Resaerch On Design And Control Of Modularized Flexible Joint For Service Robot

With the rapid development of social production and lifestyle develops,and the intensifying aging population,the demand for service robots increased year by year.In the process of using service robots,when the relationship of man and machine became man-machine collaboration,the primary problem is the safety of human being.Elastic actuator has the characteristics of security interaction,impact resistant,and it is applied to the service robot joint structure can improve the security of human-machine collaborative process.This work designs a modular elastic actuator corresponding control research.Firstly,The flexible joint frequency domain characteristics analysis.Establish a simplified model of the flexible joint.Under frequency domain,we analyze the influence of different driving source on the joint system stability,the output bandwidth,the amplitude frequency and the phase following features.And the influence of different parameters,such as stiffness and damping,on the joint system.In the force source drive model,we analyze the output impedance and impact resistance of the flexible joint.Secondly,we formulate the technical indexes of the joint.According to the actual application situation of the flexible joint,developing technical indexes of the flexible joint.Based on those indexes,we designed the flexible joint in detail,including its structure,working principle and control system.Using size optimization designed it based on the finite element method by the simulation software to verify the rationality of the design of the elastic element.Thirdly,the flexible joint dynamics modeling and simulation control.Under the force source model,we construct the accurate dynamics model of the flexible joint,in which the influence of joint friction and outside moment.According to the dynamic model,two kinds of position control algorithm,PD control based on gravity compensation and PD control based on fuzzy control were designed.We analysis the position holding performance of the flexible joint and the effect of the position following algorithm by simulation.In order to make the flexible joint have the characteristics of flexibility,security,also designed two kinds of impedance controller which respectively based on the impedance of the gravity compensation controller and adaptive impedance controller based on forgetting factor.The flexible joint with inner ring for position control of impedance control,through simulation analysis of the flexible joint stiffness change of environment and contact force,and position of different impedance controller with sex,anti-jamming and environmental adaptability,verify the validity of the impedance controller.Finally,a modular flexible joint experiment platform is established.We conducted experiments of safety impact and position control to verify the validity of the position control algorithm and the security of the flexible joint.