Using IoT Device Technology in Spacecraft Checkout Systems By Chris Plummer Space EGSE Ltd Presentation to DASIA 2015 20 th May, 2015

Using IoT Device Technology in Spacecraft

Checkout SystemsBy Chris Plummer

Space EGSE LtdPresentation to DASIA 2015

20th May, 2015

20/05/2015 Using IoT Device Technology for Spacecraft Checkout Systems 2

Outline of the presentation

• What we are trying to achieve

• The anatomy of a spacecraft checkout system

• What is the Internet-of-Things?

• The anatomy of a ‘thing’

• The development story so far

• Product examples

• Where do we go from here?


What we are trying to achieve• Physically much smaller systems

• Significantly shorter delivery times

• Lower cost systems

• More versatile and flexible systems

• Much better scalability

• Requiring significantly reduced integration effort

• Improved usability

• Greater reuse potential


The anatomy of a spacecraft checkout system - 1

Overall system

Payload SCOE

Power SCOE

AOCS SCOE

DHS SCOE

TM/TC SCOE

Spacecraft Under Test

Checkout System

ControllerEGSE LAN

Hardware Interface Modules (examples)


The anatomy of a spacecraft checkout system - 2

SCOE architecture

SCOE Controller Computer

Pulse Command Outputs

ThermistorSims

1553 Bus

Analogue Acquisition

SpaceWire Links

Back-end LAN Interface to Checkout System ControllerBack-end LAN Interface to Checkout System Controller

Rack Internal Interconnects

Front-end Interfaces to Spacecraft


What is the Internet-of-ThingsThe expression “Internet-of-Things” describes the notion of a collection of embedded computing devices interconnected through the cloud-like infrastructure of the internet.

An excellent example of a real internet of things can be seen with smartphones.

The smartphone is a ‘thing’, the mobile network it attaches to is the cloud-like infrastructure.

But there are many other emerging examples, such as:


What is the Internet-of-Things (examples)• Home automation systems, where the ‘things’ are switches,

lamps, thermostats, motion sensors, etc.• Automotive systems, where cars are the ‘things’.• Patient monitoring systems, where the ‘things’ are medical

sensors attached to patients.• Asset tracking systems, where the ‘things’ are smart tags and

monitoring devices attached to goods.• POS and ATM networks, where the ‘things’ are cash registers and

dispensers.• Video gaming systems, where the ‘things’ are the gaming

consoles, hand controllers, and so on.

And the list just keeps growing!


The anatomy of a ‘thing’

Peripheral Interface Modules (examples)

Embedded Controller/Computer

GPIO Sensor I/Fs (SPI, I2C) USB Analogue

Acquisition

Serial I/Fs (UART, USART)

Wired/Wireless Internetworking Interface

Internal Interconnects

Physical Interfaces to Sensors and Actuators


The development story so far• Identified appropriate technology/devices

• Designed an architecture appropriate for modules applicable to spacecraft checkout systems

• Developed libraries of software modules to enable rapid development of specific products

• Developed early prototypes of what we consider to be key products


IoT Candidate TechnologiesThe key technology of interest is the general purpose SoCs that have been developed to meet the needs of ‘things’ by manufacturers such as Freescale and ST Microelectronics.

These can be classed into a number of families that are mainly differentiated by the core processor they are based on, the number of cores available, and the type and number of integrated peripherals.

Two devices of particular interest have been identified:• Freescale iMX6 series

• STMicroelectronics STM32F4xx series



STM32F407 SoC Block Diagram - 1






STM32F407 SoCTimer Peripheral


Module Architecture

Hardware Interface Modules (examples)

SCOE Controller Computer

Pulse Command Outputs

ThermistorSims

1553 Bus

Analogue Acquisition

SpaceWire Links

Back-end LAN Interface to Checkout System ControllerBack-end LAN Interface to Checkout System Controller

Rack Internal Interconnects

Front-end Interfaces to Spacecraft

Embedded Computer

Module Specific

I/O

Micro-Controller


Software Libraries - 1For the ARM Cortex A9 embedded controller we have a software framework that includes:• Generic TCP and UDP link classes• EDEN and PUS packet handlers• Command handler• Debug interface• XML libraries

In addition, we have an ECSS compliant TM/TC stack including:• Packet, segment, and frame level encoding and decoding for TC and TM• COP-1 dynamically established and maintained on all active virtual channels• TC authentication using NIST800.38B CMAC authentication codes with key

management and anti-replay counters• A range of standard codecs


Software Libraries - 2For the ARM M4 microcontroller we have implementations of:

• RUAG RF bypass interfaces, including TM frame synchroniser• DMA based SPI interface control for variable length message transfer at up

to 42Mbps• Bit-banged 1553 transmit and receive interfaces


Prototype Modules - 1Two prototype modules have been developed:

• A 32-channel thermistor simulator module• A compact TM/TC baseband module

The choice of prototype modules was carefully considered in order to explore the widest range of capabilities and benefits provided by the SoC based modules.

The thermistor simulator was chosen as an example of a low tech, plain vanilla type of EGSE module. We wanted to demonstrate that the SoC technology offered benefits of scalability, and reduced cost-per-channel for simple interfaces.

The compact baseband interface was selected because it is technically challenging in terms of processing and performance in the Cortex A9.


Prototype Modules - 2Both prototype modules have been implemented with surprising ease and are in the advanced stages of testing

In particular for the compact baseband interface, the performance of even the single core i.MX6 SoC proved more than adequate for typical S-band data rates.

Both modules are remotely controlled through an EDEN interface using PUS packets. They can therefore be controlled through dedicated Windows form based control panels, or via the Terma TSC/CCS products.

Integration of the modules into the checkout system is trivial. In the case of using dedicated Windows forms, the control application is simply loaded onto the host computer and started. In the case of a TSC/CCS environment, the provided MIBs and control scripts are simply copied into the test environment and run during a test session.


Product examples - 1There are a number of modules that we think are good candidates for this technology in the future:

• Typical standard interfaces such as bi-level discretes, pulse commands, switch interfaces, etc.

• A debug support unit (DSU) interface module that combines the software load and debug serial interfaces with the discrete control and status signals required for the DSU interface. Combined with the compact baseband module, this would enable early flight software development with minimal EGSE.


Product examples - 2

• Hardware-in-the-loop simulator modules for key components, such as gyros, star trackers, etc. that are form, fit, and function compatible at the electrical level. E.g. an Astrix gyro simulator could provide the discrete pulse and status interfaces, 1553 control bus interface, and RS-422 control and stimulus interfaces on identical connectors to the real unit for use in EMs and flatsat models.

• Multi-channel heater control modules to provide precisely controlled PWM power inputs for test heaters and thermal test dummies


Where do we go from here?We believe that IoT SoC technology can offer huge benefits in spacecraft checkout systems and can achieve the goals set out in this presentation, including reduced size, faster development, lower cost, ease of integration, and so on..Our immediate next steps are to develop the prototypes that we already have into production grade designs. We are in a position where we can rapidly develop new products using our module architecture and the software libraries and will start developing other related products outlined above. We would welcome input from potential customers and users of our products.

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Using IoT Device Technology in Spacecraft Checkout Systems By Chris Plummer Space EGSE Ltd Presentation to DASIA 2015 20 th May, 2015