METHOD OF ESTIMATING MASS OF VEHICLE

• US 20080126009A1
• Filed: 09/17/2007
• Published: 05/29/2008
• Est. Priority Date: 11/29/2006
• Status: Active Grant

• Current Assignee: Hyundai Motor Company (Hyundai Motor Group)
• Original Assignee: Hyundai Motor Company (Hyundai Motor Group)
• Inventors: Lim, Sung-Hyun, Jung, Jong-Chul, Hong, Dae-Gun, Huh, Kun-Soo
• Granted Patent: US 7,499,826 B2
• Time in Patent Office: Days
• US Class Current: 702/175
• CPC Class Codes: G01G 19/086 wherein the vehicle mass is dynamically estimated

Abstract

A method of estimating a mass of a vehicle. If a yaw rate is smaller than a reference value, a straight direction model algorithm is applied. If a measured speed and a measured steering angle are larger than reference values, a lateral direction model algorithm is applied. If a measured vertical acceleration is larger than a reference value, a vertical direction model algorithm is applied. If each of the estimated masses is in an allowable range, and is constant for a given time period, the masses are applied to a recursive least square method, thereby estimating the mass of the vehicle.

Claims

1. A method of estimating a mass of a vehicle, comprising:

a first step of measuring a yaw rate of the vehicle, a speed of the vehicle, a steering angle of the vehicle, and a vertical acceleration of the vehicle;

a second step of comparing the measured yaw rate to a reference yaw rate, and if the measured yaw rate is smaller than the reference yaw rate, applying a straight direction model algorithm, thereby estimating a second step mass;

a third step of comparing the measured speed to a reference speed, and comparing the measured steering angle to a reference steering angle, and if the measured speed is larger than the reference speed and the measured steering angle is larger than the reference steering angle, applying a lateral direction model algorithm, thereby estimating a third step mass;

a fourth step of comparing the measured vertical acceleration with a reference vertical acceleration, and if the measured vertical acceleration is larger than the reference vertical acceleration, applying a vertical direction model algorithm, thereby estimating a fourth step mass;

a fifth step of, if the second step mass is constant for a fifth step amount of time, determining whether the second step mass is in a range between a minimum mass and a maximum mass;

a sixth step of, if the third step mass is constant for a sixth step amount of time, determining whether the third step mass is in the range between the minimum mass and the maximum mass;

a seventh step of, if the fourth step mass is constant for a seventh step amount of time, determining whether the fourth step mass is in the range between the minimum mass and the maximum mass;

an eighth step of, if each of the second, third, and fourth step masses is in the range, applying the second, third, and fourth step masses to a recursive least square method, thereby estimating the mass of the vehicle; and

a ninth step of inputting the mass of the vehicle to a control unit.

2. The method as defined in claim 1, further comprising returning to the first step if the measured yaw rate is larger than the reference yaw rate, if the measured speed is smaller than the reference speed, if the measured steering angle is smaller than the reference steering angle, of if the measured vertical acceleration is smaller than the reference vertical acceleration.

3. The method as defined in claim 1, further comprising returning to the first step if the second step mass is not constant for the fifth step amount of time, if the third step mass is not constant for the sixth step amount of time, or if the fourth step mass is not constant for the seventh step amount of time.

4. The method as defined in claim 1, wherein the control unit comprises an electronic stability control unit, which performs safety control based on the mass of the vehicle.

5. The method as defined in claim 1, wherein the control unit determines whether a vehicle rollover risk exists based on the mass of the vehicle, and performs safety control based on whether the vehicle rollover risk exists.