{"title":"A new Silicon axisymmetric Gyroscope for Aerospace Applications","authors":"N. Vercier, B. Chaumet, B. Leverrier, S. Bouyat","doi":"10.1109/ISS50053.2020.9244886","DOIUrl":"https://doi.org/10.1109/ISS50053.2020.9244886","url":null,"abstract":"For several years Thales has been developing silicon micro-machined tuning fork gyroscopes for military and civil applications, notably for the aerospace segment. Benefitting from this know-how, a brand new gyroscope based on an axisymmetric structure has been designed over the last few years.The technology is based on Deep Reactive Ion Etching (DRIE) on a Silicon On Insulator (SOI) wafer. Associated to an in-plane design, this technology allows the accurate realization of mechanical resonator and trimming elements within a unique active layer. The inherent simplicity of the gyro, composed of two masses vibrating in an anti-phase mode, combined with the defect cancelation capability obtained through electrostatic tuning, lead to a very high level of performance.Electrostatic trimming enables an excellent bias stability to be obtained by cancelling quadrature and frequency mismatch.The signal processing of the gyro is primarily digital and consists of four main closed loops dedicated to control the drive and the sense modes. An auxiliary loop is used for cancelling the quadrature bias and frequency mismatch.The gyro can operate in two modes: whole angle mode (WA) and force-to-rebalance mode (FTR or angle rate mode).The results obtained on a preliminary mock-up in the FTR mode are the following:•random walk =0.006°/√h,•bias instability <0.01°/h•thermal bias instability < 0.1°/h•thermal scale factor instability < 50 ppm•Range: 375°/s (adjustable by the electronics)","PeriodicalId":118518,"journal":{"name":"2020 DGON Inertial Sensors and Systems (ISS)","volume":"1 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2020-09-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"131729996","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"GNSS+inertial+odometer navigation system for land vehicles with an extended odometer’s model identification","authors":"N. Vasilyuk, D. Tokarev","doi":"10.1109/ISS50053.2020.9244893","DOIUrl":"https://doi.org/10.1109/ISS50053.2020.9244893","url":null,"abstract":"An identification of geometric displacements of an odometer is a real-time determination of the odometer’s lever arm vector relative to an IMU, determination of the IMU’s frame attitude relative to a vehicle’s body frame, and a refinement of an odometer’s scale factor. Odometer’s measurements models for steering front wheels and for uncontrolled rear wheels have been developed in detail. Observability conditions of the geometric displacements on trajectories specific for a land vehicle have been considered. It is shown that by setting the odometer’s lever arm components relative to the vehicle body, the observability of all three IMU’s attitude angles on trajectories of a certain shape may be achieved. The partial observability of the geometric displacements in the absence of information about a steering angle of the front wheels has been described. Secondary observable combinations of the geometric displacements have been identified. Odometer’s measurement models have been reformulated in terms of these combinations. An iterative least-squares procedure has been developed for evaluation of these observable combinations in real time. Observation equations have been obtained for incorporating the odometer’s measurements into an observation vector of a navigation loose-coupling Extended Kalman Filter. Experimental results obtained with the odometer, attached on both the front and rear wheels have been presented.","PeriodicalId":118518,"journal":{"name":"2020 DGON Inertial Sensors and Systems (ISS)","volume":"46 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2020-09-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"115940994","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
T. Yang, G. Yang, W. Lu, J. Wang, D. Han, Y. Yin, J. Xu, T. Ren, F. Zhang, P. Liu, X. Jin, Y. Peng
{"title":"A Miniature Quartz Vibrating Beam Accelerometer","authors":"T. Yang, G. Yang, W. Lu, J. Wang, D. Han, Y. Yin, J. Xu, T. Ren, F. Zhang, P. Liu, X. Jin, Y. Peng","doi":"10.1109/ISS50053.2020.9244880","DOIUrl":"https://doi.org/10.1109/ISS50053.2020.9244880","url":null,"abstract":"This paper reports a miniature quartz vibrating beam accelerometer (MQVBA) with the range of 10g, which is expected to be used for inclination and seismic measurements. The design of MQVBA is carefully optimized to focus on the challenge of high accuracy and robustness in harsh environment. The bandwidth of MQVBA can be controlled by adjusting squeeze film air damping in order to meet different needs of inclinometer and seismic ground sensor. Wafer-scale batch MEMS processing and hybrid integration techniques are adopted to fabricate MQVBA. The prototype of MQVBA achieves the bias instability of 0.6μg@41s and the nonlinearity of lower than 0.01% in ±1g input range while showing remarkable endurance in the environment of random vibration up to 2 kHz frequency range.","PeriodicalId":118518,"journal":{"name":"2020 DGON Inertial Sensors and Systems (ISS)","volume":"1 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2020-09-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"115475450","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Effect of Electrostatic Nonlinearity on Force-to-Rebalance Mode of Operation in CVG","authors":"D. Vatanparvar, A. Shkel","doi":"10.1109/ISS50053.2020.9244877","DOIUrl":"https://doi.org/10.1109/ISS50053.2020.9244877","url":null,"abstract":"In Micro Electro-Mechanical (MEM) Coriolis Vibratory Gyroscopes (CVG), the electrostatic frequency tuning mechanism is often used to match the resonant frequencies along the drive and sense axes of the gyroscope. However, the electrostatic frequency tuning results in nonlinearity in the dynamics of the CVG and a large amplitude-frequency coupling is introduced. In this paper, we present a comparative study of the effect of electrostatic nonlinearity on the noise performance of a CVG in the open-loop angular rate mode and the Force-to-Rebalance (FRB) angular rate mode of operation. Based on the experimental noise characterization of a Dual Foucault Pendulum (DFP) gyroscope, it is demonstrated that the amplitude-frequency coupling adversely affects the stability of the resonant frequency along the drive axis of the gyroscope. In the case of the open-loop operation modality, it is shown that noise in the oscillation frequency along with an uncompensated quadrature coupling between the sense and drive modes causes noise degradation and scale-factor instability. In the FRB mode, however, by using Quadrature Nulling Control (QNC) and Rate Control (RC) loops, the zero-rate output and scale-factor were observed to have much lower sensitivity to frequency instability along the drive axis, caused by the amplitude-frequency coupling. In the case of the DFP gyroscope, we demonstrated that the FRB mode provides a 20-times lower Angle Random Walk (ARW), as compared to the open-loop mode of operation. In this work, by operating the DFP gyroscope in the FRB mode, an ARW better than 0.0068 deg/√hr and a Bias Instability (BI) better than 0.09 deg/hr were demonstrated at a vibration amplitude of 0.8 microns, equivalent to half of the capacitive gap size.","PeriodicalId":118518,"journal":{"name":"2020 DGON Inertial Sensors and Systems (ISS)","volume":"64 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2020-09-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"134138792","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Evolution and Capitalisation of a Family of MEMS Vibrating Structure Gyros (VSG)","authors":"A. Kelly, S. Parrish, C. Fell","doi":"10.1109/ISS50053.2020.9244905","DOIUrl":"https://doi.org/10.1109/ISS50053.2020.9244905","url":null,"abstract":"The origins of the Silicon Sensing Systems Ltd (SSSL) and Atlantic Inertial Systems (AIS) - a Collins Aerospace company, MEMS Coriolis Vibratory Gyro (CVG) technology can be traced back to the early 1990’s. The fundamental principles of operation have remained broadly unchanged and have been successfully applied to a wide and growing range of applications.SSSL together with its joint venture parent companies AIS and Sumitomo Precision Products of Japan (SPP), have continued to invest in applied research and in the practical integration of the MEMS Coriolis gyros year on year, generating a myriad of award winning innovations.These gyros have not only facilitated the development of a substantial range of industry leading IMU’s and DMU’s (Dynamic Measurement Units) for AIS and SSSL respectively, but have also been used as standalone sensors by a global user base, being widely integrated in to AHRS and other inertial reference systems.These innovations cover the full spectrum of signal processing architectures, sensors materials, MEMS design, MEMS processes, packaging, electronics, software, algorithms, manufacturing and calibration.This sustained focus, lessons learned and grounded heritage has produced a family of CVGs that is continually evolving and being proven in commercial and defense applications. Some of these innovations were first presented at DGON ISS in a 1997 paper [1] with additional presentations at subsequent conferences [2–4].In this paper we present a consolidated history of that heritage and the evolution of the SSSL inductive CVG design describing the technical innovations that have been applied. Some examples of the performance capability and range of applications are also provided. Whilst not without its challenges, this sets SSSL and AIS firmly on course to develop inertial systems that are, proven by data, to be beyond tactical grade.","PeriodicalId":118518,"journal":{"name":"2020 DGON Inertial Sensors and Systems (ISS)","volume":"1 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2020-09-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"129387431","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}