Theoretical Analysis And Experimental Research On The Hydraulic System Of Remote-controlled Demolition Robot

As a kind of industrial special robot,the remote-controlled demolition robot is mainly used for long-distance remote control and accurate positioning,and realizes the demolition,excavation and transportation of all kinds of bad working environment,and realizes the quick change action.In this paper,in the study of remote-controlled demolition robot,considering the equivalent quality of each arm driving cylinder of the demolition robot has important influence on the stability of the system,and the equivalent mass is also the function of the space posture of the manipulator,in order to ensure the stability of the system,the paper mainly takes the hydraulic system of the manipulator as the research object,The mathematical model is established respectively.The calculation of the maximum equivalent cylinder mass,the selection of a suitable control strategy for the hydraulic system of the large arm,and the compensation of the dead-zone nonlinearity of the hydraulic system of the large arm;At the same time,the prototype experiment was carried out,and the experiment was carried out in time domain and frequency domain characteristic.And the Dead Zone compensation experiment of the small arm hydraulic system,and the results of the theoretical analysis and test results are verified.The main contents of this thesis are as follows:(1)The structure of the remote-controlled demolition robot is analyzed,according to each hydraulic element,the mathematic model is established,and it is integrated into the form of the transfer function of the state equation,and the nonlinear characteristic model of the asymmetric state equation is established according to the non-linear characteristic of the hydraulic dead zone.(2)According to the kinematics and dynamics analysis of the remote-controlled demolition robot arm,the relationship between the equivalent mass of the two arms,the small arm and the rotary hammer arm,and according to the angle range of each arm,the curves of the rotation angle and the equivalent mass are obtained,and then the natural frequency and frequency range of each arm cylinder are obtained,and the simulation response at different frequencies is analyzed.(3)Taking the large arm hydraulic system as the model,based on the analysis of the traditional PID control,the internal model PID control is studied,and the internal model PID control strategy of the hydraulic system is designed according to the internal model PID design principle,and the simulation results show that the internal model PID control has better stability control precision and robustness for the time-varying system.(4)Analyzes the reason of the non-linear characteristic of the remote-controlleddemolition robot,taking the large-arm system as an example,the influence of its dead-time nonlinearity is analyzed,and the static fixed value compensation is used to simulate the dead-zone compensation under the step signal and sine signal.As well as PID control and internal model PID,the dynamic response of the valve-controlled cylinder system with dead zone is compensated.(5)The prototype experiment of the remote-controlled demolition robot,firstly,the range of the proportional multiple valve dead zone of the hydraulic system of the small arm and the rotary motor is measured,then the time domain and the frequency characteristic of the arm,the two arms and the small arms are measured,and the experimental results are validated with the simulation results by the example of the big arm.The correctness of the proposed method for calculating the maximum equivalent quality of the engineering design is verified.Finally,taking the small arm hydraulic system as an example,compensating the small arm hydraulic system with different compensating voltages,the experimental curves under different compensation voltages are obtained and compared with the compensation voltage simulation of the dead area of the big arm,the feasibility of the compensation method is verified.