Based on the basic principle of Time-Of-Flight cameras,a novel MATLAB/SIMULINK model is proposed to measure phase delay of a modulated light signal which represents the distance from camera to object. Subsequently,by ...Based on the basic principle of Time-Of-Flight cameras,a novel MATLAB/SIMULINK model is proposed to measure phase delay of a modulated light signal which represents the distance from camera to object. Subsequently,by discussing influence factors of phase measurement,it is found that the integration time,the sampling time,and the aliasing effect have important effect on improving the accuracy of phase measurement. Interestingly,by analyzing different integration time and sampling time, it is found that the best integration time and sampling time are 0.05 ms and 10 ns,respectively. In this case(i.e.,in absence of the aliasing effect),the variation range of the distance error is between 1 mm and 11 mm in the interval of one period. Especially,under the consideration of the aliasing effect,the average value of distance error is half of that in absence of the aliasing effect. This improves the accuracy of the distance measurement greatly.展开更多
Double-sided weld pool shapes were determined by multiple welding parameters and wire feed parameters during pulsed GTAW with wire filler. Aiming at such a system with multiple inputs and outputs, an effective modelin...Double-sided weld pool shapes were determined by multiple welding parameters and wire feed parameters during pulsed GTAW with wire filler. Aiming at such a system with multiple inputs and outputs, an effective modeling method, consisting of the impulse signal design, model structure and parameter identification and verification, was developed based on MATLAB software. Then, dynamic neural network models, TDNNM (Topside dynamic neural network model) and BHDNNM (Backside width and topside height dynamic neural network model), were established to predict double-sided shape parameters of the weld pool. The characteristic relationship of the welding process was simulated and analyzed with the models.展开更多
基金National Natural Science Foundation of China(6127404361233010)Hunan Provincial Natural Science Fund for Distinguished Young Scholars(2015JJ1014)
文摘Based on the basic principle of Time-Of-Flight cameras,a novel MATLAB/SIMULINK model is proposed to measure phase delay of a modulated light signal which represents the distance from camera to object. Subsequently,by discussing influence factors of phase measurement,it is found that the integration time,the sampling time,and the aliasing effect have important effect on improving the accuracy of phase measurement. Interestingly,by analyzing different integration time and sampling time, it is found that the best integration time and sampling time are 0.05 ms and 10 ns,respectively. In this case(i.e.,in absence of the aliasing effect),the variation range of the distance error is between 1 mm and 11 mm in the interval of one period. Especially,under the consideration of the aliasing effect,the average value of distance error is half of that in absence of the aliasing effect. This improves the accuracy of the distance measurement greatly.
文摘Double-sided weld pool shapes were determined by multiple welding parameters and wire feed parameters during pulsed GTAW with wire filler. Aiming at such a system with multiple inputs and outputs, an effective modeling method, consisting of the impulse signal design, model structure and parameter identification and verification, was developed based on MATLAB software. Then, dynamic neural network models, TDNNM (Topside dynamic neural network model) and BHDNNM (Backside width and topside height dynamic neural network model), were established to predict double-sided shape parameters of the weld pool. The characteristic relationship of the welding process was simulated and analyzed with the models.
