A new method of collision-free path plan integrated in virtual processing is developed to improve the efficiency of laser surface hardening on dies. The path plan is based on the premise of no collision and the optimi...A new method of collision-free path plan integrated in virtual processing is developed to improve the efficiency of laser surface hardening on dies. The path plan is based on the premise of no collision and the optimization object is the shortest path. The optimization model of collision-free path is built from traveling salesman problem （TSP）. Collision-free path between two machining points is calculated in configuration space （C-Space）. Ant colony optimization （ACO） algorithm is applied to TSP of all the machining points to find the shortest path, which is simulated in virtual environment set up by IGRIP software. Virtual machining time, no-collision report, etc, are put out atter the simulation. An example on autobody die is processed in the virtual platform, the simulation results display that ACO has perfect optimization effect, and the method of virtual processing with integration of collision-free optimal path is practical.展开更多
In this study,a new algorithm was proposed for edge extraction of greenhouse strawberry leaf in natural light based on the 4-level daubechies 5(‘db5’)wavelet decomposition.This algorithm adopts different segmentatio...In this study,a new algorithm was proposed for edge extraction of greenhouse strawberry leaf in natural light based on the 4-level daubechies 5(‘db5’)wavelet decomposition.This algorithm adopts different segmentation methods for the reconstructed images at different scales to erase the external background and the internal leaf vein interference.There were two advantages of this method.One was that it can provide the abstraction from different spaces to express a same image.The other one was that some image features are hard to be acquired in some scale spaces,while the features are easy to be obtained in other scale spaces.In this image process methods,the Otsu threshold segmentation was to obtain the binary image areas,and the Canny segmentation is to obtain the accurate gradient edges,then the morphological methods and the logical calculus methods were to avoid the fragments inside the leaf area and the adhesions outside the leaf area.Since the strawberry leaf images were different respectively,and the greenhouse optical radiation and reflection may cause local non-uniform illumination of leaf image,the pseudo canny edges of leaf image ere divided into three categories in this research.The first category was the external pseudo canny edges area of the first layer reconstructed leaf image,the second category was the internal pseudo canny edges area in highlight of the third layer reconstructed leaf image,the third category was the internal pseudo canny edges area of significantly different grayscale of the third layer reconstructed leaf image.The different processing methods were constructed for the three kinds of different texture features based on the multi scale reconstructed images,then the complete and the accurate leaf edges without interference were obtained.Finally,the multi scale method was simplified and a remarkably effective segmentation algorithm was deduced for the greenhouse strawberry leaf in natural light.展开更多
基金This project is supported by Great Device Development Project of Chinese Academy of Sciences, China(No.[1997]167)Knowledge Innovation Great Project of Chinese Academy of Sciences, China, in 2000-2003(No. KGCX1-11).
文摘A new method of collision-free path plan integrated in virtual processing is developed to improve the efficiency of laser surface hardening on dies. The path plan is based on the premise of no collision and the optimization object is the shortest path. The optimization model of collision-free path is built from traveling salesman problem （TSP）. Collision-free path between two machining points is calculated in configuration space （C-Space）. Ant colony optimization （ACO） algorithm is applied to TSP of all the machining points to find the shortest path, which is simulated in virtual environment set up by IGRIP software. Virtual machining time, no-collision report, etc, are put out atter the simulation. An example on autobody die is processed in the virtual platform, the simulation results display that ACO has perfect optimization effect, and the method of virtual processing with integration of collision-free optimal path is practical.
基金This work was supported by the Beijing‘Urban agriculture project group’program and was undertaken by China Agricultural University.
文摘In this study,a new algorithm was proposed for edge extraction of greenhouse strawberry leaf in natural light based on the 4-level daubechies 5(‘db5’)wavelet decomposition.This algorithm adopts different segmentation methods for the reconstructed images at different scales to erase the external background and the internal leaf vein interference.There were two advantages of this method.One was that it can provide the abstraction from different spaces to express a same image.The other one was that some image features are hard to be acquired in some scale spaces,while the features are easy to be obtained in other scale spaces.In this image process methods,the Otsu threshold segmentation was to obtain the binary image areas,and the Canny segmentation is to obtain the accurate gradient edges,then the morphological methods and the logical calculus methods were to avoid the fragments inside the leaf area and the adhesions outside the leaf area.Since the strawberry leaf images were different respectively,and the greenhouse optical radiation and reflection may cause local non-uniform illumination of leaf image,the pseudo canny edges of leaf image ere divided into three categories in this research.The first category was the external pseudo canny edges area of the first layer reconstructed leaf image,the second category was the internal pseudo canny edges area in highlight of the third layer reconstructed leaf image,the third category was the internal pseudo canny edges area of significantly different grayscale of the third layer reconstructed leaf image.The different processing methods were constructed for the three kinds of different texture features based on the multi scale reconstructed images,then the complete and the accurate leaf edges without interference were obtained.Finally,the multi scale method was simplified and a remarkably effective segmentation algorithm was deduced for the greenhouse strawberry leaf in natural light.
