Automatic traction relay valve diagnostic using pressure transducer feedback
AssigneeBendix Commercial Vehicle Systems LLC
InventorsMichael D. Tober, Timothy Carritte, Timothy J. Frashure
Life of this patent
Estimating the term…
Abstract
A system and method of diagnosing and/or mitigating the effects of a malfunctioning brake valve configured to supply pressurized fluid to a brake unit via a pressure delivery line during automated braking operations including detecting a period of no braking activity, venting the pressure delivery line to atmosphere during the period of no braking activity, monitoring pressure in the pressure delivery line to detect a pressure change resulting from the venting, and generating an error signal if a detected pressure change exceeds a threshold value. The pressure modulating valve can be periodically cycled once a fault is detected to reduce the effects thereof.
Claims23
A method of diagnosing a brake valve configured to supply pressurized fluid to a brake unit via a pressure delivery line during automated braking operations, the method comprising:
- detecting a period of no braking activity;
- venting the pressure delivery line to atmosphere during the period of no braking activity;
- monitoring pressure in the pressure delivery line to detect a pressure change resulting from the venting;
- and
- generating an error signal if a detected pressure change exceeds a threshold value.
A brake system comprising:
- at least one fluid pressure source;
- at least one brake unit;
- a pressure delivery line for delivering pressurized fluid to the at least one brake unit from the at least one fluid pressure source;
- a brake valve for controlling the flow of pressurized fluid through the pressure delivery line to the at least one brake unit during automated braking operations, the brake valve operative to supply pressurized fluid to the at least one brake unit in response to a control signal;
- a pressure sensor for sensing pressure in the pressure delivery line at a location between the brake valve and the pressure modulating valve;
- a pressure modulator valve between the brake valve and the brake unit configured to exhaust the pressurized fluid to atmosphere when actuated;
- and
- an electronic controller unit having an input for receiving data from the pressure sensor, an output for sending a control signal to the pressure modulator, a memory that stores computer-executable instructions, and a processor configured to execute the computer-executable instructions, the instructions comprising:
- actuating the pressure modulator valve to vent the pressure delivery line to atmosphere;
- calculating a pressure change resulting from the venting based on data received from the pressure sensor;
- and
- generating an error signal if a detected pressure change exceeds a threshold value.
An electronic controller unit for controlling an associated pressure modulator valve adapted to vent pressure from an associated pressure delivery line of a vehicle brake systems, the electronic controller unit comprising:
- an input for receiving data from at least one sensor configured to sense pressure in the associated pressure delivery line;
- an output for sending a control signal to the associated pressure modulator valve;
- a memory that stores computer-executable instructions;
- and
- a processor configured to execute the computer-executable instructions to generate the control signal, the instructions comprising:
- monitoring data received from the at least one sensor;
- generating a control signal to actuate the pressure modulating valve based on monitored data;
- transmitting the control signal to the pressure modulating valve via the output to vent the pressure delivery line;
- detecting a pressure change resulting from the actuation of the pressure modulating valve;
- comparing the detected pressure change to a threshold value;
- and
- generating an error signal if the detected pressure change exceeds the threshold value.
A brake system comprising:
- at least one fluid pressure source;
- at least one brake unit;
- a pressure delivery line for delivering pressurized fluid to the at least one brake unit from the at least one fluid pressure source;
- a brake valve for controlling the flow of pressurized fluid through the pressure delivery line to the at least one brake unit during automated braking operations, the brake valve operative to supply pressurized fluid to the at least one brake unit in response to a control signal;
- a pressure sensor for sensing pressure in the pressure delivery line at a location between the brake valve and the brake unit;
- and
- means for detecting a period of no braking, actuating the pressure modulator valve to vent the pressure delivery line to atmosphere, and detecting a change in pressure in the pressure delivery line resulting from the actuation of the pressure modulator valve.
A method of diagnosing a brake valve configured to supply pressurized fluid to a brake unit via a pressure delivery line during automated braking operations, the method comprising:
- venting the pressure delivery line to atmosphere after an unexpected increase in pressure is detected in the pressure delivery line;
- monitoring pressure in the pressure delivery line to detect a pressure change resulting from the venting, whereby no pressure change after venting indicates normal operation of the brake valve and the presence of electrical drift in a signal of the transducer resulting in the unexpected increase in detected pressure, and a pressure change after venting indicates a malfunctioning brake valve;
- and
- generating an error signal if a pressure change is detected.
Dependencies are inferred from the claim text.