Proposal

Proposal

Table of Contents:

PROJECT TITLE: PC-Based Control of Theater Stage Machinery (Spring 2000)

OBJECTIVES

This project will build upon and integrate previous research efforts. Summer work in 1998, partially sponsored by CASA, has produced the first live performance ready version of the interface software written under the LabVIEW development environment for automation and data acquisition. This interface currently allows operator control of position and speed for a single motion axis of motorized scenery or similar stage effect. Interface to the electro-mechanical component of the effect is through an industry standard ±10vdc control signal and an incremental optical shaft position encoder via a PC bus data acquisition card. The operator can record, edit, and playback motion "cues" much as with standard stage lighting consoles. The on screen display offers graphical input and feedback of the control variables. The system has already been tested successfully in performance in the Fall 1998 Theatre and Dance Department production of Home on the Mornin’ Train. The system will also be featured as part of an invited presentation at the United States Institute for Theatre Technology Conference in March 1999.

During the CASAbbatical period, specific development will include:

Programming routines that will allow a software interface with commonly available dedicated hardware-based motion controllers. This will add significant stability to the current system and allow operation on less powerful CPUs by relieving the host PC and the HMI software of many calculation-intensive tasks. HMI to hardware controller implementation will also broaden the base of potential users for the system; at least three off-the-shelf motion controllers will be included in this phase of the research.

Refinement of the HMI’s "cueing" system to allow linked and multi-part motion routines along with a decimal numbering system that can be "read" by other controllers. This will also enable the utility of inserting, deleting, and re-ordering an existing cue sheet.

Implementation of software routines that allow remote command and cueing of effects using a typical performance interface -- MIDI (Musical Instrument Digital Interface) Show Control. Some of the groundwork for this phase of the project was part of a summer research project and presented two years ago at CASA.

Additional performance testing by an outside professional producing organization such as a regional theater company.

METHODOLOGY

Success for the project must begin with following each thread in the research above independently, and hooking them to the HMI as each is realized. While programming in the current development environment is generally quick (indeed, that is why it is useful), the size and complexity of some of the work requires the amount of unbroken time that the CASAbbatical period will afford.

--The hardware implementation phase requires the most investigation into new (at least for this researcher) skills. Specifically, this means developing familiarity and facility with the real-time extensions to the WindowsNT operating system. These are crucial to both the live-performance aspect of the system under development, but also to the stability of a system designed to control large (and therefore potentially hazardous effects). Real time interface modules to the hardware will be programmed using OLE for Process Control (OPC). OPC in combination with National Instruments Component Works development system gives the HMI access to various manufacturers control protocols. The programming itself should take easily a month of full-time work. But, since the three different hardware devices represent three different but common implementations of real-time control, mastery of these components will ensure that implementation on other manufacturers hardware is possible. One Performance Motion Devices four-axis board is already in house being integrated with the HMI as time allows. The other two boards (with somewhat more sophisticated capabilities) will be acquired as part of the CASAbbatical award.

--The current implementation of the HMI only offers one-axis of control. Given that most effects in live performance may require simultaneous motions, the graphical interface must be expanded to accommodate them. This should prove to be a quick addition once the hardware interface is complete.

--The second thread above, refining the cueing system, requires rebuilding the data storage structures used in the current application. As the data types now in use are implemented properly already, this, too, should finish relatively quickly. A more flexible, randomly accessible data structure will allow for future expansion of the cue information in future versions.

--Remote synchronization and cueing of the system by a master show controller (one that can trigger any number of theatrical events including sound, lighting, and pyrotechnics) requires that it "speak" MIDI Show Control (MSC). Implementing this will require two things: 1) writing routines in the National Instruments "G" language that will parse MIDI messages or recompiling some existing open source code to allow their use in the development environment. As this is a relatively self-contained programming project, it will best be handled by a research assistant. 2) Building hooks into the HMI that will handle MSC messages. Again, the assistance of a programming assistant will make this phase of the work possible within the CASAbbatical period.

--Much of the work on this project can and will take place in the CASA laboratory space. This will be true especially when exercising and troubleshooting the system with the motorized bench-top test bed currently in use in that facility.

ANTICIPATED RESULTS

As this is a project designed for use in live performance, its viability is best tested in such a venue, and there are several outlets for this. While productions within the college of Fine Arts will provide an adequate first laboratory for trials, the true viability will be determined in the hands of professional technical personnel at an outside professional producing organization such as a regional theater company. The artists working at these venues are those most in need of this technology. Indeed successful adoption of this system by these organizations will be an indicator of success for the project. Part of the CASAbbatical period may need to be spent in traveling working on the project with members of these organizations. As this is still unknown, no travel funds are allocated yet for this.

This project will also be submitted for presentation at the USITT Conference in Spring 2000, as this organization of professionals in technical theater host invitational sessions on new technology. Publication on the project would not be likely until after this event.

The research will be visible to this University community both through production in the College of Fine Arts as noted above, as well as events like the open houses sponsored by CASA in past years.

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