Analysis And Compensation Of Guideway Errors For Turbine Special Repair Robot

As the scale of hydroelectric is growing in china,a large number of turbines need to repair,there are many problems when people repair turbine,such as small work space,heavy workload,poor environment and so on,traditional manual repair can not achieve the accuracy and efficiency of the turbine repair work.Although several scholars have developed several repair robots of the turbine in the pit,but there is an error between the advance accuracy and the actual accuracy,repair error seriously affected the efficiency of the turbine.Our team collaborate with Manwan Hydropower which is part of Yunnan Lancang River Hydropower Group,our aim is to seek the cause of errors when robot repair turbine and compensate error,this paper focuses on the error of turbine repair robot and how to compensate error.Firstly,this paper analyzes the kinematics of repair robot.It establishs positive and inverse kinematics models of the robot based on the D-H method,and use MATLAB to verify the correctness of the positive inverse kinematics model;it plans polished robot path,then imports motion parameters into the virtual repair robot.This paper simulates the process in ADAMS which repair robot is grinding,the simulation result is the basis of error analysis in the further.Secondly,this paper analyzes that the deformation of the flexible guide influences accuracy of repair robot.It researchs the flexible body modeling theory,and establishs error model of flexible guide,since the calculate volume and low efficiency when it uses numerical method to calculate error model,this paper uses rigid-flexible coupling method to analyze the robot end position accuracy which causes by the flexible guide,and specifically analyzes the error of robot which causes by different tool gravity and the thickness of flexible guide.Finally,this paper how to the repair robot end position error.It establishs a robot end position error model,and analyzes the robot pose compensation method,it writtens MATLAB control subroutine by perturbation error compensation method,robot end-effector trajectory tracking control is studied,and it writtens control subroutine control law based on the decomposition of the robotic arm,this paper also establishs joint control model by using MATLAB + ADAMS,it designes to verify the compensation controlling effect.This paper gains the following conclusions: the deformation of flexible rail causes position error of the turbine repair robot,the robot position errors is greater than befor when the greater force applys on end of the robot,while the thickness of the rail will also have an impact on the size of the position error of the robot,it can effectively reduce the repair robot position error and the time which the robot reaches a stable state by using perturbation error compensation method.