Research On Digital Controlled Axial Piston Hydraulic Motor And Its Characteristics

With the continuous development of electro-hydraulic digital control technology,it has gradually become an important development direction to realize the integration of electromechanical and hydraulic,and as an ideal high-speed,high-precision control method of hydraulic system,it has been widely used in important fields including aerospace,engineering machinery and so on.The new digital hydraulic valve is the key component to realize the electro-hydraulic digital control technology,so the research and development of the new digital hydraulic valve is particularly important.Digital hydraulic valve,which is the most simple working principle is based on A series of pulse signal from the controller,the specific can receive digital signal of digital hydraulic valve to control the drive unit,which drives the valve core to movement,to achieve the hydraulic oil in A state of flux,valve opening in the switch,and achieve the function of the control flow through valve opening size,do not need the corresponding D/A conversion interface can realize electro-hydraulic digital control technology.This paper takes the digital hydraulic valve as the research starting point,puts forward a new two-stage digital direction valve structure,and applies it to the axial plunger hydraulic motor,control the inlet flow of the axial plunger hydraulic motor,achieve the effect of controlling the speed.But conventional quantitative axial piston hydraulic motor can’t cope with all have higher torque and rotational speed changes required conditions,therefore this article is based on an oblique type variable axial piston hydraulic motor,designed a new type digital control axial piston hydraulic motor,in addition to its import set up double digital direction to adjust the discharge valve,also in the structure of a new singlestage digital direction valve,replace the original variable institutions of control valve in order to realize the displacement of the digital adjustment,then completes the complex adjustment of axial piston hydraulic motor.In addition,the digital-controlled axial piston hydraulic motor may be disturbed by a variety of non-linear factors during operation.Therefore,the paper designs the corresponding fuzzy adaptive sliding mode control algorithm for the dual valve control system of digital-controlled axial piston hydraulic motor,and achieves a relatively ideal control effect.Finally,the control system for the digital controlled axial piston hydraulic motor is built,which provides the basis for the performance experiment of the prototype.The main research work of this paper is as follows:(1)According to the specific requirements of hydraulic components and hydraulic motors for the specific implementation projects,the structural design of two digital directional valves,the structural design of digital controlled axial piston hydraulic motors,the design of hydraulic system and control system are completed,and the selection design of the important components is carried out.(2)Modeling of the designed digital direction valve,and by using the software AMESim simulation was carried out,and has made the detailed analysis of its performance,and then use digital electrohydraulic control system that is commonly used in three equations,namely the valve port flow equation and flow continuity equation and force balance equation,deduced the state space expression of the digital valve control hydraulic cylinder system,and carries on the simulation.(3)Using the same three commonly used equations,the direction of the digital valve control variable axial piston hydraulic motor inlet flow system to carry on the modeling of related research,establish the corresponding mathematical model,deduced the transfer function of valve control hydraulic motor system,and puts forward the compound control method of variable axial piston hydraulic motor.(4)For the design of the control system,mainly considering the variable axial piston hydraulic motor displacement and inlet flow control,using a variety of control algorithms.Because the hydraulic system generally has the external nonlinear disturbance force,this paper makes a comparative study of several control algorithms through simulation,and analyzes the control effect of the fuzzy adaptive sliding mode control algorithm.(5)The digital control type axial piston hydraulic motor control system is designed in detail,and the construction of the hydraulic motor control system is completed.Then according to the specific control requirements of the oblique shaft variable axial piston hydraulic motor and the digital direction valve,the control software development of the digital control type axial piston hydraulic motor is completed,which lays a foundation for the control experiment of the digital control type axial piston hydraulic motor in the future.In conclusion,based on the existing axial piston hydraulic motor structure is to realize the digital control of axial piston hydraulic motor structure design,structure design of two digital direction valve,control algorithm design and simulation,and completed the construction of the control system and control software development and experimental platform preliminary debugging,for the subsequent numerical control type axial piston hydraulic motor control experiment of a prototype ready.