Estimated Load Signal Processing Method for Hydro-Mechanical Loaders Based on Mathematical Morphology Theory

The hydro-mechanical continuously variable transmission (HMT) loader has high transmission efficiency and large transmission power. Its vehicle speed is decoupled from the engine speed and has high control freedom, but it has the problem of poor load signal quality caused by harsh working environment and high dynamic. In order to solve the above problems, a HMT loader is taken as the research object, the theoretical analysis and simulation research of load estimation are carried out based on hydro-mechanical state parameters. The simulation results show that the method can accurately estimate the load in hydro-mechanical range, and the error is within ± 5.58%. Based on the load estimation method, the actual load of the loader is simulated by the superposition of Gaussian white noise based random excitation of the pavement. In order to eliminate the influence of the random excitation of the pavement in the actual load, the mathematical morphology theory is introduced, the real-time morphological filtering formula is derived, and a load signal processing method based on mathematical morphology is proposed. The simulation results show that the method can filter the actual estimated load in real time, improve the signal quality, reduce the misjudgment of the loader working status, and have better real-time performance with a signal delay of 0.13 s.