Jacking transfer machine and motor rotating speed control method and device thereof

Abstract

The invention relates to the technical field of jacking transfer machines, and provides a jacking transfer machine and a motor rotating speed control method and device.The jacking transfer machine comprises a rotating shaft, a cam arranged on the rotating shaft and a motor driving the rotating shaft, and an elastic buffer layer is arranged between the cam and a jacked object; the method comprises the following steps: detecting a displacement signal of the jacked object; acquiring a feedback rotating speed signal of the motor according to the displacement signal; performing band-pass filtering on the feedback rotating speed signal, and calculating an elastic calibration value according to the filtered signal; and when FOC control is carried out on the rotating speed of the motor, a given current parameter is calibrated according to the elastic calibration value, so that calibration of the rotating speed of the motor and calibration of the displacement of the jacked object are achieved. According to the invention, the influence of the elastic buffer layer on the jacking displacement can be effectively reduced, and the controllable precision of the jacking displacement is improved.

Description

Technical Field

[0001] This invention relates to the field of lifting and transferring machine technology, specifically to a lifting and transferring machine and its motor speed control method and device. Background Technology

[0002] Lifting and transferring machines are common devices on conveyor lines, with cam-based lifting structures being particularly prevalent. Related technologies often employ an elastic buffer layer, such as a polyurethane gasket, between the cam and the object being lifted to effectively reduce impact and wear. However, the presence of this elastic buffer layer can cause elastic vibrations in the object being lifted, resulting in an error between the cam's output lifting stroke and the actual displacement of the object. Furthermore, this error varies with the load, making calibration difficult. Summary of the Invention

[0003] To solve the above-mentioned technical problems, the present invention provides a lifting and transferring machine and its motor speed control method and device, which can calibrate the displacement of the lifted object by calibrating the motor speed, thereby effectively reducing the influence of the elastic buffer layer on the lifting displacement and improving the controllability accuracy of the lifting displacement.

[0004] The technical solution adopted in this invention is as follows:

[0005] A method for controlling the motor speed of a lifting and transferring machine, the lifting and transferring machine including a rotating shaft, a cam disposed on the rotating shaft, and a motor driving the rotating shaft, wherein an elastic buffer layer is disposed between the cam and the object being lifted, the method comprising the following steps: detecting the displacement signal of the object being lifted; obtaining a feedback speed signal of the motor based on the displacement signal; performing bandpass filtering on the feedback speed signal and calculating an elastic calibration value based on the filtered signal; and calibrating a given current parameter with the elastic calibration value when performing FOC (Field-Oriented Control) control on the motor speed, so as to achieve calibration of the motor speed and calibration of the displacement of the object being lifted.

[0006] The feedback speed signal is:

[0007]

[0008] Wherein, n represents the feedback speed signal, I is the ratio of the motor speed to the cam speed, f(S) represents the expression of the theoretical lifting displacement S of the cam with respect to the rotation angle of the cam, and d / dt represents the derivative with respect to time t.

[0009] The feedback speed signal is bandpass filtered, and the elastic calibration value is calculated based on the filtered signal, specifically including:

[0010] The filtered signal is obtained after passing through the bandpass filter:

[0011]

[0012] Where y represents the filtered signal, which is a function of time t, and ω HP ω is the lower passband limit of the bandpass filter. LP τ is the upper passband limit of the bandpass filter, τ is the integration time variable, and n(τ) represents the value of the feedback speed signal at τ.

[0013] The elastic calibration value is calculated based on the filtered signal:

[0014] i cal =α·y

[0015] Among them, i cal The elastic calibration value is given, and α is the current-to-speed ratio coefficient.

[0016] When performing FOC control on the motor speed, the given current parameter is calibrated using the elastic calibration value. Specifically, this includes: acquiring the command speed signal of the motor; obtaining the initial q-axis command current through PI control based on the command speed signal and the feedback speed signal; and subtracting the elastic calibration value from the initial q-axis command current to obtain the calibrated q-axis command current.

[0017] The motor speed control method for the lifting and transferring machine further includes: providing a d-axis command current; acquiring the actual three-phase current of the motor; converting the actual three-phase current into a d-axis feedback current and a q-axis feedback current; and performing SVPWM (Space Vector Pulse Width Modulation) control on the motor based on the calibrated q-axis command current, the q-axis feedback current, the d-axis command current, and the d-axis feedback current.

[0018] A motor speed control device for a lifting and transferring machine, the lifting and transferring machine including a rotating shaft, a cam mounted on the rotating shaft, and a motor driving the rotating shaft, wherein an elastic buffer layer is provided between the cam and the object being lifted, the device including: a detection module for detecting the displacement signal of the object being lifted; an acquisition module for acquiring a feedback speed signal of the motor based on the displacement signal; a calculation module for bandpass filtering the feedback speed signal and calculating an elastic calibration value based on the filtered signal; and a calibration module for calibrating a given current parameter using the elastic calibration value when performing FOC control on the motor speed, thereby achieving calibration of the motor speed and calibration of the displacement of the object being lifted.

[0019] The feedback speed signal is:

[0020]

[0021] Wherein, n represents the feedback speed signal, I is the ratio of the motor speed to the cam speed, f(S) represents the expression of the theoretical lifting displacement S of the cam with respect to the rotation angle of the cam, and d / dt represents the derivative with respect to time t.

[0022] The calculation module is specifically used for:

[0023] The filtered signal is obtained after passing through the bandpass filter:

[0024]

[0025] Where y represents the filtered signal, which is a function of time t, and ω HP ω is the lower passband limit of the bandpass filter. LP τ is the upper passband limit of the bandpass filter, τ is the integration time variable, and n(τ) represents the value of the feedback speed signal at τ.

[0026] The elastic calibration value is calculated based on the filtered signal:

[0027] i cal =α·y

[0028] Among them, i cal The elastic calibration value is given, and α is the current-to-speed ratio coefficient.

[0029] The calibration module is specifically used for: acquiring the command speed signal of the motor; obtaining the initial q-axis command current through PI control based on the command speed signal and the feedback speed signal; and subtracting the elastic calibration value from the initial q-axis command current to obtain the calibrated q-axis command current.

[0030] A lifting and transferring machine includes a motor speed control device for the lifting and transferring machine.

[0031] The beneficial effects of this invention are:

[0032] This invention obtains the feedback speed signal of the motor by detecting the displacement signal of the object being lifted, calculates the elastic calibration value based on the filtered feedback speed signal, and calibrates the given current parameter in the motor speed control with the elastic calibration value. Thus, by calibrating the motor speed, the displacement of the object being lifted can be calibrated, thereby effectively reducing the influence of the elastic buffer layer on the lifting displacement and improving the controllability of the lifting displacement. Attached Figure Description

[0033] Figure 1 This is a schematic diagram of the structure of a lifting and transferring machine according to an embodiment of the present invention;

[0034] Figure 2 This is a flowchart of the motor speed control method for a lifting and transferring machine according to an embodiment of the present invention;

[0035] Figure 3 This is a flowchart of the motor speed FOC control process according to an embodiment of the present invention;

[0036] Figure 4 This is a block diagram of the motor speed control device of the lifting and transferring machine according to an embodiment of the present invention. Detailed Implementation

[0037] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0038] like Figure 1 As shown, a lifting and transferring machine according to an embodiment of the present invention may include a rotating shaft 1, a cam 2 disposed on the rotating shaft 1, and a motor 3 driving the rotating shaft 1. An elastic buffer layer is provided between the cam and the object being lifted. This elastic buffer layer may be a polyurethane gasket or the like, which can effectively reduce the impact and wear on the cam and the object being lifted.

[0039] like Figure 2 As shown, the motor speed control method of the lifting and transferring machine according to an embodiment of the present invention includes the following steps:

[0040] S1 detects the displacement signal of the object being lifted.

[0041] In one embodiment of the present invention, the displacement signal of the object being lifted can be obtained in real time by a displacement sensor.

[0042] S2, obtain the motor's feedback speed signal based on the displacement signal.

[0043] In one embodiment of the present invention, the feedback speed signal is:

[0044]

[0045] Where n represents the feedback speed signal, which is a time-domain signal; I is the ratio of the motor speed to the cam speed; f(S) represents the expression for the theoretical lifting displacement S of the cam with respect to the cam's rotation angle; and d / dt represents the derivative with respect to time t. f(S) belongs to known cam curve data. For example, when designing, manufacturing, or purchasing a cam, the relationship between its rotation angle θ and the theoretical lifting displacement S is known as θ = f(S). It should be understood that this feedback speed signal n does not represent the actual speed data of the motor, but rather the speed data calculated based on the displacement detection.

[0046] S3 performs bandpass filtering on the feedback speed signal and calculates the elastic calibration value based on the filtered signal.

[0047] Specifically, the filtered signal is obtained after passing through a bandpass filter:

[0048]

[0049] Where y represents the filtered signal, which is a function of time t, and ω HP ω is the lower passband limit of the bandpass filter. LP τ is the upper passband limit of the bandpass filter, τ is the integration time variable, and n(τ) represents the value of the feedback speed signal at τ.

[0050] In this embodiment of the invention, correlation processing is performed directly based on the time-domain signal of rotational speed, which can meet the real-time requirements.

[0051] The elastic calibration value is calculated based on the filtered signal:

[0052] i cal =α·y

[0053] Among them, i cal The value is a flexible calibration value, where α is the current-to-speed ratio coefficient, which is preset and set manually based on experience. The order of magnitude of α is determined by i. cal The unit of y is determined by the unit of y. In a specific embodiment of the present invention, i cal The units for y and y can be A (amperes) and r / s (revolutions per second), respectively.

[0054] S4, when performing FOC control on the motor speed, calibrates the given current parameter with an elastic calibration value to achieve calibration of the motor speed and the displacement of the lifted object.

[0055] The motor speed FOC control flow of one embodiment of the present invention is as follows: Figure 3 As shown, the command speed signal n of the motor can be obtained. ref Then, based on the command speed signal n ref The initial q-axis command current iq is obtained through PI control, based on the feedback speed signal n.0ref With the initial q-axis command current iq 0ref Subtract the elastic calibration value i cal The calibrated q-axis command current iq is obtained. ref Simultaneously, the d-axis command current id can be given. ref For example, it can be set to 0, and the actual three-phase current of the motor can be collected, transforming the actual three-phase current into d-axis feedback current id and q-axis feedback current iq. Finally, based on the calibrated q-axis command current iq... ref q-axis feedback current iq, d-axis command current id ref The d-axis feedback current id is used to perform SVPWM control on the motor. Thus, by converting the speed of the vibration under the elastic buffer into a calibration parameter, the q-axis current is calibrated, thereby calibrating the motor speed and ultimately the displacement of the lifted object.

[0056] According to the embodiment of the present invention, the motor speed control method of the lifting transfer machine obtains the feedback speed signal of the motor by detecting the displacement signal of the object being lifted, calculates the elastic calibration value based on the filtered feedback speed signal, and calibrates the given current parameter in the motor speed control with the elastic calibration value. Thus, by calibrating the motor speed, the displacement of the object being lifted can be calibrated, thereby effectively reducing the influence of the elastic buffer layer on the lifting displacement and improving the controllability accuracy of the lifting displacement.

[0057] Corresponding to the motor speed control method of the lifting and transferring machine in the above embodiments, the present invention also proposes a motor speed control device for the lifting and transferring machine.

[0058] like Figure 4 As shown, the motor speed control device of the lifting and transferring machine according to an embodiment of the present invention includes a detection module 10, an acquisition module 20, a calculation module 30, and a calibration module 40. The detection module 10 is used to detect the displacement signal of the object being lifted; the acquisition module 20 is used to acquire the feedback speed signal of the motor based on the displacement signal; the calculation module 30 is used to perform bandpass filtering on the feedback speed signal and calculate an elastic calibration value based on the filtered signal; the calibration module 40 is used to calibrate the given current parameter with the elastic calibration value when performing FOC control on the motor speed, so as to achieve calibration of the motor speed and calibration of the displacement of the object being lifted.

[0059] In one embodiment of the present invention, the detection module 10 includes a displacement sensor, which can detect the displacement signal of the object being lifted in real time.

[0060] In one embodiment of the present invention, the feedback speed signal is:

[0061]

[0062] Where n represents the feedback speed signal, which is a time-domain signal; I is the ratio of the motor speed to the cam speed; f(S) represents the expression for the theoretical lifting displacement S of the cam with respect to the cam's rotation angle; and d / dt represents the derivative with respect to time t. f(S) belongs to known cam curve data. For example, when designing, manufacturing, or purchasing a cam, the relationship between its rotation angle θ and the theoretical lifting displacement S is known as θ = f(S). It should be understood that this feedback speed signal n does not represent the actual speed data of the motor, but rather the speed data calculated based on the displacement detection.

[0063] The calculation module 30 specifically obtains the filtered signal through a bandpass filter:

[0064]

[0065] Where y represents the filtered signal, which is a function of time t, and ω HP ω is the lower passband limit of the bandpass filter. LP τ is the upper passband limit of the bandpass filter, τ is the integration time variable, and n(τ) represents the value of the feedback speed signal at τ.

[0066] In this embodiment of the invention, correlation processing is performed directly based on the time-domain signal of rotational speed, which can meet the real-time requirements.

[0067] Then, the calculation module 30 can calculate the elastic calibration value based on the filtered signal:

[0068] i cal =α·y

[0069] Among them, i cal The value is a flexible calibration value, where α is the current-to-speed ratio coefficient, which is preset and set manually based on experience. The order of magnitude of α is determined by i. cal The unit of y is determined by the unit of y. In a specific embodiment of the present invention, i cal The units for y and y can be A (amperes) and r / s (revolutions per second), respectively.

[0070] The motor speed FOC control flow of one embodiment of the present invention is as follows: Figure 3 As shown, the calibration module 40 can acquire the command speed signal n of the motor. ref Then, based on the command speed signal n ref The initial q-axis command current iq is obtained through PI control, based on the feedback speed signal n. 0ref With the initial q-axis command current iq 0ref Subtract the elastic calibration value i cal The calibrated q-axis command current iq is obtained. ref Simultaneously, the d-axis command current id can be given. refFor example, it can be set to 0, and the actual three-phase current of the motor can be collected, transforming the actual three-phase current into d-axis feedback current id and q-axis feedback current iq. Finally, based on the calibrated q-axis command current iq... ref q-axis feedback current iq, d-axis command current id ref The d-axis feedback current id is used to perform SVPWM control on the motor. Thus, by converting the speed of the vibration under the elastic buffer into a calibration parameter, the q-axis current is calibrated, thereby calibrating the motor speed and ultimately the displacement of the lifted object.

[0071] According to an embodiment of the present invention, the motor speed control device of the lifting transfer machine obtains the feedback speed signal of the motor by detecting the displacement signal of the object being lifted, calculates the elastic calibration value based on the filtered feedback speed signal, and calibrates the given current parameter in the motor speed control with the elastic calibration value. Thus, by calibrating the motor speed, the displacement of the object being lifted can be calibrated, thereby effectively reducing the influence of the elastic buffer layer on the lifting displacement and improving the controllability accuracy of the lifting displacement.

[0072] Based on the motor speed control device of the lifting and transferring machine in the above embodiments, the present invention also proposes a lifting and transferring machine.

[0073] The specific implementation of the lifting and transferring machine in this invention can be referred to the above embodiments, and will not be repeated here.

[0074] According to the embodiments of the present invention, the lifting and transferring machine can calibrate the displacement of the object being lifted by calibrating the motor speed, thereby effectively reducing the influence of the elastic buffer layer on the lifting displacement and improving the controllability of the lifting displacement.

[0075] In the description of this invention, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of indicated technical features. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of that feature. "A plurality of" means two or more, unless otherwise explicitly specified.

[0076] In this invention, unless otherwise explicitly specified and limited, the terms "installation," "connection," "linking," and "fixing," etc., should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication of two components or the interaction between two components. Those skilled in the art can understand the specific meaning of the above terms in this invention according to the specific circumstances.

[0077] In this invention, unless otherwise explicitly specified and limited, "above" or "below" the second feature can mean that the first feature is in direct contact with the second feature, or that the first feature is in indirect contact with the second feature through an intermediate medium. Furthermore, "above," "over," and "on top" of the second feature can mean that the first feature is directly above or diagonally above the second feature, or simply that the first feature is at a higher horizontal level than the second feature. "Below," "below," and "under" the second feature can mean that the first feature is directly below or diagonally below the second feature, or simply that the first feature is at a lower horizontal level than the second feature.

[0078] In the description of this specification, the references to terms such as "one embodiment," "some embodiments," "example," "specific example," or "some examples," etc., indicate that a specific feature, structure, material, or characteristic described in connection with that embodiment or example is included in at least one embodiment or example of the present invention. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples. Furthermore, without contradiction, those skilled in the art can combine and integrate the different embodiments or examples described in this specification, as well as the features of different embodiments or examples.

[0079] Any process or method description in the flowchart or otherwise herein can be understood as representing a module, segment, or portion of code comprising one or more executable instructions for implementing a particular logical function or process, and the scope of the preferred embodiments of the invention includes additional implementations in which functions may be performed not in the order shown or discussed, including substantially simultaneously or in reverse order depending on the functions involved, as will be understood by those skilled in the art to which embodiments of the invention pertain.

[0080] The logic and / or steps represented in the flowchart or otherwise described herein, for example, can be considered as a ordered list of executable instructions for implementing logical functions, and can be embodied in any computer-readable medium for use by, or in conjunction with, an instruction execution system, apparatus, or device (such as a computer-based system, a processor-included system, or other system that can fetch and execute instructions from, an instruction execution system, apparatus, or device). For the purposes of this specification, "computer-readable medium" can be any means that can contain, store, communicate, propagate, or transmit programs for use by, or in conjunction with, an instruction execution system, apparatus, or device. More specific examples (a non-exhaustive list) of computer-readable media include: an electrical connection having one or more wires (electronic device), a portable computer disk drive (magnetic device), random access memory (RAM), read-only memory (ROM), erasable and editable read-only memory (EPROM or flash memory), fiber optic devices, and portable optical disc read-only memory (CDROM). Alternatively, the computer-readable medium may be paper or other suitable media on which the program can be printed, since the program can be obtained electronically, for example, by optically scanning the paper or other medium, followed by editing, interpreting, or otherwise processing as necessary, and then stored in a computer memory.

[0081] It should be understood that various parts of the present invention can be implemented in hardware, software, firmware, or a combination thereof. In the above embodiments, multiple steps or methods can be implemented in software or firmware stored in memory and executed by a suitable instruction execution system. For example, if implemented in hardware, as in another embodiment, it can be implemented using any one or a combination of the following techniques known in the art: discrete logic circuits having logic gates for implementing logical functions on data signals, application-specific integrated circuits (ASICs) having suitable combinational logic gates, programmable gate arrays (PGAs), field-programmable gate arrays (FPGAs), etc.

[0082] Those skilled in the art will understand that all or part of the steps of the methods described in the above embodiments can be implemented by a program instructing related hardware. The program can be stored in a computer-readable storage medium, and when executed, it includes one or a combination of the steps of the method embodiments.

[0083] Furthermore, the functional units in the various embodiments of the present invention can be integrated into a processing module, or each unit can exist physically separately, or two or more units can be integrated into a module. The integrated module can be implemented in hardware or as a software functional module. If the integrated module is implemented as a software functional module and sold or used as an independent product, it can also be stored in a computer-readable storage medium.

[0084] Although embodiments of the present invention have been shown and described above, it is understood that the above embodiments are exemplary and should not be construed as limiting the present invention. Those skilled in the art can make changes, modifications, substitutions and variations to the above embodiments within the scope of the present invention.

Claims

1. A method for controlling the motor speed of a lifting and transferring machine, characterized in that, The lifting and transferring machine includes a rotating shaft, a cam mounted on the rotating shaft, and a motor that drives the rotating shaft. An elastic buffer layer is provided between the cam and the object being lifted. The method includes the following steps: Detect the displacement signal of the object being lifted; The feedback speed signal of the motor is obtained based on the displacement signal; The feedback speed signal is bandpass filtered, and the elastic calibration value is calculated based on the filtered signal. When performing FOC control on the motor speed, the given current parameter is calibrated using the elastic calibration value to achieve calibration of the motor speed and the displacement of the lifted object.

2. The motor speed control method for the lifting and transferring machine according to claim 1, characterized in that, The feedback speed signal is: Wherein, n represents the feedback speed signal, I is the ratio of the motor speed to the cam speed, f(S) represents the expression of the theoretical lifting displacement S of the cam with respect to the rotation angle of the cam, and d / dt represents the derivative with respect to time t.

3. The motor speed control method for the lifting and transferring machine according to claim 1, characterized in that, The feedback speed signal is bandpass filtered, and the elastic calibration value is calculated based on the filtered signal, specifically including: The filtered signal is obtained after passing through the bandpass filter: Where y represents the filtered signal, which is a function of time t, and ω HP ω is the lower passband limit of the bandpass filter. LP τ is the upper passband limit of the bandpass filter, τ is the integration time variable, and n(τ) represents the value of the feedback speed signal at τ. The elastic calibration value is calculated based on the filtered signal: i cal =α·y Among them, i cal The elastic calibration value is given, and α is the current-to-speed ratio coefficient.

4. The motor speed control method for the lifting and transferring machine according to claim 1, characterized in that, When performing FOC control on the motor speed, the given current parameter is calibrated using the elastic calibration value, specifically including: Obtain the command speed signal of the motor; Based on the command speed signal and the feedback speed signal, the initial q-axis command current is obtained through PI control; The calibrated q-axis command current is obtained by subtracting the elastic calibration value from the initial q-axis command current.

5. The motor speed control method for the lifting and transferring machine according to claim 4, characterized in that, Also includes: Given the d-axis command current; Collect the actual three-phase current of the motor; The actual three-phase current is transformed into d-axis feedback current and q-axis feedback current; The motor is subjected to SVPWM control based on the calibrated q-axis command current, the q-axis feedback current, the d-axis command current, and the d-axis feedback current.

6. A motor speed control device for a lifting and transferring machine, characterized in that, The lifting and transferring machine includes a rotating shaft, a cam mounted on the rotating shaft, and a motor driving the rotating shaft. An elastic buffer layer is provided between the cam and the object being lifted. The device includes: The detection module is used to detect the displacement signal of the object being lifted. An acquisition module is used to acquire the feedback speed signal of the motor based on the displacement signal; The calculation module is used to perform bandpass filtering on the feedback speed signal and calculate the elastic calibration value based on the filtered signal. The calibration module is used to calibrate the given current parameter with the elastic calibration value when the speed of the motor is under FOC control, so as to calibrate the speed of the motor and the displacement of the object being lifted.

7. The motor speed control device for the lifting and transferring machine according to claim 6, characterized in that, The feedback speed signal is: Wherein, n represents the feedback speed signal, I is the ratio of the motor speed to the cam speed, f(S) represents the expression of the theoretical lifting displacement S of the cam with respect to the rotation angle of the cam, and d / dt represents the derivative with respect to time t.

8. The motor speed control device for the lifting and transferring machine according to claim 6, characterized in that, The calculation module is specifically used for: The filtered signal is obtained after passing through the bandpass filter: Where y represents the filtered signal, which is a function of time t, and ω HP ω is the lower passband limit of the bandpass filter. LP τ is the upper passband limit of the bandpass filter, τ is the integration time variable, and n(τ) represents the value of the feedback speed signal at τ. The elastic calibration value is calculated based on the filtered signal: i cal =α·y Among them, i cal The elastic calibration value is given, and α is the current-to-speed ratio coefficient.

9. The motor speed control device for the lifting and transferring machine according to claim 6, characterized in that, The calibration module is specifically used for: Obtain the command speed signal of the motor; Based on the command speed signal and the feedback speed signal, the initial q-axis command current is obtained through PI control; The calibrated q-axis command current is obtained by subtracting the elastic calibration value from the initial q-axis command current.

10. A lifting and transferring machine, characterized in that, Includes a motor speed control device for a lifting and transferring machine according to any one of claims 6-9.

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