Control method for positioning position-pressure of hydraulic cylinder of large-scale forging manipulator

Abstract

The invention discloses a control method for positioning position-pressure of a hydraulic cylinder of a large-scale forging manipulator. The control process comprises the following steps: firstly, an uplift force value uf is predicated according to the weight of a work piece to be as system input; secondly, uf is compared with a practical uplift force vf, PID adjustment is performed according to the difference value e, and a proportional pressure valve is driven through a proportional amplifier to adjust the uplift force P; thirdly, when the practical uplift force V is close to an instruction uplift force, the difference value e is approximate to zero, and the uplift force F of the hydraulic cylinder is controlled to be above an expected value; fourthly, when gravity and forging down force are larger than the uplift force of the hydraulic cylinder, the piston of the hydraulic cylinder is compressed, and the manipulator is moved downward; conversely, the piston of the hydraulic cylinder extends out, and the manipulator is uplifted. The method is characterized in that after the manipulator is uplifted, position feed back signal Vx is compared with expected height value Ux, when Vx is smaller than Ux, the system adopts the conventional pressure control mode; conversely when Vx is larger than Ux, negative feedback cause the reducing of the output pressure, the uplifting of the hydraulic cylinder is stopped, and the system is shifted into the position-pressure control method.

Description

technical field [0001] The invention relates to a forging manipulator, in particular to a position-pressure control method for hydraulic cylinder positioning of a large forging manipulator, which is used for front lifting and buffering control of a large forging manipulator, and solves the problem of hydraulic cylinder positioning under constant lifting force control in a buffering state. Background technique [0002] In the prior art, the traditional large-scale forging manipulator front lift and buffer process pressure control scheme includes the following steps. First, estimate a command signal uf of the jacking force value according to the weight of the workpiece, and use it as a system input. The command signal uf and the actual The difference e of the jacking force vf is regulated by conventional PID control, and converted into a current signal I by a proportional amplifier to drive a proportional pressure valve to adjust the jacking pressure P of the hydraulic cylinder...

AI Technical Summary

Problems solved by technology

These problems are: (1) There is no other positioning mechanism in the front cylinder system. Before the forging operation, the upper force of the hydraulic cylinder cannot be set to completely match the gravity of the manipulator, so the drift of the hydraulic cylinder is uncertain; (2) Different forging operation, workpieces require different initial heights, making adjustment of hydraulic cylinders difficult

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