Roger Lew

A prototyping environment for research on human-machine interfaces in process control use of Microsoft WPF for microworld and distributed control system development

Operators of critical processes, such as nuclear power production, must contend with highly complex systems, procedures, and regulations. Developing human-machine interfaces (HMIs) that better support operators is a high priority for ensuring the safe and reliable operation of critical processes. Human factors engineering (HFE) provides a rich and mature set of tools for evaluating the performance of HMIs, but the set of tools for developing and designing HMIs is still in its infancy. Here we propose that Microsoft Windows Presentation Foundation (WPF) is well suited for many roles in the research and development of HMIs for process control.

Early-Stage Design and Evaluation for Nuclear Power Plant Control Room Upgrades

As control rooms are modernized with new digital systems at nuclear power plants, it is necessary to evaluate operator performance with these systems as part of a verification and validation process. While there is regulatory and industry guidance for some modernization activities, there are no well defined standard processes or predefined metrics available for assessing what is satisfactory operator interaction with new systems, especially during the early design stages. This paper proposes a framework defining the design process and metrics for evaluating human system interfaces as part of control room modernization. The process and metrics are generalizable to other applications and serve as a guiding template for utilities undertaking their own control room modernization activities.

A Microworld Simulator for Process Control Research and Training

We introduce and will demonstrate a new software tool for creating simulations of simplified process control tasks—what Vincente (2000) termed microworlds—for research and training applications. This tool builds on previous software tools, such as the synthetic task environment DURESS, but provides more flexibility in simulation design, a more realistic physics model, and additional components for representing complex processes, such as auditory and visual alarms for nuclear power plants. Further, our microworld simulation tool can be used for a variety of tasks, from flexibly specifying a synthetic environment for research on a desktop computer to scaling up to large format touch displays with realistic controls typical of high-fidelity process control simulators. Potential applications of the microworld simulator include research on the cognitive engineering of human-machine interfaces used in process control, training of process control operators and other personnel, and rapid prototyping and testing of process controls and displays.

Fault Diagnosis with Multi-State Alarms in a Nuclear Power Control Simulator

This research addresses how alarm systems can increase operator performance within nuclear power plant operations. The experiment examined the effect of two types of alarm systems (two-state and three-state alarms) on alarm compliance and diagnosis for two types of faults differing in complexity. We hypothesized three-state alarms would improve performance in alarm recognition and fault diagnoses over that of two-state alarms. We used sensitivity and criterion based on Signal Detection Theory to measure performance. We further hypothesized that operator trust would be highest when using three-state alarms. The findings from this research showed participants performed better and had more trust in three-state alarms compared to two-state alarms. Furthermore, these findings have significant theoretical implications and practical applications as they apply to improving the efficiency and effectiveness of nuclear power plant operations.

An Implementation of a Graded Deceleration Display in Brake Light Warning Systems

The purpose of this research is to assess the effectiveness of the Graded Deceleration Display (GDD) that is designed to replace the rear center high mounted stop lamp on automobiles. Licensed drivers were treated in simulation to both a standard brake light displays (binary) and the GDD display while the lead vehicle (LV) varied its deceleration magnitude and ramping behavior. Results entailed that the graded system produced more accurate behavioral responses during deceleration, fewer collisions, and a safer following distance than the binary system. Future research should be concerned with solidifying this framework so that it can be used to improve safety, effectiveness, and efficiency for vehicle transportation.

Assessing Mental Workload from Skin Conductance and Pupillometry using Wavelets and Genetic Programming

An essential component of augmented cognition (AC) is developing robust methods of extracting reliable and meaningful information from physiological measures in real-time. To evaluate the potential of skin conductance (SC) and pupil diameter (PD) measures, we utilized a dual-axis pursuit tracking task where the control mappings repeatedly and abruptly rotated 90° throughout the trials to provide an immediate and obvious challenge to proper system control. Using these data, a model-building technique novel to these measures, genetic programming (GP) with scaled symbolic regression and Age Layered Populations (ALPS), was compared to traditional linear discriminant analysis (LDA) for predicting tracking error and control-mapping state. When compared with traditional linear modeling approaches, symbolic regression better predicted both tracking error and control mapping state. Furthermore, the estimates obtained from symbolic regression were less noisy and more robust.

Nuclear Reactor Crew Evaluation of a Computerized Operator Support System HMI for Chemical and Volume Control System.

A Computerized Operator Support System (COSS) functional prototype was developed as an assistive technology for operators. The COSS was implemented as a hybrid control board for the Chemical Volume Control System (CVCS) of a three loop Combustion Engineering pressurized water reactor and implemented full-scope, full-scale, glass top control room simulator. The hybrid control board simulated a modernized control room with both analog and digital instrumentation and control. The digital portions consisted of large digital overview and smaller touch displays, while the analog portion consisted primarily of safety indicators and controls. The glass top nature of the simulator allowed the COSS configuration to be compared to the existing fully analog configuration. A cooperative research and development agreement with a major US utility allowed for two separate licensed three-person crews of commercial reactor operators to evaluate the COSS. The evaluation revealed stylistic issues, operation insights, and design considerations that will guide control room modernization efforts and influence next generation control systems and Human Machine Interfaces.

Rancor: A Gamified Microworld Nuclear Power Plant Simulation for Engineering Psychology Research and Process Control Applications

We demonstrate the development, rationale, and use of a gamified microworld nuclear power plant simulation for engineering psychology research and process control applications. The Rancor microworld was developed to address specific research needs in support of ongoing U.S. nuclear control room modernization efforts. The Rancor microworld serves as a platform for inexpensive cognitive psychology research that would otherwise not be as feasible in typical complex process control research settings. The gamified nuclear power plant simulator is simple enough that untrained, novice participants can quickly learn and control the system. The Rancor microworld is currently configured to support an investigation of attention and situation awareness in nuclear process control is discussed. The Rancor framework is flexible to support rapid modification for addressing research needs related to complex process control.

COSSplay: Validating a Computerized Operator Support System Using a Microworld Simulator

Our computerized operator support system microworld simulator with student operators approach is called COSSplay. COSSplay allows testing of specific interface elements such as alarm visualizations without the constraints of the surrounding nuclear control room elements typically associated with full-scope simulation studies. Approaches like COSSplay are ideal for first principles research in human factors and human-computer interaction. This paper highlights the uses of COSSplay as a complimentary approach to full-scope simulation studies for complex interface design.

A Peripherally-Located Virtual Instrument Landing Display Affords More Precise Control of Approach Path during Simulated Landings than Traditional Instrument Landing Displays

We compared the precision of simulated fixed-wing aircraft landing approaches with three different head-up display (HUD) formats: a) MIL-STD-1787B Cruise Mode, b) MIL-STD-1787B Instrument Landing System (ILS) Mode, and c) a virtual ILS HUD presented to the visual periphery. Non-pilot participants used simplified controls to guide a landing simulation under both day and night visual meteorological conditions. Experiment 1 confirmed that testing non-pilots with our experimental setting could induce the black-hole illusion, in which the approach is lower than appropriate at night. Experiment 2 compared landing performance aided by the three HUD formats under the same visual conditions. We found that both ILS displays improved approach path precision as compared to the MIL-STD Cruise Mode, and that the peripherally-located virtual ILS HUD reliably afforded the greatest precision. These results suggest that ILS approaches may be better supported by presenting a virtual ILS display to the visual periphery.