Patent classifications
G01P15/13
Resonant accelerometer
In certain embodiments, an accelerometer is a microelectromechanical systems (MEMS) device including a proof mass, an anchor located in an opening defined by a body of the proof mass, a spring, a drive electrode, and a sense beam. The spring and the proof mass form a spring system suspended from the anchor. The sense beam oscillates at a particular resonance frequency based on application of a signal to the drive electrode. The MEMS device further includes a support structure coupled to the anchor. The support structure operates as a stress decoupling area and includes a support beam, with the spring corresponding to an end of the support beam that has a reduced thickness. The sense beam has a first end attached to the proof mass and a second end attached to the support beam such that the sense beam is orthogonal to the support beam.
Resonant accelerometer
In certain embodiments, an accelerometer is a microelectromechanical systems (MEMS) device including a proof mass, an anchor located in an opening defined by a body of the proof mass, a spring, a drive electrode, and a sense beam. The spring and the proof mass form a spring system suspended from the anchor. The sense beam oscillates at a particular resonance frequency based on application of a signal to the drive electrode. The MEMS device further includes a support structure coupled to the anchor. The support structure operates as a stress decoupling area and includes a support beam, with the spring corresponding to an end of the support beam that has a reduced thickness. The sense beam has a first end attached to the proof mass and a second end attached to the support beam such that the sense beam is orthogonal to the support beam.
ACCELERATION SENSOR
Provided is an acceleration sensor capable of realizing a simultaneous operation method of signal detection and servo control in place of a time-division processing method, by an MEMS process in which a manufacturing variation is large.
The acceleration sensor is an MEMS capacitive acceleration sensor and has capacitive elements for signal detection and capacitive elements for servo control different from the capacitive elements for the signal detection. A voltage to generate force in a direction reverse to a detection signal of acceleration by the capacitive elements for the signal detection is applied to the capacitive elements for the servo control. Further, the acceleration sensor includes a variable capacity unit compensating for a mismatch of capacity values of the capacitive elements for the servo control at an ASIC side, detects a leak signal due to the mismatch of the capacity values in an ASIC, controls a capacity value of the variable capacity unit, on the basis of a detection result, compensates for an influence of the mismatch of the capacity values, and executes a normal signal detection/servo control simultaneous operation.
PENDULAR ACCELEROMETER SENSOR WITH CONDITIONAL CAPACITIVE DETECTION
An accelerometer sensor includes a casing, a pendulum fixed to the casing, a movable electrode carried by the pendulum and connected to a detection circuit, a first electrode and a second electrode rigidly attached to the casing to form, with the moving electrode, two capacitors of variable capacitance depending on a distance between the electrodes. The accelerometer sensor further includes a control unit that carries out detection operations to measure the variable capacitances of the capacitors. The control unit also performs a control operation of the movable electrode depending on the capacitances measured by applying a logic signal for controlling a switch for selective connection of the fixed electrodes to an excitation circuit delivering a control signal to the fixed electrodes in order to keep the pendulum in a predetermined position.
MEMS vibrating beam accelerometer with built-in test actuators
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.
Multilayer magnetic circuit assembly
The disclosure describes a magnetic circuit assembly that includes a magnet assembly and an excitation ring. The magnet assembly defines an input axis and includes a pole piece and a magnet underlying the pole piece. The excitation ring includes a base and an outer ring positioned around the magnet assembly. The base includes a platform layer underlying the magnet and a base layer underlying the platform layer. The outer ring overlies the base layer. An inner portion of the outer ring faces the magnet assembly and an outer portion of the outer ring is configured to couple to an outer radial portion of a proof mass assembly. The pole piece and the platform layer include a high magnetic permeability material.
TEMPERATURE DEPENDENT ACCELERATION CURRENT SOURCE CIRCUITRY
Systems, methods, and circuitries are provided for generating an acceleration current in response to a threshold temperature being reached. In one example, temperature based acceleration current source circuitry includes a first temperature sensitive device, a second temperature sensitive device, differential trigger circuitry, and an acceleration current source. The first temperature sensitive device is configured to generate a first signal that varies responsive to temperature changes at a first rate. The second temperature sensitive device is configured to generate a second signal that varies responsive to temperature changes at a second rate. The differential trigger circuitry is configured to generate a trigger signal based on a difference between the first signal and the second signal. The acceleration current source circuitry is configured to output an acceleration current in response to the trigger signal.
High performance micro-electro-mechanical systems accelerometer
There is provided a resonant sensor comprising: a substrate; a proof mass suspended from the substrate by one or more flexures to allow the proof mass to move relative to the frame along a sensitive axis; a first and a second resonant element connected between the frame and the proof mass; wherein the proof mass is positioned between the first and the second resonant element along the sensitive axis, and wherein the first and the second resonant elements have a substantially identical structure to one another; and drive and sensing circuitry comprising: a first electrode assembly coupled to first drive circuitry configured to drive the first resonant element in a first mode; a second electrode assembly coupled to second drive circuitry configured to drive the second resonant element in a second mode, different to the first mode; and a sensing circuit configured to determine a measure of acceleration.
Single proof mass based three-axis accelerometer
The present invention discloses a three-axis accelerometer. The three-axis accelerometer comprises: a substrate; at least one anchor block fixedly disposed on the substrate; a first X-axis electrode, a second X-axis electrode, a first Y-axis electrode, a second Y-axis electrode, a first Z-axis electrode and a second Z-axis electrode all fixedly disposed on the substrate; a framework suspended above the substrate and comprising a first beam column, a second beam column disposed opposite to the first beam column and at least one connecting beam connecting the first beam column and the second beam column; a proof mass suspended above the substrate; and at least one elastic connection component configured to elastically connect to the at least anchor block, the connecting beam, and the proof mass. The three-axis accelerometer can realize high-precision acceleration detection on three axes with only one proof mass, and in particular, can provide a fully differential detection signal for the Z axis, thereby greatly improving detection precision.
Single proof mass based three-axis accelerometer
The present invention discloses a three-axis accelerometer. The three-axis accelerometer comprises: a substrate; at least one anchor block fixedly disposed on the substrate; a first X-axis electrode, a second X-axis electrode, a first Y-axis electrode, a second Y-axis electrode, a first Z-axis electrode and a second Z-axis electrode all fixedly disposed on the substrate; a framework suspended above the substrate and comprising a first beam column, a second beam column disposed opposite to the first beam column and at least one connecting beam connecting the first beam column and the second beam column; a proof mass suspended above the substrate; and at least one elastic connection component configured to elastically connect to the at least anchor block, the connecting beam, and the proof mass. The three-axis accelerometer can realize high-precision acceleration detection on three axes with only one proof mass, and in particular, can provide a fully differential detection signal for the Z axis, thereby greatly improving detection precision.