Development and Application of the Intelligent Seed Processing Technology and Equipment

Seed processing is an important link in the seed industry chain. Crop seed industry is a national strategic and basic core of industry. Drying, cleaning, selecting, grading, coating, packaging and storage of crop seeds are the main measures to realize the precision sowing of crops and the increase of grain yield and income. Continuously improving the intelligence and fi ne level of seed processing equipment is of great signifi cance to ensure the production and supply of excellent seeds and the stability of agricultural production. This paper describes the development status of modern seed processing equipment technology in China, introduces the establishment of seed processing equipment engineering technology research center, taking maize, rice, wheat and cotton seed processing technology and machinery as an example, describes the key technologies and technological process of the breakthrough in the major crop seed processing, analyzes the existing problems of seed processing equipment in China at this stage as well as the development trend in the future, provides a reference for government decision makers in resolving the problem of mechanical damage in the process of seed processing and further improving the intellectualization level of seed processing, promotes the common progress of the global seed processing equipment technology.

P resident Jinping Xi put forward, "we must promote the mechanization and intelligence of agriculture vigorously, and add wings of science and technology for agricultural modernization". "One seed can change the world, the bowls of the Chinese, in any situation, must be firmly held in our own hands, and it should be mainly filled with Chinese grain" [1].
Crop seed industry is a national strategic and basic core of industry. Seed processing equipment is an important link in its industrial chain, which is the main measure to realize precision sowing and the increase of grain yield. Seed processing mainly refers to the seed treatments before planting and the fine processing, drying and storage of the grain after harvest (Fig. 1).
Seed processing refers to the process of drying, cleaning, grading, coating, packaging and storage of seeds from harvest to sowing depending on their different biological, physical and mechanical characteristics.
Seed processing equipment is the generic term of specialized processing technology and technical equipment which are designed and adopted for the different breeds of crop and processing requirements. Seed processing equipment is of special significance to ensure the production of fine seeds supply and the stability of agricultural production [2].

Development and application of intelligent seed processing technology and equipment
The National engineering technology research center of seed processing equipment was approved by the ministry of science and technology in 2012, established on Aokai Seed machinery Co., Ltd. Jiuquan, China (Fig. 2). It mainly engaged in the research of the principle of seed processing technology, the key technology of seed processing, the serialization, complete set, and intelligence for the seed processing equipment.
Aokai Seed machinery Co., Ltd. is close to the core area of national corn seed production base, and it is the largest leading enterprise of seed industrial equipment development and manufacture, ranking first in the industry in China. The main products are seed fine processing, seed drying, metal storage, field seed production, environmental protection and dust removal,and other 10 series included more than 500 varieties.
After the implementation of "seed law" in China, the number of seed enterprises in China has decreased from more than 8000 to less than 4000 now. The concentration of seed enterprises has been continuously improved, and the enterprises march toward the road of the large-scale management, which ensured the quality of seed processing and the safety of seed supply [3]. We have realized the industrialization, complete set, large-scale and intelligent of the seed processing in the standardizing, large-scale, mechanized and intensive environment. We pay attention to the seed health, preserve the seed vitality and ensure the processing quality [4].
The production line of the seed processing equipment is mainly divided into corn, rice, wheat, cotton, vegetable and flower seeds [5][6][7]. In China, corn seed production is a huge industry. In the field of the process of the corn seeds, we have built an intelligent mechanized operation in the whole process, and the mode of the largescale production (Fig. 5). We developed the complete set of equipment for large-scale processing of corn seeds. We realized the information management, fine processing, mechanized operation and large-scale production of corn seeds. We provided the mechanized processing equipment of the corn seeds with high cost performance, intelligent, large-scale, engineering in the whole process for seed industry in China.
In terms of the product research and development, according to the processing characteristics of the corn seeds, we have successfully developed large modular corn ear drying equipment, variable temperature drying equipment, intelligent seed sorting and processing equipment, multi-channel corn peeling machine, kneading maize sheller, intelligent batch environmental coating machine and other equipment, forming an advanced and perfect corn seed processing technology and equipment system.
In the application of new technology, the automatic control and information management system of the corn ear drying were researched. Through tracking and analyzing the collected data and corresponding curves, the best drying process parameters for the certain corn seeds were defined (Fig. 6). The remote monitoring and intelligent control of corn ear drying were realized, which reduces the intensity of the operators, and realizes the information recording and administration of the whole process of drying.
In the aspect of intelligent batch seed coating machine, based on PLC, the units are controlled to operate automatically, orderly, and concordantly, which realize the intelligent and precise addition of the seed coating agent. The pre-mixing system of seed coating agent was developed to solve the problems of various kinds and complex formulations of the seed coating agent.
We have developed an integrated high-clearance self-propelled corn tasseling and spraying equipment, based on the Beidou navigation system, it achieve automatic navigational operation of the spraying machine, which solves the problem of the intelligent control of the mechanized tasseling, spraying, fertilization, reduces the production cost of the corn seed production, and improves

КИТАЙСКО-РОССИЙСКИЙ СИМПОЗИУМ
SINO-RUSSIAN SYMPOSIUM the competitiveness of the seed market.The layout of largescale corn seed processing plant is constructed. We can develop one-stop solutions from plan, design, manufacture and install. We can complete the integrated turnkey project from the front unloading platform -ear dressing workshop -ear drying -threshing -temporary storagecleaning processing -intelligent storage (Fig. 7).
In terms of popularization and application, the annual production of the seed production of hybrid maize in the base in Hexi corridor, Gansu, accounts for about 60% of the national demand. The purification rate of corn seeds reaches 99.5%, the damage rate is less than 0.5%, and the germination rate is more than 96%. At present, there are 150 corn ear drying production lines in China, which effectively guarantee the large-scale processing demand of corn seeds.
In the field of rice and wheat seed processing, we mainly solve the problems of processing equipment and intelligent control system, such as precleaning, grain drying, awning removal, gravity separation, pit-hole roller cleaning, specific gravity wind separation, coating and packaging (Fig. 8). In recent years, the demand of the mechanical drying of rice seeds is increasing by year. There are more than 1200 complete sets of wheat and rice seed processing lines in China, which basically meet the current processing requirements of rice seeds in China [8].
The continuous intelligent drying technology of rice and wheat grain were mainly solved. According to the safety temperature of different materials tolerated, the variable temperature drying process was adopted to realize the slow and uniform precipitation of rice and wheat seeds, and reduce the rate of cracking and heat damage of seeds.
In terms of heat source, heat pump is used as clean heat source to change the traditional drying mode which uses coal as heat source. Large rice dryers with 15 t/h, 30 t/h and even 100 t/h have been developed and produced. The drying temperature is accurately controlled, and energy saving, environmental protection and reduced seed drying cost are achieved.
In the aspect of cotton seed processing, the excessive dilute sulfuric acid depilation process was used to build a complete production line of intelligent de cashing of cotton seeds. After processing, the purity of cotton seeds was more than 95%, the germination rate was more than 90%, and the crushing rate was less than 5%. China has built 120 complete sets of cotton seed production lines.
In recent years, color separation and magnetic separation technology have been continuously applied in processing production line of cotton seeds, which significantly improve the quality of cotton seeds. Color separation technology is also suitable for the processing production line of rice and corn seeds.
In the field of seed processing of vegetable, flower and forage seeds, a production line with a processing capacity of 150 kg/h has been developed, which has solved the key technologies of the fine processing single machine and complete set of production regarding polishing, drying, wind separation, specific gravity selection, coating of the vegetables, flowers and grasses seeds. It also provides key technical equipment for the fine processing of vegetable and flower seeds in China.
Seed processing technology in china originated in the 1970s and has a history of 50 years. The development of seed industry equipment has gone through a process from scratch less to much more, small to large, single to complete. The development of seed industry equipment has basically met the needs of China's seed processing equipment, and has been exported to many countries around the world. The technical level of seed industry equipment has reached the international advanced level, which can play an important role in solving the problem of the grain yield, farmers' income, and the eating problems of 1.4 billion people in China.
The future of seed processing To solve the problem of mechanical seed damage during seed processing, the level of the intelligence in seed process should be further improved. The deep integration of 5G with cloud computing, big data, artificial intelligence, virtual reality and other technologies to establish seed processing parameter database and realize online remote intelligent control of seed process is the goal of the research and development of seed processing equipment in the future.
Quality traceability and on-line monitoring of seed production process should be solved. Machine vision technology, near infrared spectroscopy, hyper-spectral imaging technology, soft X-ray technology, laser speckle technology and other technical means should be applied to detect seed vitality and vigor.