VEHICLE CONTROL DEVICE, AND VEHICLE CONTROL METHOD

• US 20150039199A1
• Filed: 04/08/2013
• Published: 02/05/2015
• Est. Priority Date: 05/14/2012
• Status: Active Grant

• Current Assignee: Nissan Motor Co., Ltd.
• Original Assignee: Nissan Motor Co., Ltd.
• Inventors: Kikuchi, Hironobu
• Granted Patent: US 9,156,452 B2
• Time in Patent Office: Days
• US Class Current: 701/70
• CPC Class Codes: B60G 17/0164 mainly during accelerating or braking
• CPC Class Codes: B60G 2800/014 Pitch; Nose dive
• CPC Class Codes: B60T 2230/04 Jerk, soft-stop; Anti-jerk, reduction of pitch or nose-dive when braking
• CPC Class Codes: B60T 2260/06 Active Suspension System
• CPC Class Codes: B60T 8/1755 Brake regulation specially adapted to control the stability of the vehicle, e.g. taking into account yaw rate or transverse acceleration in a curve road vehicle drive control systems for control of driving stability otherwise than by controlling a particular sub-unit B60W30/02
• CPC Class Codes: B60T 8/17555 specially adapted for enhancing driver or passenger comfort, e.g. soft intervention or pre-actuation strategies

Abstract

A vehicle control device includes a sensor and a controller. The sensor detects wheel speed. The controller estimates an amount of pitch motion made by a vehicle based on information in a prescribed frequency range of wheel speed detected by the sensor. The controller control friction brakes so as to bring the pitch motion amount to a target pitch motion amount, as well as gradually lowering an amount by which the friction brakes are controlled, in instances where an estimation accuracy of the pitch motion amount deteriorates.

Claims

1. A vehicle control device comprising:

a plurality of friction brakes for sprung mass vibration damping control;

at least one wheel speed sensor that detects wheel speed;

a sprung mass state estimating unit that estimates a sprung mass state based on information in a prescribed frequency range of wheel speed detected by the wheel speed sensor;

a friction brake orientation control unit that calculates a braking torque control amount for the friction brakes to bring the sprung mass state estimated by the sprung mass state estimating unit to a target sprung mass state, and the friction brake orientation control unit outputting the braking torque control amount to the friction brakes;

an estimation accuracy deterioration detection unit that detects means deterioration of estimation accuracy of a sprung mass state estimated by the sprung mass state estimating unit; and

a deterioration friction brake orientation accuracy control unit that lowers the braking torque control amount, in cases in which deterioration of estimation accuracy has been detected by the estimation accuracy deterioration detection unit;

the friction brake orientation control unit minimizing pitch motion of the vehicle; and

the deterioration friction brake orientation accuracy control unit gradually lowering the braking torque control amount prevailing immediately prior to a time that deterioration of estimation accuracy was detected.

2. The vehicle control device according to claim 1, wherein

the deterioration friction brake orientation accuracy control unit, over a prescribed transition time, lowers to zero the braking torque control amount prevailing immediately prior to the time that deterioration of estimation accuracy was detected.

3. The vehicle control device according to claim 2, wherein

the deterioration friction brake orientation accuracy control unit sets the prescribed transition time to a time equivalent to the frequency of the sprung mass resonance frequency or less.

4. A vehicle control device comprising:

a sensor for detecting wheel speed; and

a controller that estimates an amount of pitch motion made by a vehicle based on information in a prescribed frequency range of wheel speed detected by the sensor, and that controls friction brakes so as to bring the pitch motion amount to a target pitch motion amount, as well as gradually lowering an amount by which the friction brakes are controlled, in instances where an estimation accuracy of the pitch motion amount deteriorates.

5. A control method for controlling a vehicle, the method comprising:

detecting wheel speed using a sensor of the vehicle;

estimating, using a control device, a pitch motion amount based on information in a prescribed frequency range of wheel speed detected by the sensor;

controlling, using the control device, a friction brake so as to bring the pitch motion amount to a target pitch motion amount; and

gradually lowering an amount by which the friction brakes are controlled, in instances where an estimation accuracy of the pitch motion amount deteriorates.