Circuit Of Machine Research Articles

Multiprocessor systems based on FPGA for receiving and processing data from the position sensors of the manipulator elements with controlled bending

Key moments of technique of reception and processing of information from the MEMS position sensors in the information system of the manipulator built on the basis units with controlled bend is discussed in detail. The differences in the procedure for construction of multiprocessor information systems based on the new programmable logic integrated circuits large capacity which provide the use of soft-core processors is presented too. The results of qualitative comparison of the solutions obtained by use state machine circuits and schemes based on soft-processors is shown. As an example, consider the structure developed multiprocessor information system and variants of its hardware and structural implementation.

Steady state analysis of a three phase indirect matrix converter fed 10 HP, 220 V, 50 Hz induction machine for efficient energy generation

The matrix converter or pulse width modulated frequency changer, invented in the mid-1980s, is a direct power conversion device that can generate a variable voltage and frequency from a variable input source. Industrially, it is applied in adjustable speed control of induction motor drive, power quality conditioner, and traction applications. The aim of this paper is to evaluate the steady state characteristic behavior of an induction machine in terms of its speed and torque when driven by a three phase indirect matrix converter at reduced harmonics. Similarly, projecting an AC-AC matrix converter that ensures a uniform synchronization in frequency and voltage supplies between the three phase wound rotor machine and the transformer's grid voltage supply is discussed in the Scherbius scheme. The different methods of torque calculations pertaining to some selected machine circuit diagrams are presented for comparison and analysis. Emphasis on the torque-speed characteristics of the machine at varied resistance and slip values were graphically analyzed in MATLAB to determine the degree of torque-speed dependence on the rotor resistance and slip. The overall behavior of the machine under motoring, plugging, and regenerative modes was considered in this work, while a detailed Simulink modeling of an indirect matrix converter on the Scherbius drive scheme is also presented for further analysis.

Implementing circuit of combined finite state machine with FPGAs

Implementing circuit of combined finite state machine with FPGAs

ON THE CALCULATION OF RESISTANCE ASYNCHRONOUS MACHINE

The article describes two ways to calculate the resistance of the equivalent circuit of induction motors. As a basic resistance values for which a comparison is made of the results of calculation adopted by the resistances of the equivalent circuit of asynchronous motors with the cage and wound rotor, calculated in [1]. The method of calculation and compiled forms (sequence) for calculating the resistance of asynchronous motors in two versions. The form of the first embodiment is fully consistent with the recommendations of the guidelines [2]. Comparison of resistance induction motors found on the first form and showed that the majority of resistances are unacceptably large differences with the basic values. Therefore, only some of the resistance values calculated by the formulary of the first embodiment can be used for analyzing the properties of electric motors, in particular for determining the current sent to the point electric short circuit in electric networks. However, most of the resistance values are unsuitable for calculating the performance of the induction motor. Therefore, the second option is made up Form. The article shows that not all relations given in [2], are suitable for determining the resistance of equivalent circuits of induction machines. Therefore, the second method uses a form just some of the relationships that are recommended in the guidelines [2]. In the application of [2] for the calculation of short circuit currents sufficient to use only the equivalent impedances of the equivalent circuit of the induction motor in nominal mode and initial start-up time of the machine. They are determined by the calculation sheets of the first embodiment. In the case of the calculation of performance or mechanical characteristics of the induction motor to determine the parameters of the equivalent circuit of induction machines to use the second variant form of calculation proposed in this paper.

Estimation of High-Frequency Parameters of AC Machine From Transmission Line Model

This paper proposes a modeling method to estimate the high frequency (HF) characteristics of stator winding in an ac machine. From the frequency response of windings, the proposed method extracts frequency-dependent per-unit-length (PUL) transmission line parameters, which are simplified to a PUL equivalent circuit, including low-frequency and HF components. The newly developed PUL circuit provides a simple distributed-element winding model that captures HF behaviors accurately, and the modeling procedure can be easily adopted for an initial design with simulation data. To verify the proposed method, input impedance from a constructed equivalent circuit of an induction machine was compared with the measurement results. In addition, the concept of effective length, which is involved with antiresonance phenomena, is presented based on the proposed method.

Study on Electrical Control System of X62W Milling Machine Based on PLC

With the continuous development of milling machine, the normal milling machine was not suitable with modern processing. In order to adapt to the requirements of modern production process and quality, the electrical control system of milling machine need be improved. The electrical control system and circuit of X62W milling machine is analyzed and designed. The PLC program is compiled. All of it is proved to be reasonably and feasibly based on the experimental results.

Design of Embedded Microcontroller for Controlling and Monitoring Blood Pump

Abstract The peristaltic pump has a vital role for transporting the blood in the extracorporeal circuit of hemodialysis machine. Such a pump consits of a stepper motor, gear box and rotor shaft with two roller attached on it. The transported volume of the pump depends on the tube segment pressed by roller. Therefore, the deviation in the amount of delivered fluid may occurs. It is a problem when it is used in the medical device with high accuracy requirements such as hemodialysis machine. To overcome such a problem, the transport of fluid need to be controlled. The aim of this work was to design and implement of an embedded microcontroller for controlling and monitoring fluid transport in the peristaltic pump. An electronic hardware which consists of STM32F4 development board, stepper motor driver circuit, current sensor, magnetic sensor and arterial presure sensor circuits was developed in parallel with embedded software development. The embedded sofware consists of routines for monitoring current sensor, pressure sensor, and magnetic sensor, as well as routines for pump speed controller. The STM32F4 board which consits of ARM Cortex M4F microcontroller was chosen because of the trade off between price, performance, and low power consumption. The peristaltic pump system was tested with the mixture of water and glycerin with certain composisition and having viscosity simular to human blood. The validation was also be performed by comparing the results with the measurement conducted using turbine flow meter. The results shows that the performance of the controller is working as expected.

Modeling and Numerical Simulation of the Internal Inductive Coupling Effect in a Magnetohydrodynamic Pump

The equivalent electric circuit of an electrical machine is a powerful tool for analysis and it can also be very helpful in the design stage. In this paper, we present the work carried out to obtain the equivalent circuit of an electromagnetic pump, which consist of two other machines series connected. Each of these machines, a transformer-type one and an electromagnet, are affected by the magnetic field created by the other. This means that the simpler equivalent circuit formed by joining the well-known equivalent circuits of each machine is not valid. To understand the discrepancy between this simpler equivalent circuit and the real behavior of the electromagnetic pump, numerical simulation and experimental validation were used. As a result, a new equivalent circuit is proposed that considers an inductive coupling that exists between both machines.

Implementing circuit of moore fsm with two sourses of codes

The method is proposed for reducing the number of LUT elements in the circuit of Moore finite state machine. The method is based on the using two sources of pseudoequivalent states. The special multiplexer executes choice for the source of input memory functions. The system of microoperations is implemented by embedded memory blocks. An example is given for application of the proposed method

Dynamic properties of the torque-control system in an electric drive with a double-fed asynchronous machine

Dynamic properties of an open-loop system of control of the electromagnetic moment that is part of an electric drive with a double-fed asynchronous machine have been considered. Analysis of a system of control of the electromagnetic moment with a subordinate system of control of currents of the stator and rotor windings of an asynchronous machine under the frequency control of the speed has been performed. Mathematical models of the elements comprising the system of the electromagnetic-moment control have been considered. These models describe the power part, the current controllers, and the regime former. In description of the elements of the electromagnetic-moment control system, the saturation of the main magnetic circuit of the machine has been taken into account. The program of the simulation of the processes is mainly aimed at the investigation of the effect of the speed of response of the current-control system on the dynamics of the open-loop system of the electromagnetic-moment control. Results of the simulation of the processes in the system of the electromagnetic-moment control at different speed of response of the current-control system are given. It has been shown that, with a decrease in the speed of response, the current controller begins losing the capability of compensating the effect of the disturbing action (the asynchronous machine speed is taken as this action). As a result, the orientation of the coordinate system, which is implemented by the moment controller, is disturbed and the dynamic characteristics of the systems of control of the electromagnetic moment and speed become worse. At a given speed of response of the current-control system, the characteristics of the efficiency of an open-loop system of control of the electromagnetic moment depend on the magnitude and speed of change in the controlling and disturbing actions. The dynamics of the system of the moment control is illustrated by graphs of transient processes in the case of a stepped setting of the controlling action and of the linear increase in the disturbing action. Based on the results of the investigations performed, the main conclusions and recommendations have been made.

Hydraulic Device for Simulation of Pressure Shocks

Abstract This work is focused on the design of a hydraulic device on which simulations of pressure shocks can be performed. The hydraulic device was constructed to allow simulations of pressure shocks transferred directly in operating conditions because simulation programs for hydraulic accumulators have only theoretical values while simulation on the designed hydraulic device enables obtaining specific readings directly in operating conditions that can be set. At the first control measurement on the hydraulic device, there occurred pressure shocks generated by the hydraulic device itself, these pressure shocks being undesirable in hydraulic circuits. In order to eliminate pressure shocks in the circuit, a diaphragm accumulator was added to the hydraulic device and was used to verify the function of simulating pressure shocks and eliminating undesirable pressure shocks. During the second control measurement on the hydraulic device, a reduction of unwanted pressure shocks was shown with the help of added diaphragm accumulator, thus the function of the hydraulic device to simulate pressure shocks was confirmed, which may also refect practical application in hydraulic circuits of mobile machines.

Supplementation of standard pre‐oxygenation with nasal prong oxygen or machine oxygen flush during a simulated leak scenario

The presence of a facemask leak significantly reduces the effectiveness of pre-oxygenation and increases the risk of post-induction hypoxia. We randomly assigned 24 healthy volunteers to a six-period crossover trial with and without a simulated facemask leak. Pre-oxygenation was performed using a standard anaesthesia machine circuit supplemented either by nasal prong oxygen or by anaesthesia machine flush oxygen. Each intervention was completed with both 3-min tidal breathing and 8 deep breath techniques: end-tidal oxygen fraction was used as the measure of pre-oxygenation effectiveness. The presence of a stimulated mask leak significantly reduced the effectiveness of pre-oxygenation regardless of the breathing method used. With a simulated facemask leak introduced, the mean (SD) end-tidal oxygen fraction with the 3-min tidal breath technique was 74.7 (9.3)% compared with 57.5 (6.2%) for the 8 deep breath technique with 3-min tidal breathing and a leak. End-tidal oxygen fractions increased by 11.0% (95% CI 7.8-14.3%) (p<0.0001) with the addition of nasal prong oxygenation and 16.8% (13.6-20.0%) (p<0.0001) with machine oxygen flush compared with standard pre-oxygenation. When a leak is present, 3-min tidal breathing with either nasal prong or anaesthesia machine flush oxygenation is an effective pre-oxygenation method, and preferable to the 8 deep breath method.

Thermodynamic analysis of heat-energized refrigeration machine with carbon dioxide

The stages of creating a circuit-cycle design of a heat-energized refrigeration machine using carbon dioxide as a working fluid are considered in the paper. The purpose of the machine development is to get cold using a low-temperature heat of enterprises, as a way of saving energy and material resources. The thermodynamic analysis for generating a machine circuit using the "cycle method", the energy and exergy analysis of parts and the machine in general, in a wide range of temperatures and pressure in the gas heater, was conducted. The analysis showed that the machine can work in a wide range of the heating source and different pressures in the gas heater, but their change affects the effectiveness of other machine parts, which affects the exergy efficiency of the machine and its parts. The obtained results of the analysis are useful for further implementation of the machine, namely modeling, design and selection of machine parts for the maximum efficiency.

CG-in-PG architecture implementation for power reduction in FSMs

By gating the power supply of the inactive part of the finite state machine (FSM) circuit, total power is reduced but the active part continues to dissipate power. So, there is a possibility of applying clock gating (CG) to the active part of the power-gated FSM. A transition may happen in which the states do not change but output changes. This issue has not been addressed by the conventional CG, so, for reducing the switching of register during CG and to overcome the issue, conventional CG has been modified by splitting the input latch of the FSM circuit. The architecture termed as CG-in-PG is designed in such a way that when one sub-FSM is inactive it adopts power gating (PG) for power reduction and other sub-FSM seeks for possible CG during its active period. So, both the sub-FSM is capable of reducing power either by PG or by CG depending on whether it is in inactive mode or active mode. To the best of our knowledge, this is the first ever approach of applying CG after power-aware genetic algorithm (GA)-based bi-partitioning and encoding of FSM for power-gated design. The synthesis of the proposed design has been implemented in Cadence digital synthesis tool. The results show 36.94% average saving after applying CG-in-PG with respect to only PG.

Incidence and prediction of inadequate preoxygenation before induction of anaesthesia

BackgroundPreoxygenation aims to obtain an expired oxygen fraction (FEO2)≥90%. Little is known about the incidence and predictors of inadequate preoxygenation in the clinical setting. Patients and methodsOver a 12-month period, 1050 consecutive preoperative patients were prospectively included. Preoxygenation was performed for 3minutes with a facial mask using a machine circuit and 12-L/min oxygen flow. Inadequate preoxygenation was defined as an FEO2<90%. A logistic regression was performed to identify incidence and independent predictors. ResultsThe patient characteristics were: age 51±20years, 47% male, BMI of 26±5kg/m2, and ASA score (median [extremes]) of 2 [1–4]. Inadequate preoxygenation was observed in 589 patients (56%). The effective FiO2 delivered was lower in the patients with inadequate preoxygenation than in those with adequate preoxygenation, 95±3% vs. 98±2%, P<0.001. The difference between the FiO2 and the FEO2 was higher (12±6% vs. 6±3%, P<0.0001) in patients with inadequate preoxygenation compared with those with adequate preoxygenation. The independent risk factors for inadequate preoxygenation were: firstly, bearded male (odds ratio [OR] of 9.1 [2.7–31.4] P<0.001); secondly, beardless male (OR 2.4 [1.6–3.4] P<0.001), thirdly, ASA score of 4 (OR 9.1 [2.6–31.2] P<0.015); fourthly, ASA score of 2–3 (OR 2.4 [1.6–3.4] P<0.015); fifthly, lack of teeth (OR 2.4 [1.2–4.5] P<0.006), and lastly age>55 years (OR 1.8 [1.2–2.7] P<0.005). ConclusionInadequate preoxygenation, defined as an FEO2 <90% despite 3-min tidal volume breathing, was a common occurrence. The predictive factors share an overlap with those previously identified for difficult mask ventilation.

A comparison of desflurane consumption according to fresh gas flow.

A comparison of desflurane consumption according to fresh gas flow.

Delivery of sevoflurane to dogs using a Stephens anaesthetic machine

ObjectiveTo investigate the sevoflurane concentrations produced within the Stephens anaesthetic machine circuit (vaporizer in-circle system) at different fresh gas flow rates (FGFRs), temperatures, vaporizer settings and vaporizer sleeve positions when used to anaesthetize dogs of different body sizes. Study designExperimental non-blinded studies. AnimalsEighteen mixed breed dogs, weights 4–39 kg. MethodsAnaesthetic induction with propofol was followed by maintenance with sevoflurane in oxygen via the Stephens anaesthetic machine. In study 1, the vaporizer setting, temperature and circuit FGFRs were altered with the vaporizer sleeve down (n = 3), or in separate experiments, up (n = 3). Delivered (Fi’SEVO) and expired sevoflurane concentrations were recorded. Study 2 determined the vaporizer settings (sleeve up) required to achieve predetermined multiples of minimal alveolar concentration (MAC) of Fi’SEVO when sevoflurane was delivered to dogs (n = 12) of different bodyweights and at different FGFRs. ResultsDelivered concentrations of sevoflurane were sufficient to maintain anaesthesia in all dogs, regardless of bodyweight, FGFR, vaporizer temperature and sleeve position. Fi’SEVO increased with increasing temperature, when the vaporizer sleeve was down, when vaporizer setting was increased and when FGFR was decreased. As the FGFR increased or the dog’s bodyweight decreased, higher vaporizer settings were required to produce the same Fi’SEVO. The median Stephens vaporizer settings to achieve an Fi’SEVO of 1.3 MAC ranged from 4.3 to 5.0 for a small dog (1–10 kg), 2.5 to 5.6 for a medium dog (15–25 kg) and 2.5 to 3.5 for a large dog (30–40 kg), depending on the FGFR. Conclusion and clinical relevanceThe Stephens anaesthetic machine can deliver to dogs, weighing 4 kg and above, concentrations of sevoflurane sufficient or in excess of that required to maintain anaesthesia, at temperatures from 10 to 35 °C, FGFRs of 1 to 5 times the patient’s estimated metabolic oxygen requirement and at any vaporizer sleeve position.

Von Willebrand Factor Activity Increases Following Automated But Not Simple Red Blood Cell Exchange Transfusion In Sickle Cell Disease Patients

BackgroundRed blood cell (RBC) exchange transfusion is a commonly used therapy for acute and chronic complications of sickle cell disease (SCD). However, the therapeutic benefit of RBC exchange in many clinical situations is not well established. RBC exchange can be performed in two ways: 1) manually, involving repeated cycles of whole blood phlebotomy followed by simple transfusion of donor RBC, or 2) automated exchange utilizing apheresis to rapidly remove patient RBC while returning patient plasma, platelets, and leukocytes along with donor RBC to the patient. Unlike manual exchange transfusion, automated RBC exchange exposes patient blood to high shear stress as blood transits the apheresis machine, reaching wall shear stresses of 30-50 dyne/cm2 (within the range of arterial shear) with regional peak wall shear stresses of over 500 dyne/cm2 (supraphysiologic shear). Increased wall shear stress increases the reactivity of plasma von Willebrand Factor (VWF), in part by enhancing exposure of the VWF A1 domain which is directs binding to the platelet glycoprotein (GP) Ib-IX-V. Increased VWF reactivity has been implicated in SCD pathogenesis, likely by promotion of adhesive interactions between VWF and sickle erythrocytes, platelets, leukocytes, and the vessel wall. HypothesisWe hypothesized that automated RBC exchange would increase the reactivity of VWF as compared to manual RBC exchange in SCD patients. MethodsWe assessed VWF parameters in the plasma of SCD patients before and after manual exchange transfusion and/or automated RBC exchange transfusion performed for non-acute clinical indications. The VWF parameters assessed were VWF antigen level (VWF:Ag), VWF activity (VWF:Act) as assessed by ELISA (DiaPharma) detecting the spontaneous Gp Ib-IX-V binding conformation in the VWF A1 domain, total active VWF (VWF:TA) calculated by VWF:TA = (VWF:Ag) x (VWF:Act), VWF ristocetin cofactor activity (VWF:RCo), and VWF multimer composition. ResultsSix SCD patients on chronic, monthly exchange transfusion support were enrolled in the study. Blood samples were obtained prior to and immediately following multiple separate exchange transfusion episodes for each patient. Three patients underwent only automated RBC exchange transfusion, one underwent only manual RBC exchange transfusion, and two patients underwent both manual and automated RBC exchange transfusion. Compared to normal pooled plasma (NPP), SCD patients prior to RBC exchange transfusion had increased VWF:Ag (1.3-2.1 fold), VWF:Act (mean 124% of normal), and VWF:TA (0.6-2.2, mean 1.52; VWF:TA of NPP= 1.02). There was no statistically significant change in VWF:Ag following manual or automated exchange. There was a statistically significant increase in VWF:Act in patients following automated RBC exchange (mean 25% increase, p<0.05 with range 12%- 53%) but not manual exchange (mean 3.4% increase, range 1.4%-6.3%). In addition, we found an increased VWF:TA following automated (mean 31% increase, p<0.05) but not manual exchange transfusion. Patients exhibiting the highest VWF:TA post-exchange transfusion also had increased VWF:Rco in response to low dose and high dose ristocetin. The patient plasma with the highest VWF:TA post-RBC exchange (3.59) was noted to initiate spontaneous platelet agglutination in the absence of ristocetin. The observed increases in VWF:TA or VWF:RCo did not correlate with differences in VWF multimer composition on non- reducing agarose gels. ConclusionsVWF activity is increased after automated RBC exchange but not manual RBC exchange in adult sickle cell patients on chronic exchange transfusion. These increases are likely a result of shear induced activation of VWF in the apharesis machine circuit. We speculate that the increased VWF reactivity observed following automated RBC exchange transfusion could contribute to VWF-mediated adhesive interactions and aggravate SCD vascular complications, potentially conferring a microangiopathic effect, in certain clinical situations. Maneuvers to decrease automated RBC exchange transfusion-induced VWF activation may lead to improved outcomes for SCD patients requiring exchange transfusion. Disclosures:No relevant conflicts of interest to declare.

A time-of-flight mass spectrometer for monitoring the inhalational anesthesia concentration in the real-time mode

The use of a medical mass spectrometer for measuring the concentration of the gas mixture components in the breathing circuit of an inhalational anesthesia machine in the real-time mode is described. The resolution of the mass spectrometer is M/ΔM = 200, and the detection threshold in terms of the partial pressure of the analyzed gases is 2 × 10−12 mbar. The mass spectrometer is capable of measuring the volumetric content of CO2, O2, and inhalational anesthetic sevoflurane. The respiratory coefficient (CO2/O2) was measured during anesthesia to estimate the patient’s stress reaction to a surgical injury.

Order of Selection and Design of Magnetic Clutches for Sealed Machines

A technique for selection and design of magnetic clutches with highly coercive permanent magnets (barium oxide magnets or magnets produced from such alloys of rare-earth elements as samarium‐cobalt and neodymium‐iron‐boron) for sealed machines (pumps, compressors, mixers) is presented. Magnetic clutches are intended for contact-free transmission of rotary motion across a fixed partition through the interaction forces of permanent magnets. With the use of highly coercive barium-oxide magnets and magnets produced from rare-earth alloys (samarium‐cobalt, neodymium‐iron‐boron), it becomes possible to decrease the overall dimensions of magnetic clutches (Figs. 1, 2). Magnetic clutches are used in sealed machines in dangerous industries. The design of such machines and apparatuses is a difficult procedure in view of the absence of criteria for the selection of magnetic clutches according to basic parameters. The objective of the present article is to develop a technique for selecting and designing magnetic clutches with highly coercive permanent magnets produced from barium oxide and rare-earth alloys. Initial data in the selection and design of magnetic clutches: kinematic circuit of machine; clutch ratio of drive and driven elements of machine; nominal rotational speed of asynchronous electric motor; characteristic of load moment on working unit as a function of rotational speed; mechanical characteristic of asynchronous electric motor constructed from reference data; reduced moments of inertia of rotation for drive and for driven parts of machine; requirements imposed on construction materials and characteristics of working medium; gauge or vacuum-gauge pressure in working cavity of machine or apparatus.