Research On Static Instability Mechanism And Control Method Of Lower Limb Exoskeleton Robot

With the accelerated pace of agricultural modernization in our country in recent years,many regions due to various factors to large-scale popularization and realize mechanization,and in these areas especially for large-scale mechanized management does not have the conditions of economic crops,has low labor efficiency,labor intensity,long working time,the field management and harvesting process in the lower extremity workers fatigue easily etc..Therefore,if the harvest and field management application of robot technology in the field of agriculture,the corresponding lower extremity exoskeleton,can greatly reduce labor intensity,improve work efficiency,effectively prolong the working time,reduce the amount of labor,save manpower cost,create more economic value,thus speeding up the modernization of agriculture in our country the pace of.According to the characteristics of human gait motion,this paper presents a realization of lower extremity exoskeleton bionics joint exoskeleton,convenient wearing and flexible movement characteristics of the lower extremity exoskeleton mechanism,provides a new way for the field work of workers.In this paper,firstly,the research background,current situation and future development direction of the exoskeleton robot are introduced,and the research significance and purpose of the exoskeleton robot are expounded.The physiological characteristic,for lower limb gait characteristics,analysis of driving mode and dynamics of human freedom,kinematics analysis,single support period,the design of a lower extremity exoskeleton mechanism,hip,knee,ankle and foot and other main parts for this mechanism explains the detailed design,and so on the mechanism of freedom analysis.Then introduce the basic knowledge spiral theory and its basic definition,singularity,and on this basis,the design of institutions,to establish the static equilibrium equations to simplify mechanism model of Jacobian matrix to calculate the singularity of the analysis of the instantaneous motion,and the launch of its instability condition and the singularity position.Then,based on the definition of FZMP and support polygon,the definition ofworkspace and the basic knowledge of optimization method,the position of support polygon is determined,and then the static position is determined according to the rotation boundary.And take this as an active control strategy to restore stability to meet the requirements of maintaining stability.Then,based on the maximum workspace area as the objective function,the area function of its moving space is established based on the constraint conditions,and the optimization is taken as the objective function.Then the maximum workspace area of the workspace is solved by using MATLAB,and the maximum working range of the motion is obtained.Finally,by setting two groups of exoskeleton motion simulation of the starting point,this design work space by MATLAB,through the boundary search method to determine the workspace boundary and area,finally gives the joint angle and the length of the motor change value,proved the feasibility and method of loss control strategy of stability judgment.It provides the theoretical basis and technical support for the research of the exoskeleton control system of the lower limb.