Showing papers on "Vehicle dynamics published in 1968"

Vehicle dynamics in single vehicle accidents-validations and extensions of a computer simulation

Abstract: RESULTS OF THE SECOND YEAR OF A PROGRAM OF COMBINED THEORETICAL AND EXPERIMENTAL RESEARCH ARE SUMMARIZED THAT AIMED AT THE DEVELOPMENT OF ANALYTICAL MEANS OF STUDYING THE ENERGY CONVERSION CHARACTERISTICS OF ROADSIDE TERRAIN FEATURES AND OBSTACLES. THE REPORT OF THE RESEARCH CONSTITUTES ONE PART OF A BUREAU OF PUBLIC ROADS PROGRAM AIMED AT REDUCING THE INCIDENTS OF INJURY-PRODUCING ACCIDENTS THAT OCCUR IN COLLISIONS BETWEEN SINGLE VEHICLES AND FIXED OBJECTS ON OR NEAR THE ROADWAY. A COMPUTER SIMULATION OF THE DYNAMICS OF SINGLE VEHICLE ACCIDENTS IS VALIDATED BY MEANS OF COMPARISON OF THE MODEL PREDICTIONS OF VEHICLE RESPONSES WITH MEASURED RESULTS FROM A SERIES OF FULL-SCALE EXPERIMENTS. EXCELLENT CORRELATION IS ACHIEVED FOR A VARIETY OF VIOLENT MANEUVERS, MOST OF WHICH INCLUDE SIMULTANEOUS RIDE AND CORNERING RESPONSES. THE TEST PROCEDURES AND INSTRUMENTATION OF THE FULL-SCALE EXPERIMENTS ARE DESCRIBED IN DETAIL. PROPERTIES AND DIMENSIONS OF THE TEST VEHICLE, AS MEASURED BY THE FORD MOTOR COMPANY UNDER A SUBCONTRACT, AND TIRE PROPERTIES, AS MEASURED AND MADE AVAILABLE BY THE GENERAL MOTORS ENGINEERING STAFF, ARE SUMMARIZED. AN AUXILLIARY COMPUTER-GRAPHICS PROGRAM THAT PRODUCES PERSPECTIVE DISPLAYS OF THE SIMULATED VEHICLE AND TERRAIN FEATURES, OR OBSTACLES, IS BRIEFLY DESCIRBED AND SAMPLE DISPLAYS ARE PRESENTED. THE RESULTS OF FEASIBILITY STUDIES OF CLOSED-LOOP CONTROL OF THE SIMULATED VEHICLE, EXTENSION OF THE GENERALITY OF SPRUNG MASS IMPACT CAPABILITIES, AND APPLICATION OF THE SIMULATION TO THE TASK OF ACCIDENT RECONSTRUCTION ARE DISCUSSED. A SPECIALIZED VERSION OF THE VEHICLE SIMULATION THAT IS BEING DEVELOPED FOR USE IN STUDIES OF THE DETAILED DYNAMICS OF BRAKING IS DESCRIBED. SINCE REFINEMENTS AND MINOR CORRECTIONS HAVE BEEN INCORPORATED IN THE COMPUTER SIMULATION DURING THE COURSE OF THE VALIDATION STUDY, THE PRESENT REPORT INCLUDES UPDATED VERSIONS OF THE MATHEMATICAL MODEL DESCRIPTION AND OF THE EQUATIONS AND LOGIC THAT APPEARED IN AN EARLIER REPORT. /BPR/

Vehicle dynamics in single-vehicle accidents. validation and extensions of a computer simulation. interim technical report

Abstract: A COMPUTER SIMULATION OF THE DYNAMICS OF SINGLE VEHICLE ACCIDENTS, THAT WAS DEVELOPED WITHIN A PREVIOUSLY REPORTED PHASE OF THIS RESEARCH PROGRAM (CAL REPORT NO. VJ-2251-V-1, JULY, 1967) IS VALIDATED BY MEANS OF COMPARISON OF ITS PREDICTIONS OF VEHICLE RESPONSES WITH MEASURED RESULTS FROM A SERIES OF FULL-SCALE EXPERIMENTS. EXCELLENT CORRELATION IS ACHIEVED FOR A VARIETY OF VIOLENT MANEUVERS, MOST OF WHICH INCLUDE SIMULTANEOUS RIDE AND CORNERING RESPONSES. THE TEST PROCEDURES AND INSTRUMENTATION OF THE FULL-SCALE EXPERIMENTS ARE DESCRIBED IN DETAIL. PROPERTIES AND DIMENSIONS OF THE TEST VEHICLE, AS MEASURED BY THE FORD MOTOR COMPANY UNDER A SUBCONTRACT, AND TIRE PROPERTIES, AS MEASURED AND MADE AVAILABLE BY THE GENERAL MOTORS ENGINEERING STAFF, ARE SUMMARIZED. AN AUXILIARY COMPUTER-GRAPHICS PROGRAM THAT PRODUCES PERSPECTIVE DISPLAYS OF THE SIMULATED VEHICLE AND TERRAIN FEATURES, OR OBSTACLES, IS BRIEFLY DESCRIBED, AND SAMPLE DISPLAYS ARE PRESENTED. THE RESULTS OF FEASIBILITY STUDIES OF CLOSED-LOOP CONTROL OF THE SIMULATED VEHICLE EXTENSION OF THE GENERALITY OF SPRUNG MASS IMPACT CAPABILITIES, AND APPLICATION OF THE SIMULATION TO THE TASK OF ACCIDENT RECONSTRUCTION ARE DISCUSSED. A SPECIALIZED VERSION OF THE VEHICLE SIMULATION, THAT IS BEING DEVELOPED FOR USE IN STUDIES OF THE DETAILED DYNAMICS OF BRAKING IS DESCRIBED. SINCE REFINEMENTS AND MINOR CORRECTIONS HAVE BEEN INCORPORATED IN THE COMPUTER SIMULATION DURING THE COURSE OF THE VALIDATION STUDY, THE PRESENT REPORT INCLUDES UPDATED VERSIONS OF THE MATHEMATICAL MODEL DESCRIPTION AND OF THE EQUATIONS AND LOGIC THAT APPEARED IN THE EARLIER REPORT.

Tracked air-cushion vehicles for ground transportation system

Abstract: A general analysis of the forces and power requirements for transportation in a natural atmosphere is presented in the first part. A good picture of this problem can be achieved by drawing plots of stresses against speed. The second part surveys the major characteristics of a transportation service and their relation with the most important technical data concerning vehicle and track. The third part is concerned with the representation of the dynamic response of a tracked air-cushion vehicle (TACV) to excitation from track form's tolerances when the speed is varying. Some experimental results are shown.

On the lateral stability of articulated highway vehicles

Abstract: A THEORETICAL ANALYSIS IS BEING MADE OF THE LATERAL STABILITY CHARACTERISTICS OF CONVENTIONAL TRACTOR-TRAILER TRUCK COMBINATIONS. EQUATIONS OF MOTION ARE SOLVED BY USE OF A HIGH SPEED DIGITAL COMPUTER. PARTICULAR ATTENTION IS PAID TO THE INFLUENCE OF AERODYNAMIC FORCES WHICH ARE BEING STUDIED EXPERIMENTALLY USING SCALE MODELS TESTED IN A ROTATING ARM, WATER BASIN FACILITY. /SRIS/

Paper 2: Driver Behaviour in Controlling a Driving Simulator with Varying Stability

Abstract: The main content of the paper is concerned with the way people compensate their driving behaviour for degraded vehicle stability. It also outlines briefly the background of man–machine simulation and the use of driving simulators in the U.S.A. The problem was investigated by means of a fixed base driving simulator at the Davidson Laboratory as part of a larger programme concerned with driver behaviour.The simulator has a two-degree-of-freedom analogue simulation of the vehicle dynamics. The display system is photographic using a real road film, and the vehicle is subjected to random appearing disturbances of the wind gust type. The disturbance, vehicle, and driver behaviour are recorded both as analogue and digital signals for experimental control and later data analysis.The paper describes and gives the derived results from an experiment with nine subjects, driving two vehicles, one understeer and one oversteer, simulated to be travelling at 60 mile/h. While driving, the vehicles were subjected to a rand...

A study of automatic car following

Abstract: Virtually all proposed vehicle control systems for highway automation must include a steady-state car-following mode. This mode was intensively investigated for various situations where headway and relative velocity inputs were used. In addition, a fundamental relationship between the flow capacity of an automated highway and the small-signal longitudinal response of a vehicle was investigated. The predictions obtained from mathematical models of various car-following modes were compared to those from full-scale tests. It was concluded that a linear mathematical representation of the longitudinal dynamics was valid, and thus it could be used for predictive purposes. Furthermore, it was verified that flow capacity on an automated highway is sharply limited by certain vehicle characteristics if headway feedback is used for vehicle control.