Fuel economy of multiple conditions self-adaptive tractors with hydro-mechanical CVT

Transcription

1 102 May, 2018 It J Agric & Biol Eg Ope Access at Vol. 11 No.3 Fuel ecoomy of multiple coditios self-adaptive tractors with hydro-mechaical CVT Maohua Xiao 1*, Jig Zhao 1, Yuewe Wag 1, Haiju Zhag 1, Zhixiog Lu 1, Weihua Wei 2 (1. College of Egieerig, Najig Agricultural Uiversity, Najig , Chia; 2. College of Mechaical ad Electroic Egieerig, Najig Forestry Uiversity, Najig , Chia) Abstract: Fuel ecoomy is oe of the most importat properties of wheeled tractors. To improve the fuel ecoomy, it is ecessary to improve the egie fuel ecoomy ad the tractive efficiecy of the drivig mechaism. By aalyzig the fuel ecoomy evaluatio idex of wheeled tractors, the correlatio amog the tractor specific fuel cosumptio, the egie effective specific fuel cosumptio ad the tractive efficiecy of the drivig mechaism were clarified i this paper. A tractor with a ew type of hydro-mechaical cotiuously variable trasmissio (HMCVT) was desiged ad its whole model was established too. O the basis of each module s simulatio model, the biary speed ratio matchig simulatio model of the gearbox-egie system was obtaied by the cotrol system recostructio, ad the fuel ecoomy simulatio aalysis of the wheeled tractor with HMCVT was carried out uder the two typical workig coditios of plowig ad sowig. Compared with the curret atioal stadard, the fuel ecoomy of the ewly desiged wheeled tractors with the power of 130 kw was 380 g/(kw h), specific fuel cosumptio was reduced by 21.1%. The results showed that the ew tractor fuel ecoomy was greatly improved. Further, automatic avigatio techology ca be combied with the self-adaptive tractors to adapt to differet workig coditios ad achieve the optimal fuel ecoomy, which ca be applied i precisio agriculture. Keywords: high power wheeled tractor, self-adaptive tractor, HMCVT, fuel ecoomy, avigatio DOI: /j.ijabe Citatio: Xiao M H, Zhao J, Wag Y W, Zhag H J, Lu Z X, Wei W H. Fuel ecoomy of multiple coditios self-adaptive tractors with hydro-mechaical CVT. It J Agric & Biol Eg, 2018; 11(3): Itroductio Agricultural tractors are oe of the machies i agricultural productios which have great importace. Obviously, the machie workig efficiecy shall be raised to icrease efficiecy of agricultural products. Due to the limitatio of oreewable fossil eergy sources, it is essetial to optimize fuel cosumptio. Therefore, the study to improve the high power wheeled tractor s fuel ecoomy to fit the eeds of the ew era is of great sigificace. From the perspective of fuel ecoomy, there are may methods for the gearbox ad the tractor respectively. A ew combied scheme hydro-mechaical cotiuously variable trasmissio had bee proposed, which cosisted of a itegrated hydraulic torque coverter, chai cotiuously variable trasmissio, reductio gear set ad correspodig cotrol istitutioal compositio [1]. Pa et al. [2] proposed a method based o the maual gearbox speed ratio optimizatio, ad by comparig the ratio before optimizatio ad after, it was foud that the fuel cosumptio was improved by 1.83%. Cai et al. [3] proposed a shift guidace system based o the Received date: Accepted date: Biographies: Jig Zhao, MS cadidate, research iterest: computer visio, @qq.com; Yuewe Wag, MS cadidate, research iterest: tractor eergy cosumptio, @qq.com; Haiju Zhag, PhD cadidate, Associate Professor, research iterest: mechaical optimizatio desig, zhhj@jau.edu.c; Zhixiog Lu, PhD cadidate, Professor, research iterest: vehicle electroic cotrol techology, luzx@jau.edu.c; Weihua Wei, PhD cadidate, Associate Professor, research iterest: high-performace cuttig techology, whwei@ jfu.edu.c. *Correspodig author: Maohua Xiao, PhD, Associate Professor, research iterests: itelliget agricultural machiery ad equipmet. College of Egieerig, Najig Agricultural Uiversity, 40# Diajiagtai Road, Pukou District, Najig , Chia. Tel: , Fax: , xiaomaohua@jau.edu.c. best fuel ecoomy. The system validity was verified, the results show that the system average fuel cosumptio is up to 8.6%, ad ca make the fuel cosumptio level more stable. Not oly the gearbox, but also the fuel ecoomy of its carrier has bee widely studied. The theory behid tractor usage offered a sufficiet umber of scietifically grouded criteria that characterize agricultural power uits with respect to their particular properties [4]. Oe of these characteristic values was used most widely ad, i the majority of cases [5], it decided ad determied the choice of a particular tractor-this beig its egie power ratig [6,7]. A method had bee proposed i various papers for determiig a tractor s miimum required operatig mass [8], this mass ad its egie power ratig related to the aalysis of geeral power balace. A characteristic feature of this method was the due cosideratio give to the o-liear depedece of the power uit s ruig gear slip rate o the drawbar pull, which was delivered by it [9]. I order to study the fuel ecoomy of tractor uder multiple operatig coditios, may models have bee established. Automobile fuel ecoomy calculatio model was established to simulate the fuel ecoomy [10]. Ji [11] iveted a assessmet method ad fuel ecoomy device, the assessmet method iclude the establishmet of multiple regressio models. The ivetio ca evaluate the automobile fuel ecoomy accordig to the drivig data iformatio correspodig to the o-ecoomic process of the automobile fuel. Zhou et al. [12] established a trasiet fuel cosumptio model with "steady-state iitial estimate + trasiet correctio", ad the slope ecoomic optimizatio algorithm was obtaied. At preset, a visual basic program was developed to determie the optimum gear ad throttle positio o the basis of miimum fuel cosumptio per hectare for plowig, cultivatig ad harrowig operatios. The program provides a ituitive

2 May, 2018 Xiao M H, et al. Fuel ecoomy of multiple coditios self-adaptive tractors with hydro-mechaical CVT Vol. 11 No iterface by likig database such as tractor, tire ad fuel cosumptio model, soil ad operatig coditios to predict the miimum fuel cosumptio of selected model [13]. However, some models caot fully cosider the effects of may factors o ecoomic performace. The vehicle mai parameters ifluece o the fuel ecoomy was aalyzed, ad its sesitivity was studied too. Further, a ew evaluatio method-the weighted average method was applied to calculate the automobile fuel cosumptio. Various factors affectig the car fuel cosumptio were take ito accouts, such as road coditios ad load, which helps to form a more accurate fuel ecoomy evaluatio [14]. A study was coducted to ivestigate the effects of five cotrol variables: ballast, tyre iflatio pressure, trasmissio gear, egie speed, ad workload o three fuel efficiecy parameters: fuel cosumptio per work hour (FC), fuel cosumptio per tilled area (FCA) ad specific volumetric fuel cosumptio (SVFC) [15]. For determiatio of tractio properties of a wheeled tractor vehicle, it is essetial to determie directios ad values of power flow through the wheels. These i tur deped o the forces ad momets applied to a give wheel as well as the type ad coditio of the groud uder the wheel [16]. Most previous researchers idicate that about 20%-55% of available tractor power is lost i the process of iteractio betwee tires ad soil surface. Vertical wheel loads ad tire performace are parameters that play a sigificat role i cotrollig slip ad fuel cosumptio of a tractor [17]. Based o the positive developmet process of vehicle products ad the whole vehicle s performace itegratio techology, Gao et al. [18] established a ew developmet process based o eergy flow ad performace itegratio techology. Curretly, the study o fuel ecoomy is basically i the field of automobile, but the research o high power wheeled tractors is isufficiet. I view of that, the study proposes the biary speed ratio matchig simulatio model of the gearbox-egie system to simulate the fuel ecoomy of high power wheeled tractors. 2 Fuel ecoomy evaluatio idex of wheeled tractors The specific fuel cosumptio g T is a idicator to evaluate the tractor fuel ecoomy. It refers to the amout of fuel (g/kw h) cosumed by the tractio power of per uit kilowatt hour whe the tractor is operatig. The equatio is show i Equatio (1): GT 3 gt = 10 (1) PT where, G T is the tractor hourly fuel cosumptio, kg/h; P T is the hook tractio power, kw. G T G e, P T = P e η T (2) where, G e is the egie hourly fuel cosumptio, kg/h; η T is the tractor pullig efficiecy. ge gt = (3) ηt where, g e is the egie effective fuel cosumptio rate, g/kw h. It ca be see that the tractor specific fuel cosumptio is related to the egie effective fuel cosumptio ad the tractive efficiecy of the drivig mechaism. From the above aalysis we ca see that the tractor fuel ecoomy depeds o the egie fuel ecoomy ad the tractive efficiecy of the drivig mechaism. Therefore, i order to improve the tractor fuel ecoomy, it is ecessary to improve the egie fuel ecoomy ad the tractive efficiecy of the drivig mechaism. 3 Research o wheeled tractor with HMCVT 3.1 Trasmissio scheme priciple of HMCVT The HMCVT developed by our team is applied i the high power tractor. The selected egie is WP6T180E21 [19], a kid of pressurized, cold, high-pressure commo rail EFI egie. The uiversal features are show i Figure 1. The figure shows that the maximum output of the diesel egie is kw, the idle speed is 750 r/mi, the rated speed is 2200 r/mi, the miimum fuel cosumptio is less tha 204 g/(kw h), ad the optimal ecoomic speed is about 1500 r/mi. Accordig to the demad of low-speed heavy load uder the plowig ad other coditios, the miimum speed is desiged to be 4 km/h ad the maximum speed of the tractor to be 20 km/h, takig ito accout the icreasig speed of tractors i idustrially developed coutries [20] as well as the growig tred i double fuctio of the operatig machiery ad trasport machiery. I geeral, tractors are used primarily for trasportatio above 20 km/h. Tractor speed of differet operatig modes is show i Table 1. The rear axle mai reductio trasmissio ratio is 3.7, side reductio trasmissio ratio is 5.6. That is, the total trasmissio ratio of the rear axle is set at The diameter of the drive wheel is 1835 mm, ad the dyamic outer diameter is coverted to be 1716 mm i accord with of the tire outer diameter [21]. Figure 1 WP6T180E21 diesel egie uiversal features Table 1 Tractor speed of differet operatig modes Load Operatio mode Speed/km h -1 Heavy load Medium load Light load Trasportatio Plowig 5-10 Rotary tillage 5-12 Potato harvest 4-8 Pulverizatio 3-12 Itertillage ad rippig 4-14 Harrowig 4-13 Frot loadig 4-10 Ridgig 4-12 Sprayig 6-12 Mowig 5-20 Fertilizer spreadig 5-17 Sowig 6-15 Postharvest surface 6-12 Substatial soil 8-28 Asphalt pavemet 12-48

3 104 May, 2018 It J Agric & Biol Eg Ope Access at Vol. 11 No.3 The gearbox desiged accordig to the above parameters is a four-stage double-row plaetary coverget HMCVT, the drivig priciple is show i Figure 2. I the picture, g1-g12 is the gear pair, the trasmissio ratio is i1 - i12; P1, P2 is the plaet row, the characteristic parameter is k1, k2; c0-c5 is the wet clutch, its bodig ad separatio cotrolled by the oil pressure. It ca be see from the figure, the egie power is divided ito two steps after eterig the gearbox: oe goes through (whe back drivig is g1) gear pairs g2, g3 ito the plaets P1, P2; Aother way is through the gear g4 ito the lie-motor volume cotrol circuit, ad through the motor shaft ad gear g5 ito the plaets P1, P2. Two-way egie power coverged at the plaetary row P1, P2 ad the differetial output. As the mechaical trasmissio ratio is ot adjustable, ad the volume goveror circuit trasmissio ratio ca be adjusted by the swash plate agle of variable pump, it ca make the etire gearbox speed chage cotiuously with the variable pump displacemet. After the two-row plaetary cofluece, the egie power output backward through the g6 to g9 gears, resultig i four stalls, called sectio, each sectio of power output to the gearbox rear selectively through egagemet ad separatio of c1 to c4 wet clutch. Figure 2 Trasmissio schematic diagram of the HMCVT 3.2 Theoretical aalysis ad test of HMCVT regulatio Theoretical calculatio By the plaetary gear speed characteristic Equatio (4), that is, the su wheel speed is s, the gear rig speed is r, ad the plaet carrier speed is c, its characteristic parameter k satisfy the followig equatio: s + kr (1 + k) c = 0 (4) The plaet carrier output speed c is: s + k2r k245 i i εi23 i c = = (5) 1 + k2 (1 + k2) i2345 ii i The rotatioal speed 13 of the clutches c1 ad c 3 is: c k245 i i εi23 i = e HM1 i8 (1 + k2) iiii = (6) c k245 i i εi23 i = e HM2 i9 k245 i i εi23459 iiii The gearbox output shaft speed k is: 13 k2i4i5 εi2i3 = i (1 + k ) iiiiii k = 13 k2i4i5 εi2i3 = i (1 + k ) iiiiii e e HM HM Similarly, gearbox output shaft speed HM2 ad HM4 h are: 1 3 (7) h r (1 + k2) i4i5 + εi2i3 = e ii 711 kiiiiii HM 2 13 (1 + k1) i4i5 εi2i3 e i12 kiiiiii HM 4 = = Whe the egie speed is 750 r/mi, 1000 r/mi, 1500 r/mi, 1900 r/mi, 2200 r/mi respectively, the speed cotiuity of each sectio are calculated, the results are show i Figure 3. It ca be see from the figure that the gearbox ca be co-cotrolled by variable system displacemet ad clutch iterruptio cotrol to achieve cotiuously output speed, ad the output speed remais uchaged i the exchage before ad after. To some extet, it is able to avoid the speed impact whe chagig sectios ad esure the drivig ad ridig comfort Regulatio test of HMCVT The HMCVT regulatio feature is its most basic trasmissio characteristic, as show i Figure 4. The tests are carried out respectively at 750 r/mi, 1000 r/mi, 1500 r/mi, 1900 r/mi. The gearbox speed is ot affected by the egie speed ad speed characteristics, but oly affected by the pump-motor displacemet ratio ad the workig sectio, so it is feasible to set the egie test speed at idle speed 750 r/mi. The test is carried out i the hydro-mechaical sectio. The test bech is show i Figure 5. (8)

4 May, 2018 Xiao M H, et al. Fuel ecoomy of multiple coditios self-adaptive tractors with hydro-mechaical CVT Vol. 11 No Figure 3 Speed characteristics of HMCVT uder differet iput speed Figure 4 Test result of speed characteristics of the HMCVT [22] Figure 5 Test bech The compariso betwee the data of experimetal ad theoretical is show i Table 2. It is highly cosistet betwee two data, therefore, the correctess ad reliability of the gearbox desig scheme are verified theoretically. 4 Study o fuel ecoomy of the self-adaptive wheeled tractor with HMCVT The speed ratio matchig betwee HMCVT ad egie system has bee discussed. The purpose of speed ratio matchig is to achieve the tractor fuel ecoomy, therefore, the gearbox ad the egie should be cosidered as a whole. Through the establishmet of the mechaical model icludig the HMCVT, the simulatio ad aalysis of biary ratio matchig of the gearbox - egie system, ad the gearbox stepless regulatio uder the typical coditios of plowig ad sowig is obtaied to study the ratioality of matchig strategy. Cosiderig the highly itelliget electroic cotrol uit of gearbox, speed ratio matchig is its core cotet. I practical work, the optimal speed ratio ca be obtaied by calculatig the curret operatig coditios usig avigatio techology ad set it to the process cotroller, ad the the tractor fuel ecoomy ca be achieved. I the cotext of precisio agriculture (PA), the applicatio of autoomous avigatio to agricultural vehicles for precisio farmig is regarded as a successful example, with drastic potetial improvemets i agricultural mechaizatio [23]. Automatic avigatio for agricultural vehicles is oe of the key techologies to realize precisio farmig operatios, such as platig, fertilizatio, sprayig, tillage, cultivatio [24]. Applyig the automatic avigatio to the study ca achieve better agricultural productio. The combiatio makes it possible to feedback data to the cotroller uder differet operatig coditios. The tractor immediately realizes variable speed to achieve the lowest fuel cosumptio rate.

5 106 May, 2018 It J Agric & Biol Eg Ope Access at Vol. 11 No.3 Table 2 Experimetal data of trasmissio ratio characteristics of the HMCVT Gear Displacemet ratio Experimetal data Theoretical data cotrol but do ot care about the dyamic process, as log as it ca achieve the basic autoomous adjustmet fuctio. The cotrol system model is show i Figure 8. HM1 HM2 HM3 HM Rotary iertia of each axis Gear pair Plaetary row Wet clutch; 31. Variable system 32. Fixed displacemet motor 33. Oil accumulatio Safety valve Oe-way valve 38. Overflow valve 39. Fuel tak. Figure 7 Simulatio model of the HMCVT 4.1 Costructio of the simulatio model I the Power Trasmissio library, a special four-stroke egie model is itegrated. This model takes full accout of the o-liearity of the combustio ad compressio processes durig egie operatio ad the ifluece of the acceleratio process, etc. It is clear that this model is very suitable for the study of egie dyamic characteristics. However, for this study, more attetio is paid to its steady-state characteristics ad the gearbox-egie matchig problem. Therefore, usig the existig library models directly may result i a large matchig error. I order to solve this problem, the egie mathematical model has bee build based o the egie characteristics ad the most basic sigal compoet library Sigal Blocks, as show i Figure Ratio poit sigal of target speed, whose value depeds o the matchig strategy 2-3. Icremetal calculatio module ad the output is +1 or Variable poly displacemet calculatio module, the output is from 1 to Trasfer fuctio Z -1, for the feedback of the curret speed ratio poit 7. is the poit query table Off Sigal of clutch Process trasfer fuctio Oil coversio module Speed ratio calculatio module Calculatio module of systematized fuel cosumptio. Figure 8 Process cotroller model of the HMCVT 1. Egie oil opeig sigal 2-4. Matchig output sigal of gearbox, its compositio cocer with matchig algorithm 5-6. Query tables of egie speed characteristics ad fuel cosumptio characteristics 7. Egie speed coversio module, that ca covert the speed uit of rad/s ito r/mi 8. Egie output torque sigal 9. Egie output speed sigal 10. Flywheel momet of iertia; 11. Couplig. Figure 6 Egie model Figure 7 shows the gearbox simulatio model. The costructio of process cotroller model is a prerequisite for simulatio ad aalysis. The study focus o the steady-state characteristics of the tractor before ad after matchig with operatig coditios. There are requiremets for the process O the basis of the above simulatio models, the obtaied biary speed ratio matchig simulatio model of the gearbox-egie system after the cotrol system recostructio is show i Figure Simulatio aalysis of plowig coditio Uder the coditio of plowig, the tractor load is heavy the drivig speed is limited to 5-10 km/h. I the simulatio calculatio, the used mouldboard plow width is 105 cm, the mass is 1140 kg, ad the comprehesive frictio coefficiet betwee the plow ad the soil is set as 0.4. The tractor starts with HM1. The iitial target travel speed is 8 km/h, adjusts the speed to 5 km/h at 200 s, ad adjusts the depth of plowig at 50 s, 100 s, 150 s, 250 s, as show i Table 3. The simulatio lasts for 300 s ad the results are show i Figure 10.

6 May, 2018 Xiao M H, et al. Fuel ecoomy of multiple coditios self-adaptive tractors with hydro-mechaical CVT Vol. 11 No Figure 9 Tractor cotroller model i two-parameter speed match betwee trasmissio ad egie Table 3 Plowig simulatio coditio Time/s Target speed/km h -1 Plowig depth/cm The specific fuel cosumptio of egie ad gearbox-egie system i the HM2 sectio ca be as low as 203 g/(kw h), 238 g/(kw h). Respectively, i the HM1 sectio ca be as low as 214 g/(kw h), 268 g/(kw h). Uder the cotroller s speed ratio adjustmet, these values i the segmet chage a little with the load, the basic law is the greater the load, the better the ecoomy. I additio, the gearbox ecoomy i the HM2 sectio is better tha the HM1 sectio, that is, the higher the segmet, the better the fuel ecoomy. a. Egie specific fuel cosumptio b. System specific fuel cosumptio Figure 10 Simulatio results i two-parameter speed match uder plowig coditio 4.3 Simulatio aalysis of sowig coditio Uder the sowig coditio of the tractor, the load is relatively light, the drivig speed is limited to 6-15 km/h ad the small oil throttle is ofte used. I the simulatio, set the resistace of uit width is 1500 N, sowig rage is 4 m, ad the tractor starts with HM1. Set the iitial target speed is 8 km/h, i the first 50 s, 100 s, the target speed is adjusted to 10 km/h ad 14 km/h, which is show i Table 4. The simulatio lasts for 150 s ad the results are show i Figure 11. Table 4 Sowig simulatio coditio -1 Uit sowig amplitude Time/s Target speed/km h resistace/n

7 108 May, 2018 It J Agric & Biol Eg Ope Access at Vol. 11 No.3 a. Egie specific fuel cosumptio b. System specific fuel cosumptio Figure 11 Simulatio results i two-parameter speed match uder sowig coditio The specific fuel cosumptio of egie ad gearbox-egie system are maitaied at a low level throughout the whole ruig process, i the HM2 sectio beig as low as 226 g/(kw h) ad 296 g/(kw h), i the HM3 sectio beig as low as 207 ad 248 g/(kw h). Uder the cotroller s speed ratio adjustmet, the gearbox fuel ecoomy i the HM3 sectio is better tha the HM2 sectio, that is, the higher the segmet, the better the fuel ecoomy. Whe workig i the field, the situatio is more complicated tha i the bech test. The speed ratio matchig strategy has strog adaptive ability for all kids of complex workig coditios, such as light load for sowig ad heavy load for plowig. The whole machie ecoomy of the "gearbox-egie" system i tractor field operatio ca be realized.the simulatio results show that the speed ratio matchig strategy is more sesitive to load tractio. The greater the tractio force, the better the ecoomy of the speed ratio matchig. It is particularly suitable for the situatios of low speed ad heavy load, such as tractor field operatios uder plowig ad other coditios. Therefore, i the field, the fuel ecoomy uder plowig coditio is better tha that uder sowig coditio. The above process ca be moitored by a smartphoe based applicatio software (APP) amed Precise Moitorig System (PMS). It ca record the farm operatio iformatio icludig the tractor [25]. The results showed that PMS ca realize the basic fuctios such as precise ad real-time moitorig. 5 Coclusios I this study, a speed ratio matchig method to achieve the tractor fuel ecoomy was preseted. Firstly, the stepless speed chage fuctio of HMCVT was realized by simulatio ad experimetal verificatio based o the ewly desiged HMCVT program. Secodly, the study established simulatio models of the egie, HMCVT ad the cotrol system. The, o the basis of the above simulatio models, the biary speed ratio matchig simulatio model of the gearbox-egie system was obtaied. Fially, accordig to the combiatio of the automatic avigatio ad the HMCVT, the fuel ecoomy uder two typical workig coditios of plowig ad sowig were studied. Compared with the curret atioal stadard, the fuel ecoomy of the wheeled tractors with the power of 130 kw is 380 g/(kw h), specific fuel cosumptio is reduced by 21.1%. The combiatio of avigatio ad the ecoomic performace of the multiple coditios self-adaptive tractor with the HMCVT has a very good applicatio prospect i precisio agriculture. Some improvemets ca be expected i the future. For example, for most of the farmig operatios metioed, the avigatio cotrol accuracy of a agricultural vehicle avigatio system ca be improved further. Ackowledgmets The research is fuded partially by the Natioal Key Research ad Developmet Program of Chia (2016YFD ), Sciece ad Techology Foudatio of Outstadig Youg Talets of Najig Agricultural Uiversity (YQ201605), the Fudametal Research Fuds for the Cetral Uiversities fud (KYZ201760). [Refereces] [1] Wag Y K, Che J, Bai Y R. Research o tractor hydraulic mechaical cotiuously variable trasmissio. Trasactios of the CSAE, 2000; 16(2): (i Chiese) [2] Pa W J, Zhu Y D, Jiag Z, Che F Q, Mou Y J. Optimizatio of trasmissio speed ratio based o improved fuel ecoomy. Equipmet Maufacturig Techology, 2017; 4: (i Chiese) [3] Cai W X, Xiao C W, Huag X Y, Qiu Z C, Che K. The shift guidace system based o the best fuel ecoomy. Applicatio of Computer

8 May, 2018 Xiao M H, et al. Fuel ecoomy of multiple coditios self-adaptive tractors with hydro-mechaical CVT Vol. 11 No Systems, 2015; 24(3): (i Chiese) [4] Moitzi G, Wagetristl H, Refeer K, Weigartma H, Piriger G, Boxberger J. Effects of workig depth ad wheel slip o fuel cosumptio of selected tillage implemets. Agricultural Egieerig Iteratioal: The CIGR e-joural, 2014; 16(1): [5] Cutii M, Bisaglia C. Developmet of a dyamometric vehicle to assess the drawbar performace of high-powered agricultural tractors. Joural of Terramechaics, 2016; 65: [6] T, Šmerda, J, Čupera. Tire iflatio ad its ifluece o drawbar characteristics ad performace-eergetic idicators of a tractor test. Joural of Terramechaics, 2010; 47(6): [7] Turker U, Ergul I, Eroglu M C. Eergy efficiecy classificatio of agricultural tractors i Turkey based o OECD tests. Eergy Educatio Sciece ad Techology. Part A: Eergy Sciece ad Research, 2010; 28(2): [8] Godwi R J. A review of the effect of implemet geometry o soil failure ad implemet forces. Soil ad Tillage Research, 2007; 97(2): [9] Adamchuk V, Bulgakov V, Nadykto V. Theoretical research ito the power ad eergy performace of agricultural tractors. Agroomy Research, 2016; 14(5): [10] Kag C F, Ha H Q, Dai L Q, Zou L H. Fuel ecoomy simulatio of automobile ad aalysis of ifluecig factors. CHINA SAE, 2013; 4. (i Chiese) [11] Ji Z. Evaluatio method ad device for fuel ecoomy of automobile. Neusoft Group Co., Ltd, (i Chiese) [12] Zhou M. Research o fuel ecoomy of automatic variable speed vehicle ramp. Beijig Istitute of Techology, (i Chiese) [13] Kumar N, Padey K P. A visual basic program for predictig optimum gear ad throttle positio for best fuel ecoomy for 32 kw tractor. Computers ad Electroics i Agriculture, 2015; 119: [14] Deg Z Y. Research o evaluatio method of automobile fuel ecoomy. Southwest Jiaotog Uiversity, (i Chiese) [15] Lee J W., Kim J S, Kim K U. Computer simulatios to maximise fuel efficiecy ad work performace of agricultural tractors i rotovatig ad ploughig operatios. Biosystems Egieerig, 2016; 142: [16] Nadykto V. Method of determiig agricultural tractor s egie power ratig. Machiery ad Techologies of Agro-Idustry, 2014; 1:7 9. [17] Algirdas J, Vidas D, Gedimias P. Effect of variatios i frot wheels drivig lead o performace of a farm tractor with mechaical frot-wheel-drive. Joural of Terramechaics, 2018; 77: [18] Gao X H. Research o key techology of car fuel ecoomy developmet. Hefei Uiversity of Techology, (i Chiese) [19] Weichai Power Co., Ltd.. 180PS with Tractor Diesel Egie Developmet Test Report (Ecoomic Editio). Weifag: Weichai Power Co., Ltd (i Chiese) [20] Zhu S H. Developmet ad tred of tractor i Germay. Joural of Agricultural Mechaizatio, 2002; 33(1): (i Chiese) [21] Shi J L. Desig of HMCVT for o-road vehicle ad cotrol of variable pump. Najig: Najig Agricultural Uiversity, (i Chiese) [22] Ni X D. Research o trasmissio characteristics of tractor's hydraulic machiery multi-sectio double-row discharge cotiuously variable trasmissio. Najig: Najig Agricultural Uiversity, (i Chiese) [23] Ha X, Kim H J, Jeo C W, Moo H C, Kim J H. Developmet of a low-cost GPS/INS itegrated system for tractor automatic avigatio. It J Agric & Biol Eg, 2017; 10(2): [24] Hu J T, Li T C. Cascaded avigatio cotrol for agricultural vehicles trackig straight paths. It J Agric & Biol Eg, 2014; 7(1): [25] Wu C C, Zhou L, Wag J, Cai Y P. Smartphoe based precise moitorig method for farm operatio. It J Agric & Biol Eg, 2016; 9(3):