Method of adjusting the zero-point of rate type sensor

• US 4,470,124 A
• Filed: 06/01/1982
• Issued: 09/04/1984
• Est. Priority Date: 06/01/1981
• Status: Expired due to Term

• Current Assignee: Honda Giken Kogyo Kabushiki Kaisha (Honda Motor Company)
• Original Assignee: Honda Giken Kogyo Kabushiki Kaisha (Honda Motor Company)
• Inventors: Ichikawa, Akira, Takahashi, Tsuneo, Tagami, Katsutoshi, Yasui, Shinichiro, Hidaka, Akira, Kitasei, Yasuzi
• Primary Examiner(s): Chin, Gary
• Application Number:
  US06/384,011
• Time in Patent Office: 826 Days
• Field of Search: 364/424, 364/571, 364/565, 364/575, 73/1 D, 73/1 E, 73/178 R, 73/488, 73/516 R, 73/516 LM, 73/517 R
• US Class Current: 702/87
• CPC Class Codes: B60G 17/01908 Acceleration or inclination sensors characterised by the use of gyroscopes B60G21/08
• CPC Class Codes: G01C 25/00 Manufacturing, calibrating, cleaning, or repairing instruments or devices referred to in the other groups of this subclass testing, calibrating or compensating compasses G01C17/38
• CPC Class Codes: G01D 3/06 with provision for operation by a null method
• CPC Class Codes: G07C 5/0825 using optical means

Abstract

A method of zero-level adjustment of a rate sensor wherein the zero-level adjustment in the detection of yawing rate is obtained by subtracting a quantity of drift of an output from the rate sensor during the period of time that the vehicle is stopped or standing still from a subsequent output therefrom in the normal travelling operation of the vehicle. The current state of the vehicle, i.e., whether it is travelling or standing still, is detected by a travel distance sensing device which generates electric pulse signals for a given unit distance travelled by the vehicle; and the sampled outputs from the rate sensor are averaged for the period from immediately after the detection of a standing still state of the vehicle to the moment just before a starting of travel thereof. The thus-obtained averaged value is determined as a current drifting value of the sensor and is subtracted from a current angle of deviation value obtained during normal travel of the vehicle. A substantial improvement in accuracy of zero-level adjustment is thereby attained.

Claims

1. A method of adjusting the zero-level of a rate sensor which comprises the steps of:

detecting a current state of an automotive vehicle, whether it is in a state of travel or standing still, in accordance with the output from travel distance sensing means which generates electric pulse signals for a given unit distance travelled by said vehicle;

averaging the sampled outputs from said rate sensor installed upon said vehicle, during the period from immediately after the detection of a standing still state thereof to the moment right before a starting of travel thereof;

determining the thus-obtained averaged value as a current drifting value of said sensor; and

subtracting the thus-determined drifting value from a current angle of deviation value as obtained in a turning motion during the normal travelling operation of said vehicle;

whereby a proper detection of a current drift value of said rate sensor is ensured, free from any disturbances, and high accuracy in the zero-level adjustment of said rate sensor is ensured in accordance with the thus-obtained proper value of drifting.

2. A method of adjusting the zero-level of a rate sensor in accordance with claim 1, which further comprises the step of:

nullifying a sampling value having a level exceeding a predetermined value as obtained during said averaging step.