Research And Development Of Loader's Electronic Position Based On Fuzzy Control

With the rapid development of technology,mechatronics has recently beenapplied on engineering machines widely as a new technique, and has become aprimary developing direction of engineering machines.As an important engineeringmachine,loaders are usually operated in bad environment.To finish theirwork,operators not only manipulate the working equipment continually,but alsoimprove work efficiencyand quality ,which heighten their attentiong highly andfeel tired easily.Because the work resistance that the bucket bears isvariable,operators work in field observation and work by experience,which reduceswork efficiency.For alleviating operators' burden and improving work efficiency,electroniccontrol technique will be applied on the working process of the operatingequipment of loader in this paper.Its Arm and bucket's movement is decided by thework resistance of the bucket,and the control technique of shift angle is fuzzycontrol,thereby the bucket of loader will move in certain workingtrajectory,auto-control of the working process on the operating attachment of loaderis achieved.On the basis of former working equipment structure of loader,this paperputs forward a new electro-hydraulic proportional system,and analyses the workingresistance of the bucket,which provide for fuzzy control system .Based on thetheory analysis of working process of the equipment,single-chip fuzzy controlsystem is established,experiment proves it is correct.1,Electro-hydraulic propotional hydraulic systemLoaders shovel and load material on the arm and bucket,but lifting arm andturning bucket is controlled by hydraulic system.Manipulator use a joystick toopertate former hydraulic cylinder are driven to make cylinders pistons move.The author increases an Electro-hydraulic propotional direction valve, twoelectromagnetism valves, a controled pump and correspond appurtenance, andchange main valve into a hydraulic-controled switch valve,so it constituted theElectro-hydraulic propotional system.This text in consideration of economy, so usetwo propotional valve, use the electromagnetism valve to change the fluxiondirection that in hydraulic oil cylinders.In the improved system of hydraulic system, Electro-hydraulic propotionaldirection valve links to the hydraulic cavity of hydraulic-controled switch valve's port through electromagnetism valve .When it need to put up the arm or turn thebucket, , first openning the correspond electromagnetism valve first, second send acontrol signal to propotional valve, then the liquid of controlled pump move intohydraulic cavity of change toward valve through propotional valve andelectromagnetism valve , the oil push the core to move, thus the oil to flow into thecylinders, make move the arm and the bucket.The The Builting upElectro-hydraulic propotional system, then we can make use of the telectricsignal to control bucket work, for make a foundation of automatic control work.2,self-control principleIn order to make self-control to loader, the most important thing is to judge theaction condition of the arm and bucket.This text discovers that the work resistancehave bigger effect of the train track ,and it decide to work efficiency and energydepletion of the loader ,after studying the relationship between the work equip andthe soil.Therefore, the this text puts forward the condition that max of loader' workresistance as the actions of arm and the bucket at first.The author concleded the relationship that insert resistance of bucket get anddig resistanc , cylinder's pressure of arm, cylinder's pressure of bucket , angle ofarm,and angle of bucket,through analyzing the work equips' structure and pressureit got.The control system of this text design has four pressure, two angle transducers,SCM and controller and front and back chunnel signal dispose electric circuit.Thepressure transducers and angle transducers examines the pressure of cylinder andangle of arm in work process respectively, the datas which is export are after thesignal processing unit, magnified ,after A/D convert, import to singlechip to carryon the resistance calculation.When resistance attains the last enactment, singlechipexport a certainly numerical signal, through the D/A convert to a voltagesignal.Under the function of the valve controller, the voltage signal makes Electro-hydraulic propotional direction valve export a certain hydraulic oil , changingcylinders 'motiong through pushing the core of exchang valve .3,Fuzzy control of angleWhat this text study is a work process that loads adoption shovl-dig method,in this process the angle of arm and angle of bucket need to control.Because thefuzzy control does not need to understand the accurate mathematics model of thesystem so drive extensive adoption, this text makes some regulation rulesaccording to the experiences of operaters of loader, then following the fuzzyconsequence process of person's brain, making a fuzzy decision, to control Electro-hydraulic propotional direction valve's export volume displacementIn fuzzy control of angle, we chose an bidirectional import, single exportfuzzy controller, the datas of importation is error of angle and variety rate of theerror, the datas of exportation is voltage signal to control the Electro-hydraulicpropotional direction valve. The rule is that the arm and the bucket turn 15 degreeeach time.Through fuzzing datas of the importation and exportation,we usedexperience of operate to establish the fuzz control rule list, according toimportation signal choice the correspond exportation signal, through unfuzzyingand outputing the exact datas controling the uncork of Electro-hydraulicpropotional direction valve4,Hardware circuit of control systemThis text make use of the modern micro-electronics technique and pc controltechnique, according to self-controled principle of process of work equipmentwhich was put forward , designed chip fuzzy control system of process of workequipment.This system adopted pressure transducer ,angle transducer.and make useof op07 to establish the magnify circuit.The controller choosed 8 bit single chipAT89C52. AT89C52 do not need to expand programma memorizer and datamemorizer.A/D transformor chosed ADC0809, D/A transformor chosed DAC0832.And emphases introduced the propotional magnify circuit of Electro-hydraulicpropotional direction valve with the core with position feedback , including theslope signal generator, the PID ajustor, oscillator and open-circuit detector, poweramplifier etc..On the foundation of the hardware electric circuit, the plait writes thehomologous software, carrying out the whole function that controls the system.5,SummaryThrough experiment certificate, the text design the singlechip fuzzy controlsystem , it can attain the purpose of control the process of loader,and strengthennedthe gentility and robustness control system and flexibility of control rules. Thissystem is stabile function, it can competent task of process self-control of loader;itcan make loader on the position which was appointed, according to certainly digtrack to carry on the work;It can reduce labor strength of operater, raise the workefficiency of loader and lower the energy depletion.