Among the advantages of using industrial robots for machining applications instead of machine tools are flexibility, cost effectiveness, and versatility. Due to the kinematics of the articulated robot, the system beha...Among the advantages of using industrial robots for machining applications instead of machine tools are flexibility, cost effectiveness, and versatility. Due to the kinematics of the articulated robot, the system behaviour is quite different compared with machine tools. Two major questions arise in implementing robots in machining tasks: one is the robot’s stiffness, and the second is the achievable machined part accuracy, which varies mainly due to the huge variety of robot models. This paper proposes error prediction model in the application of industrial robot for machining tasks, based on stiffness and accuracy limits. The research work includes experimental and theoretical parts. Advanced machining and inspection tools were applied, as well as a theoretical model of the robot structure and stiffness based on the form-shaping function approach. The robot machining performances, from the workpiece accuracy point of view were predicted.展开更多
Soft robots face challenges in tunable stiffness due to flexibility-force transmission trade-offs.This paper presents a biomimetic linear tunable stiffness robot(LTSR)inspired by biological hydrostats and scales.LTSR ...Soft robots face challenges in tunable stiffness due to flexibility-force transmission trade-offs.This paper presents a biomimetic linear tunable stiffness robot(LTSR)inspired by biological hydrostats and scales.LTSR integrates a bellowsstructured soft driving actuator(SDA)mimicking hydrostatic organisms,enabling efficient axial elongation via fluid-mediated force transmission under constant-volume constraints,and overlapping jamming flaps inspired by biological scales,which enhance load-bearing capacity through adjustable interlayer friction.To maximize elongation performance,the kinematic model was established through equilibrium analysis of elastic and driving force,followed by a multi-objective optimization algorithm to identify optimal structural parameters.Theoretical predictions and finite element analysis(FEA)revealed that the optimized LTSR achieves over 200%greater elongation than the initial design.Experimental validation confirmed that the optimized SDA reaches 130.19 mm elongation at 50 kPa driving pressure,closely aligning with both theoretical and FEA results,thereby confirming model accuracy and superior motion performance.The stiffness model of LTSR was established through axial compression analysis to predict stiffness,with the median friction coefficients(FCs)of conventional sheets and the interlayer resisting force of bio-inspired adhesives incorporated.Comparative results revealed that using bio-inspired adhesives as jamming sheets yields significantly higher stiffness than using conventional jamming materials.The adhesion performance testing showed that the adhesive achieves its minimum macroscopic FC of 0.863 under an applied pressure of 471.81 Pa.Integrating these adhesive flaps into LTSR(forming B-LTSR)enabled load-responsive stiffness adjustment.BLTSR outperforms other soft robots with the highest stiffness and widest tunable range,validating the exceptional tunable stiffness of bio-inspired adhesive jamming flaps.Kinematic experiments show that B-LTSR retains 95.9%of SDA's elongation,demonstrating that the optimized bellows structure mitigates the mechanical constraint from the jamming components.The stiffening and softening response experiments indicate that B-LTSR can achieve rapid transitions between rigid and flexible states.展开更多
文摘Among the advantages of using industrial robots for machining applications instead of machine tools are flexibility, cost effectiveness, and versatility. Due to the kinematics of the articulated robot, the system behaviour is quite different compared with machine tools. Two major questions arise in implementing robots in machining tasks: one is the robot’s stiffness, and the second is the achievable machined part accuracy, which varies mainly due to the huge variety of robot models. This paper proposes error prediction model in the application of industrial robot for machining tasks, based on stiffness and accuracy limits. The research work includes experimental and theoretical parts. Advanced machining and inspection tools were applied, as well as a theoretical model of the robot structure and stiffness based on the form-shaping function approach. The robot machining performances, from the workpiece accuracy point of view were predicted.
基金supported by the Fundamental Research Funds for Central Universities(Grant No.B240201190)the Jiangsu Special Project for Frontier Leading Base Technology(Grant No.BK20192004)+2 种基金the Changzhou Social Development Science and Technology Support Project(Grant No.CE20225037)the Changzhou Science and Technology Project(Grant Nos.CM20223014,CJ20241061)the Suzhou Key Industrial Technology Innovation Forward-looking Application Research Project(Grant No.SYG202143)。
文摘Soft robots face challenges in tunable stiffness due to flexibility-force transmission trade-offs.This paper presents a biomimetic linear tunable stiffness robot(LTSR)inspired by biological hydrostats and scales.LTSR integrates a bellowsstructured soft driving actuator(SDA)mimicking hydrostatic organisms,enabling efficient axial elongation via fluid-mediated force transmission under constant-volume constraints,and overlapping jamming flaps inspired by biological scales,which enhance load-bearing capacity through adjustable interlayer friction.To maximize elongation performance,the kinematic model was established through equilibrium analysis of elastic and driving force,followed by a multi-objective optimization algorithm to identify optimal structural parameters.Theoretical predictions and finite element analysis(FEA)revealed that the optimized LTSR achieves over 200%greater elongation than the initial design.Experimental validation confirmed that the optimized SDA reaches 130.19 mm elongation at 50 kPa driving pressure,closely aligning with both theoretical and FEA results,thereby confirming model accuracy and superior motion performance.The stiffness model of LTSR was established through axial compression analysis to predict stiffness,with the median friction coefficients(FCs)of conventional sheets and the interlayer resisting force of bio-inspired adhesives incorporated.Comparative results revealed that using bio-inspired adhesives as jamming sheets yields significantly higher stiffness than using conventional jamming materials.The adhesion performance testing showed that the adhesive achieves its minimum macroscopic FC of 0.863 under an applied pressure of 471.81 Pa.Integrating these adhesive flaps into LTSR(forming B-LTSR)enabled load-responsive stiffness adjustment.BLTSR outperforms other soft robots with the highest stiffness and widest tunable range,validating the exceptional tunable stiffness of bio-inspired adhesive jamming flaps.Kinematic experiments show that B-LTSR retains 95.9%of SDA's elongation,demonstrating that the optimized bellows structure mitigates the mechanical constraint from the jamming components.The stiffening and softening response experiments indicate that B-LTSR can achieve rapid transitions between rigid and flexible states.
