Papers by Keyword: Electromechanical Coupling

Abstract: The linear motor feed system can realize high-precision motion with high-speed and high-acceleration, which has a broad application in high-speed machine tools. In its unique zero transmission structure, the motor is connected directly with the mechanical system. The thrust harmonics and other disturbances act on the motor mover directly, which makes the tracking fluctuation more prominent. The traditional accuracy and repeatability of positioning cannot reflect the precision of the linear motor feed system in the process of high-speed movement. In this paper, a novel precision evaluation method which takes the dynamic precision as the index is proposed for the linear motor feed system in high-speed machine tools. The performance and precision of linear motor feed system are evaluated by the transient error, steady-state follow error and tracking fluctuation, respectively. Then the servo control model is established oriented to dynamic precision. The influences of NC instructions, servo system and mechanical system on the dynamic precision are discussed. It can be obtained that this new evaluation method on the precision can evaluate systematically the performance of the linear motor feed system in high-speed machine tools. Meanwhile it can reveal efficiently main factors which lead to the decline of dynamic precision and propose effective improvement methods.

Abstract: In the paper dynamic electromechanical coupling between the structural model of the rotating machine drive system and the circuit model of the asynchronous motor has been investigated. By means of the computer model of the rotating machine drive system the results of experimental testing have been confirmed. From the obtained results of computations and measurements it follows that the coupling between the considered rotating system and the installed rotary dampers with the magneto-rheological fluid (MRF) results in effective energy dissipation leading to significant reduction of undesired torsional vibrations.

Abstract: To realize the movement of high-speed, high-precision positioning, satisfy the requirement of the numerical control processing equipment and high precision, based on high performance motion control platform driven by linear motor, an optimized for high performance XY table structure design, the broadband modal coupling modeling and simulation movement, dynamics analysis and controller design, such as content, high performance motion platform organization structure optimization, the global optimization of mechanical system and electrical system. Eventually for high performance sports mechanism design, modeling method and system control method provides the key techniques such as solution, and to develop more high performance motion control of linear motor driven platform prototype machines.

Abstract: For solving the separate problem of electronic equipments structure and electromagnetic design, software system for the multi-field-coupled and multidisciplinary optimization (MDO) of electronic equipments is developed, based on electromechanical coupling theory, using parameterized modeling, MDO technology. The result of applied in reflector antenna and high density case shows that the system can promote analysis and design quality, shorten the design cycle, reduce the cost of design.

Abstract: Through the establishment of motor electromechanical coupling vibration model, torsional vibration characteristics of motor is analyzed in starting process. With 1000T lubricating oil ship electric propulsion shafting as the object of study, the free vibration and the forced vibration characteristics are analyzed. In two cases of considering the electromagnetic excitation torque and without considering the electromagnetic excitation torque, the responded vibration of electric propulsion shafting is calculated. The low noise design of the motor and propulsion shafting provides a theoretical basis.

Abstract: For the dynamic modelling and simulation of electromechanical coupling systems, the corresponding vector bond graph procedure is proposed. Based on the kinematic constraint relations of rigid body, the vector bond graph procedure for modelling spacial multibody systems with revolute joint is described. For the difficulties brought by differential causality in the system automatic modeling and simulation, the effective decoupling method is proposed. As a result, the unified modelling and simulation for electromechanical systems are realized, its validity is illustrated by the robot system driven by electrical motors.

Abstract: The characteristics of the self-synchronization in the offset self-synchronous system are put forward. In the paper, based on Lagrange principle, a dynamic model is derived to give its electromechanical-coupling model, which is provided with many variable no-linear characters. A serious of the practical phenomena in the transition process of the system is reasonably explained using the numerical solution simulation, and the variations rules of each parameter in the system are discussed at several types of the typical status. Finally the characteristics of the self-synchronization in the system are generated under the action of the electromechanical coupling. The visually processes are shown in the simulation results, for which the conventional mechanic models are unavailable to explain quantitatively, in which the vibration machines implement fully the transition from asynchronous to synchronous state or from one type of synchronous state to other type. It is fully verified that the system is with the self-healing synchronous ability, and the synchronous movement rules in the electromechanical coupling system are also revealed. For its research not only it is useful to explore the electromechanical coupling model of the offset self-synchronous system, but also it is in-depth to study synchronous motion rules of the self-synchronous system, and it is of the theoretical and practical importance.

Abstract: This paper has introduced electromechanical coupling characteristics in portable facility for bearing load, considered model ,according to legs supporting gait when people walking, established the load torque compensation model , and a mathematical model of knee position control system which is made of the servo valve, hydraulic cylinders and other hydraulic components, designed hydraulic cylinder position control loop in case of existing load force interference compensation, and used the method of combining the PID and lead correction network for frequency domain design ,ensured system to meet a certain stability margin. The simulation results show that this position control method can servo on the knee angular displacement of normal human walking, reached a certain portable facility bearing load and assistant power effect, at the same time, met the needs of human-machine coordinated motion.

Abstract: This paper has introduced electromechanical coupling characteristics in the lower extremity exoskeleton systems, considered model ,according to legs supporting gait when people walking, established the load torque compensation model , and a mathematical model of knee position control system which is made of the servo valve, hydraulic cylinders and other hydraulic components, designed hydraulic cylinder position control loop in case of existing load force interference compensation, and used the method of combining the PID and lead correction network for frequency domain design ,ensured system to meet a certain stability margin. The simulation results show that this position control method can servo on the knee angular displacement of normal human walking, reached a certain exoskeleton boost effect, at the same time, met the needs of human-machine coordinated motion.

Abstract: There is still lack of effective modeling and simulation method for complex electromechanical coupling system. Modelica is a multi-domain unified modeling language to solve the modeling and simulation problems of the complex and heterogeneous physical systems. Dymola is a Modelica-based modeling and simulation platform for the complex physical systems. In this paper, the dynamics model of the permanent magnet synchronous motor (PMSM)-precision reducer system is established using Lagrange-Maxwell equation. The simulation model of this system is set up with Modelica language. The simulation of the system is realized in Dymola. Results show that the system can respond to good static and dynamic characteristics under a given speed for different loads. The dynamics model of the PMSM-precision reducer system can be further used in system control and optimization. The proposed modeling and simulation method based on Modelica may be commonly applied to other complex electromechanical systems.