Manual Control Mode Research Articles

Dosimetric characterization and organ dose assessment in digital breast tomosynthesis: Measurements and Monte Carlo simulations using voxel phantoms.

Due to its capability to more accurately detect deep lesions inside the breast by removing the effect of overlying anatomy, digital breast tomosynthesis (DBT) has the potential to replace the standard mammography technique in clinical screening exams. However, the European Guidelines for DBT dosimetry are still a work in progress and there are little data available on organ doses other than to the breast. It is, therefore, of great importance to assess the dosimetric performance of DBT with respect to the one obtained with standard digital mammography (DM) systems. The aim of this work is twofold: (i) to study the dosimetric properties of a combined DBT/DM system (MAMMOMAT Inspiration Siemens(®)) for a tungsten/rhodium (W/Rh) anode/filter combination and (ii) to evaluate organs doses during a DBT examination. For the first task, measurements were performed in manual and automatic exposure control (AEC) modes, using two homogeneous breast phantoms: a PMMA slab phantom and a 4 cm thick breast-shaped rigid phantom, with 50% of glandular tissue in its composition. Monte Carlo (MC) simulations were performed using Monte Carlo N-Particle eXtended v.2.7.0. A MC model was implemented to mimic DM and DBT acquisitions for a wide range of x-ray spectra (24 -34 kV). This was used to calculate mean glandular dose (MGD) and to compute series of backscatter factors (BSFs) that could be inserted into the DBT dosimetric formalism proposed by Dance et al. Regarding the second aim of the study, the implemented MC model of the clinical equipment, together with a female voxel phantom ("Laura"), was used to calculate organ doses considering a typical DBT acquisition. Results were compared with a standard two-view mammography craniocaudal (CC) acquisition. Considering the AEC mode, the acquisition of a single CC view results in a MGD ranging from 0.53 ± 0.07 mGy to 2.41 ± 0.31 mGy in DM mode and from 0.77 ± 0.11 mGy to 2.28 ± 0.32 mGy in DBT mode. Regarding the BSF, the results achieved may lead to a MGD correction of about 6%, contributing to the improvement of the current guidelines used in these applications. Finally, considering the MC results obtained for the organ dose study, the radiation doses found for the tissues of the body other than the breast were in the range of tens of μSv, and are in part comparable to the ones obtained in standard DM. Nevertheless, in a single DBT examination, some organs (such as lung and thyroid) receive higher doses (of about 9% and 21%, respectively) with respect to the CC DM acquisition. Taking into account an average breast with a thickness of 4.5 cm, the MGDs for DM and DBT acquisitions were below the achievable value (2.0 mGy) defined by the European protocol. Additionally, in the case of a fusion imaging study (DM + DBT), the MGD for a 4.5 cm thick breast is of the order of 1.88 ± 0.36 mGy. Finally, organ dose evaluations underline the need to improve awareness concerning dose estimation of DBT exams for some organs, especially when radiation risk is assessed by using the effective dose.

Modelling of thermal power plant for the needs of Q-V characteristic control on HV bus bars

In this paper, a mathematical model of the thermal power plants TENT A and TENT B, developed for voltage and reactive power control simulation purposes, is presented. The model is developed using the Simulink/Matlab program platform. All important elements, such as synchronous generator, step-up transformer, turbine and governor, excitation system, automatic voltage regulator (ARN) and the network, connected to the power plant's bus bars, are modelled with the complexity level required for studying the problems of interest. In the first part, a review of the hierarchical voltage control in the system is given, because the coordinated reactive power regulator (GRRS) has to be embedded in future processes of voltage control automatisation on higher levels and 'smart' control in the power system. For the needs of studying the HV bus bars voltage control, as well as reactive power allocation within the power plant in manual and automatic control mode, a series of simulations was performed. For verification purposes, the simulation results are compared to the on-site measurements. An excellent match of simulated and recorded results is achieved.

Assessment of Alternative Manual Control Methods for Small Unmanned Aerial Vehicles

This paper is a summary of experiments to access alternative methods to control a small (<25kg)1 Unmanned Aerial Vehicle (UAV) in manual mode. While it is true that the majority of the UAV airborne activities will be in autonomous mode (i.e. using an autopilot) this may not always be the case during takeoffs and landings, or if there is a failure of the autopilot. The requirement for a manual control mode for all flight stages remains in proposed UAV regulations currently being defined both in Canada and the U.S. The question then becomes “If we have to take manual control of the UAV, what is the best method?” The research summarized in this paper is an attempt this question.

The Design of Rudder System Simulation Device

This paper designs a ship rudder system simulation device in order to serve the research of ship control better with the proportion of a real marine hydraulic rudder system, which can complete closed-loop experiments in the lab with the steering system. The rudder system simulation device mainly includes two parts, electric control system which uses PLC as core control unit, hydraulic system, and it can achieve both manual and automatic operation control mode.

Integrated vision-based system for efficient, semi-automated control of a robotic manipulator

Purpose – The purpose of this paper is to develop an integrated, computer vision-based system to operate a commercial wheelchair-mounted robotic manipulator (WMRM). In addition, a gesture recognition interface system was developed specially for individuals with upper-level spinal cord injuries including object tracking and face recognition to function as an efficient, hands-free WMRM controller. Design/methodology/approach – Two Kinect® cameras were used synergistically to perform a variety of simple object retrieval tasks. One camera was used to interpret the hand gestures and locate the operator's face for object positioning, and then send those as commands to control the WMRM. The other sensor was used to automatically recognize different daily living objects selected by the subjects. An object recognition module employing the Speeded Up Robust Features algorithm was implemented and recognition results were sent as a commands for “coarse positioning” of the robotic arm near the selected object. Automatic face detection was provided as a shortcut enabling the positing of the objects close by the subject's face. Findings – The gesture recognition interface incorporated hand detection, tracking and recognition algorithms, and yielded a recognition accuracy of 97.5 percent for an eight-gesture lexicon. Tasks’ completion time were conducted to compare manual (gestures only) and semi-manual (gestures, automatic face detection, and object recognition) WMRM control modes. The use of automatic face and object detection significantly reduced the completion times for retrieving a variety of daily living objects. Originality/value – Integration of three computer vision modules were used to construct an effective and hand-free interface for individuals with upper-limb mobility impairments to control a WMRM.

Study on Flue Gas Desulfurization Process Control System Based on Coupling Decoupling Control

The coupling decoupling control system was presented to realize the requirement of the flue gas desulfurization (FGD), to solve the multivariable control problem in this process control system. The FGD experiment control system was designed, the spray flow was controlled by manual and automatic control mode. After the process control flow and the coupling decoupling control principle were studied, the feed-forward compensation control method was simulated. Results show that the decoupling control method could solve the multivariable control problem, with a good anti-interference capacity, meeting the requirement of FGD process control.

Greenhouse Monitoring and Control System Based on Zigbee

A greenhouse monitoring and control system based on Zigbee networks was developed. This system consists of greenhouse data acquisition controller and greenhouse remote monitoring and control software. The system could monitor temperature and humidity, soil water content and concentration of carbon dioxide in greenhouse and could save these greenhouse data to database. Greenhouse acquisition controller had two kinds of control modes, including local manual control mode and remote wireless control mode in monitoring center. Greenhouse remote monitoring and control software can collect, display and record the collected data, also can control greenhouse environment. According to the current indoor temperature, the target temperature and the offset temperature, PID control method is used for temperature control in greenhouse. The system is implemented using low power wireless components, and easy to be installed. A good wireless solution is provided by this system for centralized management of the greenhouse group.

Pilot Performance, Workload, and Situation Awareness During Lunar Landing Mode Transitions

Aircraft and spacecraft pilots frequently change their level of supervisory control between full autopilot and other modes, providing varying levels of manual control. Therefore, multimodal systems must transition “gracefully,” meaning without unsafe decreases in flight performance or unacceptable changes in workload or situation awareness. Thirteen subjects flew a fixed base simulation of the NASA Constellation Program Altair lunar lander that transitioned from full autopilot to one of three flight-director-guided rate-command attitude hold manual control modes. After training, each subject flew 24 approaches, half of which included a landing point redesignation at the time of the mode transition requiring the pilot to null additional guidance errors. Bedford subjective workload and two-choice embedded secondary task response times were used to quantify temporal changes in mental workload. Situation awareness transients were detected by analysis of a tertiary task, verbal callouts of altitude, fuel, and terrain hazards. Graceful transitions were particularly difficult because Altair’s large inertia made the plant dynamics relatively sluggish. Transitions to manual control increased subjective and objective workloads and decreased callout accuracy in proportion to the number of flight control axes being manually commanded.

An Intelligent Wheelchair Control System Based on F28335

According to the idea of the modular design, an intelligent wheelchair control system based on F28335 is designed. This paper introduces this system, including the whole structure, hardware composition and corresponding software design. Control mode of the intelligent wheelchair is divided into manual control and automatic control mode. Using the operating lever, brain wave control signal and hands, users can let the intelligent wheelchair go forward, go backward, turn left, turn right, accelerate and stop. This control system has a lot of advantages, for example, simple structure and easy to expand functions and so on.

Evaluation of a Completely Robotized Neurosurgical Operating Microscope

Operating microscopes are essential for most neurosurgical procedures. Modern robot-assisted controls offer new possibilities, combining the advantages of conventional and automated systems. We evaluated the prototype of a completely robotized operating microscope with an integrated optical coherence tomography module. A standard operating microscope was fitted with motors and control instruments, with the manual control mode and balance preserved. In the robot mode, the microscope was steered by a remote control that could be fixed to a surgical instrument. External encoders and accelerometers tracked microscope movements. The microscope was additionally fitted with an optical coherence tomography-scanning module. The robotized microscope was tested on model systems. It could be freely positioned, without forcing the surgeon to take the hands from the instruments or avert the eyes from the oculars. Positioning error was about 1 mm, and vibration faded in 1 second. Tracking of microscope movements, combined with an autofocus function, allowed determination of the focus position within the 3-dimensional space. This constituted a second loop of navigation independent from conventional infrared reflector-based techniques. In the robot mode, automated optical coherence tomography scanning of large surface areas was feasible. The prototype of a robotized optical coherence tomography-integrated operating microscope combines the advantages of a conventional manually controlled operating microscope with a remote-controlled positioning aid and a self-navigating microscope system that performs automated positioning tasks such as surface scans. This demonstrates that, in the future, operating microscopes may be used to acquire intraoperative spatial data, volume changes, and structural data of brain or brain tumor tissue.

Fuzzy-Logic Modeling of a Rolling Unmanned Vehicle in Antarctica Wind Shear

of wind shear are investigated using the recorded test data during a flight from the Pegasus white ice runway in Antarctica. The main purpose of this paper is to determine the reasons and characteristics of roll oscillations for improvement of autopilot design and ground operator training. The Meridian flight test is conducted with the necessaryrangeconstraint, which precludes steadylevel flight.The measured orestimated data,such as theangle of attack and sideslip angle, are filtered through a nonlinear compatibility analysis. The estimated aerodynamic coefficients are modeled as implicit functions of filtered flight variables in a concept of aerodynamic model identification, instead of parameter identification. A model identification method called fuzzy-logic modeling is used to set up the aerodynamic models without assuming the functional relations. The aircraft’s oscillatory stability and control derivatives are found to be significantly impacted by the environmental disturbances. The exhibited highly oscillatory motion in the manual-control mode is analyzed and identified as the pilot-induced oscillation with a new energy method. It is shown that the pilot-induced oscillation is identified as the motion when the motion energy is increasedbythecontrolinput.Intheautopilot flight,themotionisdeterminedtobewingrock,whichisexcitedbythe pilot-induced oscillation in the manual mode and sustained by the interaction between the wing wake and the V tail.

The Design of the Small Automatic Batching Machine Control System

The paper describes a small batching machine control system that takes chip C8051F040 as the core controller. The system that has automatic control and manual control modes can complete the high-precision automatic weighing of few powder and granular material. This article describes the composition of the control system and the major design of hardware, and provides more detailed software program scheme.

Design and Implementation of Automatic Drainage in Coal Mine

Drainage system is one of the important sub-systems of coal mine integrative control platform[1], and is used to guarantee the safety of mining and auxiliary transportation under the ground. The functions of drainage system are defined, the network framework is designed, the start and stop procedures of the pump engine under the manual control mode and automatic control mode are described, and the determining methods based on liquid level to control several pumps in automatic mode are analyzed. By using Simense PLC module, power source module, digital module, analog module and touch screen hardware, the drainage system control platform is set up, which is connected to the control computer on the ground by using Simense communication module and industrial ring Ethernet[4], and achieved the purpose of remote control.

Stabilising agent design for the control of interconnected systems

This article presents a new control design strategy for stabilising large-scale interconnected systems operating in semi-automatic control modes. The large-scale system is modelled by subsystems connected to each other in an arbitrary configuration. Each subsystem is regulated by a dedicated multivariable controller that also allows for a manual control mode. The notion of asymptotically positive realness constraint (APRC) is introduced and applied for deriving the interconnection stabilisability condition in the time domain. The interactions between subsystems are taken into consideration in the stability condition. The APRC is subsequently employed in the so-called stabilising agent to accommodate the closed-loop control and man-in-the-loop coexistence. The multipliers of the APRC quadratic supply rate are updated on-the-fly to ensure that the constraint satisfaction of stabilising agents is recursively feasible. The stabilising agents are developed independently from the control law under the same auspice controller. Due to this independence, operational errors from the manual control adjustments, that may destabilise the control systems, can be avoided. The decentralised agents render stabilising bounds for the manipulated variables in the automatic control mode, and at the same time, provide warning signals and manipulation guidance for the operators to prevent possible plant-wide destabilisation in the manual control mode. Our main results are illustrated through numerical simulations for an industrial modular system.

Development of a control system for a multipurpose road repairing machine

In this paper an automatic control system for a multipurpose road pavement repairing machine (ROADMOTO) is introduced. The goal is to achieve cost savings and better work quality by means of automation. Before the actual repair work a GPR (Ground Penetrating Radar), a profilometer or laser scanning techniques are used for collecting information about the road. During the design phase a repair design file is created. The ROADMOTO machine is equipped with a GPS positioning unit and the repair design file can be used for automatic control of road repairing operations. The control system also offers a manual control mode as well as automatic height and slope control modes. This ensures flexibility, because the user can choose the control mode that best suits the situation. The process from data collection and design to automatic machine control is presented as well as the developed prototype system and results of the first tests.

Towards Autonomous User Privacy Control

In this article, we propose a consent decision-making mechanism, ShEM, which allows users to exert automatic and manual control over their private information. An enhanced fuzzy logic approach was developed for the automatic decision-making process. The proposed mechanism has been prototyped and integrated in a UMTS location-based services testbed on a university campus. Users have experienced the services in real time. A survey of users’ responses on the privacy functionality has been carried out and analyzed as well. Users’ response on the privacy functionality was positive. Additionally, results obtained showed that a combination of both manual and automatic privacy control modes in one approa

Situation awareness implications of adaptive automation for information processing in an air traffic control-related task

The objective of this research was to assess the effectiveness of adaptive automation (AA) for supporting information processing (IP) in a complex, dynamic control task by defining a measure of situation awareness (SA) sensitive to differences in the forms of automation. The task was an air traffic control (ATC)-related simulation and was developed to present four different modes of automation of IP functions, including information acquisition, information analysis, decision making and action implementation automation, as well as a completely manual control mode. A total of 16 participants were recruited for a pilot study and primary experiment. The pilot assessed the sensitivity and reliability of the Situation Awareness Global Assessment Technique (SAGAT) for describing AA support of the IP functions. Half of the participants were used in the primary experiment, which refined the SA measure and described the implications of AA for IP on SA using the ATC-like simulation. Participants were exposed to all forms of automation and manual control. AA conditions matched operator workload states to dynamic control allocations in the primary task. The pilot did not reveal significant differences in SA among the various AA conditions. In the primary experiment, participant recall of aircraft was cued and relevance weights were assigned to aircraft at the time of simulation freezes. The modified measure of SA revealed operator perception and Total SA to improve when automation was applied to the information acquisition function. In both experiments, performance in the ATC-related task simulation was significantly superior when automation was applied to information acquisition and action implementation (sensory and motor processing), as compared to automation of cognitive functions, specifically information analysis. The primary experiment revealed information analysis and decision-making automation to cause higher workload, attributable to visual demands of displays. Industry relevance The results of this research may serve as a general guide for the design of adaptive automation functionality in the aviation industry, particularly for information processing support in air traffic control tasks.

Comparison of beam‐hardening and K‐edge filters for imaging barium and iodine during fluoroscopy

This study investigated the dose reduction performance of several beam-hardening and K-edge filter materials for the imaging of barium or iodine during fluoroscopy. A computer model was developed to simulate the effect of added filtration on entrance exposure rate (Xp), integral dose rate (Di), contrast (C), signal to noise ratio (SNR), imaging performance per dose (SNR2/Di), and tube load. The model incorporated the response characteristics, in both manual and automatic control modes of operation, of fluoroscopic systems to increasing or decreasing x-ray intensity at the input of the image intensifier. Input parameters to the computer model included choice of filter material and thickness, a barium or iodine test object, tube potential, phantom thickness, a CsI input phosphor, and a set of algorithms for controlling the fluoroscopic system. In all cases, the performance of systems with added filtration was judged with respect to a reference system operating under comparable conditions. In general, either beam-hardening or K-edge filters provided a significant reduction in entrance exposure and integral dose rates, but with an attendant increase in tube load. For a fluoroscopic system constrained to follow a representative automatic brightness control algorithm, added filtration provided a reduction in entrance exposure and integral dose rates for all phantom or uniformly distributed barium thickness. However, the imaging performance per dose, in some cases, decreased rapidly and was less than that of the reference system at large thicknesses. Only as change in the algorithm controlling the kVcp and mA operating points on the fluoroscopic system provided an imaging performance per dose greater than the reference system's at large thicknesses. The practical implementation of adding filtration to fluoroscopic systems is most simply accomplished with beam-hardening filters rather than K-edge filters. However, the systems with K-edge added filtration can provide slightly better performance when used over a limited range of phantom thicknesses such as the range normally associated with pediatric patients.

Telerobotic visual servoing

This paper addresses the problem of integrating the human operator with autonomous robotic visual tracking and servoing modules. A CCD camera is mounted on the end-effector of a robot and the task is to servo around a static or moving rigid target. In manual control mode, the human operator, with the help of a joystick and a monitor, commands robot motions in order to compensate for tracking errors. In shared control mode, the human operator and the autonomous visual tracking modules command motion along orthogonal sets of degrees of freedom. In autonomous control mode, the autonomous visual tracking modules are in full control of the servoing functions. Finally, in traded control mode, the control can be transferred from the autonomous visual modules to the human operator and vice versa. This paper presents an experimental setup where all these different schemes have been tested. Experimental results of all modes of operation are presented and the related issues are discussed. In certain degrees of freedom (DOF) the autonomous modules perform better than the human operator. On the other hand, the human operator can compensate fast for failures in tracking while the autonomous modules fail. Their failure is due to difficulties in encoding an efficient contingency plan.

European rendezvous and docking system

This paper first describes the major design drivers and the key features of the European RendezVous and Docking System Concept. Stemming from technology activities led by the European Space Agency (ESA) with European Industry and National Space Agencies since the beginning of the eighties, the concept has been developed and integrated in the frame of an ESA RVD System Pre-Development Programme initiated at ESTEC in 1989, with MATRA as main contractor. The objective is to verify the overall concept and the main elements within a RVD Proof of Concept Programme in order to provide an early proof of validity to the user projects, the first of which will be the Hermes manned space shuttle. The selected mission scenarii, the RVD functions addressed and the overall system architecture are described. The results of supporting safety, performance and operations analyses are presented. The paper further presents the verification objectives and the major results obtained in the RVD System Pre-Development Programme. This verification approach involves hardware breadboards, software prototypes, development of test facilities in four main development areas: test of RV sensors on a 6 d.o.f. kinematic test facility, test of a docking mechanism front-end mock-up on the docking dynamics test facility, closed-loop test of a prototype RV control software, test of man-in-the-loop concept involving both supervisory control and manual control modes.