Control system having data correlation for controlling a vehicular anti-lock braking system

• US 5,684,702 A
• Filed: 06/16/1994
• Issued: 11/04/1997
• Est. Priority Date: 01/19/1991
• Status: Expired due to Fees

• Current Assignee: Lucas Industries Limited (Zeppelin - Stiftung der Stadt Friedrichshafen)
• Original Assignee: Lucas Industries Limited (Zeppelin - Stiftung der Stadt Friedrichshafen)
• Inventors: Bolton, John Anthony, Phillips, Mark Ian, Ainsworth, Anthony John
• Primary Examiner(s): LOUIS JACQUES, JACQUES H
• Application Number:
  US08/261,471
• Time in Patent Office: 1,237 Days
• Field of Search: 364/426.02, 364/424.05, 364/424.01, 364/431.04, 364/431.11, 364/431.12, 364/431.06, 364/431.05, 364/131, 364/133, 364/136, 364/426.015, 364/426.019, 364/426.021, 364/426.028, 364/424.045, 364/424.058, 364/426.027, 395/275, 395/375, 395/425, 395/184.01, 395/185.01, 395/183.01, 395/183.06, 395/183.07, 395/421.01, 395/497.04, 395/426, 395/439, 303/122.05, 303/22.11, 303/113.1, 303/122.01, 303/122.02, 303/122.06, 303/122.09, 303/131, 303/166, 180/141, 180/142, 180/170, 180/179, 180/287, 371/67.1, 371/68.1, 371/71, 371/21.1, 371/21.2
• US Class Current: 701/76
• CPC Class Codes: B60T 2270/416 Wheel speed sensor failure
• CPC Class Codes: B60T 8/885 using electrical circuitry
• CPC Class Codes: B60W 2050/0292 Fail-safe or redundant systems, e.g. limp-home or backup systems
• CPC Class Codes: B60W 2050/0295 Inhibiting action of specific actuators or systems
• CPC Class Codes: G05B 9/03 with multiple-channel loop, i.e. redundant control systems
• CPC Class Codes: G06F 11/0796 Safety measures, i.e. ensuring safe condition in the event of error, e.g. for controlling element
• CPC Class Codes: G06F 11/1641 where the comparison is not performed by the redundant processing components
• CPC Class Codes: G06F 11/184 where the redundant components implement processing functionality
• CPC Class Codes: G06F 11/188 where exact match is not required

Abstract

In a control system, for instance forming part of a vehicle anti-lock brake system, a plurality of control processors provides similar or identical control signals of the system in response to a shared transducer input. An independent data correlation processor compares data generated in the control processors for correlation and, in the absence of proper correlation, provides an indication which may be used to disable anti-lock operation of the brake system. In preferred embodiments, a four wheel vehicle with an anti-lock brake system is monitored by dual microprocessors. Each wheel has a speed sensor which supplies an input to each microprocessor. The data correlation processor compares the outputs of the microprocessors for each wheel and sends and alarm or disables the anti-lock brake system if the difference in the microprocessors output is beyond a limit amount.

Claims

1. A control system comprising:

a plurality of controllers, each of said controllers performing a substantially identical function and comprising a means, responsive to a common input, for providing a substantially identical control function output data; and

arbitration means for arbitrating between said controllers, said arbitration means comprising a data processor means for comparing said data from each of said controllers for correlation and for providing an output indication of lack of correlation of said data,

wherein each of said controllers comprises a control data processor and a memory for receiving parameter data from said control data processor, said data processor means receiving the parameter data from said memories and checking the parameter data for correlation and said memory of each of said controllers has a write only part for receiving the parameter data automatically from said control data processor and a read only part containing a copy of the parameter data written in said write only part for reading only by said data processor means.

2. A system for controlling the disabling of a vehicular anti-lock brake control system for a vehicle having wheels where the anti-lock system reduces braking pressure on a wheel which is determined to be locking, said disabling controlling system including:

a plurality of wheel speed sensor means for providing an output indicative of the rotational speed of a respective wheel;

a plurality of controllers, each of said controllers comprising a means, responsive to at least one wheel speed sensor means output, for providing data for substantially identical control functions;

arbitration means for arbitrating between said controllers, said arbitration means comprising a data processor means for comparing said data from said controllers for correlation and for providing an output indication of an mount of correlation of said data; and

means, responsive to said data processor means output indication of an amount of correlation of said data being less than a limit, for at least providing an alarm signal suggesting that an operator of the vehicle disable said anti-lock system, wherein said means for providing an alarm signal includes a means for disabling at least the brake pressure reduction of said anti-lock system, wherein said vehicle has four wheels, said plurality of speed sensor means comprises at least four speed sensors, at least one of said speed sensors associated with a respective one of said four wheels, said plurality of controllers comprising two microprocessors, each of said microprocessors including a separate channel responsive to each of said at least four speed sensors and the output from each sensor means is applied to each microprocessor, wherein said output data is data representative of wheel speed, and said correlation comprises comparison of the wheel speed data for one wheel applied to both microprocessors, and said limit of correlation is a function of the wheel speed, wherein said wheel speed data is reflective of wheel speeds from 0 to greater than 300 kilometers per hour, and said limit of correlation for the wheel speed range between 0 and 100 kilometers per hour is data indicative of a wheel speed difference of 1 kilometer per hour, said limit of correlation for the wheel speed range between 100 and 200 kilometers per hour is data indicative of a wheel speed difference of 2 kilometers per hour, said limit of correlation for the wheel speed range between 200 and 300 kilometers per hour is data indicative of a wheel speed difference of 3 kilometers per hour, and said limit of correlation for the wheel speed range of greater than 300 kilometers per hour is data indicative of a wheel speed difference of 4 kilometers per hour.

3. A control system comprising:

a plurality of controllers, each of said controllers having an input means responsive to common input data, and

arbitration means for arbitrating between said controllers, said arbitration means comprising a data processor for comparing data from said controllers for correlation and for providing an indication of lack of correlation, wherein each of said plurality of controllers performs a substantially identical function, wherein each of said controllers comprises a control data processor and a memory for receiving parameter data from said control data processor, said data processor receiving the parameter data from said memories and checking the parameter data for correlation and said memory of each of said controllers has a write only part for receiving the parameter data automatically from said control data processor and a read only part containing a copy of the parameter data written in said write only part for reading only by said data processor.