A non-contact strain-gage torque sensor for automotive servo-driven steering systems
✍ Scribed by E. Zabler; A Dukart; F. Heintz; R. Krott
- Publisher
- Elsevier Science
- Year
- 1994
- Tongue
- English
- Weight
- 783 KB
- Volume
- 41
- Category
- Article
- ISSN
- 0924-4247
No coin nor oath required. For personal study only.
✦ Synopsis
Tappmg of one or more torques (ranges 10 N m and 60 N m) on the steering column of an automobile for the purpose of sexvo wntml must sat&y both high accuracy requirements and hlgb safety reqmrements A suggestlon for developing a low-cost solution to this problem IS described below Strmn gages optunally sabsfy both these reqmrements however, for cost reasons, these are not applied directly to the steering column but to a prefabncated flat steel rod that IS laser welded to the torque rod of the steenng column The measunng direction of the strain gages IS under 45" to the steermg-column axis The stram gages are either vacuum metalhzed onto the support rod as a thm film or lammated m a particularly low-cost way by means of a f&-type mtermedlate carrier The relatrvely low output signals of the measurmg reSIstor bridge are amphfied on site (on the steermg column) with an Integrated electromc evaluation cucmt and converted mto a frequency-analog, highly mterferenceproof slgnal Neither collector rings nor cables are needed to connect the signal output and power supply to the fixed parts of the body Both connectlons are made totally non-contact by means of a very sunple and lowcost rotary transformer, which surrounds the steenng column concentraxlly and has two separate wmdmg chambers In this case, It IS practically Impossible for air-gap fluctuations and smnlar mterferences to falsify the frequencyanalog measurmg slgnal 1.1ntrtKluct10n