METHOD FOR CONTROLLING DETECTION OF OSCILLATION IN FEEDBACK CONTROL OF INJECTION SPEED IN HYDRAULIC CASTING MACHINE

摘要

PURPOSE: To stably form a product having the prescribed performance by judging what the oscillation generates in the case the max. values in the-stored positive deviation sequentially increase at the setting times or more and also, the min. values in the negative deviation sequentially decrease at the setting times or more, and detecting and controlling the oscillation. ;CONSTITUTION: In the injection drive of a hydraulic casting machine, the deviation between the setting value outputted to a feedback loop and the measured value is calculated and the positive max. value and the negative min. value in the deviation are calculated with a computing element. At the time of changing the positive and the negative in the deviation, the max. value and the min. value are stored and it is judged that the oscillation is generated in the case the max. values in the stored positive deviation sequentially increase at the setting times or more and also, the min. values in the negative deviation sequentially degrease at the setting times or more, and the oscillation is detected. By this method, at the time of generating the oscillating phenomenon in the feedback control, the characteristic, in which the injection movement in the hydraulic casting machine does not converse but disperses toward a target value, is surely detected and thereafter, the prescribed control is executed and the driving can be changed into a safety driving at the early time, and the adverse effect caused by the oscillation is reduced.;COPYRIGHT: (C)1996,JPO