Dynamic Simulation of the Harvester Boom Cylinder
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machines Article Dynamic Simulation of the Harvester Boom Cylinder Rongfeng Shen *, Xiaozhen Zhang and Chengjun Zhou School of Transportation and Civil Engineering, Fujian Agriculture and Forestry University, Fuzhou 350002, China; [email protected] (X.Z.); [email protected] (C.Z.) * Correspondence: [email protected]; Tel.: +158-0607-7197 Academic Editor: Robert Parkin Received: 25 December 2016; Accepted: 17 March 2017; Published: 17 April 2017 Abstract: Based on the complete dynamic calculation method, the layout, force, and strength of harvester boom cylinders were designed and calculated. Closed simulations for the determination of the dynamic responses of the harvester boom during luffing motion considering the cylinder drive system and luffing angle position control have been realized. Using the ADAMS mechanical system dynamics analysis software, six different arm poses were selected and simulated based on the cylinder as the analysis object. A flexible model of the harvester boom luffing motion has been established. The movement of the oil cylinder under different conditions were analyzed, and the main operation dimensions of the harvester boom and the force condition of the oil cylinder were obtained. The calculation results show that the dynamic responses of the boom are more sensitive to the luffing acceleration, in comparison with the luffing velocity. It is seen that this method is very effective and convenient for boom luffing simulation. It is also reasonable to see that the extension of the distance of the bottom of the boom is shortened by adjusting the initial state of the boom in the working process, which can also effectively reduce the workload of the boom—thus improving the mechanical efficiency. Keywords: boom; hydraulic cylinder; dynamical simulation 1. Introduction Harvesters are employed effectively in level-to-moderately steep terrain for clearcutting areas of forest [1,2]. For very steep hills or for removing individual trees, humans working with chain saws are still preferred in some countries. In northern Europe, small and maneuverable harvesters are used for thinning operations, and manual felling is typically only used in extreme conditions where tree size exceeds the capacity of the harvester head or by small woodlot owners [3]. The luffing movement is usually driven by the modern automobile crane’s hydraulic motor or cylinder. Dynamic force can be generated in the drive system during starting or braking, which is harmful to the safety of the crane, but also to the crane driver’s health. Because of the payload of the suspender, the motion of the pendulum and the dynamic force can be very significant. For this reason, many crane dynamics studies have been reported in the literature [4]. Most of the published articles concentrate on dynamic responses of booms during rotating and hoisting motions, such as Guangfu Sun’s [5] research of the lifted load motion considering changes in rotating, booming, load hoisting, and support system. Chin et al. [6] demonstrated the effects of a platform motion on the dynamic stability of the boom crane. Keum-Shik Hong et al. [7] investigated the influences of transverse and travel motions of a three-dimensional overhead crane system on the payload pendulum. Recently, David Blackburn et al. [8] studied the dynamics of a slewing-crane. The majority of input-shaping theory is based on linear analysis. M.A. Hannan [9] presented a numerical investigation of the nonlinear dynamic response of a fully submerged payload hanging from a fixed crane vessel. Machines 2017, 5, 13; doi:10.3390/machines5020013 www.mdpi.com/journal/machines Machines 2017, 5, 13 2 of 9 Machines 2017, 5, 13 2 of 8 Only a few works have paid attention to the luffing motion of harvester booms. Sawodny et al. [10] proposed a dynamic model for the boom luffing of a rotary crane and used this model to control the payloadOnly a p fewendulum works during have luffing paid attention motion. toHowever, the luffing the model motion is ofonly harvester rigid, without booms. considerationSawodny et al. of [10 the] proposed boom deformation. a dynamic Hirokazu model for et the al. boom[11] showed luffing another of a rotary control crane model and used for level this luffingmodel tomotion control of thea crane payload with pendulum a combination during of luffing feedback motion. and However,feedforward. the However model is, onlythe work rigid, withoutfocused considerationonly on the control of the strategy, boom deformation. and the dynamic Hirokazu behavior et al. [ 11of] the showed boom another was not control considered. model Kilicaslianfor level luffing et al. [ motion12] used of a a multi crane-body with dynamic a combination theory of similar feedback to the and principle feedforward. of “kinematic However, force the” workin the focused crane, onlywherein on the the control amplitude strategy, of andluffing the dynamicmotion driven behavior by of hydraulic the boom waspressure not considered. having a specifiedKilicaslian speed et al. [and12] usedtime ais multi-body assumed dynamicto be cycloid. theory This similar is similar to the principleto the principle of “kinematic of ‘‘kinematic force” in forcing’’.the crane, Because wherein of the the amplitude large inertia of luffingl forces motionof the crane driven structure, by hydraulic for the pressure start-up having and braking a specified of a cranespeed system, and time the is assumeddriving force to be and cycloid. torque This generated is similar by to thethe principlemotor or ofcylinder “kinematic are time forcing”.-complicated Because functions.of the large These inertial driving forces forces of the p cranelay an structure, important for role the in start-up exerting and dynamic braking responses of a crane and system, control the effects.driving In force this and paper, torque the generated luffing boom’s by the motorcylinder or’s cylinder dynamic are behavior time-complicated will be functions.considered. These The calculationdriving forces will play be realized an important for a hydraulic role in exerting harvester dynamic boom. responses Because andthe boom control structure effects. In is thissubject paper, to notthe luffingonly elastic boom’s deformation, cylinder’s flexible dynamic multi behavior-body willdynamic be considered. theory will The be calculationused to describe will be the realized boom luffingfor a hydraulic motion. harvesterThe drive boom. system Because is cylind therical boom, and structure is described is subject using to hydraulic not only elasticand control deformation, theory. Theflexible generalized multi-body cylinder dynamic driving theory forces will bewill used be derived to describe using the the boom virtual luffing work motion. principle. The driveSimulations system ofis cylindrical,crane luffing and motion is described will be usingcarried hydraulic out. As a and numerical control theory.simulation The example, generalized a dynamic cylinder analysis driving offorces the will harvester be derived was using carried the virtualout by work the principle. mechanical Simulations system ofdynamic crane luffing analysis motion software will be ADAMScarried out.—first Asly a numericaldesigning simulation and calculating example, the a dynamic boom, analysissecondly of theanalyzing harvester force, was carried and finally out by calculatingthe mechanical column system stability. dynamic In analysissummary, software the three ADAMS—firstly-dimensional model designing of the and boom calculating was est theablished boom, bysecondly the SolidWorks analyzing software, force, and and finally was calculating imported columninto the stability. ADAMS In simulation summary, software. the three-dimensional The boom’s differentmodel of working the boom conditions was established were simulated by the SolidWorks and analyzed software, by ADAMS and was to imported obtain working into the area ADAMS and stresssimulation situation software. [13]. The The results boom’s can different provide workingthe important conditions parameters were for simulated the assembly andanalyzed design, and by ADAMSprovide a toreference obtain workingfor selecting area reasonable and stress pose situation parameters. [13]. The results can provide the important parameters for the assembly design, and provide a reference for selecting reasonable pose parameters. 2. The Method of Complete Dynamic Calculation 2. The Method of Complete Dynamic Calculation The harvester hydraulic pump translates mechanical energy from the engine into hydraulic energy,The drive harvesters hydraulic hydraulic oil pumpto the translatesmulti-way mechanical valve block energy, and fromthen the, controlled engine into by hydraulicthe cab control energy,, handledrives hydraulics the core oilposition to the multi-wayof the integrated valve block, valve and block then, in controlled accordanc bye thewith cab the control, principle handles of load the sensingcore position control of [ the14] integrated. Its main work valve progress block in accordanceis turning by with rotating the principle bodies, ofmain load boom sensing lifts, control telescopic [14]. boomIts main extension work progress, and other is turning movements by rotating [15,16] bodies,. The worki mainng boom condition lifts, telescopic of the harvester boom extension, boom is relativelyand other movementscomplex. The [15 ,main16]. Thehydraulic working cylinder, condition the of thesecondary harvester hydraulic boom is relativelycylinder, complex.and the telescopicThe main hydrauliccylinder are cylinder, all large the flow secondary