Research On Control Technology Of Random Vibration Test System For Transport Package

The vibration excitation caused by uneven roads are one of the main factors that cause damage to packages and their built-in goods during long-distance transportation.The random vibration test simulates the vibration environment that the packages are subjected to during the actual transportation through the vibration table system,which is an important means to verify the reliability of the package and optimize its design.The scientific and effective random vibration test system and control technology for transport packages are of great significance to optimize the structural design of package and improve product reliability.In this thesis,a hardware platform suitable for random vibration test is designed according to the random vibration test requirements for transport packages.For the traditional test control technology cannot replicate power spectrum density accurately and the super-Gaussian vibration environment cannot be simulated effectively.The control technology in the random vibration test of transport packages is focused on and the improved control technology is proposed.A software application platform is designed and the effectiveness of the vibration test system and control technology are verified.The main tasks include:Firstly,a hardware platform of random vibration test is designed according to the theory of random vibration test and the related national standards for transport package,which uses the industrial computer as the core controller and the electromagnetic vibration table as the actuator.Secondly,the control technology of random vibration test is focused on.The power spectral density estimation,generation of time-domain drive signals,and iterative correction of the drive spectrum are studied in the power spectral density replication technique.Aiming at the problem that the iterative correction of driving spectrum has poor effect on the power spectral density replication,a least mean square adaptive driving power spectrum correction method is proposed.Simulations verify that the adaptive driving power spectrum correction method can quickly and accurately replicate the target power spectral density.In addition,aiming at the problem that the Gaussian time domain driving signal generated in the traditional random vibration test technology can not accurately simulate the actual super-Gaussian random vibration environment,the generation technology of the super-Gaussian random vibration test driving signal is proposed,and the super-Gauss signal generated by simulation is analyzed.Finally,a software system of random vibration test for transport packages is designed based on LabVIEW and to verify the effectiveness of the optimized control technology.The actual vibration test shows that the adaptive correction improves the accuracy and stability of the power spectral density replication process effectively.The driving signal generated by the super-Gaussian random vibration control algorithm has a typical super-Gaussian characteristic,with response power spectral density meeting the tolerance requirement of ±3dB,and the response kurtosis error is controlled within ±7%,which meets the testing requirements in line with actual random vibration environment.