STUDY ON AUTOMATIC BALANCE TECHNOLOGY FOR THE RIGID ROTOR

The theory and application of automatic balance technology for the rigid rotor is re- searched. New analysis about the mechanical model of vibratory system is done in view of feature of automatic balance, and the result is that the accurate model of system can be gained by compensa- tion method and the traditional principle error of balance machines both for soft and hard bearing can be overcome. The automatic balance testing theory for sofi and hard bearing machines is pro- posed. The automatic balance system has been developed and the function and technical key is also introduced in detail.

A study of PID and L1 adaptive control for automatic balancing of a spacecraft three-axis simulator

Purpose–The three-axis simulator relies on the air film between the air bearing and the bearing seat to achieve weightlessness and the frictionless motion condition,which is essential for simulating the micro-disturbance torque of a satellite in outer space.However,at the beginning of the experiment,the disturbance torque caused by the misalignment between the center of gravity of the simulator and the center of rotation of the bearing is the most important factor restricting the use of the space three-axis simulator.In order to solve this problem,it is necessary to set the balance adjustment system on the simulator to compensate the disturbance torque caused by the eccentricity.The paper aims to discuss these issues.Design/methodology/approach–In this paper,a study of L1 adaptive automatic balancing control method for micro satellite with motor without other actuators is proposed.L1 adaptive control algorithm adds the low-pass filter to the control law,which in a certain sense to reduce the high-frequency signal and speed up the response time of the controlled system.At the same time,by estimating the adaptive parameter uncertainty in object,the output error of the state predictor and the controlled object can be stabilized under Lyapunov condition,and the robustness of the system is also improved.The automatic balancing method of PID is also studied in this paper.Findings–Through this automatic balancing mechanism,the gravity disturbance torque can be effectively reduced down to 10−6 Nm,and the automatic balancing time can be controlled within 7 s.Originality/value–This paper introduces an automatic balancing mechanism.The experimental results show that the mechanism can greatly improve the convergence speed while guaranteeing the control accuracy,and ensuring the feasibility of the large angle maneuver of spacecraft three-axis simulator.

A Parallel Interval Computation Model for Global Optimization with Automatic Load Balancing

In this paper, we propose a decentralized parallel computation model for global optimization using interval analysis. The model is adaptive to any number of processors and the workload is automatically and evenly distributed among all processors by alternative message passing. The problems received by each processor are processed based on their local dominance properties, which avoids unnecessary interval evaluations. Further, the problem is treated as a whole at the beginning of computation so that no initial decomposition scheme is required. Numerical experiments indicate that the model works well and is stable with different number of parallel processors, distributes the load evenly among the processors, and provides an impressive speedup, especially when the problem is time-consuming to solve.

A Double Input-parallel-output-series Hybrid Switched-capacitor Boost Converter

A double input-parallel-output-series hybrid switched-capacitor boost(DIPOS-HSCB)converter is proposed which consists of two different kinds of input-parallel-output-series(IPOS)circuits,i.e.,inner IPOS circuit and outer IPOS circuit.Two boost modules and one switched-capacitor network build an inner IPOS circuit based IPOS-HSCB converter and two IPOS-HSCB converters develop the outer IPOS circuit based DIPOS-HSCB converter.With the proposed DIPOS-HSCB converter,a high voltage-gain with low component stress and small input current ripple are achieved.Furthermore,an automatic current balancing function for all input inductor currents can be also achieved using a special carrier phase-shifted modulation scheme.A prototype rated at 200 V/120 W has been developed and the maximum efficiency of the proposed DIPOS-HSCB converter is 95% at 120 W.Both steady and dynamic results are presented to validate the effectiveness of the proposed DIPOS-HSCB converter.