Master-Slave Synchronous Control Method for Attenuating Dual Mode Electromechanical Transmission System Torsional Vibration

The high-power electromechanical transmission(EMT) system is a typical dual-mode hybrid power transmission system. The torque fluctuation of internal combustion engine causes serious shock and vibration problems of EMT. It is an important way to improve the life and smoothness of EMT system by using high dynamic regulation of motor torque to suppress the torsional resonance amplitude. Firstly, a lumped parameter rotational dynamic model of multi degree of freedom EMT system is established, and the inherent torsional vibration characteristics and dynamic coupling mechanism of the system are analyzed. Secondly, based on the synchronous response of the two motors in the open-loop state, a master-slave coupling EMT torsional active control strategy is proposed, and a speed feedback proportional differential control algorithm is designed. Then, the influence of control parameters, including lever coefficient Kab, proportional coefficient Kp and differential coefficient Kd, on the vibration characteristics of the system is analyzed. Finally, the calculation is carried out in the frequency domain and compared with the optimal modal control algorithm. The results show that the lever coefficient Kab and differential coefficient Kd of master-slave control can change the natural frequency of torsional vibration of the system, thus significantly changing the vibration response of the system. Selecting appropriate control parameters can achieve peak clipping of EMT torsional resonance amplitude, which is also of great significance to improve the NVH performance of the system.

Research on Speech Recognition System with Speaker Identification Based on the Cloud Server

The speech recognition system is not real-time, a speak identification method based on the cloud server is proposed to solve this problem. Firstly, the MFCC frequency cepstrum coefficient and the first order differential coefficient are extracted from the speech feature vector sequence to form 32 dimensional. And then the 32 dimensional speech feature vector is sent to the cloud server, the training speaker model and identification are done in the cloud server. Finally, the identification result is sent to the client.

Systems Errors Identification Method of Hull Deformation Data Based on Total Variation Constrained

Based on the analysis of influence factors for hull deformation data, physical models including hull curve deformation, hull torsion deformation and hull athletics deformation were established according to mechanical principle. Considering characteristics of the space instrumentation ship, systems errors identification method based on total variation constrained was provided. First order differential coefficient of deformation data was joined in a constrained equation in the method. Systems errors coefficient and exact value of deformation data were solved through alternating iterations. The simulation result of deformation measured data indicated that identification errors were in consistent with plus errors, and systems errors coefficient was also estimated accurately. This demonstrated that the proposed method is suitable for systems errors identification of hull deformation data.

Research of Hydraulic Cylinders Dynamic Characteristic and Synchrocontrol on Horizontal Pipes Connector in Deep Sea

The electro-hydraulic position-servo synchronization system of horizontal pipes connector was designed in order to connect two pipes in deep sea and make sure the journey of synchronization hydro-cylinders in the hydraulic system is less than 2 mm.Its transfer function of symmetric servo controlling oil-cylinder electro-hydraulic servo system were derived . Simulation analysis of its dynamic characteristic was done, and PID controller was applied on the system to regulate two hydraulic cylinder synchronization controls. In the end ,when the proportionality coefficient is Kp=0.55,integral coefficient is Ki=60,differential coefficient is Kd=0,the error of synchronic displacement was less than 0.5 mm, that achieved the request of the control system.

A DNA-PID Controller for an Industry Robot

In this paper, a DNA-PID controller is proposed for a 6-DOF robot. The experimental robot system has firstly been setup. Then the PID controllers of the robot joints are designed. Due to DNA algorithm’s excellent computing characteristics, it is researched and used to set the PID parameters on line, which are the proportional coefficient, the integral coefficient and the differential coefficient. To test the controllers, several experiments are performed. The computer simulation results show that the DNA-PID controllers have faster respond speed and less overshot, which can meet the need of robot control

Optimization Analysis of Thin-Walled High Pier

According to the restriction of the stability and intensity, size optimization of the high piers’ section is calculated by using the current FEM software ANSYS, by means of differential coefficient. The results of the calculation and analysis indicate that the parameter optimization of the piers’ section of Long-span continuous rigid frame bridges is feasible by using the optimization model together with the finite element method, and the results are provided reference for optional design of similar bridge