• <tr id="yyy80"></tr>
  • <sup id="yyy80"></sup>
  • <tfoot id="yyy80"><noscript id="yyy80"></noscript></tfoot>
  • 99热精品在线国产_美女午夜性视频免费_国产精品国产高清国产av_av欧美777_自拍偷自拍亚洲精品老妇_亚洲熟女精品中文字幕_www日本黄色视频网_国产精品野战在线观看 ?

    Sliding mode control design for oblique wing aircraft in wing skewing process

    2019-02-27 08:59:06TingYUEZijinXULixinWANGTongWANG
    CHINESE JOURNAL OF AERONAUTICS 2019年2期
    關鍵詞:信息

    Ting YUE,Zijin XU,Lixin WANG,*,Tong WANG

    aSchool of Aeronautic Science and Engineering,Beihang University,Beijing 100083,China

    bChina Ship Development and Design Center,Wuhan 430064,China

    Abstract When the wing of Oblique Wing Aircraft(OWA)is skewed,the center of gravity,inertia and aerodynamic characteristics of the aircraft all significantly change,causing an undesirable flight dynamic response,affecting the flying qualities,and even endangering the flight safety.In this study,the dynamic response of an OWA in the wing skewing process is simulated,showing that the three axis movements of the OWA are highly coupled and present nonlinear characteristics during the wing skewing.As the roll control efficiency of the aileron decreases due to the shortened control arm in an oblique configuration,the all-moving horizontal tail is used for additional roll and the control allocation is performed based on minimum control energy.Given the properties of pitchroll-yaw coupling and control input and state coupling,and the difficulty of establishing an accurate aerodynamic model in the wing skewing process due to unsteady aerodynamic force,a multi-loop sliding mode controller is formulated by the time-scale separation method.The closed-loop simulation results show that the asymmetric aerodynamics can be balanced and that the velocity and altitude of the aircraft maintain stable,which means that a smooth transition is obtained during the OWA's wing skewing.

    KEYWORDS Decoupling;Dynamic response;Oblique wing aircraft;Sliding mode control;Wing skewing process

    1.Introduction

    Oblique Wing Aircraft(OWA)can rotate the wing at different flight velocities to form various wing sweep configurations.Representing a simplified minimum drag solution in supersonic flow,the oblique elliptic wing can achieve efficient flight under subsonic cruise/loiter conditions while providing excellent supersonic dash/cruise capability.1,2Therefore,OWA can adapt to multi-mission flight with extended flight envelope,and demonstrate higher combat effectiveness than conventional fixed-wing aircraft.

    A significant amount of early theoretical work was conducted by Jones starting from the 1950s.3In the past decades,a number of aircrafts were flown to prove the feasibility of flight control of OWA,including small gliders,small remotely piloted aircraft and the manned AD-1 aircraft flown by NASA.4-8Numerous conceptual design studies and research papers have addressed oblique wing-body-tail or oblique flying wing designs,and a number of wind tunnel tests and flight tests have been performed on both oblique wing and oblique flying wing designs.9-17Recently,there has been renewed interest in developing OWA due to its aerodynamic and structural advantages.

    However,a variety of technical difficulties associated with the oblique wing configuration have prevented its application to operational aircraft.A critical technical challenge of OWA arises from its nonlinear and strongly coupled aerodynamic characteristics,and the inertial couplings further complicate the flight dynamics of such aircraft. These complicated characteristics are shown during the wing skewing of OWA,when a relative movement occurs between the wing and the fuselage.The aircraft in various configurations can be described as a time-varying dynamic system.Wing skewing largely changes the aircraft's configuration parameters,including the moment of inertia,the location of the center of gravity,etc.It not only causes changes of lift,drag and pitching moment,but also generates side force,and rolling and yawing moments.This results in the aircraft's highly coupled threeaxis movement and presents strong nonlinearity.In addition,wing skewing causes longitudinal and lateral couplings of aileron control,and lateral control inefficiency of the aileron at a large angle of the oblique wing.As a result,OWA will have an undesirable dynamic response in the presence of wing skews,and the flying qualities and flight safety will deteriorate.It is thus necessary to investigate the flight dynamic characteristics of OWA during wing skewing and design the flight control law to ensure a smooth transition between different configurations.

    The wing skewing process of OWA is similar to that of variable-sweep wing aircraft and morphing aircraft.Several studies have been carried out on the flight dynamic modelling and control of variable-sweep wing aircraft and morphing aircraft in configuration variations.18-23However,unlike the aircraft designed in a symmetric configuration,OWA is characterized by the asymmetry configuration with strong three-axis aerodynamic and inertial couplings,resulting in a significant variation in three-axis motion parameters during wing skewing.Currently,there have been a number of studies mainly focusing on the analysis of flight dynamic characteristics24-26and flight control design of OWA in static configurations(wing- fixed configurations at different oblique angles).27-32However,the existing literature does not consider the influence of the wing skewing process on aircraft's dynamic characteristics;additionally,there is lack of published literature about dynamic characteristics of and flight control design for the process of wing skewing.

    Due to the inertial and pitch-yaw-roll aerodynamic couplings in the wing skewing process,OWA is a non-linear time-varying system.This causes a difficulty in modeling precisely the aerodynamics of wing skewing which has uncertain dynamic behaviors.In addition,due to the inertial and aerodynamic cross-couplings,it is difficult for conventional control methods such as proportional-Integral-Derivative(PID)control to obtain acceptable control performance.A feasible approach for flight control design is sliding mode control theory,which can guarantee the dynamic qualities of the sliding mode motion and approaching motions by designing the sliding mode function and approaching rate,respectively.33,34

    In this study,OWA is regarded as a rigid body system composed of the fuselage and rotating wing,and a time-varying and nonlinear dynamic model is built in order to examine the flight dynamic characteristics of OWA in the wing skewing process.The dynamic responses are numerically simulated and analyzed.According to the highly pitch-roll-yaw coupling,control input and state coupling,and nonlinear properties of OWA,a multi-loop sliding mode controller is designed based on the time-scale separation method.The all-moving horizontal tail is used for roll control due to the insufficient control effect of the aileron,and the control allocation of the control surfaces is performed based on minimum control energy.The simulation results show that the controller can ensure the good dynamic characteristics of OWA during wing skewing.The work introduced in this paper can provide a theoretical reference for flight control design for OWA.

    2.Dynamic modeling and analysis

    2.1.Layout and aerodynamic characteristics of OWA

    The OWA investigated in this study is presented in Fig.1.The oblique wing is designed to rotate from 0°to 60°with the right wing forward.

    When the wing is skewed,the configuration parameters of the OWA change significantly,which mainly include the center of gravity position and the moment of inertia.Since the rotation axis of the wing is in front of the wing gravity center and parallel to thez-axis in the body axes,the aircraft's gravity center shifts forward to the right when the wing is skewed,while the gravity center position along thez-axis remains unchanged.Meanwhile,the inertia moment and product of inertia also change significantly.As the symmetry of the conventional layout is destroyed,the cross inertial productsIxyandIyzappear.The inertia coupling is strong between the longitudinal and lateral axes,which obviously affects the flight dynamic characteristics of the OWA.32

    The asymmetric layout formed by the skewed wing also has a great influence on aerodynamic characteristics,which are stated as follows.32The drag gradually decreases with the increase of the skew angle Λ.Since the effective wing span reduces after the wing is oblique,the lift decreases.In addition,the asymmetric wing layout generates side force,which is rather large and cannot be ignored.The oblique wing generates not only additional nose-down pitching moment,but also rolling moment and yawing moment.The rolling moment sinks the front wing and the yawing moment makes the aircraft rotate to the right.

    Fig.1 Layout of the oblique wing aircraft.

    After the wing is oblique,the ailerons are arranged back and forth.When the ailerons are deflected,the difference in lift will generate additional pitching moment.32This should be considered in designing flight control law for the wing skewing process.In addition,the control arm of the aileron is shortened after the wing is oblique,which gradually decreases the roll control efficiency of the aileron with the increase of the wing skew angle.This may result in insufficient roll control ability of the ailerons.Therefore,it is necessary to use the all moving horizontal tail for additional roll control of the OWA in the large skew angled configuration.27

    2.2.Dynamic modeling

    During the oblique wing skewing,the OWA's gravity center keeps changing.In this paper,the origin of the body axes is located at the center of gravity of the OWA at 0°skew angle.According to the momentum theorem and the theorem of moment of momentum for any moving point,18,35we get the nonlinear dynamic equations of the OWA in the wing skewing process in a scalar form as below:

    where[X,Y,Z]is the total force on the aircraft,[L,M,N]the total moment relative to the origin of the body axes,mthe mass of the aircraft,[u,v,w]the flight velocity,[p,q,r]the angular velocity in the body axes relative to the inertial axes,[Sx,Sy,Sz]the static moment of aircraft,[S1x,S1y,S1z]the static moments of the wing,mthe mass of the wing,Ithe rotational inertia,and[ω1x, ω1y, ω1z]the projections of the angular velocity of the wing in the body axes.It can be seen from Eqs.(1)and(2)that,unlike the dynamic equations of conventional fixed-wing aircraft,there are additional terms caused by the center of gravity position shift and wing skew rate.

    In the variable-sweep process of swept-wing aircraft and the wing-folding process of morphing aircraft,when the changing rate of configurations is slow,the influence of unsteady aerodynamic characteristics of the aircraft is small.18,21,22Analogously,when the angular velocity of the OWA's wing skew is comparatively small,the quasi-steady assumption can be used to simplify the calculation of aerodynamic force during the wing skewing process.It is considered that the aerodynamic force of the whole aircraft depends on the static configuration and the flight status of the aircraft at that time.In this study,we just investigate the case in which the angular velocity of the OWA's wing skew is comparatively slow,and in which the aerodynamic force is simplified using the quasi-steady assumption.The aerodynamic uncertainty caused by simplification is solved by robust sliding mode control design.Therefore,here we simplify that the aerodynamic model during the wing skewing is the same with the static configuration.32

    When the OWA is in an asymmetric configuration,the pitching motion will generate roll and yaw motions which will then generate pitching motion.Moreover,the deflection of the aileron will generate pitching moment.The aerodynamic crosscouplings are dependent on the wing skew angle and the angle of attack.As a result,the nonlinear equation of motion can be expressed as

    where f is a nonlinear time-varying function about x and u.The changes of the state variables affect the efficiency of the control input,and the control input can lead to changes of the state variables,i.e.,coupling exists between x and u and cannot be overlooked.This is the main difference of the six degrees of freedom nonlinear model with that of conventional aircraft.

    2.3.Analysis of dynamic characteristics

    The flight dynamics of the OWA in the wing skewing process without control is mathematically simulated.The aircraft's CG position of the straight wing configuration is selected as the origin of the body axes.The wing skewing process and returning to straight wing process are simulated separately.The initial condition is a straight and level flight atH=4000 m andMa=0.4.The dynamic responses are presented in Figs.2 and 3,where γ,φ,andVare climb angle,roll angle and velocity respectively.

    It can be seen from Fig.2 that the initial responses of the aircraft are mainly the changes of the three-axis angular velocities and attitudes when the wing is skewed.This is mainly caused by the asymmetric aerodynamic layout,resulting in a nose down pitching moment and positive rolling and yawing moments.The rolling moment sinks the front wing and the yawing moment makes the aircraft rotate to the right.As the skew angle continues to increase to 30°,the asymmetric rolling moment still exists.Then the roll angle increases rapidly and the lift direction keeps tilting.Meanwhile,the lift coefficient decreases with the increase of the skewing angle,so that the lift cannot balance the gravity of the aircraft.Therefore,the aircraft dives with acceleration and cannot reach a new steady state.

    Fig.2 Dynamic responses in the wing skewing process.

    During the changes of configurations,the attitude,altitude and speed of the OWA are all obviously changed.Therefore,a flight control law should be designed to ensure the flight safety and flying qualities of the aircraft in the dynamic process.

    3.Flight control law design based on sliding mode control method

    In the wing skewing process,the three-axis movements of the OWA are highly coupled and strongly nonlinear,and it is thus difficult to establish an accurate aerodynamic model.This leads to a certain error between the simulation results and the real flight response,meaning that there exists uncertainty in the motion model of the aircraft.In addition,the range of the motion parameters is large,which requires the flight control system to be more robust.Since the sliding mode control method can ensure the dynamic quality through the design of the sliding mode function and the approach rate,the designed controller can adapt to the parameter changes of the OWA during the wing skewing.The sliding mode controller has strong robustness and can obtain precise control effect,more suitable for the OWA with a large range of parameter variations,and with time-varying and nonlinear characteristics.Therefore,the flight control law using sliding mode control method is designed in this study.The control objective is to keep the altitude and velocity of the OWA constant during the wing skewing,so that a smooth transition of the configuration changes can be achieved.

    Fig.3 Dynamic responses during the returning to the straight wing.

    3.1.Flight control system design based on sliding mode control

    If a nonlinear system˙x=f( x,u,t)can be transformed to an affine system˙x=f( x,t)+g( x,t)u,the sliding mode control can be applied conveniently.However,the OWA's dynamic equations of motion during the wing skewing exhibit inertia and aerodynamic cross couplings,and cannot be directly transformed to the affine form.According to the characteristics of the aircraft motions,we propose that the OWA's variables of movement are divided into fast and slow variables by using the time-scale separation method.Then the complicated nonlinear equations can be simplified to an inner-loop and an outer-loop affine systems,and the sliding mode control design can be easily applied to the design of the inner-loop and outer loop sliding mode controllers.

    The sliding mode flight control system introduced in this paper mainly includes five modules:the modules of control command generation,outer-loop control law,inner-loop control law,control surface allocation,and automatic throttle.The inner and the outer loops are separated by time-scale separation method for the aircraft motions.The control structure is shown in Fig.4.

    Fig.4 Flight control structure.

    The function of each module is introduced as follows:

    (1)The control command generation module generates control commands to the outer-loop control law module and the automatic throttle module based on the states of the aircraft.In order to ensure that the aircraft's altitude and speed remain constant without sideslip,the roll angle is used to generate force to balance the side force generated by the asymmetric configuration.The output control commands are formulated as

    where ΔV, αc, βcand μcare the output command of speed,angle of attack,side slip angle and roll angle in the speed axis,respectively.HcandVcare the target altitude and speed,respectively.KΔH,K˙HandK˙yare the gains corresponding to the altitude error ΔH,the altitude varying rateand the yaw rate,tuned to be 2 rad/m,-0.5 rad s/m and-6 rad s/m according to the control performance,respectively.

    本文中我們采用哈希算法,主要的過程為:發(fā)送方采用單向哈希函數(shù)對消息進行計算,得到摘要并發(fā)送消息和摘要。接收方將接收到的消息,按同樣方式進行哈希函數(shù)計算,并將新得出的結果與發(fā)送方的原摘要結果進行比對。如結果一致,說明消息完整。在本系統(tǒng)中,摘要信息的不可變,保證了需要存證信息的完整性和真實性。將需要存證的電子數(shù)據(jù)放在區(qū)塊鏈中,避免數(shù)據(jù)被惡意篡改。

    (2)The outer-loop control model generates the input command [pc,qc,rc]Tfor the inner-loop model based on the control reference[αc,βc,μc]T.According to the time-scale separation method for the state variables,the dynamic responses of the fast variables of the inner-loop are considered to have reached steady states and are neglected in the outer-loop design.Thus,the inner and outer-loop control laws can be designed separately.The differential equation can be expressed as

    where xs=is the 3 × 3 matrix in Eq.(5),us(t)=[p,q,r]T,ys(t)is the output.

    For a system such as Eq.(6),according to the sliding mode control theory,36the sliding mode surface can be designed as

    where the values of the sliding surface control parameterscis(i=1,2,3)should makeHurwitz stable.The system can reach the sliding mode surface within a limited time and the error tends to be zero when the control law takes the following form37,38:

    In order to suppress the vibration of the system,the signfunction sgn of the control law is replaced by the following saturation function

    where ε is a small positive number.According to the control effect,the parameters are tuned as below:Rs=diag{2,2,2},Γs=diag{0.1,0.1,0.1},and ε=0.1.

    (3)The inner loop calculates the required three-axis control moments to track the command [pc,qc,rc]T.The rotational dynamics Eq.(2)can be rewritten as

    Similar to the nonlinear MIMO system of the outer loop,Mccan also be obtained by using the control law of Eq.(8).Here and∑f=also replaced by a saturation function wherea1=a2=a3=2/3,and ε=0.05.

    (4)The control allocation module calculates the required deflections of the control surfaces based on the demand of three-axis control moment Mc.Since the roll control efficiency of the OWA's aileron is low in the large skew angled configuration,the all-moving horizontal tails are used to assist roll control.27The control surface allocation can be expressed as

    where G is the matrix of the control coefficient,and u= [δa,δr,δeL,δeR],δa,δr,δeL,δeRare deflections of the aileron,rudder,left elevator and right elevator,gij(i=p,q,randj= δa,δr,δeL,δeR) are the three-axis moment control efficiencies.

    In order to avoid the full or extremely small deflection of a certain control surface,we use Δ =]to weigh the allocation.Then Eq.(11)can be rewritten as

    where GΔ=GΔ,and^u=[δa/δamax,δr/δrmax,δeL/δeLmax,δeR/δeRmax]T.The control inputucan be obtained by a pseudoinverse of Eq.(12),an expenditure of minimum control energy,39and can be expressed as

    (5)Since the drag and flight velocity of the OWA both change significantly in the wing skewing process,the throttle is used to control the speed of the aircraft.Designed by the traditional PID control method,40the automatic throttle control law is expressed as

    Fig.5 Closed-loop system responses(H=4 km and Ma=0.4).

    wherek1,k2,andk3are the gains of PID,and the parameters are tuned ask1=-6 s/m,k2=-5 m-1andk3=-1.5 s2/m.

    3.2.Closed-loop simulation and analysis

    The sliding mode control law is verified by closed-loop simulations for the wing skewing process and the process of wing returning to the straight position.The initial flight conditions areH=4 km andMa=0.4.The dynamic responses of the parameters are shown in Fig.5.

    The closed-loop simulation results for the wing skewing process are shown in Fig.5(a).It can be seen that since the lift coefficient of the aircraft gradually decreases with the increase of the skewing angle,the angle of attack gradually increases to achieve the balance of the longitudinal force.The sideslip angle is maintained as 0°,which is consistent with the target command.The aircraft rolls to the left and the component of gravity is used to balance the asymmetric side force;the aircraft eventually maintains a certain roll angle.In the entire process,the speed and altitude of the aircraft basically remain unchanged.We can see that the three-axis control surfaces deflect collaboratively to balance the asymmetric aerodynamic moments and that the throttle is decreased to balance the reduced drag.The all-moving horizontal tail participates in roll control and involves in the control allocation based on minimal control energy,and the deflections of the control surfaces and the throttle are smooth.

    The closed-loop simulation results for the process of wing returning to the straight position are shown in Fig.5(b).It can be seen that the attitude of the aircraft changes exactly in the opposite direction of the wing skewing process.The lift coefficient increases,the lateral force decreases to zero,and the angle of attack decreases.Moreover,the roll angle for balancing the side force returns to zero,while the sideslip angle remains zero.After returning to the symmetrical configuration of the straight wing,the asymmetric moment disappears and the drag increases.As a result,the lateral control surfaces(rudder,ailerons,and differential horizontal tail)decrease to zero and the throttle increases accordingly.During the whole process,the flight velocity and altitude of the aircraft basically remain unchanged.It can be seen that the sliding mode flight control law can fully guarantee the OWA flight at the required altitude and speed during the processes of wing skewing and returning to the straight position.

    Fig.6 Closed-loop system responses(H=5 km and Ma=0.5).

    To validate its robustness in the presence of the oblique wing,the sliding mode flight controller is applied to control the OWA in another flight state.Fig.6 presents the closedloop dynamic responses of the OWA during both the wing skewing and the returning to the straight wing atH=5 km andMa=0.5;the responses are controlled by the sliding mode flight controller designed for the state ofH=4 km andMa=0.4.We can see that the flight controller can still ensure that the altitude and speed in the wing skewing process are almost unchanged.This means that the sliding mode controller designed in this study has good robustness.

    4.Conclusions

    (1)The three-axis motions of the OWA are significantly coupled and highly nonlinear in the wing skewing process.The initial dynamic responses of the aircraft in the processes of wing skewing and wing returning to the straight position are mainly the changes of threeaxis angular velocities and attitudes.With the rapid increase of the roll angle,the lift direction of the aircraft continuously changes,thus being unable to balance the gravity of the aircraft.The aircraft continues to dive with acceleration in the two processes mentioned above,and cannot reach a new balance state.

    (2)The moment arm of the aileron is shortened when the wing is skewed,which leads to an insufficient rolling control effectiveness.Therefore,the all-moving horizontal tail is used for assistant roll control.According to the three-axis coupling characteristics of aileron control,the control surfaces are allocated based on minimum control energy,achieving an accurate control effect.

    (3)According to the characteristics of pitch-roll-yaw coupling,control input and state coupling,and difficulty to accurately establish the aerodynamic model,a multi-loop sliding mode flight controller is designed by the time-scale separation method for the OWA to ensure the smooth transition during the wing skewing.The simulation results show that the robust sliding mode flight controller can smoothly adjust the attitude of the OWA to balance the asymmetric aerodynamic forces generated in the processes of wing skewing and returning.In addition,the speed and altitude of the aircraft can be kept constant.

    Acknowledgement

    This work was supported by the National Natural Science Foundation of China(No.11402010).

    猜你喜歡
    信息
    訂閱信息
    中華手工(2017年2期)2017-06-06 23:00:31
    展會信息
    中外會展(2014年4期)2014-11-27 07:46:46
    信息超市
    展會信息
    展會信息
    展會信息
    展會信息
    展會信息
    信息
    健康信息
    祝您健康(1987年3期)1987-12-30 09:52:32
    亚洲av中文字字幕乱码综合| 欧美成人午夜免费资源| 男女国产视频网站| 亚洲av.av天堂| 国产乱人视频| 你懂的网址亚洲精品在线观看| 亚洲色图av天堂| 国产欧美日韩精品一区二区| 欧美成人午夜免费资源| 欧美日韩亚洲高清精品| 欧美丝袜亚洲另类| 高清欧美精品videossex| 青春草亚洲视频在线观看| 久久久精品94久久精品| 亚洲自拍偷在线| 国产永久视频网站| 日本熟妇午夜| 亚洲性久久影院| 国产伦一二天堂av在线观看| 欧美一级a爱片免费观看看| 国产v大片淫在线免费观看| 午夜激情欧美在线| 国产亚洲av嫩草精品影院| 亚洲va在线va天堂va国产| 国产黄色小视频在线观看| 在线观看美女被高潮喷水网站| 国产精品三级大全| 久久久久久久午夜电影| 麻豆国产97在线/欧美| 国产精品爽爽va在线观看网站| 最近最新中文字幕免费大全7| 精品一区二区免费观看| 久久99热这里只有精品18| 热99在线观看视频| 黄片wwwwww| 99久久精品热视频| av国产免费在线观看| 人人妻人人澡欧美一区二区| 亚洲国产精品sss在线观看| 人体艺术视频欧美日本| 国内精品一区二区在线观看| www.av在线官网国产| 欧美激情国产日韩精品一区| a级一级毛片免费在线观看| 成人亚洲精品av一区二区| 乱系列少妇在线播放| 一二三四中文在线观看免费高清| 女人十人毛片免费观看3o分钟| 日本免费a在线| 国产高清有码在线观看视频| 超碰av人人做人人爽久久| 成人特级av手机在线观看| 久久综合国产亚洲精品| 久久6这里有精品| 内地一区二区视频在线| 日本av手机在线免费观看| 狂野欧美激情性xxxx在线观看| 亚洲熟妇中文字幕五十中出| 日韩大片免费观看网站| www.色视频.com| 搡女人真爽免费视频火全软件| 菩萨蛮人人尽说江南好唐韦庄| 国产一区二区在线观看日韩| 91aial.com中文字幕在线观看| 我的女老师完整版在线观看| 亚洲av.av天堂| 久久久久久久午夜电影| 一个人免费在线观看电影| 国产综合精华液| 久久午夜福利片| 高清欧美精品videossex| 水蜜桃什么品种好| 国产精品蜜桃在线观看| 日韩国内少妇激情av| 哪个播放器可以免费观看大片| 一区二区三区四区激情视频| 女的被弄到高潮叫床怎么办| 在线天堂最新版资源| 高清日韩中文字幕在线| 国产人妻一区二区三区在| 成人综合一区亚洲| 2022亚洲国产成人精品| 久久99热这里只频精品6学生| 超碰97精品在线观看| 特级一级黄色大片| 亚洲美女视频黄频| 国产成人a∨麻豆精品| 亚洲va在线va天堂va国产| 亚洲内射少妇av| 网址你懂的国产日韩在线| 久久久久久久久中文| 插逼视频在线观看| 人人妻人人看人人澡| 欧美不卡视频在线免费观看| 汤姆久久久久久久影院中文字幕 | 美女大奶头视频| 最近最新中文字幕免费大全7| 一级毛片电影观看| 亚洲国产最新在线播放| 国产一级毛片在线| 国产片特级美女逼逼视频| 非洲黑人性xxxx精品又粗又长| 亚洲精品中文字幕在线视频 | 国产 一区 欧美 日韩| 久久这里有精品视频免费| 亚洲性久久影院| 全区人妻精品视频| 日韩av在线免费看完整版不卡| av免费观看日本| 免费不卡的大黄色大毛片视频在线观看 | 国产精品爽爽va在线观看网站| 三级国产精品片| 青春草视频在线免费观看| 我的老师免费观看完整版| 色哟哟·www| 非洲黑人性xxxx精品又粗又长| 高清视频免费观看一区二区 | 又黄又爽又刺激的免费视频.| 欧美三级亚洲精品| 草草在线视频免费看| 一级片'在线观看视频| 男女视频在线观看网站免费| 国产av国产精品国产| 美女内射精品一级片tv| 久久精品夜色国产| 免费黄网站久久成人精品| 中文字幕人妻熟人妻熟丝袜美| 国产成人一区二区在线| 国产白丝娇喘喷水9色精品| 国产亚洲5aaaaa淫片| 高清日韩中文字幕在线| 中国国产av一级| 国产亚洲av嫩草精品影院| 亚洲一区高清亚洲精品| 一个人看视频在线观看www免费| 日韩av在线免费看完整版不卡| 国产一区二区三区av在线| 精华霜和精华液先用哪个| 美女大奶头视频| 久久久久久久午夜电影| 69人妻影院| 能在线免费看毛片的网站| 成年免费大片在线观看| 日韩一区二区视频免费看| 免费高清在线观看视频在线观看| 亚洲精品影视一区二区三区av| 在线观看人妻少妇| 国产黄片美女视频| 国产免费福利视频在线观看| 亚洲美女视频黄频| 国产综合精华液| 日韩亚洲欧美综合| 特大巨黑吊av在线直播| av在线亚洲专区| 成人毛片60女人毛片免费| 美女黄网站色视频| 日韩三级伦理在线观看| 91精品伊人久久大香线蕉| 免费看av在线观看网站| 日韩电影二区| 伦理电影大哥的女人| 亚洲精品aⅴ在线观看| 亚洲精品自拍成人| 欧美日韩在线观看h| 久久久精品欧美日韩精品| 观看美女的网站| 久久97久久精品| 老司机影院成人| 午夜精品国产一区二区电影 | 少妇人妻精品综合一区二区| 亚洲av成人精品一区久久| 搞女人的毛片| 女人被狂操c到高潮| 十八禁国产超污无遮挡网站| 日本熟妇午夜| 哪个播放器可以免费观看大片| 激情五月婷婷亚洲| 国产精品伦人一区二区| 国内精品美女久久久久久| 偷拍熟女少妇极品色| 伊人久久国产一区二区| 蜜臀久久99精品久久宅男| 一二三四中文在线观看免费高清| 赤兔流量卡办理| 久久99蜜桃精品久久| 亚洲精品影视一区二区三区av| 成人一区二区视频在线观看| 日韩不卡一区二区三区视频在线| 国产精品嫩草影院av在线观看| 久久久久免费精品人妻一区二区| 日韩精品有码人妻一区| av在线天堂中文字幕| 国产片特级美女逼逼视频| 熟妇人妻不卡中文字幕| 久久精品熟女亚洲av麻豆精品 | 七月丁香在线播放| 欧美xxxx黑人xx丫x性爽| 国产v大片淫在线免费观看| 国产色婷婷99| 大又大粗又爽又黄少妇毛片口| 极品少妇高潮喷水抽搐| 白带黄色成豆腐渣| 欧美bdsm另类| 国产视频内射| av在线蜜桃| 久久精品久久精品一区二区三区| 亚洲av成人精品一区久久| 国产午夜精品久久久久久一区二区三区| 一区二区三区免费毛片| 中文资源天堂在线| 麻豆国产97在线/欧美| 亚洲精品国产av蜜桃| 1000部很黄的大片| 午夜福利视频精品| 亚洲精华国产精华液的使用体验| 亚洲自拍偷在线| 91在线精品国自产拍蜜月| 青春草国产在线视频| 欧美变态另类bdsm刘玥| 肉色欧美久久久久久久蜜桃 | 国产av不卡久久| 乱系列少妇在线播放| 国产精品一区二区三区四区免费观看| 国产视频首页在线观看| 日本一本二区三区精品| 日本色播在线视频| 久久精品国产亚洲网站| 成人毛片a级毛片在线播放| 国产av国产精品国产| 可以在线观看毛片的网站| 欧美日韩精品成人综合77777| 亚洲欧美中文字幕日韩二区| 国内精品一区二区在线观看| 深爱激情五月婷婷| av专区在线播放| 日韩精品有码人妻一区| 成人二区视频| 国产极品天堂在线| 国产精品嫩草影院av在线观看| 人妻制服诱惑在线中文字幕| 夫妻午夜视频| 亚洲在线观看片| 少妇丰满av| 亚洲精品成人av观看孕妇| 国产黄片美女视频| 中国国产av一级| 成人美女网站在线观看视频| 亚洲av男天堂| 日本三级黄在线观看| av在线观看视频网站免费| 国产在视频线精品| 成年版毛片免费区| 最近中文字幕高清免费大全6| 欧美潮喷喷水| 国产一区亚洲一区在线观看| 亚洲图色成人| 婷婷色综合大香蕉| 麻豆av噜噜一区二区三区| 午夜福利在线观看免费完整高清在| 日韩成人av中文字幕在线观看| 日韩欧美国产在线观看| av在线蜜桃| 少妇的逼好多水| 三级毛片av免费| 大香蕉久久网| 国产综合精华液| 成人欧美大片| 国产成年人精品一区二区| 特大巨黑吊av在线直播| 精品人妻视频免费看| 精品欧美国产一区二区三| 成年女人在线观看亚洲视频 | 尾随美女入室| 国产熟女欧美一区二区| av免费在线看不卡| av国产久精品久网站免费入址| 亚洲天堂国产精品一区在线| 寂寞人妻少妇视频99o| 深爱激情五月婷婷| 亚洲精华国产精华液的使用体验| 久久久久久国产a免费观看| 国产 一区 欧美 日韩| 黄片wwwwww| 麻豆精品久久久久久蜜桃| 亚洲欧美精品自产自拍| 午夜福利视频1000在线观看| 熟女电影av网| 插阴视频在线观看视频| 亚洲经典国产精华液单| 在线观看免费高清a一片| 亚洲欧美成人精品一区二区| 91久久精品国产一区二区三区| 男女那种视频在线观看| 国产精品一及| 中文在线观看免费www的网站| 黄片wwwwww| 国产人妻一区二区三区在| 在线播放无遮挡| av免费观看日本| 国产成人a∨麻豆精品| 日韩欧美国产在线观看| 久久热精品热| 国产精品日韩av在线免费观看| 国产精品久久久久久久久免| 国产女主播在线喷水免费视频网站 | 精品国内亚洲2022精品成人| 国产亚洲91精品色在线| 蜜桃亚洲精品一区二区三区| 99视频精品全部免费 在线| 亚洲一级一片aⅴ在线观看| 亚洲欧美中文字幕日韩二区| 久久亚洲国产成人精品v| 婷婷色综合大香蕉| 色播亚洲综合网| 又爽又黄a免费视频| 波野结衣二区三区在线| av又黄又爽大尺度在线免费看| 午夜免费激情av| 日韩视频在线欧美| 免费电影在线观看免费观看| 亚洲va在线va天堂va国产| 午夜免费男女啪啪视频观看| 久久这里只有精品中国| 久久久久久久大尺度免费视频| 国产av在哪里看| 久久精品夜色国产| 久久久午夜欧美精品| 久99久视频精品免费| 夜夜看夜夜爽夜夜摸| 丝袜美腿在线中文| 成年版毛片免费区| 性插视频无遮挡在线免费观看| 免费大片黄手机在线观看| 综合色av麻豆| 丝瓜视频免费看黄片| 你懂的网址亚洲精品在线观看| 亚州av有码| 51国产日韩欧美| 免费看不卡的av| 美女主播在线视频| 美女内射精品一级片tv| 女人久久www免费人成看片| 国产黄片视频在线免费观看| www.av在线官网国产| 久久精品久久精品一区二区三区| 九草在线视频观看| 在线观看免费高清a一片| 久久久久国产网址| 国产黄色小视频在线观看| 伦精品一区二区三区| 18禁在线播放成人免费| 国产精品99久久久久久久久| 在线观看美女被高潮喷水网站| 中文资源天堂在线| 日本免费a在线| 欧美人与善性xxx| 免费大片18禁| 亚洲在久久综合| 在线观看美女被高潮喷水网站| 亚洲无线观看免费| 在线观看美女被高潮喷水网站| 91狼人影院| 嫩草影院精品99| 18+在线观看网站| or卡值多少钱| 99re6热这里在线精品视频| 听说在线观看完整版免费高清| 97超碰精品成人国产| or卡值多少钱| 特级一级黄色大片| 91久久精品国产一区二区成人| 精品酒店卫生间| 日日摸夜夜添夜夜爱| 亚洲欧美日韩东京热| 久久99热这里只频精品6学生| 久久精品国产亚洲av涩爱| 综合色丁香网| 伦理电影大哥的女人| 午夜福利视频精品| 插逼视频在线观看| 久久久久网色| 亚洲精品日韩在线中文字幕| 99热这里只有是精品在线观看| 亚洲精品,欧美精品| 久久精品久久久久久久性| 亚洲乱码一区二区免费版| 又爽又黄无遮挡网站| 街头女战士在线观看网站| 干丝袜人妻中文字幕| 亚洲熟女精品中文字幕| 亚洲久久久久久中文字幕| 在线观看一区二区三区| 亚洲天堂国产精品一区在线| 国产亚洲91精品色在线| 免费看不卡的av| 成人漫画全彩无遮挡| 国产精品99久久久久久久久| 久久韩国三级中文字幕| 亚洲国产高清在线一区二区三| 亚洲四区av| 麻豆久久精品国产亚洲av| 久久久久网色| 日日啪夜夜撸| 晚上一个人看的免费电影| 国产一区二区在线观看日韩| 又爽又黄a免费视频| 丰满人妻一区二区三区视频av| 亚洲av成人精品一区久久| 国产av不卡久久| 小蜜桃在线观看免费完整版高清| 在线观看美女被高潮喷水网站| 亚洲欧美日韩东京热| 少妇猛男粗大的猛烈进出视频 | 国产真实伦视频高清在线观看| 99久国产av精品| 最新中文字幕久久久久| av黄色大香蕉| 床上黄色一级片| 国产成人午夜福利电影在线观看| 一夜夜www| 三级经典国产精品| 日本欧美国产在线视频| 欧美精品一区二区大全| 建设人人有责人人尽责人人享有的 | 狠狠精品人妻久久久久久综合| 亚洲欧美成人综合另类久久久| 精品久久久久久成人av| 日本与韩国留学比较| 国产片特级美女逼逼视频| 国产精品.久久久| 狂野欧美激情性xxxx在线观看| 午夜精品一区二区三区免费看| 日韩欧美精品v在线| 大香蕉97超碰在线| 成人亚洲精品一区在线观看 | 国产免费又黄又爽又色| 草草在线视频免费看| 成年免费大片在线观看| 天天躁夜夜躁狠狠久久av| 日本一二三区视频观看| 亚洲经典国产精华液单| 亚洲精品久久午夜乱码| 久久久欧美国产精品| 亚洲av免费在线观看| 日本三级黄在线观看| 夜夜看夜夜爽夜夜摸| 69av精品久久久久久| 国产午夜精品一二区理论片| av又黄又爽大尺度在线免费看| 色尼玛亚洲综合影院| 日本午夜av视频| 韩国高清视频一区二区三区| ponron亚洲| 日本欧美国产在线视频| 大陆偷拍与自拍| 亚洲国产精品成人综合色| 久久久久久久久久成人| 激情 狠狠 欧美| 欧美潮喷喷水| 精品午夜福利在线看| 中文字幕制服av| 亚洲精品久久久久久婷婷小说| 在线 av 中文字幕| 欧美日本视频| 亚洲熟妇中文字幕五十中出| 极品少妇高潮喷水抽搐| 免费播放大片免费观看视频在线观看| 人妻系列 视频| 国产精品综合久久久久久久免费| 最近手机中文字幕大全| 看十八女毛片水多多多| 午夜亚洲福利在线播放| kizo精华| 亚洲内射少妇av| 国产免费又黄又爽又色| 国产精品国产三级国产av玫瑰| 国产在线一区二区三区精| 最新中文字幕久久久久| 久热久热在线精品观看| 自拍偷自拍亚洲精品老妇| 最近2019中文字幕mv第一页| 日韩欧美 国产精品| 在现免费观看毛片| 熟女电影av网| 欧美日韩国产mv在线观看视频 | 亚洲国产精品成人久久小说| 亚洲国产高清在线一区二区三| 国产精品久久视频播放| 久久久久免费精品人妻一区二区| a级毛片免费高清观看在线播放| 天堂中文最新版在线下载 | 高清av免费在线| 欧美97在线视频| 午夜激情久久久久久久| 亚洲在线观看片| 国产精品一区二区三区四区久久| 日本一本二区三区精品| 免费不卡的大黄色大毛片视频在线观看 | 亚洲成色77777| 欧美xxxx黑人xx丫x性爽| 国产精品1区2区在线观看.| 色播亚洲综合网| 亚洲欧美日韩东京热| 搡老妇女老女人老熟妇| 日韩成人伦理影院| 搡老妇女老女人老熟妇| 午夜福利在线观看免费完整高清在| 三级国产精品片| 亚洲伊人久久精品综合| 久久久精品免费免费高清| 啦啦啦中文免费视频观看日本| 成年女人看的毛片在线观看| 啦啦啦啦在线视频资源| 97超视频在线观看视频| 亚洲性久久影院| 插阴视频在线观看视频| 日产精品乱码卡一卡2卡三| 国产在线一区二区三区精| 久久久久久久午夜电影| 亚洲av二区三区四区| 精品一区二区三区视频在线| 欧美日韩精品成人综合77777| 国产免费又黄又爽又色| 日日干狠狠操夜夜爽| 国内精品美女久久久久久| 超碰97精品在线观看| 国产精品国产三级国产av玫瑰| 中文资源天堂在线| 久久久久九九精品影院| 国产精品福利在线免费观看| 真实男女啪啪啪动态图| 综合色丁香网| 国产精品一区二区性色av| 91精品国产九色| 亚洲熟妇中文字幕五十中出| 久久鲁丝午夜福利片| 在线 av 中文字幕| 日韩伦理黄色片| av专区在线播放| 男女视频在线观看网站免费| 久久精品人妻少妇| 九九爱精品视频在线观看| 久久久久久国产a免费观看| 国产精品.久久久| 最近2019中文字幕mv第一页| 精品久久久久久电影网| 欧美日本视频| 国产亚洲av嫩草精品影院| 精品人妻视频免费看| 黄色欧美视频在线观看| 欧美zozozo另类| 纵有疾风起免费观看全集完整版 | 亚洲av国产av综合av卡| 极品少妇高潮喷水抽搐| 免费看美女性在线毛片视频| 国产成人精品久久久久久| 极品教师在线视频| 一级片'在线观看视频| www.av在线官网国产| 国产精品美女特级片免费视频播放器| 婷婷六月久久综合丁香| 免费av观看视频| 亚洲精品国产av成人精品| 亚洲成人精品中文字幕电影| 日韩视频在线欧美| 色播亚洲综合网| 午夜日本视频在线| 欧美高清性xxxxhd video| 国产亚洲午夜精品一区二区久久 | 亚洲国产精品专区欧美| 国产亚洲精品av在线| 大香蕉97超碰在线| 看非洲黑人一级黄片| 赤兔流量卡办理| 一级毛片我不卡| 亚洲真实伦在线观看| 狠狠精品人妻久久久久久综合| 色吧在线观看| 成年女人在线观看亚洲视频 | 综合色av麻豆| 亚洲无线观看免费| av在线播放精品| 成年版毛片免费区| 禁无遮挡网站| 日韩av不卡免费在线播放| 美女高潮的动态| 国产精品av视频在线免费观看| 亚洲天堂国产精品一区在线| xxx大片免费视频| 久久久久久久久中文| 一夜夜www| 成人亚洲欧美一区二区av| 亚洲国产色片| 2022亚洲国产成人精品| 国产单亲对白刺激| 日韩中字成人| 国产 一区 欧美 日韩| 亚洲欧洲日产国产| 亚洲欧美日韩东京热| 一本久久精品| 久久久久久九九精品二区国产| 99热这里只有是精品在线观看| 国产不卡一卡二| 真实男女啪啪啪动态图| 色哟哟·www| 久久精品国产亚洲av涩爱| 欧美成人一区二区免费高清观看| 国产一级毛片七仙女欲春2| 三级毛片av免费| 日韩中字成人| 亚洲人成网站高清观看| 国产精品爽爽va在线观看网站| 欧美不卡视频在线免费观看| 六月丁香七月| 免费观看在线日韩|