This paper presents a new study on modeling and optimization of trajectory and posture for the super-giant(SG)slalom of alpine skiing.It is the first time that a Three-Rigid-Body-Particle model based on rigorous deriv...This paper presents a new study on modeling and optimization of trajectory and posture for the super-giant(SG)slalom of alpine skiing.It is the first time that a Three-Rigid-Body-Particle model based on rigorous derivations and stability analysis is established to represent skiers trajectory and posture characteristics,as it is more accurate than the single-rigid-body model which is commonly used in existing studies.In addition,the Radau pseudospectral method is applied to solve the trajectory and posture optimization problem in order to obtain better skiing trajectory,skiing posture,and some key kinematic parameters of skiers.Moreover,this paper analyzes the effects of different body types,minimum turning radii,and flexor and extensor strength of knees and hip joint on skiing performance.Finally,based on the findings of the study,some advice about how to improve the performance of the SG slalom in view of science and technology is given to skiers and coaches for reference.展开更多
This paper focuses on the stability analysis of the active disturbance rejection control (ADRC)for a class of uncertain systems.To overcome the difficulty of defining a reasonable Lyapunov function and setting limitat...This paper focuses on the stability analysis of the active disturbance rejection control (ADRC)for a class of uncertain systems.To overcome the difficulty of defining a reasonable Lyapunov function and setting limitations of system parameters,the converse Lyapunov theorem and the disturbance theory are employed.This paper proves that the estimation error of the extended state observer (ESO)and the tracking error of the closed-loop system using ADRC are uniformly ultimately bounded and monotonously diminishing with the increase of their respective bandwidth,so that the stability of the ADRC system could be performed.In order to further illustrate the relationship between the stability range and bandwidths,it analyzes quantitatively the performance of ESO and ADRC based on the root locus and the step response.Finally,an example based on a typical control system is carried out,and simulation results verify the theoretical analysis proved in this paper.展开更多
基金supported in part by the Key Technology Research and Demonstration of National Scientific Training Base Construction of China under Grant No.2018YFF0300800in part by the National Natural Science Foundation of China under Grant No.62173323in part by Beijing Institute of Technology Research Fund Program for Young Scholars.
文摘This paper presents a new study on modeling and optimization of trajectory and posture for the super-giant(SG)slalom of alpine skiing.It is the first time that a Three-Rigid-Body-Particle model based on rigorous derivations and stability analysis is established to represent skiers trajectory and posture characteristics,as it is more accurate than the single-rigid-body model which is commonly used in existing studies.In addition,the Radau pseudospectral method is applied to solve the trajectory and posture optimization problem in order to obtain better skiing trajectory,skiing posture,and some key kinematic parameters of skiers.Moreover,this paper analyzes the effects of different body types,minimum turning radii,and flexor and extensor strength of knees and hip joint on skiing performance.Finally,based on the findings of the study,some advice about how to improve the performance of the SG slalom in view of science and technology is given to skiers and coaches for reference.
基金supported by the National Natural Science Foundation of China under Grant No.61304026
文摘This paper focuses on the stability analysis of the active disturbance rejection control (ADRC)for a class of uncertain systems.To overcome the difficulty of defining a reasonable Lyapunov function and setting limitations of system parameters,the converse Lyapunov theorem and the disturbance theory are employed.This paper proves that the estimation error of the extended state observer (ESO)and the tracking error of the closed-loop system using ADRC are uniformly ultimately bounded and monotonously diminishing with the increase of their respective bandwidth,so that the stability of the ADRC system could be performed.In order to further illustrate the relationship between the stability range and bandwidths,it analyzes quantitatively the performance of ESO and ADRC based on the root locus and the step response.Finally,an example based on a typical control system is carried out,and simulation results verify the theoretical analysis proved in this paper.
