Vehicle dynamics behavior reproduction system

• US 7,184,868 B2
• Filed: 03/25/2004
• Issued: 02/27/2007
• Est. Priority Date: 01/14/2004
• Status: Expired due to Fees

• Current Assignee: Mitsubishi Denki Kabushiki Kaisha (Mitsubishi Electric Corporation)
• Original Assignee: Mitsubishi Denki Kabushiki Kaisha (Mitsubishi Electric Corporation)
• Inventors: Matsunaga, Takanori, Hiemer, Marcus
• Primary Examiner(s): ARTHUR JEANGLAUDE, GERTRUDE
• Application Number:
  US10/808,308
• Publication Number:
  US 20050154513A1
• Time in Patent Office: 1,069 Days
• Field of Search: 701/1, 701 36- 41, 701 70- 72, 701 80- 82, 303146-150, 702148-150
• US Class Current: 701/38
• CPC Class Codes: B60T 8/1725 Using tyre sensors, e.g. Sidewall Torsion sensors [SWT] for tyre pressure and temperature detection B60C23/00
• CPC Class Codes: B60W 2040/1307 Load distribution on each wheel suspension
• CPC Class Codes: B60W 2050/0013 Optimal controllers
• CPC Class Codes: B60W 2050/0031 Mathematical model of the vehicle
• CPC Class Codes: B60W 2520/14 Yaw
• CPC Class Codes: B60W 2530/20 Tyre data
• CPC Class Codes: B60W 2720/14 Yaw
• CPC Class Codes: B60W 30/045 Improving turning performance
• CPC Class Codes: B60W 40/101 Side slip angle of tyre
• CPC Class Codes: B60W 40/103 Side slip angle of vehicle body

Abstract

A vehicle dynamics behavior reproduction system capable of describing accurately behavior of a motor vehicle in a lateral direction even for nonlinear driving situation includes a vertical wheel force arithmetic module (105), a lateral wheel force arithmetic module (110), a cornering stiffness adaptation module (115), a state space model/observer unit (120), a selector (130), a delay module (135), and a tire side slip angle arithmetic module (125). Vertical wheel forces (FZ_ij) and tire side slip angles (α_ij) are determined by using sensor information and estimated values while lateral wheel forces (FY_ij) are determined in accordance with a relatively simple nonlinear approximation equation. The lateral wheel force (FY_ij) and the tire side slip angle (α_ij) provide bases for adaptation of cornering stiffnesses at individual wheels. Vehicle motion is accurately described to a marginal stability by using adapted cornering stiffnesses (C_ij) and other information.

Claims

1. A vehicle dynamics behavior reproduction system for adapting cornering stiffness to driving situation of a motor vehicle in order to describe accurately behavior of the motor vehicle on the basis of various information derived from outputs of on-vehicle sensors without being influenced by said driving situation of the motor vehicle, comprising:

vertical wheel force arithmetic means for arithmetically determining a load applied to each of wheels of said motor vehicle as a vertical wheel force;

lateral wheel force arithmetic means for arithmetically determining a lateral wheel force acting on each of said wheels;

cornering stiffness adaptation means for effectuating adaptation of the cornering stiffness at each of said wheels to said driving situation;

a state space model/observer unit for determining solutions of simultaneous differential equations relating to a dynamics theory of the motor vehicle for calculating variables involved in said dynamics theory;

a selector for selecting a specific signal as required from signals representing said solutions generated by said state space model/observer unit;

delay means for delaying said specific signal on a predetermined unitary time basis; and

tire side slip angle arithmetic means for arithmetically determining a tire side slip angle at each of said wheels in view of said driving situation,

wherein said state space model/observer unit includes a state space observer designed for determining variables which can not straightforwardly be measured.

2. A vehicle dynamics behavior reproduction system according to claim 1, wherein said lateral wheel force arithmetic means is designed to approximate the lateral force F_Y at each of said wheels in accordance with

3. A vehicle dynamics behavior reproduction system according to claim 1, wherein said cornering stiffness adaptation means is designed to effectuate adaptation of the cornering stiffnesses of the individual wheels, respectively, to the driving situation on a predetermined unitary time basis in accordance with an undermentioned adaptation equation:

4. A vehicle dynamics behavior reproduction system according to claim 1, wherein:

the state space model/observer unit comprises a state space model including the differential equations relating to the dynamics theory of the motor vehicle; and

the state space model/observer unit adjusts the parameters of the state space model so that a difference between a calculated yaw rate value and a detected yaw rate sensor value becomes zero.

5. A vehicle dynamics behavior reproduction system according to claim 1, wherein:

the state space model/observer unit comprises a state space model including the differential equations relating to the dynamics theory of the motor vehicle;

the state space model determines the solutions of the differential equations relating to the dynamics theory of the motor vehicle as state space vectors; and

the state space vectors comprise values for vehicle speed, vehicle body side slip angle and a calculated yaw rate value.

6. A vehicle dynamics behavior reproduction system according to claim 1, wherein the specific signal is a vehicle body side slip angle.

7. A vehicle dynamics behavior reproduction system according to claim 1, wherein the variables which can not straightforwardly be measured include a vehicle body side slip angle.

8. A vehicle dynamics behavior reproduction system according to claim 7, wherein the specific signal is also the vehicle body side slip angle.

9. A vehicle dynamics behavior reproduction system for adapting cornering stiffness to driving situation of a motor vehicle in order to describe accurately behavior of the motor vehicle on the basis of various information derived from outputs of on-vehicle sensors without being influenced by said driving situation of the motor vehicle, comprising:

a vertical wheel force arithmetic module that arithmetically determines a load applied to each of wheels of said motor vehicle as a vertical wheel force;

a lateral wheel force arithmetic module that arithmetically determines a lateral wheel force acting on each of said wheels;

a cornering stiffness adaptation module that effectuates adaptation of the cornering stiffness at each of said wheels to said driving situation;

a state space model/observer module that determines solutions of simultaneous differential equations relating to a dynamics theory of the motor vehicle for calculating variables involved in said dynamics theory;

a selector module that selects a specific signal as required from signals representing said solutions generated by said state space model/observer module;

a delay module that delays said specific signal on a predetermined unitary time basis; and

a tire side slip angle arithmetic module that arithmetically determines a tire side slip angle at each of said wheels in view of said driving situation,

wherein said state space model/observer module includes a state space observer designed for determining variables which can not straightforwardly be measured.

10. A vehicle dynamics behavior reproduction system according to claim 9, wherein said lateral wheel force arithmetic module is designed to approximate the lateral force F_Y at each of said wheels in accordance with

11. A vehicle dynamics behavior reproduction system according to claim 9, wherein said cornering stiffness adaptation module is designed to effectuate adaptation of the cornering stiffnesses of the individual wheels, respectively, to the driving situation on a predetermined unitary time basis in accordance with an undermentioned adaptation equation:

12. A vehicle dynamics behavior reproduction system according to claim 9, wherein:

the state space model/observer module comprises a state space model including the differential equations relating to the dynamics theory of the motor vehicle; and

the state space model/observer module adjusts the parameters of the state space model so that a difference between a calculated yaw rate value and a detected yaw rate sensor value becomes zero.

13. A vehicle dynamics behavior reproduction system according to claim 9, wherein:

the state space model/observer module comprises a state space model including the differential equations relating to the dynamics theory of the motor vehicle;

the state space model determines the solutions of the differential equations relating to the dynamics theory of the motor vehicle as state space vectors; and

the state space vectors comprise values for vehicle speed, vehicle body side slip angle and a calculated yaw rate value.

14. A vehicle dynamics behavior reproduction system according to claim 9, wherein the specific signal is a vehicle body side slip angle.

15. A vehicle dynamics behavior reproduction system according to claim 9, wherein the variables which can not straightforwardly be measured include a vehicle body side slip angle.

16. A vehicle dynamics behavior reproduction system according to claim 15, wherein the specific signal is also the vehicle body side slip angle.