Method to extend testing through integration of measured responses virtual models

• US 7,383,738 B2
• Filed: 12/03/2004
• Issued: 06/10/2008
• Est. Priority Date: 12/05/2003
• Status: Active Grant

• Current Assignee: MTS Systems Corporation (Illinois Tool Works Inc.)
• Original Assignee: MTS Systems Corporation (Illinois Tool Works Inc.)
• Inventors: Schulz, Bradley D.
• Primary Examiner(s): NOORI, MAX H
• Application Number:
  US11/004,308
• Publication Number:
  US 20050120802A1
• Time in Patent Office: 1,285 Days
• Field of Search: 737/81, 623/912
• US Class Current: 73/781
• CPC Class Codes: A61F 2/38 for elbows or knees
• CPC Class Codes: A61F 2/468 Testing instruments for artificial joints for testing non-implantable prostheses A61F2/76
• CPC Class Codes: A61F 2002/4632 using computer-controlled surgery, e.g. robotic surgery
• CPC Class Codes: G01N 2203/0089 Biorheological properties
• CPC Class Codes: G01N 2203/0246 Special simulation of "in situ" conditions, scale models or dummies
• CPC Class Codes: G01N 3/02 Details
• CPC Class Codes: G01N 3/08 by applying steady tensile or compressive forces G01N3/28 takes precedence

Abstract

A system and method to expand capabilities of simulation and durability testing of a specimen under test utilizing a virtual signal that is generated by combining the actual measured signal from a transducer with a supplemental or simulated signal created by a function based on position, load or another known or measurable parameter. This virtual signal may then be inserted into a control loop to adapt the system to this new, calculated or combined signal.

Claims

1. A system for applying loads to a test specimen, the system comprising:

a controller;

an actuator operatively coupled to the controller to operate based on control signals therefrom and adapted to apply loads or control displacement of a test specimen;

one or more transducers that provide signals to the controller indicative of at least one of measured loads or measured displacements on the test specimen; and

wherein the controller is adapted to control said actuator based on signals from at least one of the one or more transducers and a predetermined representation of additional aspects of the test specimen for generating at least one of a simulated load or a simulated displacement.

2. The system of claim 1 wherein the controller controls the actuator based on input from at least one of the one or more transducers within a predetermined linear operable range.

3. The system of claim 1 wherein the controller includes a representation of additional aspects of the test specimen according to historical measurement data.

4. The system of claim 1 wherein the representation of the controller further comprises multiple parameters whereby more than one actuator may be controlled by the controller based on a single representation.

5. The system of claim 1 wherein the controller comprises more than one representation.

6. The system of claim 5 wherein the stored representations representation of additional aspects of the test specimen further comprise comprises logical operators in order to engage additional representations.

7. The system of claim 6 wherein the engaging of additional representations by use of logical operators allow uninterrupted test of the test specimen.

21. The system of claim 1, wherein the test specimen comprises one or more processors and one or more internal sensors.

8. A method for applying loads to a test specimen, the method comprising:

making one or more measurements on a test specimen of at least one of one or more loads or one or more displacements;

controlling an actuator coupled to the test specimen to apply at least one of one or more loads or one or more displacements on the test specimen by combining information indicative of the measurements with corresponding simulated information representative of additional aspects of the test specimen, to produce virtual representations of additional aspects of at least one of loads or displacements that are used to control the actuator.

9. The method of claim 8 wherein controlling by combining information indicative of the measurements with simulated information includes parameters determined through historical data.

10. The method of claim 8 wherein the simulated information includes more than one function.

11. The method of claim 10 wherein the functions further comprise logical operators in order to engage additional functions.

12. The method of claim 11 wherein the additional functions are engaged so as to allow uninterrupted test of the specimen.

13. The method of claim 11 wherein the test specimen is an orthopedic test specimen.

14. An orthopedic test system for applying loads to a test specimen, the system comprising:

a controller;

an actuator operatively coupled to the controller to operate based on control signals therefrom and adapted to apply loads or control displacement of an orthopedic test specimen;

one or more transducers, selected from among one or more load transducers and one or more displacement transducers, wherein the transducers provide signals to the controller indicative of measured loads or displacements on the orthopedic test specimen; and

wherein the controller is adapted to control said actuator based on signals from at least one of the one or more transducers and a representation of additional aspects of the orthopedic test specimen for generating simulated loads and/or displacements.

15. The orthopedic test system of claim 14 wherein the controller controls the actuator based on input from at least one of the one or more transducers within a predetermined linear operable range.

16. The orthopedic test system of claim 14 wherein the controller includes a representation of additional aspects of the orthopedic test specimen according to historical measurement data.

17. The orthopedic test system of claim 14 wherein the representation of the controller further comprises multiple parameters whereby more than one of the one or more transducers may be controlled by the controller based on a single representation.

18. The orthopedic test system of claim 14 wherein the controller comprises more than one representation.

19. The orthopedic test system of claim 18 wherein the representations further comprise logical operators in order to engage additional representations.

20. The orthopedic test system of claim 19 wherein the engaging of additional representations by use of logical operators allow uninterrupted test of the orthopedic test specimen.