CONTROLLED WHEEL BRAKING SYSTEM

• US 3,724,916 A
• Filed: 06/21/1971
• Issued: 04/03/1973
• Est. Priority Date: 06/21/1971
• Status: Expired due to Term

• Current Assignee: Edgar A. Hirzel
• Original Assignee: Edgar A. Hirzel
• Inventors: Hirzel, Edgar A.
• Primary Examiner(s): Buchler, Milton
• Assistant Examiner(s): Kunin, Stephen G.
• Application Number:
  US05/154,990
• Time in Patent Office: 652 Days
• Field of Search: 188/181 303/20,21 324/160-162 340/262-263
• US Class Current: 303/126
• CPC Class Codes: B60T 8/1703 for aircrafts

Abstract

A brake control is provided with a system for modifying the action of the brake application device for the wheel of a vehicle. Information obtained from the rotation of the wheel is used to derive an analog signal indicating the braking condition. If the analog signal exceeds a first threshold level, a first brake control signal is produced including the time integral function of the analog signal. If the analog signal exceeds a second threshold level, which is greater than the first threshold level, a second brake control signal is produced. The second brake control signal is substantially a linear function of the analog signal. The first and second brake control signals are continuously summed to produce a composite brake control signal for modifying the level of brake pressure exerted by the brake application device. The system also may include a lag compensating for summation with the first and second brake control signals in forming the composite brake control signal.

Claims

1. In a system for modifying the action of the brake application means for the wheel of a vehicle having means utilizing information obtained from the rotation of said wheel for deriving an analog signal indicating a braking condition, the improvement comprising:

means responsive to said analog signal to produce a first brake control signal when said analog signal exceeds a first threshold level, said first brake control signal including a time integral function of said analog signal;

means respOnsive to said analog signal for producing a second brake control signal when said analog signal exceeds a second threshold level; and

control means responsive to said first and second brake control signals for modifying the action of said brake application means.

2. The invention defined in claim 1 wherein said first and second brake control signals are continuously summed by said control means to produce a composite brake control signal for modifying the level of brake pressure exerted by said brake application means.

3. The invention defined in claim 2 further comprising means for providing a system lag compensating signal for summation with said first and second brake control signals in forming said composite brake control signal.

4. The invention defined in claim 1 wherein said second bake control signal is substantially a linear function of said analog signal.

5. The invention defined in claim 1 wherein said second threshold level is greater than said first threshold level.

6. The invention defined in claim 1 wherein said first brake control signal is a time integral function of both positive and negative variation of said analog signal from said first threshold level.

7. In a system for modifying the action of the brake application means for the wheel of a vehicle including means responsive to rotation of said wheel for producing an error signal, the improvement comprising:

means responsive to said error signal to produce a first brake control signal when said error signal exceeds a first threshold level, said first brake control signal being a time integral function of the variation of said error signal from said first threshold level;

means responsive to said error signal for producing a second brake control signal when said error signal exceeds a second threshold level, said second brake control signal being a substantially linear function of said error signal; and

control means responsive to said first and second brake control signals for modifying the action of said brake application means.

8. The invention defined in claim 7 wherein said first and second brake control signals are continuously summed by said control means to produce a composite brake control signal for modifying the level of brake pressure exerted by said brake application means.

9. The invention defined in claim 8 further comprising means for providing a system lag compensating signal for summation with said first and second brake control signals in forming said composite brake control signal.

10. The invention defined in claim 7 wherein said second threshold level is greater than said first threshold level.

11. The invention defined in claim 7 wherein said first brake control signal is a time integral function of both positive and negative variation of said error signal from said first threshold level.

12. In a system for modifying the action of the brake application means for the wheel of a vehicle having means responsive to rotation of said wheel for producing a slip error signal, the improvement comprising:

means responsive to said slip error signal to produce a modulating brake control signal when said slip error signal exceeds a first threshold level, said modulating brake control signal being a time integral function of the variation of said slip error signal from said first threshold level;

means responsive to said slip error signal for producing a transient brake control signal when said slip error signal exceeds a second threshold level, said second threshold level being greater than said first threshold level and said transient brake control signal being a substantially linear function of said slip error signal; and

means responsive to said modulating and transient brake control signals for continuously summing said modulating and transient brake control signals to produce a composite brake control for modifying the action of said brake application means.

13. The invention defined in claim 12 further comprisIng means for providing a system lag compensating signal for summation with said modulating and transient brake control signals in forming said composite brake control signal.

14. The invention defined in claim 13 wherein said modulating brake control signal is a time integral function of both positive and negative variation of said slip error signal from said first threshold level.

15. In a system for modifying the action of the brake application means for the wheel of a vehicle having means utilizing information obtained from the rotation of said wheel for deriving an analog signal indicating a braking condition, the improvement comprising:

means responsive to said analog signal to produce a modulating brake control signal when said analog signal exceeds a modulation threshold level, said modulating brake control signal being a gradually changing function of said analog signal;

means responsive to said analog signal for producing a transient brake control signal when said analog signal exceeds a transient brake relaxation threshold level; and

control means responsive to said modulating and transient brake control signals for modifying the action of said brake application means.

16. The invention defined in claim 15 wherein said transient brake relaxation threshold level is greater than said modulation threshold level.

17. In a system for modifying the action of the brake application means for the wheel of a vehicle having means utilizing information obtained from the rotation of said wheel for deriving at least one analog signal indicating a braking condition, the improvement comprising:

means responsive to at least one analog signal to produce a first brake control signal when said analog signal exceeds a first threshold level, said first brake control signal being a time integral function of said analog signal;

means responsive to at least one analog signal for producing a second brake control signal when said analog signal exceeds a second threshold level; and

control means responsive to said first and second brake control signals for modifying the action of said brake application means.