Acceptance testing of actuators using predetermined thresholds

• US 7,283,934 B2
• Filed: 07/27/2005
• Issued: 10/16/2007
• Est. Priority Date: 07/28/2004
• Status: Expired due to Fees

• Current Assignee: HR Textron, Inc.
• Original Assignee: HR Textron, Inc.
• Inventors: Deller, Robert W., Lee, Joon H.
• Primary Examiner(s): Bui; Bryan
• Assistant Examiner(s): TEIXEIRA MOFFAT, JONATHAN CHARLES
• Application Number:
  US11/190,303
• Publication Number:
  US 20060036402A1
• Time in Patent Office: 811 Days
• Field of Search: None
• US Class Current: 702/183
• CPC Class Codes: B64F 5/60 Testing or inspecting aircraft components or systems
• CPC Class Codes: F15B 19/005 Fault detection or monitoring
• CPC Class Codes: G01R 31/2829 Testing of circuits in sensor or actuator systems testing of apparatus for measuring electric or magnetic variables G01R35/00; testing of indicating or recording apparatus G01D; in airbag systems B60R21/0173; checking gas analysers G01N33/007; monitoring or fail-safe circuits for electromagnets H01F7/1844
• CPC Class Codes: G01R 31/343 in operation
• CPC Class Codes: G05B 19/4063 Monitoring general control system G05B19/4062 takes precedence
• CPC Class Codes: G05B 2219/42298 Measure backlash, time difference between point A to point B and from B to A, if too large
• CPC Class Codes: G05B 2219/45071 Aircraft, airplane, ship cleaning manipulator, paint stripping
• CPC Class Codes: G05B 23/0254 based on a quantitative model, e.g. mathematical relationships between inputs and outputs; functions: observer, Kalman filter, residual calculation, Neural Networks

Abstract

An improved technique of acceptance testing an actuator system involves measuring system parameters of the actuator system during operation of the actuator system, and storing the measured system parameters in computerized memory as a set of measured system parameters. The technique further involves obtaining a set of predetermined thresholds. Each predetermined threshold corresponds to a particular measured system parameter. The technique further involves electronically indicating whether the actuator system is in acceptable condition based on an electronic comparison of the set of measured system parameters stored in the computerized memory and the set of predetermined thresholds, e.g., providing a warning of a need for service or of imminent failure when one or more of the system parameters exceeds a corresponding threshold.

Claims

1. A test system to acceptance test a first actuator system, the test system comprising:

a data acquisition circuit configured to interface with the first actuator system;

a controller including a processing core and computerized memory; and

a communications medium which connects the data acquisition circuit to the controller,

wherein the processing core is configured to;

maintain a database of experience formed from system parameter values of a second actuator system of the same type as the first actuator system, the system parameter values of the second actuator system being obtained during operation of the second actuator system at a time of failure of the second actuator system;

set thresholds for system parameter values of the first actuator system based on the system parameter values of the second actuator system at the time of failure of the second actuator system;

measure system parameter values of the first actuator system during operation of the first actuator system and storing the measured system parameter values in computerized memory as a set of measured system parameter values;

and electronically indicate whether the first actuator system is in acceptable condition based on an electronic comparison between the thresholds and the measured system parameter values stored in the computerized memory.

2. A test system as in claim 1 wherein the processing core, when measuring the system parameters values of the first actuator system during operation of the first actuator system, is configured to:

direct the data acquisition circuit to receive sensor signals from sensors of the first actuator system, the sensor signals identifying operating conditions of the first actuator system during operation; and

direct the data acquisition circuit to quantify the operating conditions identified by the sensor signals as at least a portion of the system parameters values of the first actuator system.

3. A test system as in claim 2 wherein the data acquisition circuit includes a set of counters;

and wherein the processing core, when directing the data acquisition circuit to quantify the operating conditions identified by the sensor signals, is configured to;

enable incrementing of the set of counters based on particular operating events identified by the sensor signals to count the particular operating events.

4. A test system as in claim 2 wherein the data acquisition circuit includes a set of integrators;

and wherein the processing core, when directing the data acquisition circuit to quantify the operating conditions identified by the sensor signals, is configured to;

enable collecting, within the set of integrators, cumulative sums of particular operating conditions defined by the sensor signals multiplied by times of exposure to the particular operating conditions to record total cumulative exposure times to the particular operating conditions.

5. A test system as in claim 2 wherein the data acquisition circuit includes a set of peak detectors;

and wherein the processing core, when directing the data acquisition circuit to quantify the operating conditions identified by the sensor signals, is configured to;

enable tracking, within the set of peak detectors, particular operating conditions identified by the sensor signals to determine greatest magnitudes of the particular operating conditions.

6. A test system as in claim 1 wherein the system parameters values of the second actuator system were obtained during operation of the second actuator system within an aircraft working environment and have system parameter types;

and wherein the processing core, when setting the thresholds, is configured to;

calculate an average, a maximum, and a minimum value for each system parameter type, and

set the thresholds from the average, maximum and minimum values for each system parameter type.

7. A test system as in claim 1 wherein the processing core, when setting the thresholds, is configured to:

statistically analyze the database of experience to correlate the database of experience with external test and failure data as represented by the system parameter values of the second actuator system at the time of failure of the second actuator system; and

set the threshold values based on the statistical analysis.

8. A test system as in claim 1 wherein the processing core is further configured to compute profiles of the system parameters values over at least one type of range selected from the group consisting of position, time and temperature.

9. A test system as in claim 8 wherein the processing core, when computing profiles of the system parameters values, is configured to compute profiles of the system parameters values over a range of actuator motion.

10. A test system as in claim 8 wherein the profiles are selected from the group consisting of Total Flight Time, Controller Temperature Profile, Motor Temperature Profile, Average Actuator Position, Position/Time Profile, Distance by Position Profile, Load by Position Profile, Work by Position Profile, Peak Load by Position Profile, Peak Work by Position Profile, Peak Hall State/Potentiometer by Position, Illegal Hall States, and Watchdog Events.

11. A method of acceptance testing a first actuator system, comprising:

maintaining a database of experience formed from system parameter values of a second actuator system of the same type as the first actuator system, the system parameter values of the second actuator system being obtained during operation of the second actuator system at a time of failure of the second actuator system;

setting thresholds for system parameter values of the first actuator system based on the system parameter values of the second actuator system at the time of failure of the second actuator system;

measuring system parameter values of the first actuator system during operation of the first actuator system and storing the measured system parameter values in computerized memory as a set of measured system parameter values;

and electronically indicating whether the first actuator system is in acceptable condition based on an electronic comparison between the thresholds and the measured system parameter values stored in the computerized memory.

12. A method as in claim 11 wherein measuring the system parameters values of the first actuator system during operation of the first actuator system includes:

receiving sensor signals within a data acquisition circuit from sensors of the first actuator system, the sensor signals identifying operating conditions of the first actuator system during operation; and

quantifying, within the data acquisition circuit, the operating conditions identified by the sensor signals as at least a portion of the system parameters values of the first actuator system.

13. A method as in claim 12 wherein the data acquisition circuit includes a set of counters;

and wherein quantifying the operating conditions identified by the sensor signals includes;

incrementing the set of counters based on particular operating events identified by the sensor signals to count the particular operating events.

14. A method as in claim 12 wherein the data acquisition circuit includes a set of integrators;

and wherein quantifying the operating conditions identified by the sensor signals includes;

collecting, within the set of integrators, cumulative sums of particular operating conditions defined by the sensor signals multiplied by times of exposure to the particular operating conditions to record total cumulative exposure times to the particular operating conditions.

15. A method as in claim 12 wherein the data acquisition circuit includes a set of peak detectors;

and wherein quantifying the operating conditions identified by the sensor signals includes;

tracking, within the set of peak detectors, particular operating conditions identified by the sensor signals to determine greatest magnitudes of the particular operating conditions.

16. A method as in claim 11 wherein the system parameters values of the second actuator system were obtained during operation of the second actuator system within an aircraft working environment and have system parameter types;

and wherein setting the thresholds includes;

calculating an average, a maximum, and a minimum value for each system parameter type, and

setting the thresholds from the average, maximum and minimum values for each system parameter type.

17. A method as in claim 11 wherein defining the set of threshold values includes:

statistically analyzing the database of experience to correlate the database of experience with external test and failure data as represented by the system parameter values of the second actuator system at the time of failure of the second actuator system; and

setting the threshold values based on the statistical analysis.

18. A method as in claim 11 further including:

computing profiles of the system parameters values over at least one type of range selected from the group consisting of position, time and temperature.

19. A method as in claim 18 wherein computing profiles of the system parameters values comprises computing profiles of the system parameters values over a range of actuator motion.

20. A method as in claim 18 wherein the profiles are selected from the group consisting of Total Flight Time, Controller Temperature Profile, Motor Temperature Profile, Average Actuator Position, Position/Time Profile, Distance by Position Profile, Load by Position Profile, Work by Position Profile, Peak Load by Position Profile, Peak Work by Position Profile, Peak Hall State/Potentiometer by Position, Illegal Hall States, and Watchdog Events.