摘要:
One embodiment of the invention includes a CVG system. A plurality of electrodes electrostatically force a resonator into a periodic motion based on a drive axis forcer signal applied to a first set of the plurality of electrodes and a sense axis force-rebalance signal applied to a second set of the plurality of electrodes, and provides a sense axis pickoff signal and a drive axis pickoff signal. A gyroscope controller generates the drive axis forcer signal based on the drive axis pickoff signal and calculates an angular rate of rotation about an input axis based on the sense axis force-rebalance signal. The gyroscope controller modulates a predetermined disturbance signal component onto the sense axis force-rebalance signal and to control a modulation phase of the sense axis force-rebalance signal based on detection of the predetermined disturbance signal component in the sense axis force-rebalance signal to substantially mitigate bias and scale-factor error.
摘要:
One embodiment of the invention includes a CVG system. A plurality of electrodes electrostatically force a resonator into a periodic motion based on a drive axis forcer signal applied to a first set of the plurality of electrodes and a sense axis force-rebalance signal applied to a second set of the plurality of electrodes, and provides a sense axis pickoff signal and a drive axis pickoff signal. A gyroscope controller generates the drive axis forcer signal based on the drive axis pickoff signal and calculates an angular rate of rotation about an input axis based on the sense axis force-rebalance signal. The gyroscope controller modulates a predetermined disturbance signal component onto the sense axis force-rebalance signal and to control a modulation phase of the sense axis force-rebalance signal based on detection of the predetermined disturbance signal component in the sense axis force-rebalance signal to substantially mitigate bias and scale-factor error.
摘要:
One embodiment of the invention includes an inertial system. The system includes at least one inertial sensor configured to measure an inertial parameter associated with each of at least one axis. The system also includes a calibration system configured to sequentially measure an inertial calibration parameter at each of a plurality input axes. The system further includes an inertial processor configured to calculate motion of the inertial system based on the inertial parameter associated with each of the respective at least one axis and the sequential measurements of the inertial calibration parameter at each of the plurality of input axes.
摘要:
One embodiment of the invention includes an inertial system. The system includes at least one inertial sensor configured to measure an inertial parameter associated with each of at least one axis. The system also includes a calibration system configured to sequentially measure an inertial calibration parameter at each of a plurality input axes. The system further includes an inertial processor configured to calculate motion of the inertial system based on the inertial parameter associated with each of the respective at least one axis and the sequential measurements of the inertial calibration parameter at each of the plurality of input axes.
摘要:
Dielectric waveguide-to-transmission line transition structures are disclosed which can be used to interface low loss dielectric waveguides with integrated electric circuits for operation in millimeter wave frequency ranges on the order of 100 GHz. Numerous transition designs are presented for interfacing signal propagation in rectangular or cylindrical coplanar metallic transmission lines to signal propagation in dielectric waveguides. In one embodiment of the present invention, a transition structure is provided which includes a first transition section for interfacing a dielectric waveguide to a microstrip transmission line, and a second transition section for interfacing the microstrip transmission line to a coplanar transmission line. In other embodiments of the present invention, the dielectric waveguide interfaces directly to a coplanar transmission line. One embodiment employs a "T" junction for splitting a vertically polarized incoming signal in a dielectric waveguide into two horizontally polarized signals for propagation along a coplanar transmission line. Power splitter and polarization rotation structures are also provided in which either signals from a pair of dielectric waveguides can be combined in a single coplanar transmission line or the polarization of a signal can be changed prior to entering a transition structure.
摘要:
This invention relates to ultra-thin semiconductor films which can be in the submicron range formed from semiconductor materials such as silicon, germanium and gallium arsenide. The films are formed by creating a thin slightly damaged surface on the polished reverse side of a film (e.g., a wafer) of the semiconductor by low dose ion implantation and then etching the semiconductor material on the front side of the film to remove the semiconductor material down to the ion implanted damaged layer. While the implanted ions can be chosen from functionally desirable ions which upon annealing remain in the film to alter the original electrical characteristics, the implanted ions can also be chosen so that upon annealing, the resultant ultra-thin semiconductor film has the same electrical characteristics as the original semiconductor material.The ion implantation changes the etching characteristics of the ion implanted layer. Thus, when the partially damaged semiconductor material is exposed to an etchant the etching rate in the damaged region is decreased by a factor of several thousand as compared to the undamaged semiconductor material.
摘要:
A field-effect transistor (FET) and a corresponding method for its fabrication, the transistor having a source and a gate located at opposite faces of an active channel region formed in a substrate, the source being substantially shorter in effective length than the gate and located symmetrically with respect to the gate. The transistor also has two drains, located one at each end of the channel region, and charge carriers flow from the source to the drains in two paths, under control of the same gate. Electrical contact with the source is made from beneath the substrate, while contact with the gate and drains is made from above. The resulting device has a large incremental transconductance and relatively small parasitic impedances, and therefore can operate at much higher frequencies than conventional FET's.
摘要:
A silt fence is provided which includes an elongated first strip of material which was a relatively uniform porosity and which is fabricated from filaments of relatively small diameter. The first strip is attached to an elongated second strip of material which is fabricated from yarns in a grid pattern, the yarns being of relatively large diameter relative to the filaments of the first strip of material and having from about 2 to 8 yarns per inch in each direction. The composite strip has a Frazier air permeability of from about 100 to 1000 cubic feet per square foot per minute at 1/2 inch of water pressure. The material may be provided with a hem in which is disposed a tensioning member.In use the tensioning member in the hem is attached to posts and the other edge of the material is buried in a trench in the ground.
摘要:
An exemplary inertial measurement apparatus has first and second inertial instruments that are oriented to have parallel sense axes and that produce respective first and second sensed output signals representative of an inertial attribute to be measured. Respective first and second scale factors are used in producing the first and second sensed output signals. Bias errors in the first and second instruments are estimated using the change in state of sign of the first and second scale factors during the first and succeeding time intervals. To facilitate measurement of bias errors in the first and second instruments, a substitute scale factor is determined to be an equivalent of the second scale factor and is based on the first scale factor and a difference between the first and second scale factors. Errors in the second scale factor are calculated based on the first scale factor and the substitute scale factor during first and succeeding time intervals where a sign of one of first and second scale factors changes from one state during the first time interval to the other state during the succeeding time intervals. First and second corrected output signals are generated based on the respective first and second sensed output signals and correction of said second scale factor error.
摘要:
A dithered Coriolis acceleration sensor system has a proof mass that is free of feedback in the accelerometer servo loop at the dither frequency by totally notching out all feedback torque at this frequency. The proof mass relative motion is then a direct measure of the rate because there is no feedback torque to alter the proof mass response to the acceleration. The feedback modulation system according to the invention captures the Coriolis-sensor output such that the phase and gain of the signal generated from the sensor are of no concern in maintaining good scale factor.