A method and device for decelerating a tower crane slewing mechanism and a medium

Abstract

The application discloses a tower crane slewing mechanism deceleration method, device and medium, and relates to the electrical control field. In order to realize smooth deceleration without replacing the torque motor, reduce the swing amplitude of the tower arm after stopping, and reduce the gear wear, the application gradually increases the deceleration acceleration in the deceleration process of the slewing mechanism. When the deceleration acceleration increases to a preset limited acceleration value, the deceleration acceleration stops increasing, and the constant acceleration is quickly decelerated. When the preset time is reached, the deceleration acceleration is gradually reduced, the acceleration is gradually reduced, and the slow deceleration releases the inertia force that has been formed and weakens the inertia force that will be generated. The acceleration does not suddenly change during the whole deceleration period, and the polishing degree of the inner and outer gears is not increased. On the basis of not increasing the cost of replacing the torque motor, the influence of the acceleration value on the tower arm slewing lag angle is maximally reduced, and the swing amplitude of the tower arm after stopping is reduced.

Description

Technical Field

[0001] This application relates to the field of electrical control, and in particular to a method, device and medium for reducing speed of a tower crane slewing mechanism. Background Technology

[0002] Tower cranes are high-inertia systems. The rigid tower jib, while rotating a load, requires smooth stopping and precise positioning. However, during deceleration, if the deceleration curve is a straight line with a constant slope (meaning the acceleration is constant throughout), the tower jib will exhibit a certain lag angle due to the support acceleration and its own inertia. When deceleration reaches zero, the slewing bearing loses braking force, and the tower jib will swing back and forth in the plane of rotation due to inertia. The magnitude of this swing is proportional to the magnitude of the angular acceleration during deceleration, and the load suspended by the jib will swing along with it. This situation is extremely dangerous in practical applications. Relying solely on friction to eliminate the sway takes a long time, and the swaying process increases the wear on the internal and external teeth of the slewing bearing, reducing its service life.

[0003] The current solutions to this type of problem are generally to use a torque motor, combined with load and eddy current control torque, to achieve smooth speed regulation; however, using a torque motor increases costs, and torque motors are prone to damage and are not easy to repair.

[0004] Therefore, it is evident that providing a method to achieve smooth deceleration without replacing the torque motor, reduce the swing amplitude of the tower arm after shutdown, and reduce gear wear is a technical problem that urgently needs to be solved by those skilled in the art. Summary of the Invention

[0005] The purpose of this application is to provide a deceleration method for the tower crane slewing mechanism, which achieves smooth deceleration without replacing the torque motor, reduces the swing amplitude of the tower arm after shutdown, and reduces gear wear.

[0006] To solve the above-mentioned technical problems, this application provides a method for reducing the speed of a tower crane slewing mechanism, comprising:

[0007] Receive shutdown command;

[0008] Control the slewing mechanism to begin deceleration, and gradually increase the deceleration acceleration;

[0009] When the deceleration increases to a preset limit value, the deceleration remains constant at the preset limit value.

[0010] When the constant deceleration reaches the preset time, the deceleration acceleration is gradually reduced until the speed of the rotary mechanism reaches the preset minimum speed value, at which point the acceleration also reaches the preset minimum acceleration.

[0011] As a preferred embodiment, the deceleration method for the tower crane slewing mechanism described above, before controlling the slewing mechanism to begin deceleration and gradually increasing the deceleration acceleration, further includes:

[0012] Get the current operating frequency, preset total downtime, preset constant deceleration frequency percentage, preset constant deceleration time percentage, preset limited acceleration value, and preset stop brake frequency;

[0013] The S-curve deceleration frequency and the composite curve deceleration frequency are obtained based on the current operating frequency and the preset constant deceleration frequency ratio.

[0014] The S-curve deceleration time and the compound curve deceleration time are obtained based on the preset total downtime and the preset constant deceleration time percentage.

[0015] As a preferred embodiment, in the deceleration method of the tower crane slewing mechanism described above, when the deceleration acceleration increases to a preset limit value, the deceleration is constant at the preset limit value, including:

[0016] The acceleration is obtained from the deceleration frequency and deceleration time of the S-curve.

[0017] The slewing mechanism is controlled by accelerometer to begin deceleration, and the deceleration is gradually increased.

[0018] When the deceleration increases to a preset limit value, the rotary mechanism is controlled to decelerate at a constant speed using the preset limit value.

[0019] As a preferred embodiment, in the deceleration method of the tower crane slewing mechanism described above, when the constant deceleration reaches a preset time, controlling the deceleration acceleration to gradually decrease includes:

[0020] Set the initial values, recursive transformation quantities, and redundancy frequencies of the preset parameters;

[0021] Based on the first function, the frequency change during the deceleration time of the composite curve is obtained;

[0022] The first function is: f(t) = LimASpeed / (1+(a*t)^2);

[0023] Where a is a preset parameter, t is the deceleration time of the compound curve, LimASpeed ​​is the preset limit acceleration value, and f(t) is the acceleration;

[0024] Determine whether the frequency change is within the error range of the compound curve deceleration frequency and the redundant frequency.

[0025] If so, then the current preset parameter is determined as the control parameter;

[0026] If not, then perform recursive calculations on the initial values ​​of the preset parameters based on the recursive transformation amount, and use the recursive result as the preset parameter. Return to the step of obtaining the frequency change amount during the deceleration time of the composite curve according to the first function, until the frequency change amount is within the error of the composite curve deceleration frequency and the redundant frequency.

[0027] The control acceleration is determined based on the control parameters and the first function;

[0028] The rotary mechanism begins to decelerate based on the controlled acceleration, where the controlled acceleration gradually decreases over time.

[0029] As a preferred embodiment, the deceleration method for the tower crane slewing mechanism described above, which involves controlling the slewing mechanism to begin deceleration based on jerk and gradually increasing the deceleration acceleration, includes:

[0030] The corresponding acceleration is obtained from the jerk.

[0031] The corresponding output frequency is obtained based on the acceleration.

[0032] The inverter output is controlled according to the output frequency to slow down the rotary mechanism;

[0033] Correspondingly, controlling the constant deceleration of the rotary mechanism with a preset limit acceleration value includes:

[0034] The corresponding output frequency is obtained based on the preset acceleration value;

[0035] The inverter output is controlled according to the output frequency to slow down the rotary mechanism;

[0036] Correspondingly, the slewing mechanism begins to decelerate according to the controlled acceleration, including:

[0037] The corresponding output frequency is obtained by controlling the acceleration.

[0038] The inverter output is controlled according to the output frequency to slow down the slewing mechanism.

[0039] As a preferred embodiment, the aforementioned deceleration method for the tower crane slewing mechanism further includes:

[0040] When the output frequency is not greater than the stop brake frequency, the inverter is stopped and a DC braking current is applied to the rotary motor.

[0041] As a preferred embodiment, in the aforementioned deceleration method for the tower crane slewing mechanism, the frequency change during the deceleration time of the composite curve is obtained according to the first function, including:

[0042] The definite integral value of the first function over the deceleration time of the compound curve is obtained from the second function;

[0043] The second function is: DalteFrq(k) = LimASpeed / a(k)*arctan(a(k)*CTime);

[0044] When k = 0, a(k) is the initial value of the preset parameter. When k > 0, a(k) is the preset parameter calculated recursively in each step. DalteFrq(k) is the frequency change and CTime is the deceleration time of the composite curve.

[0045] To solve the above-mentioned technical problems, this application also provides a speed reduction device for the slewing mechanism of a tower crane, comprising:

[0046] The receiving module is used to receive shutdown commands;

[0047] The deceleration module is used to control the rotary mechanism to start decelerating and gradually increase the deceleration acceleration;

[0048] The S-curve deceleration module is used to decelerate at a constant preset acceleration value when the deceleration acceleration increases to a preset limit value.

[0049] The compound curve deceleration module is used to control the deceleration acceleration to gradually decrease when the constant deceleration reaches a preset time, until the speed of the rotary mechanism reaches a preset minimum speed value, and the acceleration also reaches a preset minimum acceleration.

[0050] To solve the above-mentioned technical problems, this application also provides a speed reduction device for the slewing mechanism of a tower crane, comprising:

[0051] Memory, used to store computer programs;

[0052] A processor is used to execute computer programs to implement the steps of the above-described deceleration method for the tower crane slewing mechanism.

[0053] To solve the above-mentioned technical problems, this application also provides a computer-readable storage medium storing a computer program, which, when executed by a processor, implements the steps of the above-described deceleration method for the tower crane slewing mechanism.

[0054] The deceleration method for the tower crane slewing mechanism provided in this application includes: receiving a stop command; controlling the slewing mechanism to begin deceleration and gradually increasing the deceleration acceleration; when the deceleration acceleration increases to a preset limit value, maintaining a constant deceleration at the preset limit value; when the constant deceleration reaches a preset time, controlling the deceleration acceleration to gradually decrease until the speed of the slewing mechanism reaches a preset minimum speed value, at which point the acceleration also reaches the preset minimum acceleration. During the deceleration process of the slewing mechanism, the deceleration acceleration initially increases gradually. When the deceleration acceleration increases to the preset limit value, the increase in deceleration acceleration stops, and the mechanism decelerates rapidly at a constant acceleration. After reaching the preset time, the deceleration acceleration is gradually decreased. This gradual decrease in acceleration releases the existing inertial force and weakens the inertial force that will be generated. Throughout the deceleration process, there are no sudden changes in acceleration, and the grinding degree of the internal and external teeth of the support is not increased. Without increasing the cost of replacing the torque motor, the influence of the acceleration value on the slewing lag angle of the tower arm is minimized, reducing the sway amplitude of the tower arm after shutdown.

[0055] In addition, this application also provides an apparatus and a medium that correspond to the above method and have the same effect. Attached Figure Description

[0056] To more clearly illustrate the embodiments of this application, the accompanying drawings used in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0057] Figure 1 A flowchart illustrating a deceleration method for a tower crane slewing mechanism provided in an embodiment of this application;

[0058] Figure 2 A speed change diagram of a deceleration process is provided in an embodiment of this application;

[0059] Figure 3 A structural diagram of a speed reduction device for a tower crane slewing mechanism provided in an embodiment of this application;

[0060] Figure 4 A structural diagram of a speed reduction device for another tower crane slewing mechanism provided in an embodiment of this application;

[0061] Among them, curve 21 represents the velocity change curve, curve 22 represents the jerk change curve, and curve 23 represents the acceleration change curve. Detailed Implementation

[0062] The technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, and not all embodiments. Based on the embodiments of this application, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the protection scope of this application.

[0063] The core of this application is to provide a method, device, and medium for reducing the speed of a tower crane slewing mechanism.

[0064] To enable those skilled in the art to better understand the present application, the present application will be further described in detail below with reference to the accompanying drawings and specific embodiments.

[0065] Tower cranes are high-inertia systems. The rigid tower jib, while carrying a heavy load in a slewing motion, requires smooth stopping and accurate positioning. The deceleration process of a tower crane can be divided into three stages: 1) The tower crane rotates at a constant speed, with the jib following the slewing bearing; there is no braking angular acceleration at this stage. 2) When approaching the designated point, a stop command is received, and the slewing mechanism begins to decelerate. Under the influence of angular acceleration, the jib generates a reverse inertial force and begins to periodically oscillate around its changing equilibrium position within the plane of rotation. 3) After decelerating to zero, the jib stops rotating, but due to inertia, it will periodically oscillate around its static equilibrium position within the plane of rotation until it naturally stops under the influence of friction. The inertial force is directly proportional to the acceleration; the greater the acceleration, the stronger the inertial force, the greater the swaying amplitude during deceleration, and the more severe the shaking after stopping. The jib will oscillate back and forth within the plane of rotation due to inertia, and the magnitude of the oscillation is directly proportional to the magnitude of the angular acceleration during deceleration. The load suspended by the jib will oscillate along with it. This situation is very dangerous in actual applications. It would take a long time to eliminate the swaying by relying solely on its own friction, and the swaying process would increase the wear on the internal and external teeth of the slewing bearing, reducing its service life.

[0066] The current solutions to these types of problems are generally:

[0067] Using a torque motor, combined with load and eddy current control torque, achieves smooth speed regulation; however, using a torque motor increases costs, and torque motors are prone to damage and difficult to repair.

[0068] Using a conventional motor and adding algorithms to the frequency converter control, the main method for solving the impact problem during acceleration and deceleration is the S-curve. The acceleration of the S-curve is trapezoidal or triangular, with the slope determined by a constant jerk. During deceleration, the S-curve acceleration is trapezoidal (the description of acceleration during deceleration here is directional). It initially rises with a constant jerk J1, reaches an acceleration limit A, then runs at a constant acceleration A, and finally decreases with a constant jerk J2 until it reaches zero. When using this S-curve as a buffer for rotary motion, in the final stage of deceleration, to prevent a sudden change in output frequency, the acceleration must decrease from A with a constant slope J2 over a fixed time. This process lacks a phase where the acceleration approaches zero to release existing inertial forces, while simultaneously generating relatively small inertial forces. The change in acceleration fails to match the operating characteristics of the rotary mechanism, resulting in a lag angle and oscillation of the tower arm after stopping. Therefore, wear on the gears may still occur.

[0069] To address the aforementioned problems, this embodiment provides a method for reducing the speed of a tower crane's slewing mechanism, such as... Figure 1 As shown, it includes:

[0070] S11: Receive shutdown command;

[0071] S12: Control the rotary mechanism to begin deceleration and gradually increase the deceleration acceleration;

[0072] S13: When the deceleration increases to a preset limit value, the deceleration is constant at the preset limit value;

[0073] S14: When the constant deceleration reaches the preset time, the deceleration acceleration is controlled to gradually decrease until the speed of the rotary mechanism reaches the preset minimum speed value, and the acceleration also reaches the preset minimum acceleration.

[0074] In this embodiment, based on the characteristics of slewing braking, namely that the amplitude of tower arm swing is proportional to the angular acceleration of deceleration, the magnitude of acceleration is adjusted by changing the acceleration deceleration curve, and the operation of ordinary motor is controlled by frequency converter to maintain the smooth stopping of the slewing mechanism and reduce the amplitude of tower arm swing after stopping.

[0075] Upon receiving a stop command, the control rotary mechanism begins to decelerate, and the deceleration acceleration gradually increases. When the deceleration acceleration increases to a preset limit value, the increase in deceleration acceleration stops, and the machine decelerates rapidly at a constant acceleration. This is the first process of deceleration, which is denoted as the S-curve portion in this embodiment.

[0076] The S-curve ensures a smooth transition from a constant speed to a rapid deceleration phase, followed by a rapid descent with constant acceleration. After a preset time, the deceleration is gradually reduced until the acceleration reaches zero when the speed of the rotary mechanism is zero. This is the second deceleration process, referred to as the composite curve portion in this embodiment. Gradually reducing the acceleration and slowing down the deceleration releases the inertial force already generated in the S-curve portion and weakens the inertial force to be generated in the composite curve portion. Furthermore, because there are no abrupt changes in acceleration throughout the deceleration process, the grinding degree of the supporting internal and external teeth will not increase.

[0077] Therefore, this application requires an inverter to adjust the acceleration, which outputs a smooth frequency curve that can guarantee a smooth change in acceleration from a fixed frequency to zero over an arbitrarily adjustable time until it gradually approaches zero, in order to control the deceleration motion of the rotating structure.

[0078] In this embodiment, when the speed of the slewing mechanism reaches the preset minimum speed value, the acceleration also reaches the preset minimum acceleration value. This can be considered as the acceleration being zero when the speed of the slewing mechanism is zero. This embodiment does not limit the specific value. It is easy to see that the smaller the preset value, the more stable the deceleration and stopping of the slewing mechanism, and the smaller the influence of the acceleration value on the lag angle of the tower arm slewing.

[0079] The deceleration method for the tower crane slewing mechanism provided in this embodiment includes: receiving a stop command; controlling the slewing mechanism to begin deceleration and gradually increasing the deceleration acceleration; when the deceleration acceleration increases to a preset limit value, maintaining a constant deceleration at the preset limit value; when the constant deceleration reaches a preset time, controlling the deceleration acceleration to gradually decrease until the speed of the slewing mechanism reaches a preset minimum speed value, at which point the acceleration also reaches the preset minimum acceleration. During the deceleration process of the slewing mechanism, the deceleration acceleration initially increases gradually. When the deceleration acceleration increases to the preset limit value, the increase in deceleration acceleration stops, and the mechanism decelerates rapidly at a constant acceleration. After reaching the preset time, the deceleration acceleration is gradually decreased. This gradual decrease in acceleration releases the existing inertial force and weakens the inertial force that will be generated. Throughout the deceleration process, there are no sudden changes in acceleration, thus avoiding increased wear on the internal and external teeth of the support. Without increasing the cost of replacing the torque motor, the influence of the acceleration value on the slewing lag angle of the tower arm is minimized, reducing the sway amplitude of the tower arm after shutdown.

[0080] According to the above embodiments, this embodiment provides a preferred solution, which further includes the following steps before controlling the rotary mechanism to begin deceleration and gradually increasing the deceleration acceleration:

[0081] Get the current operating frequency, preset total downtime, preset constant deceleration frequency percentage, preset constant deceleration time percentage, preset limited acceleration value, and preset stop brake frequency;

[0082] The S-curve deceleration frequency and the composite curve deceleration frequency are obtained based on the current operating frequency and the preset constant deceleration frequency ratio.

[0083] The S-curve deceleration time and the compound curve deceleration time are obtained based on the preset total downtime and the preset constant deceleration time percentage.

[0084] In this embodiment, the current operating frequency (RunFrq) is the operating frequency after receiving the stop command, the preset total stop time (RunTime) is the preset total time from receiving the stop command to completing the deceleration process, the preset constant deceleration frequency ratio (FrqRatio) is the deceleration frequency ratio of the S-curve portion, and the preset constant deceleration time ratio (TimeRatio) is the deceleration time ratio of the S-curve portion. The S-curve deceleration frequency is obtained by using the current operating frequency and the preset constant deceleration frequency ratio. Correspondingly, subtracting the load curve deceleration frequency ratio (1-FrqRatio) from 1 yields the load curve deceleration frequency. The S-curve deceleration time is obtained based on the preset total stop time and the preset constant deceleration time ratio. Correspondingly, subtracting the load curve time ratio (1-TimeRatio) from 1 yields the composite curve deceleration time.

[0085] The preset stop brake frequency mentioned in this embodiment refers to the state in which the output frequency reaches the preset stop brake frequency, which can be regarded as a stop state.

[0086] For the S-curve portion, when the deceleration increases to a preset limit value, the deceleration is constant at the preset limit value, including:

[0087] The acceleration is obtained from the deceleration frequency and deceleration time of the S-curve.

[0088] The slewing mechanism is controlled by accelerometer to begin deceleration, and the deceleration is gradually increased.

[0089] When the deceleration increases to a preset limit value, the rotary mechanism is controlled to decelerate at a constant speed using the preset limit value.

[0090] Based on the integral relationship between jerk, acceleration, and velocity, the jerk JSpeed ​​is calculated as 2 * RunFrq * FrqRatio / (RunTime * TimeRatio)^2;

[0091] Next, calculate the acceleration (ASpeed): ASpeed ​​equals the integral of JSpeed ​​over time. When ASpeed ​​> LimASpeed, ASpeed ​​= LimASpeed. The S-curve ensures that after entering the deceleration phase from a uniform speed, it descends rapidly with constant acceleration.

[0092] like Figure 2 As shown, when deceleration begins in area A, the acceleration gradually increases from zero to the preset limit acceleration value LimASpeed, and then decelerates at a constant LimASpeed, at which point the acceleration is zero.

[0093] For the composite curve portion, when the constant deceleration reaches a preset time, the deceleration acceleration is gradually reduced, including:

[0094] Set the initial values, recursive transformation quantities, and redundancy frequencies of the preset parameters;

[0095] Based on the first function, the frequency change during the deceleration time of the composite curve is obtained;

[0096] The first function is: f(t) = LimASpeed / (1+(a*t)^2);

[0097] Where a is a preset parameter, t is the deceleration time of the compound curve, LimASpeed ​​is the preset limit acceleration value, and f(t) is the acceleration;

[0098] Determine whether the frequency change is within the error range of the compound curve deceleration frequency and the redundant frequency.

[0099] If so, then the current preset parameter is determined as the control parameter;

[0100] If not, then perform recursive calculations on the initial values ​​of the preset parameters based on the recursive transformation amount, and use the recursive result as the preset parameter. Return to the step of obtaining the frequency change amount during the deceleration time of the composite curve according to the first function, until the frequency change amount is within the error of the composite curve deceleration frequency and the redundant frequency.

[0101] The control acceleration is determined based on the control parameters and the first function;

[0102] The control acceleration controls the rotary mechanism to begin deceleration, and then gradually increases the deceleration acceleration, while the control acceleration gradually decreases over time.

[0103] In this embodiment, a first function f(t) = f(t) = LimASpeed / (1 + (a*t)^2) is constructed, where LimASpeed ​​is the acceleration value at the beginning of the composite curve portion, that is, the acceleration connecting with the S-curve portion, a is the variable to be recursively calculated, and t is the time from 0 in the composite curve portion. It can be seen that once a is determined, as t gradually increases, f(t) will gradually decrease from LimASpeed ​​to infinitesimal.

[0104] First, determine the initial value of a preset parameter (denoted as Seta), the recursive transformation quantity (denoted as Daltea), and the redundancy frequency (denoted as ErrFrq);

[0105] Calculate the frequency change of the composite curve portion during the deceleration time under the current conditions, DalteFrq(k), which is the definite integral of f(t) over the time t:0 to the deceleration time: DalteFrq(k) =

[0106] LimASpeed / a(k)*arctan(a(k)*LimASpeed / a(k)*arctan(a(k)*CTime); where when k=0, a(k) is the initial value of the preset parameter Seta, and when k>0, a(k) is the preset parameter calculated recursively in each step, and DalteFrq(k) is the frequency change.

[0107] The determination of whether the frequency change is within the error range of the composite curve deceleration frequency mentioned in this embodiment means that the redundant frequency is used as an adjustment parameter for the error change of the composite curve deceleration frequency to determine whether the frequency change is within the error range.

[0108] Specifically, determine whether the frequency change is less than the deceleration frequency of the composite curve minus the redundant frequency;

[0109] If so, the initial value of the preset parameter is decremented according to the recursive transformation, and the resulting recursive result is used as the preset parameter. a(k) is decremented by Daltea, i.e., a(k) = a(k-1) – Daltea.

[0110] Determine whether the frequency change is greater than the deceleration frequency of the composite curve plus the redundant frequency.

[0111] If so, the initial value of the preset parameter is incremented according to the recursive transformation, and the resulting recursive result is used as the preset parameter. a(k) is incremented by Daltea, that is, a(k) = a(k-1) + Daltea.

[0112] Until the frequency change is greater than the deceleration frequency of the composite curve minus the redundant frequency, and greater than the deceleration frequency of the composite curve plus the redundant frequency.

[0113] When the recursive operation ends, the preset parameters at this point are recorded as control parameters (ContA).

[0114] The control acceleration is determined based on the control parameters and the first function; f(t) = LimASpeed /

[0115] (1+(ContA*t)^2), where t starts from 0.

[0116] like Figure 2 As shown, the acceleration in region B gradually decreases. Once a is determined, as t gradually increases, f(t) will gradually decrease from LimASpeed ​​to infinitesimal.

[0117] The rotary mechanism begins to decelerate based on the controlled acceleration, which gradually decreases over time. This gradual reduction in acceleration and slow deceleration releases the inertial force already generated in the S-curve portion and weakens the inertial force that will be generated in the composite curve portion. Furthermore, because the acceleration remains constant throughout the deceleration process, it does not increase the grinding degree of the supporting internal and external teeth.

[0118] Based on the above embodiments, this embodiment provides a specific implementation method for the deceleration of a tower crane slewing mechanism, which controls the slewing mechanism to begin deceleration based on jerk control and gradually increases the deceleration acceleration, including:

[0119] The corresponding acceleration is obtained from the jerk.

[0120] The corresponding output frequency is obtained based on the acceleration.

[0121] The inverter output is controlled according to the output frequency to slow down the rotary mechanism;

[0122] Correspondingly, controlling the constant deceleration of the rotary mechanism with a preset limit acceleration value includes:

[0123] The corresponding output frequency is obtained based on the preset acceleration value;

[0124] The inverter output is controlled according to the output frequency to slow down the rotary mechanism;

[0125] Correspondingly, the slewing mechanism begins to decelerate according to the controlled acceleration, including:

[0126] The corresponding output frequency is obtained by controlling the acceleration.

[0127] The inverter output is controlled according to the output frequency to slow down the slewing mechanism.

[0128] According to the above embodiments, both the S-curve and the composite curve are controlled by determining the acceleration and then controlling the deceleration of the rotary mechanism. Therefore, the corresponding output frequency can be obtained through the acceleration, and the frequency output is realized through the frequency converter, thereby achieving the regulation of the deceleration process.

[0129] According to the above embodiments, it also includes:

[0130] When the output frequency is not greater than the stop brake frequency, the inverter is stopped and a DC braking current is applied to the rotary motor.

[0131] When the frequency of the composite curve is not greater than the stop brake frequency, it can be considered as a stop, the frequency converter is stopped, and DC braking current is applied to the rotary motor.

[0132] In the above embodiments, the deceleration method of the tower crane slewing mechanism has been described in detail. This application also provides embodiments corresponding to the deceleration device of the tower crane slewing mechanism. It should be noted that this application describes the embodiments of the device part from two perspectives: one is based on the functional module, and the other is based on the hardware.

[0133] From the perspective of functional modules Figure 3 A structural diagram of a speed reduction device for a tower crane slewing mechanism provided in this application embodiment is shown below. Figure 3 As shown, the speed reduction device of the tower crane's slewing mechanism includes:

[0134] Receiver module 31 is used to receive shutdown commands;

[0135] The deceleration module 32 is used to control the rotary mechanism to start decelerating and gradually increase the deceleration acceleration;

[0136] S-curve deceleration module 33 is used to decelerate at a constant preset acceleration value when the deceleration acceleration increases to a preset limit value.

[0137] The compound curve deceleration module 34 is used to control the deceleration acceleration to gradually decrease when the constant deceleration reaches a preset time, until the speed of the rotary mechanism reaches a preset minimum speed value, and the acceleration also reaches a preset minimum acceleration.

[0138] The tower crane slewing mechanism deceleration device provided in this application receives a stop command via a receiving module 31; a deceleration module 32 controls the slewing mechanism to begin deceleration and gradually increases the deceleration acceleration; an S-curve deceleration module 33 decelerates at a preset limit acceleration value when the deceleration acceleration reaches that value; and a compound curve deceleration module 34 controls the deceleration acceleration to gradually decrease after a preset time, until the slewing mechanism reaches a preset minimum speed value, at which point the acceleration also reaches the preset minimum acceleration. During the deceleration process, the deceleration acceleration gradually increases initially. Once it reaches the preset limit acceleration value, the increase stops, and the mechanism decelerates rapidly at a constant acceleration. After a preset time, the deceleration acceleration gradually decreases, releasing existing inertial forces and weakening future inertial forces. Throughout the deceleration process, there are no sudden changes in acceleration, preventing an increase in the wear resistance of the inner and outer teeth of the support. Without increasing costs by replacing the torque motor, the impact of acceleration on the tower boom slewing lag angle is minimized, reducing the tower boom swing amplitude after shutdown.

[0139] Since the embodiments of the apparatus and the embodiments of the method correspond to each other, please refer to the description of the embodiments of the method for the embodiments of the apparatus, which will not be repeated here.

[0140] Figure 4 A structural diagram of a speed reduction device for another tower crane slewing mechanism provided in this application embodiment is shown below. Figure 4 As shown, the speed reduction device of the tower crane slewing mechanism includes: a memory 40 for storing computer programs;

[0141] The processor 41 is used to execute a computer program to implement the steps of the method for obtaining user operating habit information as described in the above embodiment (deceleration method of tower crane slewing mechanism).

[0142] The deceleration device for the tower crane slewing mechanism provided in this embodiment may include, but is not limited to, smartphones, tablets, laptops, or desktop computers.

[0143] The processor 41 may include one or more processing cores, such as a quad-core processor or an octa-core processor. The processor 41 may be implemented using at least one of the following hardware forms: Digital Signal Processor (DSP), Field-Programmable Gate Array (FPGA), or Programmable Logic Array (PLA). The processor 41 may also include a main processor and a coprocessor. The main processor, also known as the Central Processing Unit (CPU), is used to process data in the wake-up state; the coprocessor is a low-power processor used to process data in the standby state. In some embodiments, the processor 41 may integrate a Graphics Processing Unit (GPU), which is responsible for rendering and drawing the content to be displayed on the screen. In some embodiments, the processor 41 may also include an Artificial Intelligence (AI) processor, which handles computational operations related to machine learning.

[0144] The memory 40 may include one or more computer-readable storage media, which may be non-transitory. The memory 40 may also include high-speed random access memory and non-volatile memory, such as one or more disk storage devices or flash memory devices. In this embodiment, the memory 40 is used to store at least the following computer program 401, which, after being loaded and executed by the processor 41, is capable of implementing the relevant steps of the deceleration method for the tower crane slewing mechanism disclosed in any of the foregoing embodiments. In addition, the resources stored in the memory 40 may also include an operating system 402 and data 403, and the storage method may be temporary or permanent storage. The operating system 402 may include Windows, Unix, Linux, etc. The data 403 may include, but is not limited to, data involved in implementing the deceleration method for the tower crane slewing mechanism.

[0145] In some embodiments, the speed reduction device of the tower crane slewing mechanism may further include a display screen 42, an input / output interface 43, a communication interface 44, a power supply 45, and a communication bus 46.

[0146] Those skilled in the art will understand that Figure 4 The structure shown does not constitute a limitation on the speed reduction device of the tower crane slewing mechanism and may include more or fewer components than shown.

[0147] The deceleration device for the tower crane slewing mechanism provided in this application embodiment includes a memory and a processor. When the processor executes the program stored in the memory, it can implement the following method: a deceleration method for the tower crane slewing mechanism, including: receiving a stop command; controlling the slewing mechanism to start deceleration and gradually increasing the deceleration acceleration; when the deceleration acceleration increases to a preset limit acceleration value, decelerating at a constant preset acceleration value; when the constant deceleration reaches a preset time, controlling the deceleration acceleration to gradually decrease until the speed of the slewing mechanism reaches a preset minimum speed value, and the acceleration also reaches a preset minimum acceleration. During the deceleration process of the slewing mechanism, the deceleration acceleration first gradually increases. When the deceleration acceleration increases to a preset limit acceleration value, the increase in deceleration acceleration stops, and the mechanism decelerates rapidly at a constant acceleration. When the preset time is reached, the deceleration acceleration is controlled to gradually decrease. Gradually decreasing the acceleration and slowly decelerating releases the inertial force that has already been generated and weakens the inertial force that will be generated. During the entire deceleration period, there is no sudden change in acceleration, and the grinding degree of the internal and external teeth of the support is not increased. Without increasing costs by replacing the torque motor, the impact of acceleration value on the tower boom slewing lag angle is minimized, thus reducing the tower boom swing amplitude after shutdown.

[0148] Finally, this application also provides an embodiment corresponding to a computer-readable storage medium. The computer-readable storage medium stores a computer program, which, when executed by a processor, implements the steps described in the above embodiment of the deceleration method for the tower crane slewing mechanism.

[0149] It is understood that if the methods in the above embodiments are implemented as software functional units and sold or used as independent products, they can be stored in a computer-readable storage medium. Based on this understanding, the technical solution of this application, in essence, or the part that contributes to the prior art, or all or part of the technical solution, can be embodied in the form of a software product. This computer software product is stored in a storage medium and executes all or part of the steps of the methods in the various embodiments of this application. The aforementioned storage medium includes various media capable of storing program code, such as USB flash drives, portable hard drives, read-only memory (ROM), random access memory (RAM), magnetic disks, or optical disks.

[0150] The computer-readable storage medium provided in this embodiment stores a computer program. When the processor executes the program, the following method can be implemented: a deceleration method for a tower crane slewing mechanism. The deceleration method for a tower crane slewing mechanism includes: receiving a stop command; controlling the slewing mechanism to begin deceleration and gradually increasing the deceleration acceleration; when the deceleration acceleration increases to a preset limit acceleration value, decelerating at a constant preset acceleration value; when the constant deceleration reaches a preset time, controlling the deceleration acceleration to gradually decrease until the speed of the slewing mechanism reaches a preset minimum speed value, at which point the acceleration also reaches the preset minimum acceleration. During the deceleration process of the slewing mechanism, the deceleration acceleration first gradually increases. When the deceleration acceleration increases to the preset limit acceleration value, the increase in deceleration acceleration stops, and the mechanism decelerates rapidly at a constant acceleration. When the preset time is reached, the deceleration acceleration is controlled to gradually decrease. Gradually decreasing the acceleration and slowly decelerating releases the inertial force that has already been generated and weakens the inertial force that will be generated. During the entire deceleration period, there is no sudden change in acceleration, and the grinding degree of the internal and external teeth of the support is not increased. Without increasing costs by replacing the torque motor, the impact of acceleration value on the tower boom slewing lag angle is minimized, thus reducing the tower boom swing amplitude after shutdown.

[0151] The above provides a detailed description of the deceleration method, apparatus, and medium for the tower crane slewing mechanism provided in this application. The various embodiments in the specification are described in a progressive manner, with each embodiment focusing on its differences from other embodiments. Similar or identical parts between embodiments can be referred to interchangeably. For the apparatus disclosed in the embodiments, since it corresponds to the method disclosed in the embodiments, the description is relatively simple; relevant parts can be referred to in the method section. It should be noted that those skilled in the art can make several improvements and modifications to this application without departing from the principles of this application, and these improvements and modifications also fall within the protection scope of the claims of this application.

[0152] It should also be noted that, in this specification, relational terms such as "first" and "second" are used only to distinguish one entity or operation from another, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Furthermore, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a process, method, article, or apparatus. Without further limitations, an element defined by the phrase "comprising one..." does not exclude the presence of other identical elements in the process, method, article, or apparatus that includes said element.

Claims

1. A method for decelerating a slewing mechanism of a tower crane, characterized in that The method comprises the following steps: receiving a shutdown instruction; controlling the rotary mechanism to start deceleration and gradually increase the deceleration acceleration; when the deceleration acceleration increases to a preset limited acceleration value, constant deceleration is performed at the preset limited acceleration value; when constant deceleration reaches a preset time, the deceleration acceleration is gradually reduced until the speed of the rotary mechanism reaches a preset minimum speed value and the acceleration also reaches a preset minimum acceleration; wherein, before the step of controlling the rotary mechanism to start deceleration and gradually increase the deceleration acceleration, the method further comprises the following steps: obtaining a current running frequency, a preset total shutdown time, a preset constant deceleration frequency ratio, a preset constant deceleration time ratio, a preset limited acceleration value, and a preset shutdown brake frequency; obtaining an S-curve deceleration frequency and a composite curve deceleration frequency according to the current running frequency and the preset constant deceleration frequency ratio; obtaining an S-curve deceleration time and a composite curve deceleration time according to the preset total shutdown time and the preset constant deceleration time ratio; wherein, the step of controlling the deceleration acceleration to gradually reduce when constant deceleration reaches a preset time comprises: setting an initial value of a preset parameter, a recursive transformation amount, and a redundant frequency; obtaining a frequency variation amount within the composite curve deceleration time according to a first function; the first function is: f(t) = LimASpeed / (1+(a*t)^2); wherein, a is the preset parameter, t is the composite curve deceleration time, LimASpeed is the preset limited acceleration value, and f(t) is the acceleration; determining whether the frequency variation amount is within an error of the composite curve deceleration frequency from the redundant frequency; if yes, determining the current preset parameter as a control parameter; if no, recursively operating the initial value of the preset parameter according to the recursive transformation amount to obtain a recursive result as the preset parameter, and returning to the step of obtaining the frequency variation amount within the composite curve deceleration time according to the first function until the frequency variation amount is within the error of the composite curve deceleration frequency from the redundant frequency; determining a control acceleration according to the control parameter and the first function; controlling the rotary mechanism to start deceleration according to the control acceleration, wherein the control acceleration gradually decreases over time.

2. The method of claim 1, wherein the method further comprises: the step of constant deceleration at the preset limited acceleration value when the deceleration acceleration increases to the preset limited acceleration value comprises: obtaining a jerk according to the S-curve deceleration frequency and the S-curve deceleration time; controlling the rotary mechanism to start deceleration and gradually increase the deceleration acceleration according to the jerk; when the deceleration acceleration increases to the preset limited acceleration value, controlling the rotary mechanism to constant deceleration at the preset limited acceleration value.

3. The method of claim 2, wherein the step of reducing the speed of the slewing mechanism of the tower crane is performed by the controller. the step of controlling the rotary mechanism to start deceleration and gradually increase the deceleration acceleration according to the jerk comprises: obtaining a corresponding acceleration according to the jerk; obtaining a corresponding output frequency according to the acceleration; controlling the frequency converter to output according to the output frequency to make the rotary mechanism decelerate; correspondingly, the step of controlling the rotary mechanism to constant deceleration at the preset limited acceleration value comprises: According to the preset limited acceleration value, a corresponding output frequency is obtained; According to the output frequency, the frequency converter output is controlled, so that the slewing mechanism is decelerated; Correspondingly, the control of the slewing mechanism to start deceleration according to the control acceleration comprises: According to the control acceleration, a corresponding output frequency is obtained; According to the output frequency, the frequency converter output is controlled, so that the slewing mechanism is decelerated.

4. The method of claim 3, wherein the method further comprises: Further comprising: When the output frequency is not greater than the parking brake frequency, the frequency converter is controlled to stop, and the slewing motor is input with a direct-current braking current.

5. The method of claim 1, wherein the method further comprises: According to the first function, a frequency change amount in the composite curve deceleration time is obtained, comprising: According to a second function, an integral value of the first function in the composite curve deceleration time is obtained; The second function is: DalteFrq(k) = LimASpeed / a(k)* arctan(a(k)* CTime); Wherein, when k=0, a(k) is the initial value of the preset parameter, when k>0, a(k) is the preset parameter calculated by each step recursion, DalteFrq(k) is the frequency change amount, and CTime is the composite curve deceleration time.

6. A speed reduction device of a slewing mechanism of a tower crane, characterized by comprising: Comprising: A receiving module is configured to receive a parking instruction; A deceleration module is configured to control the slewing mechanism to start deceleration and gradually increase the deceleration acceleration; An S-curve deceleration module is configured to decelerate at a constant preset limited acceleration value when the deceleration acceleration increases to the preset limited acceleration value; A composite curve deceleration module is configured to gradually decrease the deceleration acceleration until the speed of the slewing mechanism reaches a preset minimum speed value and the acceleration reaches a preset minimum acceleration when the constant deceleration reaches a preset time. Before the control of the slewing mechanism to start deceleration and gradually increase the deceleration acceleration, further comprising: Obtaining a current running frequency, a preset parking total time, a preset constant deceleration frequency ratio, a preset constant deceleration time ratio, a preset limited acceleration value, and a preset parking brake frequency; According to the current running frequency and the preset constant deceleration frequency ratio, an S-curve deceleration frequency and a composite curve deceleration frequency are obtained; According to the preset parking total time and the preset constant deceleration time ratio, an S-curve deceleration time and a composite curve deceleration time are obtained. When the constant deceleration reaches a preset time, the deceleration acceleration is gradually decreased, comprising: Setting an initial value, a recursive transformation amount, and a redundant frequency of a preset parameter; According to a first function, a frequency change amount in the composite curve deceleration time is obtained; The first function is: f(t) = LimASpeed / (1+(a*t)^2); Wherein, a is the preset parameter, t is the composite curve deceleration time, LimASpeed is the preset limited acceleration value, and f(t) is the acceleration; It is judged whether the frequency change amount is within an error of the composite curve deceleration frequency from the redundant frequency; If yes, the current preset parameter is determined as a control parameter. If not, the initial value of the preset parameter is recursively operated according to the recursive transformation amount, and the recursive result is taken as the preset parameter. The control acceleration is determined according to the control parameter and the first function; The control acceleration is gradually reduced over time.

7. A speed reduction device of a slewing mechanism of a tower crane, characterized by comprising: The computer readable storage medium stores a computer program, and the computer program is executed by the processor to implement the steps of the tower crane slewing mechanism deceleration method. The computer readable storage medium stores a computer program, and the computer program is executed by the processor to implement the steps of the tower crane slewing mechanism deceleration method. ​ 8. A computer-readable storage medium, characterized in that, ​

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