REEL TO REEL WEB TRANSPORT CONTROL APPARATUS

• Main Authors: ROBERTS, SPENCER D, LISSNER, RUDOLF W, KOSKI, JOHN A
• Format: Patent
• Language: English; French
• Published: 19.08.1980
• Subjects: CONTROLLING; CONVEYING; HANDLING THIN OR FILAMENTARY MATERIAL; HANDLING THIN OR FILAMENTARY MATERIAL, e.g. SHEETS, WEBS,CABLES; INFORMATION STORAGE; INFORMATION STORAGE BASED ON RELATIVE MOVEMENT BETWEEN RECORDCARRIER AND TRANSDUCER; PACKING; PERFORMING OPERATIONS; PHYSICS; REGULATING; STORING; SYSTEMS FOR CONTROLLING OR REGULATING NON-ELECTRIC VARIABLES; TRANSPORTING

REEL-TO-REEL WEB TRANSPORT CONTROL APPARATUS A reel-to-reel web (tape) transport apparatus which has no tape length buffering between the supply and take-up reels. The tape follows a fixed length path from the supply reel, past a read/write head and guides, to a take-up reel. A two motor control mechanism is employed in which one motor drives the take-up reel and one motor drives the supply reel to maintain the appropriate tension and tape motion at the read/write head. The control mechanism is adaptive to dynamic changes as the tape is moved from the supply reel to the take-up reel. Three quantities are monitored: lineal tape position and the angular reel displacement of the supply and take-up reel. From these quantities reel radii are derived, tape inertia calculated and the velocity or position error is determined. A motor current algorithm is utilized to generate the appropriate torque for each reel to drive the control error to zero along a predetermined profile with negligible tape tension disturbances. The result is a reel-to-reel tape drive with static and dynamic performance characteristics which are independent of reel radius and inertia changes resulting from tape motion.