Vehicle control apparatus

• US 5,321,616 A
• Filed: 08/07/1991
• Issued: 06/14/1994
• Est. Priority Date: 08/10/1990
• Status: Expired due to Term

• Current Assignee: Matsushita Electric Industrial Company Limited (Panasonic Holdings Corporation)
• Original Assignee: Matsushita Electric Industrial Company Limited (Panasonic Holdings Corporation)
• Inventors: Takigawa, Masuo, Okuda, Eiichiro
• Primary Examiner(s): Black, Thomas G.
• Assistant Examiner(s): Wieland, Susan
• Application Number:
  US07/741,865
• Time in Patent Office: 1,042 Days
• Field of Search: 280/707, 364/424.05, 364/424.01
• US Class Current: 701/37
• CPC Class Codes: B60G 17/0163 the control involving steering geometry, e.g. four-wheel steering
• CPC Class Codes: B60G 2400/204 Vehicle speed
• CPC Class Codes: B60G 2400/40 Steering conditions
• CPC Class Codes: B60G 2400/412 of steering wheel or column
• CPC Class Codes: B60G 2400/82 Ground surface
• CPC Class Codes: B60G 2400/842 Temperature
• CPC Class Codes: B60G 2500/10 Damping action or damper
• CPC Class Codes: B60G 2500/40 Steering
• CPC Class Codes: B60G 2600/604 low pass
• CPC Class Codes: B60G 2800/012 Rolling condition
• CPC Class Codes: B60G 2800/014 Pitch; Nose dive
• CPC Class Codes: B60G 2800/24 Steering, cornering
• CPC Class Codes: B60T 2250/062 loosing zero-point calibration of yaw rate sensors when travelling on banked roads or in case of temperature variations
• CPC Class Codes: B62D 7/159 characterised by computing methods or stabilisation processes or systems, e.g. responding to yaw rate, lateral wind, load, road condition

Abstract

A vehicle behavior during driving is correctly grasped by computing and map-retrieving from output signal (ωy) of an angular velocity sensor (2) for detecting the angular velocity of the vehicle (11). A vehicle control apparatus of the present invention can correctly compensate the output signal (ωy) having error owing to the secular change or temperature change, etc. by using a zero-point calculation means (6, 16, 26, 36, 46, 56) for calculating zero-point signal (ωy0) and an angular velocity correction means (7, 17, 27, 37, 47, 57) for correcting the output signal (ωy) of the angular velocity sensor (2).

Claims

1. A vehicle control apparatus comprising:

a vehicle speed sensor for detecting speed of a vehicle;

at least one angular velocity sensor for detecting angular velocity about a pitch axis, a yaw axis or a roll axis of said vehicle;

a zero-point calculation means which detects a normal state of said vehicle by using output signals of said vehicle speed sensor and output signals of said angular velocity sensor, and which calculates an average of said output signals of said angular velocity sensor in said normal state, said average of said output signals of said angular velocity sensor corresponding to a zero-point signal;

an angular velocity correction means which corrects said output signal of said angular velocity sensor by using said zero-point signal calculated by said zero-point calculation means;

a turning state inference means which infers a rolling state of said vehicle from said corrected signal output from said angular velocity correction means and an output signal of said vehicle speed sensor, and further produces output signals for controlling said rolling state of said vehicle; and

shock absorber means whereof a damping force is adjusted in response to said output signals from said turning state inference means.

2. A vehicle control apparatus in accordance with claim 1, wherein

said zero-point calculation means which comprises a low-pass filter having a predetermined cut-off frequency eliminates signals which is output by said angular velocity sensor owing to the rolling and the vibrating of said vehicle;

and

said angular velocity correction means corrects output signal of said angular velocity sensor during driving.

3. A vehicle control apparatus in accordance with claim 1, wherein

said zero-point calculation means calculates a zero-point signal of said angular velocity sensor when a change rate of the detected angular velocity is on or below a predetermined change rate.

4. A vehicle control apparatus in accordance with claim 1, wherein

said zero-point calculation means which infers a drift value and a zero-point signal from a change rate of the detected angular velocity;

and

said angular velocity correction means corrects output signal of said angular velocity sensor regardless of driving.

5. A vehicle control apparatus comprising:

a vehicle speed sensor for detecting speed of a vehicle;

a steering wheel angle sensor for detecting steering angle of a steering wheel of said vehicle;

an angular velocity sensor for detecting angular velocity about a yaw axis of said vehicle;

a rear wheel steering unit for steering rear wheels; and

a four-wheel steering unit which comprises;

(a) a zero-point calculation means which detects a normal state of said vehicle by using output signals of said vehicle speed sensor and output signals of said angular velocity sensor, and which calculates an average of said output signals of said angular velocity sensor in said normal state, said calculated average corresponding to a zero-point signal;

(b) an angular velocity correction means which corrects said output signal of said angular velocity sensor by said zero-point signal calculated by said zero-point calculation means; and

(c) a rear wheel decision means for deciding a target steer angle of said rear wheels in response to corrected value corrected by said angular velocity correction means, output signals of said vehicle speed sensor and output signals of said steering wheel angle sensor.

6. A vehicle control apparatus in accordance with claim 5, wherein

said zero-point calculation means which infers a drift value and a zero-point signal from a change rate of the detected angular velocity;

and

said angular velocity correction means corrects output signal of said angular velocity sensor regardless of driving.

7. A vehicle control apparatus in accordance with claim 5, wherein

said zero-point calculation means which comprises a low-pass filter having a predetermined cut-off frequency eliminates signals which is output by said angular velocity sensor owing to the rolling and the vibrating of said vehicle;

and

said angular velocity correction means corrects output signal of said angular velocity sensor during driving.

8. A vehicle control apparatus in accordance with claim 5, wherein

said zero-point calculation means calculates a zero-point signal of said angular velocity sensor when an output signal of said steering wheel angle sensor is on or below a predetermined value, and when a change rate of the detected angular velocity is on or below a predetermined change rate.