770511 ANew Test Control and Data Acquisition System for Experimental Testing of Automatic Transmissions M.D.Smith and B.R.Trewartha Detroit Diesel Allison Division ofGeneral Motors Corporation THE ENGINEERING TEST FACILITY for transmission products atDetroit Diesel Allison currently encompasses 65,000 sq.ft.offloor space. SeeFig. 1.This facility isused toconduct fourma jortypes ofexperimental testing ofthe DDA transmission product line. These are: engine powered testing, Fig. 2,where gasoline, diesel, or gasturbine engines ranging from 100hpto1500hp provide thepower input tothetransmission; DC dynamometer-powered testing, Fig. 3,where DC dynamometers ranging from 160hpto1440 hp provide thepower input tothetransmissions; vehicle testing, wherein thetransmission isroad tested in anactual vehicle test-bed environment; andcom ponent testing, wherein theindividual transmission parts and subassemblies aretested forfunction, performance, anddurability. Thepresent testfa cility also provides thenormal testsupport func tions.TEST FACILITY MODERNIZATION InJuly 1974 approval wasgiven toexpand andmodernize theengine- anddynamometer-powered transmis siontestfacilities. Fig.4shows anareaadjacent to thepresent testfacility thatwasannexed toprovide tennew engine-powered teststands and sixnew DC-dynamometer-powered teststands. Moderniza tion ofthisarea, which comprises 30,000 sq.ft.,in cluded thefollowing major items: Building modifications (walls, floors, doors, windows, etc.) New utility services (oil,water, fuel, air,elec tric and heating, ventilation, and aircon ditioning) DCmotoring dynamometer systems (160 hpto1440 hp) Twenty-one new eddy current absorption dy namometer systems (800 hpto1600 hp) ABSTRACT Anew computerized test control anddataac quisition system forexperimental testing of transmissions hasbeen developed. Thepurpose of thetestsystem istoprovide abetter transmission product byfacilitating testactivities, which include performance, development, anddurability testing. The test system iscapable ofhandling many different models ofautomatic and powershift transmissions, varying insize, horsepower, andcom plexity.Thesystem isdedicated totestcelloperation and isnotused fornon-test-related functions. Itisa mini-computer-distributed system commonly referred toasahierarchical system. The system consists ofsatellite, intermediate, andhost com puter levels. Itisused inconjunction with ten engine-powered test stands and sixDC-dyna mometer-powered teststands. This paper covers operating andsystem features oftheoverall test svstem. 2046 0096-736X/78/8603-2046$02.50 Copyright ©1978 Society ofAutomotive Engineers, Inc. New TextDownloaded from SAE International by University of New South Wales, Monday, September 17, 2018 Anew environmental test room (-85°F to +200°F) Anew computerized testcontrol anddataac quisition system Thelastitem isthesubject ofthispaper. Transmission Testing, asdiscussed inthispaper, isrelated toexperimental performance, develop ment anddurability rather than production testing. Unlike production testing where aninitial installa-tion may gounchanged forlongperiods oftime, the testing inthisenvironment covers many different transmission models andconfigurations. Detroit Diesel Allison builds many models of automatic andpowershift transmissions generally classified inoneofthefollowing categories deter mined bythemarket segments inwhich they are used. SeeFig. 5. Hauling (AT, MT, HT, CLT, DP, &V) 2047 Downloaded from SAE International by University of New South Wales, Monday, September 17, 20182048 M.D.SMITH AND B.R.TREWARTHA Cycling (TT &CRT) Military (X,XTG &CD) These transmissions range insize, horsepower, complexity, andconfiguration from thesmallest on highway product, theAT540, which at100-200 hp hasfourforward ranges andonereverse range, inan inline configuration, totheMain Battle Tank Power Train, theX1100, at1500 hp,which hasa transmission capable offour forward and two reverse speeds plus infinitely var