A mobile laser engraving machine

Abstract

The present application provides a mobile laser engraving machine, which includes a machine body and a three-axis omnidirectional moving frame arranged at the bottom of the machine body. The three-axis omnidirectional moving frame includes three omnidirectional wheel assemblies evenly distributed along the circumferential direction of the machine body. The omnidirectional wheel assemblies are configured to be able to roll along the wheel axis direction and perpendicular to the wheel axis direction. The three omnidirectional wheel assemblies are independent of each other and can cooperate with each other to achieve the omnidirectional movement of the machine body. Through this mobile laser engraving machine, the limitation of the traditional engraving machine frame can be broken through, the function of large-format engraving and drawing can be realized, and the fuselage is small and easy to carry.

Description

Technical Field

[0001] The present invention relates to the technical field of laser engraving equipment, and more specifically, to a mobile laser engraver. Background Art

[0002] Laser engraving is an important technical means to improve processing efficiency and can be applied to the handicraft gift industry, decoration industry, packaging and printing industry, etc. Compared with the traditional manual engraving process, laser engravers are more intelligent and precise. Currently, most engravers on the market are desktop-based, with a fixed engraving area and a high-precision system control. However, with the change of engraving requirements, the selection of the corresponding engraver also changes. The larger the engraving area, the larger the volume of the engraver to be selected, which generally corresponds to the use of industrial-grade engravers. But for the selection of ordinary users, there is currently a lack of large-area engravers for ordinary users on the market. The selection of industrial-grade engravers is neither portable nor practical.

[0003] At the same time, in the design and development of engravers, designs similar to the ACSYS engraver can achieve large-format engraving of 2900mm×1000mm. In other laser processing industries, the Epilog laser engraver belongs to the CO 2 laser machine series, which can achieve large-area engraving of 1016mm×771mm, and another universal laser engraver can achieve high-precision engraving skills, and also has rich experience in the research and development control of the CO 2 laser engraving system. In domestic research, changes to the control system have been proposed many times. To achieve a stable and reliable single-machine control system for laser engravers, various control schemes for the laser engraver system have been proposed in terms of control system performance. At the same time, in terms of large-area engraving, using energy transmission fibers as a new light path, a software and hardware design for constructing large-format engraving has been proposed.

[0004] It can be seen that the development of laser engravers is rapid and the system iteration and upgrade are fast. However, the current design of laser engravers is all upgraded technically, and there is no in-depth change in the engraving area and portability. The bulkiness of the machine and the complexity of the system make it inconvenient for users to operate and use. Summary of the Invention

[0005] In view of the above problems in the prior art, the present application proposes a mobile laser engraver, which solves the problem of limited engraving area by using an omnidirectional movement design, and the body is small and portable, allowing engraving to be carried out anytime and anywhere.

[0006] The present application provides a mobile laser engraving machine, which includes a machine body and a three-axis omnidirectional moving frame arranged at the bottom of the machine body. The three-axis omnidirectional moving frame includes three omnidirectional wheel assemblies evenly distributed along the circumferential direction of the machine body. The omnidirectional wheel assemblies are configured to be able to roll along the wheel axis direction and perpendicular to the wheel axis direction. The three omnidirectional wheel assemblies are independent of each other and can cooperate with each other to achieve the omnidirectional movement of the machine body. With this mobile laser engraving machine, the limitation of the traditional engraving machine frame can be broken through, the function of large-format engraving and drawing can be realized, and the fuselage is small and easy to carry.

[0007] In a possible implementation manner, the omnidirectional wheel assembly includes a plurality of omnidirectional wheels stacked in parallel. The omnidirectional wheel includes an omnidirectional wheel body and a plurality of rolling members that are independent of each other along the circumferential direction and are freely sleeved on the omnidirectional wheel body.

[0008] In a possible implementation manner, the three-axis omnidirectional moving frame further includes a stepping motor corresponding to each omnidirectional wheel assembly one by one. Through this implementation manner, since the controllable angular displacement of the stepping motor cannot be achieved by a DC motor, the stepping motor can calculate the displacement of a single wheel by using the number of pulses and the wheel diameter.

[0009] In a possible implementation manner, the included angle between the wheel surfaces of two adjacent omnidirectional wheel assemblies is 60°.

[0010] In a possible implementation manner, the rolling linear velocity of each omnidirectional wheel assembly along the direction perpendicular to the wheel axis is determined by the following formula:

[0011]

[0012] Wherein, Va, Vb, and Vc are respectively the rolling linear velocities of the three omnidirectional wheel assemblies along the direction perpendicular to the wheel axis, ψ is the included angle between the wheel surfaces, ω is the spin angular velocity of the machine body, R is the distance from the center of the omnidirectional wheel assembly to the center of the chassis of the machine body, and Vx and Vy are respectively the moving linear velocities of the machine body in the x-axis direction and the y-axis direction.

[0013] In a possible implementation manner, a control system is further arranged inside the machine body, which is used to receive the engraving instruction sent by the host computer and control the movement of the three omnidirectional wheel assemblies and the engraving action of the machine body according to the engraving instruction.

[0014] In a possible implementation manner, the mobile laser engraving machine further includes two wire-pulling type position sensors, which cooperate with each other to achieve the positioning of the machine body. Through this implementation manner, triangular positioning can be realized by using the wire-pulling type position sensors, and the distance information is returned to the host computer for drawing display, intuitively reflecting the engraving process.

[0015] In a possible implementation, the cable-pulling type positioning sensor includes a grating encoder. The two grating encoders are respectively connected to the body through the cables, so as to form a triangular layout with the body, and the positioning of the body is realized by calculating the cable distances from the body to the two grating encoders.

[0016] In a possible implementation, the grating encoder includes: a synchronous pulley around which the cable is wound to rotate under the drive of the cable; a grating code disk fixedly arranged on the top of the synchronous pulley and capable of rotating with the rotation of the synchronous pulley; and a photoelectric pair tube oppositely arranged on both sides of the grating code disk, and the rotation of the grating code disk can periodically cut off the light transmission of the photoelectric pair tube.

[0017] In a possible implementation, the cable-pulling type positioning sensor further includes a cable box for storing the cable.

[0018] The mobile laser engraving machine provided by the present application has the following technical effects compared with the prior art:

[0019] 1) By arranging a three-axis omnidirectional moving frame at the bottom of the engraving machine body, the independent movement of the three omnidirectional wheel assemblies can be controlled according to the received engraving instructions, so as to realize the omnidirectional movement of the body, increase the engraving area, and the body is small and portable, enabling engraving anytime and anywhere.

[0020] 2) A new type of cable positioning sensor is designed. Instead of using a communication device for positioning, ranging is realized by using a cable, and a self-made software is combined with triangulation technology to draw an engraving trajectory for observing the engraving effect.

[0021] The above technical features can be combined in various suitable ways or replaced by equivalent technical features as long as the purpose of the present invention can be achieved. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] Hereinafter, the present invention will be described in more detail based on embodiments and with reference to the drawings, wherein:

[0023] Figure 1 and Figure 2 respectively show a top view schematic diagram and a side view schematic diagram of a mobile laser engraving machine according to an embodiment of the present invention;

[0024] Figure 3 shows a schematic structural diagram of an omnidirectional wheel assembly according to an embodiment of the present invention;

[0025] Figure 4 shows a schematic structural diagram of an omnidirectional wheel according to an embodiment of the present invention;

[0026] Figure 5 Shows the schematic diagram of the three-axis omnidirectional movement according to an embodiment of the present invention;

[0027] Figure 6 Shows the structural schematic diagram of the grating encoder according to an embodiment of the present invention;

[0028] Figure 7 Shows the A-phase and B-phase pulse waveform diagrams output by the grating encoder according to an embodiment of the present invention;

[0029] Figure 8 Shows the schematic diagram of the triangulation positioning according to an embodiment of the present invention;

[0030] Figure 9 Shows the schematic flowchart of the steps of engraving by the mobile laser engraving machine according to an embodiment of the present invention.

[0031] In the drawings, the same components are denoted by the same reference numerals. The drawings are not drawn to actual scale.

[0032] List of reference numerals:

[0033] 100 - Body; 200 - Three-axis omnidirectional movement frame; 211 - First omnidirectional wheel assembly; 212 - Second omnidirectional wheel assembly; 213 - Third omnidirectional wheel assembly; 221 - First stepper motor; 222 - Second stepper motor; 214 - Omnidirectional wheel; 215 - Rolling element; 216 - Omnidirectional wheel body; 217 - Notch; 300 - Cable-pulling type position sensor; 310 - Grating encoder; 311 - Synchronous pulley; 312 - Grating code disk; 313 - Photoelectric pair tube. Detailed implementation manners

[0034] The present invention will be further described below in conjunction with the drawings.

[0035] Figure 1 And Figure 2 is the structural schematic diagram of the mobile laser engraving machine provided by the present application. As Figure 1 And Figure 2 shown, the mobile laser engraving machine includes a body 100, a three-axis omnidirectional movement frame 200 provided at the bottom of the body 100, and a laser engraving cutter head (not shown) provided at the bottom of the body 100; the three-axis omnidirectional movement frame 200 carries the body 100 and drives the body 100 to move omnidirectionally on the engraving surface, increasing the area of the engraving area. Specifically, the three-axis omnidirectional movement frame 200 includes three omnidirectional wheel assemblies uniformly distributed around the body along the circumferential direction, namely the first omnidirectional wheel assembly 211, the second omnidirectional wheel assembly 212, and the third omnidirectional wheel assembly 213, and a stepper motor corresponding to each omnidirectional wheel assembly one by one (in Figure 2Only the first stepping motor 221 and the second stepping motor 222 are shown (), and each omnidirectional wheel assembly is fixedly arranged on the output shaft of the corresponding stepping motor so as to roll along a direction perpendicular to the output shaft (i.e., the wheel axis), that is, roll along the Va, Vb, and Vc directions (described in detail later).

[0036] In addition, in order to achieve the omnidirectional movement of the body 100, the omnidirectional wheel assembly provided in this application can roll along the direction of the output shaft in addition to being able to roll along a direction perpendicular to the wheel axis as described above. Specifically, as Figure 3 shown, taking the first omnidirectional wheel assembly 211 as an example, the first omnidirectional wheel assembly 211 includes a plurality of omnidirectional wheels 214 stacked in parallel on the output shaft of the stepping motor. The plurality of omnidirectional wheels 214 are preferably fixedly connected to each other, and each omnidirectional wheel 214 has the same diameter to achieve synchronous rolling along a direction perpendicular to the wheel axis under the drive of the stepping motor. At the same time, a plurality of rolling members 215 are freely sleeved on each omnidirectional wheel 214 along the circumferential direction ( Figure 4 ), and the rolling members 215 are generally spindle-shaped and can roll along the direction of the wheel axis.

[0037] Specifically, Figure 4 in (a) is a three-dimensional structure diagram of the omnidirectional wheel 214, and (b) is a front view of the omnidirectional wheel 214 showing the notch 217. As Figure 4 shown, the omnidirectional wheel 214 includes a circular omnidirectional wheel body 216 and a plurality of rolling members 215. The omnidirectional wheel body 216 can be formed by stacking multiple sheets and fastening them with screws. A plurality of notches 217 are provided on the sheets, and an elongated rolling shaft (whose curvature is substantially the same as the curvature of the sheet) is provided in each notch 217. The rolling members 215 are freely sleeved on the rolling shaft and accommodated in the notch area, so that the plurality of rolling members 215 are independent of each other and do not interfere with each other. Under the structure of the above omnidirectional wheel assembly, the stepping motor can control the omnidirectional wheel to roll along a direction perpendicular to the wheel axis, and the rolling in the form of the rolling members along the direction of the wheel axis is free and not controlled by the stepping motor.

[0038] Figure 5This is a schematic diagram of the principle of driving the body 100 to move omnidirectionally by the three-axis omnidirectional moving frame 200 of the present application. As shown in the figure, for the convenience of kinematic analysis, the ideal situation is taken as the basis. In the xy two-dimensional coordinate plane, point O is the center of the body chassis. The three wheels are distributed around point O at an angle of θ = 120°. Va, Vb, and Vc are the speed magnitudes of the three omnidirectional wheel assemblies. The arrow direction is the positive direction of the wheel movement. φ is the angle between the wheel surface and the x-axis, φ = π / 3. ω is the angular velocity of the body rotation. R is the distance from the center of the omnidirectional wheel assembly to the center of the body 100. When this mobile laser engraving machine is working, the movement of the body requires the cooperation of the three wheels. Through kinematic analysis based on the wheel speed and self-rotation angular velocity, the following formula (1) is obtained:

[0039]

[0040] The control system of the engraving machine realizes the movement of the omnidirectional wheel assembly by parsing the Gcode engraving instructions and programming according to the formula. For the drive of the omnidirectional wheel assembly, a stepper motor is selected because the controllable angular displacement of the stepper motor cannot be achieved by a DC motor. The stepper motor can calculate the displacement of a single omnidirectional wheel assembly using the number of pulses and the wheel diameter. After motion synthesis, the movement speed and direction of the entire laser engraving machine body can be obtained, and the engraving process can be completed in combination with the Gcode engraving instructions.

[0041] Specifically, the input engraving pattern is converted into Gcode engraving instructions (the instructions contain Vx and Vy expected by the engraving machine for each engraving position). After receiving the instructions, Vx and Vy are input into the above formula to obtain Va of the first omnidirectional wheel assembly 211, Vb of the second omnidirectional wheel assembly 212, and Vc of the third omnidirectional wheel assembly 213. According to the obtained results, they are respectively converted into corresponding pulse numbers to control the output of each stepper motor, so as to actuated each omnidirectional wheel assembly. The result of the movement cooperation of the three omnidirectional wheel assemblies is the actual movement speed and direction of the expected platform (i.e., the expected synthesis amount of Vx and Vy).

[0042] Here, the laser engraving tool head can engrave patterns on the engraving board by emitting laser light, and this engraving machine can realize the operation of multi-functionally replacing the engraving tool head, and can complete the engraving, cutting, and drawing processes of large-format.

[0043] In another embodiment of the present invention, since this laser engraving machine has a structure that can move omnidirectionally, in order to more intuitively feel the engraving process, a new type of positioning sensor - a wire-pulling type positioning sensor - can be provided to perform real-time positioning on this mobile laser engraving machine. As Figure 6Figure (a) in [reference] shows a schematic structural diagram of the cable-pulling type positioning sensor 300 provided by the present invention. The cable-pulling type positioning sensor 300 includes a grating encoder 310, a cable 320, and a cable box 330 for storing the cable 320. Among them, as Figure 6 shown jointly in Figures (a) and (b) in [reference], the grating encoder 310 includes a synchronous pulley 311, a grating code disk 312, and a photoelectric pair tube 313. The cable 320 is wound around the synchronous pulley 311 so as to rotate under the drive of the cable; the grating code disk 312 is fixedly arranged on the top of the synchronous pulley 311 and can rotate with the rotation of the synchronous pulley 311. The photoelectric pair tube 313 includes a light emitting tube and a light receiving tube arranged oppositely, and they are oppositely arranged on both sides of the grating code disk 313. The rotation of the grating code disk 313 can periodically cut off the light transmission of the photoelectric pair tube 313.

[0044] When the grating encoder 310 operates, the rotation of the grating code disk 312 will cut off the light transmission of the photoelectric pair tube 313, and a pulse signal as shown in Figure 7 will be generated at the receiving end. The pulse phases of the A-phase waveform and the B-phase waveform differ by 90°. By detecting which phase waveform pulse is received first, the rotation direction of the code disk can be judged. At the same time, by pulling the synchronous pulley to drive the code disk to rotate, the encoder outputs pulses. By calculation, the arc length of the synchronous pulley 311 rotating under one pulse can be obtained, which is approximately equal to the cable stretching length. Then, the number of pulses is counted, and according to the arc length of one pulse, the arc length after multiple pulses is calculated to obtain the cable stretching length, and the distance from the sensor to the engraving machine body is measured by this method.

[0045] Before the laser engraving machine performs engraving, two cable-pulling type positioning sensors 300 as described above can be arranged at the two side edge positions of the engraving plate ( Figure 8 S1 and S2 in [reference] respectively). Among them, the two grating encoders 310 are respectively fixedly connected to the machine body 100 through their respective cables. Using the above principle, each positioning sensor 30 can judge the distance from itself to the machine body 100, and then send the distance information to the host computer software respectively. Triangulation is used to process the data for engraving trajectory drawing, which can intuitively reflect the engraving process, as shown in Figure 8 [reference].

[0046] Generally speaking, as shown in Figure 9As shown in the figure, the engraving process of the mobile laser engraving machine provided by the present invention is carried out through the following steps: S1, input the engraving pattern in the host computer; S2, use a self-made plug-in to process and generate Gcode engraving instructions; S3, the host computer software transmits the generated Gcode instructions to the control system of the engraving machine; S4, the control system parses the Gcode instructions and controls the movement of each omnidirectional wheel assembly and the engraving process of the machine body; S5, during the engraving process, the wire-pulling sensor performs real-time positioning on the engraving machine and draws a trajectory map.

[0047] On the one hand, for the mobile laser engraving machine provided by this application, by setting a three-axis omnidirectional moving frame at the bottom of the engraving machine body, it can control the independent movement of three omnidirectional wheel assemblies according to the received engraving instructions, so as to realize the omnidirectional movement of the machine body, increase the engraving area, and the body is small and portable, enabling engraving anytime and anywhere. On the other hand, a new type of wire-pulling positioning sensor is designed. Instead of using a communication device for positioning, it uses a wire to achieve the ranging effect, and uses self-made software combined with triangulation technology to draw the engraving trajectory for observing the engraving effect.

[0048] In the description of the present invention, it should be understood that the orientation or positional relationship indicated by the terms "upper", "lower", "bottom", "top", "front", "rear", "inner", "outer", "left", "right", etc. is based on the orientation or positional relationship shown in the drawings, and is only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of the present invention.

[0049] Although the present invention has been described herein with reference to specific embodiments, it should be understood that these embodiments are merely examples of the principles and applications of the present invention. Therefore, it should be understood that many modifications can be made to the exemplary embodiments, and other arrangements can be designed, as long as they do not deviate from the spirit and scope of the present invention defined by the appended claims. It should be understood that different dependent claims and the features described herein can be combined in a manner different from that described in the original claims. It should also be understood that the features described in connection with a single embodiment can be used in other described embodiments.

Claims

1. A mobile laser engraving machine, characterized in that, it includes a machine body and a three-axis omnidirectional moving frame arranged at the bottom of the machine body. The three-axis omnidirectional moving frame includes three omnidirectional wheel assemblies evenly distributed along the circumferential direction of the machine body. The omnidirectional wheel assemblies are configured to be able to roll along the wheel axis direction and perpendicular to the wheel axis direction. The three omnidirectional wheel assemblies are independent of each other and can cooperate with each other to achieve the omnidirectional movement of the machine body; the machine body is movably arranged on an engraving plate, and a laser engraving cutter head for engraving the engraving plate is arranged at the bottom of the machine body; wire-pulling type positioning sensors are respectively arranged on both side edges of the engraving plate. The wire-pulling type positioning sensors include grating encoders. The two grating encoders are respectively connected to the machine body through the wires to form a triangular layout with the machine body. The positioning of the machine body is achieved by calculating the wire distances from the machine body to the two grating encoders; the wire-pulling type positioning sensors are electrically connected to a host computer, and the host computer is used for drawing an engraving trajectory according to the wire distance data; the three-axis omnidirectional moving frame further includes a stepping motor corresponding to each omnidirectional wheel assembly.

2. The mobile laser engraving machine according to claim 1, characterized in that, the omnidirectional wheel assembly includes a plurality of omnidirectional wheels stacked in parallel. The omnidirectional wheel includes an omnidirectional wheel body and a plurality of rolling elements that are independent of each other and freely sleeved on the omnidirectional wheel body along the circumferential direction.

3. The mobile laser engraving machine according to claim 1 or 2, characterized in that, the included angle between the wheel surfaces of two adjacent omnidirectional wheel assemblies is 60°.

4. The mobile laser engraving machine according to claim 3, characterized in that, the rolling linear velocity of each omnidirectional wheel assembly along the direction perpendicular to the wheel axis is determined by the following formula: where Va, Vb, and Vc are respectively the rolling linear velocities of the three omnidirectional wheel assemblies along the direction perpendicular to the wheel axis, ψ is the included angle between the wheel surfaces, ω is the spin angular velocity of the machine body, R is the distance from the center of the omnidirectional wheel assembly to the center of the machine body chassis, and Vx and Vy are respectively the moving linear velocities of the machine body in the x-axis direction and the y-axis direction.

5. The mobile laser engraving machine according to claim 1 or 2, characterized in that, a control system is further arranged inside the machine body, which is used for receiving an engraving instruction sent by the host computer and controlling the movement of the three omnidirectional wheel assemblies and the engraving action of the machine body according to the engraving instruction.

6. The mobile laser engraving machine according to claim 1, characterized in that, the grating encoder includes: a synchronous pulley, around which the wire is wound so that it rotates under the drive of the wire; a grating code disk, which is fixedly arranged on the top of the synchronous pulley and can rotate with the rotation of the synchronous pulley; and photoelectric pairs of tubes, which are relatively arranged on both sides of the grating code disk, and the rotation of the grating code disk can periodically cut off the light transmission of the photoelectric pairs of tubes.

7. The mobile laser engraving machine according to claim 6, characterized in that, The cable-pulling type positioning sensor further includes a cable box for storing the cable.

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