Research On Displacement Response Reconstruction And Machinery Error Processing

In the engineering research, dynamic responses of structural systems are frequently measured for the purpose of structural health monitoring and structural control. Among the dynamic responses, the time history of the dynamic displacement may contain important information on structural behaviors. For example, in case a structure experiences severe events such as a strong earthquake or a typhoon, a quick decision on the possibility of structural damage could be made based on the maximum displacement of the structure. For structural control applications, information on displacement should be provided in real-time or at least in near real-time to identify the states of a structure. Unfortunately, it is very difficult to measure displacement directly in large-scale structures because fixed reference points are rarely found to install displacement transducers. Moreover, the reference points as well as a structure move together during severe events, and thus the direct measurement of displacement using contact displacement transducers becomes almost impossible.Unlike displacement, acceleration is easily measured without a fixed reference point, and various types of accelerometers are commercially available for a wide range of dynamic frequencies. From this perspective, the reconstruction of displacement from measured acceleration seems to be a better method than the direct displacement measurement.This paper presents a new displacement reconstruction scheme based on the discrete singular convolution finite impulse response (DSC-FIR) filter. In this study, the governing equation and transfer function of the exact and an inverse problem is derived and the selecting of filter size, the features of the DSC-FIR filter on different filter size are presented. Finally, simulation and experiment are implemented to verify the proposed displacement reconstruction scheme and the results indicate that the scheme not only can accurately reconstruct displacement from the measured acceleration, but also has the ability for noise suppression.In mechanical engineering, the processing and installation error will affect the machinery’s mechanical properties and even may cause devastating damage. Therefore, we need to study the treatment for these errors in order to maximum decrease the impact of these errors on mechanical properties of the device.For possible resonance caused by the processing and installation error, we propose a robust design idea that considers the influence of these error on mechanical properties in the design or re-design stage. With the robust design, the mechanical products possess strong robustness. Using this design idea, we successfully optimize the steering wheel idle vibration of the forklift truck. For planar linkage mechanisms with the same parts, we propose a minimum sum of displacement variance(MSDV) method to find the optimal combination and minimize the influence of processing error on planar linkage mechanisms. For an eight-link linkage mechanisms, we use the MSDV method to obtain the optimal combination and simulation result indicate that the proposed method can effectively reduces the influence of machining error.