The Fault Diagnosis Technology Study Of The Hydraulic Excavator Multi-way Valve Group Based On Model Prediction

Recent years, with the enhancement of excavator automation unceasely and the use of electrohydraulic control system widely. On the one hand, it brings out the more complete function and excellent performance; On the other hand, it leads to more complex system, thus it needs to higher requirements for each part in the system. Which the multi-way valve is the key component of the excavator hydraulic system, its performance is related to the quality and technical level of excavator directly. Hydraulic excavator multi-way valve is composed of multiple valves, it has complex oil circuit, mutual interference between each subsystem, many categories of faults and complex coupling relationship between performance parameters of each part, so it is difficult to establish the corresponding relationship between the fault phenomena and causes, therefore it brings out much difficulty to the fault diagnosis and elimination rapidly. In view of the above problem, this paper proposes a fault diagnosis technology based on model prediction about multi-way valve, and the principle is fault identification using residual statistics by comparing the model predicted output and actual output of the detection for the tested valve, this paper carried out the following research work:1. According to the research direction of this paper, refer to a large number of domestic and foreign literature, and participate in the relevant project, familiar with the development of multi-way valve, analyze and understand the advantages and disadvantages of all kinds of fault diagnosis technology, it propose a solution of the fault diagnosis;2. According to the type of the object’s fault, determine the fault diagnosis scheme of this paper, in order to realize the accurate judgment of multi-way valve integrated testing system is established, through the system can real-time monitor to the subjects multi-way valve such as pressure, flow rate of the working oil mouth data;3. Multi-way valve prediction model is established in the AMESim, which was introduced in detail from each league valve to the prediction model established specific steps, and deduced the throttling mouth flow area of the calculation method of valve core, gives the simulation parameters set;4. According to the theory of residual analysis fault judgment method, through the chi-square statistic to set the threshold of failure, so as to judge fault state;5. The relevant fault diagnosis test were completed. According to the multiplex valve flow and pressure signal, by identifying its residual value to judge the fault exists or not, the test results prove that the established prediction model is accurate and true possible fault judgment method.In short, this paper investigates the intelligent fault diagnosis technology of multi way valve by predicting based on the model, and analyzed the typical action of excavator, the results show that the proposed method can identify all kinds of fault about multi-way valve in the case of detecting by the limited sensor quickly and accurately, it provides a new method for fault diagnosis of engineering machinery, and it has definite engineering significance.