Advanced Materials Research Vol. 1022

Abstract: The paper studies the effect of networks with transmission delay in the feedback loop of a nonlinear networked control system (NCS). The nonlinear system is modeled by a T-S fuzzy model, and transmission delays are modeled by a finite state Markov process. The fuzzy controller’s membership functions can be different from the plant’s. The membership functions of the plant and the fuzzy controller are incorporated into the controller design. System performance is measured via an norm from disturbance to error and the controller is computed by sum of square approach. Finally we applied these results to an inverted pendulum system. Theoretical analysis and simulation results show that the control strategy studied in this paper is effective and feasible.

Abstract: With application in turning, this paper presents a stability control system which based on a new strategy. It works by permanent assessment of the operating point position system which is relative to the stability limit and process parameter, in-process modification. For example, this point is always placed in the stable domain that gives the highest process performance. In the case of turning, here approached: first, this area is the stability limit proximity; second, the operating point system position is determined by assessing a cutting force monitored signal feature, last, it changed this position by modifying the cutting edge setting angle, the feed rate, and the cutting speed, as it follows: when the risk of the stability limit is imminent, the setting angle is increased, which followed by a feed rate diminishing and then by a worked piece rotation speed reduction, after surpassing the risk, the three variables modification is reversed, through this way the chatter onset could be avoided and the performance can be kept in every moment at the highest level. The system was experimentally implemented on a transversal lathe. The results of tests about dedicatedly designed specimens are showing a machining productivity that significantly increases, in conditions of a stable cutting process. Without important modifications, it can be easily added to the existing CNC machine tools.

Abstract: This paper studies the calculation model of the power frequency electric field surrounding the high voltage transmission line, and establishes the analysis model of the ball type sensor for measuring the alternating electric field. The distortion and the measurement error of the electric field caused by the sensor are discussed in the paper. For the 35KV transmission line, the paper compare the electric field (with the sensor in) with the electric field (with no sensor) by simulation, and achieve the conclusion that putting the ball type sensor into the electric field can cause the distortion, and the value of the distortion increases with the increase of the height, which leads to the increase of relative error.