Jia Deli

Decoupling control based on PID neural network for plasma cutting system

A decoupling control based on PID (proportional-integral-derivative) neural network and relevant algorithms are proposed in this paper. They are introduced to solve problems of nonlinearity and strong coupling between cutting speed and torchpsilas height in plasma cutting system. The dynamic model of system was established with use of BP (back-propagation) neural network. The actual experimental cutting result shows that decoupling control technology based on PID neural network is an effective decoupling control for cutting speed and torchpsilas height in plasma cutting system.

On fuzzy-PI control for inverted plasma cutting power supply

A fuzzy-PI double-mode controller is proposed in this paper. A variable interval fuzzy quantification algorithm with self-adjustable factor in full domain is also introduced in this paper. The controller combines PI control with this algorithm to study the inverted plasma cutting power supply and its strong nonlinearity and uncertainty in cutting process. This algorithm avoids complex nonlinear system modeling and adopts double-mode control to combine advantages of fuzzy control and PI control under. The optimized fuzzy control improves steady-state precision and dynamic performance of system, either of which the conventional algorithm can realize simultaneously. The simulation result shows that controller proposed in this paper enhances robustness and steady-state performance compared to PI controller or fuzzy controller.

The research of acoustic propagation characteristics in the periodic oil pipes

This paper was based on the acoustic propagation mechanism in the oil pipe, the transmission model is established, dispersion equation and spectral distribution equation are derived, and the attenuation characteristics of acoustic propagation is analyzed. The simulation experiments show when the acoustic propagation process in the periodic oil pipe, the spectrogram appears to be the periodic comb filter structure, meanwhile the overall frequency distribution presents center symmetrical rule. The results show that the calculating method can simulate the acoustic propagation in the periodic oil pipe efficiently. It provides a theoretical basis and criterion on how to identify and analyze the carrier frequency of acoustic data propagation technology in the oil pipe.

The CAD/CAM System of FRP Pipes

The CAD/CAM system of FRP pipes based on Internet is an integrated manufacturing system, used to design and produce high-pressure and sand-filling FRP pipes. It has realized the integration of the whole production process, from choosing of raw materials to winding machine control. The network of the system adopts the client/server mode, and the software is developed under VC++ 6.0 environment based on Windows 2000. The function and realization of process design, structure design and winding pattern design of CAD software are introduced. The winding pattern and speed control models are built according to fibre winding theory, and the open-architecture CAM system is designed based on industrial computer and motion controller. Key technologies such as CAM system software design, accurate timing in Windows and signal processing of rotary encoder are introduced. Practices show that this system shortens the development period of FRP pipes, and improves efficiency of production and management greatly.