5.0 The Topsy Story

Topsy is a modular system designed for measurement of all composite inertial, kinematic, and compliance parameters which appear in today's sophisticated mathematical simulation models. The emphasis in its design is not "production-line" testing, but research: the operator can observe the vehicle's reaction to developing forces; and as insights develop he can modify the test program as he goes along. Test errors are minimized by running all tests under servo control with continuous display of all data and recording of all known error sources, while the operators closely monitor the test and the developing data.

The test facility is organized around an "infrastructure" consisting of baseplates, vehicle locating fixtures, scales, hydraulic and pneumatic power sources, interchangeable valve assemblies and actuators, and transducers. These are organized along with specialized devices into the several forms required for the different tests.

When not in use, Topsy can be disassembled and stored on shelves and in cabinets.

The report "Topsy - A Modular Chassis Parameter Measurement System", available here in Adobe Acrobat PDF format, describes the overall system and the methodology, components, and instrumentation used in the various measurements.

The report is based on SAE Paper 971056, “Topsy - A Modular Chassis Parameter Measurement System”, which was also selected for inclusion in the SAE Transactions for 1997.

This page last modified 10/23/00