声明
Table of Contents
摘要
Abstract
LIST OF TABLES
LIST OF FIGURES
CHAPTER Ⅰ：Introduction and review of rapeseed cultivation
1．1 Research problems
1．2 Status of Rapeseed Planting Technology
1．2．1 Overview of rapeseed planting and production
1．2．2 Rapeseed production mechanization
1．2．3 Planting date and density for increased yield
1．2．4 Disease control and management
1．2．5 Uses and expansion of rapeseed
1．3 Recent status of rapeseed planting technology
1．4 Precision planting operation
1．5 Previous studies on precision seeding operation
1．6 Research objectives and content
1．6．1 Research Objectives
1．6．2 Research contents
1．6．3 The research was intended to solve
CHAPTER Ⅱ：Design and experiment of a multi-rows pneumatic precision metering device for rapeseed
2．1 Introduction
2．2 Research objectives
2．3 Materials and Methods
2．3．1Physical properties of tested rapeseed
2．3．2 Structural parts and working principle of the metering device
2．3．3 Theory of seed metering operation
2．3．4 Experiment description and statistical method
2．4．Results and discussion
2．4．1 Effect of rotating speed(RS)on seed pick-up
2．4．2 Effects of negative pressure(NP)on seed pick-up
2．4．3 Effects of rotating speed(RS)and negative pressure(NP)on seed pick-up
2．4．4 Effects of RS，NP and rows on seed pick-up mass
2．5 Design of a whole planting machine for rapeseed
2．6 Chapter Conclusions
CHAPTER Ⅲ：An evaluation of seed spacing accuracy of a multi-rows pneumatic plate for precision rapeseed
3．1 Introduction
3．2 objectives
3．3 Materials and methods
3．3．1 Plastic slice for vacuum reduction around rows with multiple pick-up
3．3．2 Experiment description and statistical method
3．3．3 Seed spacing evaluation
3．4 Results and discussion
3．4．1Effect of clearance between plastic slice and plate surface on seed pick-up
3．4．2 Effect of 1mm clearance on rows seed distribution uniformity
3．4．3 Stability of rows quality index，miss index，and multiple index
3．5 Chapter conclusions
CHAPTER Ⅳ：Performance evaluation of three devices for rapeseed pick-up regularity of multi-rows pneumatic plate
4．1 Introduction
4．2 Objectives
4．3 Materials and methods
4．3．1The devices used with the methods and their working principle
4．3．2 Experiment description and statistical method
4．4 Results and discussion
4．4．1 Effects of 1mm and 2mm clearances on rows’ seed pick-up
4．4．2Effect of the curved-edges device on rows’ seed pick-up
4．4．3Effect of positive pressure application on rows’ seed pick-up
4．4．4 Comparison of the three methods
4．5 Chapter conclusions
CHAPTER Ⅴ：A vacuum distribution device for seed pick-up regularity improvement of a multi-rows pneumatic plate
5．1 Introduction
5．2 objectives
5．3 Materials and methods
5．3．1 Structure and working principle of vacuum distribution device
5．3．2 Experiment description and Statistical method
5．4 Resuits and discussion
5．4．1 Effect of vacuum levels and speeds on rows pick-up performance at 30° opening angle
5．4．2Effect of vacuum opening angle(size)on rows pick-up similarity
5．4．3 Effect of special adjustment of vacuum opening angle on rows sucking performance
5．5 Chapter Conclusions
CHAPTER Ⅵ：Rapeseed planting machine and field test
6．1 Introduction
6．2 Objectives
6．3 Planting machine and field experiment
6．4 Field data collection and analysis
6．5 Chapter conclusions
CHAPTER Ⅶ：Summary and outlooks
7．1 Summary
7．2 Innovations
7．3 Outlooks and future prospects
REFERENCES
APPENDIXES
ACKNOWLEGEMENTS
