Brake system for vehicles

• US 6,412,885 B1
• Filed: 01/10/2000
• Issued: 07/02/2002
• Est. Priority Date: 07/10/1997
• Status: Expired due to Fees

• Current Assignee: Toyota Jidosha Kabushiki Kaisha (Toyota Motor Corporation)
• Original Assignee: Toyota Jidosha Kabushiki Kaisha (Toyota Motor Corporation)
• Inventors: Yoshino, Yasunori, Otomo, Akihiro, Shirai, Kenji, Inoue, Hideyuki
• Primary Examiner(s): Rodriguez, Pam
• Assistant Examiner(s): KRAMER, DEVON C
• Application Number:
  US09/462,684
• Time in Patent Office: 904 Days
• Field of Search: 303/122.03, 303/122.05, 303/122.09, 303/122.1, 303/140, 303/141, 303/142, 303/146, 303/189
• US Class Current: 303/122.09
• CPC Class Codes: B60T 13/74 with electrical assistance or drive
• CPC Class Codes: B60T 8/00 Arrangements for adjusting wheel-braking force to meet varying vehicular or ground-surface conditions, e.g. limiting or varying distribution of braking force by changing number of effective brake cylinders in power brake systems B60T17/10
• CPC Class Codes: B60T 8/1755 Brake regulation specially adapted to control the stability of the vehicle, e.g. taking into account yaw rate or transverse acceleration in a curve road vehicle drive control systems for control of driving stability otherwise than by controlling a particular sub-unit B60W30/02
• CPC Class Codes: B60T 8/246 Change of direction
• CPC Class Codes: B60T 8/92 automatically taking corrective action

Abstract

In order to prevent a needlessly excessive yaw moment from being applied to the vehicle, thereby improving the running stability of the vehicle when either one of the braking force generation units went wrong, a brake system for vehicles having electric brake units (14) each provided for each of the wheels to generate a braking force by its actuator (22) being driven according to the amount of depression of a brake pedal, and a controller (38) for controlling each of the electric brake units independently of others, is so constructed as to judge if any of the electric brake units went wrong (step 253, 259, 550, 650), and when either one of the electric brake units went wrong, to control the electric brake units other than the wrong unit according to the depression amount of the brake pedal so as to accomplish a best available stability of running of the vehicle.

Claims

1. A brake system for vehicles, comprising braking force generation means each provided for each of wheels to generate a braking force individually in each wheel according to an amount of depression of a brake pedal, and control means for controlling each of the braking force generation means for each of the wheels independently of the other braking force generation means for the other wheels, wherein when any one of the braking force generation means malfunctions not to substantially release a generated braking force, the control means operates one of the braking force generation means positioned transversely opposite to the malfunctioning braking force generation means according to the magnitude of the unreleased braking force so as to generate a braking force that prevents a needless yaw moment from being applied to the vehicle.

2. A brake system for vehicles, comprising braking force generation means each provided for each of wheels to generate a braking force individually in each wheel according to an amount of depression of a brake pedal, and control means for controlling each of the braking force generation means for each of the wheels independently of the other braking force generation means for the other wheels, wherein the control means comprises means for calculating a target yaw moment for the vehicle according to a running condition of the vehicle, and when any one of the braking force generation means malfunctions, the control means operates other three normal braking force generationmeans, so that the yaw moment of the vehicle substantially coincides with the target yaw moment.

3. A brake system for vehicles, comprising braking force generation means each provided for each of wheels to generate a braking force individually in each wheel according to an amount of depression of a brake pedal, and control means for controlling each of the braking force generation means for each of the wheels independently of the other braking force generation means for the other wheels, wherein when any one of the braking force generation means malfunctions to generate substantially no braking force, the control means operates other normal ones of the braking force generation means including a braking force generation means transversely opposite to the malfunctioning braking force generation means, so that the braking force generated by one of the braking force generation means positioned longitudinally opposite to the malfunctioning braking force generation means substantially coincides with the sum of the braking forces generated by front and rear ones of the braking force generation means positioned on a side transversely opposite to the malfunctioning braking force generation means.

4. A brake system for vehicles, comprising braking force generation means each provided for each of wheels to generate a braking force individually in each wheel according to an amount of depression of a brake pedal, and control means for controlling each of the braking force generation means for each of the wheels independently of the other braking force generation means for the other wheels, wherein the vehicle has an engine for generating a kinetic energy for the vehicle to run, and when any one of the braking force generation means malfunctions not to substantially release a generated braking force, the control means operates one of the braking force generation means positioned transversely opposite to the malfunctioning braking force generation means to generate a braking force the prevents a needless yaw moment from being applied to the vehicle, while the control means restricts the generation of the kinetic energy by the engine.

5. A brake system for vehicles according to claim 4, wherein the braking force generation means includes an electric motor as an actuator.

6. A brake system for vehicles, comprising braking force generation means each provided for each of wheels to generate a braking force individually in each wheel according to an amount of depression of a brake pedal, and control means for controlling each of the braking force generation means for each of the wheels independently of the other braking force generation means for the other wheels, wherein when any one of the braking force generation means malfunctions, the control means modifies the braking forces generated by normal ones of the braking force generation means so that the modified braking forces cancel the yaw moment which would otherwise be applied to the vehicle by the malfunctioning braking force generation means and the normal braking force generation means according to the depression of the brake pedal.

7. A brake system for vehicles according to claim 6, wherein the vehicle has an engine for generating a kinetic energy for the vehicle to run, and when any one of the braking force generation means malfunctions, the control means decreases the generation of the kinetic energy by the engine.

8. A brake system for vehicles, comprising braking force generation means each provided for each of wheels to generate a braking force individually in each wheel according to an amount of depression of a brake pedal, and control means for controlling each of the braking force generation means for each of the wheels independently of the other braking force generation means for the other wheels, wherein when any one of the braking force generation means malfunctions, the control means controls the normal braking force generation means so as to prevent a needless yaw moment from being applied to the vehicle, and wherein it is judged if there is any allowance for increase in the braking force available by one of the braking force generation means positioned longitudinally opposite to the malfunctioning braking force generation means, and when there is no allowance in the available braking force, the target braking force for one of the braking force generation means positioned longitudinally opposite to the malfunctioning braking force generation means is set to the available braking force, so that the target braking forces for other wheels are set according to the available braking force.

9. A brake system for vehicles, comprising braking force generation means each provided for each of wheels to generate a braking force individually in each wheel according to an amount of depression of a brake pedal, and control means for controlling each of the braking force generation means for each of the wheels independently of the other braking force generation means for the other wheels, wherein when any one of the braking force generation means malfunctions, the control means controls the normal braking force generation means so as to prevent a needless yaw moment from being applied to the vehicle, and wherein when any one of the braking force generation means malfunctions not to substantially release a generated braking force, when the vehicle is running straight forward, the target braking force of one of the braking force generation means positioned transversely opposite to the malfunctioning braking force generation means is set to be substantially equal to the braking force generated by the malfunctioning braking force generation means, while when the vehicle is substantially turning, the target braking force of one of the braking force generation means positioned diagonally opposite to the malfunctioning braking force generation means is set to be substantially equal to the braking force generated by the malfunctioning braking force generation means.

10. A brake system for vehicles, comprising brake force generation means each provided for each of wheels to generate a braking force individually in each wheel according to an amount of depression of a brake pedal, and control means for controlling each of the braking force generation means for each of the wheels independently of the other braking force generation means for the other wheels, wherein when any one of the braking force generation means malfunctions, the control means controls the normal braking force generation means so as to prevent a needless yaw moment from being applied to the vehicle, and wherein the control means is constructed to calculate the target braking force of one of the braking force generation means positioned longitudinally opposite to the malfunctioning braking force generation means according to an amount of depression of the braking pedal, and to calculate the target braking forces of front and rear ones of the braking force generation means on a side transversely opposite to the side of the malfunctioning braking force generation means so that the sum thereof is substantially equal to the target braking force of the above-mentioned one braking force generation means, so as thereby to control the braking forces of all of the braking force generation means, except the malfunctioning braking force generation means, to correspond to the target braking forces respectively corresponding thereto.