Linear-motion engine controller and related method

An apparatus for controlling a range of movement of a power piston coupled to an alternator in a linear-motion engine, the apparatus comprising:

• a bridge controller coupled to the alternator that compares a voltage output from the alternator to a reference voltage that corresponds to a desired range of movement of the power piston, wherein the bridge controller includes:
• a root-mean-square voltage calculator coupled to the alternator that calculates a root-mean-square voltage based on the voltage output from the alternator,
• a proportional integral derivative regulator coupled to the root-mean-square voltage calculator that receives the root-mean-square voltage and a reference voltage, and that generates a dc reference current as a function of a difference between the root-mean-square voltage and the reference voltage,
• a multiplier coupled to the proportional integral derivative regulator and the alternator that converts the dc reference current and the voltage output from the alternator into an ac reference current,
• a root-mean-square current calculator that calculates a root-mean-square current based on a current output from the alternator,
• a phase advance coupled to the multiplier and the root-mean-square current calculator that generates a third reference current that represents a phase-shifted version of the ac reference current,
• a current regulator coupled to the phase advance and the alternator that determines a duty cycle based on a difference between the third reference current and the current output from the alternator, and
• a pulse width modulator generator coupled to the current regulator that generates a plurality of control signals based on the duty cycle;
• and
• a power bridge coupled to the bridge controller and the alternator that adjusts the voltage output from the alternator, wherein the power bridge includes a plurality of switches coupled to the pulse width modulator generator and each of the plurality of switches receives one of the plurality of control signals.

An apparatus comprising:

• a linear-motion engine including:
• a power piston, and
• an alternator coupled to the power piston;
• a power bridge coupled to the alternator that adjusts a voltage output from the alternator;
• and
• a bridge controller coupled to the power bridge and the alternator that compares the voltage output from the alternator to a reference voltage corresponding to a desired range of movement of the power piston, and that generates a plurality of control signals used to control the operation of the power bridge.

An apparatus comprising:

• a linear-motion engine including:
• a power piston, and
• an alternator coupled to the power piston;
• a bridge controller coupled to the alternator that compares a voltage output from the alternator to a reference voltage that corresponds to a desired range of movement of the power piston, wherein the bridge controller includes:
• a root-mean-square voltage calculator coupled to the alternator that calculates a root-mean-square voltage based on the voltage output from the alternator,
• a proportional integral derivative regulator coupled to the root-mean-square voltage calculator that receives the root-mean-square voltage and a reference voltage, and that generates a dc reference current as a function of a difference between the root-mean-square voltage and the reference voltage,
• a multiplier coupled to the proportional integral derivative regulator and the alternator that converts the dc reference current and the voltage output from the alternator into an ac reference current,
• a root-mean-square current calculator that calculates a root-mean-square current based on a current output from the alternator,
• a phase advance coupled to the multiplier and the root-mean-square current calculator that generates a third reference current that represents a phase-shifted version of the ac reference current,
• a current regulator coupled to the phase advance and the alternator that determines a duty cycle based on a difference between the third reference current and the current output from the alternator, and
• a pulse width modulator generator coupled to the current regulator that generates a plurality of control signals based on the duty cycle;
• and
• a power bridge coupled to the bridge controller and the alternator that adjusts the voltage output from the alternator, wherein the power bridge includes a plurality of switches coupled to the pulse width modulator generator and each of the plurality of switches receives one of the plurality of control signals.

A method for controlling a range of movement of a power piston coupled to an alternator in a linear-motion engine, the method comprising:

• measuring a voltage output from the alternator;
• controlling the range of motion of the power piston by controlling the voltage output from the alternator;
• measuring a current output from the alternator;
• generating a plurality of control signals based on the voltage output from the alternator and the current output from the alternator;
• and
• controlling the voltage output from the alternator based on the plurality of control signals.

A method for controlling a range of movement of a power piston coupled to an alternator in a linear-motion engine, the method comprising:

• measuring a voltage output from the alternator;
• controlling the range of motion of the power piston by controlling the voltage output from the alternator;
• and
• calculating a root-mean-square voltage from the voltage output from the alternator.

A method for controlling a range of movement of a power piston coupled to an alternator in a linear-motion engine, the method comprising:

• measuring a voltage output from the alternator;
• calculating a root-mean-square voltage from the voltage output from the alternator;
• generating a dc reference current based on the root-mean-square voltage and a reference voltage;
• measuring a current output from the alternator;
• calculating a root-mean-square current from the current output from the alternator;
• generating an ac reference current-based on the dc reference current and the root-mean-square current;
• generating a third reference current based on the ac reference current and the root-mean-square current;
• generating a duty cycle based on the third reference current and the current output from the alternator;
• generating a plurality of control signals based on the duty cycle;
• and
• controlling the voltage output from the alternator based on the plurality of control signals.