Vehicle velocity detecting device

• US 6,163,742 A
• Filed: 07/02/1999
• Issued: 12/19/2000
• Est. Priority Date: 07/02/1998
• Status: Expired due to Term

• Current Assignee: Nissan Motor Co., Ltd.
• Original Assignee: Nissan Motor Co., Ltd.
• Inventors: Shimizu, Kouichi
• Primary Examiner(s): Chin, Gary
• Application Number:
  US09/346,302
• Time in Patent Office: 536 Days
• Field of Search: 701/1, 701/70, 701/71, 701/72, 701/74, 701/75, 701/76, 180/197, 303/159, 702/145, 702/146, 702/148, 702/56
• US Class Current: 701/1
• CPC Class Codes: B60T 2250/04 Vehicle reference speed; Vehicle body speed
• CPC Class Codes: B60T 8/171 Detecting parameters used in the regulation; Measuring values used in the regulation
• CPC Class Codes: G01P 11/02 Measuring average speed of number of bodies, e.g. of vehicles for traffic control
• CPC Class Codes: G01P 21/02 of speedometers

Abstract

A vehicle velocity detecting device is provided for detecting vehicle velocity of a vehicle. In the device, an average of driving wheels'"'"' speeds Vw_Dave and an acceleration/deceleration V'"'"'w_i of each wheel are calculated. When the average Vw_Dave is less than a designated high wheel speed Vw_Hi of 20 km/h or so and at least one of driving wheels'"'"' acceleration/deceleration V'"'"'w_DL and V'"'"'w_DR is more than a designated low-frequency noise value V'"'"'w_LO of 1G or so, the third wheel speed Vw_3rd from the largest wheel speed is set as the vehicle velocity V_SP. When three or more acceleration/deceleration V'"'"'w_i are together more than a designated high-frequency noise value V'"'"'w_Hi of 5G or so, the wheel speed detected in the past is set as the vehicle velocity V_SP. In either case, the vehicle velocity detecting method by the device is not withdrawn unless the wheel speed Vw_i is less than a designated high wheel speed Vw_LO or unless the average Vw_Dave is more than the designated high wheel speed Vw_Hi and the acceleration/deceleration V'"'"'w_i is less than the designated high-frequency noise value V'"'"'w_Hi.

Claims

1. A vehicle velocity detecting device for detecting vehicle velocity of a vehicle by using respective wheel speeds of at least four wheels of the vehicle, the vehicle velocity detecting device comprising:

a wheel speed detecting unit for detecting the wheel speeds of the four wheels individually;

a noise condition detecting unit for detecting noise condition affecting the wheel speeds detected by the wheel speed detecting unit; and

a vehicle velocity detecting unit for detecting the vehicle velocity corresponding to the noise condition detected by the noise condition detecting unit;

wherein the vehicle velocity detecting unit adopts the third wheel speed of the four wheel speeds from the largest wheel speed as the vehicle velocity when it is judged that the noise condition detected by the noise condition detecting unit affects either one or both of wheel speeds of two driving wheels related to driving force of the vehicle.

2. The vehicle velocity detecting device of claim 1, wherein the noise condition detecting unit operates to detect the noise condition corresponding to acceleration or deceleration in rotation of the respective wheels for the vehicle.

3. A vehicle velocity detecting device for detecting vehicle velocity of a vehicle by using respective wheel speeds of at least four wheels of the vehicle, the vehicle velocity detecting device comprising:

a first means for detecting the wheel speeds of the four wheels individually;

a second means for detecting noise condition affecting the wheel speeds detected by the first means; and

a third means for detecting the vehicle velocity corresponding to the noise condition detected by the second means;

wherein the third means adopts the third wheel speed of the four wheel speeds from the largest wheel speed as the vehicle velocity when it is judged that the noise condition detected by the second means affects either one or both of wheel speeds of two driving wheels related to driving force of the vehicle.