Study On Vibratory Excavation Mechanism, Process Optimization Modeling And Intelligent Control Strategy Of Hydraulic Excavator

Nowadays it is known that there are some difficulties, such as lower energy rate and inadequate work capacity in the excavating process for hydraulic excavator because of conventional excavating pattern and it is very important for hydraulic excavator with high energy consuming from engineering machines how to realize optimum and intelligent control in excavating process. In order to minish directly excavating resistance and energy consuming of hydraulic excavator and enhance work efficiency and self-adaptive capacity, some main research task in this paper such as seeking after a reasonable and effective excavating method for soil and process optimization modeling and intelligent control strategy of hydraulic excavator are completed based on applying vibratory theory to soil excavating process for hydraulic excavator and using theory analysis and experiment research combinatively, and the research fund is obtained from "863 Research Fund[2003AA430200]"(namely mechanics-electronics and manufacture informatization of hydraulic excavator) and "Program for New Century Excellent Talents in University"[NCET-05-0697]. The main works of the paper are expressed as:(1) The characteristic of static intensity and dynamic intensity were studied and excavating principle and invalidation mechanism to soil were discussed. The simulation experiment results about crashing rock and soil process based on dynamic load receal that vibratory impact function dynamic load can improve force method of shovel blade and minish excavating resistance in a big way, therefore, rock and soil can be destroyed even if its stress lower than its destructive intensity.(2) In allusion to fact circs of noise jamming of exciting force signal from the buchet inevitably and the characteristic of noise from exciting force signal in the vibratory excavating process for hydraulic excavator, IMF weight of signal based on the wideband random noisy background is processed using soft threshold method and a signal denoising algorithm for noisy signal is given based on EMD method. The simulation results reveal that the signal denoising algorithm can enhance decomposing veracity of exciting force signal from the buchet, time effect property of extracting instantaneous parameters and can remove availably noise jamming of exciting force signal from the buchet. (3) A online identification algorithm about rock and soil parameters in the vibratory excavating process for hydraulic excavator is given based on LS-SVM. And then online identification about some parameters of soil such as natural frequency was simulated. The results of its simulation and resonant column experiment reveal that the online identification algorithm is of smaller error, better identification capacity and higher identification precision and it is much fit for dynamic systems identification.(4)The impacts on vibratory excavating resistance from the parameters such as exciting frequency, amplitude and inserting velocity were analyzed and the parameters were preferentially matched. Based on matched results, a soft sensing model of vibratory excavating resistance form rock and soil is established by using of orthogonal and extensible function chain neural network and its online self-correction was done accordingly by using of function chain neural network. The application results reveal that soft sensing model is of much high modeling precision and generalization capability.(5) The excavating power consuming models due to different excavating methods such as static excavating, sine wave excavating and triangle wave excavating in the hydraulic excavator is established and corresponding experiments were done. A kind of excavating method with better effect in saving energy aspect than other excavating methods was gotten.(6)An intelligent control system for vibratory excavating in the hydraulic excavator was designed by using of combinative expert control, non-linear PI controller and single neuron and its parameter can be tuned based on self-adaptive particle swarm optimization algorithms. The control tactic of executive machine for vibratory excavating was submitted based on Ultronics control valve with double cores and its data communication and control model application were studied.(7)An experiment platform for vibratory excavating rock and soil in SWE85 hydraulic excavator is set up and the stability of control system for vibratory excavating, the respond characteristic of high frequency, the applicability of control strategy, excavating resistence and power consuming were studied by using of the experiments. The experiments results reveal that the vibratory excavating control system in hydraulic excavator is of better stability and rapid capability and can ensure that excavating resistence depress to 70% and power consuming depress to 80% when exerting sine wave vibratory methods.In a word, a new vibratory excavating method for the hydraulic excavator was studied by the numbers in the paper and some research achievements with higher applied price were gotten, which can offer steadier theory basis for practicability.