摘要:
A feedback control system which uses estimated back electromotive force (EMF) from a controlled actuator to provide feedback into the control system and improve control of the actuator. Back EMF is estimated from current through the actuator and voltage across the actuator. The estimated back EMF signal is fed back into the control system where it serves as a rate term. In the preferred embodiment the back EMF signal is used in combination with an actuator position signal which is also feedback into the control system. A complementary filter conditions both the rate and position signals for improved performance. The invention is particularly suited for controlling linear actuators which do not provide conventional rate feedback signals.
摘要:
A lapping machine control system which utilizes a electromechanical probe (13) to generate a signal responsive to the separation of the laps (10, 11), which also represents the thickness of the part (13) being lapped. The separation signal, which is unsuitable for direct control since it is too noisy, is used with a best fit algorithm to estimate the time to reduce the part (13) to the desired thickness, based on the rate of material removal provided by extrapolated line (320) representing the best fit of the lap separation signal. The machining is terminated when the extrapolated line (320) reaches the intercept of time (340) and thickness (330).
摘要:
In a die casting machine that includes a shot cylinder having a ram for injecting metal into a die cavity, an electrohydraulic system for controlling operation of the shot cylinder includes an actuator coupled to the shot cylinder ram. A valve supplies hydraulic fluid to the actuator cylinder as a function of valve control signals. Microprocessor-based digital control electronics includes memory for storing a desired ram velocity profile as an incremental function of ram position. The control circuitry is responsive to signals from a sensor coupled to the actuator, indicative of position at the ram, for retrieving corresponding velocity signals from memory and supplying control signals to the valve as a function of such profile velocity signals. The control circuitry further includes facility for adjusting impact of the shot cylinder ram at the end of a cavity-filling stroke as a function of ram and actuator position and/or pressure, independently of the velocity/position profile, to reduce separation and flashing at the die cavity, and to reduce impact wear and fatigue on the overall die casting machine. A keyboard and associated operator display provide operator programmability and selection from a plurality of velocity/position profiles. The actuator and cylinder ram may be advanced in a manual mode of operation for adjustment and calibration proposes. A display associated with the keyboard graphically illustrates desired and actual velocity/position profiles during operation, together with a profile of actuator drive pressure verses position.
摘要:
A servo control apparatus comprising: means for generating a control target; an actuator (3) adapted to drive a load (4) and having its maximum displacement in one direction and its minimum displacement in the other direction; drive means (1, 2) for driving said actuator (3); position detecting means (5) for detecting a displacement of said actuator (3); and control means (21) for correcting said control target on basis of said maximum and minimum displacements of said actuator (3) and for computing a control value so that an output of said position detecting means (5) is consistent with said corrected control target; said load (4) being controlled by said control value.
摘要:
A distributed intelligence control system for controlling a cross direction profile of a traveling sheet (10) includes a scanner (12) for measuring a property of the sheet at a plurality of cross direction locations and producing output signals indicative of the cross direction profile. A host controller (20) coupled to receive the signals from the scanner (12) produces signals representing desired profile information. The system includes a plurality of actuators (26), each actuator being operatively associated with a corresponding intelligent actuator controller (30). A local area network (22) provides a bidirectional communication link between the host controller and the intelligent actuator controllers and between adjacent actuator controllers, the network transmitting to the actuator controllers the desired profile information from the host controller and transmitting between adjacent actuator controllers actual actuator state information, the intelligent actuator controllers calculating target positions based upon the transmitted information.
摘要:
A distributed intelligence control system for controlling a cross direction profile of a traveling sheet (10) includes a scanner (12) for measuring a property of the sheet at a plurality of cross direction locations and producing output signals indicative of the cross direction profile. A host controller (20) coupled to receive the signals from the scanner (12) produces signals representing desired profile information. The system includes a plurality of actuators (26), each actuator being operatively associated with a corresponding intelligent actuator controller (30). A local area network (22) provides a bidirectional communication link between the host controller and the intelligent actuator controllers and between adjacent actuator controllers, the network transmitting to the actuator controllers the desired profile information from the host controller and transmitting between adjacent actuator controllers actual actuator state information, the intelligent actuator controllers calculating target positions based upon the transmitted information.
摘要:
A positioner facilitates docking and undocking of an electronic test head with a device handler. The position provides for rotation of the test head about a first axis. The positioner includes a scissor arm structure for moving the test head along a second axis orthogonal to the first axis