激光熔覆制造中的粉末输送检测与控制技术

针对激光熔覆制造过程中存在的粉末输送不均匀问题,提出了一种基于光电传感器的粉末流量检测与控制方法.在分析粉末流对光线的吸收特性的基础上,设计了一种新型的光电式粉末流量传感器.该传感器采用红色发光二极管作为光源,二极管所发出的光线经粉末流散射后照射到光电变送器上.通过信号调理可以将传感器输出电压信号与粉末流量相对应.对该传感器进行测试,试验数据表明:粉末流量与传感器输出信号具有较好的线性相关度.为实现粉末流量控制,基于模糊PID控制策略,开发了一套采用PIC单片机作为控制元件的粉末流控制器,对辊轮式送粉器的粉末传榆进行流量控制,粉末流量稳定性提高60%以上.

Detecting and controlling technology for powder delivery in laser cladding manufacturing

The nonuniformity problem in powder delivery seriously affects the manufacturing quality in laser cladding.To solve this problem,a novel detecting and controlling method using optoelectronic sensor was introduced.Based on analyses of light absorption characteristics of powder flow,an optoelectronic sensor for powder flow detecting was designed.The sensor used a red diode as the light source,and a photodiode with amplifier as the receiver.When light from the diode passed through powder flow,energy received by photodiode would decrease because of absorption,diffusion,and reflection.The calibration of the sensor show that there is a linear relationship between the powder delivery rate and the sensor signal output.To control the powder delivery rate,a controller using PIC microprocessor was developed,and the fuzzy control strategy was applied to process the sampling signals.Utilizing the controller,powder delivery experiments were carried on a roller type powder feeder.The experimental results indicate that the powder delivery stability could be improved by 60%.