摘要:
A vibration damper assembly for a ring resonator of a vibrating structure gyroscope has a female portion attachable to a body of the gyroscope so as to have limited resiliency with respect to the body in a direction substantially perpendicular to the body. A male portion is fixedly attachable at one end to a resonator of the gyroscope, projectable into the female portion and fixedly attachable at its other end in and to the female portion. The assembly permits damping of vibratory movement of the resonator in a direction substantially perpendicular thereto whilst retaining stiffness and freedom to vibrate for the resonator in the plane thereof.
摘要:
A vibrating structure gyroscope has a vibratory resonator having a substantially ring or hoop-like shape structure, an electromagnetic drive for causing the resonator to vibrate, a support structure including a plurality of flexible support beams for supporting the resonator whilst allowing it to vibrate and an electromagnetic sensor for sensing movement of the resonator. The support beams and resonator are made from silicon and the electromagnetic drive and sensor include metal tracks which extend externally along each support beam onto and along respective segments of an outer substantially planar surface of the ring-like resonator. The resonator is substantially planar and means is produced a magnetic field substantially perpendicular to the plane of the resonator.
摘要:
Bias error is reduced in a vibrating structure sensor having primary and secondary pick-offs separated by a fixed angular amount (45°) with respect to the vibrating structure by summing a proportion of the primary pick-off output signal into the secondary pick-off output signal or subtracting a proportion of the primary pick-off output signal from the secondary pick-off output signal effectively to reduce or increase the angular separation of the secondary pick-off from the primary driver by an amount sufficient to set the rate output signal from the vibrating structure to zero and thereby minimize bias error.
摘要:
An angular velocity sensor is described with improved ageing and hysteresis properties. The sensor may be of a ring type driven by a driver circuit, the sensor further comprising primary and secondary portions having corresponding signal pickoffs. The gain of the primary pickoff signal and the capacitance of the primary portions of the sensor are controlled relative to the gain of the secondary pickoff and the capacitance of the secondary portions of the sensor. Control electronics is provided that enables matching of the relative signals from the respective channels. In this way, temperature hysteresis and ageing effects of materials used in forming the sensor are overcome.
摘要:
An angular velocity sensor is described with improved ageing and hysteresis properties. The sensor may be of a ring type driven by a driver circuit, the sensor further comprising primary and secondary portions having corresponding signal pickoffs. The gain of the primary pickoff signal and the capacitance of the primary portions of the sensor are controlled relative to the gain of the secondary pickoff and the capacitance of the secondary portions of the sensor. Control electronics is provided that enables matching of the relative signals from the respective channels. In this way, temperature hysteresis and ageing effects of materials used in forming the sensor are overcome.
摘要:
An angular velocity sensor or gyroscope has a ring and a primary drive transducer arranged to cause the ring to oscillate in a primary mode substantially at the resonant frequency of the primary mode of the ring. A primary control loop receives primary pick-off signals from the primary pick-off transducer and provides primary drive signals to the primary drive transducer so as to maintain resonant oscillation of the ring. The primary control loop includes a demodulator arranged to determine the amplitude of the fundamental frequency of the primary pick-off signals and a demodulator arranged to determine the amplitude of the second harmonic frequency of the primary pick-off signals and a drive signal generator arranged to produce the primary drive signals 116 with amplitude that is dependent on a ratio of the amplitude of the second harmonic frequency of the primary pick-off signal over the amplitude of the fundamental frequency of the primary pick-off signal as derived by a divider.
摘要:
An angular velocity sensor or gyroscope has a ring and a primary drive transducer arranged to cause the ring to oscillate in a primary mode substantially at the resonant frequency of the primary mode of the ring. A primary control loop receives primary pick-off signals from the primary pick-off transducer and provides primary drive signals to the primary drive transducer so as to maintain resonant oscillation of the ring. The primary control loop includes a demodulator arranged to determine the amplitude of the fundamental frequency of the primary pick-off signals and a demodulator arranged to determine the amplitude of the second harmonic frequency of the primary pick-off signals and a drive signal generator arranged to produce the primary drive signals with an amplitude that is dependent on a ratio of the amplitude of the second harmonic frequency of the primary pick-off signal over the amplitude of the fundamental frequency of the primary pick-off signal as derived by a divider.
摘要:
An inertial sensor is described that has a commanded test function. The sensor is of a ring type driven by a driver circuit, the sensor further includes primary and secondary portions having corresponding signal pickoffs. The primary pickoff signal amplitude is controlled via an automatic gain control, the primary phase lock loop and VCO locks to the resonant frequency to provide the clocks for the synchronous detectors, the primary pickoff signals via the primary phase shift circuit is provided to the primary driver, the secondary pickoff signal being input into a detector circuit capable of detecting motion in the sensor. The commanded test function includes a signal derived from the primary portion of the circuit and input into the two inputs of a differential amplifier in the secondary pickoff detector circuit.
摘要:
A method of making screen printing frames can include, in certain illustrative embodiments, affixing at least two frames to one another, applying a masking film to both frames, exposing the frames, removing the unhardened emulsion in the meshes, and separating the frames from one another for deployment in a screen printing apparatus. This exemplary process can be used to create images in substantially complete registration with one another on frames having different mesh counts. Stated another way, these embodiments permit the use of multiple frames to print different inks through different meshes in a single pass to form images in substantially complete registration with one another. In certain preferred embodiments, a screen printing apparatus can include two frames, each having a mesh with a different pitch, wherein the frames are adapted to receive different inks and held in fixed register during a screen printing operation.
摘要:
A vibrating structure gyroscope comprises a resonant body, a drive transducer for driving resonant motion of the body, a pick-off for producing signals representative of the resonant motion, and a signal processor for extracting z-axis orientation information and x- and y-axis rate information from the signals. The resonant body is planar and the resonant motion takes place in a vibration mode pattern whose orientation angle with respect to the body varies in accordance with z-axis orientation of the body and couples energy into an out-of-plane response mode motion in accordance with rotation of the body about the x- or y-axis. The signal processor resolves the out-of-plane response mode motion with reference to a z-axis orientation signal to extract the x- and y-axis rate information.