A system that measures a swing of equipment (such as a bat or golf club) with inertial sensors, and analyzes sensor data to create a rotational profile. Swing analysis may use a two-lever model, with a body lever from the center of rotation to the hands, and an equipment lever from the hands to the sweet spot of the equipment. The rotational profile may include graphs of rates of change of the angle of the body lever and of the relative angle between the body lever and the equipment lever, and a graph of the centripetal acceleration of the equipment. These three graphs may provide insight into players' relative performance. The timing and sequencing of swing stages may be analyzed by partitioning the swing into four phases: load, accelerate, peak, and transfer. Swing metrics may be calculated from the centripetal acceleration curve and the equipment/body rotation rate curves.

An accelerometer arrangement and method are described for determining accelerations of an inground tool. First and second triaxial accelerometers are supported such that a normal sensing axis of the first triaxial accelerometer is at least generally orthogonal to the normal sensing axis of the second triaxial accelerometer for determining the accelerations along the three orthogonal axes based on a combination of sensing axis outputs from one or both of the triaxial accelerometers. A weaker sensing axis of one triaxial accelerometer can be supported at least approximately normal to a weaker sensing axis of another triaxial accelerometer such that the weaker axes are not used. The triaxial accelerometers can be supported such that one axis of one accelerometer can be redundant with respect to another axis of another accelerometer. One triaxial accelerometer can be mounted on a tilted plane with respect to another triaxial accelerometer.

Operation of a hubodometer includes orbiting detection and cancelation. In particular, in a hubodometer having a housing that rotates relative to a pendulous assembly, such operation includes detecting, by at least one orbiting sensor operatively connected to the pendulous assembly, an orbiting condition of the pendulous assembly, the orbiting condition being at least partly defined by an orbiting direction. Thereafter, and responsive to the detection of the orbiting condition, operation of the hubodometer further comprises applying, by an electric actuator operatively connected to the pendulous assembly, a countervailing force to the pendulous assembly in a direction opposite the orbiting direction. Through application of the countervailing force, the orbiting condition may be canceled.

A micromechanical inertial sensor. The inertial sensor includes a first sensor element for measuring an inertial variable in a first frequency band, and a second sensor element for measuring a periodic acceleration in a second frequency band. The second frequency band is at least partially above the first frequency band.

An inertial sensor module includes a first sensor, a second sensor, and a processing circuit. The first sensor detects, with a first sensitivity, a first physical quantity at a first detection axis and a second physical quantity at a second detection axis. The second sensor detects, with a second sensitivity different from the first sensitivity, a third physical quantity at a third detection axis with a higher accuracy than the first sensor. The processing circuit performs arithmetic processing that is processing of converting the first physical quantity and the second physical quantity at the first sensitivity and the third physical quantity at the second sensitivity into a first physical quantity, a second physical quantity, and a third physical quantity at a predetermined sensitivity.

An inertial sensor module includes: a first inertial sensor having a first axis as a detection axis; and a second inertial sensor having the first axis, a second axis, and a third axis as detection axes, in which the first inertial sensor and the second inertial sensor are separated from each other, and detection accuracy of the first inertial sensor is higher than detection accuracy of the second inertial sensor.

A physical quantity sensor includes a base, at least two arms, a movable plate, a hinge, and a physical quantity measurement element. Four quadrants of the sensor are defined by first and second orthogonal lines. The first line passes through the center of the sensor and crosses the hinge. The second line extends along the hinge. Fixed regions of the sensor are located in the first and second quadrants. No fixed regions are located in at least one of the third and fourth quadrants. The third and fourth quadrants are closer to the base than the first and second quadrants in a plan view.

A sensor module includes a circuit board, a sensor element having a detection axis along a planar direction of the circuit board, a sensor package accommodating the sensor element and mounted on the circuit board, a board land pattern used for mounting the sensor package disposed on the circuit board, and a package electrode disposed on a mounting surface of the sensor package facing the circuit board and joined to the board land pattern by a solder. A relationship of Xp≤X1 is satisfied, in which Xp is a width of the board land pattern in a first direction along the planar direction of the circuit board, and X1 is a width of the package electrode in the first direction.

A rotational sensor for measuring rotational acceleration is disclosed. The rotational sensor comprises a sense substrate; at least two proof masses, and a set of two transducers. Each of the at least two proof masses is anchored to the sense substrate via at least one flexure and electrically isolated from each other; and the at least two proof masses are capable of rotating in-plane about a Z-axis relative to the sense substrate, wherein the Z-axis is normal to the substrate. Each of the transducers can sense rotation of each proof mass with respect to the sense substrate in response to a rotation of the rotational sensor.

A sensor module includes an X-axis angular velocity sensor device that outputs digital X-axis angular velocity data, a Y-axis angular velocity sensor device that outputs digital Y-axis angular velocity data, a Z-axis angular velocity sensor device that outputs digital Z-axis angular velocity data, an acceleration sensor device that outputs digital X-axis, Y-axis, and Z-axis acceleration data, a microcontroller, a first digital interface bus that electrically connects the X-axis angular velocity sensor device, the Y-axis angular velocity sensor device, and the Z-axis angular velocity sensor device to a first digital interface, and a second digital interface bus that electrically connects the acceleration sensor device to a second digital interface.