generating electric braking torque, or its electric braking torque can be set to zero, for example, via a current loop control unit. This ensures that the rotary platform stops more smoothly and reliably when the mechanical brake is engaged.

[0100] The following combination Figure 3 Some embodiments are described to achieve precise positioning by finely adjusting the electric braking torque through error.

[0101] In step S310, the error between the target braking position and the current position of the slewing platform is calculated.

[0102] In step S320, it is determined whether the absolute value of the error between the target braking position and the current position of the slewing platform is less than or equal to the second position error threshold. If yes, step S360 is executed; otherwise, step S330 is executed.

[0103] In step S330, the closed-loop control parameters of the position loop control unit are determined based on the magnitude of the absolute value of the error. As some embodiments, in response to the absolute value of the error between the target braking position and the current position of the slewing platform being greater than a first threshold, the closed-loop control parameters of the position loop control unit are determined as first closed-loop control parameters. In response to the absolute value of the error between the target braking position and the current position of the slewing platform being greater than a second threshold and less than or equal to the first threshold, the closed-loop control parameters of the position loop control unit are determined as second closed-loop control parameters. In response to the absolute value of the error between the target braking position and the current position of the slewing platform being less than or equal to the second threshold, the closed-loop control parameters of the position loop control unit are determined as third closed-loop control parameters.

[0104] In step S340, the target electric braking torque is obtained based on the error between the target braking position and the current position of the slewing platform and the closed-loop control parameters of the position loop control unit. As some embodiments, the target electric braking torque can be obtained, for example, by sending a corresponding instruction to the position loop control unit, causing the position loop control unit to obtain the target electric braking torque based on the error between the target braking position and the current position of the slewing platform and the closed-loop control parameters of the position loop control unit.

[0105] In step S350, the slewing platform is braked based on the target electric braking torque. After executing step S350, the process can return to step S310. As some implementations, the target electric braking torque, obtained by the position loop control unit based on the error between the target braking position and the current position of the slewing platform, and the closed-loop control parameters of the position loop control unit, can be used to control the motor to brake the slewing platform based on the target electric braking torque.

[0106] In step S360, a command instructing the mechanical brake to lock is issued. As some embodiments, in response to receiving the command instructing the mechanical brake to lock from the position ring control unit, the mechanical brake can be controlled to lock, thereby stopping the rotary platform.

[0107] In this way, the target electric braking torque can be obtained, so as to achieve fine adjustment of the torque, thereby achieving precise positioning and stopping the rotary platform at the desired position.

[0108] The following combination Figure 4 Some embodiments of the slewing control method according to this disclosure are described.

[0109] In step S401, the slewing brake command is triggered.

[0110] In step S402, the feedforward braking torque is calculated.

[0111] In step S403, the rotary platform is braked based on the feedforward braking torque.

[0112] In step S404, the rotational speed of the slewing platform is monitored. Here, the braking and deceleration process of the slewing platform can be monitored by the speed loop control unit to ensure that the actual deceleration is close to the target. When the deceleration is too fast, the output of the current loop control unit is limited to prevent over-braking.

[0113] In step S405, it is determined whether the first condition is met. If yes, step S406 is executed; otherwise, the process returns to step S404. Here, the first condition is that the rotational speed of the slewing platform is less than or equal to a first speed threshold and the current electric braking torque of the motor is less than or equal to a torque threshold. As some implementations, if the rotational speed of the slewing platform is greater than the first speed threshold, before returning to step S404, the slewing platform can continue to be braked based on the previously calculated feedforward braking torque. Alternatively, the feedforward braking torque can be recalculated to adapt to the change in rotational inertia caused by attitude changes during the slewing process, and then the slewing platform can be braked based on the recalculated feedforward braking torque. As some implementations, if the current electric braking torque is greater than the torque threshold, before returning to step S404, the electric braking torque can be controlled to decrease until the current electric braking torque is less than or equal to the torque threshold by the current loop control unit.

[0114] In step S406, the electric braking torque is controlled to decrease linearly and the mechanical braking torque to increase linearly. Here, the electric braking torque can be controlled to decrease linearly through a current loop control unit; the mechanical brake can be controlled to engage linearly so that the mechanical braking torque increases linearly.

[0115] In step S407, the total braking torque is maintained continuously. Here, the slewing platform can be braked based on the total braking torque. As some embodiments, the total braking torque can be the sum of the electric braking torque and the mechanical braking torque.

[0116] In step S408, it is determined whether the second condition is met. If yes, step S409 is executed; otherwise, step S407 is executed. Here, the second condition is that the absolute value of the error between the target braking position and the current position of the slewing platform is less than or equal to the first position error threshold and greater than the second position error threshold, and the rotational speed of the slewing platform is less than or equal to the second rotational speed threshold.

[0117] In step S409, the target electric braking torque is calculated based on the error.

[0118] In step S410, the slewing platform is braked based on the target electric braking torque.

[0119] In step S411, it is determined whether the absolute value of the error between the target braking position and the current position of the slewing platform is less than or equal to the second position error threshold. If yes, step S412 is executed; otherwise, the process returns to step S410. Here, if the process returns to step S410, the slewing platform can continue to be braked based on the previously calculated target electric braking torque, or the target electric braking torque can be recalculated to adapt to the change in the current position, and then the slewing platform can be braked based on the recalculated target electric braking torque.

[0120] In step S412, the mechanical brake is locked. Here, the mechanical brake can be kept locked to ensure that the rotary platform stops smoothly and accurately.

[0121] In some embodiments, a predictive control algorithm can be used to optimize the braking trajectory and calculate a torque sequence based on the optimized braking trajectory so as to brake the slewing platform based on the corresponding torque sequence.

[0122] In some embodiments, a target braking curve can be selected from a curve library containing multiple preset braking curves according to the working conditions of the engineering machinery, and the slewing platform can be braked based on the target braking curve.

[0123] In some embodiments, during the initial braking phase of the slewing platform (such as within a preset time period after receiving a slewing braking command), the current loop control unit calculates the corresponding electric braking torque based on phase advance compensation to improve the response speed.

[0124] Figure 5 A schematic diagram illustrating a variation in electric braking torque and mechanical braking torque is shown.

[0125] like Figure 5 As shown, in Phase 1 (0~200ms), in response to the turn braking command, the electric braking torque rapidly rises to its peak value based on the calculated feedforward braking torque. Here, in Phase 1, the electric braking system can undertake all braking tasks.

[0126] In phase two (200~500ms), electric braking and mechanical braking work together intelligently. Here, electric braking weakens while mechanical braking strengthens; that is, the electric braking torque decreases linearly with time, while the mechanical braking torque increases linearly with time, and the total braking torque remains continuous and full.

[0127] In phase three (500~600ms), the electric brake disengages, while the mechanical brake remains locked.

[0128] It should be understood that Figure 5 The diagram only schematically illustrates a general trend in the variation of electric braking torque and mechanical braking torque, for example... Figure 5 It is shown that in Phase 2, the first slope of the decrease in electric braking torque and the second slope of the increase in mechanical braking torque are adjusted only once. However, in some cases, in Phase 2, the first slope of the decrease in electric braking torque and the second slope of the increase in mechanical braking torque may not be adjusted or may be adjusted more than once.

[0129] Alternatively, in some cases, during stage two, if the electric braking torque decreases linearly with time while the mechanical braking torque increases linearly with time, and the second condition is met (i.e., the absolute value of the error between the target braking position and the current position of the slewing platform is less than or equal to the first position error threshold and greater than the second position error threshold, and the rotational speed of the slewing platform is less than or equal to the second rotational speed threshold), then the mechanical braking torque can be maintained at the current mechanical braking torque. Then, the target braking torque is calculated based on the error between the target braking position and the current position of the slewing platform to adjust the electric braking torque. That is, in this case, if the second condition is met, the mechanical braking torque may be less than... Figure 5 The figure shown represents the mechanical braking torque that increases over time to the maximum, but it is not the current mechanical braking torque that remains when the second condition is met. The electric braking torque may be less than... Figure 5 Instead of linearly decreasing to zero over time as shown, the electric braking torque is finely adjusted based on the corresponding position error when the second condition is met, until the error between the target braking position and the current position of the slewing platform is less than or equal to the second position error threshold, and then enters stage three, exits electric braking, and controls the mechanical brake to lock.

[0130] Alternatively, in some cases, during stage two, the electric braking torque decreases to zero over time, while the mechanical braking torque increases to its maximum. If, at this point, the error between the target braking position and the current position of the slewing platform is still greater than the first position error threshold or the slewing platform's rotational speed is still greater than the second rotational speed threshold, then braking of the slewing platform based on the maximum mechanical braking torque can be maintained until the second condition is met (i.e., the absolute value of the error between the target braking position and the current position of the slewing platform is less than or equal to the first position error threshold and greater than the second position error threshold, and the slewing platform's rotational speed is less than or equal to the second rotational speed threshold). Then, the mechanical braking torque is maintained at its maximum, and the electric braking torque is finely adjusted based on the current error until the error between the target braking position and the current position of the slewing platform is reached. Stage three then begins, the electric braking is disengaged, and the mechanical brake is kept locked.

[0131] Embodiments of this disclosure also provide a slewing control device that can be configured to execute the slewing control method of any of the above embodiments.

[0132] In some embodiments, the slewing control device may include a module for performing the slewing control method of any of the above embodiments.

[0133] Figure 6 A schematic diagram of a slewing control device according to some embodiments of the present disclosure is shown. For example... Figure 6As shown, the slewing control device 600 may include a first braking module 610, a first control module 620, a second braking module 630, and a second control module 640.

[0134] The first braking module 610 can be configured to control a motor connected to the slewing platform to brake the slewing platform in response to a slewing braking command indicating a target braking position.

[0135] The first control module 620 can be configured to control the electric braking torque of the motor to decrease from the current electric braking torque over time and control the mechanical braking torque of the mechanical brake connected to the rotary platform to increase over time in response to the rotational speed of the rotary platform being less than or equal to a first speed threshold and the current electric braking torque of the motor being less than or equal to a torque threshold.

[0136] The second braking module 630 can be configured to control the motor to brake the slewing platform based on a target electric braking torque in response to the absolute value of the error between the target braking position and the current position of the slewing platform being less than or equal to a first position error threshold and greater than a second position error threshold, and the rotational speed of the slewing platform being less than or equal to a second rotational speed threshold. The target electric braking torque is obtained based on the error between the target braking position and the current position of the slewing platform, the second rotational speed threshold is less than the first rotational speed threshold, and the second position error threshold is less than the first position error threshold.

[0137] The second control module 640 can be configured to control the mechanical brake to perform a locking operation in response to the absolute value of the error being less than or equal to a second position error threshold, so as to stop the rotary platform from moving.

[0138] In some embodiments, the slewing control device 600 may further include other modules to perform the slewing control method of any of the above embodiments.

[0139] For details on the operation of the various modules in the slewing control device 600, please refer to the detailed explanation of the slewing control method above, which will not be repeated here.

[0140] Figure 7 A schematic diagram of a slewing control device according to other embodiments of the present disclosure is shown. For example... Figure 7 As shown, the slewing control device 700 may include a memory 710 and a processor 720 coupled to the memory 710. The processor 720 may be configured to execute the slewing control method of any of the foregoing embodiments based on instructions stored in the memory 710.

[0141] Specifically, processor 720 can perform various actions and processes according to instructions stored in memory 710. Processor 720 can be an integrated circuit chip with signal processing capabilities. The processor can be a general-purpose processor, digital signal processor (DSP), application-specific integrated circuit (ASIC), field-programmable gate array (FPGA), or other programmable logic device, discrete gate or transistor logic device, or discrete hardware component. It can implement or execute the various methods, steps, and logic block diagrams disclosed in the embodiments of this disclosure. The general-purpose processor can be a microprocessor or any conventional processor, and can be an x86 architecture or an ARM architecture, etc.

[0142] Memory 710 stores executable instructions that, when executed by processor 720, implement the spin control method described above. Memory 710 may be volatile memory or non-volatile memory, or may include both. Non-volatile memory may be read-only memory (ROM), programmable read-only memory (PROM), erasable programmable read-only memory (EPROM), electrically erasable programmable read-only memory (EEPROM), or flash memory. Volatile memory may be random access memory (RAM), which serves as an external cache. By way of example, but not limitation, many forms of RAM are available, such as static random access memory (SRAM), dynamic random access memory (DRAM), synchronous dynamic random access memory (SDRAM), double data rate synchronous dynamic random access memory (DDRSDRAM), enhanced synchronous dynamic random access memory (ESDRAM), synchronous linked dynamic random access memory (SLDRAM), and direct memory bus random access memory (DR RAM). It should be noted that the memory of the methods described herein is intended to include, but is not limited to, these and any other suitable types of memory.

[0143] The following combination Figure 8 Some embodiments of a slewing control system for construction machinery according to this disclosure are described.

[0144] like Figure 8 As shown, the slewing control system 800 may include a sensing layer 810, a control layer 820, an execution layer 830, and a load layer 840.

[0145] The sensing layer 810 may include a platform position encoder 811, a platform tilt sensor 812, a motor speed encoder 813, a joint angle sensor 814, a load weight sensor 815, and a control handle 816. The motor speed encoder 813 is mounted on the motor shaft of the motor 834 and is used to provide feedback on the rotational speed of the motor 834; the platform position encoder 811 is mounted on the slewing platform 841 and provides feedback on the angular position of the slewing platform 841; the control handle 816 is located in the cab and serves as an input signal to control the slewing braking of the slewing platform 841. Joint angle sensor 814 is installed at the joints of boom, stick, and bucket to provide feedback on the attitude of working device 842; load weight sensor 815 is installed on the bucket to provide feedback on the weight of the load inside the bucket; platform tilt sensor 812 is installed on the slewing platform 841 on the upper vehicle to provide feedback on the tilt angle of the slewing platform 841; the total load torque required for slewing braking of the slewing platform 841 can be determined by the joint angle sensor 814, load weight sensor 815, and platform tilt sensor 812.

[0146] The control layer 820 may include a main controller 811 and a three-level control loop unit 822. The main controller 821 can be used to control the three-level control loop unit 822 and also to control the mechanical brake 832 to achieve mechanical braking. The main controller 821 can be configured to execute the slewing control method of any of the above embodiments. In some embodiments, the main controller 821 may include a slewing control device of any of the above embodiments (e.g., slewing control device 600, slewing control device 700). The three-level control loop unit 822 includes a position loop control unit 8221, a speed loop control unit 8222, and a current loop control unit 8223.

[0147] The position loop control unit 8221 can be configured to calculate the target rotational speed based on the position error between the current position and the target position of the rotary platform 841. When the position error is large, the target rotational speed is large; when the position error is small, the target rotational speed is small to slowly approach the target position and prevent out-of-range errors. The speed loop control unit 8222 is used to control the rotational speed of the rotary platform. The speed loop control unit can be configured to calculate the target torque (or target current) based on the speed error between the current rotational speed and the target rotational speed of the rotary platform 841. When the speed error is large, the target torque is large; when the speed error is small, the target torque is small. Specifically, when the current rotational speed is slow, it can instruct an increase in torque for acceleration; when the current rotational speed is fast, it can instruct a decrease in torque or apply reverse torque for deceleration. The current loop control unit 8223 is used to precisely control the output torque of the motor. Through high-frequency and rapid adjustment, it can change the output voltage and frequency of the motor driver 833 to ensure that the actual current follows the target current.

[0148] The execution layer 830 may include a speed reducer 831, a mechanical brake 832, a motor driver 833, and a motor 834. The motor driver 833 is used to control the motor 834. The motor 834 is connected to the speed reducer 831 and is mounted on the rotary platform 841. The mechanical brake 832 (a controllable braking system) is connected to the speed reducer 831 and is used to achieve mechanical braking.

[0149] The load layer 840 may include a slewing platform 841 and a working device 842 of the construction machinery. The working device may include a boom, stick, and bucket, and the working device 842 is mounted on the slewing platform 841.

[0150] In some embodiments, the main controller 821 can calculate a feedforward braking torque to brake the slewing platform based on the feedforward braking torque.

[0151] In some embodiments, the feedforward braking torque can be obtained based on the total load torque of the slewing platform. Specifically, T_load = T_inertia + T_gravity, where T_load is the total load torque of the slewing platform, representing the total resistance torque that the motor needs to overcome; T_inertia is the inertial torque, representing the torque required to overcome the rotational inertia of the system; and T_gravity is the gravitational torque, representing the torque required to overcome the gravitational component on the ramp. In some implementations, T_inertia = J_total·α_current, where J_total is the first moment of inertia of the slewing platform, representing the total moment of inertia referred to the motor shaft, and α_current is the current angular acceleration (negative during deceleration); T_gravity = (m+m0)·g·R·sin(θ+φ), where m is the total mass of the upper slewing platform (excluding the material in the bucket), m0 is the weight of the load in the bucket, g is the gravitational acceleration (approximately 9.8 m / s²), R is the horizontal distance from the system's center of mass to the center of rotation (varying with the attitude of the working device), θ is the angle of the slewing platform relative to the reference position; and φ is the ramp angle, representing the tilt angle of the slewing platform relative to the horizontal plane. In some implementations, the first moment of inertia of the slewing platform J_total = J_motor + J_reduction + J_load(θ_boom,θ_arm,θ_bucket,m0) / i 2Where J_motor is the second moment of inertia of the motor rotor; J_reduction is the third moment of inertia of the reducer; i is the reduction ratio of the reducer; J_load is the fourth moment of inertia of the load (which varies with the attitude of the working device); J_load(θ_boom,θ_arm,θ_bucket,m0) means that J_load is obtained based on θ_boom, θ_arm, θ_bucket, and m0, where θ_boom is the boom joint angle, θ_arm is the stick joint angle, θ_bucket is the bucket joint angle, and m0 is the load weight in the bucket.

[0152] In other embodiments, the feedforward braking torque can be obtained based on a preset angular deceleration and the first moment of inertia of the rotating platform. The relevant description can be found above and will not be repeated here.

[0153] Embodiments of this disclosure also provide a construction machinery. In some embodiments, the construction machinery may include a slewing control device (slewing control device 600 or slewing control device 700 as described above) of any of the above embodiments. In some embodiments, the construction machinery may include a slewing control system 800 of any of the above embodiments. In some embodiments, the construction machinery may include an excavator.

[0154] This disclosure also proposes a non-transitory computer-readable storage medium storing a computer program that, when executed by a processor, can implement the steps of the rotation control method described above.

[0155] Similarly, the non-transitory computer-readable storage media in the embodiments of this disclosure are intended to include, but are not limited to, the above and any other suitable types of memory.

[0156] This disclosure also proposes a computer program product that may include a computer program that, when executed by a processor, can implement the steps of the rotary control method as described above.

[0157] Instructions can be any set of instructions that will be executed directly by one or more processors, such as machine code, or any set of instructions that will be executed indirectly, such as a script. The terms “instruction,” “application,” “procedure,” “step,” “program,” and “computer program” used herein are used interchangeably. Instructions can be stored in object code format for direct processing by one or more processors, or stored in any other computer language, including scripts or sets of independent source code modules that are interpreted on demand or compiled in advance. The function, methods, and routines of instructions are explained in more detail in other parts of this document.

[0158] Figure 9A schematic block diagram of a computer system 900 on which embodiments of the present disclosure may be implemented is shown. The computer system 900 includes a bus 910 or other communication mechanism for transmitting information, and a processing means 920 coupled to the bus 910 for processing information. The computer system 900 also includes a memory coupled to the bus 910 for storing instructions to be executed by the processing means 920; the memory may be random access memory (RAM) or other dynamic storage device. The memory (such as RAM 930) may also be used to store temporary variables or other intermediate information during the execution of instructions to be executed by the processing means 920. The computer system 900 may also include a read-only memory (ROM 940) or other static storage device coupled to the bus 910 for storing static information and instructions for the processing means 920. A storage device 950, such as a magnetic disk or optical disk, is provided and coupled to the bus 910 for storing information and instructions. Computer system 900 may be coupled via bus 910 to output device 960 for providing output to a user, such as, but not limited to, a display (such as a cathode ray tube (CRT) or liquid crystal display (LCD)), speakers, etc. Input device 970, such as a keyboard, mouse, microphone, etc., is coupled to bus 910 for transmitting information and command selection to processing device 920. Computer system 900 may execute embodiments of the present disclosure. Consistent with certain implementations of the present disclosure, computer system 900 provides results by executing one or more sequences of one or more instructions contained in memory (such as RAM 930) in response to processing device 920. Such instructions may be read into memory (such as RAM 930) from another computer-readable medium, such as storage device 950. Execution of the sequence of instructions contained in memory (such as RAM 930) causes processing device 920 to perform the methods described herein. Alternatively, the teachings may be implemented using hard-wired circuitry in place of or in combination with software instructions. Therefore, implementations of the present disclosure are not limited to any particular combination of hardware circuitry and software. In various embodiments, computer system 900 can be connected across a network via network interface 980 to one or more other computer systems, such as computer system 900, to form a networked system. This network may include a private network or a public network such as the Internet. In a networked system, one or more computer systems can store data and supply data to other computer systems. As used herein, the term "computer-readable medium" refers to any medium that participates in providing instructions to processing device 920 for execution. Such media can take many forms, including but not limited to non-volatile media, volatile media, and transmission media. Non-volatile media include, for example, optical discs or magnetic disks such as storage device 950. Volatile media include dynamic memory such as memory (e.g., RAM 930).Transmission media include coaxial cable, copper wire, and optical fiber, including cabling containing bus 910. Common forms of computer-readable media or computer program products include, for example, floppy disks, flexible disks, hard disks, magnetic tape, or any other magnetic media, CD-ROMs, digital video discs (DVDs), Blu-ray discs, any other optical media, thumb drives, memory cards, RAM, PROMs and EPROMs, fast EPROMs, any other memory chips or cartridges, or any other tangible media from which a computer can read. Various forms of computer-readable media may be involved when carrying one or more sequences of one or more instructions to processing device 920 for execution. For example, instructions may initially be carried on a disk of a remote computer. The remote computer may load the instructions into its dynamic memory and transmit the instructions over a telephone line using a modem. A modem local to computer system 900 may receive data over the telephone line and convert the data into an infrared signal using an infrared transmitter. An infrared detector coupled to bus 910 may receive the data carried in the infrared signal and place the data on bus 910. Bus 910 carries data to memory (such as RAM 930), and processing device 920 retrieves instructions from memory (such as RAM 930) and executes the instructions. Optionally, instructions received from memory (such as RAM 930) may be stored on storage device 950 before or after execution by processing device 920.

[0159] According to various embodiments, instructions configured to be executed by processing device 920 to perform a method are stored on a computer-readable medium. The computer-readable medium may be a device for storing digital information. For example, the computer-readable medium includes a compact disc read-only memory (CD-ROM) as known in the art for storing software. The computer-readable medium is accessed by a processor adapted to execute the instructions configured to be executed.

[0160] It should be noted that the flowcharts and block diagrams in the accompanying drawings illustrate the architecture, functionality, and operation of possible implementations of systems, methods, and computer program products according to various embodiments of this disclosure. 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 indicated in the blocks may occur in a different order than those indicated in the drawings. For example, two consecutively indicated 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 the block diagrams and / or flowcharts, and combinations of blocks in the block diagrams and / or flowcharts, can be implemented using a dedicated hardware-based system that performs the specified function or operation, or using a combination of dedicated hardware and computer instructions.

[0161] In general, the various exemplary embodiments of this disclosure can be implemented in hardware or dedicated circuitry, software, firmware, logic, or any combination thereof. Some aspects can be implemented in hardware, while others can be implemented in firmware or software that can be executed by a controller, microprocessor, or other computing device. When aspects of embodiments of this disclosure are illustrated or described as block diagrams, flowcharts, or using some other graphical representation, it will be understood that the blocks, apparatuses, systems, techniques, or methods described herein can be implemented as non-limiting examples in hardware, software, firmware, dedicated circuitry or logic, general-purpose hardware or controllers or other computing devices, or some combination thereof.

[0162] As used herein, the term “exemplary” means “used as an example, instance, or illustration” and not as a “model” to be exactly copied. Any implementation described herein by example is not necessarily to be construed as preferred or advantageous over other implementations.

[0163] Furthermore, terms such as “first,” “second,” etc., may be used in this document for reference purposes only and are not intended to be limiting. For example, unless the context clearly indicates otherwise, the words “first,” “second,” and other such numerical terms relating to structures or elements do not imply order or sequence.

[0164] It should also be understood that when the term “including / contains” is used herein, it indicates the presence of the indicated feature, whole, step, operation, unit and / or component, but does not preclude the presence or addition of one or more other features, wholes, steps, operations, units and / or components and / or combinations thereof.

[0165] In this disclosure, the term “provide” is used broadly to cover all ways of obtaining an object, and therefore “provide an object” includes, but is not limited to, “purchasing,” “preparing / manufacturing,” “arranging / setting up,” “installing / assembling,” and / or “ordering” an object.

[0166] As used herein, the term “and / or” includes any and all combinations of one or more of the listed items in association. The terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of this disclosure. As used herein, the singular forms “a,” “an,” and “the” are also intended to include the plural forms unless the context clearly indicates otherwise.

[0167] Those skilled in the art will recognize that the boundaries between the above operations are merely illustrative. Multiple operations may be combined into a single operation, a single operation may be distributed among additional operations, and operations may be performed with at least partial overlap in time. Moreover, alternative embodiments may include multiple instances of a particular operation, and the order of operations may be changed in various other embodiments. However, other modifications, variations, and substitutions are equally possible. Aspects and elements of all the embodiments disclosed above may be combined in any way and / or in combination with aspects or elements of other embodiments to provide multiple additional embodiments. Therefore, this specification and the accompanying drawings should be considered illustrative rather than restrictive.

[0168] While specific embodiments of this disclosure have been described in detail by way of example, those skilled in the art should understand that the examples are for illustrative purposes only and not intended to limit the scope of this disclosure. The various embodiments disclosed herein can be combined in any way without departing from the spirit and scope of this disclosure. Those skilled in the art should also understand that various modifications can be made to the embodiments without departing from the scope and spirit of this disclosure. The scope of this disclosure is defined by the appended claims.

Claims

1. A slewing control method, comprising: In response to a slewing braking command indicating a target braking position, the motor connected to the slewing platform is controlled to brake the slewing platform; In response to the rotational speed of the rotary platform being less than or equal to a first rotational speed threshold and the current electric braking torque of the motor being less than or equal to a torque threshold, the electric braking torque of the motor is controlled to decrease from the current electric braking torque over time, and the mechanical braking torque of the mechanical brake connected to the rotary platform is controlled to increase over time. In response to the absolute value of the error between the target braking position and the current position of the slewing platform being less than or equal to a first position error threshold and greater than a second position error threshold, and the rotational speed of the slewing platform being less than or equal to a second rotational speed threshold, the motor is controlled to brake the slewing platform based on the target electric braking torque, wherein the target electric braking torque is obtained based on the error, the second rotational speed threshold is less than the first rotational speed threshold, and the second position error threshold is less than the first position error threshold; as well as In response to the absolute value of the error being less than or equal to the second position error threshold, the mechanical brake is controlled to perform a locking operation to stop the rotary platform from moving.

2. The slewing control method according to claim 1, wherein: The electric braking torque of the motor decreases linearly over time from the current electric braking torque based on a first slope, where the first slope is negative; and The mechanical braking torque of the mechanical brake increases linearly with time based on a second slope, wherein the second slope is a positive number.

3. The slewing control method according to claim 2, wherein, The first slope and the second slope are opposite numbers.

4. The slewing control method according to claim 2, wherein: When the first moment of inertia of the rotary platform is greater than or equal to a preset moment of inertia threshold, the absolute value of the first slope is the first slope value, and the second slope is the second slope value. as well as When the first moment of inertia is less than the preset moment of inertia threshold, the absolute value of the first slope is the third slope value, and the second slope is the fourth slope value, wherein the third slope value is greater than the first slope value, and the fourth slope value is greater than the second slope value.

5. The slewing control method according to claim 1 further includes: In response to the absolute value of the error between the target braking position and the current position of the slewing platform being less than or equal to a first position error threshold and greater than a second position error threshold, and the rotational speed of the slewing platform being less than or equal to a second rotational speed threshold, the mechanical braking torque of the mechanical brake is also controlled to remain at the current mechanical braking torque.

6. The slewing control method according to claim 1, wherein, When the rotational speed of the rotary platform is greater than the first rotational speed threshold, or when the current electric braking torque of the motor is greater than the torque threshold, the mechanical braking torque of the mechanical brake is zero.

7. The slewing control method according to any one of claims 1 to 6, further comprising: In response to the rotational speed of the rotary platform being less than or equal to a first rotational speed threshold, and the current electric braking torque of the motor being greater than the torque threshold, the electric braking torque of the motor is controlled to decrease.

8. The slewing control method according to any one of claims 1 to 6, wherein, In response to a slewing braking command indicating a target braking position, controlling a motor connected to the slewing platform to brake the slewing platform includes: In response to a slewing braking command indicating a target braking position, the feedforward braking torque of the motor is obtained based on a preset angular deceleration and a first moment of inertia of the slewing platform, and the motor is controlled to brake the slewing platform based on the feedforward braking torque.

9. The slewing control method according to claim 8, wherein, The preset angular deceleration is the maximum safe angular deceleration of the rotary platform.

10. The slewing control method according to any one of claims 1 to 6, wherein: If the absolute value of the error is greater than a first threshold, the target electric braking torque is obtained based on the error and the first closed-loop control parameters; If the absolute value of the error is greater than the second threshold and less than or equal to the first threshold, the target electric braking torque is obtained based on the error and the second closed-loop control parameters. If the absolute value of the error is less than or equal to the second threshold, the target electric braking torque is obtained based on the error and the third closed-loop control parameter. Wherein, the value of at least one parameter in the second closed-loop control parameters is smaller than the value of the corresponding at least one parameter in the first closed-loop control parameters, and the value of at least one parameter in the third closed-loop control parameters is smaller than the value of the corresponding at least one parameter in the second closed-loop control parameters.

11. The slewing control method according to any one of claims 1 to 6, further comprising: In response to the absolute value of the error being less than or equal to a second position error threshold, the motor is also controlled to disengage from braking the rotary platform.

12. A slewing control device, comprising: A module configured to perform the slewing control method according to any one of claims 1 to 11.

13. A slewing control device, comprising: Memory; as well as A processor coupled to the memory is configured to execute the slewing control method according to any one of claims 1 to 11 based on instructions stored in the memory.

14. An engineering machine, comprising: The rotary control device according to claim 12 or 13.

15. A computer-readable storage medium comprising a computer program, wherein, When the computer program is executed by the processor, it implements the steps of the slewing control method according to any one of claims 1 to 11.

16. A computer program product comprising a computer program, wherein, When the computer program is executed by the processor, it implements the steps of the slewing control method according to any one of claims 1 to 11.

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