Vehicle motion control device

• US 20050027426A1
• Filed: 07/27/2004
• Published: 02/03/2005
• Est. Priority Date: 07/30/2003
• Status: Active Grant

• Current Assignee: Advics Company Limited (Aisin Corp.)
• Original Assignee: Advics Company Limited (Aisin Corp.)
• Inventors: Kato, Toshihisa, Nagaya, Junya, Tsugawa, Shinji
• Granted Patent: US 7,392,127 B2
• Time in Patent Office: Days
• US Class Current: 701/70
• CPC Class Codes: B60G 2800/0124 Roll-over conditions
• CPC Class Codes: B60G 2800/215 by applying a braking action on each wheel individually
• CPC Class Codes: B60G 2800/85 System Prioritisation
• CPC Class Codes: B60G 2800/922 EBV - Electronic brake force distribution
• CPC Class Codes: B60G 2800/952 Electronic driving torque distribution
• CPC Class Codes: B60T 2230/03 Overturn, rollover
• CPC Class Codes: B60T 8/17554 specially adapted for enhancing stability around the vehicles longitudinal axle, i.e. roll-over prevention road vehicle drive control systems for roll-over prevention otherwise than by controlling a particular sub-unit B60W30/04
• CPC Class Codes: B60W 10/184 with wheel brakes
• CPC Class Codes: B60W 2030/043 about the roll axis
• CPC Class Codes: B60W 2050/0094 of control units
• CPC Class Codes: B60W 2520/125 Lateral acceleration
• CPC Class Codes: B60W 2710/105 Output torque
• CPC Class Codes: B60W 2720/403 between front and rear axle
• CPC Class Codes: B60W 30/04 related to roll-over prevention
• CPC Class Codes: B60W 30/18172 Preventing, or responsive to skidding of wheels
• CPC Class Codes: B60W 50/035 Bringing the control units into a predefined state, e.g. giving priority to particular actuators

Abstract

The vehicle motion control device of the invention utilizes that the detected lateral acceleration Gyd based upon the output from the lateral acceleration sensor takes a value obtained by adding a value corresponding to the roll angle to the actual lateral acceleration based upon the centrifugal force exerted on the vehicle and that the actual lateral acceleration can accurately be calculated and estimated, as the estimated lateral acceleration Gye, based upon the output from the yaw rate sensor, whereby this device judges that there is a tendency in which an excessive roll angle occurs on the vehicle to thereby execute the predetermined roll-over preventing control, when the increasing speed of the detected lateral acceleration Gyd exceeds the first predetermined value and the increasing speed of the estimated lateral acceleration Gye becomes smaller than the second predetermined value (<first predetermined value), i.e., when the value of the estimated lateral acceleration Gye is changed from its increasing state to the approximately constant state during when the detected lateral acceleration Gyd increases.

Claims

1. A vehicle motion control device comprising:

estimated lateral acceleration calculating means that obtains a motion state quantity showing a motion state of a vehicle and calculates, based upon the obtained motion state quantity, a lateral acceleration based upon centrifugal force exerted on the vehicle as an estimated lateral acceleration;

a lateral acceleration sensor that obtains a lateral acceleration exerted on the vehicle as a detected lateral acceleration by detecting a value of a component of external force exerted on the vehicle in the side-to-side direction;

excessive roll angle occurrence tendency judging means that judges that there is a tendency in which an excessive roll angle occurs on the vehicle by utilizing that the estimated lateral acceleration is changed from its increasing state to approximately constant state during when the detected lateral acceleration increases; and

specific process executing means that executes a specific process for preventing that the roll angle of the vehicle becomes excessive, when it is judged that there is a tendency in which the excessive roll angle occurs on the vehicle.

2. A vehicle motion control device claimed in claim 1, wherein the estimated lateral acceleration calculating means obtains a yaw rate of the vehicle as the motion state quantity and calculates the estimated lateral acceleration based upon the obtained yaw rate.

3. A vehicle motion control device claimed in claim 1, wherein the excessive roll angle occurrence tendency judging means is configured to judge that there is a tendency in which an excessive roll angle occurs on the vehicle when the increasing speed of the detected lateral acceleration exceeds a first predetermined value and the increasing speed of the estimated lateral acceleration becomes smaller than a second predetermined value that is smaller than the first predetermined value.

4. A vehicle motion control device claimed in claim 1, wherein the excessive roll angle occurrence tendency judging means is configured to calculate a deviation between the detected lateral acceleration and the estimated lateral acceleration as a lateral acceleration deviation and to judge that there is a tendency in which an excessive roll angle occurs on the vehicle based upon the change in the changing speed of the lateral acceleration deviation.

5. A vehicle motion control device claimed in claim 4, wherein the excessive roll angle occurrence tendency judging means is configured to judge that there is a tendency in which an excessive roll angle occurs on the vehicle when the ratio of the change in the changing speed of the lateral acceleration deviation to the change in the lateral acceleration deviation becomes greater than a predetermined reference value.

6. A vehicle motion control device claimed in claim 1, wherein the specific process executing means is configured to execute, as the specific process, a process for exerting braking force for generating a yawing moment on the vehicle in the direction opposite to the turning direction of the vehicle on a predetermined wheel.