Angular accelerometers are described, as are systems employing such accelerometers. The angular accelerometers may include a proof mass and rotational acceleration detection beams directed toward the center of the proof mass. The angular accelerometers may include sensing capabilities for angular acceleration about three orthogonal axes. The sensing regions for angular acceleration about one of the three axes may be positioned radially closer to the center of the proof mass than the sensing regions for angular acceleration about the other two axes. The proof mass may be connected to the substrate though one or more anchors.

A micromechanical sensor comprising a substrate (5) and at least one mass (6) which is situated on the substrate (5) and which moves relative to the substrate (5) is used to detect motions of the sensor due to an acceleration force and/or Coriolis force which occur(s). The mass (6) and the substrate (5) and/or two masses (5, 7) which move toward one another are connected by at least one bending spring device (6). The bending spring device (6) has a spring bar (9) and a meander (10), provided thereon, having a circle of curvature (K1; K6; K8; K9; K11) whose midpoint (MP1; MP6; MP8; MP9; MP11) and radius of curvature (r1; r6; r8; r9; r11) are inside the meander (10). For reducing stresses that occur, in addition to the radius of curvature (r1; r6; r8; r9; r11) having the inner midpoint (MP1; MP6; MP8; MP9; MP11), the meander (10) has at least one further radius of curvature (r2; r3; r4; r5; r7; r10) having a midpoint (MP2; MP3; MP4; MP5; MP7; MP10) outside the meander (10). The at least one further radius of curvature (r2; r3; r4; r5; r7; r10) is situated between the meander (10) and the spring bar (9).

The gyroscope-free accelerometer based inertial sensor allows for instantaneous (not time-recursive) measurement of angular velocity, angular acceleration of the rigid body, and linear acceleration of any point on the rigid body. The analytical solution to obtain orientation measurements (angular velocity and angular acceleration) does not require knowledge of body dynamics. Measurement of the rigid body angular acceleration can be used to estimate angular velocity in sensor fusion of various inertial and non-inertial sensor. For a body moving on ground with a point of contact with zero relative acceleration, the sensor can compensate for non-gravitational, dynamic acceleration, thus, is capable of separating gravity from motion. The presented accelerometer-magnetometer based sensor can uniquely measure the orientation between two bodies with a point of contact with zero relative acceleration (e.g. a rotating joint).

A rotary angle detecting device is provided, including a fixed portion, a rotary module, a sensing module, and a permeability member. The rotary module includes a rotary shaft pivotally connected to the fixed portion, and can rotate around a main axis relative to the fixed portion. The sensing module is configured to detect the motion state of the rotary shaft relative to the fixed portion. The sensing module includes a magnetic force sensor and a magnetic member corresponding to the magnetic force sensor. The magnetic member can rotate relative to the magnetic force sensor. The permeability member is disposed between the sensing module and the rotary module.

An angular acceleration sensor includes a planar surface extending along an X-Y plane, a fixed portion, a weight, a beam, and piezoresistors. The weight is supported by the fixed portion. The beam extends along an Y-axis and is connected to the fixed portion and the weight. The beam includes through-holes extending therethrough in a Z-axis direction and protrusions protruding in an X-axis direction. The positions of the piezoresistors in the Y-axis direction overlap those of the through-holes and are displaced from those of the width-direction protrusions.

A hybrid MEMS microfluidic gyroscope is disclosed. The hybrid MEMS microfluidic gyroscope may include a micro-machined base enclosure having a top fluid enclosure, a fluid sensing enclosure and a bottom fluid enclosure. The hybrid MEMS microfluidic gyroscope may include a plurality of cantilevers disposed within the bottom semi-circular portion of the micro-machined base enclosure or a single membrane disposed within the bottom semi-circular portion of the micro-machined base enclosure.

An equipment fitting system that measures swings by a user of different pieces of equipment with inertial sensors, and analyzes sensor data to recommend which piece of equipment is optimal for the user from among those tested. Illustrative applications include fitting of baseball bats and golf clubs. Swing metrics calculated from sensor data may include an acceleration metric, a speed metric, and a momentum metric; these metrics may be combined into a metrics score for each piece of equipment. Other factors may be included in an overall score, such as the user's subjective score for each piece of equipment, and ratings from experts or other consumers. Users may assign the relative importance for the different factors to calculate an overall equipment score.

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.

Angular accelerometers are described, as are systems employing such accelerometers. The angular accelerometers may include a proof mass and rotational acceleration detection beams directed toward the center of the proof mass. The angular accelerometers may include sensing capabilities for angular acceleration about three orthogonal axes. The sensing regions for angular acceleration about one of the three axes may be positioned radially closer to the center of the proof mass than the sensing regions for angular acceleration about the other two axes. The proof mass may be connected to the substrate though one or more anchors.

An equipment fitting system that measures swings by a user of different pieces of equipment with inertial sensors, and analyzes sensor data to recommend which piece of equipment is optimal for the user from among those tested. Illustrative applications include fitting of baseball bats and golf clubs. Swing metrics calculated from sensor data may include an acceleration metric, a speed metric, and a momentum metric; these metrics may be combined into a metrics score for each piece of equipment. Other factors may be included in an overall score, such as the user's subjective score for each piece of equipment, and ratings from experts or other consumers. Users may assign the relative importance for the different factors to calculate an overall equipment score.