Engineering topics
Publications and source records attributed to Lokshin, A..
Fuzzy control techniques are analyzed to explain why the fuzzy control that is based on the expert's knowledge is often smoother and more stable than the control performed manually by the same experts. A precise mathematical explanation of this phenomenon is presented. Results obtained make it possible to predict the quality of the fuzzy control.
A new pipelined architecture for autonomous and semiautonomous space robotics systems is described. The architecture uses new concepts which significantly facilitate the overall system performance and leads to an effective functional partitioning between base and remote parts of the system. The base system which is based on a set of parameterized primitives, provides detailed planning and the remote site provides final command binding and resource management. The primitives are then directed to the intelligent manipulation controllers that perform the required manipulation. A proof-of-principle implementation at the JPL Telerobotic laboratory demonstrated the practical efficiency of the pipelined architecture in the context of supervised autonomous robotics operations.
An architecture for implementing the process-level decision making for a hierarchically structured telerobot currently being implemented at the Jet Propolusion Laboratory (JPL) is described. Constraints on the architecture design, architecture partitioning concepts, and a detailed description of the existing and proposed implementations are provided.
It is shown that a simple two-link planar manipulator exhibits a phenomenon of global instability in a subspace of its configuration space. A numerical example, as well as results of a graphic simulation, is given.
Field tests of SETI (Search for Extraterrestrial Intelligence) prototype hardware and software began in March 1985 at Goldstone. With emphasis on the sky survey component of the NASA SETI search strategy, the article describes the survey characteristics, the detection strategy, and preliminary results of system tests.
The SETI Radio Spectrum Surveillance System (SRSSS) will provide a data base for assessing the radio frequency interference (RFI) environment for SETI and minimizing RFI disruptions during the search. The system's hardware and software are described and the sensitivity of the system is discussed.
One component of the NASA search for microwave signals of extraterrestrial intelligent origin will be an all sky survey at a significantly low limiting flux over a broad frequency range. An overall strategy is being designed which will permit this survey to be: (1) carried out using existing antennas in less than three years of observation time; (2) uniform in sensitivity (within 0.5 db) over the celestial sphere for any given frequency; and (3) complete to 6 x 10 to the -23rd W/sq m or better over the frequency range 1.2 - 10 GHz with a frequency resolution of 32 Hz.
The scalloping problem for the case of Gaussian noise statistics is analyzed. The optimal weighting strategy for linearly combining two observations in adjacent beam areas is derived, and the sensitivity and scalloping for this weighting strategy are compared with those realized using a single observation or using equal weighting of two observations. The variation of the probability for detecting ETI signals with scan separation are calculated for the various weighting strategies, assuming that the transmitters are of equal strength and are uniformly distributed throughout space.
The SETI (Search for Extraterrestrial Intelligence) Interpreter Program (SIP) is an interactive software package designed to allow flexible off line processing of the SETI field test data on a PDP 11/44 computer. The user can write and immediately execute complex analysis programs using the compact SIP command language. The software utilized by the SETI Interpreter Program consists of FORTRAN - coded modules that are sequentially installed and executed.