Capstan drive transport system for motion picture film

• Main Author: Stoker, Mark
• Published: Middlesex University 1992
• Subjects: 620
• Online Access: http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.568742

The work presented describes the development of a capstan drive system for the transport of motion picture film. From a model description of the plant and computer aided system design analysis, control algorithms are formulated. The work shows how these relativity complex control algorithms are implemented by making use of the parallel processing capabilities of the transputer. A critical investigation of current film transport methods is undertaken leading to the design and testing of a prototype capstan drive mechanism. The capstan drive system is shown to eliminate problems of sprocket drives and their associated mechanisms. A multi-input multi-output controller is presented using state-space methods of design. The developed control strategies are fully tested on a model of the plant before hardware testing. The control outputs of the system are speed and tension. The final control solution is shown to be a combination of full-state feedback, integral control, and a Kalman filter estimator for the elimination of system disturbances. The transputer implementation of the developed control strategies is presented together with a comparison between simulation and experimental results. It is shown that computational times can be reduced by using multiple transputers and placing computation-intensive sections of the control algorithm on separate processors. Transputer configurations and interconnections are shown. The capstan system has been shown to allow faster printing speeds with improved transport accuracy leading to better quality of the final picture print. The system has been shown to be 'robust' to external disturbances and changes in plant parameters.