Papers by Author: Guang Ma

Abstract: The pre-stressed modal properties of planetary gears of compound oscillatory roller transmission gear reducer considering the external torque and rotating angular velocity were calculated in this work. For the boundary conditions, the large torque was considered to output gear and angular velocity for applying to middle gear. The resonant frequencies of output gear under external torque were a little higher than the case of no external loads, because the stiffness of gear will be changed with external loads. But the resonant frequencies of middle gear show the no changes under rotating angular velocity, because the low angular velocity and no stiffness change with structure of gear. Finally from the cambell diagram, the calculated resonant frequencies were in the range of safety.

Abstract: To meet the needs of test for compound oscillatory roller transmission (CORT) reducer, A comprehensive test system for precision transmission performance was designed, the test-bed structure and control principal of which were introduced. First, a transmission performance test method was proposed and focused on the transmission performance of velocity ratio, accuracy, and efficiency. Then, user interface based on LabVIEW program was designed, and the transmission performance of torque, angle, velocity, velocity ratio, return difference, efficiency could be displayed. Finally, measurement example on an E80 type CORT reducer has been made, and shows that the proposed test system is suitable for test for these reducers of high-precision drive, high stiffness, high load characteristics.

Abstract: Fiber winding tension control is a key technique in the winding machine which influences the quality of winding product directly. The change of diameter results in the winding tension becoming more complicated, time varying and non-linear and has a severe influence on steady and transient performance of winding system. This paper proposes a novel control scheme, which integrates the feedforward observation algorithm with PID control algorithm. One of the most merits is that it can compensate disturbance value based on the measuring data of rotational inertia and rotational accelerometer in real time. Simulation results show that control system has well qualified with high control precision and high response speed.

Abstract: This paper describes the implementation of semi-passive switching shunt control for electro-magneto-mechanically coupled flexible structures. This simple system consists of a permanent magnet attached to an aluminum beam and a coil placed below the magnet with a switching circuit connected to the end of the coil. The MATLAB Simulink program and dSPACE hardware were employed for realizing the switching mechanism. Switching is done between open-circuit and short-circuits states. When the structure moves away from equilibrium, the circuit is short circuited, thereby dissipating energy, subsequently the system returns back to open circuit state. This novel self-sensing electromagnetic switching damper was compared with the traditional laser-sensing method for vibration control of the structure. The results show that the proposed semi-passive switching shunt damper can be successfully applied to minimize the magnitude of vibrating flexible structures.

Abstract: Thermoforming is one of the most versatile and economical processes available for shaping polymer products. The heating time and heater power must be optimized for obtaining good products efficiently. In this study, the method for calculating the required heat flux was researched at first. In the following step, the analytic solution was studied for getting optimal heating time and heater power. Finally, the relationship between heater power and heating time was discussed. The developed method in this study will be widely used to shorten the cycle time under the condition of satisfying requirements of thermoforming.