A vessel hull stabilization system includes a housing having a rotatable shaft mounted thereto, the shaft configured to connect to a fin such that the fin is located on an outside of the vessel hull and the housing is located on an inside of the vessel hull. A drive system is mounted to the housing and includes a motor and a drive element. The motor is connected to a central shaft of the drive element. The drive element includes a plurality of teeth positioned between the outer element and the central shaft such that when the motor rotates the central shaft, the plurality of teeth oscillate inwards and outwards to interact with teeth in the outer element and thereby cause rotation of a fin shaft connected to the outer element or to the gear having the oscillating teeth. A controller receives sensor readings to determine control signals to send to the motor(s) to impart rotation of the fin.

A vessel hull stabilization system includes a housing having a rotatable shaft mounted thereto, the shaft configured to connect to a fin such that the fin is located on an outside of the vessel hull and the housing is located on an inside of the vessel hull. A drive system is mounted to the housing and includes a motor and a drive element. The motor is connected to a central shaft of the drive element. The drive element includes a plurality of teeth positioned between the outer element and the central shaft such that when the motor rotates the central shaft, the plurality of teeth oscillate inwards and outwards to interact with teeth in the outer element and thereby cause rotation of a fin shaft connected to the outer element or to the gear having the oscillating teeth. A controller receives sensor readings to determine control signals to send to the motor(s) to impart rotation of the fin.

A method for automatically reducing the power consumed by devices from a power source having a limited amount of power. The method includes determining with a control system which of the devices is consuming the power. The method further includes identifying a candidate device among the devices to tentatively control to reduce the power consumed by the candidate device. The method further includes accessing a power control model, where the power control model includes pairings of the candidate device with complementary devices among the devices, and where the devices in each of the pairings consume the power in a related pattern. The method further includes controlling the candidate device to reduce the power consumed thereby only when each of the complementary devices in each of the pairings in the power control model are determined to be in a non-power consuming state.

The propulsion unit includes a frame construction having an upper portion forming a support arm protruding from a hull of the vessel and a lower portion forming a longitudinal compartment provided with a propeller shaft having at least one propeller attached thereto, and a first electric motor driving the propeller shaft. The method includes measuring vibrations of the propulsion unit with at least one measuring device, forming a first auxiliary torque control signal based on the measured vibration signal, adding the first auxiliary torque control signal to a first torque control signal produced by a first torque controller of the first electric motor. The first auxiliary torque signal acts against the measured vibrations.

The propulsion unit includes a frame construction having an upper portion forming a support arm protruding from a hull of the vessel and a lower portion forming a longitudinal compartment provided with a propeller shaft having at least one propeller attached thereto, and a first electric motor driving the propeller shaft. The method includes measuring vibrations of the propulsion unit with at least one measuring device, forming a first auxiliary torque control signal based on the measured vibration signal, adding the first auxiliary torque control signal to a first torque control signal produced by a first torque controller of the first electric motor. The first auxiliary torque signal acts against the measured vibrations.

Embodiments of the present invention are directed to a modular, biomimetic, underwater vehicle capable of propulsion using one or more tail undulation methods, such as anguilliform or carangiform propulsion methods.

Embodiments of the present invention are directed to a modular, biomimetic, underwater vehicle capable of propulsion using one or more tail undulation methods, such as anguilliform or carangiform propulsion methods.

A vessel hull stabilization system includes a housing having a rotatable shaft mounted thereto, the shaft configured to connect to a fin such that the fin is located on an outside of the vessel hull and the housing is located on an inside of the vessel hull. A drive system is mounted to the housing and includes a motor and a drive element. The motor is connected to a central shaft of the drive element. The drive element includes a plurality of teeth positioned between the outer element and the central shaft such that when the motor rotates the central shaft, the plurality of teeth oscillate inwards and outwards to interact with teeth in the outer element and thereby cause rotation of a fin shaft connected to the outer element or to the gear having the oscillating teeth. A controller receives sensor readings to determine control signals to send to the motor(s) to impart rotation of the fin.

A vessel hull stabilization system includes a housing having a rotatable shaft mounted thereto, the shaft configured to connect to a fin such that the fin is located on an outside of the vessel hull and the housing is located on an inside of the vessel hull. A drive system is mounted to the housing and includes a motor and a drive element. The motor is connected to a central shaft of the drive element. The drive element includes a plurality of teeth positioned between the outer element and the central shaft such that when the motor rotates the central shaft, the plurality of teeth oscillate inwards and outwards to interact with teeth in the outer element and thereby cause rotation of a fin shaft connected to the outer element or to the gear having the oscillating teeth. A controller receives sensor readings to determine control signals to send to the motor(s) to impart rotation of the fin.

A drain plug for a recreational boat includes a position sensor and an alarm to detect the operating condition of the drain plug and provide a signal indicating that the plug is in an open position. The drain plug includes a drain plug body and a cap. The cap is connected to the drain plug body in such a manner as to be inseparable from the drain plug body.