| As the key point of material seismic performance testing,structure vibration test has been widely used in civil engineering,automotive engineering ocean engineering and other practical engineering environment,which can provide experimental basis for the improvement of product structure design and technical innovation.Electro-hydraulic shaking table is the key equipment for material structural vibration test because of its fast response and small error.Sinusoidal vibration test is an essential part of structural vibration test,which can be commonly used to simulate periodic environment.Therefore,to achieve high-precision control of electro-hydraulic shaking table sinusoidal test has significant application value in engineering.However,in the actual sinusoidal test,the acceleration response always exists harmonics distortion under the combined influence of a variety of non-linear factors,which seriously decrease the effectiveness of the sinusoidal vibration test.At present,the commonly used targeted cancellation method can only compensate a certain nonlinear factor,and it is difficult to achieve the ideal control precision.In addition,there is still a big gap between the self-developed electro-hydraulic shaking table system in China and foreign countries.In the process of system architecture design and project implementation,there are still many practical problems to be solved,such as efficient communication between controllers,real-time analysis and processing of vibration test data.For this reason,the thesis focus on the adaptive nonlinear compensation control strategy of electro-hydraulic shaking table sinusoidal test,and the engineering design and implementation method of the electro-hydraulic shaking table system.The main work is as follows:1.Based on the detailed analysis of the working principle and non-linear characteristics of the electro-hydraulic shaking table,a three-variable control system model is build built by using MATLAB/Simulink,through simulation and actual sinusoidal test,the problem of harmonic distortion of acceleration response caused by non-linear factors in the electro-hydraulic shaking table is analyzed.To solve this problem,an adaptive amplitude-phase control algorithm and an adaptive harmonic cancellation algorithm are designed based on the Least-Mean-Square adaptive filter.The former is used to improve the fundamental frequency response;and the latter can decrease the harmonic noise in output waveform.The performance of the algorithm is tested by simulation2.Global design and engineering implementation of the electro-hydraulic shaking table control system are carried out:The thesis combines the Kalman harmonic estimation algorithm,TCP thread pool concurrent server and custom extensible application layer protocol to design and implement an Ethernet-based vibration platform software system,which integrates multiple functions such as user command processing,experiment monitoring and data analysis;The servo controller focuses on implementing basic servo control algorithms and adaptive non-linear compensation algorithms to achieve closed-loop control of the system.After software and hardware joint debugging,the above control system can meet the basic control requirements of the electro-hydraulic shaking table.3.Perform the algorithm debugging and sinusoidal test on the electro-hydraulic shaking table,and test the function of each part of the system.Through the comparative study of the time domain response and the harmonic identification result of the acceleration sinusoidal test,and the analysis of the weight adjustment process and the error change in the test,the validity and convergence of the algorithm are proofed.It can be seen from the experimental result:the adaptive non-linear compensation algorithm can significantly diminish the distortion of the response waveform from 26.32%to 12.65%after convergence,which meets the precision requirements of sinusoidal test in GB/T 21116-2007. |
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