Technological Resources Pty. Limited

John Winterflood

Frank Joachim Van Kann

Frank Joachim Kann

Anthony Gordon Mann

A gravity gradiometer is disclosed which has a sensor in the form of bars (and) which are supported on a mounting () which has a first mount section () and a second mount section (). A first flexure web () pivotally couples the first and second mount sections about a first axis. The second mount has a first part (), a second part () and a third part (). The parts (and) are connected by a second flexure web () and the parts (and) are connected by a third flexure web (). The bars (and) are located in housings (and) and form a monolithic structure with the housings (and) respectively. The housings (and) are connected to opposite sides of the second mount section. The bars (and) are connected to their respective housings by flexure webs (). Transducers () are located in proximity to the bars for detecting movement of the bars to in turn enable the gravitational gradient tensor to be measured.

Gravity gradiometer

A gravity gradiometer is disclosed which has a sensor in the form of bars (and) which are supported on a mounting () which has a first mount section () and a second mount section (). A first flexure web () pivotally couples the first and second mount sections about a first axis. The second mount has a first part (), a second part () and a third part (). The parts (and) are connected by a second flexure web () and the parts (and) are connected by a third flexure web (). The bars (and) are located in housings (and) and form a monolithic structure with the housings (and) respectively. The housings (and) are connected to opposite sides of the second mount section. The bars (and) are connected to their respective housings by flexure webs (). Transducers () are located in proximity to the bars for detecting movement of the bars to in turn enable the gravitational gradient tensor to be measured. The sensor masses not only serve to provide measurements of the gravity gradient tensor but also provide signals indicative of angular movement of the mounting and therefore form one of a plurality of angular accelerometers for detecting angular movement so that control signals can be generated to stabilize the mounting ().

A gravity gradiometer is disclosed which has a sensor in the form of bars (and) which are supported on a mounting () which has a first mount section () and a second mount section (). A first flexure web () pivotally couples the first and second mount sections about a first axis. The second mount has a first part (), a second part () and a third part (). The parts (and) are connected by a second flexure web () and the parts (and) are connected by a third flexure web (). The bars (and) are located in housings (and) and form a monolithic structure with the housings (and) respectively. The housings (and) are connected to opposite sides of the second mount section. The bars (and) are connected to their respective housings by flexure webs (). Transducers () are located in proximity to the bars for detecting movement of the bars to in turn enable the gravitational gradient tensor to be measured. The first mount section () has cut-outs () and the second mount section () has lugs () which pass through the cut-outs for connecting the first and second mount sections (and) in a Dewar ().

A gravity gradiometer is disclosed which has a sensor in the form of bars (and) which are supported on a mounting () which has a first mount section () and a second mount section (). A first flexure web () pivotally couples the first and second mount sections about a first axis. The second mount has a first part (), a second part () and a third part (). The parts (and) are connected by a second flexure web () and the parts (and) are connected by a third flexure web (). The bars (and) are located in housings (and) and form a monolithic structure with the housings (and) respectively. The housings (and) are connected to opposite sides of the second mount section. The bars (and) are connected to their respective housings by flexure webs (). Transducers () are located in proximity to the bars for detecting movement of the bars to in turn enable the gravitational gradient tensor to be measured. First and second feedback controllers are provided for monitoring disturbances of an external platform and an internal platform which mount the gradiometer for producing forces to stabilise the sensor.

A gravity gradiometer is described which comprises a pair of sensor bars arranged in housings. Transducers are arranged adjacent the bars for measuring movement of the bars in response to the gravity gradient tensor. At least one of the transducers has a sensing coil and a capacitor plate having a concentric arrangement with the sensing coil for providing one plate of a capacitor used in a balancing circuit for measuring the balance of the sensor mass.

A gravity gradiometer is disclosed which has a sensor in the form of bars (and) which are supported on a mounting () which has a first mount section () and a second mount section (). A first flexure web () pivotally couples the first and second mount sections about a first axis. The second mount has a first part (), a second part () and a third part (). The parts (and) are connected by a second flexure web () and the parts (and) are connected by a third flexure web (). The bars (and) are located in housings (and) and form a monolithic structure with the housings (and) respectively. The housings (and) are connected to opposite sides of the second mount sectionThe bars (and) are connected to their respective housings by flexure webs (). Transducers () are located in proximity to the bars for detecting movement of the bars to in turn enable the gravitational gradient tensor to be measured. An actuator is provided for moving the mount to stabilize the mount. The actuator comprises a hollow disc housing () which defines a chamber (). A coil plate () is located in the chamber () and supports windings (Wand W). A tube () supports a hollow rod () to minimize flux leakage from the windings (Wand W). Lead wires for the windings pass through the rod () to the windings (Wand W) mounted on the support plate ().

Actuatory and gravity gradiometer

A gravity gradiometer and method for forming a pivot flexure web for a gradiometer is disclosed. The gradiometer has measurement barssupported in housingsandand transducersfor measuring movement of the bars to provide an indication of the gravity gradient tensor. The barsare mounted on flexure webs. The webs are formed in separate elements to the housing and bars.

A gravity gradiometer is disclosed which has a sensor in the form of bars (and) which are supported on a mounting () which has a first mount section () and a second mount section (). A first flexure web () pivotally couples the first and second mount sections about a first axis. The second mount has a first part (), a second part () and a third part (). The parts (and) are connected by a second flexure web () and the parts (and) are connected by a third flexure web (). The bars (and) are located in housings (and) and form a monolithic structure with the housings (and) respectively. The housings (and) are connected to opposite sides of the second mount section. The bars (and) are connected to their respective housings by flexure webs (). Transducers () are located in proximity to the bars for detecting movement of the bars to in turn enable the gravitational gradient tensor to be measured. A calibration sensor is provided for sensing whether the masses are balanced at room temperature so the balance of the masses can be adjusted by adjustable screws to balance the masses for cryogenic operation of the gradiometer. The calibration sensor comprises a resonant circuit () and an oscillator (). The resonant circuit includes a capacitor () which is formed by part of the sensor mass and a space plate ().

A gravity gradiometer is disclosed which comprises a pair of sensor masses arranged in housings. Transducers are provided for measuring movement of the sensor masses in response to the gravity gradient tensor. The masses are supported for movement by a flexure web between the mass and a support and a stop comprises a pair of abutment services defined by a cut prevent movement of the sensor masses beyond the elastic limit of the flexure web.

A gradiometer is disclosed which has a pair of sensor barssupported in housings. Transducersare located adjacent the barsto detect movement of the bars in response to the gravity gradient tensor. At least one of the transducerscomprises a first coiland a second coilarranged in parallel and a switchfor proportioning current between the coilsandso as to create a virtual coil at a position D between the coilsand

A heat switchis disclosed as well as a gradiometer having the heat switch. The heat switch is formed from a non-magnetic material such as a semi-conducting material. The semi-conducting material may be provided by way of a Hall effect device. The heat switches are arranged in the gradiometer on a circuit board. The circuit boardhas conducting stripswhich are connected to conducting strips on a sensorby bridges. The heat switchis connected on the opposite side of the circuit boardto the stripsand processing circuitry. A copper substrateis provided on the same side of the circuit board as the heat switchto conduct heat away from the heat switchwhen the heat switch is closed.

The present invention provides a gravity gradiometer for measuring components of the gravity gradient tensor. The gravity gradiometer comprises a housing and a gimballed support structure with at least one actuator. The gravity gradiometer further comprises at least one sensor mass arranged for movement in response to a gravity gradient. The gravity gradiometer also comprises a transducer that is arranged so that the movement of the at least one sensor mass relative to a portion of the transducer generates a transducer signal. Further, the gravity gradiometer comprises an electrical feedback loop arranged to direct an electrical signal to the actuator of the external support structure. The gravity gradiometer is arranged so that an influence of an external angular acceleration on the rotation of the housing is reduced by the actuator when the transducer generates a transducer signal effected by the external angular acceleration on the gravity gradiometer.

The present invention provides a gravity gradiometer which comprises at least one sensor mass suspended by a coupling which enables movement of the at least one sensor mass about an axis in response to a gravity gradient. Further, the gravity gradiometer comprises at least one transducer for generating an electrical signal in response to the movement of the at least one sensor mass relative to a component of the transducer and for influencing the movement of the at least one sensor mass. The gravity gradiometer also comprises electrical circuitry for receiving the electrical signal from the at least one transducer and for directing an actuating signal to the at least one transducer so that in use the at least one transducer functions as sensor and actuator.

Growing community of inventors

Nedlands, Australia

John Winterflood