Office of Technology Transfer – University of Michigan

Retrospective Cost Adaptive Control for Feedforward Disturbance Rejection

Technology #7132

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Dennis S. Bernstein
Managed By
Joohee Kim
Licensing Specialist, Physical Sciences & Engineering 734-764-8202

Active noise control and active vibration control seek to eliminate undesirable sounds or motion from an environment. This is done by actively generating sound waves or vibrations that attenuate the undesirable components. Examples of this concept include noise cancelling headphones, noise cancelling audio in automobile cabins, noise cancellation in air ducts within a commercial building, or vibration cancellation in buildings to eliminate building sway from the wind.

Active noise control and active vibration control can be considered disturbance rejection problems from the context of control system design. Methods of rejecting, or reducing the effect of, disturbances such as unwanted noise or vibration include feedback methods, feedforward methods, and methods based on the internal model principal. However, issues arise when little information of the disturbances and system model are known beforehand.

Adaptive, Feedforward Control for Disturbance Rejection

The technology consists of an adaptive, feedforward control algorithm that rejects disturbances with little modeling information available beforehand. The algorithm can account for narrowband, wideband, and non-periodic disturbances, requires less modeling information about the system as compared to existing commercial feedforward control methods, and also presents an alternative to feedforward control architectures that require feedback neutralization. Simulation-based data support the claimed benefits. The algorithm has applications in active vibration and noise cancellation in the aerospace, automotive, consumer electronic, and building sectors.


  • Active noise control in Heating Ventilation and Air-conditioning (HVAC) systems
  • Active noise control in automotive, aerospace, and consumer electronic applications
  • Active vibration control in automotive, aerospace, and building applications


  • Reduced modeling requirements
  • Does not require feedback neutralization
  • Applicable to highly dynamic environments