Regenerative Shock Absorber in the Vehicle Suspension System

Transcription

1 Regenerative Sock Absorber in te Veicle Suspension System Kireev A.V. 1,a, Kozemyaka N.M. 1,b, Burdugov A.S. 1,c and Klimov A.V. 2,d 1 Scientific and Tecnical Center PRIVOD-N, Novocerkassk City, Krivoslykova St. 4a, Rostov Region, Russian Federation. 2 KAMAZ Innovation centre Ltd, Russian Federation, Moscow. a,b,c,d Orcid: , , , Abstract Te given article as te following aims: to describe te structure of te veicle suspension system capable to regenerate te mecanical vibration energy of te sprung mass into te electrical energy; to present te design of te regenerative sock absorber; to demonstrate te model of te veicle suspension system based on te regenerative sock absorber and designed in MATLAB/Simulink. Te modelling makes it possible to evaluate te power wic te veicle suspension system is capable to recuperate wile running on roads of different surfaces and under various speeds. KEYWORDS: Regenerative sock absorber, ball-screw, permanent magnet syncronous macine, MATLAB model INTRODUCTION According to various estimates, only about 14-30% of te fuel energy in te conventional cars equipped wit te internalcombustion engine is consumed wile driving to overcome te resistance from road friction and air drag [1]. Te rest of te energy is lost to engine, driveline or used to power accessories. One of te factors affecting te car energy efficiency is te losses in te sock absorbers wile travelling along te uneven roadway. In te conventional cars te mecanical energy dissipates in sock absorbers as eat going out to te environment. Te development of te suspension system, equipped wit damping elements capable to regenerate te mecanical vibration energy of te sprung mass wen driving along te uneven roadway, allows us to increase te energy efficiency of te cars equipped wit internalcombustion engines as well as ybrid and electric veicles. Te paper [2] gives te researc results of te units designed for electrical energy regeneration in te suspension of an offroad car travelling along different road surfaces. Te minimal value of regenerative energy is 0,3 kw, wile wit speed and load weigt increasing, it tends to grow. Te paper [3] presents te teoretical performance calculation of energy regeneration in te electromagnetic sock absorber under different speeds and road surfaces, based on te road micro profile analysis. According to te calculation results, te peak recuperative power is 140 W. As te experimental benc tests results [4] of te electromagnetic suspension wit regenerative effect, te peak recuperative power of 1 kw was attained at te sock absorber rod speed of 2 m/s. In tis regard, it is expedient to use te computer modelling and estimate te amount of electric energy capable to be recuperated by te given suspension system wile te veicle is driving under various speeds along te different road surfaces. MATERIALS AND METHODS Te suspension system of te weeled veicle equipped wit te ig-voltage power storage unit includes te following components (figure 1): four regenerative sock absorbers, one per eac weel. Eac sock absorber contains tree-pase syncronous generator wit permanent magnets, indicated as G1 G4 in te sceme; four sock absorber control units, controlling te energy regeneration and generating te required resistance effort depending on te rod speed during te sock absorber compression and rebound; battery carger, generating te carging rate of te energy storage unit. Figure 1: Te structure of te suspension system based on te regenerative sock absorber Figure 2 presents te regenerative sock absorber design for te veicle suspension system. Te screw rod being a part of te ball screw is fixed immovably at te outer tube of te sock absorber; te nut of te ball-screw is fixed at te inner tube wit bearings. During 12390

2 te sock absorber compression and rebound motion, te alternating motion of te rod is converted to te rotation motion of te rotor fixed at te ball screw nut. For tis purpose te internal diameter of te rotor is cosen sligtly bigger tan te crew rod diameter, wic ensures te free moving of te rod inside te rotor. Te rotation of te permanent magnets, fixed at te rotor, induces EMF at te generator stator windings located at te inner tube; tus te mecanical energy of te sock absorber alternating motion is converted into te electrical energy wic can be used for te veicle battery carging. Te tread lead of te screw rod P is 0.04 mm. Te rotor rotation speed V r connects wit linear speed V l of te screw rod wit te following equation: V V l r 60, min -1 P (a) Figure 2: Te regenerative sock absorber design (а) transverse section, (b) longitudinal section 1 inner tube, 2 outer tube, 3 rotor, 4 ball-screw, 5 radial trust bearing, 6 ball bearing, 7 cable gland, 8 stator winding, 9 stator, 10 mounting bus, 11 ball bearing, 12 magnets (b) Tree-pase winding is laid into te core grooves according to te star sceme, wen eac ray of te star consists of eigt series-connected coils. Te alternating tree-pase voltage goes from te generator to te sock absorber control unit, wic is te boost converter, and it is converted to te DC voltage tere. To create te required resistance effort of te sock absorber, te sock absorber control unit regulates te generator electrical load depending on te rod moving direction and te rod speed. To create te asymmetric response (i.e. different efforts during rebounding and compressing) te sock absorber control unit determines te rod moving direction using te testing metod 12391

3 of te generator pase sequence wile te speed is calculated from te frequency of te generated voltage. It allows us to reject te sensors of corresponding values. Eac generator G1 G4 is controlled independently from eac oter. Outputs of te sock absorber control units are joined and connected to te battery carger input. Te battery carger is also designed as te boost converter, te load of wic is te energy storage unit (a traction battery) wit nominal voltage 650 V. Te electrical energy, generating by four sock absorbers, carges te input capacitance of te battery carger, te control system of wic regulates te performance in te way tat te voltage of te input capacitance remains at te level of 400 V. Te output voltage of te unit can be witin V depending on te state of te energy storage unit; at te same time te battery carge control system sould also control te carging rate. Te sock absorber control units and battery carger are powered from te veicle DC network 12 V or 24 V. To estimate te value of regenerating electric energy, wic can be recuperated by te suspension system wile weeled veicle travelling, we ave designed te model MATLAB/Simulink using te SimScape toolbox (fig. 3). In order to simplify te calculation and reduce te processing time, one regenerative sock absorber wit te corresponding control unit and battery carger ave been included into te model. Te input data for te model is te data array getting during te rod speed measurement of te common ydraulic sock absorbers wile te freigt truck running along te different road covering and under various speed; te frigt truck was loaded wit 7900kg, ad 4x2 axle arrangement and travelled wit and witout 36100kg trailer-truck [5]. Te processing of te rod speeds for eac weel was performed separately for eac running, and ten te regenerating energy of eac freigt truck sock absorber was summed. According to te calculation performed for te sock absorber design, te parameters of te Permanent magnet syncronous macine unit are te following: stator pase resistance is 1.2 om, armature inductance is 5.65 mh, voltage constant is V_peak L-L/krpm, pole pairs are 10. Figure 3: Te model of te veicle suspension system wit electrical energy regeneration RESULTS AND DISCUSSION Figure 4 sows te example of te calculation results performed in MATLAB model. Te examples demonstrate two capture samples of te sock absorber rod speed wile moving te freigt truck witout te trailer-truck along te aspalt road under te speed of 70 and along te cobblestone road under te speed of 60. Te graps sow te instantaneous recuperated power and total recuperated energy. Interestingly tat te recuperated energy wen moving along te cobblestone road is tens of times iger tan te energy recuperating during te aspalt running; terefore, te quality of te roadway ave te great impact on te suspension system ability to regenerate te energy

4 (a) (b) Figure 4: Te sock absorber rod speed, instantaneous recuperated power and total recuperated energy of te freigt truck suspension system (a) aspalt road, 70 ; (b) cobblestone road, 60 Table 1 demonstrates te processing result of te experimental data of te freigt truck long runs performed in te developed model. We calculated te total recuperated energy of te freigt truck suspension system wen moving wit and witout te trailer-truck along te aspalt road at te distance of 1.67 km and along te cobblestone road at te distance of 0.83 km under te various speeds. Based on tese results te average power of te set consisting of four sock absorbers as been calculated. Table 1: Te average power of te set consisting of four sock absorbers Power, W Aspalt road Cobblestone road Freigt truck Freigt truck wit te trailer Te calculation results analysis proves tat te recuperated power of te designed suspension system for te truck wen driving along te aspalt road is negligible regardless to te running speed and is comparable to te power wic sock absorber control units and battery carger are going to consume. Muc more significant is te recuperation wen driving on a cobblestone road, even at low speeds. Tis determines te scope of te proposed sock absorber wic is te cargo veicles, moving mainly along unsurfaced roads and quarries. CONCLUSION Te model designed makes it possible to evaluate te energy and power, regenerating by te veicle suspension system, based on te rods speeds recording data of te sock absorbers applying in commercially available or prospective veicles. Tis allows us to conclude tat it is advisable to use recuperation in te suspension of a specific veicle. Te calculated data obtained wit te elp of te model simplifies te estimation of te payback period, life cycle, electrical parameters of te regenerative sock absorber control unit. ACKNOWLEDGEMENTS Te presented work as been developed wit support of Russian Ministry of Education, grant RFMEFI57915X

5 REFERENCES [1] Energy Efficiency & Renewable Energy. [Online]. Available: ttp:// [2] Рosmetyev, V.I., M.V. Drapalyuk, V.A. Zelikov, Estimation of efficiency of application of system recovery of energy in car suspender. Proceedings of te Kuban State Agrarian University, No. 76(02). [3] Siczek, K, M. Kucar, Researces on te amount of recuperated energy by electromagnetic sock absorber in small car. Journal of KONES Powertrain and Transport, Vol. 20, No. 3, pp: [4] Hyniova, K, Usage of one-quarter-car active suspension test stand for experimental verification. WSEAS Transactions on Applied and Teoretical Mecanics, Vol.12, pp: [5] Kireev, A.V., N.M. Kozemyaka, A.S. Burdugov, S.V. Nazarenko and A.V. Klimov, Review on electromagnetic energy-regenerative sock absorbers. Journal of Engineering and Applied Sciences, Vol. 11, pp: