Dual Control System Research Articles

A Dual-Loop Control System for Dense Medium Coal Washing Processes With Sampled and Delayed Measurements

A dual closed-loop control system is developed for a dense medium coal washing process. The controller is designed to improve the separation efficiency and energy efficiency of the dense medium cyclone coal beneficiation process simultaneously making use of a model predictive control method and a pumped-storage system (PSS). In the dual-loop control, the outer loop is designed for medium density profile optimization and the inner loop is used for actuator control of the medium supplying circuit, considering the interplay of the energy efficiency and separation efficiency. Mathematical models of the PSS and the magnetite recycle process of the dense medium circuit are developed and employed in the design of the advanced controller. The effectiveness of the designed control system is demonstrated by simulations based on operational data from a South African coal beneficiation plant.

Protective and control relays as coal-mine power-supply ACS subsystem

The paper presents instantaneous selective short-circuit protection for the cabling of the underground part of a coal mine and central control algorithms as a Coal-Mine Power-Supply ACS Subsystem. In order to improve the reliability of electricity supply and reduce the mining equipment down-time, a dual channel relay protection and central control system is proposed as a subsystem of the coal-mine power-supply automated control system (PS ACS).

Design of dual DC motor control system based on DSP

Multi-motor control systems are widely used in actual production and life, such as lifting stages, robots, printing systems. This paper through serial communication between PC and DSP, dual DC motor control system consisting of PC as the host computer, DSP as the lower computer with synchronous PWM speed regulation, commutation and selection functions is designed. It sends digital control instructions with host computer serial debugger to lower computer, to instruct the motor to complete corresponding actions. The hardware and software design of the control system are given, and feasibility and validity of the control system are verified by experiments. The expected design goal is achieved.

Dynamic in-loop performance investigation and efficiency-cost analysis of dual heat sink thermal control system (DHS-TCS) with a sublimator for aerospace vehicles

Sublimator, as a highly efficient supplementary heat rejection device (SHReD), has been introduced to improve the performance of thermal control system (TCS). To evaluate the dynamic in-loop performance of sublimator, as well to reveal the potential optimal control strategies in particular scenarios, this paper proposes a sublimator-radiator dual heat sink thermal control system (DHS-TCS) configuration, of which the internal heat transfer mechanism model and the fast-prediction-oriented loop coupled model (FLCM) have been established. By these models, operation characteristics of sublimator, such as the allowed inlet temperature range of different sublimator area, heat rejection rate and expendable water consumption are discussed in details. Additionally, simulations of the dynamic in-loop performance of sublimator during on-orbit phase has also been conducted to compare temperature control efficiency (TCE) under different break condition temperature (BCT) settings. In order to evaluate the sublimator’s performance thoroughly, the efficiency-cost analysis between parameters of TCE and expendable water consumption has been simulated in the perspective of economy. Calculation results show that choosing a proper BCT, at which the efficiency-cost ratio achieves maximum and the water consumption remains at a local minimum, is of great importance for efficient utilization of sublimator. The FLCM and the efficiency-cost analysis model together provides the fast prediction capability of the sublimator’s performance for on-orbit control and decision making.

Dual Control High-rise Building for Robuster Earthquake Performance

A dual passive control system is proposed for high-rise buildings. Since the proposed system needs a substructure supporting the main building, it is usually used in high-rise residential apartment houses where a parking tower is used as the substructure. This new system consists of a base-isolation system and a building-connection system. While base-isolated buildings and interconnected buildings are effective for special earthquake ground motions, i.e. impulsive type and long-duration type, respectively, a building structure with such system as robust for both-type inputs has never been proposed and investigated in detail. Although some attempts have been conducted, realization of such systems has never been accomplished. In this paper, not only the theoretical background but also the actual installation in a real world is presented in detail. It is shown that the transfer function of the proposed dual building control system possesses lower values in a broader frequency range compared to the conventional building-connection system. This supports the high robustness of the proposed dual building system. It is also shown that the optimal connecting damper quantity providing a lower response of the main frame can be obtained by maximizing the area of energy transfer function which implies the energy absorption of the connecting dampers under an idealized white noise-like input.

Formulation and characterization of oxiconazole-loaded emulgel for topical application

Background: Oxiconazole nitrate is a new topical broad spectrum antifungal agent used to treat superficial fungal infections. It has a low aqueous solubility due to which different techniques are employed to enhance its bioavailability. Emulgel has emerged as one of the most interesting topical drug delivery system for hydrophobic drugs like Oxiconazole as it has dual release control systems i.e. emulsion and gel. Objective: In the present work an attempt was made to prepare Emulgel of Oxiconazole nitrate for enhancing its topical delivery. Materials and Methods: Emulgel formulations were characterized by various parameters like pH, viscosity, spreadability, extrudability, in vitro drug release. Skin irritation test on wistar rats and in vitro antifungal test on Candida albicans were performed. Results: Optimized formulation F5 showed 92.06% release at the end of 12 hrs. It showed no skin irritation and observed with maximum zone of inhibition when compared with marketed cream of Oxiconazole nitrate. Conclusion: The optimized emulgel formulation F5 showed better antifungal activity in comparison to the marketed formulation.

An increased resilient fault tolerant framework for navigation, guidance, control system with augmented resources

Onboard computers use redundant hardware for fault tolerance resulting in underutilisation of resources under fault free condition. This paper exploits the resource augmented model where task allocation based on task criticality ensures safe minimal functionality under permanent fault. An algorithm has been designed for real-time scheduling with fault tolerance and precedence constraints for hot standby dual redundant navigation, guidance, and control system. This algorithm is designed for recovery under permanent hardware fault in different case studies of single, double and triple units of different types (N, G, and C). It can tolerate permanent software failures, transient hardware and software failures occurring singly or as a combination in same type unit. Tolerating increased frequency of transient and software faults with same allowable safety margins and an increased flexibility in enhanced operational performance by different operational modes under fault and fault free condition without degrading safety margins are significant performance aspects of this design.

An increased resilient fault tolerant framework for navigation, guidance, control system with augmented resources

Onboard computers use redundant hardware for fault tolerance resulting in underutilisation of resources under fault free condition. This paper exploits the resource augmented model where task allocation based on task criticality ensures safe minimal functionality under permanent fault. An algorithm has been designed for real-time scheduling with fault tolerance and precedence constraints for hot standby dual redundant navigation, guidance, and control system. This algorithm is designed for recovery under permanent hardware fault in different case studies of single, double and triple units of different types (N, G, and C). It can tolerate permanent software failures, transient hardware and software failures occurring singly or as a combination in same type unit. Tolerating increased frequency of transient and software faults with same allowable safety margins and an increased flexibility in enhanced operational performance by different operational modes under fault and fault free condition without degrading safety margins are significant performance aspects of this design.

EMULGEL: A NEW APPROACH FOR ENHANCED TOPICAL DRUG DELIVERY

Emulgel is used to treat aches and pains caused by colds, headaches, muscle aches, backaches, arthritis and other conditions and injuries. The patient adherence to topical formulations is significant in relation to chronic skin diseases, like fungal infections, acne, psoriasis. Emulgel is one of the recent technology in NDDS used topically having characteristics of dual control release i.e. emulsion as well as gel. Emulgels have emerged as one of the most interesting topical delivery systems as it has dual release control system i.e. gel and emulsion. When gel and emulsion are used in combined form, the dosage form are referred as emulgel.

Robust sliding mode control with ESO for dual-control missile

This paper proposes a novel composite dual-control by combing the integral sliding mode control (ISMC) method based on the finite time convergence theory with extended state observer (ESO) for a tracking problem of a missile with tail fins and reaction-jet control system (RCS). First, the ISMC method based on finite time convergence is utilized to design the control law of tail fins and the pulse control of RCS for the dual-control system, ensuring the system with rapid response and high accuracy of tracking. Then, ESO is employed for the estimation of aerodynamic disturbances influenced by the airflow of thruster jets. With the characteristic of high accuracy estimation of ESO, the chattering free tracking performance of the attack angle command and the robustness of the control law are achieved. Meanwhile, the stability of the dual-control system is analyzed based on finite time convergence stability theorem and Lyapunov's theorem. Finally, numerical simulations demonstrate the effectiveness of the proposed design.

Dual DC Motor Speed Control Based on Two Independent Digital PWM Signals using PIC16F877A Microcontroller

<p>In this paper a dual open loop speed control system based on two independent PWM signals of small permanent magnet DC (PMDC) motors using PIC16F877A microcontroller (MCU) has been designed and implemented. The Capture/Compare/PWM (CCP) modules of the MCU are configured as PWM mode and the MCU is programmed using flowcode software package to generate two PWM signals with various duty cycles at the same frequency. A dual H-bridge channel chip SN754410 is used to drive the motors. The variation of PWM duty cycles is related directly to controlling the DC motors terminal voltage which directly proportional with speed of each motor. The complete PWM control system model has been simulated using proteus design suite software package. The development of hardware and software of the dual DC motor speed control system has been explained and clarified.</p>

Bionic tracking method by hand & eye-vergence visual servoing

Animals rotate their eyes to gaze at the target prey, enhancing the ability of measuring the distance to the target precisely for catching it. These animals, visual tracking includes the triangular eye-vergence control and their body’s motion control by visual servoing. The research aims to realize a bionic robot tracking performance, in which the body links moves together with eyes’ view orientation. This paper proposed a hand & eye-vergence dual control system which included two feedback loops: an outer loop for conventional visual servoing to direct a manipulator toward a target object and an inner loop for active motion control of binocular cameras to change the viewpoint along with the moving object to give an accurate and broad observation. This research also foused on how to compensate a fictional motion of the target seen by camera images in an eye-in-hand system, where the camera was fixed on the end-effector and moved together with the hand motion. A robust motion-feedforward (MFF) recognition method is proposed to compensate the fictional motion of the target based on the manipulator’s joint velocity, then the real motion of the target seen by camera images is extracted, which can improve the feedback image sensing unit to make the whole servoing system dynamically stable. The effectiveness of the proposed hand & eye-vergence visual servoing method is shown by tracking experiments using a 6-DoF robot manipulator and a 3-DoF binocular vision system.

Coupling effect and control strategies of the maglev dual-stage inertially stabilization system based on frequency-domain analysis

Maglev dual-stage inertially stabilization (MDIS) system is a newly proposed system which combines a conventional two-axis gimbal assembly and a 5-DOF (degree of freedom) magnetic bearing with vernier tilting capacity to perform dual-stage stabilization for the LOS of the suspended optical instrument. Compared with traditional dual-stage system, maglev dual-stage system exhibits different characteristics due to the negative position stiffness of the magnetic forces, which introduces additional coupling in the dual stage control system. In this paper, the coupling effect on the system performance is addressed based on frequency-domain analysis, including disturbance rejection, fine stage saturation and coarse stage structural resonance suppression. The difference between various control strategies is also discussed, including pile-up(PU), stabilize-follow (SF) and stabilize-compensate (SC). A number of principles for the design of a maglev dual stage system are proposed. A general process is also suggested, which leads to a cost-effective design striking a balance between high performance and complexity. At last, a simulation example is presented to illustrate the arguments in the paper.

Dual control system – A novel scaffolding architecture of an inducible regulatory device for the precise regulation of gene expression

Here, we present a novel scaffolding architecture of an inducible regulatory device. This dual control system is completely silent in the off stage and is coupled to the regulation of gene expression at both the transcriptional and translational levels. This system also functions as an AND gate. We demonstrated the effectiveness of the cumate-riboswitch dual control system for the control of pamamycin production in Streptomyces albus. Placing the cre recombinase gene under the control of this system permitted the construction of synthetic devices with non-volatile memory that sense the signal and respond by altering DNA at the chromosomal level, thereby producing changes that are heritable. In addition, we present a library of synthetic inducible promoters based on the previously described cumate switch. With only one inducer and different promoters, we demonstrate that simultaneous modulation of the expression of several genes to different levels in various operons is possible. Because all modules of the AND gates are functional in bacteria other than Streptomyces, we anticipate that these regulatory devices can be used to control gene expression in other Actinobacteria. The features described in this study make these systems promising tools for metabolic engineering and biotechnology in Actinobacteria.

Social conflict resolution regulated by two dorsal habenular subregions in zebrafish

When animals encounter conflict they initiate and escalate aggression to establish and maintain a social hierarchy. The neural mechanisms by which animals resolve fighting behaviors to determine such social hierarchies remain unknown. We identified two subregions of the dorsal habenula (dHb) in zebrafish that antagonistically regulate the outcome of conflict. The losing experience reduced neural transmission in the lateral subregion of dHb (dHbL)-dorsal/intermediate interpeduncular nucleus (d/iIPN) circuit. Silencing of the dHbL or medial subregion of dHb (dHbM) caused a stronger predisposition to lose or win a fight, respectively. These results demonstrate that the dHbL and dHbM comprise a dual control system for conflict resolution of social aggression.

MICRO850 AB SYNCHRONOUS CONTROL SYSTEM OF DOUBLE MOTORS BASED ON INTEGRAL SEPARATED PID ALGORITHM

Dual motor synchronization control is widely used. In this paper, the principle of variable frequency speed regulation of three-phase asynchronous motor is analyzed. And the control algorithm based on integral separation is established. By analyzing the vector control algorithm and acceleration curve, to establish the variable frequency control strategy. In order to analyze the motion curve of double motor and the ideal dynamic and static performance of the system, the construction of dual motor synchronization control system with Power Flex 525 frequency converter and AB Micro850 PLC is needed, and thus we can achieve the goal of high efficiency and good performance of dual motor synchronization control system.

Response Characteristic of the Dual-frame Passive Control System with the Natural Period Difference between the Strength Resistant Core and Frame Structure

In this study, shaking table test has been carried out for the dual frame passive control system for seismic performance verification of the proposed system. The proposed system was separated into two independent frameworks that are strength resistant core and frame structure by connecting to the damper. Moreover, the seismic performance improvement of the proposed system has been verified by comparing and analyzing the experimental results of the proposed system with an existing core system. As a result of the shaking table test, acceleration and displacement responses of dual-frame vibration control system are decreased than those of the existing strength resistant type core system. In the case of the core system, while the damage was concentrated on the column of first floor, the damage of the dual system was dispersed in each layer. The damage also was concentrated on the damper, almost no damage occurs to the structural members. It has been emphasized that installed dampers in the proposed dual system reduce the input energy of whole structure by absorbing seismic input energy, which leads overall system damage to be reduced.

Glucagon sensitivity and clearance in type 1 diabetes: insights from in vivo and in silico experiments.

Glucagon use in artificial pancreas for type 1 diabetes (T1D) is being explored for prevention and rescue from hypoglycemia. However, the relationship between glucagon stimulation of endogenous glucose production (EGP) viz., hepatic glucagon sensitivity, and prevailing glucose concentrations has not been examined. To test the hypothesis that glucagon sensitivity is increased at hypoglycemia vs. euglycemia, we studied 29 subjects with T1D randomized to a hypoglycemia or euglycemia clamp. Each subject was studied at three glucagon doses at euglycemia or hypoglycemia, with EGP measured by isotope dilution technique. The peak EGP increments and the integrated EGP response increased with increasing glucagon dose during euglycemia and hypoglycemia. However, the difference in dose response based on glycemia was not significant despite higher catecholamine concentrations in the hypoglycemia group. Knowledge of glucagon's effects on EGP was used to develop an in silico glucagon action model. The model-derived output fitted the obtained data at both euglycemia and hypoglycemia for all glucagon doses tested. Glucagon clearance did not differ between glucagon doses studied in both groups. Therefore, the glucagon controller of a dual hormone control system may not need to adjust glucagon sensitivity, and hence glucagon dosing, based on glucose concentrations during euglycemia and hypoglycemia.

Control of the reproductive axis: Balancing act between stimulatory and inhibitory input

As for most vertebrates, reproduction in poultry is controlled by an integrated axis [the hypothalamo-pituitary-gonadal (HPG) axis]. External and internal cues are integrated at the level of the hypothalamus to initiate gonadal recruitment and control the subsequent reproductive cycle. Until recently, it was believed that the HPG was exclusively under stimulatory control from hypothalamic gonadotropin releasing hormone (GnRH). However in 2000, the discovery of gonadotropin inhibitory hormone (GnIH), an inhibitory peptide, changed this dogma. Since then, evidence accumulated to confirm that in fact the HPG is under a dual control system with a stimulatory and an inhibitory branch. In this paper, we review the organization of this dual control system, the mechanisms controlling the synthesis and release of GnRH and GnIH, and the possible integration and interactions between the two branches to regulate pituitary gonadotropes’ function. Furthermore, as light perception and photoperiod are the primary cues utilized by the poultry industry in controlled environments, special consideration was given to potential practical applications.

Static Decouplers with P-PI Dual Loop Controllers for Unstable System

The applicability of static decoupler followed by tuning of diagonal proportional integral controllers for unstable multivariable process is studied. The need of static decouplers for an unstable multivariable system where the conventional decouplers becomes unstable is brought about by using three examples of a two-input two-output processes. Further, dual loop controllers are tuned for the approximated decoupled system. Use of P-PI (Proportional – Proportional and Integral) dual loop control system reduces the overshoot significantly.