Patents Assigned to Atlantic Inertial Systems Limited
  • Patent number: 10161957
    Abstract: A method for closed loop operation of a capacitive accelerometer comprising: a proof mass; first and second sets of both fixed and moveable capacitive electrode fingers, interdigitated with each other; the method comprising: applying PWM drive signals to the fixed fingers; sensing displacement of the proof mass and changing the mark:space ratio of the PWM drive signals, to provide a restoring force on the proof mass that balances the inertial force of the applied acceleration and maintains the proof mass at a null position; detecting when the mark:space ratio for the null position is beyond a predetermined upper or lower threshold; and further modulating the PWM drive signals by extending or reducing x pulses in every y cycles, where x>1 and y>1, to provide an average mark:space ratio beyond the upper or lower threshold without further increasing or decreasing the mark length of the other pulses.
    Type: Grant
    Filed: March 17, 2015
    Date of Patent: December 25, 2018
    Assignee: ATLANTIC INERTIAL SYSTEMS, LIMITED
    Inventors: Kevin Townsend, Michael Terence Durston
  • Patent number: 10135454
    Abstract: A successive approximation Analog to Digital Converter (ADC), comprising: a sample and hold device arranged to sample and hold an input signal at the beginning of a conversion cycle; a successive approximation register that sequentially builds up a digital output from its most significant bit to its least significant bit; a digital to analog converter that outputs a signal based on the output of the successive approximation register; a comparator that compares the output of the digital to analog converter with an output of the sample and hold device and supplies its output to the successive approximation register; and a residual signal storage device arranged to store the residual signal at the end of a conversion cycle; and wherein the successive approximation ADC is arranged to add the stored residual signal from the residual signal storage device to the input signal stored on the sample and hold device at the start of each conversion cycle.
    Type: Grant
    Filed: December 3, 2015
    Date of Patent: November 20, 2018
    Assignee: ATLANTIC INERTIAL SYSTEMS LIMITED
    Inventors: Michael Terence Durston, Kevin Townsend, Douglas Robert Sitch
  • Patent number: 10101357
    Abstract: An accelerometer comprises a support, a first mass element and a second mass element, the mass elements being rigidly interconnected to form a unitary movable proof mass, the support being located at least in part between the first and second mass elements, a plurality of mounting legs securing the mass elements to the support member, at least two groups of movable capacitor fingers provided on the first mass element and interdigitated with corresponding groups of fixed capacitor fingers associated with the support, and at least two groups of movable capacitor fingers provided on the second mass element and interdigitated with corresponding groups of fixed capacitor fingers associated with the support.
    Type: Grant
    Filed: December 2, 2011
    Date of Patent: October 16, 2018
    Assignee: Atlantic Inertial Systems Limited
    Inventor: Alan Malvern
  • Patent number: 9881508
    Abstract: An aircraft ground collision detection system comprising: an object detection device for mounting on an aircraft and arranged to detect objects and output the location of each detected object; and a processor arranged to: receive the ground speed of the aircraft and the heading of the aircraft and the detected location of each detected object; predict the aircraft's path based on the ground speed and the heading; compare the predicted aircraft path with the object locations; and output an alert based on the overlap or proximity of the predicted aircraft path with the object locations. By predicting the path of the aircraft based on detected ground speed and heading, the system can accurately assess which detected objects pose a collision threat.
    Type: Grant
    Filed: December 4, 2015
    Date of Patent: January 30, 2018
    Assignee: Atlantic Inertial Systems Limited
    Inventor: Mark Silver
  • Publication number: 20180017389
    Abstract: A method of compensating for signal error is described, comprising: receiving a first signal from a first sensor, said first signal indicative of a movement characteristic; applying an error compensation to said first signal to produce an output signal; applying a variable gain factor to said error compensation; receiving a second signal from a second sensor indicative of said movement characteristic; wherein said error compensation is calculated using the difference between said output signal and said second signal, and said variable gain factor is calculated using said first signal.
    Type: Application
    Filed: January 26, 2016
    Publication date: January 18, 2018
    Applicant: Atlantic Inertial Systems Limited
    Inventors: John Keith Sheard, Nicholas Mark Faulkner
  • Publication number: 20170346497
    Abstract: A successive approximation Analogue to Digital Converter (ADC), comprising: a sample and hold device arranged to sample and hold an input signal at the beginning of a conversion cycle; a successive approximation register that sequentially builds up a digital output from its most significant bit to its least significant bit; a digital to analogue converter that outputs a signal based on the output of the successive approximation register; a comparator that compares the output of the digital to analogue converter with an output of the sample and hold device and supplies its output to the successive approximation register; and a residual signal storage device arranged to store the residual signal at the end of a conversion cycle; and wherein the successive approximation ADC is arranged to add the stored residual signal from the residual signal storage device to the input signal stored on the sample and hold device at the start of each conversion cycle.
    Type: Application
    Filed: December 3, 2015
    Publication date: November 30, 2017
    Applicant: Atlantic Inertial Systems Limited
    Inventors: Michael Terence Durston, Kevin Townsend, Douglas Robert Sitch
  • Patent number: 9709401
    Abstract: A MEMS sensor comprises a vibrating sensing structure formed from a semiconductor substrate layer (50). The semiconductor substrate layer (50) is mounted on a pedestal comprising an electrically insulating substrate layer (52) bonded to the semiconductor substrate (50) to form a rectangular sensor chip. The pedestal further comprises an electrically insulating spacer layer (54) for mounting the sensor chip to a housing. The electrically insulating spacer layer (54) is octagonal. When the vibrating sensing structure is excited into a cos 2? vibration mode pair, the quadrature bias arising from any mode frequency split is not affected by changes in temperature as a result of the octagonal spacer layer (54).
    Type: Grant
    Filed: April 30, 2014
    Date of Patent: July 18, 2017
    Assignee: Atlantic Inertial Systems Limited
    Inventor: Chris Fell
  • Patent number: 9689684
    Abstract: An inertial measurement system for a longitudinal projectile comprising: a first, roll gyro to be oriented substantially parallel to the longitudinal axis of the projectile; a second gyro and a third gyro with axes arranged with respect to the roll gyro such that they define a three dimensional coordinate system; a controller, arranged to: compute a current projectile attitude from the outputs of the first, second and third gyros, the computed attitude comprising a roll angle, a pitch angle and a yaw angle; compare the computed pitch and yaw angles with expected values for the pitch and yaw angles; calculate a roll angle error and a roll scale factor error based on the difference between the computed pitch and yaw angles and the expected pitch and yaw angles; and apply the calculated roll angle error and roll scale factor error to the output of the roll gyro.
    Type: Grant
    Filed: February 16, 2015
    Date of Patent: June 27, 2017
    Assignee: ATLANTIC INERTIAL SYSTEMS, LIMITED.
    Inventors: John Keith Sheard, Nicholas Mark Faulkner
  • Patent number: 9671422
    Abstract: A vibratory ring structure is described which comprises a ring body and at least one ring electrode secured thereto, the or each ring electrode extending over a first angular extent and: being attached to the ring body over second angular extent, wherein the first angular extent is greater than the second angular extent.
    Type: Grant
    Filed: March 13, 2013
    Date of Patent: June 6, 2017
    Assignee: Atlantic Inertial Systems Limited
    Inventors: Christopher Paul Fell, Rebecka Eley
  • Publication number: 20170153267
    Abstract: A method for closed loop operation of a capacitive accelerometer uses a single current source (62) and a single current sink (64) to apply an in-phase drive signal V1? to a first set of fixed capacitive electrode fingers and a corresponding anti-phase drive signal V2? to a second set of fixed capacitive electrode fingers. This provides a net electrostatic restoring force on the proof mass for balancing the inertial force of the applied acceleration and maintains the proof mass at a null position.
    Type: Application
    Filed: June 26, 2015
    Publication date: June 1, 2017
    Applicant: Atlantic Inertial Systems Limited
    Inventors: Kevin Townsend, Michael Durston, Douglas Sitch
  • Patent number: 9656858
    Abstract: A method of reactive ion etching a substrate 46 to form at least a first and a second etched feature (42, 44) is disclosed. The first etched feature (42) has a greater aspect ratio (depth:width) than the second etched feature (44). In a first etching stage the substrate (46) is etched so as to etch only said first feature (42) to a predetermined depth. Thereafter in a second etching stage, the substrate (46) is etched so as to etch both said first and said second features (42, 44) to a respective depth. A mask (40) may be applied to define apertures corresponding in shape to the features (42, 44). The region of the substrate (46) in which the second etched feature (44) is to be produced is selectively masked with a second maskant (50) during the first etching stage, The second maskant (50) is then removed prior to the second etching stage.
    Type: Grant
    Filed: July 21, 2014
    Date of Patent: May 23, 2017
    Assignee: ATLANTIC INERTIAL SYSTEMS LIMITED
    Inventors: Tracey Hawke, Mark Venables, Ian Sturland, Rebecka Eley
  • Publication number: 20170115117
    Abstract: A sensor comprises a substrate 16 and a sensor element 20 anchored to the substrate 16, the substrate 16 and sensor element 20 being of dissimilar materials and having different coefficients of thermal expansion, the sensor element 20 and substrate 16 each having a generally planar face arranged substantially parallel to one another, the sensor further comprising a spacer 26, the spacer 26 being located so as to space at least part of the sensor element 20 from at least part of the substrate 16, wherein the spacer 26 is of considerably smaller area than the area of the smaller of face of the substrate 16 and that of the sensor element 20.
    Type: Application
    Filed: January 6, 2017
    Publication date: April 27, 2017
    Applicant: Atlantic Inertial Systems Limited
    Inventor: Christopher Paul Fell
  • Publication number: 20170089947
    Abstract: A method for closed loop operation of a capacitive accelerometer comprising: a proof mass; first and second sets of both fixed and moveable capacitive electrode fingers, interdigitated with each other; the method comprising: applying PWM drive signals to the fixed fingers; sensing displacement of the proof mass and changing the mark:space ratio of the PWM drive signals, to provide a restoring force on the proof mass that balances the inertial force of the applied acceleration and maintains the proof mass at a null position; detecting when the mark:space ratio for the null position is beyond a predetermined upper or lower threshold; and further modulating the PWM drive signals by extending or reducing x pulses in every y cycles, where x>1 and y>1, to provide an average mark:space ratio beyond the upper or lower threshold without further increasing or decreasing the mark length of the other pulses.
    Type: Application
    Filed: March 17, 2015
    Publication date: March 30, 2017
    Applicant: Atlantic Inertial Systems Limited
    Inventors: Kevin Townsend, Michael Terence Durston
  • Patent number: 9541395
    Abstract: A sensor comprises a substrate (16) and a sensor element (20) anchored to the substrate (16), the substrate (16) and sensor element (20) being of dissimilar materials and having different coefficients of thermal expansion, the sensor element (20) and substrate (16) each having a generally planar face arranged substantially parallel to one another, the sensor further comprising a spacer (26), the spacer (26) being located so as to space at least part of the sensor element (20) from at least part of the substrate (16), wherein the spacer (26) is of considerably smaller area than the area of the smaller of face of the substrate (16) and that of the sensor element (20).
    Type: Grant
    Filed: January 4, 2013
    Date of Patent: January 10, 2017
    Assignee: Atlantic Inertial Systems Limited
    Inventor: Christopher Paul Fell
  • Patent number: 9494426
    Abstract: A vibratory gyroscope is provided comprising a plurality of secondary pickoff transducers which are each sensitive to the secondary response mode, wherein: at least two of the secondary pickoff transducers comprise skew transducers designed to be sensitive to the primary mode which produce an induced quadrature signal in response thereto. A method of using the gyroscope is provided comprising the steps of arranging electrical connections between the secondary pickoff transducers and a pickoff amplifier so that in use the induced quadrature signal is substantially rejected by the amplifier in the absence of a fault condition, and the amplifier outputs an induced quadrature signal when a fault condition disconnects one of the skew transducers from the amplifier, and a comparator compares the quadrature output from the pickoff amplifier with a predetermined threshold value and provides a fault indication when the predetermined threshold is exceeded.
    Type: Grant
    Filed: November 27, 2012
    Date of Patent: November 15, 2016
    Assignee: Atlantic Inertial Systems Limited
    Inventors: Michael Durston, Takafumi Moriguchi, Ryuta Araki
  • Patent number: 9476907
    Abstract: An accelerometer comprises a support (12), a proof mass (14) supported for movement relative to the support (12) by a plurality of mounting legs (16), a plurality of fixed capacitor fingers associated with the support (12) and a plurality of movable capacitor fingers associated with the proof mass (14), the fixed capacitor fingers being interdigitated with the movable capacitor fingers, the mounting legs (16) being of serpentine shape, each mounting leg (16) comprising at least a first generally straight section (16a), a second generally straight section (16a), and an end section (16b) of generally U-shaped form interconnecting the first and second generally straight sections (16a), wherein the thickness Te of the end section (16b) is greater than the thickness Tc of a central part (16c) of both of the first and second generally straight sections (16a).
    Type: Grant
    Filed: October 2, 2012
    Date of Patent: October 25, 2016
    Assignee: Atlantic Inertial Systems Limited
    Inventors: Alan Malvern, Louise Snell, Steven Westbury
  • Patent number: 9470530
    Abstract: An electronic device comprises a circuit substrate (5), and a moulded interconnect device (4) incorporating integral legs (8) to mount the interconnect device upon the substrate, the legs spacing at least one of the legs carrying a conducting track (20, 21, 22) to provide an electrical interconnection between the interconnect device and the substrate. The substrate (5) may comprise another moulded interconnect device and may be mounted upon a processor (3) and may include an electromagnetic shield (30) on its lower surface.
    Type: Grant
    Filed: November 29, 2012
    Date of Patent: October 18, 2016
    Assignee: ATLANTIC INERTIAL SYSTEMS LIMITED
    Inventor: Henry Thomas
  • Patent number: 9395187
    Abstract: A device is described herein for determining azimuth comprising a MEMS inertial measurement unit (IMU), a GPS system comprising a GPS antenna and receiver, and a processor configured to receive data from said IMU and from said GPS system, said processor being configured to process said IMU data and said GPS data to derive a true north reference based on said IMU data and said GPS data. A method for determining azimuth is also described herein.
    Type: Grant
    Filed: July 10, 2014
    Date of Patent: July 19, 2016
    Assignee: ATLANTIC INERTIAL SYSTEMS LIMITED
    Inventors: John Keith Sheard, Nicholas Faulkner
  • Patent number: 9374069
    Abstract: A method of processing an amplitude-modulated analog signal at a carrier frequency Fc comprises: digitizing the analog signal to produce an input bit stream that represents the amplitude of the analog signal; generating an in-phase reference bit stream that is synchronous to the carrier frequency Fc and represents an in-phase digital reference signal substantially in the form of a sine and/or cosine wave; and multiplying the input bit stream with the in-phase reference bit stream to produce an output bit stream representing the amplitude modulation of the analog signal.
    Type: Grant
    Filed: July 25, 2014
    Date of Patent: June 21, 2016
    Assignee: Atlantic Inertial Systems Limited
    Inventor: Kevin Townsend
  • Patent number: 9310201
    Abstract: A silicon MEMS gyroscope is described having a ring or hoop-shaped resonator. The resonator is formed by a Deep Reactive Ion Fitch technique and is formed with slots extending around the circumference of the resonator on either side of the neutral axis of the resonator. The slots improve the Quality Factor Q of the gyroscope without affecting the resonant frequency of the resonator.
    Type: Grant
    Filed: September 5, 2011
    Date of Patent: April 12, 2016
    Assignee: ATLANTIC INERTIAL SYSTEMS LIMITED
    Inventor: Christopher Paul Fell