Non-contacting Transmission Range Selector Sensor Package Optimization for Improved Reliability in Automatic Transmissions Delphi Powertrain Systems

Format:

Conference/Event

Author/Creator:

Thomson, Thomson, author.

Contributor:

Collins, Duane

Martínez, Daniel

Conference Name:

SAE 2010 World Congress & Exhibition (2010-04-13 : Detroit, Michigan, United States)

Language:

English

Physical Description:

1 online resource

Place of Publication:

Warrendale, PA SAE International 2010

Summary:

Ever since the implementation of diagnostics and electroniccontrol systems on automatic transmissions, various forms oftransmission gear selection feedback has been used. The traditionalmechanization uses a feedback switch with mechanical contacts thatindicate the selected gear discretely or through a grey codeoutput.Switch reliability above the industry standard was made possiblethrough the use of non-contact technology. Multi-Hallmechanizations have been used by others in recent years howeverthis type of product has been simplified by using a single linearHall device; reducing component count and the number of connectorinterfaces. Furthermore, a reduction in the number of electricalconnections led to improved system reliability and cost.Optimization of this package was made possible through the useof a multi-tool, multi-objective, single field focus using advanceddesign optimization software, robust engineering techniques andShainin® tools.In this optimized design a unique system of magnets andshaped-flux concentrators surround a linear-Hall device to providea sensor package which is robust to stray external ferromagneticfields. Flux strength is measured by the linear-Hall element heldwithin a constant air-gap. Shaped flux concentrators then minimizethe fringe effects that are common to magnetic fields which occureven when ferromagnetic concentrators are used. More importantlyconcentrator shapes linearize the flux output and eliminate theneed for external compensation tables.For added diagnostic capability it will be shown that themagnetic package accepts single or multiple linear-Hall devices inorder to provide redundant outputs. With this design'sflexibility single or multiple linear output signals can beprovided over a range of up to 80 degrees of rotation or 50 mm oflinear travel.Re-shaping this magnetic package into a linear motion sensor wasmade possible by a robust optimization using an L18 array that wasthen completed using Ansoft's Maxwell 3D tools. Linearity wasfurther enhanced using a Heeds advanced optimization tool.Although beyond the scope of this paper, it can be mentionedthat the final mechanization is very robust against externalsources that typically cause electromagnetic interference. Theshaped concentrators, to be described, affectively buffer amagnetic field over a large area. Because the sensing device isencompassed within a strong magnetic field, this package has alsoproven itself robust against any ferromagnetic particle build-upwhich may occur over several lifetimes of durability tests

Notes:

Vendor supplied data

Publisher Number:

2010-01-0189

Access Restriction:

Restricted for use by site license