Automatic brake control system and the method thereof

• US 5,904,215 A
• Filed: 08/15/1996
• Issued: 05/18/1999
• Est. Priority Date: 09/14/1995
• Status: Expired due to Fees

• Current Assignee: Fuji Jukogyo KK (Subaru Corp.)
• Original Assignee: Fuji Jukogyo KK (Subaru Corp.)
• Inventors: Ikeda, Atsushi
• Primary Examiner(s): Oberleitner, Robert J.
• Assistant Examiner(s): Lipka, Pamela J.
• Application Number:
  US08/700,731
• Time in Patent Office: 1,006 Days
• Field of Search: 180/167, 180/168, 180/169, 180/170, 180/176, 180/177, 180/178, 180/179, 303/113.4, 303/155, 303/193, 701/93, 701/301
• US Class Current: 180/169
• CPC Class Codes: B60K 31/0008 including means for detecting potential obstacles in vehicle path
• CPC Class Codes: B60T 2220/02 Driver type; Driving style; Driver adaptive features
• CPC Class Codes: B60T 7/22 initiated by contact of vehicle, e.g. bumper, with an external object, e.g. another vehicle , or by means of contactless obstacle detectors mounted on the vehicle
• CPC Class Codes: B60T 8/174 characterised by using special control logic, e.g. fuzzy logic , neural computing
• CPC Class Codes: B60W 2540/12 Brake pedal position

Abstract

An automatic brake control system brakes a driving vehicle according to a target brake control amount calculated by a neural network. The system detects vehicle speed of the driving vehicle, and detects the actual distance between the driving vehicle and a vehicle ahead of the driving vehicle. The system calculates a reference distance defined as a physically preferred distance between the driving vehicle and the vehicle ahead of the driving vehicle according to the vehicle speed, and normalizes the actual distance with the reference distance in order to obtain a normalized distance in a dimensionless quantity. The neural network calculates target brake control amount according to the vehicle speed and the normalized distance, and the automatic brake control system brakes the driving vehicle according to the target brake control amount.

Claims

1. An automatic brake control system of a vehicle having an engine, a foot brake pedal and an ignition switch, the system including a vehicle speed sensor for detecting a vehicle speed, a vehicle-to-vehicle distance detecting device for detecting an actual distance between said vehicle and another vehicle running ahead of said vehicle, a brake sensor for sensing a depression amount of said foot brake pedal and an automatic brake apparatus for automatically applying brakes to said vehicle, comprising:

reference vehicle-to-vehicle distance calculating means for calculating a reference distance between said vehicle and said other vehicle according to a formula parameterizing at least said vehicle speed;

normalized vehicle-to-vehicle distance calculating means for calculating a normalized distance between said vehicle and said other vehicle according to a normalization formula parameterizing a ratio of said actual distance and said reference distance; and

target brake control amount calculating means including at least one neural network for calculating a target brake control amount based on at least said vehicle speed and said normalized vehicle-to-vehicle distance and outputting said target brake control amount to said automatic brake apparatus.

2. The automatic brake control system according to claim 1, wherein

an auto/manual switch is provided for stopping outputting said target brake control amount to said automatic brake apparatus.

3. An automatic brake control system of a vehicle having an engine, a foot brake pedal and an ignition switch, the system including a vehicle speed sensor for detecting a vehicle speed, a vehicle-to-vehicle distance detecting device for detecting an actual distance between said vehicle and another vehicle running ahead of said vehicle, a brake sensor for sensing a depression amount of said foot brake and an automatic brake apparatus for automatically applying brakes to said vehicle, comprising:

reference vehicle-to-vehicle distance calculating means for calculating a reference distance between said vehicle and said other vehicle according to a formula parameterizing at least said vehicle speed;

normalized vehicle-to-vehicle distance calculating means for calculating a normalized distance between said vehicle and said other vehicle according to a normalization formula parameterizing a ratio of said actual distance and said reference distance;

first memory means for memorizing a driver'"'"'s data including at least said vehicle speed, said normalized distance between said vehicle and said other vehicle and said depression amount at least while said foot brake pedal is depressed by a driver during a normal operation of said vehicle;

second memory means for memorizing a standard data including at least said vehicle speed, said normalized distance between said vehicle and said other vehicle and said depression amount;

output controlling means for outputting said driver'"'"'s data and said standard data when said driver finishes depressing said brake pedal;

selecting signal generating means for generating a selection signal when said ignition switch is turned on;

neural network selecting means responsive to said selection signal for selecting at least one neural network for control use and for selecting at least one rest neural network for learning use;

controlling and learning means with respect to said neural network selected for learning use for learning said driver'"'"'s data and said standard data based on said vehicle speed and said normalized distance between said vehicle and said other vehicle and for producing a learned data, and concurrently with respect to said neural network selected for control use for calculating and selectively outputting a target brake control amount based on said vehicle speed and said normalized distance between said vehicle and said other vehicle with reference to said learned data; and

output switching means responsive to said selection signal for selecting said target brake control amount calculated in said neural network selected for control use and for outputting said target brake control amount to said automatic brake apparatus.

4. The automatic brake control system according to claim 3, wherein

an auto/manual switch is provided for stopping outputting said target brake control amount to said automatic brake apparatus.

5. The automatic brake control system according to claim 3, wherein

said selecting signal generating means comprise a counter value generating circuit from which a counter value corresponding to each of said neural networks is generated each time said ignition switch is turned on.

6. An automatic brake control method of a vehicle having an engine, a foot brake pedal and an ignition switch, the system including a vehicle speed sensor for detecting a vehicle speed, a vehicle-to-vehicle distance detecting device for detecting an actual distance between said vehicle and another vehicle running ahead of said vehicle, a brake sensor for sensing a depression amount of said foot brake pedal and an automatic brake apparatus for automatically applying brakes to said vehicle, comprising the steps of:

calculating a reference distance between said vehicle and said other vehicle according to a formula parameterizing at least said vehicle speed;

calculating a normalized distance between said vehicle and said other vehicle according to a normalization formula parameterizing a ratio of said actual distance and said reference distance; and

calculating and outputting a target brake control amount based on at least said vehicle speed and said actual distance between said vehicle and said other vehicle.

7. An automatic brake control method of a vehicle having an engine, a foot brake pedal and an ignition switch, the system including a vehicle speed sensor for detecting a vehicle speed, a vehicle-to-vehicle distance detecting device for detecting an actual distance between said vehicle and another vehicle running ahead of said vehicle, a brake sensor for sensing a depression amount of said foot brake and an automatic brake apparatus for automatically applying brakes to said vehicle, comprising the steps of:

calculating a reference distance between said vehicle and said other vehicle according to a formula parameterizing at least said vehicle speed;

calculating a normalized distance between said vehicle and said other vehicle according to a normalization formula parameterizing a ratio of said actual distance and said reference distance;

memorizing a driver'"'"'s data including at least said vehicle speed, said normalized distance between said vehicle and said other vehicle and said depression amount at least while said foot brake pedal is depressed by a driver during a normal operation of said vehicle;

memorizing a standard data including at least said vehicle speed, said normalized distance between said vehicle and said other vehicle and said depression amount;

outputting said driver'"'"'s data and said standard data when said driver finishes pressing said brake pedal;

generating a selection signal when said ignition switch is turned on;

responsive to said selection signal selecting at least one neural network as a control use and selecting at least one rest neural network as a learning use;

with respect to said neural network selected for learning use, learning said driver'"'"'s data and said standard data based on said vehicle speed and said normalized distance between said vehicle and said other vehicle and producing a learned data, and with respect to said neural network selected for control use, calculating and selectively outputting a target brake control amount based on said vehicle speed and said normalized distance between said vehicle and said other vehicle with reference to said learned data; and

selecting said target brake control amount calculated by said neural network selected for control use and outputting said target brake control amount to said automatic brake apparatus.

8. An automatic brake control system for automatically braking a driving vehicle according to a distance between said driving vehicle and a vehicle ahead of said driving vehicle, comprising:

vehicle speed detecting means for detecting a vehicle speed of said driving vehicle;

actual distance detecting means for detecting an actual distance between said driving vehicle and said vehicle ahead of said driving vehicle;

reference distance calculating means for calculating a reference distance defined as a physically preferable distance between said driving vehicle and said vehicle ahead of said driving vehicle according to at least said vehicle speed;

normalized distance calculating means for normalizing said actual distance with said reference distance to obtain a normalized distance in a dimensionless quantity;

target brake control amount calculating means including at least one neural network for calculating a target brake control amount according to said vehicle speed and said normalized distance; and

automatic braking means for automatically braking said driving vehicle according to said target brake control amount.

9. An automatic brake control system for automatically braking a driving vehicle according to a distance between said driving vehicle and a vehicle ahead of said driving vehicle, comprising:

vehicle speed detecting means for detecting a vehicle speed of said driving vehicle;

actual distance detecting means for detecting an actual distance between said driving vehicle and said vehicle ahead of said driving vehicle;

reference distance calculating means for calculating a reference distance defined as a physically preferable distance between said driving vehicle and said vehicle ahead of said driving vehicle according to at least said vehicle speed;

normalized distance calculating means for normalizing said actual distance with said reference distance to obtain a normalized distance in a dimensionless quantity;

target brake control amount calculating means including a plurality of neural networks being alternatively switched between control use and learning use wherein one of said neural networks is in control use to calculate a target brake control amount according to said vehicle speed and said normalized distance while other of said plurality of neural networks is in learning use for learning a tendency of driving; and

automatic braking means for automatically braking said driving vehicle according to said target brake control amount.

10. The automatic brake control system according to claim 9, wherein said plurality of neural networks are alternatively switched in accordance with a number of turning-on of an ignition switch.

11. The automatic brake control system according to claim 9, further comprising a memory for memorizing driving data of the vehicle speed and the normalized distance at a braking operation by a driver in order to provide said driving data for the learning use.

12. The automatic brake control system according to claim 9, further comprising:

a first memory for memorizing driving data of said vehicle speed and said normalized distance at a braking operation by a driver in order to provide said driving data for said learning use; and

a second memory for memorizing standard data of said vehicle speed and said normalized distance in order to relieve a property of said neural network when said property of said neural network is accidentally changed.

13. The automatic brake control system according to claim 9, further comprising a switch used to stop the operation of said automatic braking means in order to advance said learning in said neural network for said learning use.