{"title":"Microoptical Gyros Based on Passive Ring Cavities","authors":"Y. Filatov, A. Kukaev, V. Venediktov, E. Shalymov","doi":"10.1109/ISS50053.2020.9244887","DOIUrl":"https://doi.org/10.1109/ISS50053.2020.9244887","url":null,"abstract":"Optical gyros, such as ring laser gyros and fiber optical gyros, have become a mainstay for strapdown inertial navigation systems due to a number of advantages (larger dynamic range of the measured velocities; high stability of scale factor, insensitivity to acceleration and overload; smaller time readiness and etc.). Despite success in their development, ring laser and fiber optic gyros are unsuitable for using in control systems of small portable devices because of their large size and weight. So now the actual task is miniaturization of optical gyros, or development and research of microoptical gyros.During the last decade the main activities in the area of developing the microoptical gyro were concentrated on the scheme of device, based on the use of passive ring single-mode cavities, which are usually produced with the use of planar integral optical technologies.Whispering gallery modes resonators can be also used as the gyro sensitive element instead of planar single-mode resonator. This is due to their following properties: highest optical quality factors, small eigenmodes volume, compactness and relative ease of fabrication. In this work we consider effects arising in the whispering gallery modes resonator during its rotation and possible ways of their application as sensing element of microoptical gyro.","PeriodicalId":118518,"journal":{"name":"2020 DGON Inertial Sensors and Systems (ISS)","volume":"52 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":"132668578","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":"A direct approach for high-quality MEMS based IMU/INS production","authors":"L. Poletti, D. S. Sanchis, R. Siryani","doi":"10.1109/ISS50053.2020.9244876","DOIUrl":"https://doi.org/10.1109/ISS50053.2020.9244876","url":null,"abstract":"This paper describes an industrial process for microelectromechanical systems (MEMS) based inertial measurement unit (IMU) and inertial navigation systems (INS) production. Producing high accuracy sensor in a limited time and with a robust process is a universal problem in IMU and INS production. The challenge we face today is finding a calibration and a performance validation processes which will systematically get the most of each IMU.As MEMS based IMU start competing with other technologies based on high-end gyroscopes, the calibration becomes a critical topic to increase the IMU performance. A common technique used on high-end technologies as Fiber-optic Gyroscopes (FOG) is to combine a set of non-specific multi-position observations and a systematic calibration method as a Kalman filter [1–4]. However, this method requires ultra-low-noise gyroscopes with excellent bias stability and repeatability to correctly measure Earth rotation rate. These attributes are hardly found on MEMS. The method also limits the observability of non-linearities and cross-axis sensitivity errors because of low dynamics.The calibration method proposed here is based on a direct process [5] combined with high dynamics. High dynamics help discarding noise and bias stability from a proper measurement. Also, a direct approach allows to master all the process and gives the possibility to separate and compensate sensors manufacturing and calibration tools imperfections.Finally, the performance assessment and acceptance test presented in this paper are used to check the consistency of the direct approach technique by applying high dynamics after calibration and measuring sensor errors and triads misalignment in a whole temperature range as shown in Figure 1.","PeriodicalId":118518,"journal":{"name":"2020 DGON Inertial Sensors and Systems (ISS)","volume":"50 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":"114700629","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}
D. Marjoux, P. Ullah, N. Frantz-Rodriguez, P-F Morgado-Orsini, M. Soursou, R. Brisson, Y. Lenoir, F. Delhaye
{"title":"Silicon MEMS by Safran - Navigation grade accelerometer ready for mass production","authors":"D. Marjoux, P. Ullah, N. Frantz-Rodriguez, P-F Morgado-Orsini, M. Soursou, R. Brisson, Y. Lenoir, F. Delhaye","doi":"10.1109/ISS50053.2020.9244881","DOIUrl":"https://doi.org/10.1109/ISS50053.2020.9244881","url":null,"abstract":"Safran Electronics & Defense is a world leader in inertial navigation systems for both civilian and military applications. Capitalizing on its industrial heritage, Safran has achieved a major technological breakthrough in the past years by introducing the most CSWAP (Cost Size Weight and Power) navigation-grade INS technology based on HRG CrystalTM gyros.In line with past efforts to push back inertial navigation boundaries, Safran is increasing its technological and competitive edges through the development of new-generation accelerometers.Building on its daughter-company Safran Colibrys expertise and portfolio of tactical grade open loop accelerometers, Safran is indeed a leading player in Silicon MEMS accelerometers. As such, Safran’s choice was naturally steered towards silicon MEMS thanks to their unrivalled CSWAP, characteristics compared to the complex design of legacy pendulous torque-balanced servo-accelerometers.Closed-loop operation technology is indeed essential to reach the most demanding performance levels. For instance, ACSIL accelerometers, with their smart closed-loop operation design, have successfully been used for 30 years in high-grade commercial avionics AHRS.Taking advantage of their combined expertise, Safran Electronics & Defense and Safran Colibrys have brought the performance of closed loop pendulous MEMS accelerometers to an unprecedented level while keeping all the CSWaP benefits of the technology. This accelerometer is currently in production at low rate (LRIP) and is henceforth ready to enter mass-production phase as a component of HRG CrystalTM based INS for all applications including certified aerospace under DO-254 standards.This paper presents the key design choices of our navigation grade Si-MEMS accelerometer: the MEMS sensor architecture and its ∑Δ control electronics including innovative approach to reach very high measurement ranges.Actual product performances statistics from a few hundred-sample production batch are detailed. Navigation grade key characteristics are examined: bias, scale factor, misalignment temperature and ageing stability. Vibration susceptibility, a key performance for harsh environment capability and warm-up response, a key performance required by fast alignment time INS, are also discussed.Designed and matured under a rigorous process, Safran navigation grade MEMS accelerometer has proven a high level of inertial performances and its ability to operate as the ideal accelerometer to be associated to HRG CrystalTM to offer, by far, the best CSWAP INS on the market place.","PeriodicalId":118518,"journal":{"name":"2020 DGON Inertial Sensors and Systems (ISS)","volume":"7 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":"115828890","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}