Servovalve analyzer system

• US 5,301,128 A
• Filed: 05/17/1993
• Issued: 04/05/1994
• Est. Priority Date: 01/16/1987
• Status: Expired due to Term

• Current Assignee: AAI Corporation (Textron Inc)
• Original Assignee: AAI/ACL Technologies, Inc.
• Inventors: Bybee, Jimmy L.
• Primary Examiner(s): Harvey, Jack B.
• Assistant Examiner(s): PIPALA, EDWARD J
• Application Number:
  US08/062,190
• Time in Patent Office: 323 Days
• Field of Search: 364/551.01, 364/550, 364/138, 364/139, 364/146, 364/176, 364/188, 364/506, 364/510, 364/571.01, 364/571.04, 364/571.07, 364/571.08, 371/15.1, 371/16.1, 371/16.4, 371/17, 371/25.1-28, 73/1 R, 73/3
• US Class Current: 702/83
• CPC Class Codes: F15B 19/00 Testing; Calibrating; Fault detection or monitoring; Simulation or modelling of fluid-pressure systems or apparatus not otherwise provided for
• CPC Class Codes: G05B 19/4063 Monitoring general control system G05B19/4062 takes precedence
• CPC Class Codes: G05B 2219/33326 Analyzer, diagnostic for servovalve

Abstract

A fully automatic servovalve analyzer system includes a data processing system, a transducer system, and a transducer interface system connecting the data processing system to the transducer system. The data processing system stores data defining characteristics of transducers connected to a unit under test as well as characteristic data for the unit under test itself and test procedures which are to be performed. After a unit under test has been hydraulically and electrically connected to the analyzer system, the system automatically performs any defined tests, analyzes the results and outputs the results in a preselected human recognizable form.

Claims

1. A system for driving an excitation means of a hydraulic unit under test with a precise signal in a predetermined sequence, comprising:

digital processor means providing a plurality of command signals for the predetermined sequence on a digital bus;

analog command signal bus means comprising a number of analog command signal lines;

digital to analog converter means coupling the digital bus to the analog command signal bus means;

sensing transducer means comprising a plurality of sensing transducers providing individual signals representative of unit under test operation of different analog input signal lines forming an analog input signal bus;

first analog signal summing means connected to the analog command signal bus and responsive to digital command signals on the digital bus for summing selected analog command signals as controlled by digital command signals;

second analog signal summing means connected to the analog input signal bus and responsive to digital command signals on the digital bus for summing selected analog input signals as controlled by digital command signals; and

means for combining the outputs of the first and second summing means as an excitation signal.

2. A system as set forth in claim 1 above, further comprising means for applying the summed selected analog input signals as a feedback signal, and means for sensing the excitation signal connected to the second analog signal summing means.

3. A system for testing a hydraulic unit under test having excitation means to derive a number of operating parameters under a sequence of test conditions using a hydraulic power source, comprising:

a digital processor comprising a digital data bus for transferring digital commands and digital outputs, the digital commands defining a test sequence;

analog command signal bus means comprising a plurality of analog command signal lines;

digital to analog converter means responsive to the digital commands on the digital data bus and providing commands on selected analog command signal lines;

servoamplifier means coupled to the digital data bus and the selected analog command signal lines for operating the excitation means in a controlled sequence;

a plurality of different transducer means coupled to the unit under test for sensing different parameters of operation;

analog input signal bus means comprising a plurality of input signal lines, each coupled to receive different transducer signals; and

analog to digital converter means coupling the analog input signal bus to the digital bus for the digital processor.

4. A system as set forth in claim 3 above, wherein the unit under test has a plurality of hydraulic ports and the system further comprises a plurality of signal actuated valves each coupled to a different port of the unit under test, and valve interface means coupled to the digital data bus and providing signals to control the different valves in response to digital commands.

5. A system as set forth in claim 3 above, further comprising signal generator means coupled to the analog command signal bus and responsive to commands on the digital data bus for providing repetitive signals of selected waveforms and periodicity.

6. A system as set forth in claim 5 above, wherein the signal generator means further comprises multiplexer means for providing selected repetitive signals on selected lines of the analog command signal bus.

7. A system as set forth in claim 3 above, wherein the system further comprises a plurality of signal conditioning circuits, each coupling a different transducer means to the analog input signal bus and each providing compensation for at least one characteristic of the associated transducer means.

8. A system as set forth in claim 5 above, wherein the analog command signal bus means comprises a plurality of pairs of differential analog signal lines, and wherein the analog input signal bus means comprises a plurality of lines including at least one for each signal conditioning circuit.

9. A system as set forth in claim 3, wherein the servoamplifier means comprises at least two programmable servoamplifiers, each providing servo output signals within a selected range.

10. A system as set forth in claim 3 above, wherein the digital to analog converter means further comprises multiplexer means for coupling signals to selected lines of the analog command signal bus means, and the analog to digital converter means further comprises multiplexer means for receiving signals on selected lines of the analog input signal bus means.