Health monitoring for proportional actuators

A computer-implemented method for determining a scheduled maintenance session for a proportional actuator, the method comprising:

• transmitting a command signal to a controller of the proportional actuator;
• generating, using the controller, a drive signal for controlling the proportional actuator using the command signal;
• changing, on the basis of the drive signal, a position of a component actuator of the proportional actuator;
• measuring, using a sensor, the position of the component actuator and generating a position feedback signal on the basis of the measurement;
• estimating, with a processor, a condition indicator using at least two of:
• the command signal, the drive signal or the position feedback signal, the condition indicator being indicative of a progressive degradation of the proportional actuator, wherein the condition indicator is estimated based on an amplitude of detected oscillations in the at least two of the command signal, the drive signal or the position feedback signal;
• estimating, with the processor, a health indicator using the condition indicator, the health indicator being indicative of a probability of failure of the proportional actuator at one or more future times;
• and
• determining, with the processor, a scheduled maintenance session of the proportional actuator using the estimated health indicator.

A hydromechanical unit, comprising:

• a proportional actuator comprising a controller and a component actuator, the controller operable to generate a drive signal for altering a position of the component actuator on the basis of a command signal received at the controller;
• a sensor configured to measure a position of the component actuator and to generate a position feedback signal based on the measured position;
• and
• a processor configured to estimate a condition indicator using only one of:
• the command signal, the drive signal or the position feedback signal, the condition indicator being indicative of a progressive degradation of the proportional actuator, wherein the condition indicator is estimated based on an amplitude of detected oscillations in the one of the command signal, the drive signal or the position feedback signal;
• and estimate a health indicator using the estimated condition indicator, the health indicator being indicative of a probability of failure of the proportional actuator at one or more future times;
• and determine a scheduled maintenance session of the proportional actuator using the health indicator.