A system (11) for monitoring and controlling the movement of a mass (12) along a predetermined path (14) by a motor-driven flexible member (20) is provided to modulate the motor drive output so that the actual velocity of the mass corresponds more closely to the desired target velocity profile. The system...http://www.google.com.tw/patents/US5036266?utm_source=gb-gplus-share專利 US5036266 - Mass velocity controller
