Research On Human-Machine System Of Excavator Based On User Model

Excavator is an indispensable type of mechanical equipment in the field of engineering construction in China,which has made a great contribution to economic and social development.With the development of science and technology,the research on the operation,safety,and performance of the excavator has made great progress,but the ergonomic problem is becoming more and more prominent.Now some well-known excavator manufacturers of the world have expanded their vision from the pure attention to the function,technology to the human-machine system,such as humanized design,operation comfort and so on.The research on the human-machine system of excavators is a typical solving process about the user-centered multi-disciplinary comprehensive problems,which involves the machinery electronics engineering,vehicle engineering,industrial design engineering,and other aspects of the overlapping knowledge system.Because of the lack of systematic,composite,uniform theory and method,which can’t meet the actual demand of design and evaluation,and have restricted severely the development of excavator brand and product competitiveness.Using the human-machine system of the hydraulic excavator as the research object and the user model as the overall design idea,combining with the ergonomics and perceptual engineering research methods.Meanwhile,we consider fully the functional characteristics of the construction machinery products and propose a new research method which divides human-machine system of hydraulic excavator from the inside to the outside into three layers(dynamic layer,behavior layer,and the visual layer).The design issues of human-machine system at each layer are also explored further.Finally,the overall human-machine system designed is evaluated and applied at last part of this thesis.The main work is as follows:1.In dynamic layer,because it was difficult to identify the weak fault signal of excavator hydraulic system under the background of strong noise,in order to solve this problem,a fault feature extraction method based on Minimum Entropy Deconvolution(MED)and Ensemble Empirical Mode Decomposition(EEMD)was proposed.For the speed and reliability problem of hydraulic system fault diagnosis,an intelligent diagnosis method combining the Extreme Learning Machine(ELM)with the kernel function was also proposed.Through the experimental verification,the method of combining MED-EEMD-KELM could accurately extract the fault features of the hydraulic pump and effectively diagnose the common faults.In order to solving the problem of comprehension difficulty to operation information of machine,a human-machine interface design method based on the user requirements visualization was proposed to provide a platform for establishing a clear,accurate and accessible interactive experience between users and dynamic layer of the excavator.2.For the behavior layer,the layout design and optimization method of excavator cab was studied.By analyzing the parameters of Chinese driver’s body size,the Hip point for the cab layout was optimized,and the Hip point based on the comfortable sitting position was solved also.Meanwhile,the cab layout model based on the driver’s body size parameters was optimized under the analysis of relevant parameter elements of the structural characteristics of the cab of machine.3.For the visual layer,the appearance and color of the excavator was the most direct visual performance,and it was also an important form to enhance the self-developed brand value and improve the self-identity.Aiming at excavator’s design research,this thesis proposed a quality design optimization method based on the users’ preferences.At the same time,according to the quantitative evaluation requirements of color matching of the excavator,a mathematical design evaluation model based on the perceptual image was proposed also.This method could transform the abstract color image into accurate numerical value,which verified the rationality of the optimal scheme theoretically.4.The human-machine system of the excavator was a multi-level,multi-factor,multi-variable,non-deterministic complex system.This paper established a multi-layer fuzzy comprehensive evaluation model of human-machine system of excavator through fuzzy mathematics theory,and the models for the market’s existing excavator products were comprehensively evaluated and compared,which provided a good reference for the rational design and optimal configuration of the excavator.Through the above research work,this thesis studied hierarchically the human-machine system of excavator from a whole point of view,proposed the relevant design method and carried out a comprehensive evaluation,set up a theoretical framework of the human-machine system,which carried out the specific research on the relevant design points.It has certain theoretical significance and engineering practical value for improving the overall design level of excavators in China.