C. Allen Weekley, Consultant      Home

CONTROL

Advanced Sterilization Products – Johnson & Johnson
The client requested completion of a control and measurement system for a sterilization system utilizing a hydrogen peroxide plasma applied to biological indicators in multiple chambers with precise control of vacuum, RF level, concentration, and temperature. The system is used as a biomedical research device. The control and display software is a very large application with many controls, multiple plots, and a completely graphical process sequence builder. The operator can switch between various sets of controls, indicators, and plots using a tabbed control. Hardware is a 96 channel DIO board, a counter-timer, a 16 channel data acquisition system, and a great deal of custom circuitry to control valves, motors, pumps, and generators. Mr. Weekley assumed the project after a series of programmers had been unable to complete the project with the minimum features and reliability desired by the client. Mr. Weekley successfully repaired and completed the software.
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.
Engine Electronics Inc.
The client requested upgrade of an engine dynamometer control and measurement system for Harley Davidson motorcycle engines. Mr. Weekley added hardware and modified software to increase the number and type of measurements. Sensors included thermocouples, pressure transducers, strain gauges, and air/fuel ratio meters. The operator can control the engine throttle and the resistive force of the water brake dynamometer by moving controls on the computer screen with the mouse. The screen simultaneously displays head temperature, block temperature, exhaust pressure, air/fuel ratio, rpm, and calculated horsepower and torque.
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.