Method for controlling smart energy devices

A method for determining a characteristic of an ultrasonic blade of an ultrasonic electromechanical system, the method comprising:

• providing an ultrasonic electromechanical system comprising an ultrasonic transducer coupled to an ultrasonic blade via an ultrasonic waveguide;
• applying, by an energy source, a power level to the ultrasonic transducer;
• determining, by a control circuit coupled to a memory, the characteristic of the ultrasonic blade, wherein determining, by a control circuit coupled to a memory, the characteristic of the ultrasonic blade comprises determining, by the control circuit coupled to the memory, a temperature of the ultrasonic blade;
• generating, by the control circuit, a temperature estimator and state space model of the temperature of the ultrasonic blade as a function of a resonant frequency of the ultrasonic electromechanical system based on a set of non-linear state space equations;
• and
• applying, by the control circuit, a Kalman filter to improve the temperature estimator and state space model;
• wherein applying, by the control circuit, a Kalman filter to improve the temperature estimator and state space model comprises applying, by the control circuit, a Kalman filter having a state variance of a state estimator of the Kalman filter defined by:
• (σk−)2=σk-12+σPk2 and
• a gain K of the Kalman filter is defined by:
• K
• =
• (
• σ
• k
• -
• )
• 2
• (
• σ
• k
• -
• )
• 2
• +
• σ
• m
• 2
• ,
• wherein σk− is defined as the state variance, σk-1 is defined as prior variance, σPk is defined as predicted variance, and σm is defined as observed variance.

A method, comprising:

• providing an ultrasonic electromechanical system comprising an ultrasonic transducer coupled to an ultrasonic blade via an ultrasonic waveguide;
• applying energy to the ultrasonic blade;
• determining a temperature of the ultrasonic blade;
• and
• generating a state space model defined by:
• [
• F
• ˙
• n
• T
• ˙
• ]
• =
• f
• ⁡
• (
• t
• ,
• T
• ⁡
• (
• t
• )
• ,
• F
• n
• (
• t
• )
• ,
• E
• ⁡
• (
• t
• )
• )
• y
• ˙
• =
• h
• ⁡
• (
• t
• ,
• T
• ⁡
• (
• t
• )
• ,
• F
• n
• (
• t
• )
• ,
• E
• ⁡
• (
• t
• )
• )
• ,
• wherein the state space model represents a rate of change of a natural frequency {dot over (F)}n of the ultrasonic electromechanical system and a rate of change of the temperature {dot over (T)} with respect to the natural frequency Fn(t), the temperature T(t), the energy E(t) applied to the ultrasonic blade, and time t, and wherein {dot over (y)} represents observability of the natural frequency Fn(t) of the ultrasonic electromechanical system, the temperature T(t) of the ultrasonic blade, the energy E(t) applied to the ultrasonic blade, and time t.

A method, comprising:

• providing an ultrasonic electromechanical system comprising an ultrasonic transducer coupled to an ultrasonic blade via an ultrasonic waveguide;
• determining a temperature of the ultrasonic blade;
• generating a temperature estimator and state space model of the temperature of the ultrasonic blade;
• and
• applying a Kalman filter having a state variance of a state estimator of the Kalman filter defined by:
• (σk−)2=σk-12+σPk2 and
• a gain K of the Kalman filter is defined by:
• K
• =
• (
• σ
• k
• -
• )
• 2
• (
• σ
• k
• -
• )
• 2
• +
• σ
• m
• 2
• ,
• wherein σk− is defined as the state variance, σk-1 is defined as prior variance, σPk is defined as predicted variance, and σm is defined as observed variance.