A method of balancing a gimbaled system having a gimbal operatively connected with a motor configured to control a rotation of the gimbal, wherein the gimbal has predetermined compensation locations thereon. The method includes tumbling the gimbal through a gravity field using the motor, sensing motor control current data from the motor, applying a polynomial fit filter to the motor control current data to produce smoothed current data, determining from the smoothed current data an imbalance condition of the gimbal characterized by an imbalance torque and an imbalance angle, and applying an optimization algorithm to determine an optimized combination of one or more compensating weights disposed at one or more of the predetermined compensation locations, wherein the optimized combination is effective to compensate for the imbalance condition. A system for balancing the gimbaled system is al so disclosed.

A method of balancing a gimbaled system having a gimbal operatively connected with a motor configured to control a rotation of the gimbal, wherein the gimbal has predetermined compensation locations thereon. The method includes tumbling the gimbal through a gravity field using the motor, sensing motor control current data from the motor, applying a polynomial fit filter to the motor control current data to produce smoothed current data, determining from the smoothed current data an imbalance condition of the gimbal characterized by an imbalance torque and an imbalance angle, and applying an optimization algorithm to determine an optimized combination of one or more compensating weights disposed at one or more of the predetermined compensation locations, wherein the optimized combination is effective to compensate for the imbalance condition. A system for balancing the gimbaled system is al so disclosed.

A gyroscopic module comprises at least one gyroscopic rotor rotatably mounted to a support, wherein the at least one gyroscopic rotor is driven by at least one first power source and at least one gimbal frame is coupled to the support of the at least one gyroscopic rotor. The gyroscopic module comprises at least one slew bearing coupled to the at least one gimbal frame to change an orientation of the at least one gyroscopic rotor, wherein the at least one slew bearing is driven by at least one second power source mounted to the at least one gimbal frame.

A gyroscopic module comprises at least one gyroscopic rotor rotatably mounted to a support, wherein the at least one gyroscopic rotor is driven by at least one first power source and at least one gimbal frame is coupled to the support of the at least one gyroscopic rotor. The gyroscopic module comprises at least one slew bearing coupled to the at least one gimbal frame to change an orientation of the at least one gyroscopic rotor, wherein the at least one slew bearing is driven by at least one second power source mounted to the at least one gimbal frame.

A power tool includes a housing, a motor received in the housing, an output driven by the motor, and a control system. The control system includes a rotational motion sensor configured to generate a rotational motion signal that corresponds to a rotational motion of the housing about an axis, a current sensor configured to generate a motor current signal that corresponds to an amount of current drawn by the motor, and a control circuit that is configured to receive the rotational motion signal and the motor current signal and to control operation of the motor. The control circuit is configured: (a) to determine, based on the current signal, whether a detected kickback condition is likely to be false; (b) to determine, based upon the rotational motion signal, whether an uncontrolled kickback condition has occurred; and (c) to initiate one or more protective operations upon determining that an uncontrolled kickback condition has occurred and is not likely to be false.

A power tool includes a housing, a motor received in the housing, an output driven by the motor, and a control system. The control system includes a rotational motion sensor configured to generate a rotational motion signal that corresponds to a rotational motion of the housing about an axis, a current sensor configured to generate a motor current signal that corresponds to an amount of current drawn by the motor, and a control circuit that is configured to receive the rotational motion signal and the motor current signal and to control operation of the motor. The control circuit is configured: (a) to determine, based on the current signal, whether a detected kickback condition is likely to be false; (b) to determine, based upon the rotational motion signal, whether an uncontrolled kickback condition has occurred; and (c) to initiate one or more protective operations upon determining that an uncontrolled kickback condition has occurred and is not likely to be false.

A power tool includes a housing, a motor received in the housing, an output driven by the motor, and a control system. The control system includes a rotational motion sensor configured to generate a rotational motion signal that corresponds to a rotational motion of the housing about an axis, a current sensor configured to generate a motor current signal that corresponds to an amount of current drawn by the motor, and a control circuit that is configured to receive the rotational motion signal and the motor current signal and to control operation of the motor. The control circuit is configured: (a) to determine, based on the current signal, whether a detected kickback condition is likely to be false; (b) to determine, based upon the rotational motion signal, whether an uncontrolled kickback condition has occurred; and (c) to initiate one or more protective operations upon determining that an uncontrolled kickback condition has occurred and is not likely to be false.

A power tool includes a housing, a motor received in the housing, an output driven by the motor, and a control system. The control system includes a rotational motion sensor configured to generate a rotational motion signal that corresponds to a rotational motion of the housing about an axis, a current sensor configured to generate a motor current signal that corresponds to an amount of current drawn by the motor, and a control circuit that is configured to receive the rotational motion signal and the motor current signal and to control operation of the motor. The control circuit is configured: (a) to determine, based on the current signal, whether a detected kickback condition is likely to be false; (b) to determine, based upon the rotational motion signal, whether an uncontrolled kickback condition has occurred; and (c) to initiate one or more protective operations upon determining that an uncontrolled kickback condition has occurred and is not likely to be false.

An inertial sensing device comprising a circuit board provided with an inertial sensor. The inertial sensing device also comprises a base, a rotating plate and a power source assembly. The circuit board is mounted on the rotating plate, the power source assembly is mounted on the base, the rotating plate is drivingly connected to a power output shaft of the power source assembly. The circuit board rotates along with the rotating plate in a reciprocating or a continuous manner at a speed of 1 to 200 RPM. The inertial sensing device is combined with a monitored movable target under operating conditions, and transmits a collected signal to a personal navigation system to display an instantaneous geographic position of the target. The inertial sensing device is low in cost, small in size, and is capable of controlling the heading error within 1/hour to increase the accuracy of indoor navigation systems.

An inertial sensing device comprising a circuit board provided with an inertial sensor. The inertial sensing device also comprises a base, a rotating plate and a power source assembly. The circuit board is mounted on the rotating plate, the power source assembly is mounted on the base, the rotating plate is drivingly connected to a power output shaft of the power source assembly. The circuit board rotates along with the rotating plate in a reciprocating or a continuous manner at a speed of 1 to 200 RPM. The inertial sensing device is combined with a monitored movable target under operating conditions, and transmits a collected signal to a personal navigation system to display an instantaneous geographic position of the target. The inertial sensing device is low in cost, small in size, and is capable of controlling the heading error within 1/hour to increase the accuracy of indoor navigation systems.