PODS-100: Portable Data Acquisition System

Preliminary Information v1.1 (26 October 2001)

Introduction

PODS-100 is a low-cost portable data acquisition system designed for flight test applications where quick installation, minimum external sensors and independent power supply are required. PODS will find applications in light aircraft flight testing, land vehicle dynamics and both industrial and academic research and development environments.

PODS-100 is a single box unit measuring 300x200x150 mm which contains its own mains rechargable power supply and a six degree-of-freedom inertial sensor package. On its own it will acquire linear acceleration, angular rate and attitude, barometric altitude and rate-of-climb, together with magnetic field data. Addition of a simple hand-held GPS receiver allows navigation data (lat/long/altitude), inertial velocity, GPS time, magnetic and ground tracks to be recorded, and the supplied data-logging software extracts full attitude and heading reference data.

Also built-in are air data pressure sensors for connection to the aircraft pitot-static system, and an analogue interface which allows up to another 33 parameters to be acquired.

Data recording is either with an off-the-shelf hand-held PalmPilot PDA, or any portable PC with a serial (RS232) port. The supplied Windows software records raw data streams and exports processed data in a variety of formats suitable for importing into Excel or specialised data analysis packages such as Matlab.

Applications

Features

Specifications

Power Supply
  • Internal Nickel Metal Hydride (NiMH) power source provides up to 4 hours continous use, depending on electrical loads applied by external analogue interfaces


  • Spare cell packs may be replaced in the field


  • Internal charger operates off 110-250V AC mains power
Analogue Interface
  • 3 ports of 11 channels each 0-10V 12-bit ADC.


  • regulated 5V (50mA) reference voltage available on all analogue ports


  • unregulated 9.6V (500mA) power supply from internal battery available on all analogue ports
Data Output
  • Proprietary packet PCM format with multi-rate capability and packet verification


  • RS232 format, user-selectable baud rate


  • Multiple receivers may be chained to data output (data recorders and/or telemetry)
Internal Sensors
  • 3-axis solid-state piezoelectric vibrating structure rate gyroscope


  • 3-axis solid-state micromachined silicon accelerometer


  • 3-axis magnetomer using patented magneto-inductive technology


  • Internal static barometric pressure


  • External pitot and static pressures


  • Instrumentation package temperature
External Sensors
  • Any GPS with RS232 output and compatibility with NMEA 2.1 GSA/RMC message format


  • 3 banks of 11 channels analogue input, 0-10V. Channels within a bank must be sampled at the same rate, but different banks may be sampled at different rates. Typical applications include:
    • Remote air data sensors
    • Sideslip & incidence vanes
    • Control stick displacements
    • Control stick forces
    • Control surface displacements.
PODS Programming
  • LCD and keyboard front panel allow selection of output data baud rates, channel enable functions and channel sample rates
Baud Rate
  • User-selectable 9600, 19200, 38400, 57600 or 115200 baud. Maximum usable rate depends on capability of recording device.
Maximum Data Rate
  • Approximately 1000 12-bit samples per second. E.g. 40 channels at 25 Hz.


  • Maximum data rate may be constrained by output baud rate selected. 57600 baud required to support 1000 samples/sec


  • Blocks of analogue data may be sampled at different rates to reduce comms capacity, and not all channels of each block need be recorded. E.g. 3 channels of block 1 at 10 Hz, 5 channels of block 2 at 50 Hz and 10 channels of block 3 at 20 Hz totals 453 samples/second.


  • GPS data is asynchronous and supplied at 1 Hz, so has little effect on overall data rates.
Data Format
  • Proprietary Mini PCM format with multi-rate capability and packet verification


  • Full instructions and sample code supplied. 3rd party applications are encouraged and supported.
Processor
  • Z-World Smartstar system with 25 MHz Rabbit processor.
Temerature Range
  • 0 to +40 deg C (operating)


  • -20 to +50 deg C (storage)

Ordering & Availability

PODS-100 is under development and not yet available. Advance orders may be taken, but delivery schedules can't yet be confirmed. Unit price is estimated to be approximately US$20k. Bulk discounts may apply.