Papers by Keyword: Active Damping

Abstract: The electric base load of milling machine tools has a high share of the machine’s total energy consumption. An approach to decrease the energy demand per workpiece is to shorten the machining time by raising the material removal rate. The maximum feed depends on the tool’s wear resistance while the maximum depth of cut is often limited by the chatter stability of the machine. In this paper active damping is used to damp chatter vibrations, which leads to a higher depth of cut. To evaluate the decrease of energy consumption for any workpiece, a modeling methodology for the energy demand of machine tools was developed, which is presented in this paper. The methodology is able to estimate the energy requirements of the spindle during cutting, of the feed drives, of the auxiliary equipment and of the base load. The numerical results were experimentally validated by different 2.5D machining processes, with good agreement between the simulation model and the experimental results. Therefore, the proposed methodology can be used effectively for calculating the total energy required for the machining of any workpiece. In addition, the structural dynamics of the machine tool, the active damping system and the cutting process were modeled in order to simulate the chatter stability. This enables a straightforward determination of the optimum cutting parameters as well as a comparison of different milling part programs, both in terms of the energy demand. Furthermore, it is possible to evaluate the energy conservation by active damping and to point out for which cutting processes active damping is useful.

Abstract: Piezoelectric actuators are more and more common in many different technical and precision industries. Mechatronic systems which combine them with mechanical models and steering recently are used in plenty practical applications. In this paper, discrete mechatronic systems have been compared relating to known passive vibration isolation method and active that has been additionally introduced to considered systems. Requirements for the systems have been given in form of poles and zeros. Basing on amplitude response functions and dynamical flexibilities, damping performance in both cases has been investigated.

Abstract: This paper mainly states that under the PID program control, syntactic foam cantilever beam and piezoelectric composite cantilever beam which are studied with the momentary force and the alternating force signal, in the effective of active damping. The vibration stopping time changes under the momentary force and the amplitude changes under the alternating force signal. Comparing under the same initial amplitude, the amplitude changes of syntactic foam cantilever beam and piezoelectric composite cantilever beam under the active damping.

Abstract: In this paper, the influence of gird-side and inverter-side inductance on LCL-filter performance is studied. The design method of LCL-filter applied in three-phase shunt active power filter (SAPF) is proposed. An active damping strategy using the current feedback of the filter capacitor is adopted to suppress the resonance. A practical example is designed using the proposed design procedure. Finally, Simulation and experimental results verify the feasibility of the design method.

Abstract: To improve the stability and output voltage quality of inverter, an new repetitive control strategy for 400Hz Constant Voltage Constant Frequency (CVCF) inverter has been proposed . Based on active damping, this strategy damps the oscillations on the output LC filter of inverter under unload or light load. Using state-observer to weaken the impact of time delay in digital control, a 5.5 kW one-phase 400Hz inverter prototype by this strategy has been tested.The result shows that low THD (about 1.5%) with inductive loads and fast error convergence (2 fundamental periods) can be achieved by this strategy which can be demonstrated to be brief and effective.

Abstract: In Multi-converter power electronic systems, load converters exhibit constant power load (CPL) behavior for the feeder converters and tend to destabilize the system. In this paper, Buck DC-DC converters are taken as an example, and the implementation of active-damping techniques has been shown to analyze the stability of multi-converter power electronic systems. Moreover, active damping is generally implemented by a feedback loop, which produces the effect of a virtual resistor and damps the oscillations, the proposed active-damping method can overcome the negative impedance instability problem caused by the CPLs. The effectiveness of the proposed approach has been verified by Matlab/Simulink simulations.

Abstract: Vibration suppression control considering elastic part deformation is one of the indispensable issues in the precision engineering field and a high-density LSI circuit processing[1]. This study aims at suppressing the induced vibration at rapid positioning operation using the N4SID (Subspace State Space model Identification) Model Referenced predictive Anti-phase pitch Driving Active Damping (N4SID-MRAD) and improve the positioning performance limit generated by conventional PID feedback control with existing actuator, which has low dynamic characteristics with a time lag. This control method consists of reduced order model identification (model order reduction using N4SID concept: offline process) and predictive control using the counter pitch driving based on the model output (: on-line process). This method was applied to principal axis vibration suppression of three axes positioning machine driven by a ball screw feeding mechanism to control the probe tip end positioning in feeding rod axis. The result showed that amplitude of residual vibration at the probe tip end suppressed with conventional PI controlled and the 77% performance improvement under low stable conditions that Balanced Realization could not be applied.