US 4,537,075 AGranted

Position control

AssigneeBritish Aerospace Public Limited Company

InventorsGraham Jackson, Ryszard Surawy

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Abstract

In ultrasonic echo testing to detect flaws in manufactured articles, raw materials and such it is desirable to maintain a predetermined spacing and relative orientation of the ultrasonic transducer and the surface of the tested article. Thus, automatic scanning of the article by repetitively translating the transducer across its surface is difficult or impossible if the article surface is anything other than flat. Herein, a plurality of satellite transducers are mounted with and around a primary transducer on a motor-adjustable articulated transducer head in ultrasonic test equipment so as to receive part of the main beam echo and thereby produce respective distance signals, which signals are used by control apparatus to control the transducer head adjustment motor and thereby regulate the primary transducer position relative to the tested article.

Claims9

Dependent claims

Ultrasonic test equipment, comprising

a transducer head having primary transducer means, mounted on said transducer head, for emitting a pulsed beam of ultrasonic energy towards a workpiece to be tested and for receiving energy reflected back from said workpiece for subsequent formation of signals indicative of workpiece flaws;
drive pulse supply means, connected to said primary transducer means, for causing said primary transducer means to emit said beam;
and
motor drive support system means for relatively moving said workpiece and transducer head to scan said beam across said workpiece and, during such scanning, for automatically regulating the angle of incidence between said beam and a surface of said workpiece, said support system means including
at least two receive-only satellite transducers supported by said transducer head at respective sides of the axis of said beam so as to receive respective portions of said reflected energy of each pulse of said beam emitted by said primary transducer means at respective times dependent upon said angle of incidence,
an angle control motor and associated motor drive circuit means for relatively moving said transducer head and workpiece to vary said angle of incidence, and
time comparator means, connected between said satellite transducers and said motor drive circuit means for controlling said drive circuit means by comparing the timing of said respective reflected energy pulses received by said satellite transducers.

4 more elements

Ultrasonic test equipment, comprising

transducer head means for directing a pulsed beam of ultrasonic energy towards a workpiece and for receiving energy reflected back from said workpiece;
and
motor drive support system means for relatively moving said workpiece and said transducer head and, during such movement, for automatically controlling the relative position of said transducer head and workpiece so as to regulate the angle of incidence between said beam and a surface of said workpiece surface;
wherein said transducer head means comprises
a housing,
a primary transducer within said housing for producing pulses of ultrasonic energy and for receiving said reflected energy,
at least two receive-only satellite transducers mounted within said housing at respective sides of said primary transducer so as to receive respective portions of said reflected energy and output respective electrical signals indicative thereof, and
duct means extending between an aperture in a wall of said housing and a position adjacent said transducers, at which position the duct means defines a bell mouth opening towards said transducers, wherein said duct means directs energy produced by said primary transducer to form a directional energy beam emitted from said aperture and also directs said reflected energy back to said transducers, and wherein
said support system means includes means for deriving a signal for controlling the relative position of said transducer head and workpiece by comparing the timing of said respective electrical output signals produced by said satellite transducers.

6 more elements

Dependencies are inferred from the claim text.

Facts

Application: 06/616,780Filed 1 Jun 1984 · continuation
Priority: GB 812302425 Jul 1981
Granted: 27 Aug 1985
Term ends: Not estimatedThe source records don’t support an estimate.

Classification4 codes

G01N 29/30
Details , e.g. general constructional or apparatus details: arrangements for calibrating or comparing, e.g. with standard objects
G05D 3/12
Control of position or direction: using feedback
G01N
Investigating or analysing materials by determining their chemical or physical properties
G05D
Systems for controlling or regulating non-electric variables