Michael Perlmutter

High-performance, low cost inertial MEMS: A market in motion!

The latest advances in MEMS inertial sensors for applications where size, weight, power, and cost are key considerations are having profound effects on the market place. MEMS industrial and tactical-grade sensors are the most dynamic technology in the high-performance inertial industry. Vole Development sees the market growing from

A tactical fiber optic gyro with all-digital signal processing

381.8M in 2011 to

Tactical fiber optic gyro with all-digital signal processing

638.8M in 2017 for single MEMS accelerometers and gyroscopes or assemblies of MEMS accelerometers and gyroscopes. However many technical and commercial challenges are predicted for the manufacturers involved in MEMS: how to guarantee a high level of vacuum for keeping high performance over the lifetime, how to bring down the costs when most of the applications are in the 100 or 1000 unit range per year and what are the best business partners to enter new markets which are sometimes captive. Sensitivities of MEMS sensors to vibrations and temperature, that has led to disappointments in recent years because of lower performance and reliability issues. Adoption of MEMS is/was thus slower than expected but the benefits of MEMS are so unique that it is still a strategic technology for most of the largest inertial sensor and system manufacturers. The recent availability of tactical-grade MEMS IMUs is clearly attractive for a wide range of applications. Indeed many applications will find interest in low-cost devices while it also opens new market opportunities such as precision guided munitions or small size UAVs. This explains why nearly every major IMU manufacturer has access to MEMS technology today. The presentation will start with a focus on the MEMS accelerometer market: current technical trends will be described (development of close-loop high-g accelerometers) and an overview of the most important applications will be given. This will be followed by an overview of MEMS gyroscopes to be described in the second part of the presentation. Finally, a ranking of the most important MEMS suppliers will be presented and the impact of MEMS developments on the traditional value chain will be discussed.

Three-axis nested fiber optic gyroscope

Northrops Electronics Systems Division has built and tested a tactical fiber optic gyro (FOG) with all-digital signal processing. The Northrop FOG uses 160 meters of polarization maintaining optical fiber wound on a spool 29 mm in diameter. Without any data compensation, this FOG has demonstrated excellent scale factor stability and non-linearity (<100 ppm) over a high dynamic range (/spl plusmn/1400/spl degs), low random walk (<0.02/spl deg/spl radic/h), and outstanding bias stability over temperature and day-to-day (<1/spl degh). An inertial measurement unit (IMU) utilizing a FOG/MSA (micro silicon accelerometer) cluster has been developed and integrated with a Global Positioning System (GPS) receiver. Testing was done to demonstrate performance of the sensor and IMU over the military environment.<<ETX>>

Remote fiber optic gyroscopes for a broad range of applications

Northrops Electronics System Division has built and tested a tactical fiber optic gyro (FOG) with all-digital signal processing. The Northrop FOG uses 160 meters of polarization maintaining optical fiber wound on a spool 29 mm in diameter. Without any data compensation, this FOG has demonstrated excellent scale factor stability and non-linearity (< 100 ppm) over a high dynamic range (+/- 1400 degree(s)/s), low random walk (< 0.02 degree(s)/(root)hr), and outstanding bias stability over temperature and day-to-day (< 1 degree(s)/hr). An inertial measurement unit (IMU) utilizing a FOG/MSA (Micro Silicon Accelerometer) cluster has been developed and integrated with a GPS receiver. Testing was done to demonstrate performance of the sensor and IMU over the military environment.

Selecting The Optimum Inertial Sensor For Each Specific Application - A Comprehensive Guide Based on Analytic Criteria and Experimental Data Across Several Sensors and Technologies

This paper provides a description of the three-axis nested fiber optic gyroscope (FOG). The three-axis FOG is being developed by System Engineering Solutions, Inc. (SES) and its prime subcontractor Fibersense Technology Corp. (FTC) under sponsorship by the Aviation Applied Technology Directorate of the US Army Aviation and Missile Command, a Phase II SBIR. The three-axis FOG being developed by SES is based on the design of a nested configuration of three free-standing elliptical fiber optic coils (patent pending), in a supporting assembly that yields substantial size and weight advantages. It permits use of a single environmental shield and thermal isolation enclosure. The nested assembly of three free-standing coils in its supporting structure with electro-optical components weighs less than 0.4 pounds and its volume is 19 cubic inches, not including shielding and isolation enclosure features which are application and interface dependent. Performance goals for the army three-axis gyroscope are discussed.

Ring laser gyro and magnetic mirror therefor

Fibersense Technology Corporation has completed the development of a new type of Fiber Optic Gyroscope (FOG) configuration in which the sensing element-the fiber coil-is separated from all other gyro elements. This configuration allows fiber coils to be located on the device of interest, without requiring any electrical connections to the rest of the gyro or system. A production version of this configuration, now being manufactured for a missile application, uses a sensing coil 1.3 inches in diameter and 0.3 inches thick. Without data compensation this FOG is capable of a dynamic range in excess of 10,000/spl deg//sec, an angle random walk of less than 0.03/spl deg///spl radic/h, and a bias stability over temperature and day-to-day of less than 2/spl deg//h. This FOG requires only /spl plusmn/5 volts to operate its low cost, all-digital signal processing electronics which produce a digital output proportional to rotation rate. Variations of this configuration, capable of 0.01/spl deg//h bias stability, have also been developed and demonstrated.

Environmental characteristic determination

It is a very difficult task to select the proper sensor performances for each applications in order to meet cost-effectiveness criteria. The purpose of this paper is to provide a comprehensive guide based on analytic criteria such as Allan variance analysis in order to highlight what are the performance requirements for several kind of inertial sensors based applications. Several types of sensor (gyroscopes and accelerometers) technologies (MEMS, FOG, CVG, QUARTZ) have been evaluated from different vendors. A comparative analysis of the meaningful parameters such as ARW, bias stability, etc. was performed, providing guidelines on how such sensor parameters relate to the various application performance requirements.