Pulse Control Signal Research Articles

Привод подачи режущего инструмента фрезерного станка для обработки вафельного фона

The paper describes the process of designing the cutting tool feed drive of a special metalworking machine, which due to the circuit solution and automatic control system will increase the productivity of processing one cell of wafer background on sheet material up to 10–15 seconds. On the basis of the analysis of the technology of milling of a given regular pattern of wafer background and peculiarities of the equipment operation it proposed to replace the traditional ball bearing gear in the cutting tool feed drive with a flat combined crank-slide mechanism. Geometrical parameters of the lever transmission mechanism calculated in accordance with the known dimensions of the regular cell pattern and the recommended value of the angle of motion transmission. The analysis of kinematic and power characteristics of the lever mechanism allowed to justify the technical characteristics of the electric motor. In order to realize the required trapezoidal law of the output link speed change, the inverse problem of kinematics solved, numerical values of the instantaneous angular velocity of the input crank and pulse control signals to the servomotor obtained.

Generation of Multidirectional Mirror Symmetric Multiscroll Chaotic Attractors (MSMCA) in Double Wing Satellite Chaotic System

Based on the multilevel-logic pulse control method the simplified mirror symmetric multidirectional multiscroll chaotic attractors are designed via multilevel pulse excitation sources. This technique is based on the non-autonomous approach that generates multidirectional mirror symmetric multiscroll chaotic attractors (MSMCA) without changing the original nonlinear functions. The complex double wing satellite system is taken as an example to explain the mechanism of this scheme. In this paper, the multilevel pulse excitation sources are used in the quadratic terms of the satellite system (for mirror symmetry) and in the transformed state variables (for multidirectional multiscroll attractors) simultaneously to generate multidirectional MSMCA. By using the multilevel logic pulse control signal in double wing satellite system, a complete family of multidirectional MSMCA including 1D, 2D and 3D MSMCA is generated. Further, we explored that the arbitrary multidirectional (MSMCA) can be designed by introducing pulsed excitation in corresponding state variable directions (1D, plane (2D) or space (3D)). Numerical simulations together with theoretical analysis show the flexibility and effectiveness of the proposed methodology.

Adaptive switching vibration control of flexible piezoelectric structure

This paper aims at developing a compact-size and low-power active control system for harmonic vibration attenuation. A new switching control system is proposed for this purpose. In the new system, the power amplifier in charge of voltage amplification is replaced by a filterless switching circuit, which directly receives digital pulse control signal from the external adaptive controller and produces high voltage in pulse form across PZT. The compact circuit design combining with adaptive filter dramatically simplifies the control system by removing digital-to-analog converter and voltage (current) feedback originally used in most amplifiers for less distortion. In particular, the hybrid switching control mode of the new system is specially addressed. The theoretical and experimental analysis reveals that hybrid switching control brings a great power reduction at the price of small control performance loss. Finally, the validating experiments are carried out, and experimental results show remarkable effectiveness for vibration suppression.

Performance comparison of automatic peak detection for signal analyser

The aim of this paper is to propose a new peak detection method for a portable device, which know as modified automatic threshold peak detection (M-ATPD). M-ATPD evolves out of ATPD with a focus on reducing computational time. The proposed method replaces the clustering threshold calculation in ATPD with a standard deviation threshold calculation. M-ATPD reduces computational time by 2 times faster compared to ATPD for control signal and 8.65 times faster compared to ATPD for raw biosignals. Modified ATPD also shows a slight improvement in terms of detection error, with a decrease of about 6.66% to 13.33% in peak detection of noise signals. Modified ATPD successfully fixes the error of peak detection on pulse control signals associated with ATPD. For raw biosignals, in total M-ATPD achieved 19.41% lower detection error compare to ATPD.

Novel broken line detection circuit for multi‐cells Li‐ion battery protection ICs

To reduce the excessive power consumption and eliminate the battery voltage imbalance caused in conventional method, a novel broken line detection scheme for Li-ion battery protection integrated circuits (ICs) is presented in this study. The main part of the proposed circuit consists of pull-up, pull-down current source, source-driven MOS, a control switch and a bias current source. A narrow pulse control signal is adopted to trigger broken line detection periodically so as to suppress the detection current consumption, while the disadvantage of battery voltage imbalance is overcome. The proposed circuit has been implemented in a seven cells Li-ion battery protection IC with 0.18 µm 45 V bipolar-CMOS-DMOS process successfully. The experimental results confirm that the chip can reliably detect the disconnections of Li-ion batteries and take protective measures in a wide cell voltage range from 2.2 to 4.2 V. Furthermore, based on the derivation in this study, the proposed technique can significantly reduce the detection current consumption of each cell, which is well beneficial for low power consumption and battery voltage balance.

Experimental Research of Hydraulic Cylinder Speed Control System Based on High-Speed On-Off Valve

Series and parallel application schemes between high-speed on-off valve and hydraulic cylinder are proposed to control the speed of hydraulic cylinder based on the analysis of high-speed on-off valve flow characteristics. The duty cycle of pulse control signal was changed according to the displacement of hydraulic cylinder to control the speed of hydraulic cylinder and weak the impact. The speed and acceleration curve of hydraulic cylinder were achieved by the means of experiment with FESTO. Experimental results show that, two application schemes can both control the speed of hydraulic cylinder effectively. Series application scheme can be only applied to small flow hydraulic system; parallel application scheme has wider application.

Design of Direct-Control Hydraulic Cylinder Speed Control System Base on High-Speed On-Off Valve

Application of high-speed on-off valve in the hydraulic speed control system was researched in this paper. The direct-control circuit application of high speed on-off valve is proposed to control the speed of hydraulic cylinder. The duty cycle of pulse control signal was changed according to the displacement of hydraulic cylinder to control the speed and weak the impact. The speed and accelerated speed curves of hydraulic cylinder were achieved by the means of simulation with Simulink and experiment with FESTO is obtained, and research result shows that the applied scheme can effectively control the speed of hydraulic cylinder effectively.

Design of Bypass-Throttle Hydraulic Cylinder Speed Control System Base on High-Speed On-Off Valve

Application of high-speed on-off valve in the hydraulic speed control system was researched in this paper. The bypass-throttle circuit application of high speed on-off valve is proposed to control the speed of hydraulic cylinder. The duty cycle of pulse control signal was changed according to the displacement of hydraulic cylinder to control the speed and weak the impact. The speed and accelerated speed curves of hydraulic cylinder were achieved by the means of simulation with Simulink and experiment with FESTO is obtained, and research result shows that the applied scheme can effectively control the speed of hydraulic cylinder effectively.

Design of Hydraulic Cylinder Speed Control System Base on High-Speed on-Off Valve

In order to study the Application of high-speed on-off valve in the hydraulic cylinder speed control system, series and parallel application schemes between high-speed on-off valve and hydraulic cylinder are proposed to control the speed of hydraulic cylinder. The duty cycle of pulse control signal was changed according to the displacement of hydraulic cylinder to control the speed of hydraulic cylinder and weak the impact. The simulation curve compared with the experimental results show that, two application schemes can both control the speed of hydraulic cylinder effectively. Series application scheme can be only applied to small flow hydraulic system; parallel application scheme has wider application.

An experimental study on micro wire-EDM of polycrystalline diamond using a novel pulse generator

This paper presents a new pulse generator for cutting of polycrystalline diamond (PCD) by micro wire electrical discharge machining (micro wire-EDM). The pulse generator using anti-electrolysis circuitry and digital signal processor-based pulse control circuit was developed to suppress damages on the machined surface of PCD while achieving stable machining. A novel pulse control method was proposed to provide high-frequency pulse control signals with a period of off duty cycle for reionization of the dielectric in the spark gap so as to reduce the consecutive occurrence of short circuits. A series of experiments were carried out to investigate the effect of open voltage on machining performance in terms of material removal rate, slit width, thickness of the damaged layer on machined surface, and surface finish. An increase of open voltage increases peak current, thus producing greater discharge energy and, thereby, contributing to improvements in material removal rate, but leading to larger slit width and thickness of the damaged layer and worse surface finish. Experimental results not only demonstrate that the developed pulse generator could achieve satisfactory machining results but also have verified the applicability of this new technique in micro wire-EDM.

Design, analysis and experimental study of a high-frequency power supply for finish cut of wire-EDM

This paper presents the development of a high-frequency power supply for surface quality improvement of wire electrical discharge machining (wire-EDM). A novel fixed pulse-width modulation pulse control method is proposed to generate high-frequency and short-duration pulse control signals. A spark gap model using a resistance–capacitance (RC) circuit and a Zener diode is proposed for circuit design and simulation analysis. Tests revealed that the developed power supply using anti-electrolysis circuitry and digital signal processor-based pulse control circuit can provide very low discharge energy pulses with a frequency of 4.4 MHz, discharge duration of 90 ns and a peak current of 1.2 A. Experimental results demonstrate that a pulse duration ratio (defined as a ratio between pulse duration of positive polarity and that of negative polarity) of three can reduce the electrolytic effect of tungsten carbide for the machining conditions of high discharge frequency more than 500 kHz.

Model-based analysis of dynamics in vergence adaptation.

We previously proposed a model to study the dynamics of disparity vergence responses. This model was based on known physiology and consisted of pulse and step neural control processes feeding a linear second-order oculomotor plant. Here, we apply a slightly modified version of that model to analyze the influence of short-term adaptation on vergence dynamics. This analysis showed that, unlike normal vergence responses, adapted responses could not be accurately simulated without a delay between the step and pulse components. Through simulations of normal vergence and adapted vergence responses, we found a strong correlation between delay of the step signal and the size of the movement overshoot. This correlation suggests a strong interaction between neural process generating the pulse and step motor control signals.

Boosted charge transfer preamplifier for low power Gbit-scale DRAM

A new charge transfer preamplifier scheme is developed for low power and high density DRAMs. It employs a boosting method with a MOSFET capacitor for a high voltage precharge level and a pulse control signal for a charge transfer switch. The new scheme increases the sensing margin and enhances the sensing speed under 1.5 V operation with a small area overhead. It also leads to a wider design window for a charge transfer switch as the supply voltage scales down.

The problem of the time-optimal turning of a manipulator

Two types of manipulator that perform three-dimensional motions are considered, and the control problem in which the manipulator rotation is performed in minimum time is studied. The rate of rotation of a rigid body about an axis rises as the moment of inertia about this axis falls. Manipulator control amounts to a problem of the rotation of a system of rigid bodies about an axis. In addition to the angle of rotation, there is a further controlled coordinate, whose variation can vary the moment of inertia about the axis. Assuming that the moment of inertia can be stantaneously “frozen” (that pulse control signals are possible), the in-time-optimal control modes were found in /1, 2/, (see also Akulenko, L.D. et al., “Optimization of the control modes of manipulation robots”, Preprint 218, In-t. Problem Mekhaniki Akad. Nauk SSSR, Moscow 1983). In these modes, the rotation, occurs in the entire time interval with minimum moment of inertia about the axis of rotation. The rotation when there are constraints on the control (pulse control signals are not permitted) was considered in /3/. Numerical studies there led to the false conclusion that, in the optimal motion, with a finite number of control switchings, the moment of inertia is also a minimum throughout the time interval. Below, for a set of extreme configurations, a control is constructed for the two types of manipulator, which satisfies the Pontryagin maximum principle, when there are constraints on the control signals. During its rotation the manipulator section then performs oscillations about a position corresponding to minimum moment of inertia about the axis of rotation. It is shown that the motion considered in /3/, which contains a singular mode with minimum moment of inertia, is not optimal. The motion which satisfies the maximum principle is compared with it. There can be a singular mode in the optimal motion /4/ only when the number of control switchings is infinite.

Late agonist activation burst (PC) required for optimal head movement: a simulation study.

Fast as possible (time optimal) single joint movements throughout the body are characterized by the triphasic (3 pulse) pattern of activation in the agonist and antagonist muscles. Simulation studies using a sixth order, non-linear model were undertaken to determine the relationship between time optimal movement and three pulse control. Exhaustive exploration of the multidimensional space formed by descriptive parameters of the control signal yielded control signals which drove the model to produce optimal movements. The result of these one to two week computer simulation runs was that if the limb is required to stay close to the target immediately after the end of the control signal, the fastest movements are produced by a three pulse control signal.