DECELERATION CONTROL APPARATUS FOR MOTOR VEHICLE

• US 20140121928A1
• Filed: 10/24/2013
• Published: 05/01/2014
• Est. Priority Date: 10/25/2012
• Status: Active Grant

• Current Assignee: DENSO Corporation
• Original Assignee: DENSO Corporation
• Inventors: Namikiri, Tatsuya, Kurumisawa, Jin, Nozawa, Toyohito
• Granted Patent: US 9,434,363 B2
• Time in Patent Office: Days
• US Class Current: 701/70
• CPC Class Codes: B60T 2201/16 Curve braking control, e.g. turn control within ABS control algorithm
• 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

Abstract

When a vehicle runs along a curved path, successive values of a speed limit are calculated based on the yaw rate of the vehicle, and values of acceleration demand are calculated and applied to control the actual vehicle speed based on the speed limit. If commencement of oscillation of the yaw rate and acceleration demand is detected, due to running along the curved path, guard processing is applied to the values of speed limit used to calculate the acceleration demand or is applied to the acceleration demand, such as to prevent the acceleration demand from varying in a direction that would increase the speed limit. Instability of deceleration control due to the oscillation is thereby substantially suppressed.

Claims

1. A deceleration control apparatus for installation on a vehicle, for executing deceleration control based on running conditions of the vehicle including a turning state of the vehicle, said deceleration control apparatus including

turning state acquisition circuitry configured for acquiring successive values of a turning state quantity indicative of said turning state, and

control value acquisition circuitry configured for deriving successive values of a control quantity for use in executing said deceleration control, the control quantity values being respectively derived based on said acquired values of the turning state quantity;

wherein said deceleration control apparatus comprises guard processing circuitry configured for executing guard processing during execution of said deceleration control, said guard processing comprising;

detecting oscillation, of said acquired turning state quantity or of said control quantity when said oscillation occurs due to said vehicle running in a special running condition, and

when said oscillation is detected, establishing a guard value of said turning state quantity or a guard value of said control quantity, and executing said deceleration control based upon said guard value of said control quantity or upon a value of said control quantity derived from said guard value of the turning state quantity, in place of said successively derived values of the control quantity

2. The deceleration control apparatus as claimed in claim 1, wherein:

during execution of said deceleration control, successive values of a speed limit are derived in accordance with said successive values of said turning state quantity, and successive values of said control quantity are derived based on said values of speed limit; and

execution of said guard processing prevents increase of said vehicle speed, by preventing variation of said speed limit in a direction of increase.

3. The deceleration control apparatus as claimed in claim 2, wherein said special running condition is a condition of running along a curved section of a travel path.

4. The deceleration control apparatus as claimed in claim 3, wherein said turning state acquisition circuitry is further configured to obtain successive values of lateral acceleration of said vehicle, and wherein said guard processing circuitry is configured to initiate said guard processing when an absolute value of said lateral acceleration exceeds a first predetermined threshold.

5. The deceleration control apparatus as claimed in claim 4, wherein said guard processing circuitry is configured to terminate said guard processing when successively obtained absolute values of said lateral acceleration have remained below a second predetermined threshold for longer than a predetermined continuation interval.

6. The deceleration control apparatus as claimed in claim 4 wherein said turning state quantity comprises a yaw rate of said vehicle.

7. The deceleration control apparatus as claimed in claim 6, comprising a yaw rate sensor, wherein values of said yaw rate are detected by said yaw rate sensor.

8. The deceleration control apparatus as claimed in claim 7 comprising a vehicle speed sensor, wherein values of said lateral acceleration are calculated based on said detected values of yaw rate in conjunction with values of vehicle speed detected by said vehicle speed sensor.

9. The deceleration control apparatus as claimed in claim 6, wherein said control quantity comprises an acceleration demand and wherein said deceleration control apparatus is operable for determining a speed of said vehicle by selectively effecting acceleration and deceleration of said vehicle in accordance with said acceleration demand.

10. The deceleration control apparatus as claimed in claim 9 wherein said acceleration demand is calculated based on a difference between an actual speed of said vehicle and said speed limit and wherein:

while a guard value of yaw rate is not established, successive values of said speed limit are derived based on successively acquired values of yaw rate; and

while a guard value of yaw rate is established, a value of said speed limit is derived based upon said guard value.

11. The deceleration control apparatus as claimed in claim 10 wherein said guard processing circuitry is configured to:

detect a first time point as a time point at which said successively acquired values of lateral acceleration begin to decrease after exceeding a predetermined threshold value thereof, and

establish a guard value of said yaw rate as a value of said yaw rate acquired at said first time point, and apply said guard value of yaw rate to derive a value of said speed limit;

and wherein prior to said first time point, said successively acquired values of yaw rate are applied in deriving successive values of said speed limit.