Method of estimating quantities that represent state of vehicle

• US 20030093190A1
• Filed: 11/06/2002
• Published: 05/15/2003
• Est. Priority Date: 11/15/2001
• Status: Active Grant

• Current Assignee: Honda Giken Kogyo Kabushiki Kaisha (Honda Motor Company)
• Original Assignee: Honda Giken Kogyo Kabushiki Kaisha (Honda Motor Company)
• Inventors: Mori, Atsushi
• Granted Patent: US 6,745,112 B2
• Time in Patent Office: Days
• US Class Current: 701/1
• CPC Class Codes: B60G 17/019 characterised by the type of sensor or the arrangement thereof B60G17/01941 takes precedence
• CPC Class Codes: B60G 17/0195 characterised by the regulation being combined with other vehicle control systems conjoint control of vehicle sub-units including control of suspension systems B60W10/22
• CPC Class Codes: B60G 2400/0523 Yaw rate
• CPC Class Codes: B60G 2400/104 lateral or transversal with regard to vehicle
• CPC Class Codes: B60G 2400/204 Vehicle speed
• CPC Class Codes: B60G 2400/30 Propulsion unit conditions
• CPC Class Codes: B60G 2400/41 Steering angle
• CPC Class Codes: B60G 2600/02 Retarders, delaying means, dead zones, threshold values, cut-off frequency, timer interruption
• CPC Class Codes: B60G 2800/212 Transversal; Side-slip during cornering
• CPC Class Codes: B60G 2800/702 Improving accuracy of a sensor signal
• CPC Class Codes: B60G 2800/95 Automatic Traction or Slip Control [ATC]
• CPC Class Codes: B60G 2800/952 Electronic driving torque distribution
• CPC Class Codes: B60G 2800/96 ASC - Assisted or power Steering control
• CPC Class Codes: B60T 2230/02 Side slip angle, attitude angle, floating angle, drift angle
• CPC Class Codes: B60T 8/172 Determining control parameters used in the regulation, e.g. by calculations involving measured or detected parameters B60T8/17551 takes precedence
• CPC Class Codes: B60W 2050/0033 Single-track, 2D vehicle model, i.e. two-wheel bicycle model
• CPC Class Codes: B60W 2510/0657 Engine torque
• CPC Class Codes: B60W 2510/20 Steering systems
• CPC Class Codes: B60W 2520/10 Longitudinal speed
• CPC Class Codes: B60W 2520/125 Lateral acceleration
• CPC Class Codes: B60W 2520/14 : Yaw
• CPC Class Codes: B60W 2540/18 : Steering angle
• CPC Class Codes: B60W 2710/105 : Output torque
• CPC Class Codes: B60W 2720/403 : between front and rear axle
• CPC Class Codes: B60W 30/02 : Control of vehicle driving stability
• CPC Class Codes: B60W 40/101 : Side slip angle of tyre

Abstract

The precision of the estimations of the vehicle body sideslip angle and the values related to the vehicle body sideslip angle can be improved by a simple and inexpensive method. The improved method of estimating quantities that represent the vehicle state of a vehicle comprises the steps of detecting a yaw rate and vehicle speed and calculating a vehicle body sideslip angle using three equations, which comprises an equation of equilibrium for the force in the lateral direction of the vehicle and an equation of equilibrium for the moment around a vertical axis of the vehicle, and an equation for the physical relationships of the quantities that represent the state of the vehicle movement, and which include a vehicle sideslip angle, a front wheel cornering power, and a rear wheel cornering power as unknown values.

Claims

1. A method of estimating quantities that represent the vehicle state of a vehicle comprises the steps of:

detecting a yaw rate, lateral acceleration and vehicle speed; and

calculating a vehicle body sideslip angle using three equations, comprising an equation of equilibrium for the force in the lateral direction of the vehicle and an equation of equilibrium for the moment around a vertical axis of the vehicle, and an equation for the physical relationships of the quantities that represent the state of the vehicle movement, using a vehicle sideslip angle, a front wheel cornering power, and a rear wheel cornering power as unknown quantities.

2. A method of estimating quantities that represent the state of the vehicle state comprises the steps of:

detecting the yaw rate, the lateral acceleration, and the vehicle speed;

calculating a vehicle speed in the lateral direction using three equations, comprising an equation of equilibrium for the force in the lateral direction of the vehicle and an equation of equilibrium for the moment around a vertical axis of the vehicle, and an equation for the physical relationships of the quantities that represent the state of the vehicle movement, using a vehicle speed in the lateral direction, a front wheel cornering power, and a rear wheel cornering power as unknown quantities; and

calculating the vehicle body sideslip angle from said vehicle speed in the lateral direction.

3. A method of estimating quantities that represent the state of a vehicle comprising the steps of:

detecting the yaw rate, the lateral acceleration, and the vehicle speed; and

calculating a vehicle body sideslip angle using three equations, comprising an equation of equilibrium for the force in the lateral direction of the vehicle and an equation of equilibrium for the moment around a vertical axis of the vehicle, and an equation for the physical relationships of the quantities that represent the state of the vehicle movement, using a vehicle sideslip angle, a front wheel tire lateral force, and a rear wheel tire lateral force as unknown quantities.

4. A method of estimating quantities that represent the state of a vehicle comprising the steps of:

detecting the yaw rate, the lateral acceleration, and the vehicle speed; and

calculating the values related to the vehicle sideslip angle using three equations comprising an equation of equilibrium for the force in the lateral direction of the vehicle and an equation of equilibrium for the moment around a vertical axis of the vehicle, and an equation for the physical relationships of the quantities that represent the state of the vehicle movement using a variable related to the vehicle body sideslip angle and a variable that determine the characteristics of the front wheel tires, and a variable that determine the characteristics of the rear wheel tires as unknowns.

5. A method of estimating the quantities that represent the state of the vehicle according to claim 4 comprising the steps of:

calculating differential values of the values related to said vehicle sideslip angle based on said yaw rate and said vehicle speed; and

testing the differential value of the values related to said vehicle body sideslip angle by said lateral acceleration.

6. A method of estimating the quantities that represent the state of a vehicle according to claim 5 comprising the steps of:

calculating the values related to said vehicle body sideslip angle by integrating the differential values of said values related to the vehicle body sideslip angle; and

calculating the differential values of the said values related to the vehicle sideslip angle in the present processing by using said values related to the vehicle sideslip angle calculated in the previous processing.

7. A method of estimating the quantities that represent the state of a vehicle according to claim 4 comprising the steps of:

eliminating either one of said variable that determines the characteristics of the front wheel tires or said variable that determines the characteristics of the rear wheel tires from said equation of equilibrium for the force in the lateral direction of the vehicle and said equation of equilibrium for the moment around a vertical axis of the vehicle.

8. A method for estimating the quantities representing the state of a vehicle according to claim 7 comprising the steps of:

calculating the differential values of said values related to the vehicle body sideslip angle by providing initial values to either said variable that determine the characteristics of the front wheel tires or said variables that determine the characteristics of the rear wheel tires, whichever has not been eliminated;

calculating the lateral acceleration from an equation for the physical relationships that represent said state of the vehicle movement using the differential values of said values related to the vehicle sideslip angle; and

updating said initial values based on the results of comparing said calculated lateral acceleration and said detected lateral acceleration.