AO Controls: Status and IssuesAO Controls: Status and Issues

Erik Johansson, Jimmy Johnson,Erik Johansson, Jimmy Johnson,Doug Morrison and Ed WetherellDoug Morrison and Ed Wetherell

NGAO PD Team Meeting #6NGAO PD Team Meeting #6Thursday, March 19, 2009Thursday, March 19, 2009

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Controls• Originally called non-RTC Controls --> renamed for simplicity• Controls encompasses “everything but the kitchen sink”: control of all

devices in the AO and Laser systems– Motion control: control of all movable devices in the system

• All optical stages, shutters, etc.• Does not include position control of deformable or tip-tilt mirrors

– Device control: control of all non-moving devices in the system requiring computer control

• Environmental control– Temperature, humidity, particulates

• Power control• Camera control (setting parameters, not low-level CCD or focal plane control)• DM and TT control

– Any control required not including mirror positioning commands, e.g., control of drive amplifiers, mirror controllers, etc.

• RTC control: set up and operation of the RTC• Laser system control• Data server

– Acquisition, guiding, offloading and pointing control– Instrument control: all coordination and sequencing required to use instrument

with NGAO system– High level coordination and sequencing control of entire NGAO system

3

Major areas of effort

• Overall control system architecture• Software architecture• Sequencer design: Multi-System Command Sequencer (MCS), AO

Sequencer, Laser Sequencer– Sequencers are main command processors and command sequencers

used to control the system

• AO and Laser system SW design (SW not included in sequencers)• Motion control architecture• Motion control design, both HW and SW• Data server design• User interface design• SW standards document

4

Control system architecture

• Control system architecture and SW architecture are deeply intertwined

• Distributed control system organized hierarchically• Independent subsystems, but MCS is master• Instrument does NOT control AO system and telescope

– Instruments in current AO system do this

– Troubleshooting is problematic

– Instrument should be a subsystem of the overall NGAO system

• Each subsystem has levels of control within it

5

Distributed control system

Data ServerAtmospheric

ToolsTelescope Interface

Instruments Laser SystemAO SystemLaser Traffic

Control System

ScienceOperations

ToolsData Communications

Infrastructure

6

Hierarchy of controls

UserInterfaces and

Tools

Data ServerInterface

Atmospheric Tools

Telescope Interface

Instrument Sequencer

LaserSequencer

LaserDevices

AODevices

AOSequencer

LTCS

AO Control Laser Control

Pre- and Post-Observing Tools

Multi-SystemCommandSequencer

Data ServerAcquisition, Guiding and

Pointing Control

CmdStatusTelem

CmdStatusTelem

Real-Time Controller

RT DiagsRT Diags

TelemetryTelemetry

Legend:

Non-Real-Time Commands and Data

Real-Time Commands and Data

Real-Time Diagnostic Data (high-speed)UTT

Status

Top level of control

Middle level of control

Bottom level of control

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Software architecture

• SW architecture “views”– Logical view

• Shows object decomposition

– Development view• SW module organization• Shows interaction of SW components

– Layered view• Shows interaction of SW components in layered hierarchy

– Physical view• Maps SW to HW• Preliminary mapping during PD phase• Full definition during DD phase

– Process view• Shows SW decomposition to tasks, threads, processes• This view will be defined during the DD phase

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Logical view

+Identity()+Middleware Interface()

-ObjectID

BaseObject

+GetConfiguration()

-ConfigurationID

Configurable +GetAlarmStatus()+SetAlarmStatus()+AcknowledgeAlarm()+ResetAlarm()+SetThreashold()+GetThreshold()+RegisterObject()

-HealthTelemetry-HealthID

Health

Controller

+Initialize()+Standby()+Halt()+Fault()+Shutdown()

Sequence Controller

MSCS Sequencer AO Sequencer AGOP Sequencer Laser Sequencer

+Expose()+ExposureRate()+On / Off()+Waveform()+Binning()

-Timing Controller

Camera Controller

+Rate()

-Resolution

Timing Controller

Software Timer Timing Board

+GetCount()+Calibrate()

Sensor Controller

+Temperature()+Humidity()+Fan()

-Partciulate Sensor-Temperature Sensor-Humidity Sensor

EnvironmentController

Temperature SensorHumidity Sensor

+Cryo()

AO Enclosure

Particulate Sensor

+Transition()

-State Mappings

StateMachineObject

Motion Controller

+Home()+Position()+Status()

-Limits

Motor Controller

+GetPixelData()

Readback Camera

+Power()

RTC Controller

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Development view (1)

+Configuration Managment()+Acquisition()+Instrument Sequencing()+Fault Detection()+Fault Recovery()+Command Interface()

MSCS

Atmospheric Tools+Offseting()+Dithering()+Nodding()+Pointing()+Offloading Tip-Tilt()+Offloading Focus()+Offloading Coma()

AGOP System

Laser System AO System

+Publish()+Subscribe()

Data Server

MSCS Operator Interface

-Observing Tools

User Tools

+Status()

Health Monitoring

Legacy Interfaces

Instruments LTCSTelescope

Configuration Data

Configuration GUI

Telemetry Telemetry Telemetry

Telemetry

Telemetry

Telemetry Telemetry

Telemetry

Real Time Controllers

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Development view (2)

AO System Telemetry

Configuration

MSCS

Data Server

AO Environment Control

DM Power Controller

Particular Sensor Temperature SensorHumidity Sensor AO Cooling

Vibration Sensor LSG WFS Camera

NGS Acq. Camera Tip-Tilt Sensor

LOWFS TWFS CameraTTFA Camera

NGS WFS Camera

LGS WFS Controller ADC Controller NGS FSM ControllerLOWFS Controller IF FSM Controller Focus Manager Controller

Driver Driver DriverDriver Driver Driver Driver

Driver Driver Driver Driver

RTC ? Driver

Pickoff Controller (x3)

Pickoff Controller (x3)

ADC Controller (xN)

FSM Controller (x2)

FSM Controller (x2) ?????

Driver Driver Driver Driver Driver

AO Sequencer

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Development view (3)

Laser System Telemetry

Configuration

MSCS

Data Server

Laser Environment Control

Laser Safety System

Particular Sensor Temperature SensorHumidity Sensor

Point & Center Camera Beam Quality Camera

Constellation Generator

Driver Driver

Driver Driver Driver

Driver

Laser Steering Controller (x3)

Pointing Controller (x7)

Driver

Switchyard ControllerWaveplate Controller (x7)

Shutter Controller (xN)Driver

Constellation Rotator

Driver

Laser Sequencer

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Development view (4)

AGOP System

Telemetry

Configuration

MSCS

Data Server

Guiding CameraComa Offload ControllerTip-Tilt Offload Controller

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Layered view

• Middleware is the SW that implements the distributed control system

• Wire protocol is the communications protocol used by the middleware

• Middleware API implements the programmer interface to the middleware

• For example, in the Data Distribution Service (DDS), DDS is the middleware and Real-Time Publish-Subscribe (RTPS) is the wire protocol.

Middleware Wire Protocol

Middleware API

Sequencer

User Interface

HealthMonitoring

Utilities

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Middleware evaluation• We are evaluating several

different middleware technologies for use in NGAO

• Evaluation topics:– Services:

• Logging• Data archiving• Alarming• Health monitoring• Configuration• Telemetry• Administration• Event support• User interfaces

– Language support• Python• Java• C/C++

– Communication• Point to point• Multicast• Data support• Synchronous• Asynchronous• Publish-subscribe

– Application development• Inheritance• Loosely coupled• Location transparency• Type mapping

– Performance• Evaluations on 3 PCs• VMWare to easily switch between

environments

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Middleware candidates• DDS – Data Distribution Service

– Uses a Publish-Subscribe paradigm– Is widely used in DoD, so is robust– Available from several vendors (RTI, PrismTech, Gallium)– DDS is an OMG standard

• ICE – Internet Communication Engine– From same group that developed CORBA– Open source (free)– Lots of tools available

• Advanced Technology Solar Telescope (ATST) Common Services Framework– CSF is main controls SW for ATST– ATST are happy to share CSF with us (free)

• EPICS– We are keeping EPICS as a fallback option– We will support (legacy) EPICS interfaces as required through bridges

• Several other candidates have already been rejected:– TINE– TANGO– OpenDDS– OCERA (open source DDS)

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Sequencer concept

• Command – response design pattern– Encapsulates action, parameters, response

• Compound tasks (workflows) are straightforward to build– Simple syntax will allow SAs to write scripts

• Thread pool to handle multiple asynchronous tasks• Easy to build UI around

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Motion control architecture• KAON 643 Motion Control Architecture Study

– Devices fall into natural groupings based on location and control complexity

– Want to match control complexity and cost to the device groupings– No “one size fits all” solution– Cabling will be a real challenge– Architecture will likely be a combination of centralized and distributed

components– We have taken into account the device reductions resulting from the

build-to-cost effort• Main result is reduced device count savings in I&T• No group of devices completely eliminated only modest savings in NRE

– We need more information:• Finalization of device specs: speed, accuracy, payload weight, etc.• Specs on thermal enclosure• Device lifetime requirements

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Device groupings(0) Shutters

– simple in/out devices with very loose positional requirements– actual position when moving is not required

(1) Low precision, non-tracking– moved during configuration, not during an observation– a dichroic or fold, for example

(2) Medium precision, non tracking– moved during configuration, not during an observation– aligning a fold (tip/tilt) or other component

(3) High precision, non-tracking– moved during configuration or acquisition, not during an observation– aligning a lenslet or focusing a unit

(4) Tracking– synchronized to external inputs, constantly moving– ADCs, rotators

(5) Extremely high precision (non)tracking– coordinated motion with other DOF(s), possibly tracking– Field steering mirrors, focus adjustment

(6) Pickoff arms - coordinated high precision (non)tracking– most demanding DOF, coordinated motion with other DOF(s), synched to external inputs– spatial position constraints, based on static and dynamic obstacles, to avoid collision

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Precision

Tra

ckin

g C

apab

ilitie

s

LOW HIGH

Non-Tracking

Tracking

Coordinated Tracking

Type0

Type

1Type

2Type

3

Type

4

Type

5

Type

6

Spectrum of device types

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Location of NGAO motion control devices

21

[1]

[1]

[1]

[1]

[6]

[7]

[14]

[14]

[3]

[7]

[1]

[2]

[1]

[2]

[4]

[1]

[2]

[1]

[2]

[1]

[2]

[2]

[2]

[4]

[4]

[1]

[1]

[4]

[1]

[6]

[3]

[2]

[1]

[1]

[1]

[2]

[1]

[1]

[1]

[4]

[14]

[3]

[3]

[1]

Typ

e 6

[12]

Typ

e 5

[6]

Typ

e 4

[52]

Typ

e 3

[37]

Typ

e 2

[8]

Typ

e 1

[4]

Typ

e 0

[18]

LTO Focus lens (x)

LTO Polarization sensor (x)

LTO Cover (x)

Laser Beam dump (x)

Laser Constellation rotator (θ)

Laser Constellation steering (x,y)

Shutter (x)

BTO Pointing mirrors (x,y)

BTO Centering mirrors (x,y)

Laser Polarization waveplates (θ)

Laser Switchyard shutter (x)

Laser System [56]

NIR Imager ADC assy (x)

NIR Imager ADC (θ,x)

Imagers [3]

NGS WFS Assy Focus (z)

NGS WFS Lenslet (x,y)

NGS WFS FSMs (x,y)

NGS WFS Dichroic (x,z)

NGS WFS [8]

LOWFS TTFA lenslet (x,y)

LOWFS TWFS assy rotator (θ)

LOWFS TWFS lenslet (x,y)

LOWFS TWFS/TTFA unit focus (z)

LOWFS TWFS/TTFA ADC (θ,x)

LOWFS TWFS/TTFA pickoff (θ,Φ)

LOWFS TT unit focus (z)

LOWFS TT ADC (θ,x)

LOWFS TT pickoff (θ,Φ)

Low Order WFS [20]

NGS Acquisition Focus (z)

NGS Acquisition Fold (x)

IF Pointing & centering (x,y)

IF Fold/dichroic (x)

Post Relay 1 [7]

LGS WFS Assy focus (z)

LGS WFS Pickoff (θ,Φ)

LGS WFS Detector focus (z)

LGS WFS Lenslet array (x,y)

LGS WFS Unit rotation (θ)

LGS WFS Unit Focus (z)

LGS WFS [31]

Wyko fold (x, y)

Wyko shutter (x)

Input Image Rotator (θ)

Calibration Source (x,y,z)

Vib Sensor Assly focus (z)

Vib Sensor Lenslet (x,y)

Vib Sensor Pickoff (x)

Hatch cover (x)

Input/Relay 1 [12]

Color Codes: Blue - Cooled AO bench, Green: Off-bench AO device, Brown: Laser enclosure, and Gold: Telescope secondary.

Type 0 - ShutterType 1 - Low precision, non-trackingType 2 - Med precision non-trackingType 3 - High precision non-trackingType 4 - TrackingType 5 - Coordinated trackingType 6 - Pickoff arms

Distribution of devices in the NGAO system

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Motion control recommendations• Architecture:

– Centralized control for high-precision tracking devices– Distributed control for other devices

• Consider device multiplexing for type 0 devices to reduce control infrastructure

• Use smart motors for distributed control where possible. More analysis of the thermal constraints is required.

• Control components should be specified based on device requirements. “One size fits all” will be too costly and may not be feasible.

• HW selection should be done in collaboration with SW designers• HW should support maintenance and troubleshooting. Devices in cooled AO

bench should require minimum support.• Careful considerations must be taken to minimize EMI.• Use COTS controllers and packaging to reduce overall system cost.• Need better device specifications to proceed: Device Description Sheets.• Now is the time to begin collaborations with the design teams.

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Issues

• Lack of information has been the biggest obstacle to date.• Now that B2C effort is drawing to a close, it is time to begin closer

collaborations with the other design teams.• We need as much information as possible on all the devices to be

used throughout the system.• We will be calling to set up meetings/teleconferences to kick off the

process and envision many “working” conferences and calls in the future.