Inductive position sensor with vernier and coupling scale

Abstract

The inductive position sensor comprises a scale (10) having a series of conductive loops spaced apart at a pitch T, and a vernier (20) having conductors forming a series of interleaved hairpin loops spaced at a pitch T, so The inducing vernier conductors (21 to 23; 42, 44) and the inducing vernier conductors (31 to 33; 41, 43) are arranged in two separate sets of interleaved conductors, between the inducing conductors and the inducing conductors of the second set The coupling occurs only via the scale loop. The sensor is simple, durable, accurate, insensitive to external electromagnetic fields, and tolerates misalignment between the vernier and scale.

Description

technical field [0001] The invention is an inductive position sensor comprising a scale and a vernier movable relative to each other along a measuring path, said scale comprising one or several conductors forming a series of conductors spaced at a pitch T along said measuring path A conductive loop, the wiper comprising an inducing conductor and a sensing conductor connected to an electronic measurement circuit, each conductor forming a series of interleaved hairpin turns spaced at a pitch T along the measurement path. Background technique [0002] US Patent No. 5,804,963 discloses an inductive position sensor with the above features. The position of the wiper relative to the scale along the path is derived from coupling measurements between the inducing and sensing wiper conductors via the scale conductor. The magnetic fields generated and picked up by the vernier and scale conductors of such a sensor have opposite polarities every pitch T along the measurement path. Such...

AI Technical Summary

Problems solved by technology

But the direct coupling between the vernier conductors is very important, and when the coupling via said scale is reduced, i.e. the scale-to-vernier gap increases, the measurement error becomes larger

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