| Rock drilling robot is widely used in engineering construction such as tunnel excavation and mining.The control performance of hydraulic drill is directly related to drilling speed and hole quality,and affects engineering efficiency and economic benefits,and it is an important research content in rock drilling field.In this paper,the following research is carried out on the dynamic control of the hydraulic rock drill and the adaptive control of the propelling force.The stress state model of rock under the impact of wedge tooth and spherical tooth is established respectively based on Boussinesq theory,the failure mechanism of different rock under different tooth shapes is simulated by Workbench software,and the relationship between rock failure and impact stress is revealed.The relationship between the impact stress and the impact velocity and the rebound stress of the bit is analyzed by wave dynamics,a mathematical model between the working parameters and the structural parameters of a hydraulic rock drill is established based on impact energy required for different rock failure.The influence rule of flow and external load on the working pressure of the system is analyzed,and the stress state and the energy variation rule during the impact process are obtained through simulation.A method of calculating contact force by using real time detection of rotating pressure is proposed in this part based on the corresponding relationship between the rotary load and the rotary pressure of a hydraulic rock drill,which achieved the indirect measurement of the contact force of the rock drilling robot under the complicated working condition.The rock stiffness is estimated online by the actual contact force obtained,and the influence of the current contact depth error on the control of the steady contact force is analyzed,the Lyapunov stability theory is used to estimate the current contact depth online,and the contact error boundary of contact force impedance control stability is obtained,the regularities of parameter adjustment of the controller is deduced by Lyapunov theory.The influence of the compressibility of hydraulic oil and the asymmetry of the hydraulic cylinder on the precision and stability of the force control are analyzed,a weighted mean method for the effective bearing area of a piston when it is extended or retracted is put forward in this part,and mathematical model of two directions is established of critical center valve-controlled system based on the load flow and load pressure are redefined.A dynamic simulation model of hydraulic drill is built in AMEsim,and the curves of propelling pressure and rotary pressure under different working conditions are obtained through simulation,which provides a theoretical basis for drilling robot adaptive control... |
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