| This paper investigates the possibility of on-line measurement of laser and fuzzy control of wood milling processing according to fuzzy control theory. This study is advanced with the first time in international. The control system are consisted of computer, laser sensor, A/D converter and the power driver of output etc. The surface roughness Rz is used as quality index. Douglas fir of coniferous tree and Beech of broadleaf tree is selected as the experiment materials. This study work is done on CNC miller (planner processing) for wood processing. Firstly, Douglas fir, Hinoki, Beech and Padauk are selected as experiment specimen, this four specimens have different color, grain and density. In order to get at reflect effect of laser measurement signal to wood surface characteristic with different materials, the linearity calibration experiment of laser sensor are carried out and are acquired various material calibration factor (ratio factor); Secondly, laser sensor quantitative measure wood surface roughness method and wood surface defect recognition are studied by the test system consisting of FFT analyzer, laser sensor etc. At first the laser sensor and stylus instrument are used to respectively measure same part of same specimen, under the same measure condition, the ratio relation of the measurement datum of laser sensor and stylus instrument for 1/0.9 is acquired. Then using the measurement data of stylus instrument are calibrated the measurement data of laser sensor, to make both measurement data are identical, the experiment of wood surface defect identify shows that this system has the feature of fast and accurate to measure wood surface crack and knob. After that, using the surface roughness on-line measurement system that consists of computer, laser sensor, A/D converter and so on. A study of on-line measurement of the surface roughness in the milling processing was done. And same result with stylus instrument non-on-line measurement was obtained. At last, the experiment research on the fuzzy on-line control for wood milling processing is done. The fuzzy on-line control system of close-loop is made up when the power driver board is added in primary on-line checking system. Taking the surface roughness measurement signal from laser sensor is used as the input signal of fuzzy control. Using the fuzzy reasoning calculate, making the fuzzy conclusion, giving the drive signal, the feed speed of CNC work table is adjusted momentarily. Under this way the change of surface roughness can be controlled, and the processing quality can also be improved. The consequence of this experiment have justified that the surface roughness of adopting fuzzy on-line control have decreased on the average by 15% to 20% compared with general milling processing process.
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