A method and system for smooth acceleration and deceleration control of an automatic hoist

Abstract

The present application relates to the technical field of automatic control, and especially relates to a kind of automatic hoist smooth acceleration and deceleration control method and system, the method comprises: obtaining synchronous data sequence including the effective current of drive motor, the cumulative angular displacement of drum and motor angular velocity;According to motor angular velocity, calculate angular acceleration, determine equivalent mass based on the ratio of the difference between total driving torque and friction torque and angular acceleration;According to cumulative angular displacement, calculate the length of suspension, determine radius amplification ratio and strain deviation ratio accordingly, and the product of the two is flexible correction operator;Determine drive compensation based on equivalent mass, flexible correction operator and reference acceleration;The ratio of feedback speed and displacement absolute deviation is used as damping constraint quantity, and the difference between drive compensation and damping constraint quantity is used to control frequency converter.The present application improves the response characteristics of hoist and reduces the probability of load oscillation through real-time calculation of dynamic parameters and flexible compensation.

Description

Technical Field

[0001] This invention relates to the field of automatic control technology, and in particular to a smooth acceleration and deceleration control method and system for an automatic hoist. Background Technology

[0002] As a core piece of equipment in cable material production lines for achieving vertical material displacement, the smoothness of automatic hoists directly affects material conveying efficiency and the fatigue life of the mechanical structure. To ensure accurate docking of the hoist cage between different workstations and to prevent material spillage, smooth acceleration and deceleration control of the drive motor is usually required to buffer the mechanical impact during start-up and shutdown.

[0003] Existing technologies mostly employ S-curve algorithms based on fixed-length segment division, using polynomials or trigonometric functions to plan the motion trajectory offline by presetting the maximum rate of change of acceleration. This method, by dividing the motion process into specific stages such as acceleration, uniform acceleration, and deceleration, improves the mechanical vibration of the system caused by acceleration step jumps to some extent.

[0004] However, traditional control strategies have limitations when handling cable material conveying tasks with variable loads and long strokes. First, the bulk density and total mass of the cable material fluctuate nonlinearly during batch switching. Existing algorithms are mostly based on constant mass models and cannot calculate the actual inertial parameters of the controlled object in real time. Due to the mapping deviation between the control law and the actual load mass, the motor output torque is difficult to accurately offset the inertial torque caused by load fluctuations, easily inducing physical speed fluctuations at acceleration / deceleration switching points. Second, considering that the number of overlapping layers of the wire rope on the drum changes the actual lever arm during long-distance operation of the hoist, and the elastic strain of the rope itself changes dynamically with the load and suspension length, this nonlinear characteristic of the transmission path causes a dynamic mismatch between the nominal control quantity and the actual executed displacement. This results in the residual kinetic energy at the deceleration end being unable to be effectively suppressed, easily causing low-frequency simple harmonic vibrations in the cage, which not only reduces the stopping positioning accuracy but also increases the abnormal fatigue wear of the transmission components. Summary of the Invention

[0005] To address the aforementioned technical problems of unstable hoist operation and low-frequency simple harmonic vibration caused by the lack of real-time load sensing and nonlinear interference in the transmission path, this invention provides solutions in the following aspects.

[0006] In a first aspect, the present invention provides a method for smooth acceleration and deceleration control of an automatic hoist, the method comprising the steps of: Synchronization data of the hoist is acquired to construct a synchronization data sequence, which includes the effective current of the drive motor, the cumulative angular displacement of the drum, and the angular velocity of the motor. The angular acceleration of the drive motor is calculated based on the angular velocity of the motor in the synchronization data sequence. The total driving torque of the drive motor is determined based on the effective current. The frictional resistance torque is determined based on the motor angular velocity and a preset friction model. The difference between the total driving torque and the frictional resistance torque is calculated. The equivalent mass of the hoist is determined based on the ratio of the difference to the angular acceleration. The suspension length of the wire rope is calculated based on the cumulative angular displacement of the drum. The angular acceleration of the hoist is determined based on the cumulative angular displacement of the drum. The radius enlargement ratio of the fixed drum is used to determine the strain deviation ratio of the wire rope based on the equivalent mass and suspension length. The radius enlargement ratio is multiplied by the strain deviation ratio to obtain the hoist's flexibility correction operator. Based on the equivalent mass, the flexibility correction operator, and the hoist's reference acceleration, the drive compensation amount is determined. The absolute deviation between the preset target displacement and the current displacement determined based on the cumulative angular displacement of the drum is calculated. The ratio of the feedback speed determined based on the motor angular velocity to the absolute deviation is used as the damping constraint amount. The difference between the drive compensation amount and the damping constraint amount is used as the control voltage and output to the drive frequency converter to regulate the hoist's operation.

[0007] This invention calculates the equivalent mass of the hoist using synchronous data sequences. Considering the fluctuations in system dynamic parameters caused by wire rope winding and load changes during hoist operation, it utilizes real-time differential feedback of the total driving torque and frictional resistance torque to dynamically track the system's inertial characteristics. Based on this, a flexible correction operator is obtained by mapping the radius amplification ratio and strain deviation ratio. This operator characterizes the Hooke's law deformation of the wire rope at different suspension lengths and the kinematic nonlinear deviations caused by multi-layer winding of the drum, compensating for elastic displacements that cannot be covered by traditional rigid models. By combining damping constraints with nonlinear adjustment of the feedback speed based on absolute displacement deviation, the control voltage can perform feedforward compensation and feedback constraints according to the actual physical state of the load. This improves the torque distribution of the hoist during smooth acceleration and deceleration, further reducing the probability of severe oscillations in the suspended load at start-up and shutdown, and improving the smoothness of the automatic hoisting system under variable load conditions.

[0008] Preferably, the step of calculating the angular acceleration of the drive motor based on the motor angular velocity in the synchronous data sequence includes: taking any moment during the operation of the hoist as the current moment; calculating the difference between the motor angular velocity at the current moment and the motor angular velocity at the previous moment in the synchronous data sequence; and using the ratio of the difference to a preset sampling period as the angular acceleration of the drive motor at the current moment.

[0009] Preferably, the step of determining the total driving torque of the drive motor based on the effective current and determining the frictional resistance torque based on the motor angular velocity and a preset friction model includes: obtaining the torque constant of the drive motor, multiplying the torque constant by the effective current to obtain the total driving torque of the drive motor; obtaining the viscous friction coefficient and the static frictional resistance torque of the hoist, multiplying the viscous friction coefficient by the motor angular velocity, and then adding it to the static frictional resistance torque to obtain the frictional resistance torque.

[0010] This invention uses the torque constant to calculate the total driving torque and combines the viscous friction coefficient and static friction torque to evaluate the friction resistance torque. Considering the internal loss characteristics of the mechanical transmission system, the invention improves the extraction accuracy of the net driving torque in the equivalent mass calculation process by deconstructing the driving force and resistance terms.

[0011] Preferably, determining the radius enlargement ratio of the drum based on the cumulative angular displacement of the drum includes: obtaining the standard radius of the drum and the diameter of the wire rope in the hoist; removing the cumulative angular displacement of the drum to a single-turn radian value and performing a floor operation to obtain the increment of the number of winding layers of the wire rope; multiplying the increment of the number of winding layers by the diameter of the wire rope and then adding it to the standard radius of the drum to obtain the equivalent radius of the drum; and using the ratio of the equivalent radius of the drum to the standard radius as the radius enlargement ratio of the drum.

[0012] This invention calculates the incremental number of rope layers based on cumulative angular displacement. Taking into account the increase in physical radius caused by the overlapping and winding of the wire rope on the drum, the transmission ratio model is dynamically corrected by the radius amplification ratio, thereby improving the accuracy of the mapping relationship between rotational motion and linear displacement.

[0013] Preferably, determining the strain deviation ratio of the wire rope based on the equivalent mass and suspension length includes: obtaining the gravitational acceleration of the hoist and the flexibility constant of the wire rope; multiplying the equivalent mass, gravitational acceleration, and flexibility constant of the hoist to obtain the rope elastic deviation; adding the suspension length to the rope elastic deviation to obtain the equivalent suspension length; and using the ratio of the equivalent suspension length to the suspension length as the strain deviation ratio.

[0014] This invention obtains the elastic deviation of the rope by using equivalent mass and flexibility constant. Considering the influence of the wire rope's self-weight and elastic modulus on position control when the hoist is at different depths in the shaft, the spatial position offset of the load is evaluated by the strain deviation ratio, which reduces the interference of cumulative flexibility error during long-distance hoisting.

[0015] Preferably, the step of calculating the suspension length of the wire rope based on the cumulative angular displacement of the drum includes: obtaining a preset initial suspension length and the standard radius of the drum; multiplying the cumulative angular displacement of the drum by the standard radius of the drum to obtain the winding displacement of the wire rope; and taking the difference between the initial suspension length and the winding displacement of the wire rope as the suspension length of the wire rope.

[0016] Preferably, determining the drive compensation amount based on the equivalent mass, the flexible correction operator, and the reference acceleration of the hoist includes: obtaining the gravitational acceleration and voltage conversion coefficient of the hoist; adding the reference acceleration of the hoist to the gravitational acceleration to obtain the total reference acceleration; and multiplying the equivalent mass, the flexible correction operator, the total reference acceleration, and the voltage conversion coefficient to obtain the drive compensation amount.

[0017] This invention combines the reference acceleration and gravitational acceleration into a total reference acceleration, and uses the drive compensation amount determined by the flexible correction operator to play a feedforward regulation role, thereby improving the inverter's following response characteristics to dynamic given commands and reducing the probability of hysteresis error in the system during heavy load acceleration.

[0018] Preferably, obtaining the damping constraint includes: obtaining a preset damping strength coefficient and the current radius of the drum; multiplying the motor angular velocity, the current radius of the drum, and the damping strength coefficient to obtain the equivalent damping speed; and using the ratio of the equivalent damping speed to the absolute deviation as the damping constraint.

[0019] This invention calculates the equivalent damped velocity using the current radius and damping strength coefficient, and performs dynamic nonlinear feedback on the velocity loop through the damping constraint. Considering the displacement convergence requirement when the hoist approaches the target position, the damping of the system is enhanced when the absolute deviation decreases, thereby improving the running stability of the load at the braking end and further reducing the oscillation frequency during the positioning process.

[0020] Preferably, the acquisition of the effective current of the drive motor includes: taking any moment during the operation of the hoist as the current moment, acquiring the stator current of the drive motor at the current moment, the effective current at the previous moment, and a preset filter coefficient; multiplying the stator current by the preset filter coefficient to obtain the current weighted current; multiplying the complement of the preset filter coefficient by the effective current at the previous moment to obtain the historical weighted current; and adding the current weighted current to the historical weighted current to obtain the effective current at the current moment.

[0021] In a second aspect, the present invention provides a smooth acceleration and deceleration control system for an automatic hoist. The automatic hoist smooth acceleration and deceleration control system includes a memory and a processor. The memory stores computer program instructions, and when the computer program instructions are executed by the processor, an automatic hoist smooth acceleration and deceleration control method of the first aspect of the present invention is implemented.

[0022] By adopting the above technical solution, a computer program for the smooth acceleration and deceleration control method of an automatic hoist of the first aspect of the present invention is generated and stored in a memory so that it can be loaded and executed by a processor. A terminal device can then be made based on the memory and the processor for convenient use.

[0023] The beneficial effects of this invention are as follows: By calculating the equivalent mass in real time and using a flexible correction operator, this invention incorporates the strain characteristics of the wire rope and the nonlinear geometric changes in the number of rope layers on the drum into the closed-loop control model, improving the dynamic adaptability of the hoist under varying loads and lengths. This invention combines the feedforward effect of the drive compensation with the feedback constraint of the damping constraint, utilizing the control voltage to perform multi-dimensional physical adjustments to the drive inverter, reducing the risk of mechanical fatigue caused by flexible impacts during acceleration and deceleration transitions, and improving the comfort of system operation. Furthermore, by physically modeling the synchronous data sequence, this invention achieves full-link perception of the hoist, from the motor's electrical characteristics to the rope's mechanical characteristics, reducing the impact of environmental disturbances on positioning accuracy and improving the operational reliability of the automatic hoisting system in complex shaft environments. Attached Figure Description

[0024] Figure 1 A flowchart of a smooth acceleration and deceleration control method for an automatic hoist provided in an embodiment of the present invention; Figure 2 The dynamic response curves of the equivalent mass and flexible correction operator provided in the embodiments of the present invention; Figure 3 This is a structural block diagram of an automatic hoist smooth acceleration and deceleration control system provided in an embodiment of the present invention. Detailed Implementation

[0025] The first aspect of this invention provides a method for smooth acceleration and deceleration control of an automatic hoist, such as... Figure 1 As shown, the method includes steps S100-S400: Step S100: Obtain the synchronization data of the hoist to construct a synchronization data sequence, the synchronization data sequence including the effective current of the drive motor, the cumulative angular displacement of the drum, and the angular velocity of the motor.

[0026] It should be noted that the dynamic behavior of the hoist during the vertical transport of cable material is affected by the coupling of multiple physical variables. In order to accurately describe the real-time state of the hoist, this invention needs to calibrate the inherent physical properties of the hoist and ensure that feedback signals such as current, displacement, and velocity remain synchronized in the time domain, thereby avoiding dynamic modeling distortion caused by signal phase differences.

[0027] First, initialize the inherent physical parameters of the hoist. The hoist includes a drive motor, drum, and cage. Based on this, its inherent physical parameters include: the torque constant of the drive motor, the standard radius of the drum, the diameter of the wire rope, the viscous friction coefficient of the hoist, the static friction torque of the hoist, the gravitational acceleration of the hoist, and the flexibility constant of the wire rope. These parameters are pre-stored in the controller's non-volatile memory as the physical reference for constructing the adaptive control law. These parameters can also be obtained based on the drive motor nameplate parameters or through offline experiments.

[0028] Then, real-time operational data is collected synchronously. It should be noted that the stator current of the hoist drive motor reflects the power output of the actuator, while the displacement and angular velocity of the drum reflect the motion response of the hoist. Synchronization of these three parameters is a prerequisite for achieving variable load observation. The preset sampling period needs to be set according to the motor's maximum speed and smoothness requirements: for high dynamic response scenarios, the preset sampling period should be reduced, such as 1ms to 2ms; for high inertia scenarios, the preset sampling period needs to be increased, such as 5ms to 10ms. In this embodiment, the preset sampling period is preferably 2ms.

[0029] Finally, the sampled signals are smoothed and preprocessed to construct a data sequence. It should be noted that severe electromagnetic interference exists in industrial environments; directly using the sampled stator current will cause high-frequency jitter in the quality observer. Therefore, a filtering algorithm is needed to extract the true signal envelope.

[0030] Specifically, for any given moment, a first-order low-pass filter is used to perform noise reduction on the stator current to obtain the effective current, which satisfies the following relationship: ; in, , They are time points ,time The effective current; It is a moment Stator current; These are the preset filter coefficients.

[0031] It should be further noted that the value of the preset filter coefficient needs to be set according to the severity of the electromagnetic environment of the hoist and the frequency of load fluctuations: for operating scenarios with severe inverter harmonic interference and dense signal spikes, the preset filter coefficient should be reduced, such as to 0.1 to 0.2, to enhance the suppression of high-frequency noise and ensure the smoothness of the effective current; for sampling scenarios with frequent load switching and the need to quickly capture transient load changes, the preset filter coefficient can be appropriately increased, such as to 0.4 to 0.6, to reduce the phase lag of signal processing and improve response sensitivity. In this embodiment, the preset filter coefficient is preferably 0.3.

[0032] Based on this, the controller arranges the effective current, cumulative angular displacement of the drum, and angular velocity of the motor acquired in each sampling cycle according to the sampling time sequence, thereby obtaining a synchronous data sequence composed of multiple sampling points, which is used to characterize the real-time dynamic trajectory of the hoist during operation.

[0033] Thus, a synchronous data sequence consisting of effective current, cumulative angular displacement of the drum, and motor angular velocity was obtained.

[0034] Step S200: Calculate the angular acceleration of the drive motor based on the motor angular velocity in the synchronous data sequence; determine the total drive torque of the drive motor based on the effective current; determine the frictional resistance torque based on the motor angular velocity and the preset friction model; calculate the difference between the total drive torque and the frictional resistance torque; and determine the equivalent mass of the hoist based on the ratio of the difference to the angular acceleration.

[0035] It should be noted that, considering the nonlinear fluctuations in the bulk density and total mass of materials during actual operating conditions such as batch switching in cable material production, which in turn causes real-time changes in system inertia, in order to accurately capture this dynamic physical process, avoid control misalignment caused by using fixed parameters, and achieve dynamic matching between control commands and actual loads, this embodiment transforms the material weight, which cannot be directly measured, into an evaluable equivalent mass index through the causal mapping relationship between driving torque and motion response, thereby providing an accurate inertial reference for subsequent smooth control.

[0036] First, the angular acceleration of the drive motor is calculated using the cumulative angular displacement of the drum in the synchronous data sequence. It should be noted that acceleration is a direct kinematic characteristic reflecting the effect of torque; in vertical conveying scenarios, simple velocity feedback cannot isolate the gravity and inertial terms. This invention uses high-frequency differential analysis on the real-time acquired angular velocity to capture the dynamic transient process of the hoist during start-up and shutdown, thereby providing the necessary second-order kinematic derivative information for the dynamic equations.

[0037] Specifically, for any given moment, the motor angular velocity at that moment and the previous moment are extracted, and differential calculation is performed using a preset sampling period to obtain the motor angular acceleration at that moment.

[0038] Furthermore, to avoid numerical calculation singularities caused by the angular acceleration approaching zero during the uniform speed operation phase of the hoist, this invention introduces a state discrimination mechanism: when the absolute value of the motor angular acceleration is detected to be greater than a preset acceleration threshold, the hoist is determined to be in a non-steady-state motion phase, and the equivalent mass calculation logic is initiated at this time; if the absolute value of the motor angular acceleration is less than or equal to the preset acceleration threshold, the equivalent mass of the previous moment is used as the calculation result of the current moment; if the hoist is in a uniform speed or stationary state from the start-up phase, such as a second start-up, the equivalent mass is taken as a preset reference mass, such as the weight of the cage itself.

[0039] The preset acceleration threshold value needs to be set according to the encoder's line count and the mechanical vibration level of the hoist: for high-precision encoders and scenarios with small transmission backlash, the preset acceleration threshold needs to be reduced, such as to 0.01. Up to 0.03 To improve the sensitivity to minute load fluctuations; for operating conditions with significant mechanical backlash or high signal noise, the preset acceleration threshold should be appropriately increased, such as setting it to 0.05. Up to 0.1 To avoid spurious calculation results caused by numerical fluctuations, in this embodiment, the preset acceleration threshold is preferably 0.05. .

[0040] Then, the equivalent mass of the hoist is calculated. It should be noted that the total load of the hoist consists of the cage's own weight, the material mass, and the operating resistance. Conventional weighing methods cannot eliminate the interference of wire rope tension and friction. This invention constructs an energy balance equation based on the rotational form of Newton's second law, subtracts the modeled frictional resistance torque from the motor's electromagnetic torque, and utilizes the mapping relationship between the remaining net driving torque and acceleration to achieve real-time online estimation of the hoist's dynamic inertial parameters.

[0041] Based on the above logic, the equivalent quality satisfies the following relationship: ; in, It is the moment of hoisting Equivalent quality; It is the torque constant of the drive motor; It is a moment The effective current; It is the viscous friction coefficient of the elevator; It is a moment The angular velocity of the motor; It is the static frictional resistance torque of the hoist; It is the standard radius of the roll; It is a moment The angular acceleration of the motor.

[0042] In this relation, Characterizes the drive motor at time The total driving torque generated; and The viscous loss torque and the inherent static friction loss, which vary with speed, are respectively characterized. The sum of the two constitutes the resistance torque term of the hoist. The numerator is obtained by subtracting the resistance torque term from the total driving torque, and the net driving torque used to overcome the inertia of the hoist and generate a motion response is extracted. This equation maps angular acceleration in rotational dynamics to the linear acceleration dimension at the load end. Through real-time calculation of the ratio of net driving torque to motion response, it can pinpoint the magnitude of inertia, including the cage and internal cable components, online.

[0043] Thus, the equivalent mass of the hoist at each moment was obtained.

[0044] Step S300: Calculate the suspension length of the wire rope based on the cumulative angular displacement of the drum; determine the radius amplification ratio of the drum based on the cumulative angular displacement of the drum, and determine the strain deviation ratio of the wire rope based on the equivalent mass and suspension length; multiply the radius amplification ratio and the strain deviation ratio to obtain the flexible correction operator of the hoist.

[0045] It should be noted that during the vertical lifting process of the hoist, the number of overlapping layers of the wire rope on the drum changes the actual force arm as the displacement increases. Furthermore, as a flexible medium, the wire rope exhibits significant elastic displacement deviation under variable loads. To eliminate the geometric and elastic nonlinear interference in the transmission path, this invention constructs a dimensionless correction operator to correct the nominal physical parameters in real time, thereby ensuring strict consistency between the control commands and the displacement of the end effector.

[0046] First, the geometric correction term for the hoist's drive path is calculated. It should be noted that for each revolution of the drum, its equivalent radius increases by the thickness of a wire rope diameter. This step-like radius change directly affects the efficiency of converting motor torque into lifting force. This invention dynamically determines the current number of rope layers by real-time monitoring of the drum's cumulative angular displacement, providing an accurate geometric gain reference for torque compensation.

[0047] Specifically, for any given moment, the cumulative angular displacement of the drum at that moment is extracted, divided by the single-turn radian value, and rounded down to identify the current number of stacked layers of the wire rope on the drum. Then, the product of the number of layers and the diameter of the wire rope is added to the standard radius of the drum to construct a geometric correction term that reflects the actual change in lever arm.

[0048] Then, the elastic correction term for the hoist's transmission path is calculated. It should be noted that the elastic elongation of the wire rope is proportional to the suspension length and load mass. In deep well or high-level conveying scenarios, this elastic deformation can cause the actual position of the cage to lag behind the encoder's feedback position. This invention introduces an equivalent mass and uses a variable-weight form of Hooke's law to calculate the percentage of displacement deviation caused by elastic deformation, thereby eliminating the spring effect generated by flexible transmission.

[0049] Specifically, for any given moment, the real-time static tension is calculated using the equivalent mass and gravitational acceleration of the hoist at that moment. Combined with the flexibility constant of the wire rope and the suspension length at that moment, it is converted into a proportional coefficient that reflects the strain characteristics per unit length, thereby constructing an elastic correction term that reflects the flexible deformation of the rope.

[0050] Finally, a flexible correction operator for the hoist is obtained through fusion. It should be noted that transmission errors are not simply a linear superposition of geometric and elastic deviations, but rather exhibit a mutually penetrating and coupled relationship. Changes in the geometric radius affect the tension distribution, while elastic elongation reacts to the effective rope length. This invention uses a product operator to nonlinearly fuse these two factors, constructing a comprehensive compensation benchmark that simultaneously covers both static geometric and dynamic elastic deviations, thereby improving the positioning accuracy of the hoist across its entire stroke range.

[0051] Based on the above logic, the flexible correction operator at any given time satisfies the following relation: ; in, It is the moment of hoisting Flexible correction operator; It is the standard radius of the roll; It is the diameter of the wire rope; It is a moment The cumulative angular displacement of the drum; It is the flexibility constant of the wire rope; It is the moment of hoisting Equivalent quality; It is the gravitational acceleration of the hoist; It is a moment The suspension length of the wire rope; It is a floor function.

[0052] In this relation The effect of lever arm amplification caused by the increase of the radius of the drum with the number of rope layers is described, and geometric nonlinearity correction is achieved; This invention describes the strain deviation caused by the elastic elongation of a rope and achieves elastic nonlinear correction. Through the product coupling of two correction factors, this invention achieves a comprehensive evaluation of transmission errors under complex physical environments.

[0053] It should be further explained that the suspension length of the wire rope is dynamically updated based on the real-time height position of the cage on the hoist track. Specifically, for any given moment, the relative displacement of the cage is determined by multiplying the cumulative angular displacement of the drum by the standard radius, and then a differential calculation is performed using a preset initial well depth to calculate the suspension length of the wire rope in real time. This suspension length is always greater than zero. For high-position workstations, the suspension length is shorter, and the impact of strain deviation on displacement accuracy is smaller; for low-position workstations, the suspension length increases, and elastic deformation is significantly amplified. This invention further improves the accuracy of flexibility correction by introducing a real-time changing suspension length. (Compliance constant) Preferred Meters per Newton (m / N), which can be adjusted by the implementer based on the elastic modulus and cross-sectional area of ​​the wire rope: for lightweight hoists using high-strength polyethylene fiber ropes, the strength needs to be increased. to Meters per Newton (N) to compensate for greater elastic elongation; for heavy-duty cable hoists, this should be reduced. .

[0054] Thus, a flexible correction operator for correcting transmission deviations was obtained.

[0055] Step S400: Based on the equivalent mass, the flexible correction operator, and the reference acceleration of the hoist, determine the drive compensation amount; calculate the absolute deviation between the preset target displacement and the current displacement determined based on the cumulative angular displacement of the drum; use the ratio of the feedback speed determined based on the motor angular velocity to the absolute deviation as the damping constraint amount; use the difference between the drive compensation amount and the damping constraint amount as the control voltage and output it to the drive frequency converter to adjust the operation of the hoist.

[0056] It should be noted that when the hoist approaches the target stopping displacement, the low-frequency swaying and inertial overshoot caused by the rope flexibility are the core factors affecting stopping accuracy. This invention constructs a feedforward drive and position-sensitive damping coordinated output strategy by injecting the identified equivalent mass and a flexibility correction operator into the nonlinear control law, in order to absorb the residual energy from the dynamic source during the stopping phase.

[0057] First, the drive compensation amount of the hoist is calculated. It should be noted that due to the randomness of the cable load and the nonlinearity of the transmission ratio, a fixed control gain often leads to response lag or overshoot during start-up and shutdown. This invention constructs a feedforward channel based on real-time physical parameters, enabling the control voltage to pre-compensate for gravity loads and inertial resistance, thereby achieving dynamic decoupling between control commands and the power requirements of the actuator without relying on high-gain feedback.

[0058] Specifically, for any given moment, the sum of the equivalent mass and the gravitational acceleration of the hoist at that moment is extracted as the total static load. The reference acceleration at that moment is summed with the gravitational acceleration of the hoist, and then multiplied with the equivalent mass and the flexible correction operator at that moment. The flexible correction operator performs real-time gain compensation for the geometric lever arm drift and rope elastic strain in the power transmission path, thereby obtaining the physical feedforward component that characterizes the real-time driving force required under the current working condition.

[0059] Then, the damping constraint of the hoist is calculated. It should be noted that if the residual kinetic energy cannot be dissipated in time after the hoist enters the deceleration phase at high speed, it is prone to oscillation at the stopping point. This invention introduces a damping mechanism that adaptively enhances as the spatial distance shrinks. By nonlinearly correlating the feedback speed with the remaining travel, it ensures high response sensitivity of the hoist in the far-field stage, while forcibly generating strong braking in the near-field stage to achieve oscillation-free and accurate stopping.

[0060] Specifically, for any given moment, the absolute deviation between the target parking displacement and the current displacement at that moment is calculated as the denominator, and the feedback velocity at that moment is used as the numerator for division. By using a preset small value to avoid the denominator being singular, the damping constraint quantity that characterizes the rapid increase as the parking distance decreases is obtained.

[0061] Finally, the final drive control voltage is output. It should be noted that feedforward compensation solves the problem of accurate tracking, while position-sensitive damping solves the problem of stable stopping. This invention converts the torque demand in the dynamic domain into a drive command in the electrical domain through a voltage conversion coefficient, and uses a damping term to perform negative feedback regulation of the voltage, thereby achieving smooth acceleration and deceleration control throughout the entire process in complex flexible transmission environments.

[0062] Based on the above logic, the control voltage satisfies the following relationship: ; in, It is the moment of hoisting The control voltage; It is the moment of hoisting Equivalent quality; It is the moment of hoisting Flexible correction operator; It is the moment of hoisting Reference acceleration; It is the gravitational acceleration of the hoist; It is a moment The angular velocity of the motor; It is a moment The radius of the reel; It is the target displacement of the cage; It is the cage at all times The displacement; It is the voltage conversion factor; It is the damping strength coefficient; It is a preset microvalue used to prevent The value is 0, and the preferred value range is... ; It is the absolute value symbol. For feedback speed.

[0063] In this relation, the first term As an adaptive power feedforward term for the hoist, the controller can generate electromagnetic thrust in advance to counteract gravity and nonlinear lever arm deviation by utilizing the real-time characterization of variable load inertia by equivalent mass and the online compensation of transmission gain drift by a flexible correction operator. The core of constructing a position-sensitive variable-gain damped constraint lies in utilizing displacement deviation. The reciprocal of the value is used as the dynamic weight for velocity feedback. When the hoist cage enters the near-field parking area, the denominator contracts sharply, triggering a nonlinear increase in the damping coefficient, thereby forcibly dissipating the kinetic energy of the hoist and eliminating the low-frequency residual vibration caused by the flexibility of the rope.

[0064] It should be noted that the voltage conversion factor and damping strength coefficient The value needs to be set based on the inverter's response bandwidth and the hoist's operational stability: for sampling scenarios with drastic load changes and high requirements for dynamic tracking speed, the value needs to be increased. And decrease If we assume It is 0.08V / N. The value is set to 0.8 V·s to enhance the hoist's response sensitivity to acceleration commands; for heavy-duty conveying scenarios where cage vibration is significant and high requirements are placed on stable stopping, the value needs to be appropriately reduced. And increase If we assume It is 0.05V / N. The value is 1.5 V·s to improve the ability to suppress inertial overshoot. In this embodiment, The preferred value is 0.05V / N. The preferred value is 1.2 V·s; Furthermore, the reference acceleration is the ideal motion target preset by the controller for the hoist. It is obtained by performing function analysis or interpolation on a pre-built fifth-order polynomial or seven-segment S-shaped smooth curve at each sampling time. This curve is constructed based on physical constraints such as maximum acceleration and maximum jerk, and is used to provide the hoist with the theoretical dynamic acceleration command required to track the reference trajectory, thereby guiding the motor to generate the corresponding driving force.

[0065] Finally, the controller converts the calculated control voltage into a corresponding pulse frequency signal or analog voltage signal and sends it to the drive inverter. The drive inverter adjusts the output torque of the hoist drive motor, so that the hoist drives the cage and internal cable material to the target parking position according to the preset smooth curve.

[0066] like Figure 2 As shown in the figure, this is a dynamic response curve of the equivalent mass and the flexible correction operator. The solid line represents the equivalent mass, and the dashed line represents the flexible correction operator. From the graph, we can see that during the operation phase, as the load is applied and the wire rope winds, the solid line shows an upward or step-like trend, reflecting the dynamic evolution of the system's inertia. Correspondingly, the dashed line exhibits a clear cooperative following characteristic, adjusting synchronously with the increase of the equivalent mass. This indicates that the hoist can map and correct parameters in real time according to load changes to compensate for the elastic deformation of the wire rope and the deviation of the drum radius. When approaching the target position, both the solid and dashed lines tend to stabilize, without high-frequency fluctuations, reflecting the stability of the control logic during dynamic tracking and reducing the probability of load oscillation at the braking end.

[0067] This completes the adaptive smooth control output of the automatic hoist.

[0068] The second aspect of this embodiment provides a smooth acceleration and deceleration control system for an automatic hoist, such as... Figure 3 As shown, the automatic hoist smooth acceleration and deceleration control system includes a memory and a processor. The memory stores computer program instructions, and when the computer program instructions are executed by the processor, an automatic hoist smooth acceleration and deceleration control method according to the first aspect of the present invention is implemented.

[0069] The automatic hoist smooth acceleration and deceleration control system also includes other components well known to those skilled in the art, such as communication buses and communication interfaces. Their settings and functions are known in the art and will not be described in detail here.

[0070] In this invention, the aforementioned memory can be any tangible medium containing or storing a program that can be used or combined with an instruction execution system, apparatus, or device. For example, a computer-readable storage medium can be any suitable magnetic or magneto-optical storage medium, such as resistive random access memory (DRAM), dynamic random access memory (DRAM), static random access memory (SRAM), enhanced dynamic random access memory (DRAM), high-bandwidth memory, hybrid memory cube, etc., or any other medium that can be used to store desired information and can be accessed by an application, module, or both. Any such computer storage medium can be part of a device or accessible to or connected to a device.

[0071] The above are all preferred embodiments of the present invention and are not intended to limit the scope of protection of the present invention. Therefore, all equivalent changes made in accordance with the structure, shape and principle of the present invention should be covered within the scope of protection of the present invention.

Claims

1. A method for smooth acceleration and deceleration control of an automatic hoist, characterized in that, include: The synchronization data of the hoist is acquired to construct a synchronization data sequence, which includes the effective current of the drive motor, the cumulative angular displacement of the drum, and the angular velocity of the motor. The angular acceleration of the drive motor is calculated based on the motor angular velocity in the synchronous data sequence; the total drive torque of the drive motor is determined based on the effective current; the frictional resistance torque is determined based on the motor angular velocity and the preset friction model; the difference between the total drive torque and the frictional resistance torque is calculated; and the equivalent mass of the hoist is determined based on the ratio of the difference to the angular acceleration. The suspension length of the wire rope is calculated based on the cumulative angular displacement of the drum. The radius amplification ratio of the drum is determined based on the cumulative angular displacement of the drum, and the strain deviation ratio of the wire rope is determined based on the equivalent mass and suspension length. The radius amplification ratio and the strain deviation ratio are multiplied to obtain the flexible correction operator of the hoist. Based on the equivalent mass, the flexible correction operator, and the reference acceleration of the hoist, the drive compensation amount is determined; The absolute deviation between the preset target displacement and the current displacement determined based on the cumulative angular displacement of the drum is calculated. The ratio of the feedback speed determined based on the motor angular velocity to the absolute deviation is used as the damping constraint. The difference between the drive compensation and the damping constraint is used as the control voltage and output to the drive frequency converter to regulate the operation of the hoist.

2. The automatic hoist smooth acceleration and deceleration control method according to claim 1, characterized in that, The step of calculating the angular acceleration of the drive motor based on the motor angular velocity in the synchronization data sequence includes: The current time is any moment during the operation of the hoist; Calculate the difference between the motor angular velocity at the current moment and the motor angular velocity at the previous moment in the synchronous data sequence; The ratio of the difference to the preset sampling period is used as the angular acceleration of the drive motor at the current moment.

3. The automatic hoist smooth acceleration and deceleration control method according to claim 1, characterized in that, The step of determining the total driving torque of the drive motor based on the effective current and determining the frictional resistance torque based on the motor angular velocity and a preset friction model includes: Obtain the torque constant of the drive motor, and multiply the torque constant by the effective current to obtain the total drive torque of the drive motor; The viscous friction coefficient and static friction torque of the hoist are obtained. The viscous friction coefficient is multiplied by the motor angular velocity and then added to the static friction torque to obtain the friction resistance torque.

4. The automatic hoist smooth acceleration and deceleration control method according to claim 1, characterized in that, The method of determining the radius enlargement ratio of the drum based on the cumulative angular displacement of the drum includes: Obtain the standard radius of the drum and the diameter of the wire rope in the hoist; The cumulative angular position of the drum is removed by the single-turn radian value and rounded down to obtain the increment of the number of winding layers of the wire rope. Multiply the increase in the number of rope layers by the diameter of the wire rope, and then add it to the standard radius of the drum to obtain the equivalent radius of the drum. The ratio of the equivalent radius to the standard radius of the drum is used as the radius enlargement ratio of the drum.

5. The automatic hoist smooth acceleration and deceleration control method according to claim 1, characterized in that, The determination of the strain deviation ratio of the wire rope based on equivalent mass and suspension length includes: Obtain the gravitational acceleration of the hoist and the flexibility constant of the wire rope; Multiply the equivalent mass, gravitational acceleration, and flexibility constant of the hoist to obtain the rope elastic deviation. The suspension length is added to the rope elasticity deviation to obtain the equivalent suspension length, and the ratio of the equivalent suspension length to the suspension length is used as the strain deviation ratio.

6. The automatic hoist smooth acceleration and deceleration control method according to claim 1, characterized in that, The calculation of the suspension length of the wire rope based on the cumulative angular displacement of the drum includes: Obtain the preset initial suspension length and the standard radius of the drum; Multiply the cumulative angular displacement of the drum by the standard radius of the drum to obtain the winding displacement of the wire rope. The difference between the initial suspension length and the winding displacement of the wire rope is taken as the suspension length of the wire rope.

7. The automatic hoist smooth acceleration and deceleration control method according to claim 1, characterized in that, The determination of the drive compensation amount based on the equivalent mass, the flexible correction operator, and the reference acceleration of the hoist includes: Obtain the gravitational acceleration and voltage conversion coefficient of the hoist; The total reference acceleration is obtained by adding the reference acceleration of the hoist to the gravitational acceleration. The equivalent mass, flexible correction operator, total reference acceleration, and voltage conversion coefficient are multiplied together to obtain the drive compensation amount.

8. The automatic hoist smooth acceleration and deceleration control method according to claim 1, characterized in that, The acquisition of the damping constraint includes: Obtain the preset damping strength coefficient and the current radius of the drum; Multiply the motor angular velocity, the current radius of the drum, and the damping strength coefficient to obtain the equivalent damping speed; The ratio of the equivalent damping velocity to the absolute deviation is used as the damping constraint.

9. The automatic hoist smooth acceleration and deceleration control method according to claim 1, characterized in that, The acquisition of the effective current of the drive motor includes: Take any moment in the operation of the hoist as the current moment, and obtain the stator current of the drive motor at the current moment, the effective current at the previous moment, and the preset filter coefficient; The current weighted current is obtained by multiplying the stator current by a preset filter coefficient. The historical weighted current is obtained by multiplying the complement of the preset filter coefficients with the effective current at the previous moment. The current weighted current is added to the historical weighted current to obtain the effective current at the current moment.

10. A smooth acceleration and deceleration control system for an automatic hoist, characterized in that, The automatic hoist smooth acceleration and deceleration control system includes a processor and a memory. The memory stores computer program instructions, and when the computer program instructions are executed by the processor, an automatic hoist smooth acceleration and deceleration control method according to any one of claims 1-9 is implemented.

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