Realistic Simulation Environment Research Articles

Evaluation Framework for Dynamic Vehicle Routing Strategies Under Real-Time Information

Dynamic vehicle dispatching and routing strategies are important aspects of commercial vehicle operations applications of intelligent transportation systems technologies. One possible operational benefit of real-time information is the ability to reroute commercial vehicles efficiently according to current traffic conditions. A dynamic evaluation framework in which dispatching and routing strategies for individual vehicles can be tested in a realistic traffic simulation environment is developed. The simulation-assignment model, DYNASMART, is applied to evaluate such strategies in a traffic network. Numerical experiments conducted in the Taichung network are presented to investigate dynamic vehicle dispatching and routing strategies under real-time information supply strategies and to assess the effectiveness of such strategies in a dynamic perspective.

Crisis resource management among strangers: principles of organizing a multidisciplinary group for crisis resource management

Patient safety depends on the skills, vigilance, and judgment of trained individuals working as members of a clinical team that includes anesthesiologists, surgeons, nurses, and technicians. Now, as never before, safe outcome depends both on better knowledge and better management. This requires organization of caregivers, who may be strangers from diverse disciplines, into teams. One can drill an individual to work safely alone. One can rehearse a series of scenarios with small groups (who regularly work together) to improve performance. But what does one do with an unrehearsed group, called together in an emergency from several different disciplines, usually including Anesthesia. These people may not know each other, their roles, their special skills, and may even be hazy about each other’s goals. Rapid organization of such an ad hoc team becomes a critical priority where patient safety is at stake. The way by which such an ad hoc team from several disciplines can rapidly be helped to function effectively together is by teaching all the “strangers” the principles of Crisis Resource Management. These principles are not as well-presented in a written text or lecture format, as one cannot introduce the sense of urgency that emotionally charges and changes the impact. We believe the best teacher is experience gained in a realistic simulated environment using a model driven, full human simulator. This simulated environment is safe for both patient and trainee.

High speed driving: Police use of lethal force during simulated incidents

Purpose. The effects of high speed driving and field independence on police officers'physiological arousal, emotion and shooting behaviour were investigated within two operationally realistic simulated firearms environments. Based upon Zillmann's (1971) excitation transfer theory it was hypothesized that officers would misattribute theirfeelings of arousal caused by high speed driving, attributing these feelings to the suspect, resulting in increased feelings of irritation towards the suspect, and thus have ahigher probability of an inappropriate discharge of their weapon. In addition, research in the area of field dependence‐ independence has revealed that field dependent people are more easily distracted than field independent people (Feij, 1976). Therefore, it was predicted that high speed driving would lead to an increase in self‐rated willingness to shoot the suspect and actual shooting, especially in police officers who are field dependent. Methods. Twenty‐nine pairs of Authorised Firearms Officers were briefed on an ‘incident’ they would be asked to attend. Officers were instructed to drive at either patrol or high speed. On arrival at the simulated incident, officers were asked to respond to one of two scenarios: one where the officer would be justified in shooting the suspect, or one where it would be difficult for the officer to justify having shot the suspect. Results and Conclusions. Results revealed that driving at high speed did indeed increase officers' objective and subjective feelings of arousal, feelings of irritation towards the suspect, and reduced officers self‐rated willingness to shoot the suspect. Field dependent officers reported feeling significantly more willing to shoot the suspect when it was legally justifiable. Speed of driving, role in the car (driver/passenger), and field independence had no significant main effect on police officers' shooting behaviour either in the scenario where officers were justified to shoot the suspector in the scenario where it was difficult to justify having shot the suspect.

SIMART: A CACSD Package for Advanced Control

Abstract A general purpose computer aided control system design package called SIMART has been developed from the available control theory. It can be used as a learning basis for advanced control as well as a control engineering framework. SIMART has already been successfully used in realistic simulation environments as well as real time experiments involving several laboratory pilots that have been interfaced with PC computer using IO cards as Lab Master, Alliance. RTI and PC Lab. An industrial interface of SIMART has been recently developed from a programmable logical controller “PMX serie 7” of the Schneider Automation company. An application is reported to demonstrate the feasibility of the underlying advanced control approach of SIMART.

Advanced Control Using a Programmable Logical Controller

Abstract A general purpose computer aided control system design package called SIMART has been developed from the available control theory. It can be used as a learning basis for advanced control and as a control engineering framework and it has already been successfully used in realistic simulation environments as well as real time experiments involving several laboratory pilots that have been interfaced with PC computer through using 10 cards, namely Lab Master, Alliance, RTI and PC Lab. An industrial interface of SIMART has been recently developed from a programmable logical controller “PMX serie 7 of the Schneider Automation company. This is our modest contribution to the transfer of advanced control in the real world life which we aim to present in this paper. An application is reported to demonstrate the feasibility of our advanced control approach.

Comparison of low-earth-orbit satellite attitude controllers submitted to controllability constraints

A rule-based fuzzy controller is presented and compared with an adaptive MIMO LQR controller in a low-Earth-orbit small satellite attitude control system. The attitude is passively gravity gradient stabilized and actively three-axis magnetorquer controlled. This method insures an Earth-pointing satellite making use of a nondepletable and nonmechanical means of control. A realistic simulation environment, using a nonlinear satellite dynamic model with linear attitude estimators plus sensor measurement noise and external disturbance torques, was used to evaluate the different control techniques.

An AGC implementation for system islanding and restoration conditions

An island AGC function has been implemented in a large-scale power system, Virginia Power Company (VP), to assist in system emergency and restoration situations. It is the first time that the conventional AGC function has been enhanced to be utilized, rather than to be suspended, under such circumstances. The island AGC function is designed to be implemented in both the real-time and the dispatcher training simulator (DTS) environments. The latter provides a realistic closed-loop simulation environment that mimics the real system behavior, offering an excellent opportunity for operators to be well-trained, aware and prepared for abnormal situations. This implementation has been tested on the VP system model, which consists of 4400 buses and 775 generators. It has successfully completed custom factory tests, and it is the user's opinion that the island AGC will provide a valuable additional capability for use during system restoration. >

Noncontact force microscopy in liquids

Force microscopy in liquids offers many advantages including the mitigation of capillary forces and the simulation of real environments for biological and technological processes. Noncontact force microscopy in liquids adds the advantage of probing electrical and magnetic fields above surfaces. Here we demonstrate magnetic force imaging of recorded bits on a computer hard disk in air and in liquid. A method of noncontact force microscopy (patent pending, Digital Instruments) is used in which the tip is first scanned in contact to image topography and then rescanned above the surface to image long-range forces.

A New Nonlinear Adaptive Autopilot for Ships

Abstract An autopilot design project is presented. The design is based on a nonlinear ship model. This nonlinear ship model explains the results obtained from the standard ship manoeuvering tests. Controller parameters are computed as a function of the linearized ship model parameters. The autopilot adapts to changing dynamics by using gain scheduling. A nonlinear modified second order filter is used to filter the wave induced movements from the measurements. The autopilot is tested in a realistic simulation environment.

Simulator motion-drive algorithms - A designer's perspective

Changes in the design of software algorithms for generating physical motion in flight simulators have typically been put forward on the grounds of improved motion cueing. Little attention has been paid to more practical criteria such as computational cost, ease of adjustment, or evaluation by experienced pilots in a realistic simulation environment. A comparison of three of the algorithms most commonly found in the literature has been performed: classical washout, optimal control, and coordinated adaptive. This consisted of pilot evaluations of these algorithms implemented on a six-degree-of-freedom flight simulator simulating a large transport aircraft during low-altitude flight and ground maneuvering. This paper presents the results of that study from the designer's viewpoint. In it, we contend that, with enough effort, most algorithms can be massaged to perform reasonably well, and that a more important consideration is the ease with which a given algorithm can be brought to high performance levels. If this criterion is used, it appears that the classical algorithm is a good starting point, and that the benefits of an adaptive algorithm can be added gradually to obtain the advantages conferred by nonlinear filtering and intelligent cost functions.