| 摘要 |
<p>To maintain tension on a fiber tow (24) as it travels between a supply spool (38) and a fiber placement head (22) in a computer controlled fiber placement machine (10), closed tension loop servo control tow velocity feed forward controls spool rotation which provides closed loop tension control while varying rotation in anticipation of expected tow movement due to tow payout resulting from commanded movements of the placement head (22). Gain scheduling based on spool radius is also provided. Additionally, a compliant roller (42) reduces tension dips and spikes from disturbances on the tow, and an inner velocity loop, along with the closed tension loop, provides more effective control of tow tension. The servo control is reconfigurable into an open or pseudo-closed loop mode with a safety low power supply which slowly reels-up slack tow after tow threading and maintains low tension on the tow to hold it in the machine during servicing.</p> |
