Loading patent…
AssigneeCambridge Enterprise Limited
InventorsAshwin Seshia, Xudong Zou
Estimating the term…
A gravimeter or inertial sensor system and method of operating such a system is provided. The system comprises a variable frequency signal source (100, 101, 102) configured to provide first and second signals, a resonant sensor (103) connected to receive the first signal, a phase comparator (111) connected to the output of the resonant sensor and to receive the second signal, and a controller (114) connected to the phase comparator. In a first mode, the controller controls the desired frequency of the signals from the variable frequency signal source based on a value of the phase comparator output signal to lock the frequency of the input signals to a resonant frequency of the resonant sensor. In a second mode, the controller disconnects from the variable frequency signal source and records an open loop output signal indicative of the physical parameter to be measured based on the response of the resonant sensor.
A gravimeter or inertial sensor system, comprising:
A system according to any one of the preceding claims, wherein the variable frequency signal source is programmable.
A system according to any one of the preceding claims, wherein the variable frequency signal source comprises a signal splitter, wherein the signal splitter generates at least the first and second input signals.
A system according to any one of the preceding claims, comprising an amplifier connected between the resonant sensor and the phase or amplitude comparator.
A system according to any one of the preceding claims, comprising a phase shifter connected between the second port of the variable frequency signal source and the phase comparator.
A system according to any one of the preceding claims, wherein the variable frequency signal source comprises a third port providing a third input signal having the desired frequency, and comprises a feed through signal canceller connected in parallel to the resonant sensor, between the third port of the variable frequency signal source and the amplifier.
A system according to any one of the preceding claims, comprising a second low pass filter connected between the phase comparator and the controller.
A system according to any one of the preceding claims, comprising an analogue-to-digital convertor connected between the phase or amplitude comparator and the controller.
A system according to any one of the preceding claims, comprising an amplitude comparator connected in parallel to the phase comparator, the amplitude comparator being connected between an output of the resonant sensor and the controller and between the second port of the variable frequency signal source and the controller.
A system according to any one of the preceding claims, wherein the controller comprises a memory.
A system according to any one of the preceding claims, wherein the controller comprises a data logger.
A system according to any one of the preceding claims, wherein the resonant sensor comprises at least one movable mechanical microstructure.
A method of operating a gravimeter or inertial sensor system, the gravimeter or inertial sensor system comprising a resonant sensor, the resonant sensor having a resonant frequency or amplitude response that is dependent on a physical parameter to be measured, and a variable frequency signal source connected to an input of the resonant sensor and configured to provide an input signal having a desired frequency to the input of the resonant sensor, the method comprising:
Dependencies are inferred from the claim text.