本帖最后由 xttyyy 于 2017-9-27 17:44 编辑
VTOL早在2016年就已经被Ardupilot全系列飞控所支持，并且在国外被多次验证。今年国内也逐渐出现了很多垂直起降飞行器，网上几千块就能买一整套空机模型，但是相应的中文材料比较缺乏，因此我将ardupilot.com官方网站的垂直起降指南进行了翻译，希望对大家有所帮助。目前只完成了重要基础内容的翻译，还有20%左右没有完成，后续会补充。 本文说明如何设置和使用“QuadPlane”固件操作复合翼飞行器， QuadPlane 简介·
· QuadPlane是固定翼和多旋翼的组合体，这种飞行器可以垂直起降，具有更好的飞行速度和范围，并且可以根据不同任务在空中悬停。 · QuadPlane是在固定翼飞行器的基础上，添加4到8个旋翼马达。飞行员可以通过新增的飞行模式和命令让QuadPlane像多旋翼一样起飞、降落和飞行，并且自动或半自动的在固定翼和多旋翼间平滑切换。额外的马达也可以在传统固定翼模式下提供升力，并辅助保持姿态稳定。 导入固件· 从固定翼3.5之后加入了对QuadPlane的支撑。 · 安装QuadPlane固件后，可以在参数列表中找到Q_ENABLE参数，默认为0，关闭复合翼模式，设置到1后会启用复合翼功能。所有的复合翼特殊参数都以"Q_"开头。 安装复合翼 在组装复合翼前，要仔细进行设计。本段落会为你的额安装工作提供一些通用的建议和指导。 基本原则 很多固定翼飞行器都可以经过改造具备垂直起降的能力。尽管官方使用QuadPlane（四旋翼固定翼）命名这些复合翼飞机，但是几乎所有类型的多旋翼都可以被用于复合翼，如四轴、八轴、三轴等等。 成功改造的要素如下： · 固定翼模式可以承担飞机以及所有旋翼机构的重量。 · 要准备足够的动力，旋翼模式不仅要可以负担所有重量，还要考虑固定翼翼面带来的升力损失。 · 旋翼平面的上下要有足够的空间，以保证空气动力学上的拉力效率。 · 最小化翼面的扭曲和弹性变形，以保证旋翼的动力全部作为升力 · 尽量减小旋翼动力系统和桨平面带来的飞行阻力。 在设计QuadPlane可以考虑使用eCalc软件来帮助计算系统动力是否满足需求，帮助选择合适的 电机、电调、螺旋桨和 电池。无刷电机的推重比更高，可以有效减轻飞行器重量。 Perhapssurprisingly, it is sometimes possible to increase the potential range of anaircraft using a QuadPlane conversion. This may seem counter intuitive as aQuadPlane conversion will both add weight and increase aerodynamic drag to anairframe. Thereason why range can be increased is the extra carrying capacity of aQuadPlane. Many fixed wing aircraft are limited in the amount of battery theycan carry due to the requirements for reliable launch. During launch, andespecially when using a flying launch such as a catapult or bungee, theaircraft needs to rapidly accelerate to an airspeed above its stall speed. Ifit fails to reach that speed suffiently quickly then it will crash. A QuadPlaneavoids this problem by taking off vertically, and can spend longer on theacceleration needed to sufficient speed for forward flight. Thismeans it is often possible to pack a lot more battery into a QuadPlane than ispossible in the same airframe without VTOL motors. The extra battery capacitycan more than make up for the increased weight and drag of the VTOL motors. To makethe most of this advantage you need to do very rapid VTOL takeoffs and landingsto minimise the battery consumption in VTOL flight. The video belowdemonstrates just how rapid a takeoff can be achieved with a properly setupquadplane. 一些组装日志Here are some build logs of a fewQuadPlanes that may help you with ideas for your own build. if you would like to add your own buildto this list then please contact the ArduPilot dev team. 电机设置QuadPlane 固件支持大多数多旋翼方式，如四旋翼、八旋翼、6旋翼等。 旋翼马达的顺序和多旋翼一致，只是其实通道从1调整到了5，如四旋翼为5678. 如下为传统四旋翼作为复合翼模式的通道对应关系。 · Channel 5: Front right motor, counter-clockwise · Channel 6: Rear left motor, counter-clockwise · Channel 7: Front left motor, clockwise · Channel 8: Rear right motor, clockwise 如下为一个四轴双桨复合翼的通道对应关系。 · Channel 5: Front right top motor, counter-clockwise · Channel 6: Front left top motor, clockwise · Channel 7: Rear left top motor, counter-clockwise · Channel 8: Rear right top motor, clockwise · Channel 9: Front left bottom motor, counter-clockwise · Channel 10: Front right bottom motor, clockwise · Channel 11: Rear right bottom motor, counter-clockwise · Channel 12: Rear left bottom motor, clockwise 固定翼模式的输出通道还是1到4未变。 同时修改 Q_FRAME_CLASS andQ_FRAME_TYPE.可以改变旋翼的动力分布模式，其中 Q_FRAME_CLASS 对应: · 1 for quad · 2 for hexa · 3 for octa · 4 for octaquad · 5 for Y6 · 7 for Tri · 10 for Tailsitter Q_FRAME_TYPE 对应 · 0 for plus frame · 1 for X frame · 2 for V frame · 3 for H frame · 11 for FireFly6Y6 (for Y6 only) 使用自定义电机映射通过修改各通道的SERVOn_FUNCTION.可以自定义电机映射关系，多旋翼电机对应的功能编码为： · 33: motor1 · 34: motor2 · 35: motor3 · 36: motor4 · 37: motor5 · 38: motor6 · 39: motor7 · 40: motor8 所以，如果想修改旋翼对应的通道为9到12，可以做如下修改 · SERVO9_FUNCTION = 33 · SERVO10_FUNCTION = 34 · SERVO11_FUNCTION = 35 · SERVO12_FUNCTION = 36 电调校准基本所有的电调都需要预先进行PWM的校准工作，以保证大家在相同输入下具备相同的转速。一般电调厂家的校准程序都需要分别输入最高和最低的PWM脉冲值。在QuadPlane中，提供了同时对几个电机的校准方式。 电调校准 (3.6.0 以后)通过设置 Q_ESC_CAL参数允许在QSTABILIZE模式下进行电调校准。该参数有两个值： 1. Q_ESC_CAL=1 飞行器解锁后，各电机的输出直接连接到 遥控器摇杆的输入。 2. Q_ESC_CAL=2 飞行器解锁后，各电机输出最大值。 Q_ESC_CAL=1时的校准方式为： 1. 拆除所有螺旋桨 2. 为飞控上电（不要给马达上电），如果飞行器无法单独给飞控或马达通电的话，可以通过usb线先行为飞控供电。 3. 设置Q_ESC_CAL 为 1 4. 切换到QSTABILIZE 模式 5. 打开安全开关 6. 解锁飞行器，马达输出的PWM值直接来自遥控器。 7. 将油门摇杆调整到最高。 8. 为电调和电机供电。 9. 听到电调鸣叫两声（各厂家有微小差异），表明电调接收到最高PWM 10. 遥控器油门摇杆推到最低。 11. 应该可以听到电调的提示音，表示校准完成。 Q_ESC_CAL=2时的校准方式为 1. 拆除所有螺旋桨 2. 为飞控上电（不要给马达上电），如果飞行器无法单独给飞控或马达通电的话，可以通过usb线先行为飞控供电。 3. 设置 Q_ESC_CAL为2 4. 切换到QSTABILIZE 模式。 5. 打开安全开关。 6. 解锁飞行器，马达输出的PWM为最大值。 7. 为电调和电机供电。 8. 听到电调鸣叫两声（各厂家有微小差异），表明电调接收到最高PWM 9. 锁定飞行器。 10. 听到电调鸣叫两声（各厂家有微小差异），表明电调接收到最高PWM 老固件电调校准 (3.5.3 以前)1. remove your propellers for safety 2. power up just the flight board and notyour motors. If you don’t have the ability to isolate power to the ESCs when onbattery power then power up your flight board on USB power 3. set both theparameters Q_M_SPIN_ARMED and Q_THR_MID to 1000. This setsthe PWM output when armed at zero throttle to full power 4. set the safety switch off to activatethe outputs 5. arm your aircraft. The PWM output on allquad motors will now climb to maximum. 6. add power to your ESCs by connecting thebattery 7. wait for the ESCs to beep to indicatethey have registered the maximum PWM 8. disarm your aircraft. The ESCs shouldbeep again indicating they have registered minimum PWM Now set the Q_M_SPIN_ARMED and Q_THR_MIDparameters back to the correct values. A value of 50 for Q_M_SPIN_ARMED is areasonable starting point. For Q_THR_MID a value of between 500 and 600 is gooddepending on the power of your motors 参数设置所有复合翼的参数和传统多旋翼非常相似，仅仅以"Q_"开头， 一些关键参数如下： · 通过设置Q_ENABLE为1可以启用复合翼模式，设置后需要重新刷新参数列表。 · Q_THR_MIN_PWM 和Q_THR_MAX_PWM 可以设置旋翼马达们的最大和最小输出值， (允许旋翼马达和固定翼马达具备不同的PWM输出范围). · Q_A_RAT_RLL_P 和 Q_A_RAT_PIT_P是一组比较重要的调整参数。他们默认是0.25，不过对于复合翼，可能需要被设置为更高的值。 · Q_M_SPIN_ARMED 可以设置解锁时马达的初始转速。 · 建议设置ARMING_RUDDER 为2以启用方向舵. 否则就要小心，不要同时打满左方向的同时给出0油门，防止飞行器在天上被锁定。 · Q_THR_MID用于设置固定翼和旋翼的转换平滑程度，默认为500，表示用50%的旋翼油门实现悬停。如果你的飞行器需要更高或更低的输出才能保证悬停，请修改这个参数，防止在切换过程中出现剧烈抖动。 注意 QuadPlane 需要GPS信号以进行一些特定操作。不要尝试在室内使用QuadPlane飞行。 飞行模式uadPlane 具有下述5各飞行模式 注意 如果MissionPlanner版本过于陈旧，可能需要直接修改值类型来设置上述模式。 如果你对于飞行多旋翼很熟悉，那么可以很轻松的过渡到复合翼飞行上。仅有的区别在于固定翼和旋翼的模式切换过程 注意 QLOITER模式的降落检测程序与多旋翼模式不同，只要检测到GPS速度，就会尝试启动马达进行提升，以维持飞机位置，所以当飞机降落后，最好尽快切换到QHOVER或者QSTABILIZE模式，防止降落后又自行起飞，防止发生危险。 需要回避的飞行模式复合翼飞行要求飞控总是要知道操纵者的速度和姿态预期，因此不要讲复合翼切换到下述模式。ACRO · STABILIZE · TRAINING 这些模式下，控制者通过遥控器的输入不足以指明飞行器的目标姿态和爬升速度，飞控逻辑不会控制旋翼马达。当需要手动操作飞行器时，可以使用FBWA模式代替STABILIZE。 未来将会添加对这些模式的支持。 另外一个不能使用的是MANUAL模式，这个模式常备固定翼飞手用于微调和滑翔。 复合翼实飞请仔细阅读如下内容，以保证飞行器的安全。 过程转换 QuadPlane过程转换是指在旋翼为主和固定翼为主的模式中进行切换。转换是双向的，即可以由飞手发出命令控制，也可以根据飞行速度和飞行模式自动执行。· 切换到MANUAL模式时，旋翼马达会立即停止。 · 当从固定翼模式切换到QuadPlane特有模式后，固定翼马达会马上停止，固定翼的几个 舵机会仍然工作，以帮助保持平衡。
仅有一种情况下，转换到QuadPlane模式后，固定翼马达不会立即停止工作，那就是设置了 Q_VFWD_GAIN 参数为非零值，此时固定翼马达会仍然启动，用于抗风。 The QuadPlane code can also beconfigured to provide assistance to the fixed wing code in any flight modeexcept MANUAL. To enable quad assistance you shouldset Q_ASSIST_SPEED parameter to the airspeed belowwhich you want assistance. 旋翼马达可以在固定翼模式（MANUAL除外）的飞行中，提供额外的辅助功能。通过设置 Q_ASSIST_SPEED参数，指定启用固定翼辅助功能的空速值。 当 Q_ASSIST_SPEED非零时，一旦飞行器速度小于这个阈值，旋翼马达会帮助维持升力和姿态稳定。有效保障飞行器在固定翼FBWA模式下低速飞行，或者固定翼模式下的自动降落。 旋翼马达根据不同的飞行模式也提供不同程度的辅助能力。在自动或半自动飞行时，辅助模式会始终开启。而在手动模式时，会被禁用。 一些需要注意的事项如下： · 自动模式下，旋翼马达根据下一个航点的位置和方向，尝试提供升力和旋转力矩。 · 在固定翼的LOITER，RTL或GUIDED模式下，不论飞行器的上升或旋转速度是多少，旋翼马达都会辅助飞行。 · 在固定翼的CRUISE或者FBWB模式下，旋翼马达会根据升降舵和方向舵的输入，尝试提供升力和旋转。 · 在FBWA模式下，旋翼马达根据升降舵的输入进行响应。当拉杆时，旋翼马达尝试爬升，推杆时，旋翼马达会调整以维持一个固定的下降速度。 · 在自动调参模式，旋翼马达的动作与FBWA想同。建议自动调参时，不要把 Q_ASSIST_SPEED设置过高，因为旋翼马达会影响固定翼的调参。 复合翼的失控返航有几种模式： · 像固定翼一样在返航点盘旋 · 以旋翼模式飞回起飞位置并降落。 · 以固定翼模式飞到接近家的位置，切换到旋翼模式并降落。 固定翼 RTL仅当需要旋翼辅助维持高度和姿态时，才会启动。ALT_HOLD_RTL设置悬停高度。 VTOL RTL (QRTL)
Hybrid RTL这种模式，飞行器按照固定翼方式飞行到接近位置，切换到旋翼进行着陆。设定 Q_RTL_MODE到1可以启动这种返航模式。ALT_HOLD_RTL指定了固定翼返航高度。对于大多数复合翼，ALT_HOLD_RTL设置为15米比较合适。RTL_RADIUS设置固定翼模式靠近目标点的范围，如果RTL_RADIUS没有设置，按照WP_LOITER_RAD进行靠近判断。切换到旋翼模式后在 Q_RTL_ALT高度飞行，之后飞行器缓慢降落。 Understanding hybridaircraft can be difficult at first, so below are some scenarios and how theArduPilot code will handle them. QHOVER悬停切换到FBWA模式飞行器会继续悬停，等待飞手操作。如果遥控器输入0油门，飞行器会继续悬停在当前高度，保持水平，会随着风漂移。 如果推油门后，固定翼马达分启动，飞行器加速前进。旋翼马达在低速时会继续提供升力和稳定。可以通过副翼和升降杆控制飞行器高度。升降舵会影响旋翼发动机转速，以影响爬升速度。 副翼和升降输入也控制飞行器姿态，如右向副翼会让飞行器向右移动，同时也会向右转向（QuadPlane做了方向舵副翼联动） FBWA快速飞行中切换到QHOVER模式旋翼马达立即启动并且开始维持当前高度，升降速率取决于油门位置。固定翼马达将会停止，因为惯性飞行器会继续向前移动。空气阻力会慢慢导致飞行器停止移动。此时可以通过副翼和升降控制飞行器姿态，通过转向摇杆控制飞行器朝向。 悬停中切换到RTL模式飞行器会转换到固定翼模式，旋翼马达继续提供升力，帮助稳定姿态，固定翼马达启动，飞行器开始前进。标准的固定翼RTL模式开始，飞行器会在目标点上空盘旋。如果设置了 RTL_AUTOLAND，飞行器会执行固定翼模式的滑降；如果设置了 Q_RTL_MODE为1，飞行器会切换到旋翼模式，垂直降落。 · 通过QLOITER 或者 QHOVER起飞 · 切换到 FBWA 模式，加大油门，开始固定翼飞行。 · 切换到QHOVER 模式返回旋翼状态。 风速适应Weathervaning and Wind HoldFlying a QuadPlane in significant levelsof wind can present a challenge. The issue is that the large wing surfaceoffers a lot of surface area for the wind to interact with. That can lead to areduction in attitude and position control and high motor and ESC load. To reduce the impact of wind when flyingin VTOL modes the ArduPilot QuadPlane code supports two features: · Active weathervaning · Position hold using forward motor Together these two features can greatlyreduce the impact of wind on VTOL flight by keeping the aircraft pointed intothe wind and reducing the area of the wing exposed to the wind. Active WeathervaningActive weathervaningacts to turn the nose of the aircraft into the wind when flying inposition-controlled VTOL modes. You can enable active weathervaning by settingthe Q_WVANE_GAINparameterto a non-zero value. The default is not to use active weathervaning. The way it works is theautopilot looks at the roll attitude needed to control the desired position.The basic algorithm is “turn into the roll”. If the aircraft needs to roll tothe right in order to hold position then it will turn in that direction on theassumption that the right roll is needed in order to hold against the wind. How quickly the aircraftturns is given by the Q_WVANE_GAIN parameter. A good value to start with is0.1. Higher values will make the aircraft turn into the roll more quickly. Ifthe value is too high then you can get instability and oscillation in yaw. To cope with a smallamount of trim in the aircraft there is an additional parameter Q_WVANE_MINROLL whichcontrols the minimum roll level before weathervaning will be used. Thisdefaults to one degree. If you find your aircraft starts yawing even in no windthen you may need to raise this value. Active weathervaning isonly active in VTOL modes, and VTOL sections of AUTO modes (such as VTOLtakeoff and VTOL landing). It is not active in QSTABILIZE and QHOVER modes asthose are not position controlled modes. It is active is QLOITER, QLAND andQRTL modes. Using the Forward MotorIn addition to activeweathervaning, the QuadPlane code supports using the forward motor to hold thepitch level in VTOL flight modes. To enable use of the forward motor forposition hold you need to set the Q_VFWD_GAIN parameterto a non-zero value. The way it works is tolook at two factors: · the navigation attitude pitchof the aircraft · the difference between thedesired forward velocity and the actual forward velocity These are combined withthe Q_VFWD_GAIN to ramp up and down the throttle on the forward motor in orderto minimize the attitude pitch of the aircraft. That keeps the area of wingexposed to the wind minimized which can reduce VTOL motor load. A good value to startwith for Q_VFWD_GAIN is 0.05. Higher values will use the forward motor moreaggressively. If the value is too high you can get severe pitch oscillations. Note that you can alsouse reverse thrust on the forward motor. If your THR_MIN parameteris less than zero then reverse thrust is available and the motor will usereverse thrust to slow down or move backwards as needed. See the reverse thrust sectionin the automatic landing documentationfor more details. As with activeweathervaning, using the forward motor is only enabled in position controlledVTOL modes. This means it is not enabled in QSTABILIZE or QHOVER flight modes.It is available in QLOITER, QRTL, QLAND and in AUTO mode when executing VTOLflight commands. QuadPlane 任务模式You can ask the QuadPlane code to fly AUTO missions, with everything from automatic vertical takeoff, tomixtures of fixed wing and VTOL waypoints and automated VTOL landings. Theresult is an extremely versatile aircraft capable of long range missions withvertical takeoff and landing. The most common use of VTOL missioncommands in a QuadPlane is an automatic VTOL takeoff. To use a VTOL takeoff youplan your auto mission as usual with your ground stations mission editor, butinstead of a NAV_TAKEOFF command for a fixed wing takeoff you instead use aNAV_VTOL_TAKEOFF command for a VTOL takeoff. The only parameter to a NAV_VTOL_TAKEOFF isthe altitude above the takeoff point where the takeoff is complete. Once thataltitude is reached the aircraft will move to the next waypoint, transitioningto fixed wing flight as needed. The latitude and longitude of theNAV_VTOL_TAKEOFF command is ignored. AUTOVTOL LandingThere are several ways to perform anautomatic VTOL landing. The simplest is to include a NAV_VTOL_LAND command inyour mission. That command should use an altitude of zero, and have a latitudeand longitude of the landing position. When using NAV_VTOL_LAND it is important tohave the right horizontal spacing between that waypoint and the previous one.As soon as the aircraft starts on the NAV_VTOL_LAND waypoint it will transitionto VTOL flight, which means it will start flying much more slowly than it doesin fixed wing flight. So you need to put the previous waypoint the rightdistance from the landing point. If it is too far from the landing point thenthe aircraft will spend a lot of time in VTOL flight which will waste battery.If it is too close to the landing point then it will have to stop very abruptlyin order to land. For most small QuadPlanes a distance ofbetween 60 and 80 meters from the last waypoint to the landing point is good.For larger faster flying QuadPlanes you will need a larger distance. Also make sure the altitude of the lastwaypoint is chosen to be within a reasonable height of the landing. The VTOLlanding approach will be done at whatever height the aircraft is at when itstarts on the NAV_VTOL_LAND waypoint. So you would typically want the previouswaypoint to have an altitude of about 20 meters above the ground. Returnto LaunchAn alternaive to using a NAV_VTOL_LANDcommand is to use a RETURN_TO_LAUNCH command, and to set the Q_RTL_MODE parameter to 1. The advantage of using a RETURN_TO_LAUNCHwith Q_RTL_MODE set is that the aircraft will automatically use fixed wingflight until it gets within RTL_RADIUS of the return point. That makes it easier to plan missions witha VTOL landing from anywhere in the flying area. To mix fixed wing and VTOL flight in onemission you can use the DO_VTOL_TRANSITION command in your mission. ADO_VTOL_TRANSITION command takes a single parameter. If the parameter is set to3 then the aircraft will change to VTOL mode. If the parameter is set to 4 thenit will change to fixed wing mode. In the above example the aircraft will do aVTOL takeoff, then it will fly to waypoint 1 as a fixed wing aircraft. It willthen switch to VTOL mode and fly as a VTOL aircraft through waypoints 4 and 5,then it will switch back to fixed wing flight to reach waypoint 7, beforefinally flying home and landing as a VTOL aircraft (assuming Q_RTL_MODE is setto 1). Hoveringin a MissionBy setting the Q_GUIDED_MODE parameter to 1 your quadplane will handle loiter commands in GUIDED mode and in AUTO missions as a VTOL aircraft. For example, thefollowing mission: the aircraft will pause while hovering for10 seconds at waypoint 3. It will fly the rest of the mission as a fixed wingaircraft. This can be very useful for getting good photographs of a number oflocations in a mission while flying most of the mission as an efficient fixedwing aircraft. 引导模式In addition to AUTOmode, you can also use a QuadPlane in GUIDED mode.To use VTOL support in GUIDED mode you need to set the Q_GUIDED_MODE parameterto 1. When set, GUIDED mode behaviour will change so that the position hold atthe destination will be done as a VTOL hover rather than a fixed wing circle. The approach to theguided waypoint will be done as a fixed wing aircraft. The transition to VTOLflight will begin at the WP_LOITER_RAD radiusin meters. This should be set appropriately for your aircraft. A value of 80meters is good for a wide range of QuadPlanes. When hovering at thedestination in GUIDED mode if a new GUIDED destination is given then theaircraft will transition back to fixed wing flight, fly to the new location andthen hover again in VTOL mode.
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发表于 2017-9-27 14:55
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