No abstract

The precise inspection of geometric parameters is crucial for quality control in the context of Industry 4.0. The current technique of precise inspection depends on the operation of professional personnel, and the measuring accuracy is restricted by the proficiency of operators. To solve the defects, this paper proposes a precise inspection framework for the geometric parameters of polyvinyl chloride (PVC) pipe section (G-PVC), using low-cost visual sensors and high-precision computer vision algorithms. Firstly, a robust imaging system was built to acquire images of a PVC pipe section under irregular illumination changes. Next, an engineering semantic model was established to calculate G-PVC like inner diameter, outer diameter, wall thickness, and roundness. After that, a region-of-interest (ROI) extraction algorithm was combined with an improved edge operator to obtain the coordinates of measured points on PVC end-face image in a stable and precise manner. Finally, our framework was proved highly precise and robust through experiments.

Appearance defect inspection is crucial for quality control in the context of Industry 4.0. This research introduces a joint surface defect inspection and classification framework for polyvinyl chloride (PVC) pipe based on the low-cost visual sensors and high-efficiency computer vision algorithms. First, we build a robust imaging system to acquire the surface of PVC (S-PVC) by considering its characteristics and the illumination condition into the modeling process. Second, we adopt the region of interest method to eliminate the background interference captured in the S-PVC imaging and design an efficient S-PVC defect inspection and classification method. Third, we build an automatic machine prototype to evaluate the efficiency of the proposed method. Experimental results demonstrate that our framework has the advantages of low latency, high precision, and robustness.

In this work, the seamlessly switch systems between shore electricity and ship electricity of dual frequency mode (50Hz-60Hz and 50Hz-50Hz) is proposed. It is mainly used in the power supply of ships (Abbreviated as SEG) which stay in the port, and the problem that the grid needs to be disconnected when the ship is provided with electricity from the shore electricity is resolved. Firstly, the phase locked loop (Abbreviated as PLL) control model is established in seamlessly switch systems between shore electricity and ship electricity of dual frequency mode. Secondly, the V/f control model of seamlessly switch system is established, and the frequency (f) follow is implemented in seamlessly switch systems combined with the phase locked loop control model. At last, the P/Q control model of seamlessly switch systems is proposed. The load power is transferred from the ship's generator to the shore electricity grid combined with phase locked loop control model. The power supply between the shore electricity which is 50Hz and the ship electricity which is 50Hz or 60Hz is achieved according to the grid technology research. Keywords: the seamlessly switch system; shore electricity; ship electricity; dual frequency mode; the phase -locked loop control model; the V/f control model; the P/Q control model.