Travel characteristic control system for automotive vehicle

• US 5,684,699 A
• Filed: 01/13/1993
• Issued: 11/04/1997
• Est. Priority Date: 01/14/1992
• Status: Expired due to Fees

• Current Assignee: Toyota Jidosha Kabushiki Kaisha (Toyota Motor Corporation)
• Original Assignee: Toyota Jidosha Kabushiki Kaisha (Toyota Motor Corporation)
• Inventors: Sugiyama, Mizuho
• Primary Examiner(s): Teska, Kevin J.
• Assistant Examiner(s): PHAN, THAI Q
• Application Number:
  US08/003,700
• Time in Patent Office: 1,756 Days
• Field of Search: 364/424.01, 364/424.03, 364/424.05, 364/453, 364/423, 364/449, 364/426.03, 364/450, 364/421.01, 364/423.098, 364/424.088, 364/424.087 , 364/424.097, 180/447, 395/24, 395/22, 395/11, 395/905
• US Class Current: 701/41
• CPC Class Codes: B60T 2260/022 Rear-wheel steering; Four-wheel steering
• CPC Class Codes: B60T 8/174 characterised by using special control logic, e.g. fuzzy logic , neural computing
• CPC Class Codes: B60T 8/17551 determining control parameters related to vehicle stability used in the regulation, e.g. by calculations involving measured or detected parameters
• CPC Class Codes: B62D 6/003 in order to control vehicle yaw movement, i.e. around a vertical axis B62D6/007 takes precedence
• CPC Class Codes: B62D 7/159 characterised by computing methods or stabilisation processes or systems, e.g. responding to yaw rate, lateral wind, load, road condition
• CPC Class Codes: F02D 41/1404 Fuzzy logic control
• CPC Class Codes: F02D 41/1405 Neural network control

Abstract

An electric control system for controlling a travel characteristic of an automotive vehicle, wherein a driving condition, movement conditions and a travel course of the vehicle are detected and a number of parameters indicative of a resultant of learning based on a teacher data are memorized, and wherein a neural network is adapted to estimate a characteristic index indicative of a driving characteristic of the driver on a basis of the memorized parameters and the detected driving condition and travel course of the vehicle. In the control system, a control signal for control of the travel characteristic of the vehicle is produced in accordance with the detected movement conditions of the vehicle and corrected in accordance with the estimated characteristic index.

Claims

1. An electric control system for controlling a travel characteristic of an automotive vehicle, comprising:

input means for setting a teacher data indicative of a driver'"'"'s intent to drive;

first detection means for detecting a driving condition of the vehicle;

second detection means for detecting movement conditions of the vehicle;

third detection means for calculating positional change amounts of the vehicle based on the detected movement conditions of the vehicle;

renewal means for renewing a time-series data of the detected driving condition and the calculated positional change amounts at a predetermined time interval and for detecting a travel locus of the vehicle on a basis of the time-series data;

memory means for memorizing a plurality of predetermined parameters;

a neural network for estimating a characteristic index indicative of a driving characteristic of a driver on a basis of the memorized parameters and the time-series data of the detected driving condition and the calculated positional change amounts and for renewing the memorized parameters in such a manner as to minimize a difference between an index defined by the teacher data and the estimated characteristic index;

means for producing a control signal for control of the travel characteristic of the vehicle in accordance with the detected movement conditions of the vehicle; and

correction means for correcting the control signal in accordance with the estimated characteristic index.

2. An electric control system as claimed an claim 1, wherein said first detection means comprises a handle steering angle sensor for detecting a steering angle of a steering handle of the vehicle, an accelerator sensor for detecting a depression angle of an accelerator pedal of the vehicle, a speed sensor for detecting a travel speed of the vehicle, and a brake sensor for detecting a depression angle of a brake pedal of the vehicle.

3. An electric control system as claimed in claim 1, wherein said second detection means comprises a yaw rate sensor for detecting a yaw rate of the vehicle and a speed sensor for detecting a travel speed of the vehicle.

4. An electric control system as claimed in claim 3, wherein said third detection means comprises means for calculating the positional change amounts of the vehicle on an X, Y coordinate based on the yaw rate and travel speed of the vehicle respectively detected by said yaw rate sensor and said speed sensor.

5. An electric control system as claimed in claim 3, wherein said third detection means comprises means for calculating the positional change amounts of the vehicle based on the following equations and indicated on an X, Y coordinate:

space="preserve" listing-type="equation">X=V sin(∫

τ

dt)

space="preserve" listing-type="equation">Y=V cos(∫

τ

dt)

where V is the travel speed detected by said speed sensor, and τ

is the yaw rate detected by said yaw rate sensor.

6. An electric control system as claimed in claim 1, wherein said memory means comprises means for memorizing a plurality of connection coefficients and a plurality of threshold values to be renewed by learning based on the teacher data.

7. An electric control system as claimed in claim 1, wherein said first detection means comprises a speed sensor for detecting travel speed of the vehicle and a steering angle sensor for detecting a steering angle of a set of dirigible rear road wheels of the vehicle, and wherein said means for producing a control signal comprises first means for setting the estimated characteristic index as a variable, second means for determining a coefficient in accordance with the detected travel speed of the vehicle, third means for determining a target rear wheel steering angle on a basis of the variable and the coefficient, and fourth means for producing a control signal indicative of a difference between the target rear wheel steering angle and the detected steering angle of the rear road wheels.