 | Contract Research for the US Government |
Since our founding in 1957, contract research for the US Government has been a core element of STI's business. This work has been of great value to STI in developing new technologies, new products and new technical skills over the last half-century. The new technology and knowledge gained is then applied in our commercial consulting work. All of STI's products have benefited from our Government research. Most of this work has been for NASA, the Department of Defense (DOD), the Department of Transportation (DOT) and more recently the National Institutes of Health (NIH) and the Center for Disease Control (CDC). STI generally serves as a prime contractor, but often also serves as a subcontractor to other aerospace and defense firms, in these projects. In general this research has been focused on vehicle dynamics and automatic and manual control of vehicles, human factors and transportation safety. STI research projects for NASA have ranged from airships to hypersonic aerospace craft including a variety of studies on Space Shuttle flight control and current research on alleviation of loss of control in aircraft. STI has often supported the Air Force in design and problem solving of new aircraft as well as in research on human pilot behavior and flying qualities including current research on wavelet methods in system identification. STI has supported Naval aviation in the difficult problems of carrier landing and shipboard operation of helicopters. STI has also addressed problems of ship motion prediction and Navy crane ship dynamics. STI has done research relevant to the design of Army ground and air vehicles. Recent work has focused on improved simulation methods in ground vehicle dynamics, biodynamic modeling and characterization of terrain. Work for the DOT has included studies of fly-by-wire flight control issues for the FAA, many studies of automotive "active safety" for the National Highway Traffic Safety Administration (NHTSA) and studies of highway safety issues and "automated highways" for the Federal Highway Administration (FHWA). Work for the NIH/CDC has often involved research on innovative use of low cost driving simulators developed by STI for clinical assessment of specific diseases and injuries, driver training and rehabilitation. STI's research and development interests can be categorized in five areas Vehicle and Subsystem Dynamics and Control Almost all of STI's research involves a fundamental understanding of some dynamic system, generally a vehicle. These include aerospace, ground and marine vehicles and other mechanisms involving motion control (e.g. cranes, oil well drilling equipment, and telescopes). STI began with a focus on research and development in aircraft dynamics and flight control. Over the years, this is expanded to encompass most aerospace craft as well as ground and marine vehicles and their control systems. Research generally involves formulating vehicle equations of motion, analysis of dynamics, synthesis and analysis of control systems, simulation and flight or field testing. STI work for NASA on the Space Shuttle flight control system addressed significant new issues introduced by the pioneering digital fly-by-wire flight control system. Transport delays and the pitch rate command/attitude hold flight control system ushered in a new set of flight control and flying qualities problems. However, the understanding and solution of these problems have supported the spread of digital fly-by-wire systems to many new military and commercial aircraft. STI's experience with the Shuttle flight control system allowed STI to do further work in digital flight control for the FAA and in commercial consulting. Similarly, STI research on ground vehicle rollover for NHTSA has provided STI a knowledge base, which continues to expand in a distinctly different way in forensic engineering applications. Recent and Current ResearchVariable Speed Aerial Refueling Drogue (Air Force) Aeroservelastic Predictive Analysis Capability (Air Force AFFTC) Vehicle Performance on Upgrades and Downgrades (DOT/ FHWA) Ground Vehicle Dynamic Subsystem Modeling/Multibody Simulation (US Army TACOM) Road & Terrain Characterization for Vehicle Dynamics & Mobility Analysis (Army TACOM Advanced Propulsion Systems Design Tool (US Army TACOM) Aircraft Ground Loads Predictive Analysis (Air Force, sub to CMSoft Inc.)
Human-Machine Systems From its inception STI has maintained interest in manual control theory and understanding of the human operator. This arose from a need to understand flying qualities of aircraft and later the handling qualities of automobiles and other vehicles. This has led to a long history of STI research in this fascinating intersection of engineering and behavioral science and a staff that includes behavioral scientists as well as engineers. STI was a pioneer in the practical application of control theory to mathematical modeling of human operators. Throughout its history STI has coupled of mathematical models of vehicles with mathematical models of human pilots and other operators to provide a theoretical basis for understanding the dynamics and behavior of the overall closed loop system. This capability has provided an essential theoretical framework for the generally empirical handling qualities research carried out in simulators and flight and field test. One of STI's core ideas in this field is the "Crossover model". This elegantly simple concept has repeatedly provided insights into how humans control vehicles. The crossover model arose when classical control theory was applied to aircraft control and servo systems. These systems were intended to improve aircraft flying qualities, but the underlying control theory led to the crossover model and a deeper understanding of manual control. This research, initiated for aircraft, has been extended to understanding how humans control automobiles and many other manually control vehicles. Manual control theory has been extended to include neuromuscular dynamics and other biodynamic effects such as the influence of vibration. STI research in human-machine has also led to development of specialized devices for assessing fitness for duty, such as the STI Critical Task Tester (CTT). Other lines of research address the dynamics of flight directors and other display concepts to enhance manual control. Recent and Current ResearchT45 Ground Handling Characteristics Study (Boeing St. Louis for Navy ) Intelligent Displays for Time-Critical Maneuvering of Multi-Axis Vehicles (NASA Ames Research Center) Use of Dynamic Distortion to Predict and Alleviate Loss of Control (NASA Dryden) An Integrated Anthropometrics, Vehicle & Biodynamics Software Tool (US Army ARL) Algorithmic Cognitive Aid for Tracking and Predictive Targeting (US Army)
Simulation and Information Display for Training, Mission Rehearsal and Operations “Human-in-the-loop simulators” have been an essential tool in STI's research handling qualities, human operator modeling, manual control theory, and human behavior. STI's research in aircraft flying qualities has given us the opportunity to work with many of the most sophisticated aircraft research and development simulators operated by the US government and major aerospace firms. STI research involving simulators as provided considerable experience in formulating vehicle models for these simulators, designing simulator experiments, managing experiments and analyzing and interpreting the results. Over the years STI has developed its own simulator facilities including pioneering developments in automobile simulators. Experience gained from these Government research programs has allowed STI to develop low-cost simulators by exploiting personal computer and computer game technology. STI's low-cost driving simulator product, STISIM Drive, evolved from knowledge and technology gained largely in Government research. But by significantly reducing the cost of driving simulators STI has been able to create a new tool for clinical research. Coming full circle, STI, teamed with several university medical schools, is now using STISIM in innovative NIH/CDC studies of methods for assessment of cognitive degradation due to HIV/AIDS, brain injury and other problems. Over twenty years ago, STI began the development of a Parachute training simulator for the US Forest Service. This has evolved into PARASIM, a parachute training simulator now sold to the US and foreign military organizations. This in turn led to a research and development contract with the US Special Operations Command (SOCOM) to develop an advanced networked version of PARASIM that would allow Special Forces units to plan and rehearse missions where they jump as a team. This research also included developments to make the generation of the computer-generated visual scenes easier for end users to create. Such government-funded research and development in the area of sophisticated low cost, computer graphics have let new applications of this technology. This includes work in a current Air Force study to develop interactive 3-D maps for use by pilots in planning and rehearsing missions (CAVAPS). Ongoing STI research for the U.S. Navy has led to the development of an exciting new visual display technology called Fused Reality. Fused Reality allows trainees in simulators to see objects in the near field (e.g., their hands, vehicle controls), while revealing and interacting with a computer-generated virtual world in the far field. Recent and Current Research Tactical Insertion Mission Planning and Rehearsal Simulator (TIMPARS) (USSOCOM) Next Generation Visualization Tools for Mission Planning, Briefing and After Review (Air Force Helicopter Operations Aircrew/Crew Chief Trainer, (Navy) A PC Based Low Cost Simulator for Driver's Education (NIH/CDC - National Center for Injury Prevention and Control)
System Identification and Health Monitoring STI research routinely involves mathematical modeling of dynamic systems and human operators. The parameters in these models can be estimated by various means, but it is always of interest to refine and verify these estimates from measurements of system response in laboratory, flight or field tests. Thus STI has had a long interest in the development and application of parametric system identification methods. Applications to human operator models in closed loop control have been particularly challenging, but STI has been supported in this work by NASA and other agencies over the years. STI has long used frequency domain methods in these applications and recent STI research for NASA and the Air Force have extended this approach through new wavelet-based methods that make identification possible in transient events that cannot be addressed with traditional Fourier transform methods. System identification has long been a research and testing tool, but STI is increasingly taking this methodology in two real-world operational applications, which exploit the increased use of digital systems, networks and sophisticated sensors in vehicles. In a recent NASA study, STI has developed a concept for near real time detection of aircraft icing with an operational application of parametric system identification. In a current Navy study, STI is applying a wavelet-based system identification concept for health monitoring of aircraft servoactuators. In other research STI has applied wavelet-based methods to identify human pilot characteristics in simulator studies. STI is also develop completely different approaches to determining human operator characteristics, particularly as degraded by fatigue, alcohol and drugs. These include the Critical Task Tester which was originally developed under NASA funding for manned space applications of which has been applied by STI in a variety of applications for fitness for duty testing and fatigue research. A notable trend of this area of STI research is to take laboratory research methods and tools out of the laboratory and into near real time, automated operational applications such as improving transportation safety. Recent and Current Research Development of the Dynamic Icing Detection System (DIDS) (NASA Glenn) Flutter Suppression System Test Techniques (AFFTC/PKAE) On-Line Prediction of Lost of Control Using Wavelets (NASA DFRC) Dynamic Identification of Actuator Frequency Response Using Wavelets (Navy) Optimization of Parameter Identification for Flutter and Flying Qualities (Air Force AFFTC) Development of Simulations to Detect Impaired Drivers (NIH- NI Mental Health) Driving Simulator for Persons with Impaired Cognition (NIH NI of Child Health & Human Development) Procedures for Testing Older Driving Capabilities (NIH NI of Aging) Real-Time Detector of Human Fatigue (Air Force) Fatigue and Performance Modeling of Sleep-Deprived Soldiers (US army) Fast, Efficient, and Objective Detection of Sleepiness (NIH National Center for Injury Prevention and Control)
Intelligent and Autonomous Vehicles A major area of research interest for the US Government, particularly the DOD and NASA, is the development of autonomous "intelligent" vehicles. These include aerial, ground and marine applications. In a sense, this is simply a continuing evolution of the automation of vehicles, which began with the first aircraft flight control and autopilot systems. In a sense, this research and development thrust seeks to capture more of the human's higher-level supervision and decision-making capability in the vehicle control system. Thus work in this area connects to STI's long experience in the modeling of human operators, as well as the design conventional vehicle control systems. STI is currently studying the problem of autonomous control of High Altitude Airships for the Missile Defense Agency. This problem is complicated by the unconventional (compared to heavier-than-air aircraft) dynamics of airships, and the fact that conventional airship controls have been generally quite simple flight control systems. In work for the Navy, STI working with MIT has developed autonomous guidance concepts based on Focused Dynamic Programming for increasing the intelligence of cruise missiles. Recent and Current Research Long-Endurance, Autonomous Vehicle Control for High-Altitude Airships (DOD Missile Defense Agency (MDA)) Automated Path and Mission Planning for Aerial Platforms under Dynamic Conditions and Constraints (Navy)
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