| The purpose of meeting the demands of urban housing supply and demand,the number and height of high-rise and super high-rise buildings have been updated.Elevator as a vertical means of transportation in high-rise buildings,its speed gradually increases.With the continuous improvement of the elevator running speed,a series of vibration problems will occur,which will not only damage the measurement accuracy of precision instruments in the elevator,reduce the operation safety of the elevator,but also lead to safety accidents such as inaccurate flat floor position of the elevator;at the same time,vibration and mechanical noise will cause adverse physiological reactions such as dizziness and tinnitus of passengers,which will seriously affect the comfort of the elevator.Therefore,the design of active vibration reduction control strategy which is closer to the actual environment of the elevator to ensure that passengers get superior ride comfort experience has become one of the key problems to be solved in the research and development of high-end elevator products.In order to solve the problem that the different vibration responses of the car body and the car frame are caused by the inconsistency of the mass center position in the real environment,the mass spring damping method is used to linearize the actual model of the car system.At the same time,the electro-hydraulic active guide shoe model is designed for the car system,and the4-DOF horizontal vibration active control model of high-speed elevator car system is constructed based on Lagrange energy method.The Gauss white noise after low-pass filtering is used as the excitation input of the guide rail of the car system,and the acceleration time-frequency response of the horizontal vibration dynamic model of the car is simulated by MATLAB.Furthermore,with the help of the cooperative company's 120m high-speed elevator test tower,a 4m/s high-speed elevator test platform was built to obtain the measured acceleration response of the car in the real operating environment,and the typical digital characteristics of the acceleration response after the numerical simulation were compared and analyzed to verify the correctness of the dynamic model,which laid the foundation for the following research on the active vibration reduction control strategy of the car system model basis.Considering the influence of friction,wearing and spring aging of rolling guide shoe on car system,a robust control strategy for active vibration reduction of car system with uncertain parameters is designed.Based on the 4-DOF dynamic model of the car system,the linear fractional transformation(LFT)method is utilized to construct the state space equation of the car system with parameter uncertainty.Secondly,the horizontal acceleration at the center of the car floor is taken as the controlled performance index,the vibration displacement at the upper and lower position of car frame,as well as output control force of the actuator are taken as the mechanical constraint index.The robust guaranteed cost state feedback controller is designed based on linear matrix inequality(LMI)convex optimization method.Further,a free matrix is introduced to reduce the conservatism of the proposed controller.Hence,the numerical simulation of the car system under three conditions of parameter uncertainty is carried out to verify that the proposed controller in this thesis can ensure that the car system has better vibration suppression ability and good robustness.An H_?output feedback controller with adaptive gain is proposed to effectively improve the poor adaptive ability of the traditional robust controller.Aiming at the uncertainty of mass and moment inertia of the high-speed elevator car,the horizontal vibration state space equation of nonlinear uncertain car system is constructed by T-S fuzzy reasoning approach.Based on the controlled performance index of the horizontal vibration acceleration of the car floor and the control force of the actuator,the dynamic feedback control law with adaptive gain is designed by utilizing LMI convex optimization method and parallel distributed compensation(PDC)rule with the horizontal vibration acceleration of the car frame as the controlled performance index and the vibration displacement at the center of mass of the car frame as the output index,which to obtain smaller vibration acceleration peak.The effectiveness and robustness of the controller are verified by the numerical simulation of 4m/s high-speed elevator car system under no-load and heavy load conditions,which can provide theoretical guidance for the research and development of high-speed elevator active shock absorber in engineering practice.Considering the problem that the input delay of existing hydraulic actuators affects the control performance of the system due to the viscosity of the oil,and that the human body is more sensitive to the horizontal vibration amplitude of the car in the frequency range of 1-2HZ,a finite frequency H_?robust control strategy with actuator delay is proposed to achieve the active vibration reduction of the car in the sensitive frequency range of the human body.Founded on the 4-DOF dynamic model of the car system,the state space equation of the car system with input delay is constructed.Taking the above performance index of robust controller design,combined with generalized KYP lemma and LMI method,the finite frequency H_?robust controller is designed.Furthermore,the vibration acceleration time-frequency characteristic curves of the car body and the car frame under random excitation and pulse excitation are compared and analyzed under the condition of maximum time delay.It is verified that the vibration amplitude of car system under the designed controller is reduced more greatly,and the convergence speed is faster under the pulse excitation. |
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