Iertial Techology For North Fidig Steve Clarke, Applicatios Egieer. December 2013
To be the leadig provider of affordable, high performace, high itegrity MEMS iertial products ad foudry services 2
Cotets Who we are What a gyroscope does Curret products Typical applicatios MEMS gyroscopes how they work. High precisio gyroscope North fidig Techiques Importat parameters Test Results Summary Questios/Discussio 3
A UTC/SPP Joit Veture Compay UTC Aerospace Systems Sumitomo Precisio Products Silico Sesig Systems Ltd Silico Sesig Products UK Silico Sesig Products Japa Silico Sesig Systems Japa 4
Who we are BAE Systems acquires Codor Pacific & forms Iertial Products (2002) Goodrich acquires AIS (2009) J.F. Lehma acquires Iertial Products & forms Atlatic Iertial Systems (2007) UTC acquires Goodrich ad forms UTC Aerospace Systems (2012) 5
What a gyroscope does Agular rate sesors, are used wheever rate of tur sesig is required without a fixed poit of referece. This separates gyros from ay other meas of measurig rotatio, such as a tachometer. Traditioally, gyros (gyroscopes) were much like the childre s toy a spiig mass supported such that its positio i iertial space remais fixed ad allowig rotatio of its support structure to be measured. The world of iertial sesors has tured o its head with the emergece of solid state o-rotatig rate sesors, still colloquially kow as gyros. Their costructio i silico (or sometimes quartz) explais their other descriptive ame of MEMS (Micro-machied Electro-Mechaical Systems) devices. MEMS gyros emerged through the eed to overcome the biggest problems associated with traditioal spiig wheel gyros mechaical issues such as fragility, reliability, stictio, wear, backlash ad overall life. Based o a vibratig elemet, MEMS gyros sese rotatio rate through a pheomeo kow as coriolis. 6
Curret Product Rage Sigle Axis Gyroscopes PiPoit CRS09/CRS39 CRH01 CRG20 CRS03/CRS07 Combiatio Sesors Orio Accelerometers Gemii Multi-axis DMU02 7
Applicatios Platform Stabilisatio: Camera Stabilisatio Ateas Agriculture Spray Booms Craes Fork Lift Trucks Vehicle Dyamic Measuremets Provig ad Qualificatio Motorsport Black box/accidet recorders Lea Agle Measuremet Ride moitorig Flight Istrumets ad Avioics AHRSs, VRUs, VRSs Autopilots UAVs 8
Applicatios GPS Itegratio ad Augmetatio: Autosteer Precisio Agriculture Auto-helms Tilt Compesatio Precisio Agriculture Navigatio Guidace Navigatio ad Cotrol: Vehicle Navigatio Positio Moitorig Surveyig Vehicle Guidace ad Cotrol Rail: Surveyig ad Track Coditio Moitorig 9
Applicatios Automotive: Black box/accidet recorders Navigatio Techical Toys Model Helicopters Robotics Educatio Kits Iverted Pedulum Plat ad Power Equipmet: Power Tools, safety ad cotrol Law Mowers Domestic/Idustrial Robots Torque Wreches Robotic Vacuum Cleaers 10
A Vibratig Structure Gyroscope, VSG Sesor Head A Gyroscope cosists of a vibratig structure plus cotrollig electroics. 11
Vibratig Structure Gyro (VSG) Techology VSG5 2010 Silico Sesig s gyroscopes are Vibratig Structure Gyroscopes, VSGs These VSGs use shell (cylider or rig) structures ad work o the Coriolis priciple where forces are observed whe a liear motio occurs i a rotatig frame. The closed loop techology provides excellet scale factor ad performace over wide rate ad temperature rages. The techology has a very rugged desig ad costructio ad delivers superior performace tha its competitors usig other structures (e.g. tuig fork). Evolutio ot Revolutio 12
SGH01 Head Deep trech etched i bulk silico Stable ad robust crystallie silico - 100µm thick Plaar costructio Sigle crystal pae Stability of key parameters (f, f1-f2, Q1-Q2) 8 dog Legs to support the vibratig rig. Rig diameter: 6mm Leg width: 60 m Each leg carries three electric tracks 13
How the VSG works c No agular rate applied 14
How the VSG works F c Resultat Radial Motio F c = Coriolis Force Applied Rate F c F c With agular rate applied 15
VSG3 Sesor Head Costructio ca lid upper pole maget silico pedestal glass ca base support glass lower pole 16
Electroic Cotrol Closed Loop Operatio Sesor Head Electroic cotrol loop ad the sesor head eeded to make a gyroscope. Electroic cotrol loop ad the sesor head eeded to make a gyroscope. 17
High Performace MEMS Gyroscopes CRS09 CRS39-01 CRS39-03 CRS09 Rate Rages ± 100º/s ad ± 200º/s Bias Istability ~ 0.6º/h CRS39-01 (upackaged) CRS39-02 (packaged) Rate Rage ± 25º/s Bias Istability ~ 0.3º/h typical CRS39-03 (upackaged) Rate Rage ± 25º/s Bias Istability ~ 0.08º/h typical CRH01 ad CRH02 Rate Rage ± 25º/s ± 100º/s ± 200º/s ad ± 400º/s Bias Istability ~ 0.2º/h (CRH01), ~ 0.1º/h (CRH02) typical CRS39-02 CRH01 CRH02 18
North Fidig Idexig Techique. 0 Measuremet 1 180 CRS39 Sesitive Axis Measuremet 2 270 Table 0 Idexig Table Measuremet 3 90 Measuremet 4 NORTH 19
North Fidig Idexig Techique. 0 Measuremet 1 Headig = ATAN2 ( Meas1 Meas2) ( Meas3 Meas4) 180 Measuremet 2 270 where Meas1 = EarthRate1+FixedErrors1+VariableErrors1 Meas2 = EarthRate2+FixedErrors2+VariableErrors2 Meas3 = EarthRate3+FixedErrors3+VariableErrors3 Meas4 = EarthRate4+FixedErrors4+VariableErrors4 Measuremet 3 but EarthRate2 =-EarthRate1 ad EarthRate4 = -EarthRate3 FixedErrors2=FixedErrors1 ad FixedErrors4=FixedErrors3 therefore ( Meas1 Meas2) = 2xEarthRate1 + ΔVariableErrors12 ( Meas3 Meas4) = 2xEarthRate3 + ΔVariableErrors34 90 Measuremet 4 20
Bias Stadard Deviatio deg/h Bias Istability ad Agle Radom Walk 10000. 0 Alla Variace 1000. 0 100.0 10.0 Gradiet = -1 1.0 Gradiet = -0.5 0.1 0. 001 0. 010 0. 100 1. 000 10. 000 100. 000 1000. 000 Correlatio Time (sec) CRS09 CRG20 PiPoit The stadard deviatio of the bias chages betwee successive averages is plotted agaist the averagig period (or Correlatio Time). Raw oise from the gyroscopes ca be see at the samplig frequecy (there is o averagig here) at the left side of the chart, i.e. at 0.002 secods above. Agle Radom Walk ca be calculated from the poit where the -0.05 Gradiet for a particular plot itercepts the 1 secod poit ad the divided by 60. For the CRS09 above, the gradiet itercepts at 2.8 deg/h, givig a ARW = 0.047 deg/ h. Bias Istability is read from the lowest part of the plots, 0.6 deg/h for CRS09. 21
CRS39: Alla Variace. CRS39-01 CRS39-03 Bias istability improved from 0.3º/h to 0.08º/h Agle Radom Walk improved from 0.013º/ h to 0.0083º/ h 22
North Fidig Accuracy Raw Measuremets Sigle Measuremets Uit 1. Sigle Measuremets Uit 2. 23
North Fidig Accuracy Improvemets Use more tha oe device Use devices to get improvemet factor. Use multiple measuremets Use measuremets to get improvemet factor. Esure the device is warmed up Stable temperature improves bias istability. 24
North Fidig Accuracy Averaged Sigle Measuremets. Averaged Measuremets. 25
North Fidig Accuracy After Warm Up. Averaged Measuremets Uit 1 After Warm Up. Averaged Measuremets Uit 2 After Warm Up. 26
Summary Who we are What a gyroscope does Curret products Typical applicatios MEMS gyroscopes how they work. High precisio gyroscope North fidig Techiques Importat parameters Test Results Summary Questios/Discussio 27
Questios/Discussio Cotact Details: Silico Sesig Systems Ltd., Clittaford Road Plymouth Devo PL6 6DE Tel: +44 (0) 1752 723330 www.silicosesig.com 28
Iertial Techology For North Fidig December 2013