Study On Disturbance Rejection Control Of Flexible End Grinding Force Of Wind Turbine Blade Grinding Robot

The widespread popularity of global wind power means that a considerable part of the blades enters the maintenance period.At the same time,more new blades are in short supply.The blade is one of the important components of the wind generator.It affects the efficiency of wind power generation.The manufacture and maintenance of wind turbine blades is extremely complex.As an important process in the manufacturing and maintenance process,blade is widely used in artificial grinding,but it has the disadvantages such as difficult to ensure the quality of grinding,low efficiency,and poor working environment.Therefore,the automated manufacture and repair of wind turbine blades has received increasing attention.Aiming at the characteristics and requirements of wind turbine blade grinding,a terminal flexible device similar SEA(series elastic actuator)that like human muscles was designed to adapt blade grinding force and curvature variety.The similar SEA dynamic model based on position source control and force source control was compared using frequency domain analysis.The analysis results showed that the dynamic model established by force source control had better stability and greater force output bandwidth.Therefore,the force source control method was used to establish the dynamic model.According to the Newtonian Euler equation,the dynamic model of the simillar SEA end grinding device based on the force source control was performed.The dynamic model adopts the state space expression.The auto disturbance rejection control replaced the fal function in the extended state observer expression with the arsh function and performed a simulation experiment.The experiment results showed that the arsh function extended state observer had good differential peak suppression ability and avoided the control larger input.Then,according to the dynamic model,the force controller was designed using auto disturbance rejection control and the simulation experiment was carried out with MATLAB/simulink.The experiment results showed that the auto disturbance rejection control can achieve better force control,and the parameters variety and external disturbances had a certain ability to suppress.A multi degree power law approach and a new type of nonlinear sliding surface were proposed,and their approaching time was compared theoretically.According to the dynamic model established,a nonsingular terminal sliding mode control was used to design a force controller and a simulation experiment was conducted.The simulation results showed that the nonsingular terminal sliding mode control can achieve a good tracking of grinding force,was insensitive to changes in parameters and disturbances,and had good robustness.Then using MATLAB and ADAMS co-simulation to compare the auto disturbance rejection control and nonsingular terminal sliding mode control,simulation results showed that the nonsingular terminal sliding mode control had a stronger ability to overcome the external disturbances,and better dynamic performance.