Ren Wentao

Control system for constant pressure metering of fluid sowing machine

A control system for constant pressure metering of fluid sowing machine was developed. Fluid sowing is a new way to save water against drought, to ensure the emergence rate and growing of the seedlings of the crop. But the level of the gel and seeds mixture in the tank will lower down and the rate of gel metered will decrease with the proceeding of sowing and this will reduce the uniformity of sowing. In this study, the metering pressure in the tank was maintained to a constant value with the air blast for agitating, by adding a pressure control system of magnetic float and solenoid to the experimental machine, which solves the problems in the process of fluid sowing. The mathematic model of the air rate for stabilizing the pressure with the metering process was established which can provide basis for the parameters design of the air blowing system of metering device of fluid sowing machine. The experiments on metered gel rate with and without the pressure stabilizing control system were conducted, the results showed the control system could significantly increase the uniformity and mean gel rate metered and it can meet the requirement of agricultural production.

Identification and location of corn seedling based on computer vision

A prerequisite for variable spray operations is to detect, identify and locate maize seedlings in the complex scenes of farmland rapidly and accurately. In this paper, Regular pattern in distribution and growth of the corn seedling by bunch planting but leaves of plant overlapped in field is carefully taken into account, with the image acquisition mode which the camera image plane parallelized to the ground, in order to obtain the center of maize seedling roots, over-segmentation block projection method based on position feature is employed to locate crown of maize seedlings with the image captured. So the coordinate of corn root can be indirectly obtained by means of principles of perspective in machine vision as well as growing characteristics of corn. Experiment shows that the positioning error by this method is less than 30mm, and the average time in processing an image with 640×512 pixels in MATLAB is less than 300ms.

Experimental study on areodynamic property and broadcasting sowing of sprouted rice seeds

Rice is one of the most important food crops in the world as well as in China. The growing patterns of rice are manually or mechanically seedling transplanting, potted seedling broadcasting, potted seedling transplanting, dry land or paddy field direct sowing, etc. Sprouted rice seed broadcasting is a new simple cultural technology based on direct sowing and potted seedling broadcasting. It can save seeds, time and labor, cost less and of higher production efficiency than manually transplanting of rice seedling. The disadvantages of sprouted rice seeds manually broadcasting are also analyzed in this paper. The aerodynamic property of sprouted rice seed was tested to provide parameters for developing sprouted seeds broadcasting machine and increase the distribution uniformity of pneumatically broadcasted sprouted seeds. The results showed that the floating speed and coefficient are related with the length of sprout and kernel weight of the sprouted seeds, the regression equation of the floating coefficient varying with the ratio of sprout length (SL) to kernel weight (KW) was derived and it can be used to determine the floating coefficient and floating speed of sprouted seeds within certain limit. The distribution uniformity test of pneumatic broadcasting with a machine for seedling broadcasting was conducted and the results showed that the uniformity can meet the requirement of agronomy specification and it had no mechanical damage to the sprout.

Dynamic testing for the seed tape tensions of the rice seed tape twisting machine

In order to test the seed tape tensions of the rice seed tape twisting machine during the process, a dynamic testing system for the seed tape tensions was designed composed by the tensions sensor, data acquisition controller and PC, etc. The dynamic performance test of the machine was done and the seed tape tensions in the different speed was test by using the virtual instrument technology. The time domain analysis of the seed tape tensions was done by applied analysis software. The results show that, the seed tape tensions in the moving could be test by using tensions sensor and the virtual instrument technology. It has the important meaning for the seed tape tensions of dynamic measurement. It provided the basis for the dynamic performance testing and parameters optimization of the rice seed tape twisting machine.

Matching location algorithm of corn image projection based on over-segmentation

Fast and accurate positioning of corn image is premise for variable spray between plants. In order to improve the real-time and stability of matching algorithm for complex scenes tracking in the field, firstly, over-segmenting method is applied to eliminate the interference of weeds and noise in this paper. Then, the datum template which is morphological stable root image is adopted to match and locate with the target block by projection method. This method greatly reduces the complexity of the conventional template-matching algorithm. Therefore, the adaptability and stability of location algorithm are greatly improved.