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The forecast of machine performance has been widely discussed in recent years, where accurate predictions with common regularity could reduce costs and achieve time-efficient construction. This study uses the case of predicting the load (including the thrust and torque) acting on tunneling machine. Because most data-mining techniques are black-box models, which rely too much on specific data and cannot...
In order to improve the starting torque of the soft start of the asynchronous motor and reduce the starting current, a soft starting method from the second frequency to the power frequency starting is proposed. On the basis of this theory, the simulation model of soft start system of asynchronous motor graded frequency conversion control is built by Simulink simulation function of MATLAB. The simulation...
Aiming at the starting problem of motor equipment, this paper studied a large of existing soft start modes and their starting characteristics. Then, using MATLAB/Simulink tool to build common soft start simulation models, this paper got a lot of simulation waveforms. These helped to identify the applicable occasions of these soft starters and their respective advantages and disadvantages. We designed...
The technology of rotation modulation is applied on four-gimbal platform can improve the accuracy system and overcome the shortages of the strapdown system which cannot isolate the carrier angle motion. In this paper, a new design method of dual-axis rotation control system on four-gimbal platform is proposed. The performance index is demonstrated by analysis the influence of the rotation control...
An energy exchange relation of the permanent magnet synchronous motor control system is analyzed firstly. Then a novel control strategy using the rotor kinetic energy is proposed. A load estimation method is put forward for the load and inertia ripple. The simulation and experiment results demonstrate the effectiveness of the proposed control strategy and the method.
In order to achieve large tolerance capture and high stiffness connection for space payload operations, a Chinese large-scale space end-effector (EER) was developed. Friction is a kind of strong nonlinear factor that severely degrades performance of EER. To predict the friction amplitude and compensate the dynamic error, the friction model based Generalized Maxwell-Slip model (GMS) is built. In order...
The load identification of the shield machine is presented in this paper by introducing the mechanical analysis of shield excavating into the nonlinear multiple regression of on-site data. The analysis on mechanical characteristics of shield-soil system can decouple the nonlinear multi-parameter problem of load, so it is great helpful for the regression process to establish a load model. Then a load...
This paper studied the method of the wind turbine's dynamic modeling creation based on the research of the relationship between the blade attack angle of the new vertical wind turbine and its efficiency, and also studied the fuzzy neural network algorithm based on BP network which was applied in the constant speed control of such a new vertical wind turbine. We created a specific mathematical model...
This paper presents a mechanical model to predict the operational loads acting on the cutter head of shield tunnel machine during excavation based on contact mechanics theory, in which the cutter head is considered as a rigid cylinder punch and the soil to be excavated is simplified as an elastic half-space. Then the estimation formulae of the operational loads are obtained and the influence of some...
The motion characteristics of 300T high-speed presses are obtained by kinematic analysis and dynamical analysis of main movement mechanism which according to its operating features and the basic principle of mechanical design. Equivalent moment of resistance force is also obtained by equivalent force analysis of mechanism based on the basic equation of machine movement. The results of this study provides...
The brushless doubly fed machines (BDFM) have been widely researched. The BDFM system has lots of advantages such as brushless, simplicity, robustness and reliability, and a much smaller power electronic converter compared to a conventional AC induction machine. The BDFM as a new type of AC machine and is attractive for converter-fed variable speed drive applications and variable-speed constant-frequency...
A brushless DC motor (BLDCM) state equations based on speed error are established in this paper, and a sliding mode controller with a variable structure based on exponential reaching law is designed for speed regulation of BLDCM. Kalman Filter is used to improve the performance in the situation of noise disturbance. The control performances of variable-structure controller presented in this paper...
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