CN111168246A

CN111168246A - Laser processing method and system for annular object

Info

Publication number: CN111168246A
Application number: CN202010012217.XA
Authority: CN
Inventors: 贺晓娥
Original assignee: BEIJING JCZ TECHNOLOGY CO LTD
Current assignee: BEIJING JCZ TECHNOLOGY CO LTD
Priority date: 2020-01-07
Filing date: 2020-01-07
Publication date: 2020-05-19

Abstract

The invention relates to a laser processing method and a laser processing system for a circular object, wherein the method comprises the following steps: 4 times of frequency multiplication is carried out on the encoder, and in the laser processing process, the distance between pixel points of marking images of circular objects with different diameters is kept unchanged by adjusting the number of pulses collected by the encoder; the circular object is controlled to follow the X axis of the laser in the moving process, so that each pixel point and the pixel point marked for the first time are in the same position when the circular object rotates for one circle, and the repeated precision error is eliminated. The invention can realize that the two-dimensional or three-dimensional graph required by the marking of the pixel points can be adaptively matched regardless of the diameter change of the annular object, whether the annular object adopts a high linear speed encoder or a low linear speed encoder, and whether the annular object rotates at high speed or at low speed.

Description

Laser processing method and system for annular object

Technical Field

The invention belongs to the technical field of laser marking and engraving, and particularly relates to a laser processing method and a laser processing system for a circular object.

Background

The laser engraving machine is used in advertising industry, process industry, mould industry, construction industry, printing and packaging industry, wood industry, decoration industry, leather industry, battery industry and the like, and different industries have circular objects needing laser processing.

The existing laser processing on a circular object has the defects of uneven pixel points of a marked image, low repeated processing precision, high linear speed and high price of a used encoder and the like. The concrete aspects are as follows:

firstly, the maximum of the existing high-linear-speed encoder is 20000 linear speeds, the existing high-linear-speed encoder cannot support the circular object with an overlarge diameter or the circular object with an overlarge pixel point to carry out laser marking, the pixel point interval of the circular object with different diameters cannot be kept unchanged, and the two-dimensional and three-dimensional images can not be engraved by the high-linear-speed encoder under the condition of highly rotating the circular object.

Secondly, the number of pulses per revolution acquired by codes in the laser processing process of the existing annular object is unchanged, and the light emitting frequency of the laser at any position cannot be adaptively adjusted according to the change of the diameter from any position to the circle center on the annular object, so that the distance between marked image pixels is unchanged.

Disclosure of Invention

The invention aims to provide a laser processing method and a laser processing system for a circular object, which can realize that the circular object can be self-adaptively matched with a two-dimensional or three-dimensional graph required by marking of a pixel point regardless of high linear speed encoder or low linear speed encoder (2000 lines) and regardless of high speed rotation or low speed rotation of the object and diameter change of the circular object.

The invention provides a laser processing method for a circular object, which comprises the following steps:

4 times of frequency multiplication is carried out on the encoder, and in the laser processing process, the distance between pixel points of marking images of circular objects with different diameters is kept unchanged by adjusting the number of pulses collected by the encoder;

the circular object is controlled to follow the X axis of the laser in the moving process, so that each pixel point and the pixel point marked for the first time are in the same position when the circular object rotates for one circle, and the repeated precision error is eliminated.

Further, the encoder is a 2000-line encoder.

The invention also provides a laser processing system for the annular object, which comprises a control card, an encoder, a rotary shaft driver, a motor and a laser, wherein the encoder is arranged on the control card;

the encoder is connected with the rotating shaft driver and the motor, and the rotating shaft driver and the motor are connected with the annular object to be processed; the laser is arranged facing the annular object; the control card is connected with the rotating shaft driver, the motor, the encoder and the laser;

the encoder is used for adjusting the number of pulses collected by the encoder after 4 times of frequency multiplication in the laser processing process, so that the distance between pixel points of marked images of circular objects with different diameters is kept unchanged;

the control card is used for controlling the circular object to follow the X axis of the laser in the motion process, so that each pixel point and the pixel point marked for the first time are in the same position when the circular object rotates for one circle, and repeated precision errors are eliminated.

Further, the encoder is a 2000-line encoder.

By means of the scheme, the laser processing method and the laser processing system for the annular object can realize that the two-dimensional or three-dimensional graph required by marking of the pixel points can be matched in a self-adaptive mode no matter whether the annular object adopts a high linear speed encoder or a low linear speed encoder (2000 lines) or whether the annular object rotates at a high speed or at a low speed, and no matter how the diameter of the annular object changes.

The foregoing description is only an overview of the technical solutions of the present invention, and in order to make the technical solutions of the present invention more clearly understood and to implement them in accordance with the contents of the description, the following detailed description is given with reference to the preferred embodiments of the present invention and the accompanying drawings.

Drawings

FIG. 1 is a schematic diagram of a laser processing system for a ring-shaped object according to the present invention;

FIG. 2 is an encoder signal and a laser signal of the present invention;

FIG. 3 is a timing diagram of an incremental encoder of the present invention;

FIG. 4 is a waveform diagram of an encoder output of the present invention;

fig. 5 is a diagram of the quadruple subdivision circuit of the present invention.

Reference numbers in the figures:

1-a control card; 2-an encoder; 3-rotating shaft driver and motor; 4-a circular ring-shaped object; 5-a laser; 6-Z axis; 7-X axis.

Detailed Description

The following detailed description of embodiments of the present invention is provided in connection with the accompanying drawings and examples. The following examples are intended to illustrate the invention but are not intended to limit the scope of the invention.

The embodiment provides a laser processing method for a circular object, which comprises the following steps:

By the laser processing method for the annular object, the two-dimensional or three-dimensional graph required by pixel point marking can be matched in a self-adaptive manner no matter the annular object adopts a high linear speed encoder or a low linear speed encoder, and no matter the object rotates at a high speed or at a low speed, no matter how the diameter of the annular object changes. Can be used in printing plate roller industry, automobile tire industry, energy manufacturing industry and the like.

Referring to fig. 1, a laser processing system for a circular object is further provided, which includes a control card 1, an encoder 2, a rotary shaft driver and motor 3, and a laser 5;

the encoder 2 is connected with a rotating shaft driver and a motor 3, and the rotating shaft driver and the motor 3 are connected with a circular object 4 to be processed; the laser 5 is arranged facing the annular object 4; the control card 1 is connected with a rotating shaft driver and motor 3, an encoder 2 and a laser 5;

the encoder 2 is used for adjusting the number of pulses collected by the encoder 2 after 4 times of frequency multiplication in the laser processing process, so that the distance between pixel points of marked images of annular objects 4 with different diameters is kept unchanged;

the control card 1 is used for controlling the circular object 4 to follow the X axis of the laser in the motion process, so that each pixel point and the pixel point marked for the first time are in the same position when the circular object 4 rotates for one circle, and the repeated precision error is eliminated.

Through this a laser beam machining system for ring form object, can realize no matter the ring form object adopts high linear speed encoder or low linear speed encoder, no matter be the object high speed rotatory or the low speed is rotatory, no matter how the ring form object diameter changes can both the self-adaptation match pixel point mark required two-dimentional or three-dimensional figure.

The present invention is described in further detail below.

Referring to fig. 1, the encoder 2 may use a 2000-line encoder to process different data after 4 times of frequency multiplication, for example, a picture with 800 pixels marked on a circular object with a diameter of d1, wherein 10 pulses give out primary light on average, and the dot spacing is uniform; 8000 pixel points are marked on a circular object with the same diameter of d1, and secondary light is generated by 1 pulse on average, and the distance between the points is uniform; if 3000 pixels are marked on a circular object with the same diameter, in the prior art, 3 pulses may be used for one shot or 2 pulses may be used for emitting secondary light, but the distance between the marked points is not uniform, and the distance between the marked points can be uniform through the interpolation algorithm. The encoder 2 is controlled by 20000 linear speed due to the highest precision made by hardware defects, and if the pixel points needing to be marked are larger than 20000 linear speed, the uniform distance between the marked pixel points cannot be ensured, so that the problem of non-uniform marked pixel points can be solved by the method.

The control card 1 controls the circular object 4 to follow the Laser X axis back and forth in the movement process according to the control algorithm, so that each pixel point and the pixel point marked for the first time are located at the same position every time the circular object 4 rotates for one circle, the theoretical error of the repetition precision is 0, and as shown in fig. 2, an encoder signal and a Laser (Laser) light emitting signal are obtained. The laser signal indicates light once per high level.

Encoder pulse counting:

pulse detection is the detection of the rising edge, and the incremental encoder timing is shown in FIG. 3:

the FPGA acquires a rising edge, and under the condition that no inversion occurs, the phase relation of the encoder is as follows:

a + 0 degree

B +90 degree

A-180 degree

B-270 degrees.

Thus, four rising edges are detected respectively to achieve quadruple frequency.

Referring to fig. 4, a + advances B +90 degrees in the forward rotation of the encoder, and B + is high at the falling edge of a +. When the encoder is reversed, a + lags behind B +90 degrees, and at the falling edge of a +, B + is low. Thus, the encoder rotation direction can be determined by determining the level state of B + at the falling edge of a + when the encoder is rotated.

According to the output of the incremental photoelectric encoder, in one output period, the two paths of output signals of the A phase and the B phase generate 4 jumping edges, and if the jumping edges can be captured and counted, the resolution of the encoder can be improved by 4 times. As shown in fig. 5, a2 and B2 respectively lag behind a1 and B1 by one clock cycle, while B1 and B2 respectively delay a1 and a2 by 90 degrees, and after passing through 2 exclusive or gates or 1 or gate, the frequency of the signal P is 4 times that of the a-phase (or B-phase) signal, so that 4 times of subdivision can be realized as long as the CLK clock frequency is 4 times or more greater than the frequency of the a-phase (or B-phase) signal.

The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention, it should be noted that, for those skilled in the art, many modifications and variations can be made without departing from the technical principle of the present invention, and these modifications and variations should also be regarded as the protection scope of the present invention.

Claims

1. A laser processing method for a ring-shaped object, comprising:

2. The laser processing method for a ring-shaped object according to claim 1, wherein the encoder is a 2000-line encoder.

3. A laser processing system for a circular object is characterized by comprising a control card, an encoder, a rotary shaft driver, a motor and a laser;

4. The laser machining system of claim 3, wherein the encoder is a 2000 line encoder.