Soft robots have become important members of the robot community with many potential applications owing to their unique flexibility and security embedded at the material level.An increasing number of researchers are i...Soft robots have become important members of the robot community with many potential applications owing to their unique flexibility and security embedded at the material level.An increasing number of researchers are interested in their designing,manufacturing,modeling,and control.However,the dynamic simulation of soft robots is difficult owing to their infinite degrees of freedom and nonlinear characteristics that are associated with soft materials and flexible geometric structures.In this study,a novel multi-flexible body dynamic modeling and simulation technique is introduced for soft robots.Various actuators for soft robots are modeled in a virtual environment,including soft cable-driven,spring actuation,and pneumatic driving.A pneumatic driving simulation was demonstrated by the bending modules with different materials.A cable-driven soft robot arm prototype and a cylindrical soft module actuated by shape memory alley springs inspired by an octopus were manufactured and used to validate the simulation model,and the experimental results demonstrated adequate accuracy.The proposed technique can be widely applied for the modeling and dynamic simulation of other soft robots,including hybrid actuated robots and rigid-flexible coupling robots.This study also provides a fundamental framework for simulating soft mobile robots and soft manipulators in contact with the environment.展开更多
In this paper, a formation control algorithm and an obstade avoidance control algorithm for mobile robots are developed based on a relative motion sensory system such as a pan/tilt camera vision system, without the ne...In this paper, a formation control algorithm and an obstade avoidance control algorithm for mobile robots are developed based on a relative motion sensory system such as a pan/tilt camera vision system, without the need for global sensing and between robots. This is achieved by employing the velocity variation, instead of actual velocities, as the control inputs. Simulation and experimental results have demonstrated the effectiveness of the proposed control methods.展开更多
Quality assurance and maintenance play a crucial role in engineering construction,as they have a significant impact on project safety.One common issue in concrete structures is the presence of defects.To enhance the a...Quality assurance and maintenance play a crucial role in engineering construction,as they have a significant impact on project safety.One common issue in concrete structures is the presence of defects.To enhance the automation level of concrete defect repairs,this study proposes a computer vision-based robotic system,which is based on three-dimensional(3D)printing technology to repair defects.This system integrates multiple sensors such as light detection and ranging(LiDAR)and camera.LiDAR is utilized to model concrete pipelines and obtain geometric parameters regarding their appearance.Additionally,a convolutional neural network(CNN)is employed with a depth camera to locate defects in concrete structures.Furthermore,a method for coordinate transformation is presented to convert the obtained coordinates into executable ones for a robotic arm.Finally,the feasibility of this concrete defect repair method is validated through simulation and experiments.展开更多
Background:Following the short-term outbreak of coronavirus disease 2019(COVID-19)in December 2022 in China,clinical data on kidney transplant recipients(KTRs)with COVID-19 are lacking.Methods:We conducted a single-ce...Background:Following the short-term outbreak of coronavirus disease 2019(COVID-19)in December 2022 in China,clinical data on kidney transplant recipients(KTRs)with COVID-19 are lacking.Methods:We conducted a single-center retrospective study to describe the clinical features,complications,and mortality rates of hospitalized KTRs infected with COVID-19 between Dec.16,2022 and Jan.31,2023.The patients were followed up until Mar.31,2023.Results:A total of 324 KTRs with COVID-19 were included.The median age was 49 years.The median time between the onset of symptoms and admission was 13 d.Molnupiravir,azvudine,and nirmatrelvir/ritonavir were administered to 67(20.7%),11(3.4%),and 148(45.7%)patients,respectively.Twenty-nine(9.0%)patients were treated with more than one antiviral agent.Forty-eight(14.8%)patients were treated with tocilizumab and 53(16.4%)patients received baricitinib therapy.The acute kidney injury(AKI)occurred in 81(25.0%)patients and 39(12.0%)patients were admitted to intensive care units.Fungal infections were observed in 55(17.0%)patients.Fifty(15.4%)patients lost their graft.The 28-d mortality rate of patients was 9.0%and 42(13.0%)patients died by the end of follow-up.Multivariate Cox regression analysis identified that cerebrovascular disease,AKI incidence,interleukin(IL)-6 level of>6.8 pg/mL,daily dose of corticosteroids of>50 mg,and fungal infection were all associated with an increased risk of death for hospitalized patients.Conclusions:Our findings demonstrate that hospitalized KTRs with COVID-19 are at high risk of mortality.The administration of immunomodulators or the late application of antiviral drugs does not improve patient survival,while higher doses of corticosteroids may increase the death risk.展开更多
Focusing on the ball double-screw hydraulic knee joint as the research object,this paper analyzes the load driving performance of the hydraulic knee joint.Taking the posture data of the human body such as walking,squa...Focusing on the ball double-screw hydraulic knee joint as the research object,this paper analyzes the load driving performance of the hydraulic knee joint.Taking the posture data of the human body such as walking,squatting and landing buffer as initial learning objects,motion features are extracted.By simplifying the trajectories of different motion actions into key feature control points and flexible trajectory fitting,the trajectory of joint actions is optimized.This method can realize the adaptability of the hydraulic robot knee joint in different movements,and take the flexible action as the optimization goal under the condition of ensuring the movement performance,so as to reduce the damage to the knee joint caused by the foot impact in motion.The simulation model was built by Adams and Matlab to complete the performance analysis and motion optimization experiment of the knee joint.The simulation results show that the foot impact force of the experimental model decreases gradually through optimization.Finally,the method is applied to the hydraulic joint experimental prototype to prove its load capacity and flexible motion control performance.展开更多
基金Supported by the National Natural Science Foundation of China(Grant Nos.51822502 and 91948202)the National Key Research and Development Program of China(No.2019YFB1309500)the“111 Project”(Grant No.B07018).
文摘Soft robots have become important members of the robot community with many potential applications owing to their unique flexibility and security embedded at the material level.An increasing number of researchers are interested in their designing,manufacturing,modeling,and control.However,the dynamic simulation of soft robots is difficult owing to their infinite degrees of freedom and nonlinear characteristics that are associated with soft materials and flexible geometric structures.In this study,a novel multi-flexible body dynamic modeling and simulation technique is introduced for soft robots.Various actuators for soft robots are modeled in a virtual environment,including soft cable-driven,spring actuation,and pneumatic driving.A pneumatic driving simulation was demonstrated by the bending modules with different materials.A cable-driven soft robot arm prototype and a cylindrical soft module actuated by shape memory alley springs inspired by an octopus were manufactured and used to validate the simulation model,and the experimental results demonstrated adequate accuracy.The proposed technique can be widely applied for the modeling and dynamic simulation of other soft robots,including hybrid actuated robots and rigid-flexible coupling robots.This study also provides a fundamental framework for simulating soft mobile robots and soft manipulators in contact with the environment.
文摘In this paper, a formation control algorithm and an obstade avoidance control algorithm for mobile robots are developed based on a relative motion sensory system such as a pan/tilt camera vision system, without the need for global sensing and between robots. This is achieved by employing the velocity variation, instead of actual velocities, as the control inputs. Simulation and experimental results have demonstrated the effectiveness of the proposed control methods.
基金This research was funded by the Ministry of Science and Technology of China(No.2021YFE0114100)the Science and Technology Commission of Shanghai Municipality(No.21DZ1203505)the Top Discipline Plan of Shanghai Universities-Class I.
文摘Quality assurance and maintenance play a crucial role in engineering construction,as they have a significant impact on project safety.One common issue in concrete structures is the presence of defects.To enhance the automation level of concrete defect repairs,this study proposes a computer vision-based robotic system,which is based on three-dimensional(3D)printing technology to repair defects.This system integrates multiple sensors such as light detection and ranging(LiDAR)and camera.LiDAR is utilized to model concrete pipelines and obtain geometric parameters regarding their appearance.Additionally,a convolutional neural network(CNN)is employed with a depth camera to locate defects in concrete structures.Furthermore,a method for coordinate transformation is presented to convert the obtained coordinates into executable ones for a robotic arm.Finally,the feasibility of this concrete defect repair method is validated through simulation and experiments.
基金supported by the National Natural Science Foundation of China(No.2022YFC82200842)the Zhejiang Provincial Natural Science Foundation of China(No.LQ22H050004).
文摘Background:Following the short-term outbreak of coronavirus disease 2019(COVID-19)in December 2022 in China,clinical data on kidney transplant recipients(KTRs)with COVID-19 are lacking.Methods:We conducted a single-center retrospective study to describe the clinical features,complications,and mortality rates of hospitalized KTRs infected with COVID-19 between Dec.16,2022 and Jan.31,2023.The patients were followed up until Mar.31,2023.Results:A total of 324 KTRs with COVID-19 were included.The median age was 49 years.The median time between the onset of symptoms and admission was 13 d.Molnupiravir,azvudine,and nirmatrelvir/ritonavir were administered to 67(20.7%),11(3.4%),and 148(45.7%)patients,respectively.Twenty-nine(9.0%)patients were treated with more than one antiviral agent.Forty-eight(14.8%)patients were treated with tocilizumab and 53(16.4%)patients received baricitinib therapy.The acute kidney injury(AKI)occurred in 81(25.0%)patients and 39(12.0%)patients were admitted to intensive care units.Fungal infections were observed in 55(17.0%)patients.Fifty(15.4%)patients lost their graft.The 28-d mortality rate of patients was 9.0%and 42(13.0%)patients died by the end of follow-up.Multivariate Cox regression analysis identified that cerebrovascular disease,AKI incidence,interleukin(IL)-6 level of>6.8 pg/mL,daily dose of corticosteroids of>50 mg,and fungal infection were all associated with an increased risk of death for hospitalized patients.Conclusions:Our findings demonstrate that hospitalized KTRs with COVID-19 are at high risk of mortality.The administration of immunomodulators or the late application of antiviral drugs does not improve patient survival,while higher doses of corticosteroids may increase the death risk.
基金supported by the Top Discipline Plan of Shanghai Universities-Class I,the National Natural Science Foundation of China(52205279)the China National Postdoctoral Program for Innovative Talents(BX20190242)+1 种基金the Open Foundation of the State Key Laboratory of Fluid Power and Mechatronic Systems(GZKF-202017)the Open Foundation of the National Engineering Technology Research Center for Prefabrication Construction in Civil Engineering(2021CPCCE-K02).
文摘Focusing on the ball double-screw hydraulic knee joint as the research object,this paper analyzes the load driving performance of the hydraulic knee joint.Taking the posture data of the human body such as walking,squatting and landing buffer as initial learning objects,motion features are extracted.By simplifying the trajectories of different motion actions into key feature control points and flexible trajectory fitting,the trajectory of joint actions is optimized.This method can realize the adaptability of the hydraulic robot knee joint in different movements,and take the flexible action as the optimization goal under the condition of ensuring the movement performance,so as to reduce the damage to the knee joint caused by the foot impact in motion.The simulation model was built by Adams and Matlab to complete the performance analysis and motion optimization experiment of the knee joint.The simulation results show that the foot impact force of the experimental model decreases gradually through optimization.Finally,the method is applied to the hydraulic joint experimental prototype to prove its load capacity and flexible motion control performance.
