Tower crane frequency converter deviation correction control method and device, computing device and storage medium

Abstract

The embodiment of the application relates to the technical field of intelligent control, and relates to a deviation correction control method and device of a tower crane frequency converter, a computing device and a storage medium. The method specifically scheme is: obtaining encoder data generated by a tower crane motor when the tower crane motor operates at a set frequency; calculating an actual motor speed according to the encoder data, and calculating a deviation coefficient according to the actual motor speed and a rated motor speed; and performing deviation correction control on the frequency of the frequency converter according to the deviation coefficient. The embodiment of the application can dynamically obtain physical parameters of the tower crane, calculate a deviation coefficient according to the physical parameters, correct the frequency deviation of the frequency converter by using the deviation coefficient, and thus precisely control the operation of the tower crane, and ensure the accuracy of automatic operation of the tower crane.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of intelligent control, and in particular to a deviation correction control method and device for a tower crane frequency converter, a computing device and a storage medium. BACKGROUND

[0002] In the prior art, a tower crane is controlled manually to load goods, and the frequency of an output frequency converter is adjusted in real time according to a target position or the position of an obstacle. In this way, the deviation between the output frequency of the frequency converter and the running frequency of the motor cannot be detected. However, in automatic control, the tower crane runs completely according to a specified trajectory, and the position and speed of a fixed point in the process are calculated as fixed values. Since there is a deviation between the output frequency of the frequency converter and the running frequency of the motor, the safety and accuracy of the automatic trajectory running of the tower crane are seriously affected, and precise control of the running of the tower crane cannot be achieved. SUMMARY

[0003] In view of the above problems in the prior art, the present application provides a deviation correction control method and device for a tower crane frequency converter, a computing device and a storage medium, which can dynamically acquire physical parameters of a tower crane, calculate a deviation coefficient according to the physical parameters, correct the frequency deviation of the frequency converter by using the deviation coefficient, and implement precise control of the running of the tower crane, thereby ensuring the accuracy of the automatic running of the tower crane.

[0004] To achieve the above-mentioned purpose, the first aspect of the present application provides a deviation correction control method for a tower crane frequency converter, comprising:

[0005] acquiring encoder data generated when a motor of the tower crane runs at a set frequency;

[0006] calculating an actual motor speed according to the encoder data, and calculating a deviation coefficient according to the actual motor speed and a rated motor speed;

[0007] correcting the frequency of the frequency converter according to the deviation coefficient.

[0008] As a possible implementation manner of the first aspect, the calculation of the actual motor speed according to the encoder data comprises:

[0009] calculating the difference value of the values of the encoder in a selected interval according to the encoder data;

[0010] calculating the actual motor speed according to the difference value, the resolution of one revolution of the encoder, the sampling period and the speed ratio of the encoder to the motor.

[0011] As a possible implementation manner of the first aspect, the method further comprises:

[0012] in the sampling array of the encoder data, an interval with an index between a preset first value and a preset second value is intercepted as the selected interval.

[0013] As a possible implementation form of the first aspect, the calculating the deviation coefficient according to the motor actual speed and the motor rated speed comprises:

[0014] taking a ratio of the motor actual speed and the motor rated speed as the deviation coefficient.

[0015] As a possible implementation form of the first aspect, the deviation control of the frequency of the frequency converter according to the deviation coefficient further comprises:

[0016] monitoring an actual operation trajectory of the tower crane hook;

[0017] in a case where a deviation value between the actual operation trajectory and the planned trajectory is greater than a predetermined threshold, deviation controlling the frequency of the frequency converter.

[0018] As a possible implementation form of the first aspect, the deviation control of the frequency of the frequency converter according to the deviation coefficient comprises:

[0019] calculating an output frequency of the frequency converter according to the maximum speed of the tower crane hook and the deviation coefficient.

[0020] As a possible implementation form of the first aspect, the method further comprises:

[0021] calculating the maximum speed of the tower crane hook according to parameters of the tower crane motor, the frequency converter, the speed reducer and the encoder.

[0022] The second aspect of the present application provides a deviation control device of a tower crane frequency converter, comprising:

[0023] an acquisition unit configured to acquire encoder data generated by a tower crane motor when running at a set frequency;

[0024] a calculation unit configured to calculate a motor actual speed according to the encoder data, and calculate a deviation coefficient according to the motor actual speed and a motor rated speed;

[0025] a control unit configured to deviation control a frequency of a frequency converter according to the deviation coefficient.

[0026] As a possible implementation form of the second aspect, the calculation unit is configured to:

[0027] calculate a difference value of values of the encoder in a selected interval according to the encoder data;

[0028] calculate a motor actual speed according to the difference value, an encoder single-turn resolution, a sampling period, and a speed ratio of the encoder and the motor.

[0029] As a possible implementation manner of the second aspect, the computing unit is further configured to:

[0030] In the sampling array of the encoder data, an interval with an index between a preset first value and a preset second value is intercepted as the selected interval.

[0031] As a possible implementation manner of the second aspect, the computing unit is configured to:

[0032] The ratio of the actual speed of the motor and the rated speed of the motor is taken as the deviation coefficient.

[0033] As a possible implementation manner of the second aspect, the control unit is configured to:

[0034] monitoring an actual operation trajectory of a tower crane hook;

[0035] in a case where a deviation value between the actual operation trajectory and a planned trajectory is greater than a predetermined threshold, performing deviation correction control on a frequency of a frequency converter.

[0036] As a possible implementation manner of the second aspect, the control unit is configured to:

[0037] calculating an output frequency of the frequency converter according to a maximum speed of the tower crane hook and the deviation coefficient.

[0038] As a possible implementation manner of the second aspect, the control unit is further configured to:

[0039] calculating the maximum speed of the tower crane hook according to parameters of the tower crane motor, the frequency converter, a speed reducer and the encoder.

[0040] The third aspect of the present application provides a computing device, comprising:

[0041] a communication interface;

[0042] at least one processor connected with the communication interface; and

[0043] at least one memory connected with the processor and storing program instructions, the program instructions, when executed by the at least one processor, causing the at least one processor to perform the method of any of the first aspect.

[0044] The fourth aspect of the present application provides a computer readable storage medium, which stores program instructions, the program instructions, when executed by a computer, causing the computer to perform the method of any of the first aspect.

[0045] These and other aspects of the present application will become more fully understood from the following description of (several) embodiments, given by way of example only, and with reference to the accompanying drawings. BRIEF DESCRIPTION OF DRAWINGS

[0046] Various features and the relationship between various features of the present application will be further illustrated below with reference to the accompanying drawings. The drawings are all exemplary, some features are not shown in actual proportion, and some features in the drawings can omit features that are conventional in the field to which the present application pertains and are not essential to the present application, or additional features that are not essential to the present application can be shown, and the combination of various features shown in the drawings is not intended to limit the present application. In addition, throughout the specification, the same reference signs refer to the same contents. The specific drawings are as follows:

[0047] Figure 1 A schematic diagram of an embodiment of the tower crane frequency converter deviation correction control method provided by the embodiments of the present application;

[0048] Figure 2 A structural schematic diagram of an application scenario of an embodiment of the tower crane frequency converter deviation correction control method provided by the embodiments of the present application;

[0049] Figure 3 An encoder data schematic diagram of an embodiment of the tower crane frequency converter deviation correction control method provided by the embodiments of the present application;

[0050] Figure 4 An acquisition tower crane physical parameter and deviation correction principle diagram of an embodiment of the tower crane frequency converter deviation correction control method provided by the embodiments of the present application;

[0051] Figure 5 An effect diagram of an embodiment of the tower crane frequency converter deviation correction control method provided by the embodiments of the present application;

[0052] Figure 6 An effect diagram of an embodiment of the tower crane frequency converter deviation correction control method provided by the embodiments of the present application;

[0053] Figure 7 A schematic diagram of an embodiment of the tower crane frequency converter deviation correction device provided by the embodiments of the present application;

[0054] Figure 8 A schematic diagram of a computing device provided by the embodiments of the present application. DETAILED DESCRIPTION

[0055] The words "first, second, third, etc." or modules A, B, C, and the like in the specification and claims are only used to distinguish similar objects, and do not represent a specific order of the objects. It can be understood that the specific order or sequence can be interchanged as permitted, so that the embodiments of the present application described herein can be implemented in an order other than that illustrated or described herein.

[0056] In the following description, reference is made to the accompanying drawings which form a part hereof, and in which are shown by way of illustration specific embodiments in which the application can be practiced. The embodiments were chosen for purposes of illustration and description. Those of ordinary skill in the art, and with the benefit of this disclosure, will appreciate that there are many alternative ways that the methods and apparatuses taught herein can be implemented. Accordingly, the application is not intended to be limited.

[0057] The term "comprising" as used in the specification and claims includes that there are no other elements or steps. Thus, it should be interpreted as indicating the existence of the stated features, integers, steps or components as referred to, but not precluding the addition of one or more other features, integers, steps or components, or groups thereof. Thus, the expression "a device comprising elements A and B" should be interpreted to include other elements such as element C in addition to A and B. It will be understood that the terms "comprise", "comprises" or "comprising" when used in this specification and claims specifies the presence of stated features, integers, steps or components but does not preclude the presence or addition of one or more other features, integers, steps, components or groups thereof.

[0058] As used in the description of the application and the appended claims, the singular forms "a", "an" and "the" include plural referents unless the context clearly dictates otherwise. Thus, for example, reference to "a component" or "the component" can include a plurality of such components unless the context clearly indicates otherwise.

[0059] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application belongs. The terminology used in the description of the application herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the application. All publications, patent applications, patents, and other references mentioned in this specification are incorporated by reference in their entirety. In case of a conflict between the present specification and the incorporated references, the present specification will control. In addition, the terminology used in the description of the application herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the application. For the purposes of the present application, the following terms have the meanings indicated below:

[0060] 1) PLC (Programmable Logic Controller): Programmable logic controller is a digital operation electronic system specially designed for application in industrial environment. It uses a programmable memory to store instructions for performing logic operation, sequential control, timing, counting and arithmetic operation, etc. inside, and controls various types of mechanical equipment or production process through digital or analog input and output. Specifically, programmable logic controller is a digital operation controller with microprocessor for automatic control, which can load control instructions into memory for storage and execution at any time. Programmable controller is composed of CPU (Central Processing Unit), instruction and data memory, input / output interface, power supply, digital-analog conversion and other functional units. When the programmable logic controller is put into operation, its working process is generally divided into three stages, namely input sampling, user program execution and output refreshing three stages. Completing the above three stages is called a scanning cycle. During the entire running period, the CPU of programmable logic controller repeats the above three stages at a certain scanning speed.

[0061] 2) Variable-frequency Drive (VFD): is a power control device that applies variable frequency technology and microelectronic technology to control AC motor by changing the power frequency of motor working power supply. Variable-frequency drive is mainly composed of rectification (AC to DC), filtering, inversion (DC to AC), braking unit, driving unit, detection unit and micro processing unit, etc. Variable-frequency drive adjusts the voltage and frequency of output power supply by opening and closing internal IGBT (Insulated Gate Bipolar Transistor), provides the required power supply voltage for motor according to the actual needs of motor, and achieves the purpose of energy saving and speed regulation. In addition, variable-frequency drive has many protection functions, such as overcurrent, overvoltage and overload protection, etc.

[0062] 3) Software PLC: The so-called software PLC is to realize the control function of the traditional hardware PLC by using a general operating system and a PC (Personal Computer) as a software and hardware platform, that is, to encapsulate the control function of the PLC in software and run in a PC environment. Such a control system has the same functions as a hardware PLC while also having various advantages of a PC. The software PLC system is composed of a development system and a running system. The software PLC development system is actually a PLC programmer that integrates editing, debugging and compiling. The compiling part is the core of the development system. The features of the software PLC are as follows: retaining the PLC function, adopting a field bus network-oriented architecture, adopting an open communication interface such as an Ethernet and a high-speed serial port, adopting various relevant international industrial standards and a series of de facto standards, and realizing the function of the traditional PLC by using software.

[0063] The existing method will be introduced first, and then the technical solutions of the present application will be introduced in detail.

[0064] The traditional manual control of the tower crane loads the goods, and adjusts the frequency of the output frequency converter at any time according to the target position or the position of the obstacle. The manual control is adjusted at any time, and the deviation between the frequency output by the frequency converter and the running frequency of the motor cannot be perceived. However, in the automatic control operation, the fixed point position and the speed are calculated as the fixed values during the process. Since there is a deviation between the frequency output by the frequency converter and the running frequency of the motor, the safety and accuracy of the automatic trajectory operation of the tower crane are seriously affected, and the precise control of the tower crane operation cannot be realized.

[0065] The existing technology has the following defects: there is a deviation between the frequency output by the frequency converter and the running frequency of the motor, and the safety and accuracy of the automatic trajectory operation of the tower crane are poor.

[0066] Based on the technical problems existing in the above-mentioned prior art, the present application provides a tower crane frequency converter deviation correction control method and device, a computing device and a storage medium, which can dynamically obtain the physical parameters of the tower crane, calculate the deviation coefficient according to the physical parameters, correct the frequency deviation of the frequency converter by using the deviation coefficient, and implement precise control on the tower crane operation to ensure the accuracy of the automatic operation of the tower crane, thereby solving the technical problems of the existing technology, i.e., the deviation between the frequency output by the frequency converter and the running frequency of the motor, and the poor safety and accuracy of the automatic trajectory operation of the tower crane.

[0067] Figure 1 An embodiment of the tower crane frequency converter deviation correction control method provided by the present application is shown in the schematic diagram. As shown in the figure, the method can include: Figure 1

[0068] ​Step S110, obtaining encoder data generated by the tower crane motor when running at a set frequency;

[0069] Step S120, calculating the actual motor speed according to the encoder data, and calculating the deviation coefficient according to the actual motor speed and the rated motor speed;

[0070] Step S130, correcting the frequency of the frequency converter according to the deviation coefficient.

[0071] Figure 2 For an exemplary tower crane control system, it includes a video device, a controller, a frequency converter, a motor and an encoder.

[0072] The video device can be used to monitor the running trajectory of the tower crane hook. For example, the reference points in the process can be obtained by using the video device, and the reference points include the starting position of the tower crane hook, the target position and the passable position in front of the obstacle that should be avoided.

[0073] The motor is used to drive the movement of the tower crane hook. The tower crane includes several shafts, i.e. several adjustment directions. Each shaft is driven by a motor.

[0074] The frequency converter is used to receive the indication data output by the controller, and control the speed of the motor according to the indication data. One shaft direction corresponds to the use of one frequency converter for control.

[0075] The encoder is used to collect the actual position of the tower crane hook during movement, to help the tower crane hook avoid obstacles and reach the target position according to the planned trajectory.

[0076] The controller is used to generate a planned trajectory of the tower crane hook according to the reference points, and drive the frequency converter of the tower crane to control the hook to bypass the obstacles and accurately reach the target position according to the planned trajectory during the running of the hook.

[0077] During the operation of the tower crane, accurate control is a prerequisite for automatic and safe operation. Accurate control requires dynamic testing and correction of the physical parameters of the tower crane. The deviation correction control method of the tower crane frequency converter provided in the embodiments of the present application can be applied to the soft PLC control model of the tower crane controller. When the tower crane is working, the soft PLC control model is used to control the operation of the tower crane, the physical parameters of the tower crane are dynamically obtained, the frequency deviation is corrected, and the accurate operation effect is achieved.

[0078] The movement mechanism of the tower crane can include a slewing mechanism, a luffing mechanism and a hoisting mechanism. The slewing mechanism makes the heavy object move in a radius circle; the luffing mechanism makes the heavy object move horizontally in a straight line; and the hoisting mechanism makes the heavy object move vertically. The automatic control system of the tower crane includes three frequency converters, three encoders and three motors corresponding to the above-mentioned three mechanisms, which are respectively a tower crane jib slewing motor, a trolley luffing motor and a hook hoisting mechanism motor.

[0079] The control model dynamically obtains physical parameters in the automatic trajectory operation of the tower crane, and calculates the deviation coefficients corresponding to each motor respectively by using the physical parameters. Taking the deviation coefficient corresponding to the slewing motor as an example, the deviation correction control method of the tower crane frequency converter can include the following steps:

[0080] In step S110, the controller obtains the encoder data generated by the slewing motor when the slewing motor operates at the set frequency. For example, the slewing motor can be controlled to operate at 50Hz and 25Hz frequencies for 1 minute in advance, and the encoder data is recorded. The operation of recording the encoder data can be performed at a set time period, or can be performed when the tower crane is initially put into operation, after the tower crane jacking operation, after the fault maintenance, after a long-term shutdown, and during periodic calibration.

[0081] Figure 3 The encoder data schematic diagram of an embodiment of the deviation correction control method of the tower crane frequency converter provided by the embodiments of the present application is shown. In order to obtain the deviation coefficient corresponding to the slewing motor, the slewing motor is controlled to operate at a set frequency for a set time. Figure 3 The third column data in the table is the encoder data corresponding to the slewing motor. The third column data records the position of the tower crane hook in the slewing direction at each sampling time. Figure 3 The first column data and the second column data in the table are the encoder data corresponding to the luffing motor and the hoisting motor respectively. As shown in Figure 3 The positions of the tower crane hook in the luffing direction and the hoisting direction are unchanged.

[0082] The encoder arranged in the tower crane can record the movement distance of the load bearing rope. For example, the encoder value in the tower crane can record the angle of the load bearing rope wound on the drum. In the angle system, 360 parts of a circle are defined as 1 degree. Therefore, the number of turns of the load bearing rope wound on the drum and the movement distance of the load bearing rope can be further obtained by converting the encoder value. The encoder value can be the angle of the load bearing rope wound on the drum compared with the initial state. The initial state can be set according to system parameters. According to the structural design parameters of the tower crane and the recording accuracy of the encoder, the conversion relationship between the encoder value and the movement distance of the load bearing rope can be obtained. Further, the position, displacement and speed of the tower crane hook, and the actual speed of the motor can be obtained according to the encoder value.

[0083] In step S120, the controller first calculates the actual speed of the motor according to the encoder data, and then calculates the deviation coefficient according to the actual speed of the motor and the rated speed of the motor at the set frequency. For example, the ratio of the actual speed of the motor to the rated speed of the motor can be taken as the deviation coefficient.

[0084] During the operation of the hook, the controller drives the frequency converter of the tower crane. In an ideal state, the output frequency of the frequency converter indicated by the controller should be the same as the operating frequency of the motor. However, if there is a deviation between the output frequency of the frequency converter and the operating frequency of the motor, the safety and accuracy of the automatic trajectory operation of the tower crane will be seriously affected, and the precise control of the operation of the tower crane cannot be achieved. Similarly, in an ideal state, the actual speed of the motor at the set frequency should be the same as the rated speed of the motor. If there is a deviation between the actual speed of the motor and the rated speed of the motor, it means that the controller cannot achieve the precise control of the operation of the tower crane. Therefore, in the embodiments of the present application, the actual speed of the motor at the set frequency is first determined, and then the actual speed of the motor is compared with the rated speed of the motor at the frequency to obtain a deviation coefficient. The deviation coefficient also reflects the deviation between the output frequency of the frequency converter and the operating frequency of the motor.

[0085] In step S130, the controller can correct the deviation of the output frequency of the frequency converter according to the deviation coefficient, and send the frequency value after correction as indication data to the frequency converter. The frequency converter controls the speed of the motor according to the indication data, and then implements the operation control of the hook.

[0086] The above takes the deviation coefficient corresponding to the rotary motor as an example, obtains the encoder data, the rated speed of the motor and other physical parameters, and calculates the deviation coefficient corresponding to the rotary motor by using the physical parameters. Similarly, the same method can be used to calculate the deviation coefficients corresponding to the luffing motor and the hoisting motor. For example, taking the deviation coefficient corresponding to the luffing motor as an example, the deviation correction control method of the tower crane frequency converter can include the following steps:

[0087] In step S110, the encoder data generated by the luffing motor of the tower crane when operating at a set frequency is obtained.

[0088] In step S120, the actual speed of the luffing motor is calculated according to the encoder data, and the deviation coefficient is calculated according to the actual speed of the luffing motor and the rated speed of the luffing motor.

[0089] In step S130, the frequency of the frequency converter corresponding to the luffing motor is corrected according to the deviation coefficient.

[0090] In the case where there is a deviation between the output frequency of the frequency converter and the operating frequency of the motor, the deviation coefficient can be input to the control model of the controller to recalculate the output values of the hoisting motor frequency converter, the luffing motor frequency converter and the rotary motor frequency converter.

[0091] The embodiments of the present application can dynamically obtain the physical parameters of the tower crane, calculate the deviation coefficient according to the physical parameters, correct the frequency deviation of the frequency converter by using the deviation coefficient, and implement precise control of the operation of the tower crane to ensure the accuracy of the automatic operation of the tower crane.

[0092] In an embodiment, the calculating the actual motor speed from the encoder data comprises:

[0093] calculating the difference of the encoder values in the selected interval from the encoder data;

[0094] calculating the actual motor speed from the difference, the encoder resolution, the sampling period, the speed ratio of the encoder and the motor.

[0095] The encoder values can represent the actual position of the tower crane hook during movement. The difference of the encoder values can represent the displacement of the tower crane hook under the driving of the motor. The actual motor speed can be calculated from the difference of the encoder values, the encoder resolution, the sampling period, the speed ratio of the encoder and the motor, etc.

[0096] In an embodiment, the method further comprises:

[0097] In the sampling array of the encoder data, the interval with the index between the preset first value and the preset second value is selected as the selected interval.

[0098] In an example, the encoder data is input into a formula to calculate the deviation coefficient. The specific parameters and the formula are as follows:

[0099] The rated speed of the motor Ra=1300;

[0100] The encoder resolution Res=4096;

[0101] The sampling period Tsm=0.1;

[0102] The speed ratio of the encoder and the motor ratio: the value of the rotation direction ratio is 300; the value of the amplitude direction ratio is 50; the value of the lifting direction ratio is 7.5;

[0103] Formula (1): the length of the sampling array of the encoder data N=length(encoder_T);

[0104] Formula (2): the preset first value N1=fix(N*0.25);

[0105] Formula (3): the preset second value N2=fix(N*0.75);

[0106] Formula (4): the actual motor speed Hz_rpm=abs(diff(encoder_T(N1:N2))) / Res / Tsm*60*ratio;

[0107] Wherein, fix represents the rounding function; abs represents the absolute value function; the diff function performs the subtraction of the latter element from the former element; and "Tsm*60" is the time conversion of the sampling period by multiplying Tsm by 60s.

[0108] Wherein, the encoder data is stored in the sampling array. The data in the front 25% and the last 25% of the sampling array is cut off, and the middle part is reserved as the selected interval. The data in the front and the last of the sampling array corresponds to the data collected after the system starts and before it is turned off, and this part of data has poor stability. Therefore, after cutting off this part of data, the data in the selected interval is used for calculation, so that the accuracy of the final calculation result is higher and more reliable, and a better correction effect is achieved.

[0109] In an embodiment, the deviation coefficient is calculated according to the actual motor speed and the rated motor speed, comprising:

[0110] The ratio of the actual motor speed and the rated motor speed is taken as the deviation coefficient.

[0111] In one example, to further improve the accuracy of the calculation result, a plurality of actual motor speeds can be calculated based on a plurality of sampling periods, and then the average of the above plurality of actual motor speeds is taken. The ratio of the average of the actual motor speed and the rated motor speed is taken as the deviation coefficient. The specific parameters and formulas are as follows:

[0112] Formula (5): R = mean(Hz_rpm) / Ra

[0113] Wherein, R represents the deviation coefficient; the mean function is used to calculate the average; Hz_rpm represents the actual motor speed; and Ra represents the rated speed of the motor.

[0114] In an embodiment, the deviation coefficient is calculated according to the actual motor speed and the rated motor speed, comprising:

[0115] The actual running track of the tower crane hook is monitored;

[0116] In the case where the deviation value between the actual running track and the planned track is greater than a predetermined threshold, the frequency of the frequency converter is corrected.

[0117] When the actual track of the tower crane deviates from the normal planned track, the correction control method provided by the present application can be used to obtain the encoder data, and the deviation coefficient is calculated by the actual movement of the tower crane. The deviation coefficient can reflect the deviation between the actual running frequency and the output frequency of the frequency converter. The deviation coefficient is used for correction control to ensure the accuracy of automatic operation.

[0118] The application provides a deviation correction control method, which can be applied to the initial operation of a tower crane, tower crane jacking operation, fault maintenance, long-term operation and periodic calibration. The method can be used to obtain physical parameters in real time and calculate deviation coefficients. The deviation value of the actual operation trajectory and the planned trajectory can be compared with the predetermined threshold value, and the deviation can be automatically corrected or manually corrected when the deviation value exceeds the threshold value.

[0119] In an embodiment, the frequency of the frequency converter is controlled according to the deviation coefficient, including:

[0120] According to the maximum speed of the tower crane hook and the deviation coefficient, the output frequency of the frequency converter is calculated.

[0121] In an example, the formula for calculating the output frequency of the frequency converter is as follows:

[0122] 1) for the lifting mechanism, formula (6):

[0123] Lift.VFHz: = Lift.CmdVel * R * Lift.VFMaxHz / LIFT_HIGN_SPEED

[0124] Wherein, Lift.VFHz represents the output frequency of the frequency converter; Lift.CmdVel represents the planned speed; R represents the deviation coefficient; Lift.VFMaxHz represents the maximum frequency of the frequency converter; and LIFT_HIGN_SPEED represents the maximum speed of the tower crane hook.

[0125] 2) for the slewing mechanism, formula (7):

[0126] Turn.VFHz: = Turn.CmdVel * R * Turn.VFMaxHz / TURN_HIGN_SPEED

[0127] Wherein, Turn.VFHz represents the output frequency of the frequency converter; Turn.CmdVel represents the planned speed; R represents the deviation coefficient; Turn.VFMaxHz represents the maximum frequency of the frequency converter; and TURN_HIGN_SPEED represents the maximum speed of the tower crane hook.

[0128] 3) for the luffing mechanism, formula (8):

[0129] Swing.VFHz: = Swing.CmdVel * R * Swing.VFMaxHz / SWING_HIGN_SPEED

[0130] Swing. VFHz = Swing. CmdVel * R; (9) wherein Swing. VFHz represents the output frequency of the frequency converter; Swing. CmdVel represents the planned speed; R represents the deviation coefficient; Swing. VFMaxHz represents the maximum frequency of the frequency converter; and SWING HIGN SPEED represents the maximum speed of the tower crane hook.

[0131] The deviation coefficient R calculated in formula (5) can be input into the control model of the controller. In combination with the above physical parameters, the output values of the frequency converters of the hoisting motor, the luffing motor and the slewing motor are calculated in the control model by using formula (6), formula (7) and formula (8) respectively.

[0132] In an embodiment, the method further comprises:

[0133] The maximum speed of the tower crane hook is calculated according to the parameters of the tower crane motor, the frequency converter, the speed reducer and the encoder.

[0134] Specifically, the parameters of the motor, the frequency converter, the speed reducer and the encoder are input into the control model of the controller, and the maximum speed of the tower crane hook is calculated according to the above parameters. Taking the slewing mechanism as an example, the specific parameters and formula are as follows:

[0135] Turn. VFMaxRotateSpeed := 1300.0 / 60.0; (unit: rps, 1300 turns per 60s of the motor)

[0136] Turn. VFLapDistance := 2.0 * PI; (unit: radian)

[0137] Turn. VFGearRatio := (10.0 * 90.0 * 100.0 / 60.0); (10.0 and 90.0 are the speed reduction ratio, and 100 / 60 is the ratio of the slewing gear to the motor gear)

[0138] Formula (9): TURN HIGN SPEED := Turn. VFMaxRotateSpeed * Turn. VFLapDistance / Turn. VFGearRatio

[0139] wherein TURN HIGN SPEED represents the maximum speed of the tower crane hook; Turn. VFMaxRotateSpeed represents the maximum rotating speed of the motor; Turn. VFLapDistance represents the single-circle stroke of the encoder; and Turn. VFGearRatio represents the displacement ratio of the encoder and the motor.

[0140] Figure 4An embodiment of the tower crane variable frequency device deviation correction control method provided in the present application provides a tower crane physical parameter acquisition and deviation correction principle diagram. As shown in Figure 4 The embodiment of the tower crane variable frequency device deviation correction control method provided in the present application provides an effect diagram.

[0141] Figure 5 And Figure 6 The embodiment of the tower crane variable frequency device deviation correction control method provided in the present application provides an effect diagram. Figure 6 is an effect diagram after deviation correction processing. Figure 6 The curve in is both a planned trajectory of the hook and an actual running trajectory of the hook. After deviation correction processing, the two curves almost completely coincide to become a curve. In contrast, Figure 5 is an effect diagram without deviation correction processing. Figure 5 The smooth curve in is a planned trajectory of the hook. From Figure 5 As can be seen from the part marked by the black circle in, a small deviation is generated between the actual running trajectory of the hook and the planned trajectory, and the smoothness of the actual running trajectory is far inferior to that of the planned trajectory.

[0142] As shown in Figure 7 The present application also provides an embodiment of a tower crane variable frequency device deviation correction control device. The beneficial effects or technical problems solved by the device can be seen from the description of the corresponding method, or from the summary, which will not be repeated here.

[0143] In the embodiment of the tower crane variable frequency device deviation correction control device, the device comprises:

[0144] The acquisition unit 100 is configured to acquire encoder data generated by the tower crane motor when running at a set frequency;

[0145] The calculation unit 200 is configured to calculate the actual motor speed according to the encoder data, and calculate the deviation coefficient according to the actual motor speed and the rated motor speed;

[0146] The control unit 300 is configured to perform deviation correction control on the frequency of the variable frequency device according to the deviation coefficient.

[0147] In an embodiment, the calculation unit 200 is configured to:

[0148] According to the encoder data, a difference value of the encoder values in a selected interval is calculated;

[0149] According to the difference value, and the encoder single-turn resolution, the sampling period, the speed ratio of the encoder and the motor, the actual rotating speed of the motor is calculated.

[0150] In an embodiment, the calculation unit 200 is further configured to:

[0151] In the sampling array of the encoder data, an interval with the index between a preset first value and a preset second value is intercepted as the selected interval.

[0152] In an embodiment, the calculation unit 200 is configured to:

[0153] The ratio of the actual rotating speed of the motor and the rated rotating speed of the motor is taken as the deviation coefficient.

[0154] In an embodiment, the control unit 300 is configured to:

[0155] The actual running track of the tower crane hook is monitored;

[0156] In the case that the deviation value between the actual running track and the planned track is greater than a predetermined threshold, the frequency of the frequency converter is controlled for deviation correction.

[0157] In an embodiment, the control unit 300 is configured to:

[0158] According to the maximum speed of the tower crane hook and the deviation coefficient, the output frequency of the frequency converter is calculated.

[0159] In an embodiment, the control unit 300 is further configured to:

[0160] According to the parameters of the tower crane motor, the frequency converter, the speed reducer and the encoder, the maximum speed of the tower crane hook is calculated.

[0161] Figure 8 is a structural schematic diagram of a computing device 900 provided by an embodiment of the present application. The computing device 900 includes a processor 910, a memory 920, and a communication interface 930.

[0162] It should be understood that Figure 8 The communication interface 930 in the computing device 900 shown in the above embodiment can be used for communication between the computing device 900 and other devices.

[0163] The processor 910 can be connected with the memory 920. The memory 920 can be used to store the program code and data. Therefore, the memory 920 can be a storage unit inside the processor 910, can be an external storage unit independent of the processor 910, or can be a component including the storage unit inside the processor 910 and the external storage unit independent of the processor 910.

[0164] Optionally, the computing device 900 can further include a bus. The memory 920 and the communication interface 930 can be connected with the processor 910 through the bus. The bus can be a Peripheral Component Interconnect (PCI) bus or an Extended Industry Standard Architecture (EISA) bus, etc. The bus can be divided into an address bus, a data bus, a control bus, etc.

[0165] It should be understood that, in the embodiments of the present application, the processor 910 can be a central processing unit (CPU). The processor can also be other general-purpose processors, digital signal processors (DSP), Application specific integrated circuits (ASIC), field programmable gate arrays (FPGA) or other programmable logic devices, discrete gates or transistor logic, discrete hardware components, etc. The general-purpose processor can be a microprocessor or the processor can also be any conventional processor. Alternatively, the processor 910 can be one or more integrated circuits for executing relevant programs to implement the technical solutions provided by the embodiments of the present application.

[0166] The memory 920 can include read-only memory and random access memory, and provide instructions and data for the processor 910. A part of the processor 910 can also include a non-volatile random access memory. For example, the processor 910 can also store device type information.

[0167] When the computing device 900 is running, the processor 910 executes the computer execution instructions in the memory 920 to perform the operation steps of the above method.

[0168] It should be understood that the computing device 900 according to the embodiments of the present application can correspond to the respective subject performing the method according to the embodiments of the present application, and the above and other operations and / or functions of the respective modules in the computing device 900 are respectively for realizing the respective processes of the method according to the embodiments of the present application, and for brevity, will not be repeated here.

[0169] Those skilled in the art can clearly understand that the units and algorithm steps of each example described in combination with the embodiments disclosed herein can be realized in electronic hardware or a combination of computer software and electronic hardware. Whether the functions are realized in hardware or software depends on the specific application and design constraints of the technical solution. Those skilled in the art can use different methods to implement the described functions for each specific application, but such implementation should not be considered beyond the scope of the present application.

[0170] Those skilled in the art can clearly understand that, for the convenience and brevity of the description, the specific working processes of the above-described system, device and unit can refer to the corresponding processes in the foregoing method embodiments, which will not be repeated here.

[0171] In several embodiments provided in the present application, it should be understood that the disclosed system, device and method can be implemented in other ways. For example, the above-described device embodiments are only schematic, for example, the division of the units is only a logical function division, and actual implementation can have another division manner, for example, a plurality of units or components can be combined or integrated into another system, or some features can be ignored or not executed. In addition, the coupling or direct coupling or communication connection between the units shown or discussed can be indirect coupling or communication connection through some interface, device or unit, and can be electrical, mechanical or other forms.

[0172] The units described as separate components can or can not be physically separate, and the components shown as units can or can not be physical units, i.e., can be located in one place, or can be distributed on a plurality of network units. Part or all of the units can be selected according to actual needs to achieve the purpose of the embodiments.

[0173] In addition, each functional unit in each embodiment of the present application can be integrated in one processing unit, or each unit can be physically present separately, or two or more units can be integrated in one unit.

[0174] If the functions are implemented in the form of software function units and sold or used as independent products, they can be stored in a computer readable storage medium. Based on this understanding, the technical solutions of the present application essentially or the parts that make contributions to the prior art or parts of the technical solutions can be embodied in the form of a software product. The computer software product is stored in a storage medium and includes a plurality of instructions for causing a computer device (which can be a personal computer, a server, or a network device, etc.) to execute all or part of the steps of the methods described in the various embodiments of the present application. The aforementioned storage medium includes: a U disk, a mobile hard disk, a read-only memory (ROM), a random access memory (RAM), a magnetic disk or an optical disk, and various program code storage media.

[0175] The embodiments of the present application also provide a computer readable storage medium, which stores a computer program. The program is executed by a processor to perform a diversified problem generation method. The method includes at least one of the schemes described in the above embodiments.

[0176] The computer storage medium of the embodiments of the present application can adopt any combination of one or more computer readable media. The computer readable medium can be a computer readable signal medium or a computer readable storage medium. The computer readable storage medium can be, but is not limited to, an electrical, magnetic, optical, electromagnetic, infrared, or semiconductor system, device or apparatus, or any combination thereof. More specific examples (non-exhaustive list) of the computer readable storage medium include: an electrical connection having one or more wires, a portable computer diskette, a hard disk, a random access memory (RAM), a read-only memory (ROM), an erasable programmable read-only memory (EPROM or flash memory), an optical fiber, a portable compact disk read-only memory (CD-ROM), an optical storage device, a magnetic storage device, or any suitable combination of the above. In this document, the computer readable storage medium can be any tangible medium that contains or stores a program that can be used by or in conjunction with an instruction execution system, device or apparatus.

[0177] The computer readable signal medium can include a data signal propagated in a baseband or as a part of a carrier wave, in which a computer readable program code is borne. Such a propagated data signal can take various forms, including but not limited to an electromagnetic signal, an optical signal or any suitable combination thereof. The computer readable signal medium can also be any computer readable medium other than the computer readable storage medium, which can send, propagate or transmit a program for use by or in conjunction with an instruction execution system, device or apparatus.

[0178] The computer readable media on which the program code can be carried by any suitable medium, including but not limited to wireless, wired, optical fiber cable, RF, and the like, or any suitable combination of the foregoing.

[0179] Computer program code for carrying out operations of the present application can be written in any combination of one or more programming languages, including an object oriented programming language such as Java, Smalltalk, C++ or the like and conventional procedural programming languages, such as the "C" programming language or similar programming languages. The program code can execute entirely on the user's computer, partly on the user's computer, as a stand-alone software package, partly on the user's computer and partly on a remote computer or entirely on the remote computer or server. In the latter scenario, the remote computer can be connected to the user's computer through any type of network, including a local area network (LAN) or a wide area network (WAN), or the connection can be made to an external computer (for example, through the Internet using an Internet Service Provider).

[0180] Note that the above merely provides the preferred embodiments of the present application and the applied technical principles. It is understood by those skilled in the art that the present application is not limited to the specific embodiments described herein, and various obvious changes, re-adjustments and substitutions can be made by those skilled in the art without departing from the scope of the present application. Therefore, although the present application has been described in detail through the above embodiments, the present application is not limited to the above embodiments, and more other equivalent embodiments can be included without departing from the concept of the present application, and all belong to the protection scope of the present application.

Claims

1. A method for correcting deviations in a tower crane frequency converter, characterized in that, include: Acquire encoder data generated by the tower crane motor when it is running at a set frequency; The actual motor speed is calculated based on the encoder data, and the deviation coefficient is calculated based on the actual motor speed and the rated motor speed. Based on the aforementioned deviation coefficient, the frequency of the inverter is controlled to correct the deviation. The step of calculating the actual motor speed based on the encoder data includes: calculating the difference between encoder values ​​within a selected interval based on the encoder data; calculating the actual motor speed based on the difference, encoder single-turn resolution, sampling period, and encoder-motor speed ratio; wherein, in the sampling array of the encoder data, the interval between a preset first value and a preset second value is extracted as the selected interval. The step of calculating the deviation coefficient based on the actual speed of the motor and the rated speed of the motor includes: using the ratio of the actual speed of the motor to the rated speed of the motor as the deviation coefficient; The step of correcting the frequency of the frequency converter based on the deviation coefficient includes: calculating the output frequency of the frequency converter based on the maximum speed of the tower crane hook and the deviation coefficient; wherein the maximum speed of the tower crane hook is calculated based on the parameters of the tower crane motor, the frequency converter, the reducer, and the encoder.

2. The method according to claim 1, characterized in that, The step of correcting the frequency of the inverter based on the deviation coefficient further includes: Monitor the actual operating trajectory of the tower crane hook; If the deviation between the actual operating trajectory and the planned trajectory is greater than a predetermined threshold, the frequency of the inverter is controlled to correct the deviation.

3. A correction control device for a tower crane frequency converter, characterized in that, include: The acquisition unit is used to acquire encoder data generated by the tower crane motor when it is running at a set frequency. A calculation unit is used to calculate the actual motor speed based on the encoder data, and to calculate a deviation coefficient based on the actual motor speed and the rated motor speed. The calculation of the actual motor speed based on the encoder data includes: calculating the difference between encoder values ​​within a selected interval based on the encoder data; calculating the actual motor speed based on the difference, the encoder single-turn resolution, the sampling period, and the speed ratio between the encoder and the motor. The selected interval is defined as the interval between a preset first value and a preset second value in the sampled array of the encoder data. The calculation of the deviation coefficient based on the actual motor speed and the rated motor speed includes: using the ratio of the actual motor speed to the rated motor speed as the deviation coefficient. A control unit is used to perform frequency correction control on the frequency converter according to the deviation coefficient; wherein, the frequency correction control on the frequency converter according to the deviation coefficient includes: calculating the output frequency of the frequency converter according to the maximum speed of the tower crane hook and the deviation coefficient; wherein, the maximum speed of the tower crane hook is calculated according to the parameters of the tower crane motor, the frequency converter, the reducer, and the encoder.

4. A computing device, characterized in that, include: Communication interface; At least one processor connected to the communication interface; as well as At least one memory connected to the processor and storing program instructions that, when executed by the at least one processor, cause the at least one processor to perform the method of claim 1 or 2.

5. A computer-readable storage medium having program instructions stored thereon, characterized in that, When the program instructions are executed by a computer, the computer performs the method of claim 1 or 2.

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