针对压电柔性机械臂运行过程中的弹性振动问题,提出了基于粒子群优化算法(particle swarm optimization,简称PSO)自整定比例积分微分(proportional integral differential,简称PID)控制器参数的柔性臂振动抑制方法。采用标准粒子群优化...针对压电柔性机械臂运行过程中的弹性振动问题,提出了基于粒子群优化算法(particle swarm optimization,简称PSO)自整定比例积分微分(proportional integral differential,简称PID)控制器参数的柔性臂振动抑制方法。采用标准粒子群优化算法,以时间乘绝对误差积(integrated time and absolute error,简称ITAE)准则为适应度函数,整定PID控制器的3个控制参数Kp,Ki和Kd,并采用Matlab Simulink平台建立双连杆压电柔性机械臂振动控制仿真模型,研制基于虚拟仪器技术的柔性臂振动控制试验系统。仿真与试验结果表明,采用常规PID控制算法和基于PSO自整定的PID控制算法均能有效地抑制柔性机械臂的弹性振动,但后者的振动抑制效果、鲁棒性与稳定性优于前者。展开更多
High-performance fiber-shaped power sources are anticipated to considerably contribute to the continuous development of smart wearable devices.As one-/two-dimensional(1D/2D)frameworks constructed from graphene sheets,...High-performance fiber-shaped power sources are anticipated to considerably contribute to the continuous development of smart wearable devices.As one-/two-dimensional(1D/2D)frameworks constructed from graphene sheets,graphene fibers and fabrics inherit the merits of graphene,including its lightweight nature,high electrical conductivity,and exceptional mechanical strength.The as-fabricated graphene fiber/fabric flexible supercapacitor(FSC)is,therefore,regarded as a promis-ing candidate for next-generation wearable energy storage devices owing to its high energy/power density,adequate safety,satisfactory flexibility,and extended cycle life.The gap between practical applications and experimental demonstrations of FSC is drastically reduced as a result of technological advancements.To this end,herein,recent advancements of FSCs in fiber element regulation,fiber/fabric construction,and practical applications are methodically reviewed and a forecast of their growth is presented.展开更多
A numerical method for coupled deformation between sheet metal and flexible-die was proposed. Based on the updated Lagrangian （UL） formulation, the elastoplastic deformation of sheet metal was analyzed with finite e...A numerical method for coupled deformation between sheet metal and flexible-die was proposed. Based on the updated Lagrangian （UL） formulation, the elastoplastic deformation of sheet metal was analyzed with finite element method （FEM） and the bulk deformation of flexible-die was analyzed with element-free Galerkin method （EFGM）. The frictional contact between sheet metal and flexible-die was treated by the penalty function method. The sheet elastic flexible-die bulging process was analyzed with the FEM-EFGM program for coupled deformation between sheet metal and bulk flexible-die, called CDSB-FEM-EFGM for short. Compared with finite element code DEFORM-2D and experiment results, the CDSB-FEM-EFGM program is feasible. This method provides a suitable numerical method to analyze sheet flexible-die forming.展开更多
For fragile products,packaging requires cushioning protection to prevent irreversible damage from accidental falls,transportation impacts,and other causes.The new polyurethane foam(PUF)material demonstrates superior c...For fragile products,packaging requires cushioning protection to prevent irreversible damage from accidental falls,transportation impacts,and other causes.The new polyurethane foam(PUF)material demonstrates superior cushioning and vibration isolation performance in practical applications,effectively minimizing damage from vibrations.Drop and vibration experiments were conducted on packages comprising novel PUF,expandable polyethylene,ethylene-vinyl acetate copolymer foam,and bracelets.Results verify that the new PUF material outperforms in cushioning and vibration isolation,as observed from the acceleration response.Furthermore,a random vibration analysis of a packaging unit involving different thicknesses of PUF materials and bracelets reveals the enhanced vibration isolation effect within a specific thickness range.The vibration results of the bracelet’s outer packaging align closely with finite element simulation results,validating the effectiveness of designing and optimizing the outer packaging.Through finite element simulation,deeper understanding and prediction of the bracelet’s vibration response under various conditions is achieved,facilitating optimized packaging design for better protection and vibration damping.展开更多
文摘针对压电柔性机械臂运行过程中的弹性振动问题,提出了基于粒子群优化算法(particle swarm optimization,简称PSO)自整定比例积分微分(proportional integral differential,简称PID)控制器参数的柔性臂振动抑制方法。采用标准粒子群优化算法,以时间乘绝对误差积(integrated time and absolute error,简称ITAE)准则为适应度函数,整定PID控制器的3个控制参数Kp,Ki和Kd,并采用Matlab Simulink平台建立双连杆压电柔性机械臂振动控制仿真模型,研制基于虚拟仪器技术的柔性臂振动控制试验系统。仿真与试验结果表明,采用常规PID控制算法和基于PSO自整定的PID控制算法均能有效地抑制柔性机械臂的弹性振动,但后者的振动抑制效果、鲁棒性与稳定性优于前者。
基金supported by the Natural Science Foundation of China(No.51425202,No.51772150)the Natural Science Foundation of Jiangsu Province(No.BK20211592,No.BK20160093)+1 种基金the Key Research and Development Program of Jiangsu Province(No.BE2016006-1)the Project Funded by the Priority Academic Program Development of Jiangsu Higher Education Institutions(PAPD).
文摘High-performance fiber-shaped power sources are anticipated to considerably contribute to the continuous development of smart wearable devices.As one-/two-dimensional(1D/2D)frameworks constructed from graphene sheets,graphene fibers and fabrics inherit the merits of graphene,including its lightweight nature,high electrical conductivity,and exceptional mechanical strength.The as-fabricated graphene fiber/fabric flexible supercapacitor(FSC)is,therefore,regarded as a promis-ing candidate for next-generation wearable energy storage devices owing to its high energy/power density,adequate safety,satisfactory flexibility,and extended cycle life.The gap between practical applications and experimental demonstrations of FSC is drastically reduced as a result of technological advancements.To this end,herein,recent advancements of FSCs in fiber element regulation,fiber/fabric construction,and practical applications are methodically reviewed and a forecast of their growth is presented.
基金Project(51275130)supported by the National Natural Science Foundation of China
文摘A numerical method for coupled deformation between sheet metal and flexible-die was proposed. Based on the updated Lagrangian （UL） formulation, the elastoplastic deformation of sheet metal was analyzed with finite element method （FEM） and the bulk deformation of flexible-die was analyzed with element-free Galerkin method （EFGM）. The frictional contact between sheet metal and flexible-die was treated by the penalty function method. The sheet elastic flexible-die bulging process was analyzed with the FEM-EFGM program for coupled deformation between sheet metal and bulk flexible-die, called CDSB-FEM-EFGM for short. Compared with finite element code DEFORM-2D and experiment results, the CDSB-FEM-EFGM program is feasible. This method provides a suitable numerical method to analyze sheet flexible-die forming.
基金the National Natural Science Foundation of China(Grant Numbers 12172151 and 12172149).
文摘For fragile products,packaging requires cushioning protection to prevent irreversible damage from accidental falls,transportation impacts,and other causes.The new polyurethane foam(PUF)material demonstrates superior cushioning and vibration isolation performance in practical applications,effectively minimizing damage from vibrations.Drop and vibration experiments were conducted on packages comprising novel PUF,expandable polyethylene,ethylene-vinyl acetate copolymer foam,and bracelets.Results verify that the new PUF material outperforms in cushioning and vibration isolation,as observed from the acceleration response.Furthermore,a random vibration analysis of a packaging unit involving different thicknesses of PUF materials and bracelets reveals the enhanced vibration isolation effect within a specific thickness range.The vibration results of the bracelet’s outer packaging align closely with finite element simulation results,validating the effectiveness of designing and optimizing the outer packaging.Through finite element simulation,deeper understanding and prediction of the bracelet’s vibration response under various conditions is achieved,facilitating optimized packaging design for better protection and vibration damping.
