The Optimal Control Of Nonlinear Amplitude Process Of The Combined Arm Gantry

The combined jib luffing mechanism of the portal crane can be regarded as a non-linear transmission,and the transmission ratio of the luffing crane continuously changes with amplitude during the amplitude change process.The conventional luffing speed control system is a completely open loop system.When the luffing motor maintains a constant speed under the control of the driver,the output luffing speed can only be changed non-uniformly by the luffing mechanism after the non-linear change of speed,resulting in In the process of amplitude change,there are problems such as unstable speed and large mechanical impact.The uniform speed and amplitude control mode is an advanced speed control method for improving the amplitude variation of the door machine in recent years.This control mode ensures that the amplitude of the output amplitude is kept constant as the control target,and the rotation speed of the amplitude-modulating motor is adjusted in real-time according to the amplitude of the amplitude change.However,the current constant-amplitude control system only gives some isolated solutions directly,lacks a complete and rigorous theoretical system,and does not see the corresponding optimal control strategy.Some key technologies also have a large room for improvement.This paper combines the dynamic system analysis of luffing mechanism of portal crane with the nonlinear optimal control theory,and proposes a speed regulation control scheme based on the nonlinear state inverse model combined with PID regulation,which can realize automatic constant speed luffing,and the luffing system.The optimal controller has a specific implementation plan design and control parameter tuning.The effectiveness of this control scheme has been verified by a simulation test based on Simlink,and indirect test verification has been performed on a portal crane platform with a reduced scale model.The paper covers the following major research work:(1)The dynamic analysis of the luffing mechanism of the combined boom-type portal crane is completed.The position information of the luffing mechanism is solved.The resulting equivalent ratio I of the luffing mechanism is used as a function of the motor rotation angle.Matlab performs numerical sampling and fitting with polynomials to complete the dynamic inverse model of uniform amplitude and amplitude.At the same time,in order to increase the versatility of the speed regulation program,a VB visualization interface was developed.The corresponding relationship between I and the motor rotation angle can be directly obtained through the input door machine technical parameters.(2)Starting from the nonlinear optimal control theory,it is proved that the uniform speed regulation scheme of the amplitude changing process accords with the optimal control theory,and the implementation of the optimal controller of the variable amplitude and speed regulating system based on the nonlinear dynamic inverse model is implemented.In order to improve the follow-up control performance of the variable frequency motor.Using the PID adjustment that is easy to implement in engineering,the output speed of the variable frequency motor can better track the desired rotation speed determined by the dynamic inverse control law,and the PID parameters can be set using the particle swarm algorithm.(3)Using MATLAB/simulink to verify the effectiveness of the proposed speed regulation scheme for the portal crane.First,establish a simulation model of the amplitude control system according to the optimized speed control scheme,then enter the required parameters for simulation,and simulate the variation of the amplitude change speed when the motor rotation speed is constant and the motor rotates according to the ideal curve,obtain the end of the trunk of the elephant nose the horizontal speed curve change chart and the simulation results obtained are analyzed.The results verify the effectiveness of the door machine variable amplitude optimization speed regulation scheme.(4)In order to verify the effectiveness of this scheme further,a zooming speed test experiment was designed for a reduced type jib portal crane.In the experiment,a variable speed measurement device based on ultrasonic velocity was designed and developed independently.During the test,the change of the amplitude change speed when the motor speed is constant and the motor rotates according to the ideal curve is measured.The experimental results verify the effectiveness of the proposed speed regulation scheme.The optimal speed regulation scheme applied to the nonlinear luffing process of combination jib portal crane proposed in this paper is based on the theory of nonlinear optimal control.The system is tight,easy to understand and easy to implement,and there are clear optimization strategies.Compared with the existing control scheme,the scheme directly uses the output signal of the encoder of the inverter motor as the input signal of the inverse model,and no boom angle sensor is required,the structure is simplified,the cost is reduced,and the reliability is improved.