International Journal of Scientific Engineering and Science Volume 2, Issue 3, pp. 12-15, 2018. ISSN (Online): 2456-7361 12 http://ijses.com/ All rights reserved Computer Simulation of Performance Response of a Digital Audio Tape System Njoku O. Donatus 1 , Nwandu C. Ikenna 1 , Amaefule I. A. 2 , Okafor Ikechukwu Boniface 3 1 Department of Computer Science, Federal University of Technology, Owerri, Imo State, Nigeria 2 Department of Computer Science, Imo State University, Owerri, Imo State, Nigeria 3 Department of Statistics, Covenant Polytechnic, Aba, Abia State, Nigeria Abstract— A computer simulation of performance response of a digital audio tape (DAT) system. The objective of the paper is to design a discrete compensator that will improve the speed performance of the tape drive of a DAT system so that the heads follow the tracks on the tape. This will ensure fast response and accurate positioning of drive heads. In order to do this, a dynamic model of a typical motor/load system of a digital audio tape is obtained. A discrete time compensator is designed using MATLAB software considering a sampling time of 0.1 seconds. The designed controller is integrated into the motor/load loop. Computer simulation was performed for the system for two separate conditions – when the system is uncompensated and when it is compensated. The process parameter values were varied so that three different results were obtained for each of the condition considered. The result obtained show that the response performance compensated system for input a unit step was largely improved. Keywords— Compensator, Computer Simulation, DAT, Step Response, Speed. I. INTRODUCTION At professional level of quality, Digital Audio Tape (DAT) is a known medium and technology for tape recording of audio in digital. It has rotating heads which are similar to those found in video deck [1]. The DAT technology is somewhat close to that of video records, in which rotating head and helical are used to record data. This makes it impossible for DATs to be physically edited in the cut- and –splice manner analogue tapes, or open-reel digital tapes like Pro Digi or DASH [2]. The standard and technology of DAT permits four sampling modes, which are: 32 kilohertz (kHz) at 12 bits, and 44.1 kHz or 48 kHz at 16 bits [2]. Some recorders seem to operate above the specification such that recording is allowed at 96 kHz and 24 bits [2]. In order to move DAT to hard disk, a real-time conversion is required. This depends largely on the machine tape used [3]. The DAT technology was widely used in 1990s for professional audio recording industry, and it is still used in some extent today [2]. As per its use, the format was designed for audio use. Though based on the ISO Digital Data Storage Standard, it has been adopted for general data storage, storing from 1.3 to 80 gigabyte (GB) on a 60-to-180m tape. This depends on the standard and compression. According to [2], it is sequential-access media and is mainly used for backups. As a result of the higher requirements for capacity and integrity in data backups, a DAT of a computer- grade type was introduced which is called Digital Data Storage (DDS). Today, DAT format are still being used regularly in films and television recording. This is largely due to the support in some for SMPTE time code synchronization [2]. Ligthart et al [4] presented design of digital audio tape input output chip. In [3], a digital audio tape (DAT) is presented. This paper has been presented under the following sections: problem formulation, methodology, simulation and discussion, and finally the conclusion of the work. The goal of this paper is to design a compensated system to improve performance response of a typical digital audio tape. II. PROBLEM FORMULATION The relative speeds of the drum and tape is electronically controlled by the tape drive such that the heads follow the tracks on the tape [5]. The DAT control system is more complex than that for a CD ROM because more motor have to be accurately controlled. This includes: capstan, take-up and supply reels, drum, and tension control. A typical DAT is shown in Fig. 1 in which the heads follow the tracks on the tape. It is required to design a speed compensated system for a DAT such that the system must respond rapidly with an overshoot to a step of less than 13% and settling time of less than 2 second with 2 % criterion [5]. The system needs a fast peak time, and such the overdamped condition is not allowed. Fig. 1. Typical digital audio tape (DAT) with track following mechanism [6]. III. METHODOLOGY The mathematical equations of a motor/load system of a digital audio tape (DAT) is obtained and a compensator is designed for the system using Matlab software in this section. The mathematical equations are transformed into transfer functions representing the motor and the load. The motor and