Warren F. Clement

Defining and Measuring Perceptual-Motor Workload in Manual Control Tasks

“Everyone knows” when he is subjected to a high mental workload or stress in a complex manual control task such as driving a car, steering a ship, or flying an airplane. Nevertheless, there is, as yet, no accepted definition of operator workload. This is mainly due to the incommensurate dimensions of various loading tasks and the lack of any comprehensive theory or validated models.

Development of a real-time simulation of a ship-correlated airwake model interfaced with a rotorcraft dynamic model

This paper describes a study outlining approaches for modeling mathematically in real-time simulation the kinematics of a ship and the dynamics of a rotorcraft interactmg aerodynamically within the ships awake on approach and landing aboard the moving ship. Specific recommendations are made to mod~fy an extant real-time simulation model of a rotorcrafl, including the interfacing of the ship-correlated airwake model with the blade element aerodynamic model of the rotor. A method for modeling the three-dimensional, spatially correlated airwake is also oresented.

Real-time piloted simulation of fully automatic guidance and control for rotorcraft nap-of-the-earth (NOE) flight following planned profiles

Developing a single-pilot all-weather NOE capability requires fully automatic NOE navigation and flight control. Innovative guidance and control concepts are being investigated to (1) organize the onboard computer-based storage and real-time updating of NOE terrain profiles and obstacles; (2) define a class of automatic anticipative pursuit guidance algorithms to follow the vertical, lateral, and longitudinal guidance commands; (3) automate a decision-making process for unexpected obstacle avoidance; and (4) provide several rapid response maneuvers. Acquired knowledge from the sensed environment is correlated with the recorded environment which is then used to determine an appropriate evasive maneuver if a nonconformity is observed. This research effort has been evaluated in both fixed-base and moving-base real-time piloted simulations thereby evaluating pilot acceptance of the automated concepts, supervisory override, manual operation, and reengagement of the automatic system.

AN ENGINEERING APPROACH TO AIRCRAFT SURVIVABILITY ENHANCEMENT ANALYSIS

In part because of its origins in the descriptive aspects of operations research, aircraft survivability analysis has, in the past, been more of an engineering art than a design discipline. Here we have adopted an engineering design definition of survivability and have formulated a mathematical optimization procedure for performing survivability analysis in such a way that the aircraft design process can be made to depend quantitatively on survivability criteria. The procedure first incorporates a sensitivity analysis of aircraft vulnerability based on a set of most likely engagements, so that the designer can identify components or subsystems with the greatest potential for survivability enhancement. Then we present a unified method for logically allocating the penalties invested in enhancing the survivability of several components or subsystems, subject to constraints on the overall “costs.” These constraints may include weight, lifetime fiscal cost, and measures of aircraft performance, for example. Th...