Search

Light is the main energy source for plants to carry out photosynthesis, and the quality of light directly affects the yield and quality of crops. In view of the fact that most of the existing plant light supplement systems are based on the photosynthetic capacity of functional leaves, problems such as photoinhibition of new leaves in the canopy and lack of supplementary light in the functional leaf position between plants, and the position of light supplement can’t be adjusted dynamically to adapt to crop growth exist, taking facility cucumber as the research object, an stereo light environment intelligent control system based on the characteristic differences of plant light requirements was designed in this research. The system is composed of intelligent control subsystem, canopy-plant environment monitoring subsystem, canopy-plant LED light-compensating lamp subsystem, and light-compensating lamp lifting subsystem. Wireless communication between subsystems was realized by using ZigBee technology. The canopy-interplant environmental monitoring subsystem obtains the canopy and interplant environmental information respectively and sends them to the intelligent control subsystem. According to the real-time environmental information, the intelligent control subsystem invokes the canopy regulation model and the appropriate interplant leaf position regulation model to obtain the corresponding regulation target values, and sends them to the canopy-interplant light-compensating lamp to realize the dynamic real-time regulation of the canopy and interplant light-compensating lamp. In November 2018, the stereoscopic light-compensating equipment and the traditional canopy light-compensating equipment were tested and verified with the natural control in the vegetable base of the vegetable industry comprehensive service area of Jingyang County, Shaanxi province. The results showed that, compared with the traditional canopy light-compensating area, the cucumber plant height and stem diameter in the stereoscopic light-compensating area increased significantly, and the average plant height and stem diameter increased by 8.03% and 7.24%, respectively. Compared with the natural treatment area, the average plant height and stem diameter increased by 26.51% and 36.03%, respectively. And during the one-month picking period, compared with the traditional canopy light-compensating area, the yield of the stereoscopic light-compensating area increased by 0.28 kg/m2, the economic benefit increased by 2.82 CNY/m2, the yield of the stereoscopic light-compensating area increased by 1.39 kg/m2, and the economic benefit increased by 4.88 CNY/m2; compared with the natural treatment area indicating that the stereoscopic light environment control system can improve economic benefits and has good application and promotion values.

Expression variation is one of the most important factors that considerably influence the performance of face recognition. In order to enhance robustness to expression variations, a procedure of 3D face recognition based on depth image and SURF Operator is proposed. We use Fisher Linear Discriminant (FLD) method on the depth image to perform coarse recognition first to catch the highly ranked 3D faces. This stage can distinguish those faces that differ significantly and it is robust to expression variations to some extent. On the basis of this step, we extract the SURF features of the 2D gray images, that are corresponding only to those highly ranked 3D faces, to carry out the refined recognition. The experiments indicated a high recognition rate by our procedure even when the face expressions of training samples differ greatly from testing samples.