System and method for aircraft braking system usage monitoring
The system and method for monitoring wear of one or more aircraft parts, such as an aircraft brake, an aircraft tire, a standby system, and landing gear. One or more sensors are provided for sensing a parameter of usage, and an estimate of usage of the part can be determined based upon the signal indicating the sensed value of the parameter of usage of the aircraft part. A plurality of sensors can be provided for sensing usage of a plurality of parts of the aircraft, and the estimate of usage of the part can be stored for access of the estimate by ground personnel. As applied to monitoring wear of an aircraft brake, a linear brake wear indicator attached to the brake moves a discrete distance when the brake is actuated, and a linear position encoder measures the distance traveled by the linear brake wear indicator as an indication of brake usage. A wheel speed monitor may also be provided for measuring the aircraft wheel speed, for distinguishing between static brake applications and moving brake applications, based upon the wheel speed signal.
1. A system for monitoring wear of parts of an aircraft, comprising:
at least one brake usage sensor for sensing usage of a brake of the aircraft and for generating a signal indicating a sensed value of usage of the brake, said at least one brake usage sensor including a linear brake wear indicator associated with the brake and a linear position encoder operative to measure a distance traveled by the linear brake wear indicator, and said linear position encoder being operative to generate a linear position signal indicating a distance traveled by the linear brake wear indicator as an indication of usage of the brake;
means for sensing aircraft yaw generating a yaw signal indicating aircraft yaw;
a wheel speed monitor generating a wheel speed signal indicating wheel speed of the aircraft; and
control means for determining an estimate of usage of the brake based upon said linear position signal and an estimate of usage of a tire of the aircraft based upon said wheel speed signal and said yaw signal.
2. The system of claim 1 , wherein said control means for determining an estimate of usage receives said wheel speed signal for distinguishing between static brake applications and moving brake applications based upon said wheel speed signal.
3. The system of claim 1 , wherein said wheel speed monitor comprises a wheel speed sensor.
4. The system of claim 1 , wherein said wheel speed monitor comprises an aircraft speed sensor.
5. The system of claim 1 , wherein said control means for determining an estimate of usage further comprises clock means for measuring the period of time elapsed during each brake application, means for determining a distance over which each brake application occurs, based upon the wheel speed of the aircraft during each brake application and said period of time elapsed during each brake application, and means for determining the degree to which each individual brake application contributes to brake wear based upon said distance over which each brake application occurs.
6. The system of claim 1 , wherein said wherein said linear brake wear indicator includes a plurality of longitudinally arranged markings, and said linear position encoder comprises an optical encoder for counting said markings passing by said optical encoder for determining the distance traveled by the linear brake wear indicator upon brake actuation.
7. The system claim 1 , wherein said linear brake wear indicator comprises a brake wear pin.
8. The system of claim 1 , wherein said linear brake wear indicator includes a plurality of longitudinally arranged digitized markings indicating longitudinal position on said linear brake wear indicator, and said linear position encoder comprises an optical encoder for encoding the digitized markings.
9. The system of claim 1 , further comprising means for sensing brake temperature, and for generating a temperature signal indicating brake temperature that is received by said control means for determining an estimate of usage based upon said temperature signal.
10. The system of claim 9 , wherein said control means further comprises means for estimating the degree to which each individual brake application contributes to wear based upon said temperature signal.
11. The system of claim 1 , further comprising means for sensing input power to a standby system of the aircraft and generating an input power signal;
clock means for measuring the period of time elapsed during each usage of said standby system and generating an elapsed time signal; and
wherein said control means includes means for determining an estimate of usage of said aircraft standby system based upon said input power signal and said elapsed time signal.
12. The system of claim 1 , further comprising means for sensing load on a landing gear of the aircraft and generating a load signal;
clock means for measuring the period of time elapsed during each usage of said landing gear and generating an elapsed time signal; and
wherein said control means includes means for determining an estimate of usage of said landing gear based upon said load signal and said elapsed time signal.