Vibratory gyroscope, vibrator used in this gyroscope, method for analyzing vibration of the vibrator, method for supporting the vibrator, and method for manufacturing the vibratory gyroscope

A vibrator comprising:

• a base part having an upper surface and a lower surface;
• a plurality of vibration pieces connected to said base part;
• a recess formed in said lower surface of said base part within a domain where a detecting vibration in said vibrator is smallest and in a vicinity of the center of gravity of said vibrator;
• and
• a supporting member for supporting said vibrator in the region of said recess.

A method for supporting a vibrator that includes a plurality of vibration pieces connected to a base part, comprising the steps of:

• applying a driving vibration to at least one of the vibration pieces to allow a detecting vibration to occur in the vibrator;
• computing amplitude ratios of the detecting vibration along each point of the vibrator to a maximum amplitude of the detecting vibration in the vibrator, by means of a natural mode analysis by a finite element method;
• using the computed ratios to detect a domain within the vibrator where the detecting vibration is smallest;
• and
• supporting the vibrator within the domain and in the vicinity of the center of gravity of the vibrator.

A method for supporting a vibrator that includes a plurality of vibration pieces connected to a base part, comprising the steps of:

• applying a driving vibration to at least one of the vibration pieces to allow a detecting vibration to occur in the vibrator;
• computing amplitude ratios of the detecting vibration along each point of the vibrator to a maximum amplitude of the detecting vibration in the vibrator, by means of a natural mode analysis by a finite element method;
• using the computed ratios to detect a domain within the vibrator where the detecting vibration is smallest;
• and
• positioning a supporting recess within the domain and in the vicinity of the center of gravity of the vibrator.

A method for manufacturing a vibratory gyroscope, comprising:

• providing a vibrator that includes a plurality of vibration pieces connected to a base part;
• applying a driving vibration to at least one of the vibration pieces to allow a detecting vibration to occur in the vibrator;
• computing amplitude ratios of the detecting vibration along each point of the vibrator to a maximum amplitude of the detecting vibration in the vibrator, by means of a natural mode analysis by a finite element method;
• using the computed ratios to detect a domain within the vibrator where the detecting vibration is smallest;
• and
• supporting the vibrator within the domain and in the vicinity of the center of gravity of the vibrator;
• wherein the gyroscope detects the turning angular rate based on a detecting vibration excited in the vibrator as a result of the turning angular rate when a driving vibration is applied to at least one of the vibration pieces.

A method for manufacturing a vibratory gyroscope, comprising:

• providing a vibrator that includes a plurality of vibration pieces connected to a base part;
• applying a driving vibration to at least one of the vibration pieces to allow a detecting vibration to occur in the vibrator;
• computing amplitude ratios of the detecting vibration along each point of the vibrator to a maximum amplitude of the detecting vibration in the vibrator, by means of a natural mode analysis by a finite element method;
• using the computed ratios to detect a domain within the vibrator where the detecting vibration is smallest;
• forming supporting recesses in said vibrator around the domain;
• and
• supporting the vibrator in the vicinities of at least two of the supporting recesses and in the vicinity of the center of gravity of the vibrator;
• wherein the gyroscope detects the turning angular rate based on a detecting vibration excited in the vibrator as a result of the turning angular rate when a driving vibration is applied to at least one of the vibration pieces.