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.

An acceleration sensor circuit 1 of the invention includes an acceleration sensor 11 having a first capacitor C1 whose capacitance changes according to a position of a first movable electrode and a second capacitor C2 whose capacitance changes as opposed to the first capacitor according to a position of a second movable electrode moved together with the first movable electrode, a first circuit 15A for generating a sinusoidal AC signal of a predetermined frequency, a second circuit 12 for generating a signal according to the positions of the movable electrodes, and an arithmetic circuit 14 for analyzing data in which a signal generated by the second circuit 12 is encoded and outputting data of acceleration.

The present invention discloses a Z-axis structure of an accelerometer and a manufacturing method of the Z-axis structure. The Z-axis structure comprises a substrate, fixed electrodes and a mass block, wherein first anchor is arranged on a surface of the substrate; the fixed electrode is connected onto the corresponding first anchor at an end thereof; the fixed electrode is suspended above the substrate via the first anchor; an intermediate anchor is also arranged on the surface of the substrate; and the mass block is suspended above the fixed electrode via the intermediate anchor. In the Z-axis structure of the present invention, the fixed electrode is connected to the substrate by the first anchor, so that there is certain gap between the fixed electrode and the substrate. Because of the gap, the path for deformation to transmitting from the substrate to the fixed electrode is cut off, such that contact area between the fixed electrode and the substrate is reduced, effectively preventing the deformation of the substrate caused by changes of external stress and temperature from transmitting to the fixed electrode, and greatly reducing zero point offset of a Z-axis structure.

An inertial measurement device includes: a first inertial sensor; a first inertial sensor module in which the first inertial sensor is stored in a first package made of resin; a base having a concave portion and made of ceramic; and a lid body. The first inertial sensor module is accommodated in an accommodation space between the base and the lid body and is hermetically sealed.

The invention relates to a method for producing an acceleration sensor having a housing (1), which has a cylindrical or cubic basic shape, having at least one internal support (4) and having a sensor element (2) arranged thereon. According to the invention a sensor element (2) comprising a main body (29) having a head part (21) and an end face (24) opposing said head part (21) is premounted, by surrounding the head part (21) with at least one piezoelectric measuring element (23), a seismic composition (22) and a clamping ring (27). The end face (24) is subsequently positioned on the inner support (4) of the housing (1) in contact therewith to form a contact zone (7) between the end face (24) and the support (4). Finally, the sensor element (2) is welded in this contact zone (7) to the housing (1). The invention further relates to an acceleration sensor produced using said method.

A structure forming method according to an aspect is a structure forming method for forming a first hole and a second hole having width smaller than width of the first hole in a substrate with dry etching and forming a structure. The structure forming method includes forming an etching mask on the substrate, etching a portion of the etching mask overlapping a first hole forming region where the first hole is formed, etching a portion of the etching mask overlapping a second hole forming region where the second hole is formed, and performing the dry etching of the substrate using the etching mask as a mask.

A physical quantity sensor includes a substrate, an anchor portion, a surrounding portion, a detecting element, a moving portion, and a beam portion. The anchor portion is formed on the same side as a principal surface of the substrate and fixed to the substrate. The surrounding portion is formed on the same side as the principal surface of the substrate and surrounds the anchor portion. The detecting element detects a physical quantity as a target of detection. The moving portion is provided with at least a part of the detecting element, formed on the same side as the principal surface of the substrate, and connected to the surrounding portion. The beam portion is formed on the same side as the principal surface of the substrate and connects the anchor portion and the surrounding portion together.

A vibration sensor having a moveable mass being suspended in a suspension member and being adapted to move in response to vibrations or accelerations. The moveable mass and the suspension member are rigidly connected across one or more gaps formed by respective opposing surfaces of the moveable mass and the suspension member. The vibration sensor includes a damping arrangement having a damping substance. The moveable mass is arranged to interact directly or indirectly with the damping substance in order to reduce a mechanical resonance peak of the vibration sensor.

A combined MicroElectroMechanical structure (MEMS) includes a first piezoelectric membrane having one or more first electrodes, the first piezoelectric membrane being affixed between a first holder and a second holder; and a second piezoelectric membrane having an inertial mass and one or more second electrodes, the second piezoelectric membrane being affixed between the second holder and a third holder.

Systems and methods for filtering a micro-electromechanical system sensor rate signal with error feedback are provided. In one example, a micro-electromechanical system sensor rate signal is provided. Next, a feedback signal from a feedback loop is subtracted from the micro-electromechanical system sensor rate signal to produce a first combined signal. The first combined signal is then filtered to produce a filtered rate output. The micro-electromechanical system sensor rate signal is then subtracted from the filtered rate output to produce an error signal, wherein the error signal is used in the feedback loop to generate a feedback signal for a future time step.