With the target at simplicity like facilitating the mechanical system,the quadruped robots usually have limited degrees of freedom per leg.Addressing the robot whose legs have only two degrees of freedom,this paper ex...With the target at simplicity like facilitating the mechanical system,the quadruped robots usually have limited degrees of freedom per leg.Addressing the robot whose legs have only two degrees of freedom,this paper explores several turning strategies including altering the median value,changing the phase difference,and modifying the amplitude.The insights of the proposed methods are that we break down the symmetries which exist during the process of the robot locomotion and rebuild them.Since we probe into the turning feasibility from the points of the median value,phase difference and amplitude in the sine functions,these turning methods are feature of universality.In order to evaluate these methods,this paper presents a new way to weigh the stability,which can be easily applied to practical robots.Experiments demonstrate that the quadruped turns around with little effort and endeavor.展开更多
Tin bronze wires were produced by dieless drawing. The effects of heating power, the distance between cooler and heater as well as feeding speed on the diameter, the temperature field, and the deformation region profi...Tin bronze wires were produced by dieless drawing. The effects of heating power, the distance between cooler and heater as well as feeding speed on the diameter, the temperature field, and the deformation region profile of the wires were investigated. The results indi-cated that each processing parameter exhibited both lower and upper limits of stable deformation based on the criterion of stable deformation with the diameter fluctuation of ±0.05 mm. Both the temperature and its gradient of the deformation region increased with increasing heating power under stable deformation, but decreased with an increase in feeding speed. As the distance between cooler and heater increased, the temperature of the deformation region increased and the slope of the deformation region profile decreased. The processing limit map of sta-ble deformation exhibited a closed curve and the unstable deformation consisted of wire breakage and diameter fluctuations.展开更多
文摘With the target at simplicity like facilitating the mechanical system,the quadruped robots usually have limited degrees of freedom per leg.Addressing the robot whose legs have only two degrees of freedom,this paper explores several turning strategies including altering the median value,changing the phase difference,and modifying the amplitude.The insights of the proposed methods are that we break down the symmetries which exist during the process of the robot locomotion and rebuild them.Since we probe into the turning feasibility from the points of the median value,phase difference and amplitude in the sine functions,these turning methods are feature of universality.In order to evaluate these methods,this paper presents a new way to weigh the stability,which can be easily applied to practical robots.Experiments demonstrate that the quadruped turns around with little effort and endeavor.
基金supported by the National Basic Research Priorities Program of China (No.2006CB605200)the National Natural Science Foundation of China (No.50634010, 50674008)+1 种基金the Program for New Century Excellent Talents in Chinese Universities (No.NCET-06-0083)the Universities Fundamental Research Foundation of MOE (No FRF-TP-10-002B)
文摘Tin bronze wires were produced by dieless drawing. The effects of heating power, the distance between cooler and heater as well as feeding speed on the diameter, the temperature field, and the deformation region profile of the wires were investigated. The results indi-cated that each processing parameter exhibited both lower and upper limits of stable deformation based on the criterion of stable deformation with the diameter fluctuation of ±0.05 mm. Both the temperature and its gradient of the deformation region increased with increasing heating power under stable deformation, but decreased with an increase in feeding speed. As the distance between cooler and heater increased, the temperature of the deformation region increased and the slope of the deformation region profile decreased. The processing limit map of sta-ble deformation exhibited a closed curve and the unstable deformation consisted of wire breakage and diameter fluctuations.
