Numerical control shaft positioning correction and compensation method and device, storage medium and electronic equipment

Abstract

The invention relates to the field of mechanical part machining, in particular to a numerical control shaft positioning correction and compensation method and device, a storage medium and electronic equipment. The method comprises the following steps: acquiring initial positioning data of a numerical control shaft; determining actual mechanical characteristic parameters of the numerical control shaft according to the initial positioning data; correcting the systematic positioning error value of the numerical control shaft according to the theoretical mechanical characteristic parameter and the actual mechanical characteristic parameter of the numerical control shaft to obtain corrected positioning data of the numerical control shaft; and according to the corrected positioning data, performing reverse difference compensation on the randomness error of the numerical control shaft to obtain target positioning data of the numerical control shaft. According to the method, the systematic positioning error value of the numerical control shaft is accurately corrected, so that the system error of the equipment is eliminated. Meanwhile, reverse difference compensation is carried out on random errors of the equipment, the positioning precision of the numerical control shaft is remarkably improved, the performance of the equipment is optimized, and a new way is opened up for improving the positioning precision of the numerical control shaft.

Description

Technical Field

[0001] The present invention relates to the field of mechanical parts processing, and in particular to a method, device, storage medium and electronic equipment for positioning correction and compensation of a numerical control axis. Background Art

[0002] With the rapid development of modern manufacturing industry, especially in the occasions with high precision requirements such as large component assembly and mechanical parts processing, the precision requirements for assembly (processing) equipment are increasing day by day. The production of high-precision products not only depends on advanced manufacturing processes and materials, but also on the support of high-precision equipment. The precision of equipment parts, assembly precision and control system precision are directly related to the quality and performance of the final product.

[0003] In order to meet this market demand, improving equipment accuracy has become an important challenge facing the manufacturing industry. On the one hand, the manufacturing accuracy of equipment parts needs to reach a higher standard to ensure the accuracy of the equipment itself; on the other hand, precision control during the assembly process is also crucial, as any slight assembly error may have a significant impact on the performance of the final product.

[0004] In addition, the accuracy of the control system and the accuracy compensation measures are also the key to improving the accuracy of the equipment. Traditional control systems may not be able to meet the control accuracy requirements of high-precision equipment, so more advanced control algorithms and accuracy compensation technologies are needed to reduce or eliminate the impact of various errors on equipment accuracy.

[0005] In summary, in order to meet the needs of high-precision occasions such as large component assembly and mechanical parts processing, it is necessary to ensure that the equipment parts and assembly have high precision, and at the same time require the control system to have high control accuracy and precision compensation measures. This has put forward new requirements and challenges for the technological progress and industrial upgrading of the modern manufacturing industry. Summary of the invention

[0006] The main purpose of the present invention is to provide a method, device, storage medium and electronic device for CNC axis positioning correction and compensation, aiming to solve the technical problem of low CNC axis positioning accuracy in the prior art.

[0007] To achieve the above objectives, the present disclosure proposes a CNC axis positioning correction and compensation method, comprising:

[0008] Get the initial positioning data of the CNC axis;

[0009] Determining actual mechanical characteristic parameters of the CNC axis according to the initial positioning data;

[0010] According to the theoretical mechanical characteristic parameters of the numerical control axis and the actual mechanical characteristic parameters, the systematic positioning error value of the numerical control axis is corrected to obtain the corrected positioning data of the numerical control axis;

[0011] According to the corrected positioning data, reverse difference compensation is performed on the random error of the numerical control axis to obtain the target positioning data of the numerical control axis.

[0012] Optionally, the correcting the systematic positioning error value of the CNC axis according to the theoretical mechanical characteristic parameters and the actual mechanical characteristic parameters of the CNC axis to obtain the corrected positioning data of the CNC axis includes:

[0013] Calculating a system theoretical displacement unit and a system actual displacement unit of the numerical control axis according to the theoretical mechanical characteristic parameters and the actual mechanical characteristic parameters;

[0014] Calculating the theoretical pulse equivalent and the actual pulse equivalent of the numerical control axis according to the theoretical displacement unit of the system and the actual displacement unit of the system;

[0015] Calculating the theoretical displacement and the actual displacement of the numerical control axis according to the theoretical pulse equivalent and the actual pulse equivalent;

[0016] Calculating a systematic positioning error value of the numerical control axis according to the actual displacement and the theoretical displacement;

[0017] The systematic positioning error value is corrected to obtain the corrected positioning data of the numerical control axis.

[0018] Optionally, the correcting the systematic positioning error value to obtain the corrected positioning data of the CNC axis includes:

[0019] Determining a proportional function of the pulse command displacement according to the systematic positioning error value;

[0020] Determine a first functional relationship of the axis systematic positioning error value of the numerical control axis according to the straight line fitting result and the direct proportional function;

[0021] Determine a second functional relationship corresponding to the system transmission parameter formula of the CNC axis according to the first functional relationship;

[0022] According to the second functional relationship, determining a systematic error correction functional relationship of the numerical control axis;

[0023] Based on the systematic error correction function relationship, the systematic positioning error value is corrected to obtain the corrected positioning data.

[0024] Optionally, the correcting the systematic positioning error value based on the systematic error correction function relationship to obtain the corrected positioning data includes:

[0025] Correcting one or more of the actual speed ratio between the motor encoder and the motor, the actual speed ratio between the motor and the lead screw reducer, and the actual pitch in the systematic error correction function relationship to correct the systematic positioning error value;

[0026] If the digital control system corresponding to the CNC axis is a semi-closed loop system, the systematic error correction function relationship is expressed as:

[0027]

[0028] If the digital control system corresponding to the CNC axis is a fully closed-loop system, the systematic error correction function relationship is expressed as:

[0029] t=(1+k)*t0

[0030] Among them, λ0 is the theoretical speed ratio between the motor encoder and the motor, λ is the actual speed ratio between the motor encoder and the motor, t0 is the theoretical pitch, t is the actual pitch, I0 is the theoretical speed ratio between the motor and the screw reducer, I is the actual speed ratio between the motor and the screw reducer, and k is the proportional coefficient.

[0031] Optionally, performing reverse difference compensation on the random error of the numerical control axis according to the corrected positioning data to obtain the target positioning data of the numerical control axis includes:

[0032] Determining a random error data set of the numerical control axis according to the corrected positioning data;

[0033] Determining a random error compensation point of the numerical control axis according to the random error data set;

[0034] The position of the random error compensation point is reversely compensated by reverse difference to obtain the target positioning data.

[0035] Optionally, determining the actual mechanical characteristic parameters of the CNC axis according to the initial positioning data includes:

[0036] Determining a systematic error data set of the numerical control axis according to the initial positioning data;

[0037] Using the least square method to perform straight line fitting on the systematic error data set to obtain the straight line fitting result;

[0038] The actual mechanical characteristic parameters are calculated according to the straight line fitting result.

[0039] Optionally, after performing reverse difference compensation on the random error of the numerical control axis according to the corrected positioning data, the method further includes:

[0040] The CNC axis after reverse difference compensation is measured to obtain the measurement result;

[0041] Determining positioning error data of each measuring point of the numerical control axis according to the measurement result and the target positioning data;

[0042] Evaluating the positioning error data of each measuring point of the CNC axis to obtain an evaluation result;

[0043] If the evaluation result meets the preset error condition, the target positioning data is determined as the final positioning data of the numerical control axis.

[0044] In addition, to achieve the above-mentioned purpose, the present disclosure also provides a numerical control axis positioning correction and compensation device, the numerical control axis positioning correction and compensation device comprising:

[0045] An acquisition module is used to acquire the initial positioning data of the CNC axis;

[0046] A determination module, used to determine actual mechanical characteristic parameters of the CNC axis according to the initial positioning data;

[0047] A correction module, used for correcting the systematic positioning error value of the numerical control axis according to the theoretical mechanical characteristic parameters of the numerical control axis and the actual mechanical characteristic parameters, so as to obtain the corrected positioning data of the numerical control axis;

[0048] The compensation module is used to perform reverse difference compensation on the random error of the numerical control axis according to the corrected positioning data to obtain the target positioning data of the numerical control axis.

[0049] In addition, to achieve the above objectives, the present disclosure also provides a computer-readable storage medium, on which a computer program is stored, and a processor executes the computer program to implement the above method.

[0050] In addition, to achieve the above-mentioned purpose, the present disclosure also provides an electronic device, which includes a memory and a processor, wherein the memory stores a computer program, and the processor executes the computer program to implement the above-mentioned method.

[0051] In addition, to achieve the above objectives, the present disclosure also provides a computer program product, which implements the above method when executed by a processor.

[0052] The CNC axis positioning correction and compensation method, device, storage medium and electronic device proposed in the embodiments of the present disclosure obtain the initial positioning data of the CNC axis and determine its actual mechanical characteristic parameters accordingly, so that the system can accurately identify the inherent deviations of the CNC axis in manufacturing and actual operation. Further, according to the theoretical mechanical characteristic parameters and actual mechanical characteristic parameters of the CNC axis, the systematic positioning error value is corrected to ensure that the positioning reference of the CNC axis is more accurate, greatly improving the stability and reliability of positioning. On the basis of the correction of the systematic error, the random error of the CNC axis is compensated for by reverse difference. The random errors caused by factors such as mechanical characteristic non-uniformity and damping characteristic fluctuation can be accurately calculated, and the influence of random errors on the positioning accuracy of the CNC axis is effectively reduced, further improving the accuracy of CNC axis positioning. It is of great significance to the fields of mechanical manufacturing, aerospace, precision instruments, etc. that require high-precision positioning control. BRIEF DESCRIPTION OF THE DRAWINGS

[0053] In order to more clearly illustrate the embodiments of the present disclosure or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present disclosure. For ordinary technicians in this field, other drawings can be obtained based on the structures shown in these drawings without paying any creative work.

[0054] Figure 1 A schematic diagram of the device structure of the hardware operating environment involved in the embodiment of the present disclosure;

[0055] Figure 2 A schematic diagram of a flow chart of a method for positioning, correcting and compensating a numerical control axis according to an embodiment of the present disclosure;

[0056] Figure 3 A schematic diagram of the structural connection of a digital control system involved in an embodiment of the present disclosure.

[0057] Figure 4 It is a schematic diagram of an axis displacement error curve during an initial setting involved in an embodiment of the present disclosure.

[0058] Figure 5 It is a schematic diagram of an axis displacement error curve after a systematic error correction involved in an embodiment of the present disclosure.

[0059] Figure 6 It is a schematic diagram of an axis displacement error curve after random error compensation involved in an embodiment of the present disclosure.

[0060] Figure 7 This is a structural block diagram of a CNC axis positioning correction and compensation device involved in the embodiment of the present disclosure.

[0061] The realization of the objectives, functional features and advantages of the present disclosure will be further described in conjunction with embodiments and with reference to the accompanying drawings. DETAILED DESCRIPTION

[0062] The following will be combined with the drawings in the embodiments of the present disclosure to clearly and completely describe the technical solutions in the embodiments of the present disclosure. Obviously, the described embodiments are only part of the embodiments of the present disclosure, rather than all the embodiments. Based on the embodiments in the present disclosure, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present disclosure.

[0063] Reference Figure 1 , Figure 1 The figure is a schematic diagram of the device structure of the hardware operating environment involved in the embodiment of the present disclosure.

[0064] Typically, the device includes: at least one processor 301, a memory 302, and a CNC axis positioning correction and compensation program stored in the memory 302 and executable on the processor 301, wherein the CNC axis positioning correction and compensation program is configured to implement the steps of the previous CNC axis positioning correction and compensation method.

[0065] The processor 301 may include one or more processing cores, such as a 4-core processor, an 8-core processor, etc. The processor 301 may be implemented in at least one hardware form of DSP (Digital Signal Processing), FPGA (Field-Programmable Gate Array), and PLA (Programmable Logic Array). The processor 301 may also include a main processor and a coprocessor. The main processor is a processor for processing data in the awake state, also known as a CPU (Central Processing Unit); the coprocessor is a low-power processor for processing data in the standby state. In some embodiments, the processor 301 may be integrated with a GPU (Graphics Processing Unit), which is responsible for rendering and drawing the content to be displayed on the display screen. The processor 301 may also include an AI (Artificial Intelligence) processor, which is used to process the operation of the CNC axis positioning correction and compensation method, so that the CNC axis positioning correction and compensation method model can be trained and learned autonomously to improve efficiency and accuracy.

[0066] The memory 302 may include one or more storage media, which may be non-transitory. The memory 302 may also include a high-speed random access memory, and a non-volatile memory, such as one or more disk storage devices, flash memory storage devices. In some embodiments, the non-transitory storage medium in the memory 302 is used to store at least one instruction, which is used to be executed by the processor 301 to implement the CNC axis positioning correction and compensation method provided in the method embodiment of the present disclosure.

[0067] In some embodiments, the terminal may further optionally include: a communication interface 303 and at least one peripheral device. The processor 301, the memory 302 and the communication interface 303 may be connected via a bus or a signal line. Each peripheral device may be connected to the communication interface 303 via a bus, a signal line or a circuit board. Specifically, the peripheral device includes: at least one of a radio frequency circuit 304, a display screen 305 and a power supply 306.

[0068] The communication interface 303 may be used to connect at least one peripheral device related to I / O (Input / Output) to the processor 301 and the memory 302. In some embodiments, the processor 301, the memory 302, and the communication interface 303 are integrated on the same chip or circuit board; in some other embodiments, any one or two of the processor 301, the memory 302, and the communication interface 303 may be implemented on a separate chip or circuit board, which is not limited in this embodiment.

[0069] The radio frequency circuit 304 is used to receive and transmit RF (Radio Frequency) signals, also known as electromagnetic signals. The radio frequency circuit 304 communicates with the communication network and other communication devices through electromagnetic signals. The radio frequency circuit 304 converts electrical signals into electromagnetic signals for transmission, or converts received electromagnetic signals into electrical signals. Optionally, the radio frequency circuit 304 includes: an antenna system, an RF transceiver, one or more amplifiers, a tuner, an oscillator, a digital signal processor, a codec chipset, a user identity module card, and the like. The radio frequency circuit 304 can communicate with other terminals through at least one wireless communication protocol. The wireless communication protocol includes, but is not limited to: a metropolitan area network, various generations of mobile communication networks (2G, 3G, 4G and 5G), a wireless local area network and / or a WiFi (Wireless Fidelity) network. In some embodiments, the radio frequency circuit 304 may also include circuits related to NFC (Near Field Communication), which is not limited in the present disclosure.

[0070] The display screen 305 is used to display the UI (User Interface). The UI may include graphics, text, icons, videos, and any combination thereof. When the display screen 305 is a touch display screen, the display screen 305 also has the ability to collect touch signals on the surface or above the surface of the display screen 305. The touch signal can be input to the processor 301 as a control signal for processing. At this time, the display screen 305 can also be used to provide virtual buttons and / or virtual keyboards, also known as soft buttons and / or soft keyboards. In some embodiments, the display screen 305 can be one, the front panel of the electronic device; in other embodiments, the display screen 305 can be at least two, respectively arranged on different surfaces of the electronic device or in a folding design; in some embodiments, the display screen 305 can be a flexible display screen, arranged on a curved surface or a folding surface of the electronic device. Even, the display screen 305 can also be set to a non-rectangular irregular shape, that is, a special-shaped screen. The display screen 305 can be made of materials such as LCD (Liquid Crystal Display), OLED (Organic Light-Emitting Diode, organic light-emitting diode).

[0071] The power supply 306 is used to power various components in the electronic device. The power supply 306 can be AC ​​power, DC power, a disposable battery, or a rechargeable battery. When the power supply 306 includes a rechargeable battery, the rechargeable battery can support wired charging or wireless charging. The rechargeable battery can also be used to support fast charging technology. Those skilled in the art will understand that Figure 1 The structure shown in the figure does not constitute a limitation of the device, and may include more or less components than shown in the figure, or combine certain components, or arrange the components differently.

[0072] In addition, the embodiment of the present disclosure also proposes a storage medium, on which a CNC axis positioning correction and compensation program is stored, and when the CNC axis positioning correction and compensation program is executed by the processor, the steps of the CNC axis positioning correction and compensation method as described above are implemented. Therefore, it will not be repeated here. In addition, the description of the beneficial effects of adopting the same method will not be repeated. For technical details not disclosed in the storage medium embodiment involved in the present disclosure, please refer to the description of the method embodiment of the present disclosure. As an example, the program instructions can be deployed to be executed on one device, or on multiple devices located at one location, or on multiple devices distributed at multiple locations and interconnected by a communication network.

[0073] Those skilled in the art can understand that all or part of the processes in the above-mentioned embodiments can be implemented by instructing related hardware through a computer program, and the above-mentioned program can be stored in a storage medium, and when the program is executed, it can include the processes of the embodiments of the above-mentioned methods. Among them, the above-mentioned storage medium can be a disk, an optical disk, a read-only memory (ROM) or a random access memory (RAM), etc.

[0074] In related technologies, the positioning error of CNC axes can be divided into two categories: systematic error and random error. Systematic error mainly comes from the key parameter settings of the axis, such as pitch, screw pitch, transmission ratio, etc. The configuration of these parameters directly affects the generation of errors. Random error is closely related to the non-uniformity of the mechanical characteristics of the axis drive throughout the entire stroke, which is specifically reflected in the fluctuation of the damping characteristics and the slight fluctuations of parameters such as pitch, screw pitch, grating pitch, transmission ratio, etc.

[0075] At present, the compensation scheme for CNC axis positioning errors mainly focuses on the compensation of random errors, but ignores the correction of system errors. Since the actual value of mechanical characteristic parameters is difficult to be completely consistent with the theoretical value during the mechanical manufacturing process, fixed system errors are inevitable. These errors are measurable, reproducible and unidirectional. Their existence will directly affect the size of the system instruction pulse equivalent, thereby further affecting the accuracy of the axis movement position.

[0076] In view of this, the present disclosure provides a CNC axis positioning correction and compensation method to solve the above technical problems.

[0077] Reference Figure 2 , Figure 2 The present invention is a flowchart of a method for positioning, correcting and compensating a numerical control axis according to an embodiment of the present invention, which includes the following steps:

[0078] Step S11: Obtain the initial positioning data of the CNC axis.

[0079] Step S12: Determine the actual mechanical characteristic parameters of the CNC axis according to the initial positioning data.

[0080] Step S13: Correcting the systematic positioning error value of the CNC axis according to the theoretical mechanical characteristic parameters and the actual mechanical characteristic parameters of the CNC axis to obtain the corrected positioning data of the CNC axis.

[0081] Step S14: According to the corrected positioning data, reverse difference compensation is performed on the random error of the CNC axis to obtain the target positioning data of the CNC axis.

[0082] First, it should be understood that the CNC axis positioning correction and compensation method disclosed in the present invention can be applied to digital control systems. Figure 3 FIG. 1 is a schematic diagram of a structural connection of a digital control system involved in the embodiment of the present disclosure. Figure 3 As shown, the digital control system may include an encoder, a servo motor, a reducer, a lead screw, a grating ruler, a servo unit and a control system.

[0083] For example, before controlling the movement of the axis, parameters matching the mechanical characteristics can be set in the digital control system to achieve precise control of the axis movement position. After the parameter setting is completed, the digital control system performs calculations, converts the mechanical characteristic parameters into command pulses, and sends them to the servo unit, which controls the axis movement to achieve axis position control.

[0084] First, the initial mechanical characteristic parameters of the axis are set according to the theoretical values ​​in the setting interface of the digital control system, including the lead screw pitch, the transmission ratio of the motor to the lead screw, and the transmission ratio of the motor to the encoder.

[0085] Through the above technical solution, by obtaining the initial positioning data of the CNC axis and determining its actual mechanical characteristic parameters accordingly, the system can accurately identify the inherent deviations of the CNC axis in manufacturing and actual operation. Further, according to the theoretical mechanical characteristic parameters and actual mechanical characteristic parameters of the CNC axis, the systematic positioning error value is corrected to ensure that the positioning reference of the CNC axis is more accurate, greatly improving the stability and reliability of positioning. On the basis of the correction of the systematic error, the random error of the CNC axis is compensated for by reverse difference. The random errors caused by factors such as mechanical characteristic non-uniformity and damping characteristic fluctuation can be accurately calculated, and the influence of random errors on the positioning accuracy of the CNC axis is effectively reduced, further improving the accuracy of CNC axis positioning. It is of great significance to the fields of mechanical manufacturing, aerospace, precision instruments, etc. that require high-precision positioning control.

[0086] Furthermore, the technical solution is easy to operate, and does not require complex transformation or replacement of the CNC axis. Error correction and compensation can be achieved through software algorithms and data processing. At the same time, the solution is suitable for CNC axes of various types and specifications, and has strong applicability and universality. In addition, compared with replacing high-precision CNC axes or adopting other complex solutions, the technical solution is low-cost and can significantly improve the positioning accuracy of CNC axes. This saves a lot of costs for enterprises, improves production efficiency and product quality, and brings high cost-effectiveness.

[0087] In possible ways, the actual mechanical characteristic parameters of the CNC axis are determined based on the initial positioning data, including:

[0088] According to the initial positioning data, the systematic error data set of the CNC axis is determined;

[0089] The least square method is used to perform straight line fitting on the systematic error data set to obtain the straight line fitting result;

[0090] According to the straight line fitting results, the actual mechanical characteristic parameters are calculated.

[0091] For example, based on the initial positioning data, the systematic error data set of the CNC axis can be determined by first controlling the CNC axis to move according to a preset movement method, and the moving distance can be the positive and negative stroke of the locator axis. Then, the position of the CNC axis is measured by a laser interferometer to obtain secondary measurement data of each measuring point. Calculation is performed based on the initial positioning data and the secondary measurement data to obtain the positioning error data of each measuring point of the CNC axis, and then the systematic error data set of the CNC axis is obtained.

[0092] For the N+1 sets of positioning error data (a m , E m ), m∈N, N is a natural number, a m It is the equal-proportional dividing point of the CNC moving distance, that is, the measuring point, which can be divided into N segments. m is the error data measured at each average point. The displacement error curve of each positioning error data in the systematic error data set satisfies the following set relationship:

[0093] (a, E) = {(a0, E0), (a1, E1), (a2, E2), (a m , E m ), …(a N , E N )} (1)

[0094] Among them, a0, a1, a2, a m , …, a N are measuring points, E0, E1, E2, E m …E N are the error data corresponding to each measurement point.

[0095] Figure 4 Schematic diagram of an axis displacement error curve during initial setting of an embodiment of the present disclosure. The systematic error data set of the CNC axis can be as follows: Figure 4 The displacement error curve is shown in 9.

[0096] For example, the least squares method is used to perform a straight line fit on the systematic error data set, and the following can be obtained: Figure 4 The fitting straight line shown in 8. The fitting straight line satisfies the following system error data fitting relationship (2):

[0097] E=ka+b (2)

[0098] Among them, E is the systematic positioning error value of the axis, k is the proportional coefficient, and b is the fitting backlash.

[0099] The least squares method is used to fit the straight line 8, and the sampling point (a m , E m ) to the straight line distance d m The sum of squares is the smallest. According to the distance formula from a plane point to a straight line, the straight line distance d can be obtained. m The square of d m 2 for:

[0100]

[0101] The distance formula from a plane point to a straight line is:

[0102]

[0103] Among them, b and k are variables, which can make the point (a m , E m ) to the straight line distance d m The sum of squares is the smallest, specifically:

[0104]

[0105] Therefore, the variables b and k can be solved by the following calculation formula:

[0106]

[0107] In a possible manner, according to the theoretical mechanical characteristic parameters and the actual mechanical characteristic parameters of the CNC axis, the systematic positioning error value of the CNC axis is corrected to obtain the corrected positioning data of the CNC axis, including:

[0108] According to the theoretical mechanical characteristic parameters and the actual mechanical characteristic parameters, the system theoretical displacement unit and the system actual displacement unit of the CNC axis are calculated;

[0109] Calculate the theoretical pulse equivalent and actual pulse equivalent of the CNC axis according to the system theoretical displacement unit and the system actual displacement unit;

[0110] According to the theoretical pulse equivalent and the actual pulse equivalent, the theoretical displacement and the actual displacement of the CNC axis are calculated;

[0111] Calculate the systematic positioning error value of the CNC axis based on the actual displacement and theoretical displacement;

[0112] Correct the systematic positioning error value to obtain the corrected positioning data of the CNC axis.

[0113] For example, the theoretical speed ratio between the motor and the screw reducer is i0, and the actual speed ratio is i. The theoretical speed ratio between the motor encoder and the motor is λ0, and the actual speed ratio is λ. The theoretical pitch (i.e., the grating pitch) is t0, where, if the digital control system corresponding to the CNC axis is a semi-closed loop system, t0 uses the screw pitch, and if the digital control system corresponding to the CNC axis is a fully closed loop system, t0 uses the grating scale pitch, and the actual pitch (i.e., the grating pitch) is t.

[0114] The displacement unit refers to the displacement of the CNC axis per rotation of the encoder (μm / rev). If the digital control system corresponding to the CNC axis is a semi-closed loop system, the theoretical displacement unit of the system is δ L0 and the actual displacement unit of the system δ L The following relationship (3) is satisfied:

[0115]

[0116] If the digital control system corresponding to the CNC axis is a fully closed-loop system, the system theoretical displacement unit δ L0 and the actual displacement unit of the system δ L The following relationship (3) is satisfied:

[0117]

[0118] For example, pulse equivalent is how many μm a command pulse sent by a digital control system to a servo unit represents, and is the smallest command unit for controlling the movement of a servo unit. The total number of pulses returned by the motor encoder or grating ruler is A, the theoretical pulse equivalent of the servo system is P0, and the actual pulse equivalent is P. The functional relationship between the theoretical pulse equivalent of P0 and the actual pulse equivalent of P and the parameters of each device is:

[0119] If the digital control system corresponding to the CNC axis is a semi-closed loop system, the functional relationship between the theoretical pulse equivalent P0 and the actual pulse equivalent P and the parameters of each device (4) is:

[0120]

[0121] If the digital control system corresponding to the CNC axis is a fully closed-loop system, the functional relationship between the theoretical pulse equivalent P0 and the actual pulse equivalent P and the parameters of each device (4) is:

[0122]

[0123] For example, the command pulse number is the theoretical displacement value δ received by the digital control system from the CNC machining program. a0 After that, it is decoded by the CNC device and converted into the total number of pulses.

[0124] If the digital control system corresponding to the CNC axis is a semi-closed loop system, the number of command pulses Np Satisfies the following functional relationship (5):

[0125]

[0126] If the digital control system corresponding to the CNC axis is a fully closed-loop system, the number of command pulses N p The following functional relationship (5) is satisfied:

[0127]

[0128] Therefore, if the digital control system corresponding to the CNC axis is a semi-closed loop system, the actual displacement δ a Satisfies the following functional relationship (6):

[0129]

[0130] If the digital control system corresponding to the CNC axis is a fully closed-loop system, the actual displacement δ a Satisfies the following functional relationship (6):

[0131]

[0132] In a possible manner, the systematic positioning error value is corrected to obtain the corrected positioning data of the CNC axis, including:

[0133] According to the systematic positioning error value, a proportional function of the pulse command displacement is determined;

[0134] According to the straight line fitting result and the direct proportional function, a first functional relationship of the axis systematic positioning error value of the numerical control axis is determined;

[0135] According to the first functional relationship, a second functional relationship corresponding to the system transmission parameter formula of the numerical control axis is determined;

[0136] According to the second functional relationship, a systematic error correction functional relationship of the numerical control axis is determined;

[0137] Based on the systematic error correction function relationship, the systematic positioning error value is corrected to obtain the corrected positioning data.

[0138] For example, the axis systematic positioning error value is the theoretical displacement of the digital control system δ a0 The actual displacement δ a The difference between them, k2 is the proportional coefficient of the direct proportional function.

[0139] If the digital control system corresponding to the CNC axis is a semi-closed loop system, the axis systematic positioning error value E satisfies the following functional relationship (7):

[0140]

[0141] If the digital control system corresponding to the CNC axis is a fully closed-loop system, the axis systematic positioning error value E satisfies the following functional relationship (7):

[0142]

[0143] According to the functional relationship (7) of the axis systematic positioning error value E, it can be obtained that the axis systematic positioning error value E satisfies the following axis systematic positioning error value function (7) and is a positive proportional function of the pulse displacement:

[0144] E=k2*δ a0 (7)

[0145] If the digital control system corresponding to the CNC axis is a semi-closed loop system, the proportional coefficient k2 satisfies the following functional relationship (8):

[0146]

[0147] If the digital control system corresponding to the CNC axis is a fully closed-loop system, the proportional coefficient k2 satisfies the following functional relationship (8):

[0148]

[0149] For example, since the above-mentioned system error data fitting relationship (2) and the axis systematic positioning error value function (7) are both directly proportional functions of position and error, they have strong correlation terms and their slopes can be approximately equal, that is, k≈k2. Therefore, if the digital control system corresponding to the CNC axis is a semi-closed loop system, (8) can be equivalent to the functional relationship shown in (9), and the first functional relationship corresponding to the systematic positioning error value, that is, the first functional relationship about the proportional coefficient k is:

[0150]

[0151] If the digital control system corresponding to the CNC axis is a fully closed-loop system, the first functional relationship of the proportional coefficient k is:

[0152]

[0153] For example, a second functional relationship corresponding to the system transmission parameter formula can be obtained based on the above first functional relationship.

[0154] If the digital control system corresponding to the CNC axis is a semi-closed loop system, the second functional relationship (10) is:

[0155] I*λ*t=(1+k)*I0*λ0*t0 (10)

[0156] If the digital control system corresponding to the CNC axis is a fully closed-loop system, the second functional relationship (10) is:

[0157] t=(1+k)*t0 (10)

[0158] Then, according to the second functional relationship, the systematic error correction functional relationship of the numerical control axis is determined, and finally, based on the systematic error correction functional relationship, the systematic error of the numerical control axis is corrected.

[0159] In a possible manner, based on a systematic error correction function relationship, the systematic positioning error value is corrected to obtain corrected positioning data, including:

[0160] Correcting one or more of the actual speed ratio between the motor encoder and the motor, the actual speed ratio between the motor and the screw reducer, and the actual pitch in the systematic error correction function relationship to correct the systematic positioning error value;

[0161] If the digital control system corresponding to the CNC axis is a semi-closed loop system, the systematic error correction function relationship is expressed as:

[0162]

[0163] If the digital control system corresponding to the CNC axis is a fully closed-loop system, the systematic error correction function relationship is expressed as:

[0164] t=(1+k)*t0

[0165] Among them, λ0 is the theoretical speed ratio between the motor encoder and the motor, λ is the actual speed ratio between the motor encoder and the motor, t0 is the theoretical pitch, t is the actual pitch, I0 is the theoretical speed ratio between the motor and the screw reducer, I is the actual speed ratio between the motor and the screw reducer, and k is the proportional coefficient.

[0166] For example, Figure 5 The following is a schematic diagram of an axis displacement error curve after a systematic error correction according to the embodiment of the present disclosure. According to the above-mentioned systematic error correction function relationship, one or more values ​​of I, λ, and t calculated are input into the control system, and the correction of the systematic positioning error value can be completed. After the correction, the following can be obtained: Figure 5 The axis displacement error curve is shown.

[0167] In a possible manner, the random error of the CNC axis is reversely compensated according to the corrected positioning data to obtain the target positioning data of the CNC axis, including:

[0168] Determine the random error data set of the CNC axis based on the corrected positioning data;

[0169] According to the random error data set, the random error compensation point of the CNC axis is determined;

[0170] The position of the random error compensation point is compensated by reverse difference to obtain the target positioning data.

[0171] For example, after correcting the systematic positioning error value, the CNC axis can continue to be controlled to move, and the moving distance is the positive and negative travel of the positioner axis. The position of the axis is measured using a laser interferometer, and the following information can be obtained: Figure 5 The random error data of the axis displacement of each measuring point shown is the random error data set of the CNC axis, and satisfies the set relationship shown in formula (1).

[0172] It should be understood that random errors are mainly related to the non-uniformity of the mechanical characteristics of the shaft drive over the entire stroke (fluctuations in the damping characteristics), as well as fluctuations in pitch, thread pitch, grating pitch, and transmission ratio. Random errors can only be achieved by changing the target position of the movement.

[0173] Therefore, by Figure 5 The random error data of the axis displacement at each measuring point shown in the figure and the error data set relationship of formula (1) are used to obtain the random error value E of each average point and the position value a of each average point of the axis. m , the theoretical movement of the axis along the axis in the device coordinate system is L m0 , the amount of movement should be L m , a m-1 <=L m0 =a m Calculate the error data obtained and use the reverse difference method to compensate the position of the target point. The amount of movement should be L m Satisfies the functional relationship shown in formula (11):

[0174]

[0175] Figure 6 This is a schematic diagram of an axis displacement error curve after random error compensation involved in the embodiment of the present disclosure. After compensation, it can be obtained Figure 6 The axis displacement error curve is shown.

[0176] In a possible manner, after performing reverse difference compensation on the random error of the CNC axis according to the corrected positioning data, the method further includes:

[0177] The CNC axis after reverse difference compensation is measured to obtain the measurement result;

[0178] According to the measurement results and target positioning data, determine the positioning error data of each measuring point of the CNC axis;

[0179] Evaluate the positioning error data of each measuring point of the CNC axis to obtain an evaluation result;

[0180] If the evaluation result meets the preset error condition, the target positioning data is determined as the final positioning data of the CNC axis.

[0181] For example, a laser interferometer can be used to measure the position of the axis, and the positioning error data of each measuring point can be obtained, and the statistical test method of VDI3441 machine tool operation accuracy and positioning accuracy can be used for evaluation. If the evaluation result does not meet the preset error condition, the systematic error correction and / or random error compensation will continue. The preset error condition can be set according to the actual accuracy requirement, and the embodiment of the present disclosure does not specifically limit this.

[0182] Reference Figure 7 , Figure 7 This is a structural block diagram of a CNC axis positioning correction and compensation device involved in the embodiment of the present disclosure. Based on the same inventive concept as the above embodiment, the device includes:

[0183] An acquisition module 10 is used to acquire the initial positioning data of the CNC axis;

[0184] A determination module 20, configured to determine actual mechanical characteristic parameters of the CNC axis according to the initial positioning data;

[0185] A correction module 30, used for correcting the systematic positioning error value of the numerical control axis according to the theoretical mechanical characteristic parameters of the numerical control axis and the actual mechanical characteristic parameters, so as to obtain the corrected positioning data of the numerical control axis;

[0186] The compensation module 40 is used to perform reverse difference compensation on the random error of the numerical control axis according to the corrected positioning data to obtain the target positioning data of the numerical control axis.

[0187] Optionally, the correction module 30 is used to:

[0188] Calculating a system theoretical displacement unit and a system actual displacement unit of the numerical control axis according to the theoretical mechanical characteristic parameters and the actual mechanical characteristic parameters;

[0189] Calculating the theoretical pulse equivalent and the actual pulse equivalent of the numerical control axis according to the theoretical displacement unit of the system and the actual displacement unit of the system;

[0190] Calculating the theoretical displacement and the actual displacement of the numerical control axis according to the theoretical pulse equivalent and the actual pulse equivalent;

[0191] Calculating a systematic positioning error value of the numerical control axis according to the actual displacement and the theoretical displacement;

[0192] The systematic positioning error value is corrected to obtain the corrected positioning data of the numerical control axis.

[0193] Optionally, the correction module 30 is used to:

[0194] Determining a proportional function of the pulse command displacement according to the systematic positioning error value;

[0195] Determine a first functional relationship of the axis systematic positioning error value of the numerical control axis according to the straight line fitting result and the direct proportional function;

[0196] Determine a second functional relationship corresponding to the system transmission parameter formula of the CNC axis according to the first functional relationship;

[0197] According to the second functional relationship, determining a systematic error correction functional relationship of the numerical control axis;

[0198] Based on the systematic error correction function relationship, the systematic positioning error value is corrected to obtain the corrected positioning data.

[0199] Optionally, the correction module 30 is used to:

[0200] Correcting one or more of the actual speed ratio between the motor encoder and the motor, the actual speed ratio between the motor and the lead screw reducer, and the actual pitch in the systematic error correction function relationship to correct the systematic positioning error value;

[0201] If the digital control system corresponding to the CNC axis is a semi-closed loop system, the systematic error correction function relationship is expressed as:

[0202]

[0203] If the digital control system corresponding to the CNC axis is a fully closed-loop system, the systematic error correction function relationship is expressed as:

[0204] t=(1+k)*t0

[0205] Among them, λ0 is the theoretical speed ratio between the motor encoder and the motor, λ is the actual speed ratio between the motor encoder and the motor, t0 is the theoretical pitch, t is the actual pitch, I0 is the theoretical speed ratio between the motor and the screw reducer, I is the actual speed ratio between the motor and the screw reducer, and k is the proportional coefficient.

[0206] Optionally, the compensation module 40 is used to:

[0207] Determining a random error data set of the numerical control axis according to the corrected positioning data;

[0208] Determining a random error compensation point of the numerical control axis according to the random error data set;

[0209] The position of the random error compensation point is reversely compensated by reverse difference to obtain the target positioning data.

[0210] Optionally, the determining module 20 is used to:

[0211] Determining a systematic error data set of the numerical control axis according to the initial positioning data;

[0212] Using the least square method to perform straight line fitting on the systematic error data set to obtain the straight line fitting result;

[0213] The actual mechanical characteristic parameters are calculated according to the straight line fitting result.

[0214] Optionally, the CNC axis positioning correction and compensation device further includes an evaluation module, which is used to:

[0215] After performing reverse difference compensation on the random error of the numerical control axis according to the correction positioning data, measuring the numerical control axis after reverse difference compensation to obtain a measurement result;

[0216] Determining positioning error data of each measuring point of the numerical control axis according to the measurement result and the target positioning data;

[0217] Evaluating the positioning error data of each measuring point of the CNC axis to obtain an evaluation result;

[0218] If the evaluation result meets the preset error condition, the target positioning data is determined as the final positioning data of the numerical control axis.

[0219] It should be noted that, since the steps executed by the device of this embodiment are the same as the steps of the aforementioned method embodiment, its specific implementation method and the technical effects that can be achieved can refer to the aforementioned embodiment and will not be repeated here.

[0220] In addition, in one embodiment, an embodiment of the present disclosure further provides an electronic device, which includes a processor, a memory, and a computer program stored in the memory, and the computer program implements the steps of the method in the aforementioned embodiment when executed by the processor.

[0221] In addition, in one embodiment, an embodiment of the present disclosure further provides a computer storage medium, on which a computer program is stored, and when the computer program is executed by a processor, the steps of the method in the aforementioned embodiment are implemented.

[0222] In some embodiments, the computer readable storage medium may be a memory such as FRAM, ROM, PROM, EPROM, EEPROM, flash memory, magnetic surface memory, optical disk, or CD-ROM; or various devices including one or any combination of the above memories. The computer may be various computing devices including intelligent terminals and servers.

[0223] In some embodiments, executable instructions may be in the form of a program, software, software module, script or code, written in any form of programming language (including compiled or interpreted languages, or declarative or procedural languages), and may be deployed in any form, including as a stand-alone program or as a module, component, subroutine or other unit suitable for use in a computing environment.

[0224] As an example, executable instructions may, but need not, correspond to a file in a file system, may be stored as part of a file that stores other programs or data, such as in one or more scripts in a HyperText Markup Language (HTML) document, in a single file dedicated to the program in question, or in multiple coordinated files (e.g., files storing one or more modules, subroutines, or code portions).

[0225] By way of example, executable instructions may be deployed to be executed on one computing device, or on multiple computing devices located at one site, or on multiple computing devices distributed across multiple sites and interconnected by a communication network.

[0226] It should be noted that, in this article, the terms "include", "may include" or any other variations thereof are intended to cover non-exclusive inclusions, so that a process, method, article or system including a series of elements includes not only those elements, but also other elements not explicitly listed, or also includes elements inherent to such process, method, article or system. In the absence of further restrictions, an element defined by the sentence "includes a ..." does not exclude the existence of other identical elements in the process, method, article or system including the element.

[0227] The serial numbers of the above-mentioned embodiments of the present disclosure are only for description and do not represent the advantages or disadvantages of the embodiments.

[0228] Through the description of the above implementation methods, those skilled in the art can clearly understand that the above-mentioned embodiment methods can be implemented by means of software plus a necessary general hardware platform, and of course by hardware, but in many cases the former is a better implementation method. Based on such an understanding, the technical solution of the present disclosure, or the part that contributes to the prior art, can be embodied in the form of a software product, which is stored in a storage medium (such as a read-only memory / random access memory, a magnetic disk, or an optical disk), and includes a number of instructions for enabling a multimedia terminal device (which can be a mobile phone, a computer, a television receiver, or a network device, etc.) to execute the methods described in each embodiment of the present disclosure.

[0229] The above descriptions are only optional embodiments of the present disclosure, and are not intended to limit the patent scope of the present disclosure. All equivalent structural transformations made using the contents of the present disclosure and the drawings under the inventive concept of the present disclosure, or direct / indirect applications in other related technical fields are included in the patent protection scope of the present disclosure.

Claims

1. A method for positioning, correction and compensation of a CNC axis, characterized in that: include: Get the initial positioning data of the CNC axis; Determining actual mechanical characteristic parameters of the CNC axis according to the initial positioning data; According to the theoretical mechanical characteristic parameters of the numerical control axis and the actual mechanical characteristic parameters, the systematic positioning error value of the numerical control axis is corrected to obtain the corrected positioning data of the numerical control axis; According to the corrected positioning data, reverse difference compensation is performed on the random error of the numerical control axis to obtain the target positioning data of the numerical control axis.

2. The method according to claim 1, characterized in that The method of correcting the systematic positioning error value of the numerical control axis according to the theoretical mechanical characteristic parameters and the actual mechanical characteristic parameters of the numerical control axis to obtain the corrected positioning data of the numerical control axis includes: Calculating a system theoretical displacement unit and a system actual displacement unit of the numerical control axis according to the theoretical mechanical characteristic parameters and the actual mechanical characteristic parameters; Calculating the theoretical pulse equivalent and the actual pulse equivalent of the numerical control axis according to the theoretical displacement unit of the system and the actual displacement unit of the system; Calculating the theoretical displacement and the actual displacement of the numerical control axis according to the theoretical pulse equivalent and the actual pulse equivalent; Calculating a systematic positioning error value of the numerical control axis according to the actual displacement and the theoretical displacement; The systematic positioning error value is corrected to obtain the corrected positioning data of the numerical control axis.

3. The method according to claim 2, characterized in that The step of correcting the systematic positioning error value to obtain the corrected positioning data of the numerical control axis includes: Determining a proportional function of the pulse command displacement according to the systematic positioning error value; Determine a first functional relationship of the axis systematic positioning error value of the numerical control axis according to the straight line fitting result and the direct proportional function; Determine a second functional relationship corresponding to the system transmission parameter formula of the CNC axis according to the first functional relationship; According to the second functional relationship, determining a systematic error correction functional relationship of the numerical control axis; Based on the systematic error correction function relationship, the systematic positioning error value is corrected to obtain the corrected positioning data.

4. The method according to claim 3, characterized in that The step of correcting the systematic positioning error value based on the systematic error correction function relationship to obtain the corrected positioning data includes: Correcting one or more of the actual speed ratio between the motor encoder and the motor, the actual speed ratio between the motor and the lead screw reducer, and the actual pitch in the systematic error correction function relationship to correct the systematic positioning error value; If the digital control system corresponding to the CNC axis is a semi-closed loop system, the systematic error correction function relationship is expressed as: If the digital control system corresponding to the CNC axis is a fully closed-loop system, the systematic error correction function relationship is expressed as: t=(1+k)*t0 Among them, λ0 is the theoretical speed ratio between the motor encoder and the motor, λ is the actual speed ratio between the motor encoder and the motor, t0 is the theoretical pitch, t is the actual pitch, I0 is the theoretical speed ratio between the motor and the screw reducer, I is the actual speed ratio between the motor and the screw reducer, and k is the proportional coefficient.

5. The method according to claim 1, characterized in that The method of performing reverse difference compensation on the random error of the numerical control axis according to the corrected positioning data to obtain the target positioning data of the numerical control axis includes: Determining a random error data set of the numerical control axis according to the corrected positioning data; Determining a random error compensation point of the numerical control axis according to the random error data set; The position of the random error compensation point is reversely compensated by reverse difference to obtain the target positioning data.

6. The method according to claim 1, characterized in that Determining the actual mechanical characteristic parameters of the CNC axis according to the initial positioning data includes: Determining a systematic error data set of the numerical control axis according to the initial positioning data; Using the least square method to perform straight line fitting on the systematic error data set to obtain the straight line fitting result; The actual mechanical characteristic parameters are calculated according to the straight line fitting result.

7. The method according to claim 1, characterized in that After performing reverse difference compensation on the random error of the numerical control axis according to the corrected positioning data, the method further includes: The CNC axis after reverse difference compensation is measured to obtain the measurement result; Determining positioning error data of each measuring point of the numerical control axis according to the measurement result and the target positioning data; Evaluating the positioning error data of each measuring point of the CNC axis to obtain an evaluation result; If the evaluation result meets the preset error condition, the target positioning data is determined as the final positioning data of the numerical control axis.

8. A CNC axis positioning correction and compensation device, characterized in that: include: An acquisition module is used to acquire the initial positioning data of the CNC axis; A determination module, used to determine actual mechanical characteristic parameters of the CNC axis according to the initial positioning data; A correction module, used for correcting the systematic positioning error value of the numerical control axis according to the theoretical mechanical characteristic parameters of the numerical control axis and the actual mechanical characteristic parameters, so as to obtain the corrected positioning data of the numerical control axis; The compensation module is used to perform reverse difference compensation on the random error of the numerical control axis according to the corrected positioning data to obtain the target positioning data of the numerical control axis.

9. A computer-readable storage medium, characterized in that: The computer-readable storage medium stores a computer program, and the processor executes the computer program to implement the method according to any one of claims 1 to 7.

10. An electronic device, characterized in that: The electronic device comprises a memory and a processor, wherein the memory stores a computer program, and the processor executes the computer program to implement the method according to any one of claims 1 to 7.

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