Optimum design is a key approach to make full use of potential advantages of a parallel manipulator. The optimum design of multi-parameter parallel manipulators（more than three design parameters）, such as Stewart ma...Optimum design is a key approach to make full use of potential advantages of a parallel manipulator. The optimum design of multi-parameter parallel manipulators（more than three design parameters）, such as Stewart manipulator, relies on analysis based and algorithm based optimum design methods, which fall to be accurate or intuitive. To solve this problem and achieve both accurate and intuition, atlas based optimum design of a general Stewart parallel manipulator is established, with rational selection of design parameters. Based on the defined spherical usable workspace（SUW）, primary kinematic performance indices of the Stewart manipulator involving workspace and condition number are introduced and analyzed. Then, corresponding performance atlases are drawn with the established non-dimensional design space, and impact of joint distribution angles on the manipulator performance is analyzed and illustrated. At last, an example on atlas based optimum design of the Stewart manipulator is accomplished to illustrate the optimum design process, considering the end-effector posture. Deduced atlases can be flexibly applied to both quantitative and qualitative analysis to get the desired optimal design for the Stewart manipulator with respect to related performance requirements. Besides, the established optimum design method can be further applied to other multi-parameter parallel manipulators.展开更多
以皂荚胚乳片为原料,以环氧丙烷为改性试剂,利用微水固相法制备羟丙基皂荚多糖,确立了最佳条件,即:皂荚多糖胶胚乳片10 g,加入10 m L 6%Na OH溶液,在35℃下搅拌碱化30 min,再加入2 m L的环氧丙烷,待胚乳片完全润胀,使用三辊研磨机将皂...以皂荚胚乳片为原料,以环氧丙烷为改性试剂,利用微水固相法制备羟丙基皂荚多糖,确立了最佳条件,即:皂荚多糖胶胚乳片10 g,加入10 m L 6%Na OH溶液,在35℃下搅拌碱化30 min,再加入2 m L的环氧丙烷,待胚乳片完全润胀,使用三辊研磨机将皂荚多糖胶的胚乳片压制成雪花片状,并放入反应器中进行醚化反应,控制反应温度为60℃和反应时间4 h。制备得到的羟丙基皂荚多糖水≤4.0%;表观粘度(1%溶液)≥1 500 m Pa·s;羟丙基取代度≥0.3; p H(1%溶液) 6.5～7.5。展开更多
基金Supported by National Natural Science Foundation of China(Grant Nos.51205224,51475252)National Outstanding Youth Science Foundation of China(Grant No.51225503)
文摘Optimum design is a key approach to make full use of potential advantages of a parallel manipulator. The optimum design of multi-parameter parallel manipulators（more than three design parameters）, such as Stewart manipulator, relies on analysis based and algorithm based optimum design methods, which fall to be accurate or intuitive. To solve this problem and achieve both accurate and intuition, atlas based optimum design of a general Stewart parallel manipulator is established, with rational selection of design parameters. Based on the defined spherical usable workspace（SUW）, primary kinematic performance indices of the Stewart manipulator involving workspace and condition number are introduced and analyzed. Then, corresponding performance atlases are drawn with the established non-dimensional design space, and impact of joint distribution angles on the manipulator performance is analyzed and illustrated. At last, an example on atlas based optimum design of the Stewart manipulator is accomplished to illustrate the optimum design process, considering the end-effector posture. Deduced atlases can be flexibly applied to both quantitative and qualitative analysis to get the desired optimal design for the Stewart manipulator with respect to related performance requirements. Besides, the established optimum design method can be further applied to other multi-parameter parallel manipulators.
文摘以皂荚胚乳片为原料,以环氧丙烷为改性试剂,利用微水固相法制备羟丙基皂荚多糖,确立了最佳条件,即:皂荚多糖胶胚乳片10 g,加入10 m L 6%Na OH溶液,在35℃下搅拌碱化30 min,再加入2 m L的环氧丙烷,待胚乳片完全润胀,使用三辊研磨机将皂荚多糖胶的胚乳片压制成雪花片状,并放入反应器中进行醚化反应,控制反应温度为60℃和反应时间4 h。制备得到的羟丙基皂荚多糖水≤4.0%;表观粘度(1%溶液)≥1 500 m Pa·s;羟丙基取代度≥0.3; p H(1%溶液) 6.5～7.5。
