An inertial measurement device includes: an inertial sensor; a first signal processing circuit; a second signal processing circuit; a first communication unit and a second communication unit configured to communicate with an external device; and a mode selection unit configured to select a processing mode from a plurality of modes including a first processing mode and a second processing mode. The first processing mode is a mode in which the inertial measurement device is used alone and outputs a signal processed by the first signal processing circuit from the first communication unit, and the second processing mode is a mode in which the inertial measurement device is used in a state of being coupled to another inertial measurement device, a first signal processed by the first signal processing circuit and a second signal from another inertial measurement device received from the second communication unit are subjected to a calculation process by the second signal processing circuit, and a signal subjected to the calculation process is output from the first communication unit.

An inertial measurement device includes: an inertial sensor; a first signal processing circuit; a second signal processing circuit; a first communication unit and a second communication unit configured to communicate with an external device; and a mode selection unit configured to select a processing mode from a plurality of modes including a first processing mode and a second processing mode. The first processing mode is a mode in which the inertial measurement device is used alone and outputs a signal processed by the first signal processing circuit from the first communication unit, and the second processing mode is a mode in which the inertial measurement device is used in a state of being coupled to another inertial measurement device, a first signal processed by the first signal processing circuit and a second signal from another inertial measurement device received from the second communication unit are subjected to a calculation process by the second signal processing circuit, and a signal subjected to the calculation process is output from the first communication unit.

A vehicle-position monitoring system includes liquid-capacitive inclinometer sensor, configured to provide a measurement of grade (θ.sub.grade) of a surface over which a vehicle travels, and an accelerometer to measure acceleration of the vehicle along a principal axis (a.sub.x) of the vehicle along the surface. Direct measurement of the grade (θ.sub.grade) provides a position-tracking system with accurate information to extract acceleration due to motoring and braking (a.sub.MB) from acceleration experienced along the principal axis and track vehicle position without regard to wheel diameter calibration.

A vehicle-position monitoring system includes liquid-capacitive inclinometer sensor, configured to provide a measurement of grade (θ.sub.grade) of a surface over which a vehicle travels, and an accelerometer to measure acceleration of the vehicle along a principal axis (a.sub.x) of the vehicle along the surface. Direct measurement of the grade (θ.sub.grade) provides a position-tracking system with accurate information to extract acceleration due to motoring and braking (a.sub.MB) from acceleration experienced along the principal axis and track vehicle position without regard to wheel diameter calibration.

Disclosed herein are systems and methods for calculating angular acceleration based on inertial data using two or more inertial measurement units (IMUs). The calculated angular acceleration may be used to estimate a position of a wearable head device comprising the IMUs. Virtual content may be presented based on the position of the wearable head device. In some embodiments, a first IMU and a second IMU share a coincident measurement axis.

Disclosed herein are systems and methods for calculating angular acceleration based on inertial data using two or more inertial measurement units (IMUs). The calculated angular acceleration may be used to estimate a position of a wearable head device comprising the IMUs. Virtual content may be presented based on the position of the wearable head device. In some embodiments, a first IMU and a second IMU share a coincident measurement axis.

According to one embodiment, a power control circuit includes a converter, a signal generating circuit, an estimation unit, and a controller. The converter includes a switching circuit and is configured to transform an output voltage from a power generator. The signal generating circuit is configured to transmit a signal to the switching circuit. The estimation unit is configured to determine a switching operation condition based on vibration information indicative of a vibration applied to the power generator. The controller is configured to control an operation of the switching circuit based on the determined switching operation condition.

According to one embodiment, a power control circuit includes a converter, a signal generating circuit, an estimation unit, and a controller. The converter includes a switching circuit and is configured to transform an output voltage from a power generator. The signal generating circuit is configured to transmit a signal to the switching circuit. The estimation unit is configured to determine a switching operation condition based on vibration information indicative of a vibration applied to the power generator. The controller is configured to control an operation of the switching circuit based on the determined switching operation condition.

An example system comprising: a microelectromechanical system (MEMS) vibrating beam accelerometer (VBA) comprising: a proof mass; and a first resonator mechanically coupled to the proof mass; a first electrode configured to apply a force to the proof mass.

Systems and methods for determining a swing angle of a swing boom of a vehicle are provided. Sensor data is received from sensors disposed on a swing boom and a body of a vehicle. It is determined whether the swing boom is static or moving relative to the body based on the sensor data. In response to determining that the swing boom is static, the received sensor data is corrected based on an observed swing angle and an estimated swing angle is calculated based on the corrected sensor data. In response to determining that the swing boom is moving, the estimated swing angle is calculated based on the received sensor data. The estimated swing angle is output.