In a tractor automatic navigation system, path planning plays a significant role in improving operation efficiency. This study aims to create a suboptimal reference course for headland turning of a robot tractor and d...In a tractor automatic navigation system, path planning plays a significant role in improving operation efficiency. This study aims to create a suboptimal reference course for headland turning of a robot tractor and design a path-tracking controller to guide the robot tractor along the reference course. A time-minimum suboptimal control method was used to generate the reference turning course based on the mechanical parameters of the test tractor. A path-tracking controller consisting of both feedforward and feedback component elements was also proposed. The feedforward component was directly determined by the desired steering angle of the current navigation point on the reference course, whereas the feedback component was derived from the designed optimal controller. Computer simulation and field tests were performed to validate the path-tracking performance. Field test results indicated that the robot tractor followed the reference courses precisely on flat meadow, with average and standard lateral devia- tions being 0.031 m and 0.086 m, respectively. However, the tracking error increased while operating on sloping meadow due to the employed vehicle kinematic model.展开更多
In this paper,using the research method of grounded theory,with the competitive brand of home gardening—Hongyue Garden Maker as the specific object of study,we collect the data through interviews and surveys,conduct ...In this paper,using the research method of grounded theory,with the competitive brand of home gardening—Hongyue Garden Maker as the specific object of study,we collect the data through interviews and surveys,conduct coding analysis step by step on the data,establish the brand asset creation path model consisting of some main dimensions including " brand salience"," brand performance"," brand image"," brand judgment"," brand feeling",and " brand resonance",and reveal the interaction and logical relationship between the above dimensions,so as to provide theoretical support for the asset creation of many kinds of home gardening and other brands.展开更多
This study analyzes opportunity recognition and development from the perspective of job embeddedness based on entrepreneurial action of tech-entrepreneur. The impact of job embeddedness to entrepreneurial path choice ...This study analyzes opportunity recognition and development from the perspective of job embeddedness based on entrepreneurial action of tech-entrepreneur. The impact of job embeddedness to entrepreneurial path choice of tech-entrepreneur is tested by multi-case study. This paper also provides theoretic evidence to enhance the possibility of success of start-ups for entrepreneurs.展开更多
基金Project (No. 2006AA10A304) supported by the Hi-Tech Researchand Development Program (863) of China
文摘In a tractor automatic navigation system, path planning plays a significant role in improving operation efficiency. This study aims to create a suboptimal reference course for headland turning of a robot tractor and design a path-tracking controller to guide the robot tractor along the reference course. A time-minimum suboptimal control method was used to generate the reference turning course based on the mechanical parameters of the test tractor. A path-tracking controller consisting of both feedforward and feedback component elements was also proposed. The feedforward component was directly determined by the desired steering angle of the current navigation point on the reference course, whereas the feedback component was derived from the designed optimal controller. Computer simulation and field tests were performed to validate the path-tracking performance. Field test results indicated that the robot tractor followed the reference courses precisely on flat meadow, with average and standard lateral devia- tions being 0.031 m and 0.086 m, respectively. However, the tracking error increased while operating on sloping meadow due to the employed vehicle kinematic model.
基金Supported by National College Students'Innovation and Entrepreneurship Training Program in 2017(103-2013200072)National Social Science Fund Project(15BGL088)Zhejiang Higher Education Reform Project in 2016(jg20160092)
文摘In this paper,using the research method of grounded theory,with the competitive brand of home gardening—Hongyue Garden Maker as the specific object of study,we collect the data through interviews and surveys,conduct coding analysis step by step on the data,establish the brand asset creation path model consisting of some main dimensions including " brand salience"," brand performance"," brand image"," brand judgment"," brand feeling",and " brand resonance",and reveal the interaction and logical relationship between the above dimensions,so as to provide theoretical support for the asset creation of many kinds of home gardening and other brands.
基金supported by SHANNXI Social Science Foundation(10Q067)Ministry of Education Social Science and Humanities Foundation(12YJA630187)High Education Research Fund of Northwestern Polytechnical University(2014)
文摘This study analyzes opportunity recognition and development from the perspective of job embeddedness based on entrepreneurial action of tech-entrepreneur. The impact of job embeddedness to entrepreneurial path choice of tech-entrepreneur is tested by multi-case study. This paper also provides theoretic evidence to enhance the possibility of success of start-ups for entrepreneurs.