FMVSSPart581

Purpose

Federal Motor Vehicle Safety Standards (FMVSS) Part 581 specifies requirements to minimize damage tothe front and rear ends of passenger cars in low-speed collisions. The equipment described will perform testsaccording to the FMVSS Part 581 specification, plus perform other Research and Developmental Testing.

Description

Two different test devices are required to perform Part 581 tests: A Pendulum Tester and a Barrier ImpactTester, described as follows.

PendulumThe pendulum tester consists of a large steel frame that supports a swinging mass via a parallelogram linkage.The mass frame supports contact planes and an impact ridge conforming to the Part 581 Bumper Standard.The height of the impact ridge is infinitely adjustable by motor-driven screw jacks, located at the corners ofthe support frame, in a range of from 15 to 21 inches. Mass plates can be added or removed to adjust thependulum mass from 1200 to 4500 pounds. Impact speeds of up to 10 mph (16 kph) can be obtained bydrawing the pendulum pull-back cable to a pendulum angle of up to 45° before releasing the quick-disconnectholding latch.

Instrumentation, consisting of 8 ea 2,000 lb load cells, 3 ea 25,000 lb load cells and 4 ea 10 g accelerometersto record the inertia-compensated contact forces of up to 20,000 on each contact plane and to 60,000 lb onthe impact ridge. Computer calculations include bumper contact force, pendulum and vehicle velocities,vehicle deflection, and energy transfer.

Computer, printer, and control electronics are housed in a vertical rack enclosure especially prepared forelectronic instrumentation

Low-Speed BarrierA 25 Hp programmable acceleration/velocity DC motor and winch cable system propels a test vehicle atspeeds up to 10 mph along a 23.5 m guide rail. The vehicle is then released and impacts the 30 ton capacityload barrier. A laser optical speed trap measures the impact velocity. Impact force, vehicle acceleration andbumper (vehicle) deformation are recorded by the computerized data acquisition system (DAS).

The 25 Hp programmable motor is speed controllable to within ±0.01% error. Normally the maximum testspeed is limited to 16 kph for all vehicle masses up to 3000 kg. Maximum system speed capabilities are

Vehicle Mass (kg)Max Speed (kph)

1000 32150030200026250023300021

The barrier is made of a steel frame imbedded in concrete and measures 1.5 m high x 1.5 m deep x 3 m wide.Optional Front-into-Angle-Barrier and Rear-into-Pole test fixtures are also available and are detailed in thefollowing Insurance Institute for Highway Safety Report, “Low-Speed Crash Test Protocol.”

Additionally, an optional test cart is available for mounting bumper systems for impact by either the Pendulum

TMSI Test Measurement Systems, Inc. • 150 Springside Drive • Suite A100 • Akron, Ohio 44333

Sales: (888) TMSI-USA • Tel: (330)668-2010 • Fax: (330) 668-2365

http://www.tmsi-usa.com

or Barrier Testers. Cart mass may be varied using mass plates and impact data are recorded by load cells andaccelerometers.

Control System

All electronic control and data acquisition systems provided by TMSI are integrated completely for controlby a single PC with Windows® 95/NT-based software for intuitive operation with minimal operator training.TMSI MicroTeStationTM housed in 20.5 W x 72 H x 24 D inch instrument rack enclosure. Includes:

#Intel 80686 Pentium® Based Microprocessor Industrial Computer#Standard Hard Disk Drive#Single 3.5 in. Floppy Disk Drive#A Removable Disk Drive for Data Archival and Storage#Random Access Memory#SVGA Color Monitor#Windows® 95/NT Operating System#32 Chnl A/D, DIO On-board data acquisition/reduction system#16 Chnl Anti Alias Filters#Telephone Modem#Color Printer

Data Acquisition/Control

Parallel CPU full-time data acquisition/control processing is accomplished by MicroStar Data Acquisition

Processors (DAP) which feature on-board CPU and memory as well as Analog to Digital and Digital toAnalog converters. Closed-loop digital PID control is achieved on-board the DAP unit for full softwaretunability of the DC motor drive in velocity and acceleration feedback control.

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MicroStar DAP 3000/16 Data Acquisition Processor to operate in parallel with the PentiumBased Microprocessor

ComputerBoards CIO/DIO 24 SSR, Solid State Relays for sensing and controlling digitalinputs and outputs

A single control console and computer operates both the Pendulum and Barrier Testers.

Software

ImpactTESTTM is TMSI's data acquisition/reduction program to operate the on-site MicroTeStation inWindows 95 presentation, control tests according to FMVSS Part 581; reduce and present tabular and graph-ical reports, and archive tests results to hard or floppy disk.

TMSI Test Measurement Systems, Inc. • 150 Springside Drive • Suite A100 • Akron, Ohio 44333

Sales: (888) TMSI-USA • Tel: (330)668-2010 • Fax: (330) 668-2365

http://www.tmsi-usa.com