A method for processing position overflow of absolute value encoding of rotary table

Abstract

The present application relates to the field of automation control technology, and in particular to a method for processing the position overflow of the absolute value encoding of a rotary table, comprising: collecting the reduction ratio of the reducer transmission design used by the rotary table and the resolution of the absolute value servo encoder; setting the command pulse equivalent of the control system so that when the rotary table rotates one circle, the change amount of the encoder feedback pulse counter of the absolute value servo feedback is 2 n , where n is a positive integer less than 31; the electronic gear ratio of the absolute servo drive is calculated according to the reduction ratio, the resolution and the command pulse equivalent. The present application solves the problem of coordinate confusion caused by overflow of the absolute encoder by setting a suitable electronic gear ratio and system command pulse equivalent. At the same time, the absolute servo drive does not need to support the absolute position rotation mode function, nor does it need to specifically set the reduction ratio of the reducer or the upper limit value of the absolute value multi-turn.

Description

Technical Field

[0001] The present application relates to the field of automation control technology, and in particular to a method for processing an absolute value encoding position overflow of a rotary table. Background Art

[0002] In the field of automation control technology, the rotary table is an important mechanical equipment and is widely used in various production lines and processing equipment. The rotary table generally adopts a reducer transmission design. The reduction ratio of the reducer is a:b, and its ratio is not equal to 2. n In order to ensure the precise control and positioning of the rotary table, an absolute servo drive is usually used for driving. The absolute servo drive has a power-off memory function, that is, when the power is turned on again after a power outage, the previous absolute position information can be maintained, thereby ensuring the continuity and accuracy of the equipment.

[0003] However, when using an absolute servo on a rotary table that rotates in one direction, there is a technical defect: the absolute encoder overflows. Specifically, the absolute encoder is a key component in the servo drive, used to feedback the rotation position and speed information of the motor. It usually uses a 4-byte signed int type data to represent the value of the feedback pulse counter. The range of this value is limited to ±2 31 When the rotary table continues to rotate in one direction, the feedback pulse counter of the absolute encoder will continue to accumulate, and the counter value will exceed the maximum value +2 31 When the absolute encoder overflows, it is called an absolute encoder overflow. Absolute encoder overflow can cause a problem: before and after the overflow, the absolute encoder feedback pulse counter multiplied by the control system command pulse equivalent to obtain the angle coordinate value and then modulo 360°, which may cause uncertain jumps. This means that after the absolute encoder overflows, the control system may not be able to accurately know the actual position of the rotary table, resulting in coordinate confusion.

[0004] The existing technology solves this problem by setting the absolute position rotation mode or setting the reduction ratio a:b of the reducer or the absolute value multi-turn upper limit a, but it requires the absolute value drive to support the absolute position rotation mode function and needs to set specific parameters, which is not only economically expensive, but also may limit the motion range or performance of the rotary table. Therefore, how to solve this problem without the absolute value servo drive supporting the absolute position rotation mode function and without setting specific parameters is an urgent problem to be solved. Summary of the invention

[0005] The present application provides a method for processing the absolute value encoding position overflow of a rotary table, aiming to solve the problem of coordinate confusion caused by the overflow of the absolute value encoder. At the same time, there is no need for the absolute value servo drive to support the absolute position rotation mode function, nor is there a need to set specific parameters.

[0006] In order to achieve the above object, the present invention adopts the following technical scheme:

[0007] In a first aspect, the present invention provides a method for processing an absolute value encoding position overflow of a rotary table, the method comprising:

[0008] Collect the reduction ratio of the reducer transmission design used in the rotary table and the resolution of the absolute servo encoder;

[0009] Set the command pulse equivalent of the control system so that when the rotary table rotates one circle, the change in the encoder feedback pulse counter of the absolute value servo feedback is 2 n , where n is a positive integer less than 31;

[0010] The electronic gear ratio of the absolute value servo drive is calculated according to the reduction ratio, the resolution and the command pulse equivalent;

[0011] Collect the encoder feedback pulse counter data of the absolute value servo motor. When the encoder feedback pulse counter data overflows, calculate the angular coordinates of the rotary table according to the electronic gear ratio and the command pulse equivalent, use the angular coordinates as the actual coordinates of the rotary table, and send them to the control system.

[0012] In a preferred example of the present application, it can be further set that the value of the command pulse equivalent is obtained by setting the system lead to 360° and the corresponding pulse number of the system to 2 c To determine, 31>c>8, c is a positive integer.

[0013] In a preferred example of the present application, it can be further configured to include:

[0014] The calculation method of the electronic gear ratio is determined based on the relationship between the number of command pulses sent by the control system to the driver of the absolute value servo motor when the rotary table rotates one circle and the number of circles rotated by the absolute value servo motor.

[0015] In a preferred example of the present application, it can be further configured that the calculation method of determining the electronic gear ratio based on the relationship between the number of command pulses sent by the control system to the servo driver and the number of revolutions of the absolute value servo motor when the rotary table rotates one circle includes:

[0016] Determine that the angle of rotation of the rotary table is 360° and the resolution of the encoder of the absolute servo motor is 2 m , m is the number of encoder bits;

[0017] The numerator and denominator of the electronic gear ratio are calculated according to the reduction ratio, the resolution and the value of the command pulse equivalent.

[0018] In a preferred example of the present application, it can be further configured to include:

[0019] The value range of c is determined based on the value ranges of the numerator and denominator of the electronic gear ratio.

[0020] In a preferred example of the present application, it can be further set that c is the number of bits of the encoder of the absolute servo motor.

[0021] In a second aspect, the present application provides a device for processing an absolute value encoding position overflow of a rotary table, the device comprising:

[0022] The data acquisition module is used to collect the reduction ratio of the reducer transmission design used in the rotary table and the resolution of the absolute servo encoder;

[0023] The command pulse equivalent module is used to set the command pulse equivalent of the control system so that when the rotary table rotates one circle, the change in the motor encoder feedback pulse counter of the absolute value servo feedback is 2 n , where n is a positive integer less than 31;

[0024] An electronic gear ratio module, used for calculating the electronic gear ratio of the absolute value servo drive according to the reduction ratio, the resolution and the command pulse equivalent;

[0025] The control module is used to collect the encoder feedback pulse counter data of the absolute value servo driver. When the encoder feedback pulse counter data overflows, the angular coordinates of the rotary table are calculated according to the electronic gear ratio and the command pulse equivalent, and the angular coordinates are used as the actual coordinates of the rotary table and sent to the control system.

[0026] In a third aspect, the present application provides a computer device comprising a memory, a processor, and a computer program stored in the memory and executable on the processor, wherein when the processor executes the computer program, the processor implements the steps of a method for processing the absolute value encoding position overflow of a rotary table as described in any one of the above items.

[0027] In a fourth aspect, the present application provides a computer-readable storage medium having a program stored thereon, wherein when the program is executed by a processor, a method for processing an absolute value encoding position overflow of a rotary table as described in any one of the above items is implemented.

[0028] In a fifth aspect, the present application provides a computer program product, comprising computer instructions, which, when executed by a processor, implement the steps of a method for processing an absolute value encoding position overflow of a rotary table as described in any one of the above items.

[0029] In summary, compared with the prior art, the technical solution provided in the embodiment of the present application has at least the following beneficial effects:

[0030] 1. This application solves the problem of coordinate confusion caused by absolute encoder overflow by setting a suitable electronic gear ratio and system command pulse equivalent. At the same time, it does not require the absolute servo driver to support the absolute position rotation mode function, nor does it require specific settings for the reduction ratio of the reducer or the absolute value multi-turn limit value. Specifically, when the motor encoder feedback pulse counter of the absolute servo feedback overflows, its count value ±2 31 Just enough to be 2 n (n<31) is divided by the absolute value encoder feedback pulse counter before and after the overflow, multiplied by the control system command pulse equivalent to obtain the angle coordinate value and then 360°

[0031] After taking the module, it has continuity, or a jump between 0° and 360°, so that the coordinate value of the absolute servo feedback is consistent with the actual physical position, improving the stability and reliability of the motor and rotary table application.

[0032] 2. Since there is no need to set the reduction ratio a:b for the reducer of the absolute value servo drive, or set the upper limit parameters of the absolute value multi-turn number, the operation process is simplified and the use of the motor is more efficient.

[0033] 3. This application is applicable to all absolute servo drives with complete absolute encoder feedback pulse counter function and has wide application. BRIEF DESCRIPTION OF THE DRAWINGS

[0034] Figure 1 A flowchart of a method for processing absolute value encoding position overflow of a rotary table provided in one embodiment of the present application.

[0035] Figure 2 A structural diagram of a device for processing absolute value encoding position overflow of a rotary table provided in one embodiment of the present application. DETAILED DESCRIPTION

[0036] The following will be combined with the drawings in the embodiments of the present application to clearly and completely describe the technical solutions in the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, not all of the embodiments. Based on the embodiments in the present application, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of this application.

[0037] In one embodiment of the present application, a method for processing the position overflow of the absolute value encoding of a rotary table is provided. Figure 1 As shown, the method includes:

[0038] S100: Collect the reduction ratio of the reducer transmission design used in the rotary table and the resolution of the absolute servo encoder;

[0039] S200: Set the command pulse equivalent of the control system so that when the rotary table rotates one circle, the change in the encoder feedback pulse counter of the absolute servo feedback is 2 n , where n is a positive integer less than 31;

[0040] Specifically, set the parameters first, including:

[0041] Screw lead: the angle of one rotation of the worktable, the value is 360°;

[0042] Number of pulses per motor revolution: The resolution of the absolute value motor encoder. Taking a 23-bit encoder as an example, the value is 2 23 ;

[0043] System lead, number of pulses per revolution: used to express the command pulse equivalent of the control system;

[0044] Mechanical end reduction ratio, motor end reduction ratio: used to express the reduction ratio of the transmission mechanism reducer from the absolute value servo motor to the rotary table;

[0045] Electronic gear ratio numerator and electronic gear ratio denominator: used for the conversion ratio coefficient between the servo drive command pulse and feedback pulse.

[0046] Next, determine the expression of the command pulse equivalent of the control system, which is:

[0047]

[0048] In the above formula, two variables are used to describe the command pulse equivalent of the control system, the purpose of which is to describe the situation of an infinite non-repeating decimal that cannot be divided evenly.

[0049] S300: Calculating the electronic gear ratio of the absolute value servo drive according to the reduction ratio, the resolution and the command pulse equivalent;

[0050] Specifically, according to the value of the command pulse equivalent, the reduction ratio and the resolution determined in S200, the electronic gear ratio of the absolute value servo drive is calculated.

[0051] First, the values ​​of various parameters are taken, including: the system lead is taken as the angle of the rotary table rotating one circle, which is 360°; the corresponding pulse number of the system is taken as an integer multiple of 2, that is, 2 c (31>c>8), c=23, that is, the value is 2 23 ; The absolute value servo driver sets the reduction ratio of the reducer to a:b (a>b). Assume that the motor end rotates a circles and the mechanical end rotates b circles. The value of a is 61 and the value of b is 3.

[0052] The expression that determines the relationship between the number of pulses fed back by the encoder and the electronic gear is:

[0053]

[0054]

[0055] According to formula (2), calculate the numerator and denominator of the electronic gear ratio.

[0056] According to the above preset formula, the number of command pulses sent by the control system to the servo driver when the rotary table rotates one circle (360°) is the number of command pulses received by the servo driver, which can be obtained as follows:

[0057]

[0058] Next, substitute formula (1) into formula (4) to obtain:

[0059]

[0060] Servo drive command pulse number = 2 c (31>c>8)=2 23 (take c = 23); (6)

[0061] Therefore, when the rotary table rotates one circle, the number of circles the servo motor rotates is:

[0062]

[0063] The expression of the number of pulses fed back by the encoder when the rotary table rotates one circle is:

[0064]

[0065] (take a=61,b=3,encoder resolution=2 23 );(9)

[0066] Finally, combining formulas (3), (6), and (9), we can obtain:

[0067]

[0068] In the values ​​of this embodiment, the gear ratio is

[0069] S400: Collect the encoder feedback pulse counter data of the absolute value servo motor. When the encoder feedback pulse counter data overflows, calculate the angular coordinates of the rotary table according to the electronic gear ratio and the command pulse equivalent, use the angular coordinates as the actual coordinates of the rotary table, and send them to the control system.

[0070] Specifically, according to the periodic repeatability of the rotation of the rotary table, the calculation formula of the angle coordinate of the rotary table is:

[0071]

[0072] The angle coordinates are used as the actual coordinates of the rotary table, that is, the coordinates corresponding to the angle coordinates of the rotary table and the physical position, and are sent to the control system.

[0073] In this embodiment, the beneficial effects include at least:

[0074] 1. This application solves the problem of coordinate confusion caused by absolute encoder overflow by setting a suitable electronic gear ratio and system command pulse equivalent. At the same time, it does not require the absolute servo driver to support the absolute position rotation mode function, nor does it require specific settings for the reduction ratio of the reducer or the absolute value multi-turn limit value. Specifically, when the motor encoder feedback pulse counter of the absolute servo feedback overflows, its count value ±2 31 Just enough to be 2 n (n<31), the absolute encoder feedback pulse counter before and after the overflow is multiplied by the control system command pulse equivalent to obtain the angle coordinate value, and then modulo 360°, which has continuity, so that the coordinate value of the absolute servo feedback is consistent with the actual physical position, improving the stability and reliability of the motor and rotary table application. According to the closed-loop characteristics of the servo drive, the number of motor encoder feedback pulses (command units) of the absolute servo feedback must be equal to the number of command pulses sent by the control system.

[0075] 2. Since there is no need to set the reduction ratio a:b for the reducer of the absolute value servo drive, or set the upper limit parameters of the absolute value multi-turn number, the operation process is simplified and the use of the motor is more efficient.

[0076] 3. This application is applicable to all absolute servo drives with complete absolute encoder feedback pulse counter function and has wide application.

[0077] In some embodiments, including:

[0078] The value range of b is determined based on the value ranges of the numerator and denominator of the electronic gear ratio.

[0079] Furthermore, the value of b is the number of bits of the encoder of the absolute servo motor.

[0080] In this embodiment, the accuracy of determining the angle coordinates is improved.

[0081] This application also provides a processing device for the absolute value encoding position overflow of the rotary table, please refer to Figure 2 As shown, the device comprises:

[0082] The data acquisition module 100 is used to collect the reduction ratio of the reducer transmission design used in the rotary table and the resolution of the absolute servo encoder;

[0083] The command pulse equivalent module 200 is used to set the command pulse equivalent of the control system so that when the rotary table rotates one circle, the change amount of the motor encoder feedback pulse counter of the absolute value servo feedback is 2 n , where n is a positive integer less than 31;

[0084] An electronic gear ratio module 300, used for calculating the electronic gear ratio of the absolute value servo drive according to the reduction ratio, the resolution and the command pulse equivalent;

[0085] The control module 400 is used to collect the encoder feedback pulse counter data of the absolute value servo drive. When the encoder feedback pulse counter data overflows, the angular coordinates of the rotary table are calculated according to the electronic gear ratio and the instruction pulse equivalent, and the angular coordinates are used as the actual coordinates of the rotary table and sent to the control system.

[0086] The functional implementation of each module in the above-mentioned rotary table absolute value encoding position overflow processing device corresponds to the steps in the above-mentioned rotary table absolute value encoding position overflow processing method embodiment, and its functions and implementation processes will not be repeated here one by one.

[0087] The present application also provides a computer device, including a memory, a processor, and a computer program stored in the memory and executable on the processor, wherein when the processor executes the computer program, the steps of the method for processing the absolute value encoding position overflow of the rotary table as described in any of the above embodiments are implemented.

[0088] The present application also provides a computer-readable storage medium, on which a program is stored, wherein the computer-readable storage medium refers to a carrier for storing data, which may include but is not limited to a floppy disk, an optical disk, a hard disk, a flash memory, a USB flash drive and / or a memory stick, etc., and the computer may be a general-purpose computer, a special-purpose computer, a computer network, or other programmable devices. The working process, working details and technical effects of the computer-readable storage medium provided in this embodiment can be found in the above embodiment of a method for processing the position overflow of the absolute value encoding of a rotary table, which will not be repeated here.

[0089] The application also provides a computer program product, including computer instructions, which, when executed by a processor, implement the steps of the method for processing the absolute value encoding position overflow of the rotary table as described in any of the above embodiments.

[0090] Those skilled in the art can understand that all or part of the processes in the above-mentioned embodiment methods can be completed by instructing the relevant hardware through a computer program, and the computer program can be stored in a non-volatile computer-readable storage medium. When the computer program is executed, it can include the processes of the embodiments of the above-mentioned methods. Among them, any reference to memory, storage, database or other media used in the embodiments provided in the present application can include non-volatile and / or volatile memory. Non-volatile memory can include read-only memory (ROM), programmable ROM (PROM), electrically programmable ROM (EPROM), electrically erasable programmable ROM (EEPROM) or flash memory. Volatile memory can include random access memory (RAM) or external cache memory. As an illustration and not limitation, RAM is available in many forms, such as static RAM (SRAM), dynamic RAM (DRAM), synchronous DRAM (SDRAM), double data rate SDRAM (DDRSDRAM), enhanced SDRAM (ESDRAM), synchronous link (Synchlink) DRAM (SLDRAM), memory bus (Rambus) direct RAM (RDRAM), direct memory bus dynamic RAM (DRDRAM), and memory bus dynamic RAM (RDRAM).

[0091] The technical features of the above embodiments can be combined arbitrarily. In order to make the description concise, all possible combinations of the technical features in the above embodiments are not described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification. The above-mentioned embodiments only express several implementation methods of the present application, and their descriptions are relatively specific and detailed, but they cannot be understood as limiting the scope of the invention patent. It should be pointed out that for ordinary technicians in this field, without departing from the concept of the present application, several deformations and improvements can be made, which all belong to the protection scope of the present application. Therefore, the protection scope of the patent of this application shall be based on the attached claims.

Claims

1. A method for processing the position overflow of the absolute value encoding of a rotary table, characterized in that: include: Collect the reduction ratio of the reducer transmission design used in the rotary table and the resolution of the absolute servo encoder; Set the command pulse equivalent of the control system so that when the rotary table rotates one circle, the change in the encoder feedback pulse counter of the absolute value servo feedback is 2 n , where n is a positive integer less than 31; The electronic gear ratio of the absolute value servo drive is calculated according to the reduction ratio, the resolution and the command pulse equivalent; Collect the encoder feedback pulse counter data of the absolute value servo motor. When the encoder feedback pulse counter data overflows, calculate the angular coordinates of the rotary table according to the electronic gear ratio and the command pulse equivalent, use the angular coordinates as the actual coordinates of the rotary table, and send them to the control system.

2. The method for processing the position overflow of the absolute value encoding of the rotary table according to claim 1, characterized in that: The value of the command pulse equivalent is determined by setting the system lead to 360° and the corresponding pulse number to 2. c To determine, 31>c>8, c is a positive integer.

3. The method for processing the position overflow of the absolute value encoding of the rotary table according to claim 2, characterized in that: include: The calculation method of the electronic gear ratio is determined based on the relationship between the number of command pulses sent by the control system to the driver of the absolute value servo motor when the rotary table rotates one circle and the number of circles rotated by the absolute value servo motor.

4. The method for processing the position overflow of the absolute value encoding of the rotary table according to claim 3 is characterized in that: The method for calculating the electronic gear ratio based on the relationship between the number of command pulses sent by the control system to the servo driver and the number of revolutions of the absolute value servo motor when the rotary table rotates one revolution includes: Determine that the angle of rotation of the rotary table is 360° and the resolution of the encoder of the absolute servo motor is 2 m , m is the number of encoder bits; The numerator and denominator of the electronic gear ratio are calculated according to the reduction ratio, the resolution and the value of the command pulse equivalent.

5. The method for processing the position overflow of the absolute value encoding of the rotary table according to claim 4, characterized in that: include: The value range of c is determined based on the value ranges of the numerator and denominator of the electronic gear ratio.

6. The method for processing the position overflow of the absolute value encoding of the rotary table according to claim 5, characterized in that: The value of c is the number of bits of the encoder of the absolute servo motor.

7. A device for processing position overflow of absolute value encoding of a rotary table, characterized in that: include: The data acquisition module is used to collect the reduction ratio of the reducer transmission design used in the rotary table and the resolution of the absolute servo encoder; The command pulse equivalent module is used to set the command pulse equivalent of the control system so that when the rotary table rotates one circle, the change in the motor encoder feedback pulse counter of the absolute value servo feedback is 2 n , where n is a positive integer less than 31; An electronic gear ratio module, used for calculating the electronic gear ratio of the absolute value servo drive according to the reduction ratio, the resolution and the command pulse equivalent; The control module is used to collect the encoder feedback pulse counter data of the absolute value servo driver. When the encoder feedback pulse counter data overflows, the angular coordinates of the rotary table are calculated according to the electronic gear ratio and the command pulse equivalent, and the angular coordinates are used as the actual coordinates of the rotary table and sent to the control system.

8. A computer device comprising a memory, a processor and a computer program stored in the memory and executable on the processor, characterized in that: When the processor executes the computer program, the steps of the method for processing the absolute value encoding position overflow of the rotary table according to any one of claims 1 to 6 are implemented.

9. A computer-readable storage medium, characterized in that: The computer-readable storage medium stores a program, wherein when the program is executed by a processor, the method for processing the absolute value encoding position overflow of the rotary table according to any one of claims 1 to 6 is implemented.

10. A computer program product comprising computer instructions, characterized in that: When executed by a processor, the computer instructions implement the steps of the method for processing the absolute value encoding position overflow of the rotary table as described in claims 1 to 6.

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