| The vibration of industrial robot will reduce its fatigue life and affect its working efficiency.For a long time,researchers have been devoted to reducing the vibration of robots and improving the dynamic performance of robots.To solve these problems,this research group extended the "multi-degree-of-freedom controllable mechanism" to the field of robot mechanism,and proposed a new type of controllable mechanism robot mechanism.In order to study the dynamic performance of this kind of robot mechanism and avoid its abnormal vibration,this paper takes a developed robot mechanism as the research object,and conducts an in-depth study on its dynamic performance and vibration characteristics.The main contents include:In this paper,the configuration of the new controllable robot mechanism is analyzed,and the degree of freedom of the robot mechanism is calculated.Based on this,the kinematics model is established,and its forward and inverse kinematics are analyzed,and workspace of the robot mechanism are studied.Through an example,the results of numerical simulation and software simulation are compared,and the correctness of the kinematics model is verified.The rigid body dynamics model of the new controllable robot mechanism is established by Lagrange method,and the driving torque is calculated.The influence of the section parameters of the big arm and the small arm on the driving torque is discussed with an example.The results show that the peak value of driving torque increases with the increase of rod thickness and rod width.Based on the finite element method,the elastodynamic model of the new controllable robot mechanism is established,and its frequency characteristics are analyzed.The natural frequencies of the system are calculated:the range of the first natural frequency is between 13-15.5 Hz,and the range of the second natural frequency is between 22-27 Hz.The influence of the bar section parameters on the natural frequencies is also explored.Finally,modal experiments are carried out to verify the elastodynamic model of the system.The vibration characteristics of the new controllable robot mechanism are studied.The dynamic equations are decoupled,and the vibration mechanism of the mechanism system under the action of self-excited inertial force is studied by using multi-scale method,and the conditions of nonlinear resonance are analyzed:when the angular velocity of the driving motor is close to the r-th natural circle frequency of the mechanism system,the main resonance will occur;When the angular velocity of two driving motors is correlated with the natural circle frequency of the system,i.e.|±?1±?2|??r,the combined resonance will occur. |
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