进行海上灯光诱鱼作业时,船体横摇改变了发光二极管(LED)集鱼灯的照明角度,导致海面光照不断变化,对吸引和聚集趋光性鱼类产生不利影响。提出了一种利用自由曲面透镜实现扇形光强分布的方法,在Y-Z和X-Y平面上的发散角分别为110°和10°。分析了LED集鱼灯在渔船横摇角度变化范围(-10°~10°)内的目标面相对照度分布的相似性和误差率。模拟结果和实验结果的正交归一化相似性(NCC)分别大于98.50%和99.53%,均方根误差(RMSE)分别小于5.56%和4.60%。与普通LED集鱼灯和金卤灯比较,本设计显著提高渔船横摇时LED集鱼灯的光照稳定性。结果表明,在不同照明角度下,LED集鱼灯的自由曲面透镜能很好地实现海面上的稳定光照。

During the operation of fishing with light at sea, rolling motion of the fishing boat changes the illumination angle of the light-emitting diode (LED) fishing lamp, resulting in continuous changes of the sea surface illumination, which has an adverse effect on attracting and gathering phototactic fish. This article proposes a method using a free-form surface lens to realize a fan-shaped light intensity distribution, with the divergence angles on the X-Y and Y-Z planes being 110° and 10°, respectively. The similarity and error rate of the relative illuminance distribution of the target plane within the illumination angle range of -10°--10° were analyzed. The normalized cross correlation (NCC) of the simulation results and the experimental results are greater than 98.50% and 99.53% respectively, and the root mean square error (RMSE) are less than 5.56% and 4.60%, correspondingly. By comparing this design with a standard LED fishing lamp and metal halide lamp, the results show that the proposed design significantly improves the illumination stability of the LED fishing lamps when the fishing boat rolls, indicating that the free-form surface lens is able to provide stable illumination on the sea surface at different illumination angles.