Human-robot safety is an important topic in wearable robotics,especially in supernumerary robotic limbs(SRLs).The proposal of flexible joint improves human-robot safety strategy,which allows physical contact between h...Human-robot safety is an important topic in wearable robotics,especially in supernumerary robotic limbs(SRLs).The proposal of flexible joint improves human-robot safety strategy,which allows physical contact between human and robots,rather than strictly limiting the human-robot motion.However,most researchers focus on the variable stiffness features of flexible joints,but few evaluate the performance of the flexible joint in the human-robot collision.Therefore,the performance of two typical flexible joints,including the series elastic joint(SEJ)and the passive variable stiffness joint(PVSJ),are compared through dynamic collision experiments.The results demonstrate that the SEJ absorbs 40.7%-58.7%of the collision force and 34.2%-45.2%of the collision torque in the driven-torque below 4 N·m and driven-speed of 3-7(°)/s,which is more stable than PVSJ.In addition,the stiffness error of SEJ is measured at 5.1%,significantly lower than the 23.04%measured in the PVSJ.The huge stiffness error of PVSJ leads to its unreliability in buffering collision.Furthermore,we analyze results and confirm that SEJ has a more stable human-robot safety performance in buffering dynamic collision.Consequently,the SEJ is suitable in SRLs for human-robot safety in our scenario.展开更多
基金supported by the Na⁃tional Natural Science Foundation of China(No.U22A20204)the Innovation Foundation from National Clinical Research Center for Orthopedics,Sports Medicine&Rehabilitation Foundation(No.23-NCRC-CXJJ-ZD3-8)。
文摘Human-robot safety is an important topic in wearable robotics,especially in supernumerary robotic limbs(SRLs).The proposal of flexible joint improves human-robot safety strategy,which allows physical contact between human and robots,rather than strictly limiting the human-robot motion.However,most researchers focus on the variable stiffness features of flexible joints,but few evaluate the performance of the flexible joint in the human-robot collision.Therefore,the performance of two typical flexible joints,including the series elastic joint(SEJ)and the passive variable stiffness joint(PVSJ),are compared through dynamic collision experiments.The results demonstrate that the SEJ absorbs 40.7%-58.7%of the collision force and 34.2%-45.2%of the collision torque in the driven-torque below 4 N·m and driven-speed of 3-7(°)/s,which is more stable than PVSJ.In addition,the stiffness error of SEJ is measured at 5.1%,significantly lower than the 23.04%measured in the PVSJ.The huge stiffness error of PVSJ leads to its unreliability in buffering collision.Furthermore,we analyze results and confirm that SEJ has a more stable human-robot safety performance in buffering dynamic collision.Consequently,the SEJ is suitable in SRLs for human-robot safety in our scenario.
