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The analysis and design of a computer-controlled system to coordinate the steering of the four wheels of an advanced vehicle system is presented. The application of modern control and estimation theory produces a Linear Quadratic Gaussian control design incorporating a directional dynamics model of the vehicle and models of the front and rear steering dynamics. Minimization of a performance based cost functional reduces sideslip angle variations, lateral acceleration and yaw velocity response times, yaw velocity and roll angle oscillations, and the use of dynamic steering control. The measurement system estimates the states for full-state-feedback from a set of practicable and realizable measurements, enables the development of the vehicle implementation and the eventual reduction of sensors needed, and adapts to changes in vehicle trim elevation and loading condition.

A computer-aided design method has been developed to predict, from limited information or estimates about system components, the performance of an electrohydraulic system under “feedback” control. The interactive computer program produces graphical solutions to step, ramp, and sine wave commands which allow the experimenter, designer, or engineer to optimize a particular experimental or prototype system for “best” performance in following the specified command. The simulated control system structure or an equivalent controller can then be implemented in hardware with an understanding of the realizable performance of the system before the components are purchased, fabricated, and assembled into the actual system.

The effects of physical motion and vehicle responsiveness on driver performance were investigated with a moving-base driving simulator. Twenty-four subjects were divided into four motion conditions ranging from no motion to roll plus yaw plus attenuated lateral translation. Each motion group drove the simulated vehicle with three levels of tire cornering stiffness. The presence of motion reduced driver control activity and path keeping deviations, but the effects of changing vehicle responsiveness were not disguised by reducing the number of motion cues. The results suggest, however, that motion cues become more important as driving maneuvers become more extreme.

The GMR Driving Simulator was used to study the performance of four teen-aged, novice drivers, two of whom had cerebral palsy. The purpose of this pilot study was to determine the potential of the simulator to discriminate between the driving abilities of medically handicapped and non-handicapped individuals. The study concentrated on the psychomotor aspects of lane-keeping performance in the presence of road curvature and environmental disturbances. The study indicates that a dynamically realistic driving simulator could be a valuable screening device for identifying potential performance difficulties in handicapped individuals prior to behind-the-wheel instruction.

This paper describes several applications of telemetry in making experimental measurements inside the rotary combustion engine. Short-range radio telemetry was used as the wireless data link from transducers on the moving rotor to the stationary housing of a firing engine. The procedures used to measure motion, temperature, and pressure in this difficult and hostile environment are described in detail. The problems encountered and the limitations of the measurement system are discussed in order to illustrate the application of this experimental method.

This paper describes an analytical study of a commercial tractor-semitrailer vehicle which is subjected to various brake applications in a turn. A hybrid computer simulation of the vehicle is used to investigate the effect of loading condition, brake-torque distribution, brake application times, and load-sensitive brake-torque control on the directional response of the vehicle during braking.