| The control system is an integral part of all components of a laser.With the widespread use of lasers,the demands placed on control systems are increasing.From the early mechanical control methods to diversified control,intelligentialize must be the development direction of laser control systems.With its powerful functions,rich peripherals and stable development environment,STM32 series microcontrollers are widely used in various industries to advance the intelligent process.Its application in the field of optics has great significance for the reform of laser control methods.Therefore,the embedded STM32 series of micro control system was used to achieve intelligent control of the pulsed laser.The main part of the STM32 series control system design was divided into five parts:interactive interface design,drive circuit and interface design,component selection and laser design,auxiliary function design and system testing.The software part of the control system was designed by transplanting EMWIN system files based on the HAL library.The main content of the software part was the design of human-computer interaction interface.,which realized the visualization of the information interaction between the user and hardware.The interface was supported by the TFT-LCD liquid crystal screen with the touchpad.Based on the 180 MHz crystal oscillator and multi-channel pulse width modulation(PWM)signal of the control system,the control signals were designed to achieve precise control of the laser:the xenon lamp voltage was continuously adjustable from 0 to 750 V,and the width of the pulse was in the range of ?s,continuously adjustable in the range of 1000 ?s,and the pulse frequency was intermittently adjustable in the range of 200 Hz.The main work of the hardware part was the design of the drive circuit of control signal.Due to the small current of the TTL control signal generated by the system,it was not big enough to drive the hardware.Therefore,we have designed a corresponding driving circuit to amplify the signal,and then collect it at the output port to complete the effective input of the control signal to the hardware.The part of component's selection introduced the main core components used in the control system,and made reasonable choices through analysis and comparison.The pulsed high-power holmium laser was designed with a Cr:Tm:Ho:YAG laser crystal.The laser output was achieved by three concentrating cavity laser systems combined with a stepper motor and a 45° reflector,and the average output power exceeded 100 W.Due to the large output power of the laser,for operational safety,the auxiliary design mainly improved the safety monitoring capability of the control system.The system was equipped with a temperature sensor and an ultrasonic ranging module to monitor the temperature and safety distance of the laser in real time to improve the safety of the laser.The temperature monitoring accuracy isą0.5 ?,and the safety distance monitoring accuracy isą0.5 mm.Finally,this paper tested the control system and laser from various aspects,including the driving stability of xenon lamp voltage,the driving stability of pulse width,the output power of single laser system,the laser beam output power,etc.The results showed that this control system can stably drive the laser and other auxiliary modules,and all the indicators can meet the design requirements. |
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