Apparatus and method for adaptive closed loop control of shock testing system

An adaptive closed loop control apparatus for use in the vibrational shock testing of a test system which includes a device under test, the control apparatus supplying a drive signal to the test system in order to produce a desired transient response signal at a designated location on the device under test, wherein a response of the test system to the supplied drive signal is measured at the designated location and can be described by a test system transfer function, the control apparatus comprising:

• actuator means for applying the drive signal to the test system;
• transducer means for measuring the response signal of the test system at a designated location on the device under test;
• comparison means for comparing the measured response signal of the test system to the desired transient response signal and producing a measure thereof;
• means for producing a closed loop update of the test system transfer function which more accurately describes the test system, the update of the test system transfer function being conditioned so as to prevent its divergence;
• and
• means for producing a closed loop update of the drive signal, the update of the drive signal providing a more accurate representation of the drive signal which when applied to the test system will more accurately produce the desired response signal, wherein the updated drive signal depends on the previous drive signal and the measure produced by the comparison means which has been weighted by the update to the test system transfer function.

A method of performing adaptive closed loop control for the purpose of conducting a vibrational shock test of a test system which includes a device under test, the controller supplying a drive signal to the test system in order to produce a desired transient response signal at a designated location on the device under test, wherein a response of the test system to the supplied drive signal is measured at the designated location and can be described by a test system transfer function, the method comprising:

• comparing the measured response signal of the test system to the desired transient response signal and producing a measure thereof;
• producing a closed loop update of the test system transfer function which more accurately describes the test system, the update of the test system transfer function being conditioned so as to prevent its divergence;
• and
• producing a closed loop update of the drive signal, the update of the drive signal providing a more accurate representation of the drive signal which when applied to the test system will more accurately produce the desired response signal, wherein the updated drive signal depends on the previous drive signal and the measure produced by the comparison means which has been weighted by the update to the test system transfer function.

A method of performing adaptive closed loop control for the purpose of conducting a vibrational shock test of a test system which includes a device under test, the controller supplying a drive signal to the test system in order to produce a desired transient response signal at a designated location on the device under test, wherein a response of the test system to the supplied drive signal is measured at the designated location and can be described by a test system transfer function, the method comprising:

• applying the drive signal to the test system;
• measuring the response signal of the test system at a designated location on the device under test;
• comparing the measured response signal of the test system to the desired transient response signal and producing a measure thereof;
• producing a closed loop update of the test system transfer function which more accurately describes the test system, the update of the test system transfer function being conditioned so as to prevent its divergence;
• and
• producing a closed loop update of the drive signal, the update of the drive signal providing a more accurate representation of the drive signal which when applied to the test system will more accurately produce the desired response signal, wherein the updated drive signal depends on the previous drive signal and the measure produced by the comparison means which has been weighted by the update to the test system transfer function.