NASA Technical Reports Server (NTRS) 20120006569: Use of CCSDS Packets Over SpaceWire to Control Hardware

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by  NASA Technical Reports Server (NTRS)

signature identification in a heteroge- or RF devices. The processing block con- eral-purpose” intelligent system to accom-
neous environment. sists of several mathematical constructs in- plish the “searching for a source of food
In this architecture, there are four basic cluding Principal Component Analysis while avoiding the predator” function.
blocks: input, output, processing, and stor- (PCA), Independent Component Analysis This work was done by Tuan A. Duong
age. The input block consists of sensing (ICA), Neural Network (NN), Genetic Al- and Vu A. Duong of Caltech for NASA’s Jet
devices including IR, lidar, radar, visual, gorithm (GA), etc., and is controlled by a Propulsion Laboratory. Further information
chemical, and biosensors, at their various hierarchy of logical rules to enact reason- is contained in a TSP (see page 1).
sampling data rates. Based on application ing, reconfiguring, and adapting as re- In accordance with Public Law 96-517,
scenario, selected sensory streams are sent quired when the target is changing in the the contractor has elected to retain title
by the input block to the subsequent “pro- dynamic environment. There fore, the to this invention. Inquiries concerning
cessing” block in a fully parallel fashion. processing block can select an architec- rights for its commercial use should be ad-
Feature data is extracted from the analog/ ture for each particular application as dressed to:
digital sensory streams and is accumulated needed, dynamically, and still remain com- Innovative Technology Assets Management
in the storage block for enriching the patible with a digital environment. The JPL
“knowledge base” as a situation unfolds. conceptualized architecture, capable of Mail Stop 202-233
The incoming raw data is not stored as is extracting knowledge from information 4800 Oak Grove Drive
the usual approach in current computer and using the knowledge for reasoning, Pasadena, CA 91109-8099
architecture, and is reconstructed if re- adapting, and reacting therefore qualifies E-mail: [email protected]
quired during the process in real time. as a cognitive architecture for real-time Refer to NPO-46633, volume and num-
The output block sends the outp ut signal data fusion in a dynamic environment. ber of this NASA Tech Briefs issue, and
to various interfaces (actuating inter- Furtherm ore, its dynamic autonomous re- the page number.
faces), such as other machines, humans, configurability makes it versatile as a “gen-
Programmable Digital Controller
Goddard Space Flight Center, Greenbelt, Maryland
An existing three-channel analog gle error term generated by the capac- The design is based around a new
servo loop controller has been re- itive gap sensor. This was less than opti- generation of direct capacitance to digi-
designed for piezoelectric-transducer- mal when trying to return to the same tal converters from Analog Devices, the
based (PZT-based) etalon control appli- gap position due to the hysteresis of AD7745. This integrated circuit (IC) al-
cations to a digital servo loop controller. the PZT motors and thermal drift in lows the measurement of the capaci-
This change offers several improve- the electronics. tance of the gap capacitor at up to 90
ments over the previous analog con- To overcome the limitations of the Hz with resolutions down to 4 aF. This
troller, including software control over analog servo loop, it was decided that a measurement is an absolute value
proportional–integral–derivative (PID) control loop could be built around a mi- whereas the previous analog design
parameters, inclusion of other data of crocontroller/central processing unit measured capacitance relative to a ref-
interest such as temperature and pres- (CPU), i.e., a digital servo loop. The erence capacitor whose value had some
sure in the control laws, improved ability CPU would query various sensors such as uncertainty. The new design allows one
to compensate for PZT hysteresis and a capacitive gap sensor or temperature to measure the gap directly, after cali-
mechanical mount fluctuations, ability sensor, among others, then based on re- bration, thereby greatly improving over-
to provide pre-programmed scanning programmable control laws, provide a all control.
and stepping routines, improved user in- driving signal to a high-voltage driver This work was done by Gregory J. Wassick of
terface, expanded data acquisition, and that actuates the PZT motor on the Michigan Aerospace Corporation for Goddard
reduced size, weight, and power. etalon. The system is based on mostly Space Flight Center. For further information,
The original analog servo controller COTS (commercial off-the-shelf) hard- contact the Goddard Innovative Partnerships
only had the ability to correct for a sin- ware and software. Office at [phone]. GSC-15524-1
Use of CCSDS Packets Over SpaceWire to Control Hardware
Goddard Space Flight Center, Greenbelt, Maryland
For the Lunar Reconnaissance Orbiter, allel data buses and other types of serial packet contains predetermined values in
the Command and Data Handling subsys- buses, which were not compatible with its payload fields that electronic hardware
tem consisted of several electronic hard- the SpaceWire and the core flight execu- attached at the terminus of the SpaceWire
ware assemblies that were connected with tive (CFE) software bus. node would decode, interpret, and exe-
SpaceWire serial links. Electronic hard- This innovation applies to anything cute. The hardware’s interpretation of the
ware would be commanded/controlled that utilizes both SpaceWire networks and packet data would enable the hardware to
and telemetry data was obtained using the the CFE software. The CCSDS (Consulta- change its state/configuration (com-
SpaceWire links. Prior art focused on par- tive Committee for Space Data Systems) mand) or generate status (telemetry).
14 NASA Tech Briefs, January 2012
The primary purpose is to provide an in- The component parts are the CFE, the “native” CCSDS packets instead of going
terface that is compatible with the hard- electronic hardware attached at the termi- through a translation layer, and it pro-
ware and the CFE software bus. By speci- nus of the SpaceWire link, and the vides a mechanism to control hardware
fying the format of the CCSDS packet, it is SpaceWire link itself. The CCSDS packet features using software constructs.
possible to specify how the resulting hard- is what is produced by the CFE for control This work was done by Omar Haddad,
ware is to be built (in terms of digital of the hardware as well as obtaining status. Michael Blau, Noosha Haghani, William
logic) that results in a hardware design The main benefits of this innovation Yuknis, and Dennis Albaijes of Goddard Space
that can be controlled by the CFE soft- are the ability to re-use existing CFE flight Flight Center. FFurther information is con-
ware bus in the final application. software code, the hardware responds to tained in a TSP (see page 1).GSC-15981-1
NASA Tech Briefs, January 2012 15