AMG LP Gimbal

Description

Design Features

  • Continuous 360 degree rotation of azimuth and elevation including built-in slip ring
  • High accuracy angular position and rate capability
  • Direct-drive brushless servomotors result in zero backlash
  • Cog-free design for outstanding velocity stability
  • Accommodate loads up to 200 mm in diameter
  • Low maintenance and high reliability provide the lowest cost of ownership

Aerotech's new AMG LP (Low Profile) position and rate gimbal mounts provide ultra-precise angular position, rate, and acceleration for development and production testing of a wide range of systems. The AMG LP series is ideal for directing optics, lasers, antennas, and sensors at high speed to precise pointing angles. Typical applications include missile seeker test and calibration, electro-optical sensor and FLIR testing, optical testing of sensors in a vacuum, and angular testing of inertial sensors such as gyros, MEMS, and accelerometers. The AMG LP gimbal design incorporates recent Aerotech rotary stage design improvements to provide high performance at an affordable price. The finest quality motors, bearings, and encoders are integrated into precision-machined housings to ensure peak performance. The AMG position and rate gimbals provide precise angular motion with the high performance customers expect from Aerotech products.

Low Profile

By incorporating our low-profile direct-drive rotary stages, the LP series is capable of speeds and accelerations that are significantly higher than other competing products of this size. These gimbals have a lower profile compared to competing products within given torque ranges. This results in a smaller and more effective gimbal for many applications where beam height and chamber volume are of utmost concern. Customers with only limited azimuth travel requirements can have the slip-ring removed for an even lower overall height. Keeping the optical path lower helps improve overall test accuracy. Based on the ADRS rotary stage, the AMG LP provides a high accuracy, smooth motion solution with low maintenance and high reliability.

Accurate 360° Positioning and Rate Generation

Direct-drive brushless torque motors, with rare-earth magnets and high-accuracy angular transducers are coupled directly to precision shafts for accurate and smooth 360° continuous motion. The absence of gear trains and other drive mechanisms eliminates position error contributions due to mechanical hysteresis and backlash. Directly-coupled high-resolution position transducers ensure highly accurate and repeatable positioning.

A wide range of performance feedback grades is available. Typical line gimbal resolution ranges from 0.87 to 0.32 µrad with Aerotech controls. A built-in azimuth slip ring provides for continuous rotation with no cable wrap-up.

Superior Mechanical Design Features

High quality, low-profile bearings maximize performance with respect to wobble, moment stiffness, and rotating friction. Travel limits, hardstops, and brakes are available as standard options.

Mirror and Alternate Payload Accommodation

A variety of mirror cell diameters are available for standard optic applications. We also provide for custom payload attachment solutions for various device interfaces. Each gimbal mirror cell can be modified or replaced with different shaped cells to accommodate sensors or other odd shaped payloads. We understand customer payloads vary and our engineers have a variety of solutions to implement payloads with offset CGs.

Direct-Drive Motors for Outstanding Control

To maximize positioning and velocity performance, AMG LP gimbal mounts utilize Aerotech’s high torque S-series brushless, slotless servomotors. These motors have all of the advantages of a brushless direct-drive motor — no brushes to wear, no gear trains to maintain, high acceleration, and high speeds. Since it is a slotless, ironless design, there is zero cogging, meaning there is absolutely no torque ripple. This results in smoother motion throughout travel and more precise positioning. These motors are available in different winding configurations to work with high- or low-voltage power supplies.

Specifications

AMG LP Specifications

ModelAMG-100LPAMG-150LPAMG-200LP
Travel 360° Continuous, AZ/EL
Maximum Bus Voltage 340 VDC
Maximum Torque (Continuous) Azimuth 2.36 N·m 2.36 N·m 5.99 N·m
Elevation 0.48 N·m 0.48 N·m

2.36 N·m

Clear Aperture Diameter 95 mm 144.3 mm 193.8 mm
Accuracy(1) ±24 µrad to ±192 µrad (±5 to ±40 arc sec)
AZ Repeatability(2) 19.4 µrad (4 arc sec)
EL Repeatability(2) 14.5 µrad (3 arc sec) 19.4 µrad (4 arc sec)
Maximum Rotary Speed(3) 100 rpm
Maximum Load Capability 6.8 kg 16 kg
Axis Wobble 97 µrad (20 arc sec)
Orthogonality 72 µrad (15 arc sec)
Standard Finish Black Anodize with Hard-Coated Cell
Max Component Diameter 103 mm 153.7 mm 205 mm
Nominal Component Thickness 19 mm 30 mm 40.9 mm
Mass (Without Mirror) 9.5 kg 11.1 kg 21.5 kg
Inertia AZ(4) 0.038 kg-m2 0.071 kg-m2 0.24 kg-m2
Inertia EL(4) 0.001 kg-m2 0.0038 kg-m2 0.012 kg-m2
AZ Aperture When Slip Ring Is Removed (AZ Travel Must Be Limited) 15 mm 15 mm 25 mm
Aperture With Slip Ring No Aperture
Height to Mirror Centerline 181 mm 220 mm 254 mm
Height to Mirror Centerline Without Slip Ring (Limited Travel)(5) 140.5 mm 179.5 mm 213.5 mm
  1. ±24 µrad calibrated (HALAR); ±192 µrad uncalibrated.
  2. Repeatability and accuracy are dependent on encoder resolution. To achieve the listed specifications, encoder resolution must be 0.36 arc sec or less.
  3. Maximum speed based on stage capability; maximum application velocity may be limited by system data rate and system resolution.
  4. Unloaded inertia.
  5. Bottom wiring cover is 40.5 mm tall. If customer is using a limited travel system without optical limits then this height can be removed from height with slip ring.

Dimensions

  • AMG-100LP
  • AMG-150LP
  • AMG-200LP

Ordering Information

Ordering Example

AMG -150LP -AS (Opt.)/

Ordering Options

ModelCell Size Position Transducer Stage & Assembly Options
AMG -100LP
-150LP
-200LP
-AS
-X5
-X10
-X25
-X50
/VAC3
/VAC6

AMG LP Direct-Drive Motorized Gimbal

Option Description
AMG-100LP 103 mm cell ID; mirror CG is at the center of rotation; mirror face offset forward of the rotation intersection of AZ/EL 8.5 mm
AMG-150LP 154 mm cell ID; mirror CG is at the center of rotation; mirror face offset forward of the rotation intersection of AZ/EL 12.7 mm
AMG-200LP 205 mm cell ID; mirror CG is at the center of rotation; mirror face offset forward of the rotation intersection of AZ/EL 16.9 mm

AMG-100LP/150LP Position Transducer

Option Description
-AS Standard feedback device; 1 Vpp sine wave output; 10,000 cycles per rev on AZ, 3600 cycles per rev on EL
-X5 Square wave digital output; 6.48 arc sec resolution on AZ; 18 ar -sec resolution on EL
-X10 Square wave digital output; 3.24 arc sec resolution on AZ; 9 arc sec resolution on EL
-X25 Square wave digital output; 1.30 arc sec resolution on AZ; 3.6 arc sec resolution on EL
-X50 Square wave digital output; 0.65 arc sec resolution on AZ; 1.8 arc sec resolution on EL

Note: Digital output encoder signals are synthesized with a 16 MHz clock. Care must be taken to ensure that the encoder sample rate on the controller is at least 16 MHz or higher. Slower clock rates are available on request.

AMG-200LP Position Transducer

Option Description
-AS Standard feedback device; 1 Vpp sine wave output; 10,000 cycles per rev on AZ and EL
-X5 Square wave digital output; 6.48 arc sec resolution on AZ/EL
-X10 Square wave digital output; 3.24 arc sec resolution on AZ/EL
-X25 Square wave digital output; 1.30 arc sec resolution on AZ/EL
-X50 Square wave digital output; 0.65 arc sec resolution on AZ/EL

Note: Digital output encoder signals are synthesized with a 16 MHz clock. Care must be taken to ensure that the encoder sample rate on the controller is at least 16 MHz or higher. Slower clock rates are available on request.

Stage Construction Options

Option Description
/VAC3 Vacuum preparation of stage to 10-3 torr
/VAC6 Vacuum preparation of stage to 10-6 torr

AMG-100LP Accessories

Option Description
AOM4T3 3-inch mirror cell adapter