Quadruped robot dynamic gaits have much more advantages than static gaits on speed and efficiency, however high speed and efficiency calls for more complex mechanical structure and complicated control algorithm. It be...Quadruped robot dynamic gaits have much more advantages than static gaits on speed and efficiency, however high speed and efficiency calls for more complex mechanical structure and complicated control algorithm. It becomes even more challenging when the robot has more degrees of freedom.As a result, most of the present researches focused on simple robot, while the researches on dynamic gaits for complex robot with more degrees of freedom are relatively limited. The paper is focusing on the dynamic gaits control for complex robot with twenty degrees of freedom for the first time. Firstly, we build a relatively complete 3 D model for quadruped robot based on spring loaded inverted pendulum(SLIP) model, analyze the inverse kinematics of the model, plan the trajectory of the swing foot and analyze the hydraulic drive. Secondly, we promote the control algorithm of one-legged to the quadruped robot based on the virtual leg and plan the state variables of pace gait and bound gait. Lastly, we realize the above two kinds of dynamic gaits in ADAMS-MATLAB joint simulation platform which testify the validity of above method.展开更多
To the Editor:Anterior cruciate ligament(ACL)rupture is a frequent knee injury that modifies knee joint kinematics,including intra-articular motions and forces,leading to recurrent functional instability of the knee.W...To the Editor:Anterior cruciate ligament(ACL)rupture is a frequent knee injury that modifies knee joint kinematics,including intra-articular motions and forces,leading to recurrent functional instability of the knee.With an estimated 200,000 ACL ruptures annually in the United States,ACL ruptures are prevalent,especially in young,physically active individuals.[1]Restoring knee morphology,stability,and function is the aim of conventional therapy,which is ACL reconstruction(ACLR).[2]Previous studies have evaluated gait function at different time points before and after ACLR to quantify impairments in movement patterns and knee joint biomechanics.[3]These investigations have consistently revealed substantial alterations in gait patterns induced by ACLR,with recovery persisting for at least 6 months post-procedure.[4]Majewska et al[4]pointed out that most studies focus on short-term follow-up within 6 months after surgery,while time-dependent changes in long-term dynamic functional recovery remain poorly studied.Accordingly,we aimed to perform gait analysis both pre-ACLR and throughout the 12 months postoperatively,complemented by standard assessments of knee joint function.展开更多
Gait is the collective term for the two types of bipedal locomotion, walking and running. This paper is focused on walking. The analysis of human gait is of interest to many different disciplines, including biomecha- ...Gait is the collective term for the two types of bipedal locomotion, walking and running. This paper is focused on walking. The analysis of human gait is of interest to many different disciplines, including biomecha- nics, human-movement science, rehabilitation and medicine in general. Here we present a new model that is capable of reproducing the properties of walking, normal and pathological. The aim of this paper is to establish the biomechanical principles that underlie human walking by using Lagrange method. The constraint forces of Rayleigh dissipation function, through which to consider the effect on the tissues in the gait, are included. Depending on the value of the factor present in the Rayleigh dissipation function, both normal and pathological gait can be simulated. First of all, we apply it in the normal gait and then in the permanent hemiparetic gait. Anthropometric data of adult person are used by simulation, and it is possible to use anthropometric data for children but is necessary to consider existing table ofanthropometric data. Validation of these models includes simulations of passive dynamic gait that walk on level ground. The dynamic walking approach provides a new perspective of gait analysis, focusing on the kinematics and kinetics of gait. There have been studies and simulations to show normal human gait, but few of them have focused on abnormal, especially hemiparetie gait. Quantitative comparisons of the model predictions with gait measurements show that the model can reproduce the significant characteristics of normal gait.展开更多
基金supported by the National Science Fund for Distinguished Young Scholars of China(51225503)the National Natural Science Foundation of China(61603076)the Fundamental Research Funds for the Central Universities(ZYGX2016J116)
文摘Quadruped robot dynamic gaits have much more advantages than static gaits on speed and efficiency, however high speed and efficiency calls for more complex mechanical structure and complicated control algorithm. It becomes even more challenging when the robot has more degrees of freedom.As a result, most of the present researches focused on simple robot, while the researches on dynamic gaits for complex robot with more degrees of freedom are relatively limited. The paper is focusing on the dynamic gaits control for complex robot with twenty degrees of freedom for the first time. Firstly, we build a relatively complete 3 D model for quadruped robot based on spring loaded inverted pendulum(SLIP) model, analyze the inverse kinematics of the model, plan the trajectory of the swing foot and analyze the hydraulic drive. Secondly, we promote the control algorithm of one-legged to the quadruped robot based on the virtual leg and plan the state variables of pace gait and bound gait. Lastly, we realize the above two kinds of dynamic gaits in ADAMS-MATLAB joint simulation platform which testify the validity of above method.
基金supported by the National Key Research and Development Program of China(Grant No.2024YFC2510400)Key Research and development projects of Shanxi province(202202150401019)the Central Government Guides Local Science and Technology Development Funds(Grant No.YDZJSX2022B011).
文摘To the Editor:Anterior cruciate ligament(ACL)rupture is a frequent knee injury that modifies knee joint kinematics,including intra-articular motions and forces,leading to recurrent functional instability of the knee.With an estimated 200,000 ACL ruptures annually in the United States,ACL ruptures are prevalent,especially in young,physically active individuals.[1]Restoring knee morphology,stability,and function is the aim of conventional therapy,which is ACL reconstruction(ACLR).[2]Previous studies have evaluated gait function at different time points before and after ACLR to quantify impairments in movement patterns and knee joint biomechanics.[3]These investigations have consistently revealed substantial alterations in gait patterns induced by ACLR,with recovery persisting for at least 6 months post-procedure.[4]Majewska et al[4]pointed out that most studies focus on short-term follow-up within 6 months after surgery,while time-dependent changes in long-term dynamic functional recovery remain poorly studied.Accordingly,we aimed to perform gait analysis both pre-ACLR and throughout the 12 months postoperatively,complemented by standard assessments of knee joint function.
文摘Gait is the collective term for the two types of bipedal locomotion, walking and running. This paper is focused on walking. The analysis of human gait is of interest to many different disciplines, including biomecha- nics, human-movement science, rehabilitation and medicine in general. Here we present a new model that is capable of reproducing the properties of walking, normal and pathological. The aim of this paper is to establish the biomechanical principles that underlie human walking by using Lagrange method. The constraint forces of Rayleigh dissipation function, through which to consider the effect on the tissues in the gait, are included. Depending on the value of the factor present in the Rayleigh dissipation function, both normal and pathological gait can be simulated. First of all, we apply it in the normal gait and then in the permanent hemiparetic gait. Anthropometric data of adult person are used by simulation, and it is possible to use anthropometric data for children but is necessary to consider existing table ofanthropometric data. Validation of these models includes simulations of passive dynamic gait that walk on level ground. The dynamic walking approach provides a new perspective of gait analysis, focusing on the kinematics and kinetics of gait. There have been studies and simulations to show normal human gait, but few of them have focused on abnormal, especially hemiparetie gait. Quantitative comparisons of the model predictions with gait measurements show that the model can reproduce the significant characteristics of normal gait.
