An inertial measurement unit (IMU) device includes a circuit board assembly including a rigid circuit board and a flexible circuit board, an IMU sensor disposed on the rigid circuit board, and a heat preservation system. The IMU sensor is electrically connected to an external element through the flexible circuit board to transmit at least one of a signal or power between the IMU sensor and the external element. The heat preservation system includes a heat source, a heat preservation body with a receiving space to accommodate the IMU sensor, and a heat conductive member configured to transfer heat from the heat source to the IMU sensor to maintain the IMU sensor at a preset temperature. The heat conductive member includes an electrically insulating and thermally conductive silicone.

A method of creating a privacy mask from an image imaged by an imaging device in which a rotation axis of a camera and a center of a lens do not match includes measuring a distance from the camera to an object in a first imaging condition; creating a first mask for the object, and storing the distance together with the first mask; and creating a second mask for the object in a second imaging condition and correcting a position of the second mask using the first mask and the distance, wherein an imaging angle of the camera in the first imaging condition is same as the imaging angle of the camera in the second imaging condition, and wherein a position of the lens in the first imaging condition is reversed around the rotation axis from a position of the lens in the second imaging condition.

A method of creating a privacy mask from an image imaged by an imaging device in which a rotation axis of a camera and a center of a lens do not match includes measuring a distance from the camera to an object in a first imaging condition; creating a first mask for the object, and storing the distance together with the first mask; and creating a second mask for the object in a second imaging condition and correcting a position of the second mask using the first mask and the distance, wherein an imaging angle of the camera in the first imaging condition is same as the imaging angle of the camera in the second imaging condition, and wherein a position of the lens in the first imaging condition is reversed around the rotation axis from a position of the lens in the second imaging condition.

An inertial measurement unit (IMU) device includes a circuit board assembly including a rigid circuit board and a flexible circuit board, an IMU sensor disposed on the rigid circuit board, and a heat preservation system. The IMU sensor is electrically connected to an external element through the flexible circuit board to transmit at least one of a signal or power between the IMU sensor and the external element. The heat preservation system includes a heat source, a heat preservation body with a receiving space to accommodate the IMU sensor, and a heat conductive member configured to transfer heat from the heat source to the IMU sensor to maintain the IMU sensor at a preset temperature. The heat conductive member includes an electrically insulating and thermally conductive silicone.

An inertial measurement unit (IMU) device includes a circuit board assembly including a rigid circuit board and a flexible circuit board, an IMU sensor disposed on the rigid circuit board, and a heat preservation system. The IMU sensor is electrically connected to an external element through the flexible circuit board to transmit at least one of a signal or power between the IMU sensor and the external element. The heat preservation system includes a heat source, a heat preservation body with a receiving space to accommodate the IMU sensor, and a heat conductive member configured to transfer heat from the heat source to the IMU sensor to maintain the IMU sensor at a preset temperature. The heat conductive member includes an electrically insulating and thermally conductive silicone.

A contactless power supply and motor control system includes a pulse width modulator, a rotary transformer, a demodulator circuit, a motor driver, and a motor. The pulse width modulator supplies a first pulse width modulated (PWM) signal that has a duty cycle and a first amplitude. The rotary transformer receives the PWM signal. The secondary winding is rotatable relative to the primary winding and supplies a second PWM signal having the duty cycle and a second amplitude. The demodulator circuit is rotatable with the secondary winding and supplies a demodulated direct current (DC) voltage having a DC voltage amplitude. The motor driver is rotatable with the secondary winding and the demodulator circuit and controllably supplies motor current. The motor receives the motor current and rotates at a rotational speed.

An inertial measurement unit includes a sensor and a heat preservation system. The heat preservation system includes a heat preservation body and a heat source. The sensor is positioned on the heat preservation body. The heat source is configured to generate heat. The heat preservation body is configured to transfer the heat from the heat source to the sensor to maintain a preset temperature in a space surrounding the sensor.

An inertial measurement unit includes a sensor and a heat preservation system. The heat preservation system includes a heat preservation body and a heat source. The sensor is positioned on the heat preservation body. The heat source is configured to generate heat. The heat preservation body is configured to transfer the heat from the heat source to the sensor to maintain a preset temperature in a space surrounding the sensor.

A power tool operator protection system comprises a plurality of wearable position sensors configured to be worn by an operator of a handheld power tool; a power tool position sensor configured to detect the position of a handheld power tool; and processing equipment configured to generate a model of the operator based on the mutual positions of the respective wearable sensors relative to each other, the mutual positions defining the operator's posture; associate each of a plurality of limbs (32a-g) of the operator with a respective protection volume (30a-g); and based on the position and/or motion of the power tool in relation to the protection volume (30a-g) indicating an imminent danger that the working implement enters a protection volume (30a-g), generate a protection signal.

A method of creating a privacy mask from an image imaged by an imaging device in which a rotation axis of a camera and a center of a lens do not match includes measuring a distance from the camera to an object in a first imaging condition; creating a first mask for the object, and storing the distance together with the first mask; and creating a second mask for the object in a second imaging condition and correcting a position of the second mask using the first mask and the distance, wherein an imaging angle of the camera the first imaging condition is same as the imaging angle of the camera in the second imaging condition, and wherein a position of the lens in the first imaging condition is reversed around the rotation axis from a position of the lens in the second imaging condition.