Numerical controller with smooth velocity transition at switchover to servo-on state

• Main Authors: IDEI, TAKASHI, HISHIKAWA, TETSUO, ONISHI, YASUSHI
• Format: Patent
• Language: English; French; German
• Published: 04.07.2007
• Subjects: CASTING; CASTING OF METALS; CASTING OF OTHER SUBSTANCES BY THE SAME PROCESSES OR DEVICES; CONTROL OR REGULATING SYSTEMS IN GENERAL; CONTROLLING; FUNCTIONAL ELEMENTS OF SUCH SYSTEMS; MONITORING OR TESTING ARRANGEMENTS FOR SUCH SYSTEMS ORELEMENTS; PERFORMING OPERATIONS; PHYSICS; POWDER METALLURGY; REGULATING; TRANSPORTING

When a servomotor (control axis) e.g. in a die-casting machine is coasting and rotating in a servo-off state in which no current is applied to the servomotor, this servo-off state is switched over to a servo-on state in which current is applied to the servomotor, and a position control and a speed control are started. An actual speed in servo-on state is obtained in speed obtaining means by a position/speed detector. Position command means obtains a command movement amount using the actual speed as an initial speed. A position deviation amount corresponding to the actual speed is calculated, a command movement amount, a position deviation amount, and a position deviation amount remaining in a position deviation counter in servo-on state with the sign thereof reversed are added to each other as a command amount to the position deviation counter. Thus, abrupt speed changes can be avoided, when position control is started.