TERMIUM Plus^®

Fiche 1,  Justifications,  Anglais

Record number: 1, Textual support number: 1 DEF

The phenomenon exhibited by laser gyros that is characterized by frequency locking of the clockwise and counterclockwise beams at low input rates.  3, fiche 1, Anglais, - lock%2Din

Record number: 1, Textual support number: 1 CONT

Lock-in is a fundamental physical phenomenon associated with all oscillating devices. Laser gyros exhibit the same phenomenon, in that the coupling mechanism is the reflection of light from one laser beam back along the path where it interacts with the oppositely traveling beam. This is called backscatter and is caused primarily by imperfect mirrors.  4, fiche 1, Anglais, - lock%2Din

Record number: 1, Textual support number: 1 OBS

[Lock-in] is caused by the coupling of energy between the laser beams and results in a threshold error near zero input angular rate unless a corrective means, such as biasing, is used.  3, fiche 1, Anglais, - lock%2Din

Fiche 1,  Justifications,  Français

Record number: 1, Textual support number: 1 CONT

L'origine physique [du] blocage des oscillations [gyromètre laser] tient à ce qu'une partie de chacun des rayonnements se déplaçant dans un sens donné est renvoyée dans l'autre sens; ce renvoi est notamment dû aux irrégularités de surface des miroirs et aux variations d'indice de ces miroirs.  3, fiche 1, Français, - blocage

Record number: 1, Textual support number: 2 CONT

La structure simple du gyrolaser lui confère une excellente fiabilité et une bonne précision [...] Les défauts de surface des miroirs, même infimes, provoquent la rétrodiffusion d'une partie de chaque rayon qui se couple alors avec le rayon se propageant dans l'autre sens. Il se crée ainsi un couplage (lock-in) entre les faisceaux lasers et une zone aveugle pour les vitesses angulaires faibles.  2, fiche 1, Français, - blocage

Fiche 1,  Justifications,  Espagnol

Fiche 2,  Justifications,  Anglais

Record number: 2, Textual support number: 1 CONT

Each time its value crosses through zero velocity, a small lock-in error usually occurs.  2, fiche 2, Anglais, - zero%20velocity

Fiche 2,  Justifications,  Français

Record number: 2, Textual support number: 1 CONT

Ce tremblement étant sinusoïdal, il change de sens deux fois par cycle de sorte que chaque fois que le taux de rotation passe par la valeur zéro, la mesure est faussée de l'erreur d'accrochage.  2, fiche 2, Français, - valeur%20z%C3%A9ro

Fiche 2,  Justifications,  Espagnol

Fiche 3,  Justifications,  Anglais

Record number: 3, Textual support number: 1 CONT

... for a mechanically dithered RLG [ring laser gyro], non-linearities(sidebands) appear in the input-output scale factor curve for an input rotation rate which is a harmonic of the dither frequency... There are two disadvantages to dithering. One is that the rotation rate periodically passes through zero where lock-in occurs. This results in a "random walk" angular position error. The other is that the vibration of the gyro body may affect other components or the gyro may be affected by other vibration sources. The laser gyro need not be mechanically dithered. The same result may be achieved by optical devices.  1, fiche 3, Anglais, - mechanically%20dithered%20RLG

Record number: 3, Textual support number: 1 OBS

dither: To periodically tilt from side to side.  4, fiche 3, Anglais, - mechanically%20dithered%20RLG

Fiche 3,  Justifications,  Français

Fiche 3,  Justifications,  Espagnol

Fiche 4,  Justifications,  Anglais

Record number: 4, Textual support number: 1 CONT

... for a mechanically dithered RLG [ring laser gyro], non-linearities(sidebands) appear in the input-output scale factor curve for an input rotation rate which is a harmonic of the dither frequency... There are two disadvantages to dithering. One is that the rotation rate periodically passes through zero where lock-in occurs. This results in a "random walk" angular position error. The other is that the vibration of the gyro body may affect other components or the gyro may be affected by other vibration sources. The laser gyro need not be mechanically dithered. The same result may be achieved by optical devices.  1, fiche 4, Anglais, - mechanically%20dithered

Record number: 4, Textual support number: 1 OBS

dither: To periodically tilt from side to side.  2, fiche 4, Anglais, - mechanically%20dithered

Fiche 4,  Justifications,  Français

Fiche 4,  Justifications,  Espagnol

Fiche 5,  Justifications,  Anglais

Record number: 5, Textual support number: 1 CONT

Each time its value crosses through zero velocity, a small lock-in error usually occurs.  1, fiche 5, Anglais, - lock%2Din%20error

Fiche 5,  Justifications,  Français

Record number: 5, Textual support number: 1 CONT

Ce tremblement étant sinusoïdal, il change de sens deux fois par cycle de sorte que chaque fois que le taux de rotation passe par la valeur zéro, la mesure est cependant faussée de l'erreur d'accrochage.  1, fiche 5, Français, - erreur%20d%27accrochage

Fiche 5,  Justifications,  Espagnol