Continuous smart light source controller design for laser structure light measurement

During the measurement procedure of laser structure light vision, the measurement object material surface difference and geometric curvity would both affect the laser light-spot image quality, and influence the precision accuracy of measurement data processing. For adapting to application various circumstances of industrial measurement, the current controlling of laser diode of structure light was adopted. A low cost miniwatt semiconductor laser controller design solution was submitted based on the analysis of laser diode performance. The PWM signal driving technique was researched in this paper, which applied ARM MCU to generating PWM output signals, and then signals were transformed into analog laser controlling signal by cascade circuits of the resistance-capacitance filter circuit with optoisolator, operational amplifier follower and voltage controlled constant current source (V-I) circuit. The ratio and reference frequency of PWM signal could be set by the modbus serial agreement between host machine and laser controller. A series of imaging experiments with laser structure light projection were be done, which indicated adjusting laser structure light output at the right level would be able to optimize the measurement result and improve the adaptability of laser vision system. The experimental results show that the system can run stably. Copyright ©2021 Infrared and Laser Engineering. All rights reserved.