Brake Dynamometer Test Variability - Analysis of Root Causes Ford Motor Company

Format:

Conference/Event

Author/Creator:

Grochowicz, Grochowicz, author.

Contributor:

Abendroth, Harald

Agudelo, Carlos

Wollenweber, Karl-Heinz

Conference Name:

SAE 2010 Annual Brake Colloquium And Engineering Display (2010-10-10 : Phoenix, Arizona, United States)

Language:

English

Physical Description:

1 online resource

Place of Publication:

Warrendale, PA SAE International 2010

Summary:

Modern project management including brake testing includes theexchange of reliable results from different sources and differentlocations. The ISO TC22/SWG2-Brake Lining Committee established atask force led by Ford Motor Company to determine and analyze rootcauses for variability during dynamometer brake performancetesting. The overall goal was to provide guidelines on how toreduce variability and how to improve correlation betweendynamometer and vehicle test results. This collaborative accuracystudy used the ISO 26867 Friction behavior assessment forautomotive brake systems. Future efforts of the ISO task force willaddress NVH and vehicle-level tests.This paper corresponds to the first two phases of the projectregarding performance brake dynamometer testing and presentsresults, findings and conclusions regarding repeatability(within-lab) and reproducibility (between-labs) from differentlaboratories and different brake dynamometers. The new EKB 3008data exchange format was used by participating facilities to sharetest results using spreadsheet applications, help automate theevaluations, and simplify the different comparisons performed forthis project. This on one of the first practical applications forthe EKB 3008 format with several software platforms involved.In order to minimize variations caused by test parts, components(brake discs, brake pads, calipers and vehicle knuckles) werecarefully selected, prepared, and measured prior to testing.Special attention was given to: test procedure implementation,critical braking and testing conditions, dynamometer setup andcontrols, data collection, data processing and test evaluationroutines. Statistical analysis (Minitab® and ISO StatisticalMethods) were used to separate variability caused by test parts andcaused by the test setup. Based on the findings, the paper presentsguidelines for improving repeatability (within-lab) andreproducibility (between-labs) during regular testingactivities.Compared to vehicle testing, variability root-causeinvestigation using brake dynamometers is more efficient (lesssources of variation and less use of testing and engineeringresources) and under more controlled conditions. Findings from thisvariability study will support future improvement efforts forseveral laboratory and vehicle performance and NVH test procedureand techniques

Notes:

Vendor supplied data

Publisher Number:

2010-01-1697

Access Restriction:

Restricted for use by site license