Equipment for monitoring laser cutting machine

Abstract

The utility model relates to the field of laser cutting, in particular to equipment for monitoring a laser cutting machine. The rotation angle and position information of the motor is collected through an encoder and converted into differential signals; the light emitting power of the laser cutting machine is collected through a photoelectric sensor and converted into an analog signal; receiving the differential signal through an encoder acquisition circuit, and generating a single-ended signal; a single-end signal is received through a level conversion circuit, level conversion is carried out, and the signal is transmitted to an SOC main control module; the analog signal acquisition module is used for receiving an analog signal, generating a digital signal and transmitting the digital signal to the SOC main control module; the SOC master control module receives the single-end signal and the digital signal, processes the single-end signal and the digital signal and finally transmits the single-end signal and the digital signal to the upper computer, the running track and the light-emitting power of the motor are displayed on a displayer of the upper computer in real time, operation, searching and analysis of problems are facilitated, and a user judges and solves the problems by searching and watching the running track and the light-emitting power of the motor at a certain moment.

Description

TECHNICAL FIELD

[0001] The utility model relates to laser cutting technical field especially a device for monitoring laser cutting machine. BACKGROUND

[0002] As a new processing equipment, laser cutting machine is gradually welcomed by the majority of users because of its high efficiency, precision, flexibility and other characteristics. Laser cutting technology continues to innovate, making the performance of laser cutting machine reach a new height. At present, laser cutting machine has realized multi-axis control, automatic tracking, quick switching and other technical innovations, which provides guarantee for more extensive application. Although the laser cutting machine industry has good prospects, it still faces some challenges, such as the increasing requirements of some users on laser cutting machine, higher requirements on processing precision, speed and other aspects. The workpiece to be cut becomes smaller and smaller, and the requirement on precision is also higher and higher. Laser cutting system manufacturers face the increasing demand of users, and realize the efficient and high-precision cutting of equipment, which is an urgent problem.

[0003] The existing laser cutting system is usually built-in a pulse counter for collecting the pulse number of the encoder. The rotating position of the motor is output to the pulse counter through the encoder pulse to form a system, which can only count the position of the motor, and cannot identify the fault problem point during laser cutting. When the problem occurs, which part of the power is too large or the position is not corresponding, it is impossible to form a closed loop system of power and position.

[0004] Therefore, an urgent need exists for a device for monitoring laser cutting machine, which is used for real-time collection of the light emitting power of the laser cutting machine and the motion trajectory of the motor, and can quickly find abnormal problems such as large cutting light emitting power or inaccurate cutting position. Utility model content

[0005] To solve the problem that the existing laser cutting machine cannot collect and monitor the light emitting power and the running trajectory of the motor in real time.

[0006] The utility model provides a kind of equipment for monitoring laser cutting machine, including motor, encoder and photoelectric sensor installed on laser cutting machine and shell and circuit module located in shell inside;Motor is used to drive laser cutting machine;Encoder and the rotating shaft of motor are connected, and encoder is used to convert the rotation angle and position information of motor into differential signal;Photoelectric sensor is used to convert the luminous power of laser cutting machine into analog signal;Its characterized in that: circuit module includes encoder acquisition circuit, level conversion circuit, analog signal acquisition module, digital trigger pulse circuit, SOC main module and host computer;Encoder acquisition circuit and encoder are electrically connected, and encoder acquisition circuit is used to acquire differential signal from encoder and generate single-ended signal;Level conversion circuit is electrically connected with encoder acquisition circuit and SOC main module respectively, and level conversion circuit is used to receive single-ended signal from encoder acquisition circuit, and after level conversion, SOC main module is input;Analog signal acquisition module is electrically connected with photoelectric sensor by SMA input interface and coaxial cable, and analog signal acquisition module is used to acquire analog signal from photoelectric sensor and generate digital signal;Digital trigger pulse circuit and SOC main module are electrically connected, and digital trigger pulse circuit is used to trigger analog signal acquisition and encoder differential signal acquisition;SOC main module is electrically connected with level conversion circuit and analog signal acquisition module respectively, and SOC main module is connected with host computer by RJ45 network interface, and SOC main module is used to receive single-ended signal from level conversion circuit and digital signal from analog signal acquisition module, and after processing, it is transmitted to host computer, and host computer includes display.

[0007] Preferably, the encoder acquisition circuit includes an RS-485 differential chip, and the RS-485 differential chip has four groups of independent differential input interfaces.

[0008] Preferably, the level conversion circuit includes a bidirectional level conversion chip, and the bidirectional level conversion chip is used for signal conversion between communication interfaces of different levels.

[0009] Preferably, the analog signal acquisition module includes a gain adjustment circuit and a digital-to-analog converter, the gain adjustment circuit is used for adjusting the amplitude of the analog signal, and the digital-to-analog converter is used for converting the analog signal into a digital signal.

[0010] Preferably, the analog signal acquisition module further includes an input buffer and a differential driver, and the input buffer and the differential driver are located between the gain adjustment circuit and the digital-to-analog converter; the input buffer is used for isolating the input analog signal and the subsequent circuit, and provides high input impedance and low output impedance; and the differential driver is used for converting the analog signal into a differential signal or enhancing the driving capability of the existing differential signal.

[0011] Preferably, the SOC master module comprises an SOC chip, a direct current converter, a clock source and a gigabit Ethernet physical layer interface, the SOC chip integrates an FPGA logic array, the direct current converter is used for converting a power supply voltage into various voltage levels suitable for the SOC master module, the clock source is used for providing a clock signal, and the gigabit Ethernet physical layer interface is used for interactive communication with an upper computer through an RJ45 network port.

[0012] Preferably, the SOC master module further comprises a 120-pin connector, a USB hub and a memory, the 120-pin connector is used for physical connection with peripheral devices, the USB hub is used for data transmission, and the memory is used for saving program codes and other non-volatile data.

[0013] Preferably, the digital trigger pulse circuit is provided with two paths, the digital trigger pulse circuit comprises a high-speed optocoupler, the digital trigger pulse circuit is electrically connected with the SOC master module, the digital trigger pulse circuit is used for receiving an input signal of the laser cutting machine and autonomously selecting a rising edge or a falling edge according to requirements of the laser cutting machine, and the selected rising edge or falling edge is used as a control trigger point for starting the SOC master module to count the motor position or the light emitting power.

[0014] Preferably, the circuit module further comprises a protection circuit, the protection circuit comprises a positive voltage hot plug controller chip and a MOSFET device for a switching power supply, and the protection circuit is used for intelligently detecting overvoltage, undervoltage and overcurrent states and performing power-off and self-recovery.

[0015] Preferably, the upper computer is a computer system.

[0016] The encoder is used for collecting the rotation angle and position information of the motor and converting the information into a differential signal; the photoelectric sensor is used for collecting the light emitting power of the laser cutting machine and converting the light emitting power into an analog signal; the encoder collecting circuit is used for receiving the differential signal and generating a single-ended signal; the level conversion circuit is used for receiving the single-ended signal and performing level conversion and transmitting the single-ended signal to the SOC master module; the analog signal collecting module is used for receiving the analog signal and generating a digital signal and transmitting the digital signal to the SOC master module; and the SOC master module is used for receiving the single-ended signal and the digital signal and performing processing, and finally transmitting the single-ended signal and the digital signal to the upper computer, so that the running track of the motor and the light emitting power are displayed in real time on a display of the upper computer, and it is convenient to find and analyze problems, and the user can determine and solve problems by finding and watching the running track of the motor and the light emitting power at a certain moment. BRIEF DESCRIPTION OF DRAWINGS

[0017] Fig. 1 It is a front view of the device for monitoring the laser cutting machine.

[0018] Fig. 2 It is a rear view of the device for monitoring the laser cutting machine.

[0019] In the figure: 1 - housing; 2 - encoder acquisition circuit. DETAILED DESCRIPTION

[0020] The technical solutions in the embodiments of the present application will be clearly and completely described below with reference to the drawings in the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, rather than all the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without creative work fall within the scope of protection of the present application.

[0021] Reference Figs. 1-2 A device for monitoring a laser cutting machine, comprising a motor, an encoder and a photoelectric sensor mounted on the laser cutting machine, a housing 1 and a circuit module located inside the housing 1; the motor is used to drive the laser cutting machine; the encoder is connected with the rotating shaft of the motor, and is used to convert the rotation angle and position information of the motor into a differential signal; the photoelectric sensor is used to convert the light emitting power of the laser cutting machine into an analog signal; characterized in that: the circuit module comprises an encoder acquisition circuit 2, a level conversion circuit, an analog signal acquisition module, a digital trigger pulse circuit, a SOC master control module and an upper computer; the encoder acquisition circuit 2 is electrically connected with the encoder, and is used to acquire the differential signal from the encoder and generate a single-ended signal; the level conversion circuit is electrically connected with the encoder acquisition circuit 2 and the SOC master control module respectively, and is used to receive the single-ended signal from the encoder acquisition circuit 2, and input the single-ended signal into the SOC master control module after level conversion; the analog signal acquisition module is electrically connected with the photoelectric sensor through an SMA input interface and a coaxial cable, and is used to acquire the analog signal from the photoelectric sensor and generate a digital signal; the digital trigger pulse circuit is electrically connected with the SOC master control module, and is used to trigger the acquisition of the analog signal and the differential signal of the encoder; the SOC master control module is electrically connected with the level conversion circuit and the analog signal acquisition module respectively, and is connected with the upper computer through an RJ45 network port; the SOC master control module is used to receive the single-ended signal from the level conversion circuit and the digital signal from the analog signal acquisition module, and transmit the signals to the upper computer after processing, and the upper computer comprises a display.

[0022] The rotation angle and position information of the motor are collected by the encoder and converted into a differential signal; the light-emitting power of the laser cutting machine is collected by the photoelectric sensor and converted into an analog signal; the differential signal is received by the encoder collection circuit 2 and a single-ended signal is generated; the single-ended signal is received by the level conversion circuit and is subjected to level conversion and transmitted to the SOC master module; the analog signal is received by the analog signal collection module and a digital signal is generated and transmitted to the SOC master module; the SOC master module receives the single-ended signal and the digital signal and processes them, and finally transmits them to the upper computer, so that the running track of the motor and the light-emitting power can be displayed in real time on the display of the upper computer, facilitating operation and analysis of problems, and users can determine the solution by looking at the running track of the motor and the light-emitting power at a certain moment.

[0023] The laser cutting device has an encoder inside, and the running position and track of the motor are transmitted in real time by the encoder to form a closed-loop control feedback system, and the actual running position and track can be obtained by connecting the encoder of the laser cutting device and converting and analyzing it; the light-emitting power of the laser cutting device is mainly converted into an analog signal by the photoelectric sensor, and the frequency and amplitude of the analog signal are collected, processed and uploaded to the upper computer for conversion, so that the light-emitting power can be obtained; since the collection of the analog signal and the collection of the encoder position information are controlled by a digital trigger pulse circuit, the internal record of the device of the laser cutting machine is monitored with a time stamp, so that the motor position and the light-emitting power can be accurately matched, so that once a problem occurs in the laser cutting device, the problem point can be easily found and corresponding solutions can be made.

[0024] In some embodiments, the encoder collection circuit 2 includes an RS-485 differential chip, which has four independent differential input interfaces.

[0025] The encoder collection circuit 2 is used for X-axis and Y-axis 2-way collection input interface, wherein each encoder interface has A, B, Z three phases corresponding to different signals respectively, the encoder collection circuit 2 uses an RS-485 differential chip, which supports a maximum rate of 50MHz and has four independent differential input interfaces, can convert the differential signal input of X, Y axis A, B, Z into single-ended signal output, and do level conversion processing to 3.3V input for SOC master module for counting and algorithm processing.

[0026] In some embodiments, the level conversion circuit includes a bidirectional level conversion chip, which is used for signal conversion between different level communication interfaces.

[0027] Specifically, the bidirectional level conversion chip is model SN74LVC4245APWR, which provides stable level conversion and ensures the integrity and reliability of the signal.

[0028] In some embodiments, the analog signal acquisition module comprises a gain adjustment circuit and a digital-to-analog converter, the gain adjustment circuit is used to adjust the amplitude of the analog signal, and the digital-to-analog converter is used to convert the analog signal into a digital signal.

[0029] The gain adjustment circuit comprises an amplifier, specifically, the model of the amplifier is OPA659, and the gain adjustment circuit can select one or ten times gain.

[0030] Preferably, the analog signal acquisition module further comprises an input buffer and a differential driver, the input buffer and the differential driver are located between the gain adjustment circuit and the digital-to-analog converter; the input buffer is used to isolate the input analog signal and the subsequent circuit, and provide high input impedance and low output impedance; the differential driver is used to convert the analog signal into a differential signal, or enhance the driving ability of the existing differential signal.

[0031] The analog signal acquisition module in combination with the SOC master module can be used to collect analog signals within 20M, the analog signal input interface is SMA, the measured analog signal is generated when the laser cutting equipment emits and cuts the product, and after being converted into an analog signal by a photoelectric sensor, the analog signal is transmitted to the analog signal acquisition module through the SMA input interface and a coaxial cable to collect and analyze parameters such as voltage and frequency. The analog signal acquisition module supports ±10V and analog signal input within 20MHz; the analog signal acquisition module comprises an AC coupling capacitor and a DC coupling resistor, and supports AC and DC coupling modes; the analog signal acquisition module internally has a probe attenuation adjustment circuit, which can select one or ten times gain, and can replace a small oscilloscope to measure signals and noise.

[0032] In some embodiments, the SOC master module comprises a SOC chip, a DC converter, a clock source and a gigabit Ethernet physical layer interface, the SOC chip integrates an FPGA logic array, the DC converter is used to convert the power supply voltage into various voltage levels suitable for the SOC master module, the clock source is used to provide a clock signal, and the gigabit Ethernet physical layer interface communicates with the upper computer through an RJ45 network port.

[0033] Specifically, the SOC chip is a high-end system chip in the Xilinx ZNYQ7000 series, the SOC chip internally has rich logic resources, supports various digital interfaces, and rich IO resources can compile I2C, SPI, parallel bus trigger calculation and other operation processing functions.

[0034] Preferably, the SOC master module further comprises a 120-pin connector, a USB hub and a memory, the 120-pin connector is used for physical connection with peripheral devices, the USB hub is used for data transmission, and the memory is used for saving program codes and other non-volatile data.

[0035] 120The needle connector and the USB hub provide a rich interface, support multiple peripherals and data transmission, make the system have higher expansibility and flexibility; the memory is used to save program code and non-volatile data, ensure the stable operation of the system and the safety of data, support fault recovery and system maintenance.

[0036] In some embodiments, the digital trigger pulse circuit is provided with 2 paths, the digital trigger pulse circuit contains a high-speed optocoupler, the digital trigger pulse circuit is electrically connected with the SOC master module, the digital trigger pulse circuit is used for receiving the input signal of the laser cutting machine, and the rising edge or the falling edge is autonomously selected according to the requirements of the laser cutting machine, and the selected rising edge or falling edge is used as a control trigger SOC master module to start the time point of counting motor position or light emitting power.

[0037] The high-speed optocoupler is used to realize the level conversion between the input signal of the laser cutting device and the detection device, and at the same time provides electrical isolation, ensures the accurate transmission of the signal and protects the circuit from interference. The input signal of the laser cutting device refers to the signal emitted from the laser cutting device for triggering the device for monitoring the laser cutting machine to start working. The input signal of the laser cutting device usually includes a PWM pulse signal, and the input signal of the laser cutting device is used to indicate the enable state of the laser. The input signal of the laser cutting device determines the starting time of data acquisition, ensures that the collected data corresponds to the actual working state of the laser, saves resources and space, and is flexible to control. The digital trigger pulse circuit supports external input 5V or 24V PWM pulse signal, and the maximum pulse rate is 10MHz.

[0038] In some embodiments, the circuit module further comprises a protection circuit, the protection circuit comprises a positive voltage hot plug controller chip and a MOSFET device for switching power supply, and the protection circuit is used for intelligently detecting overvoltage, undervoltage and overcurrent state, and performing power-off and self-recovery.

[0039] The protection circuit can effectively prevent the circuit module or the measured laser cutting machine from short circuiting and catching fire. Specifically, the protection circuit limits the minimum voltage to 23V, the maximum voltage to 27.5V, and the minimum current to 2.75A.

[0040] In some embodiments, the host computer is a computer system.

[0041] Full use is made of the powerful computing power, rich software resources and convenient man-machine interaction function of the computer system, and the performance, reliability and user experience of the whole system are improved.

[0042] Specific working mode:

[0043] Specific, the encoder is an optical incremental encoder, the encoder is used for 2-way encoder acquisition circuit 2, wherein the X axis and the Y axis have three phases A, B and Z respectively, the differential signal output by the encoder is converted into a single-ended signal by the encoder acquisition circuit 2, and then an algorithm is processed, the number of pulses of the encoder and the timestamp are calculated.

[0044] When the host computer issues a start monitoring command, the FPGA starts sampling the A / B pulse signals of the X axis and the Y axis to count the number of forward and reverse rotations through a clock source with a frequency of 125MHz, and the algorithm is that when the edge of the A pulse signal leads the edge of the B pulse signal by 90 degrees, it is forward rotation, and the counter is incremented by 1, otherwise, the edge of the B pulse signal leads the edge of the A pulse signal by 90 degrees, it is reverse rotation, and the counter is decremented by 1. The host computer also starts recording time, ADC data acquisition, sampling X axis and Y axis A / B / Z pulse signal waveform, and laser PWM waveform when sending the detection command. When the laser is enabled, a pulse signal is given to the FPGA as a trigger signal, and when the trigger signal is valid, the frame header information (64h'ffff_ffff_ffff_ffff), the current recorded time, the forward and reverse rotation counters of the X axis and the Y axis, and the ADC collected voltage data are sequentially uploaded to one of the DDR memory intervals in the cache through the DMA mode, and then uploaded to the host computer through the network port. When the trigger signal is valid, the frame header information (32'hAAAA_AAAA), the collected X axis and Y axis A / B / Z pulse signal waveform data are sequentially uploaded to another DDR memory interval in the cache through the DMA mode, and then uploaded to the host computer through the RJ45 network port. After the host computer receives the data, the frame length information at the moment when the laser is enabled, the timestamp of each frame data, the forward and reverse rotation count values of the X axis and the Y axis, the X axis and Y axis A / B / Z pulse signal waveform data, the laser PWM waveform data and the ADC collected laser voltage data can be obtained by cutting according to the frame header information. Thus, the host computer can draw the motor running track and the laser light power according to the information.

[0045] The beneficial effects of the utility model are reflected in:

[0046] 1) Currently there is no instrument on the market that can real-time collect and monitor the light power and motor running track of laser cutting equipment, the device for monitoring the laser cutting machine can output 5V or 24V level PWM pulse signal according to the laser cutting machine, support maximum frequency 10MHz, can set the effective way of PWM pulse signal trigger detection according to the demand of laser cutting equipment through RJ45 network port, such as rising edge trigger or falling edge trigger, can continuously collect analog signals within ±10V at a high sampling rate of 40M, display the motor running position track and light power of the cutting equipment on the computer interface in real time, facilitate operation to find and analyze problems, users can find and watch the power and position at a certain moment to judge and solve the problem.

[0047] 2) The device for monitoring the laser cutting machine has high precision, fast response, small size, can be installed in the laser cutting machine, low price, supports large data volume data transmission, has self-circuit and algorithm to support X, Y axis encoder position detection, supports analog signal collection and real-time correspondence with motor position. Only a separate motor encoder statistics instrument on the conventional market, the instrument processes with soft algorithm through the MCU of STM32, which is different from the device, and cannot collect analog signals, so it cannot analyze and solve abnormal problems.

[0048] Although the embodiments of the utility model have been shown and described, it can be understood by those skilled in the art that various changes, modifications, replacements and variations can be made to these embodiments without departing from the principles and spirits of the utility model, the scope of the utility model is defined by the appended claims and their equivalents.

Claims

1. A device for monitoring a laser cutting machine, comprising a motor, an encoder and a photoelectric sensor mounted on the laser cutting machine, and a housing and a circuit module located inside the housing; the motor is used to drive the laser cutting machine; the encoder is connected with the rotating shaft of the motor, and is used to convert the rotation angle and position information of the motor into a differential signal; the photoelectric sensor is used to convert the light emitting power of the laser cutting machine into an analog signal; characterized in that: The circuit module comprises an encoder acquisition circuit, a level conversion circuit, an analog signal acquisition module, a digital trigger pulse circuit, an SOC master module and an upper computer; The encoder acquisition circuit is electrically connected with the encoder and is used for acquiring differential signals from the encoder and generating single-ended signals; The level conversion circuit is electrically connected with the encoder acquisition circuit and the SOC master module respectively, is used for receiving the single-ended signals from the encoder acquisition circuit, and inputs the single-ended signals into the SOC master module after level conversion; The analog signal acquisition module is electrically connected with the optical sensor through an SMA input interface and a coaxial cable, is used for acquiring analog signals from the optical sensor, and generates digital signals; The digital trigger pulse circuit is electrically connected with the SOC master module, is used for triggering the acquisition of the analog signals and the differential signals of the encoder; The SOC master module is electrically connected with the level conversion circuit and the analog signal acquisition module respectively, is connected with the upper computer through an RJ45 network port, is used for receiving the single-ended signals from the level conversion circuit and the digital signals from the analog signal acquisition module, and transmits the signals to the upper computer after processing, and the upper computer comprises a display.

2. An apparatus for monitoring a laser cutting machine as claimed in claim 1, wherein: The encoder acquisition circuit comprises an RS-485 differential chip, and the RS-485 differential chip has four groups of independent differential input interfaces.

3. An apparatus for monitoring a laser cutting machine as claimed in claim 2, wherein: The level conversion circuit comprises a bidirectional level conversion chip, and the bidirectional level conversion chip is used for signal conversion between communication interfaces with different levels.

4. An apparatus for monitoring a laser cutting machine as claimed in claim 3, wherein: The analog signal acquisition module comprises a gain adjustment circuit and a digital-to-analog converter, the gain adjustment circuit is used for adjusting the amplitude of the analog signals, and the digital-to-analog converter is used for converting the analog signals into digital signals.

5. An apparatus for monitoring a laser cutting machine as claimed in claim 4, wherein: The analog signal acquisition module further comprises an input buffer and a differential driver, and the input buffer and the differential driver are located between the gain adjustment circuit and the digital-to-analog converter; the input buffer is used for isolating the input analog signals and subsequent circuits, and provides high input impedance and low output impedance; The differential driver is used for converting the analog signals into differential signals or enhancing the driving capability of the existing differential signals.

6. An apparatus for monitoring a laser cutting machine as defined in claim 4, wherein: The SOC master module comprises an SOC chip, a direct current converter, a clock source and a gigabit Ethernet physical layer interface, the SOC chip integrates an FPGA logic array, the direct current converter is used for converting a power supply voltage into a voltage level suitable for the SOC master module, the clock source is used for providing a clock signal, and the gigabit Ethernet physical layer interface is used for interactive communication with the upper computer through an RJ45 network port.

7. An apparatus for monitoring a laser cutting machine as defined in claim 6, wherein: The SOC master module further comprises a 120-pin connector, a USB hub and a memory, the 120-pin connector is used for physical connection with peripheral equipment, the USB hub is used for data transmission, and the memory is used for saving program codes and non-volatile data.

8. An apparatus for monitoring a laser cutting machine as defined in claim 1, wherein: The digital trigger pulse circuit has two paths, contains a high-speed optocoupler, is electrically connected with the SOC master module, is used for receiving input signals of a laser cutting machine, and autonomously selects a rising edge or a falling edge according to the requirements of the laser cutting machine, and the selected rising edge or falling edge is used as a control trigger point for starting the SOC master module to count the motor position or the light emitting power.

9. An apparatus for monitoring a laser cutting machine as defined in claim 1, wherein: The circuit module further comprises a protection circuit, which comprises a positive voltage hot plug controller chip and a MOSFET device for a switching power supply, and is used for intelligently detecting overvoltage, undervoltage and overcurrent states and carrying out power-off and self-recovery.

10. An apparatus for monitoring a laser cutting machine as defined in claim 1, wherein: The upper computer is a computer system.

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