| Excavators are typical construction machinery for earthwork excavation, and the load-sensing(LS) hydraulic system, which is used in the excavators, has low energy consumption, high efficiency. But the load-sensing hydraulic system generally work in the model of one pump driving multiple actuators, when the flow required is greater than the flow which the pump can provide, there will be flow-saturation status, which seriously affects the motor coordination of the actuator, it is necessary to research the flow-saturated resistant technology during multiple actuators in high speed.The virtual prototype model of hydraulic and mechanical systems was created, based on the XCMG 201 C excavators’ platform. The analysis of virtual prototype based on multi-disciplinary co-simulation can make analyzing and optimizing the excavator more quickly, and it can reduce design cycle and greatly improve the quality of the product.The research of this paper as follows:At first, according to the principle of load-sensing hydraulic system, this paper has set up a simulation model of the key components and complete system, three simulations sot were analyzed, and the correctness of the model is verified by the contradistinction of calculation results and simulation results to verify, building the foundation for the next flow-saturated resistant control strategy and co-simulation research.Secondly, based on the apparent characteristics that the difference of the pressure of the bump and the pressure of the feedback reduces, when the load-sensing hydraulic system is in flow-saturation status, this paper has proposed a flow-saturated resistant control strategy of low-cost and high reliability. The control strategy makes the load-sensing hydraulic system in flow-saturation status still having good flow distribution characteristics, which has been verified by the simulation models.Again, the kinematics of the excavators’ mechanical systems was analyzed, and the workspace was defined. The virtual prototype model of excavators systems was created, and by comparing the theoretical results and simulation results of the maximum cutting height, maximum excavation depth and maximum excavation distance on the ground the rationality of the model is verified, providing a mechanical system for the co-simulation model.Finally, the paper has conducted research on the co-simulation of the hydraulic and mechanical systems of the excavators, investigating the approach and set of the co-simulation. The effectiveness of flow-saturated resistant control strategy was verified by the analysis of the co-simulation again. |
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