C. Allen Weekley, Consultant      Home

AEROSPACE

Moog Inc. – Schaeffer Magnetics Division
The client requested availability of a consultant to perform software maintenance and modification on an as-needed basis. Mr. Weekley performed ongoing maintenance, modification, and repair of existing software to control cycling and test of stepper motors for spacecraft solar array deployment arms and antenna positioners.
Moog Inc. – Schaeffer Magnetics Division
The client requested troubleshooting and repair of software for automated life cycle testing of a stepper motor for a spacecraft deployment arm. The software is intended to run continuously for very long periods of time but was shutting down in days or weeks. Mr. Weekley identified several poor programming practices that could lead to unexpected shutdown of the software, and modified the code accordingly.
Preece Inc.
The client requested a complete automatic test system for a smart control valve for water flow control for a combustion and fluids experiment on the International Space Station. The product to be tested consisted of a control valve operated by a stepper motor, a flow sensor, and a microprocessor-based controller unit. Mr. Weekley selected equipment, designed interfaces, developed software, and integrated hardware and software based on an HP data acquisition unit, two National Instruments data acquisition boards, a flow computer, a digital I/O board and relay board. An RS-485 serial communications board is used to communicate with a temperature chamber controller. A script-driven test engine was developed, with parameter files read from Excel spreadsheets using ActiveX. Data sheets are also printed from Excel under LabVIEW control. Mr. Weekley simulated the Preece smart valve system and the NASA computer and developed a control algorithm before any prototype hardware was available. Mr. Weekley also set up remote monitoring of test status and temperature control screens. Remote screens are viewable across a network using a standard web browser.
Boeing
The client ordered a test system to perform high rate production testing of a hand-held military transceiver. Mr. Weekley developed instrument drivers and a test executive, as well as writing the software for individual tests. The acceptance test system tests up to four units simultaneously and the thermal test system tests up to 20 units simultaneously. Software used includes LabVIEW 5.0, LabVIEW 4.1, and C. Hardware for the acceptance test system is based on a GenRad Geneva GR2000 with added RF test equipment. Equipment includes a spectrum analyzer, signal generators, a power meter, a bus emulator, an audio analyzer, a GPS constellation simulator, and a VXI counter and DMM. Hardware for the thermal system includes a scanner, a DMM, and DIO card.
Pacific Scientific
The client requested a 12 channel pressure transducer waveform system to monitor the discharge of a fire extinguisher bottle. The client wished to have a system that could be easily re-configured by R&D personnel, and could handle a combination of pressure transducers and thermocouples. Mr. Weekley wrote the software and implemented the system. The software uses the channel configuration capabilities of NI-DAQ and LabVIEW. Hardware is a 32-channel data acquisition card.

Pacific Scientific.
The client requested automation of a complex manual procedure to measure pressure response under a variety of conditions on a space vehicle pressure regulator. Mr. Weekley developed the software and selected and integrated the hardware. The application features a scrolling strip chart display, continuous streaming of pressure and temperature data to disk, automatic acquisition at higher data rates at appropriate times without operator intervention, and the use of LabVIEW to control Microsoft Excel through OLE. Hardware includes a 32 channel data acquisition board and an analog output board. The analog output board was used to simulate the output of pressure transducers and thermocouples so the application software could be developed without the use of the actual pressure test stand. 

Pacific Scientific.
The client wished to replace a plotter and oscillograph with a PC-based automatic data acquisition system. The system is used for testing of a missile pressure regulator. Mr. Weekley selected transducers, designed interface circuitry, and selected the computer and peripherals. Mr. Weekley wrote the software using LabVIEW and the LabVIEW SPC toolkit. Hardware includes an 8 channel data acquisition board, fast response pressure transducers, and a sound card and speakers. 

Pacific Scientific.
The client requested a system to measure high speed temperature waveforms at twelve points in a temperature chamber during the discharge of a fire extinguisher bottle. Mr. Weekley specified the thermocouples and the data acquisition hardware and wrote custom software filters to produce a fast response without excessive noise on the signals. The programming language was LabVIEW and the hardware was a 32 channel data acquisition board. 

Pacific Scientific.
The client requested a portable system to measure gas concentration in an aircraft engine nacelle. Mr. Weekley selected the hardware and developed the software using LabVIEW. The system uses a laptop PC and a PCMCIA data acquisition card to measure the analog voltage output from a gas analyzer instrument and control six solenoids to route the gas flow to the analyzer. The solenoids are operated from the parallel port of the PC. Data is automatically placed in a pre-constructed Excel worksheet and chart. 

Pacific Scientific.
The client requested a system to monitor a temperature/humidity chamber for acceptance test of the chamber and later use in product testing. Mr. Weekley wrote the software in the LabVIEW language. The chamber controller is communicated with using a GPIB interface card.

Pacific Scientific.
The client requested a fire detector acceptance test system. The system measures voltages and resistances for acceptance test of a continuous thermocouple type of fire detector wire. Mr. Weekley developed the application using LabVIEW. The hardware includes a GPIB interface card, a digital I/O board, a DMM with an integral 10-channel scanner, and an 8-channel relay board. 

Pacific Scientific.
The client requested a system to perform in-process test of a continuous thermocouple fire detector wire. The system controls a stepper motor that pulls the fire detector wire through a tube oven, stops at the specified length interval, and soaks at a specified time before taking measurements. Mr. Weekley developed the application using LabVIEW. The system uses a GPIB interface card to communicate with two DMM’s, and communicates with the stepper motor indexer through a serial port.