Taking the valve control cylinder system controlled by proportional relief valve and proportional speedregulating valve as the research object, this paper established a dynamics model of hydraulic system. The friction force of propulsion hydraulic cylinder was compensated based on LuGre model. The bristly observer was established to estimate the motion characteristics of the spool and the stability of the observer was proved by Lyapunov first method. The uncertainty of hydraulic system was integrated with external load interference, and the adaptive rate was estimated. Based on the inverse integral adaptive control algorithm, a pressure-velocity compound control strategy was proposed and the stability of the control strategy was verified. Based on the hydraulic cylinder speed control, the pressure error was introduced into the speed expectation to realize the pressure-flow compound control of valve control cylinder system. The co-simulation platform of the valve-controlled cylinder system was established in AMESim and Matlab, and the speed regulation, sudden load and load disturbance of the valve-controlled cylinder system were simulated and analyzed under different error proportions. The simulation results show that the pressure-velocity composite controller has good control performance under the conditions of speed regulation, sudden load and load disturbance of the valve control cylinder system. The overflow control of proportional relief valve effectively reduces the fluctuation and overshoot of system pressure. Overchanging the proportion of pressure error can effectively change the distribution of pressure and velocity error when the formation changes abruptly. In practical engineering, the distribution of compound control error can be carried out by changing the proportion of pressure error according to the need.

In the working process of large-scale construction machinery such as excavators and shield machines, due to the complex working conditions and changeable environment, the hydraulic system power component axial piston pump of large displacement has greater hydraulic impact than the conventional piston pump, and it causes greater flow pulsation and pressure pulsation. In order to reduce the flow and pressure pulsation of axial piston pump of large displacement under excavation, shield and other working conditions, reduce the impact damage of oil medium on downstream components, and provide theoretical guidance for selecting oil medium methods, this paper built a mathematical model of oil dynamic viscosity, density and bulk elastic modulus based on the influence of temperature field. On this basis, a mathematical model of piston pump with solid-liquid-temperature coupling was established. ADAMS and AMESim software were used to complete the joint simulation of 750 mL/r piston pump under the coupling of solid-liquid-temperature, and the variation law of flow pulsation and pressure pulsation of piston pump under different temperature was obtained. The influence of oil temperature on the pressure pulsation of the piston pump was investigated by the whole pump test, and the correctness of the solid-liquid-temperature coupling simulation model of the 750 mL/r piston pump was verified. According to the three characteristics of oil, the orthogonal test method and the single factor analysis method were used to consider their influence degree and influence law on the flow pulsation rate of the piston pump, respectively. The results show that the outlet flow pulsation and pressure pulsation of the piston pump increase with the increase of temperature. Under the set condition, the influence of oil bulk modulus on flow pulsation rate is 97.19%, the density is 2.03%, and the dynamic viscosity is 0.78%. In order to reduce the influence of oil characteristics on the pulsation rate of piston pump outlet, hydraulic oil with larger bulk modulus and smaller density should be selected.

At present, the installation of steel arch during the construction of tunnel boring machine (TBM) is completed by manual operation, and the working environment is very harsh, thus leads to the problems of low support efficiency, high labor intensity and high construction risk. Therefore, the authors and their team had designed a steel arch rapid-looping installation mechanism to replace manual operation. As the core part of the looping installation mechanism that directly contacts with the steel arch, the grasping module demands sufficient transmission performance to meet the requirements of clamping operation. Based on the screw theory, the paper established a kinematics model of the grasping module, and deduced the virtual coefficient between the input screw and the output screw. Then, the transmission performance of the grasping module was obtained and its transmission index was proposed. On this basis, the size parameter optimization model of grasping module was established. According to the actual grasping requirements of the steel arch looping parts, the optimization results of each size parameter were obtained as follows: the initial included angle between the jaw and the connecting rod is α = 88°, the initial position of the guide rod is l_FJ= 170 mm, and the movement range of the guide rod is 0 ~ 63 mm. Using ADAMS software to analyze the posture change process of the grasping module from clamping to opening, it comes to the conclusion that, the distance between the ends of the jaws gradually increases from 50.0 mm to 234.6 mm, which meets the requirements of grasping space; the output torque increases first and then decreases. When the jaw is fully opened, the minimum torque is 21.23 N·m, which meets the output torque demand. Finally, the steel arch looping installation experiment shows that, the difference between the measured values and the calculated model is only 4.5 mm, which proves the correctness of the model; the whole looping installation time of the steel arch is 8.6 min. As compared with the traditional manual operation, the operation efficiency of the steel arch looping mechanism is improved by 20% ~ 70%.