Song Yuqiu

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.

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.

Process control system for scion and rootstock feeding of vegetable grafting machine

A vegetable grafting machine was designed which employed the method of splice grafting. The feeding of scion and rootstock in certain sequence is the key part of the machine and the structure, motion and accuracy of the feeding system decide the grafting productivity and quality. The operation process was determined in this study and the scion and rootstock feeding system was designed. A pneumatic system was utilized as the power of opening and closing of feeding manipulator, and a step motor was used to drive the feeding system to turn intermittently. An 89C51 Single Chip Microprocessor (SCM) was employed and programmed to realize the process control for the scion and rootstock feeding and the operation of the related cutting, conveying system, etc. The test showed that the grafting machine can realize the programmed function. The productivity is 450 grafted plants per hour.