Alan Feinstein, Nanomotion Ltd. Confidential Page 1 Introduction - PowerPoint PPT Presentation

Performance and Applications of L1B2 Ultrasonic Motors Alan Feinstein, Nanomotion Ltd. Confidential Page 1

Introduction  Compact ultrasonic motors – Principle of operation: transferring electrical energy into mechanical momentum by frictionally coupling a vibrating elastic stator to a moving stage  Technology Advantages – High power density – Unlimited travel – Direct drive – Compact dimensions – High resolution – High dynamic range – Fast response time – Superior ―move and settle‖ performance – Built in brake – Built in ―clutch‖ – No intrinsic magnetic field / No EMI – UHV Compatible Confidential Page 2

The Piezoelectric Effect  Direct Effect:  Reverse Effect: – Converts mechanical strain into – Converts electrical fields into electric charge crystal deformation – This effect is used in – An effect used for generating microphones, accelerometers, vibrations and motion in gas lighters etc. actuators, transducers etc. F F Confidential Page 3

L1B2 Ultrasonic Motor – Basic Principles Quadratic electrode design  producing L1&B2 vibration Stiff bearing for backing the ceramic modes by diagonal excitation strip Hard ceramic tip and strip enable Side spring friction with side force bearing transfer mechanism for backlash free motion Bending Mode Longitudinal Mode Back spring maintain constant tip contact force Confidential Page 4

Architecture of a Precision Motion Solution Closed loop motion control  – Ultrasonic motor coupled to a motion axis – Motor driver – Motion controller – Position feedback (position encoder) Confidential Page 5

Basic Driver Design Translates controller command to motor voltage  Motor Velocity to Controller Command relationships :  – With dead zone – Without dead zone – Actuator mode, for increased accuracy near the target area Nanomotion AB1A driver*, HR type motor Nanomotion AB5 driver*, HR type motor * Nanomotion Ltd. User Manual HR Motors. Available online: http://www.nanomotion.com/wp-content/ uploads/2015/09/HR00458000-00-HR-Motor-User-Manual.pdf. Confidential Page 6

Basic Driver Design  Coupling between the mechanical resonance of a vibrating piezo- ceramic and the electrical resonance of an AC driving circuit – Relatively high vibration amplitude – Low DC supply voltages – High efficiency in (low) DC to (high) AC voltage conversion • Small driver can power a large number of motors in parallel Nanomotion AB1A driver* architecture Diagram of the output stage with an internal LC card (single channel with a direction switch) *AB1A Driver . Available online: http://www.nanomotion.com/wp-content/uploads/2015/01/AB1A458000-00-User-Manual-AB1A1.pdf . Confidential Page 7

Open Loop Motion Generation  Force-Velocity Performance determined by: – Amplitude and Frequency of tip motion • Element Geometry • d 31 piezoelectric coefficient • Amplitude of the applied electric field • Quality of the mechanical and electrical resonances – Friction Forces: element Preload force and Friction Coefficient • Correct choice of the friction couple materials Nanomotion HR2 motor Nanomotion AB1A driver Linear motion axis (mass 235 gram)  Velocity Profile ∙ 1 − 𝑓 − 𝑢 𝑛𝑊 𝐷 𝑛𝑏𝑦 – 𝑊 𝑢 = 𝑊 𝜐 , 𝜐 = 𝑛𝑏𝑦 𝐺 𝑛𝑏𝑦 – 𝐺 𝑛𝑏𝑦 = Maximal Force – 𝑊 𝑛𝑏𝑦 = Maximal Velocity – 𝑛 = moving mass 𝐷 – 𝑊 = Max. Vel. at a given command level 𝑛𝑏𝑦 Confidential Page 8

Closed Loop Control Scheme Closed Loop Control  – High bandwidth PIV controller with a non-linear mechanism – Servo loop special position control elements • Offset mechanism — provides an initial command starting value to overcome the inherent dead zone • Zero Feed Forward mechanism — improves the stage settling time • Dead Zone mechanism — takes advantage of the motor intrinsic friction to prevent jitter and improve settling time Motion controller servo loop block diagram Nanomotion XCD controller* * Nanomotion Ltd. XCD Software Version 1.4.0.7. Available online: http://www.nanomotion.com/wp- content/uploads/2014/05/XCD-software-version-1-4-0-7.pdf. Confidential Page 9

Operational Conditions  Proper choice of materials allows smooth motor operation – In a high vacuum (e.g. Nanomotion high vacuum motors) – In a clean room (e.g. Nanomotion motors for semiconductor metrology) – Wide Temperature range • NM standard HR motors: from 0 ° to +50 ° C • NM Edge motors: from -55 ° to +80 ° C Confidential Page 10

Example: Positioning Accuracy NM HR8-V motor, linear stage with a 0.5 kg  mass (FB75-100-HR8 stage) – 10 mm movements back and forth – Settling time < 100 ms – Settling window <50 nm Confidential Page 11

Example: Positioning Accuracy w/DC mode NM HR8-V motor, linear stage with a 0.5 kg mass  4 nm step Peled, G.; Yasinov, R.; Karasikov, N. Performance and Applications of L1B2 Ultrasonic Motors. Actuators 2016 , 5 , 15. Confidential Page 12

Example: High Accuracy Metrology Stage  28 kg inspection stage, NM HR motors, DC mode active – 1 mm steps, at 3 mm/s, 100 mm/s^2 – Convergence target radius: 10 nm – Position error after each step < 2 nm – Drift Specification: less than 2 nm in 2.5 hours Position Error after each 1mm step Position Drift 3 hours after the end of motion Confidential Page 13

Example: High Accuracy Metrology Stage  28 kg inspection stage, NM HR motors, DC mode active 1 mm steps, at 3 mm/s, 100 mm/s^2  Position error after each step < 2 nm  Example Convergence to less than 30 nm in 100 ms, to less than 2 nm in 200 ms Confidential Page 14

Example: Positioning Accuracy – Rotary stage Nanomotion FBR60, powered by two NM HR2 vacuum motors  Consecutive 90 ° moves  Position error is measured 10 seconds after the end of motion  Peled, G.; Yasinov, R.; Karasikov, N. Performance and Applications of L1B2 Ultrasonic Motors. Actuators 2016 , 5 , 15. Confidential Page 15

Example Applications – Vacuum/Space NM HR2 vacuum motor  230 gram linear vacuum stage  Operating in high vacuum (1E-6 Torr)  – Back and forth 1.8 mm steps – 90 million cycles – 40 mm/s velocity – Average rms position error below 3 um Motion Profile Confidential Page 16

Example Applications – Semiconductor Metrology  Example Semiconductor and Metrology stages Confidential Page 17

Example Applications – Optics/Optronics  NM Edge type motor – Max. vel. > 200 mm/s, a – Max. (stall) force > 0.35 N – Motor Stiffness > 0.06 N/µm  Example NUC shutter stage – 15 grams – Aperture area: 14.7 × 17.0 mm – Open/Close time: 150 ms Confidential Page 18

Markets Served Markets Defense Semiconductors Medical Custom solutions Building blocks components Confidential Page 19

Standard components Confidential Page 20

Building Blocks – Subsystems- Solutions Confidential Page 21