Sharp R.S.,University of Surrey |
Watanabe Y.,Mechanical Simulation Corporation
Vehicle System Dynamics | Year: 2013
Motorcycle racing teams occasionally experience speed-limiting vibrations of around 25 Hz frequency in mid-corner. The nature of the vibrations has not been closely defined yet and the mechanics are currently not properly understood. Conventional motorcycle-dynamics models are shown here to reveal the existence of a vibration mode that aligns with the experience being referred to, suggesting some explanations. Root loci for variations in speed or cornering vigour, demonstrating modal characteristics for small perturbations from trim states, are employed to indicate how the mode responds to changes in operation and design. Modal participation is examined for a lightly damped case. Influences on the natural frequency and damping of the mode are found and a way of stabilising the mode is suggested. © 2013 Taylor and Francis Group, LLC.
Sayers M.W.,Mechanical Simulation Corporation
SAE International Journal of Materials and Manufacturing | Year: 2011
The major actions that move a highway vehicle are the forces and moments generated between the tire and ground; hence, the validity of a simulated vehicle test depends on the quality of both the tire model and the characterization of the ground surface. Other actions come from aerodynamic forces and moments that are affected by the relation of the vehicle body to the ground surface. This paper describes how the ground can be characterized to cover features of interest for most vehicle simulation scenarios involving pavements or other rigid surfaces. The 3D surface is built from tabular data related to specified properties of a road surface such as horizontal geometry, design elevation changes related to curves and drainage (i.e., banking of turns, cross-slope, ditches, etc.), elevation changes due to hills and other major grades, and disturbances and unique features such as bumps and holes. Broadband random-type road roughness is also included. The road model is intended to work with data from many sources, including GPS measurements, design data, road roughness profile measurements, 3D laser-scanned terrain topology, and specific scenarios created by engineers. A road axis system is defined for describing vehicle motions relative to an inclined road surface for aerodynamics and applications where engineers are concerned with motions of the vehicle relative to the ground surface. The methods described in this paper are demonstrated using the commercial CarSim® vehicle dynamics simulation package. © 2011 SAE International.
Mechanical Simulation Corporation | Date: 2011-08-05
Computer software for simulating and analyzing the dynamic behavior of motor vehicles; Simulators for driving or control of vehicles; Software for processing images, graphics and text.
Mechanical Simulation Corporation and Knable & Associates Inc. | Date: 2007-07-24
DOWNLOADABLE COMPUTER SOFTWARE FOR USE IN KINETIC COMPLIANCE ANALYSIS OF VEHICLE SUSPENSION SYSTEMS.
Mechanical Simulation Corporation | Date: 2007-04-24
Computer Software for Computational Vehicle Dynamics.