Method of setting parameter in method of detecting decreased pneumatic pressure

• US 8,032,344 B2
• Filed: 03/25/2010
• Issued: 10/04/2011
• Est. Priority Date: 02/14/2008
• Status: Expired due to Fees

• Current Assignee: Sumitomo Rubber Industries Limited
• Original Assignee: Sumitomo Rubber Industries Limited
• Inventors: Miyamoto, Kazuyoshi
• Primary Examiner(s): Shah; Kamini S
• Assistant Examiner(s): DAY, HERNG DER
• Application Number:
  US12/731,689
• Publication Number:
  US 20100179796A1
• Time in Patent Office: 558 Days
• Field of Search: 703/6, 703/8, 701/29, 340/442, 340/443, 340/444
• US Class Current: 703/8
• CPC Class Codes: B60C 23/061 by monitoring wheel speed measuring distance traversed on the ground by vehicles G01C22/00

Abstract

A method of setting a parameter in a method of detecting a decreased tire air pressure for detecting a decreased tire air pressure based on a wheel rotational speed obtained from tires attached to a four-wheel driving vehicle. The method includes a vehicle model preparation step of preparing a vehicle model including a suspension member; a tire model preparation step of preparing a tire model; a step of inputting a friction coefficient between a tire and a road surface; and a simulation step of performing a running simulation of the vehicle model attached with the tire model. A determination parameter for determining whether the tire has a decreased air pressure or not is set based on wheel rotational speeds of the tires of the respective four wheels obtained in the simulation step.

Claims

1. A method of setting a parameter in a method of detecting a decreased tire air pressure for detecting a decreased tire air pressure based on a wheel rotational speed obtained from tires attached to a four-wheel driving vehicle, comprising:

a vehicle model preparation step of preparing a vehicle model including a suspension member;

a tire model preparation step of preparing a tire model;

a step of inputting a friction coefficient between a tire and a road surface; and

a simulation step of performing a running simulation of the vehicle model attached with the tire model,

wherein a determination parameter for determining whether the tire has a decreased air pressure or not is set based on wheel rotational speeds of the tires of the respective four wheels obtained in the simulation step,

the wheel rotation speed is obtained in consideration of at least the slip between the tire and a road surface and a change of a tire radius by an application of a load,

the simulation step further calculates, based on the wheel rotational speed, a parameter for determining the use of different tires for determining that tires having different characteristics are attached to the vehicle, and

the accuracy of the parameter for determining the use of different tires is checked by simulating the running of the vehicle on a climbing course and the running of the vehicle while pulling a trailer.

2. The method of setting a parameter in a method of detecting a decreased tire air pressure according to claim 1, wherein the tire model is prepared based on tire characteristic values including a front-and-rear force, a lateral force, an aligning moment, and a camber thrust of the tires.

3. The method of setting a parameter in a method of detecting a decreased tire air pressure according to claim 1, wherein the vehicle model is prepared based on vehicle characteristic values including a vehicle gravity center, a vehicle inertia moment, a wheel base length, respective track widths of front and rear wheels of the vehicle, a vehicle weight, a spring characteristic of a suspension, a damper attenuation characteristic, and a roll center height.

4. The method of setting a parameter in a method of detecting a decreased tire air pressure according to claim 3, wherein the tire model is prepared based on tire characteristic values including a front-and-rear force, a lateral force, an aligning moment, and a camber thrust of the tires.

5. A method of setting an alarm threshold in a method of detecting a decreased tire air pressure for detecting a decreased tire air pressure based on a wheel rotational speed obtained from tires attached to a four-wheel driving vehicle, comprising:

a vehicle model preparation step of preparing a vehicle model including a suspension member;

a tire model preparation step of preparing a tire model that can at least represent characteristics of a tire front-and-rear force at a normal internal pressure and a decreased pressure;

a step of inputting a friction coefficient between a tire and a road surface;

a step of inputting data representing an air resistance generated in the vehicle when the vehicle is running, the data including a vehicle frontal projected area, a reference point upon which an aerodynamic force acts, an air drag coefficient, and an air lift force coefficient; and

a simulation step of performing a running simulation of the vehicle model attached with the tire model,

wherein the simulation step is performed by a site or a server exterior to the four-wheel driving vehicle,

the vehicle model and the tire model are prepared with the use of the vehicle data and the tire characteristic data that are selected based on information including vehicle name, the brand of the tires attached to the vehicle and the tire size inputted through an input means installed in an in-vehicle computer of the four-wheel driving vehicle, and

an alarm threshold for determining whether a driving wheel tire has a decreased air pressure or not is set at a site of the server, based on the wheel rotational speeds of the tires of the respective four wheels obtained in the simulation step.

6. The method of setting a parameter in a method of detecting a decreased tire air pressure according to claim 5, wherein the vehicle model is prepared based on vehicle characteristic values including a vehicle gravity center, a vehicle inertia moment, a wheel base length, respective track widths of front and rear wheels of the vehicle, a vehicle weight, a spring characteristic of a suspension, a damper attenuation characteristic, and a roll center height.