Development of machine-vision system for gap inspection of muskmelon grafted seedlings.

Grafting robots have been developed in the world, but some auxiliary works such as gap-inspecting for grafted seedlings still need to be done by human. An machine-vision system of gap inspection for grafted muskmelon seedlings was developed in this study. The image acquiring system consists of a CCD camera, a lens and a front white lighting source. The image of inspected gap was processed and analyzed by software of HALCON 12.0. The recognition algorithm for the system is based on principle of deformable template matching. A template should be created from an image of qualified grafted seedling gap. Then the gap image of the grafted seedling will be compared with the created template to determine their matching degree. Based on the similarity between the gap image of grafted seedling and the template, the matching degree will be 0 to 1. The less similar for the grafted seedling gap with the template the smaller of matching degree. Thirdly, the gap will be output as qualified or unqualified. If the matching degree of grafted seedling gap and the template is less than 0.58, or there is no match is found, the gap will be judged as unqualified; otherwise the gap will be qualified. Finally, 100 muskmelon seedlings were grafted and inspected to test the gap inspection system. Results showed that the gap inspection machine-vision system could recognize the gap qualification correctly as 98% of human vision. And the inspection speed of this system can reach 15 seedlings·min-1. The gap inspection process in grafting can be fully automated with this developed machine-vision system, and the gap inspection system will be a key step of a fully-automatic grafting robots

Influence of plasma remelting conditions on quantitative graphite dissolution and modified surface characteristics in 500-12 ductile iron

In this study, the influence of multi-pass plasma remelting conditions on quantitative graphite nodules dissolution, surface hardening and wear resistance of 500-12 ductile iron was evaluated. Surface remelting was carried out at various levels of heat inputs using high-temperature plasma beams. The graphite dissolution was uniquely quantified via image analysis approach, and then the remelted surface layer was characterized for phase transformation, microstructure, hardness and wear resistance. The remelting process parameters (arc current and scanning speed) showed significant (p < 0.01) influence, both on graphite nodules dissolution and surface hardening. Consequently, microstructure of the treated layer is modified and the surface exhibited a significant improvement in hardness and wear resistance. In addition, treatment conditions having slower scanning speed showed better surface modification. Therefore, the plasma remelting enhanced surface hardness and dry sliding wear resistance of 500-12 ferrictic ductile cast iron, which makes it suitable for application in a severe wear condition

The output of the program algorithm displayed on the interface.

<p>The output of the program algorithm displayed on the interface.</p

Possible result of researching for template in the target image.

<p>Possible result of researching for template in the target image.</p

Flowchart of template matching process.

<p>Flowchart of template matching process.</p

The illumination schemes for the experiment.

<p>The illumination schemes for the experiment.</p

Image acquisition layout.

<p>Image acquisition layout.</p

Sample results of searching for the template in the target grafted gap images.

<p>Sample results of searching for the template in the target grafted gap images.</p

Images of seedling stem from lenses with different focal lengths.

<p>Images of seedling stem from lenses with different focal lengths.</p

CCD camera MER-125-30UC performance parameters table.

<p>CCD camera MER-125-30UC performance parameters table.</p