Kinematic Reliability Study Of Folding Arm Mechanism For Construction Robot

Urbanization around the world continues to stimulate the development of the construction industry,and construction robots are widely used in the construction industry due to their high efficiency,high quality and accuracy,and high worker safety factor.According to the actual needs and working conditions of the construction industry,the construction robots are required to have high precision,repeatability and good stability.This thesis takes the construction robot folding arm mechanism as the research object,and introduces the concept of kinematic reliability into the study of motion accuracy of the folding arm mechanism in response to the problem that the traditional research method of motion error is not applicable to the error analysis of uncertainty factors.The paper analyzes the single-point kinematic reliability and timedependent kinematic reliability of the folding arm mechanism based on the mechanism kinematics research and error modeling.The main research contents of the thesis are as follows.1.An overview of the current development of China’s construction industry and the current situation in the field of construction robotics is presented.The structural characteristics of the new construction robots designed and manufactured are introduced.The current status and categories of mechanism kinematic reliability research are summarized.2.Analysis of the accuracy failure form of the folding arm mechanism.Kinematic analysis of the folding arm mechanism according to its structural characteristics.The forward and inverse solution equations of the folding arm mechanism are derived and validated and calculated.After that,the original error of the folding arm mechanism is analyzed,and the kinematic error model of the folding arm mechanism is established based on the differential method.3.Based on the kinematic analysis and error modeling of the folding arm mechanism,the effect of each original error variable of the mechanism on the motion accuracy of the end-effector is studied by introducing the concept of kinematic reliability.The single-point kinematic reliability model of the mechanism is established.Considering the influence of each hydraulic cylinder length dimension error,the primary second-order moment method is selected to analyze the mechanism singlepoint kinematic reliability.4.Based on the single-point kinematic reliability analysis of the mechanism,the time-dependent kinematic reliability model of the mechanism is established.The envelope is established to simulate the motion error of the mechanism.The timedependent kinematic reliability of the folding arm mechanism is analyzed by the envelope method.5.To verify the accuracy of the above fast solution strategy of kinematic reliability.The virtual prototype model of the folding arm mechanism is established in ADAMS.Based on the Monte Carlo method,the kinematic reliability of the folding arm mechanism is solved.By comparing the results,the effectiveness and accuracy of the method and route of this paper are proved.