基于大疆 MSDK 实现的无人机视觉引导自适应降落功能

介绍基于大疆 MSDK 实现无人机视觉引导自适应降落功能。针对 FlyTo 功能不可用及 GPS 精度不足问题，采用虚拟摇杆导航替代，结合视觉识别计算 X/Y 偏移量。核心策略是根据高度动态调整下降速度和位置对齐阈值，高空允许较大误差，低空严格限制。通过关闭下视避障防止误停，最终实现安全精确的自动降落。

PhpPioneer发布于 2026/4/5更新于 2026/4/131 浏览

基于大疆 MSDK 实现的无人机视觉引导自适应降落功能

概述

最初需求：想要无人机在执行完航线任务后，一键落到一个指定的位置，简化人工控制。

实现一套完整的无人机自主降落功能，通过虚拟摇杆控制使无人机飞向指定位置，再利用视觉识别引导无人机精确降落到具体位置。本文中采用自适应降落策略，根据高度动态调整精度要求和下降速度，以实现安全、精确的降落。

核心点:

虚拟摇杆导航替代 FlyTo 功能
双轴 (X/Y) 位置偏移实时调整
高度自适应降落策略
视觉识别引导定位
智能避障管理

系统架构

整体流程

用户触发 Return to Vehicle
获取无人机 GPS 位置，计算与目标点距离
启动虚拟摇杆导航，以 5m/s 飞向目标位置
距离小于 10m 时，开始自适应降落
视觉识别系统计算 X/Y 偏移量并更新到 ViewModel
根据高度分段判断（高空/中空/低空/极低空）调整速度和下降速度
若偏移大于阈值 2 倍，停止下降只调整；否则边调整边下降
高度小于 5m 时关闭下视避障
高度小于等于 0.1m 时着陆完成清理资源

技术实现思路

第一步：让无人机飞到目标位置

问题分析

遥控器控制的无人机在执行完航线任务之后，飞到给定降落点（汽车或其他载具上）。最初的想法是使用 DJI SDK 提供的 FlyTo 功能，直接指定目标 GPS 坐标让无人机飞过去。但在实际测试中，发现部分机型（如 M3E）并不支持 FlyTo 功能。

机型是否支持 FlyTo 功能参考文档： https://developer.dji.com/doc/mobile-sdk-tutorial/cn/tutorials/intelligent-flight.html

解决方案：虚拟摇杆导航

既然 FlyTo 功能不可用，那就用虚拟摇杆功能进行模拟。

思路:

计算当前位置到目标位置的方位角(bearing)
将方位角转换为速度分量(南北/东西)
持续发送虚拟摇杆指令，让无人机朝目标飞行
实时监测距离，接近目标时停止

方位角计算:

private fun calculateBearing(latA: Double, lonA: Double, latB: Double, lonB: Double): Double {
    val lat1 = Math.toRadians(latA)
    val lat2 = Math.toRadians(latB)
     dLon = Math.toRadians(lonB - lonA)
     y = Math.sin(dLon) * Math.cos(lat2)
     x = Math.cos(lat1) * Math.sin(lat2) - Math.sin(lat1) * Math.cos(lat2) * Math.cos(dLon)
     bearing = Math.toDegrees(Math.atan2(y, x))
    bearing = (bearing + ) %  
     bearing 
}

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private fun startDynamicAdjustment() { isAdjusting = true virtualStickHandler = Handler(Looper.getMainLooper()) val adjustTask = object : Runnable { override fun run() { if (!isAdjusting) return // 1. 获取当前状态 val currentAltitude = FlightControllerKey.KeyAltitude.create().get(0.0) val currentXOffsetAbs = Math.abs(xOffset) val currentYOffsetAbs = Math.abs(yOffset) // 2. 检查是否着陆 if (currentAltitude <= 0.1) { stopLanding() return } // 3. 低空时关闭下视避障 if (currentAltitude <= 5.0 && !downwardObstacleDisabled) { downwardObstacleDisabled = true setObstacleAvoidanceEnable(false, PerceptionDirection.DOWNWARD) } // 4. 计算自适应参数 val offsetThreshold = getOffsetThreshold(currentAltitude) val descentSpeed = getDescentSpeed(currentAltitude, currentXOffsetAbs, currentYOffsetAbs) // 5. 构建虚拟摇杆指令 val adjustParam = VirtualStickFlightControlParam().apply { rollPitchCoordinateSystem = FlightCoordinateSystem.BODY verticalControlMode = VerticalControlMode.VELOCITY rollPitchControlMode = RollPitchControlMode.VELOCITY // 水平调整 roll = if (currentXOffsetAbs > offsetThreshold) { if (xOffset > 0) ADJUSTMENT_SPEED else -ADJUSTMENT_SPEED } else 0.0 pitch = if (currentYOffsetAbs > offsetThreshold) { if (yOffset > 0) ADJUSTMENT_SPEED else -ADJUSTMENT_SPEED } else 0.0 // 垂直下降 verticalThrottle = -descentSpeed } // 6. 发送指令 VirtualStickManager.getInstance().sendVirtualStickAdvancedParam(adjustParam) // 7. 100ms 后再次执行 (10Hz) virtualStickHandler?.postDelayed(this, 100) } } virtualStickHandler?.post(adjustTask) }

/** * One-key return to vehicle function (using Virtual Stick instead of FlyTo) * 1. Get aircraft current location * 2. Calculate distance to vehicle using Haversine formula * 3. If distance > 500m, reject with error * 4. Use Virtual Stick to navigate to vehicle location * 5. Switch to precision adjustment when close enough */ fun returnToVehicle(callback: CommonCallbacks.CompletionCallback) { // Get aircraft current location val aircraftLocation = getAircraftLocation() if (aircraftLocation == null || !isLocationValid(aircraftLocation.latitude, aircraftLocation.longitude)) { callback.onFailure(DJICommonError.FACTORY.build("无法获取无人机位置信息")) return } // Vehicle coordinates (hardcoded for now, will be replaced with API later) // TODO: Replace with actual vehicle GPS coordinates from API val vehicleLatitude = 22.579 // Example coordinates val vehicleLongitude = 113.941 // Example coordinates // Calculate distance using Haversine formula val distance = calculateDistance( aircraftLocation.latitude, aircraftLocation.longitude, vehicleLatitude, vehicleLongitude ) // Distance validation: reject if > 500m if (distance > 500) { callback.onFailure(DJICommonError.FACTORY.build("距离过远：${String.format("%.2f", distance)}m, 超出 500m 限制")) return } // Start virtual stick navigation to vehicle location toastResult?.postValue(DJIToastResult.success("开始飞向车辆位置")) // TODO 这个 targetAlt 需要后期经过计算算出来。 navigateToTarget(vehicleLatitude, vehicleLongitude, 100.0, callback) } /** * Navigate to target location using Virtual Stick */ private fun navigateToTarget( targetLat: Double, targetLon: Double, targetAlt: Double, callback: CommonCallbacks.CompletionCallback ) { VirtualStickManager.getInstance().enableVirtualStick(object : CommonCallbacks.CompletionCallback { override fun onSuccess() { VirtualStickManager.getInstance().setVirtualStickAdvancedModeEnabled(true) isNavigating = true startNavigation(targetLat, targetLon, targetAlt, callback) } override fun onFailure(error: IDJIError) { callback.onFailure(error) } }) } /** * Start navigation loop using Virtual Stick */ private fun startNavigation( targetLat: Double, targetLon: Double, targetAlt: Double, callback: CommonCallbacks.CompletionCallback ) { virtualStickHandler = Handler(Looper.getMainLooper()) val navTask = object : Runnable { override fun run() { if (!isNavigating) return val currentLoc = getAircraftLocation() if (currentLoc == null) { virtualStickHandler?.postDelayed(this, 100) return } // Calculate remaining distance val remainingDistance = calculateDistance( currentLoc.latitude, currentLoc.longitude, targetLat, targetLon ) println("targetLat:" + targetLat + " targetLon:" + targetLon + " currentLoc.latitude:" + currentLoc.latitude + " currentLoc.longitude:" + currentLoc.longitude + " remainingDistance:" + remainingDistance) // Check if arrived if (remainingDistance < ARRIVAL_THRESHOLD) { // Arrived at target, stop navigation isNavigating = false virtualStickHandler?.removeCallbacksAndMessages(null) callback.onSuccess() toastResult?.postValue(DJIToastResult.success("已到达车辆位置，开始精确定位")) // 开始调节云台角度，俯仰角为 -90°，旋转时间 1s startGimbalAngleRotation(GimbalAngleRotationMode.ABSOLUTE_ANGLE, -90.0, 0.0, 0.0, 1.0) // Start precision adjustment startDynamicAdjustment() } else { // Continue navigation val bearing = calculateBearing( currentLoc.latitude, currentLoc.longitude, targetLat, targetLon ) val navParam = VirtualStickFlightControlParam().apply { rollPitchCoordinateSystem = FlightCoordinateSystem.GROUND // Use ground coordinate system verticalControlMode = VerticalControlMode.POSITION yawControlMode = YawControlMode.ANGLE rollPitchControlMode = RollPitchControlMode.VELOCITY // Calculate velocity components based on bearing val bearingRad = Math.toRadians(bearing) pitch = NAVIGATION_SPEED * Math.sin(bearingRad) // North-South component roll = NAVIGATION_SPEED * Math.cos(bearingRad) // East-West component yaw = bearing // Point towards target verticalThrottle = targetAlt // Target altitude } VirtualStickManager.getInstance().sendVirtualStickAdvancedParam(navParam) virtualStickHandler?.postDelayed(this, 100) } } } virtualStickHandler?.post(navTask) } fun startGimbalAngleRotation( mode: GimbalAngleRotationMode, pitch: Double, yaw: Double, roll: Double, duration: Double ) { val rotation = GimbalAngleRotation().apply { setMode(mode) setPitch(pitch) setYaw(yaw) setRoll(roll) setDuration(duration) } KeyManager.getInstance().performAction( KeyTools.createKey(GimbalKey.KeyRotateByAngle), rotation, object : CommonCallbacks.CompletionCallbackWithParam<EmptyMsg> { override fun onSuccess(result: EmptyMsg?) { toastResult?.postValue(DJIToastResult.success("云台旋转成功")) Log.i("Gimbal", "云台旋转成功：yaw:${rotation.yaw},pitch:${rotation.pitch},roll:${rotation.roll}") } override fun onFailure(error: IDJIError) { toastResult?.postValue(DJIToastResult.failed("云台旋转失败,$error")) Log.e("Gimbal", "云台旋转失败，$error") } } ) } /** * Start dynamic position adjustment loop with adaptive descent * Adjusts position while descending, with stricter requirements at lower altitudes */ private fun startDynamicAdjustment() { isAdjusting = true virtualStickHandler = Handler(Looper.getMainLooper()) // Send adjustment commands at 10Hz val adjustTask = object : Runnable { override fun run() { if (!isAdjusting) return // TODO 获取脚本检测出的 z 轴距离 val currentAltitude = FlightControllerKey.KeyAltitude.create().get(0.0) val currentXOffsetAbs = Math.abs(xOffset) val currentYOffsetAbs = Math.abs(yOffset) // 关闭降落保护，下视避障失效 if (currentAltitude <= 5 && !downwardObstacleDisabled) { downwardObstacleDisabled = true setObstacleAvoidanceEnable(false, PerceptionDirection.DOWNWARD) } // 检查是否落地 if (currentAltitude <= 0.1) { stopLanding() return } // Get adaptive thresholds based on altitude val offsetThreshold = getOffsetThreshold(currentAltitude) val descentSpeed = getDescentSpeed(currentAltitude, currentXOffsetAbs, currentYOffsetAbs) // Log for debugging println("自动调整 - 高度:%.2fm, x 偏移:%.2fm,y 偏移:%.2fm, 阈值:%.2fm, 下降速度:%.2fm/s".format( currentAltitude, currentXOffsetAbs, currentYOffsetAbs, offsetThreshold, descentSpeed )) // Calculate adjustment parameters val adjustParam = VirtualStickFlightControlParam().apply { rollPitchCoordinateSystem = FlightCoordinateSystem.BODY verticalControlMode = VerticalControlMode.VELOCITY yawControlMode = YawControlMode.ANGULAR_VELOCITY rollPitchControlMode = RollPitchControlMode.ANGLE // Calculate roll value based on offset // Positive offset (need to move forward) -> positive roll // Negative offset (need to move backward) -> negative roll if (currentXOffsetAbs > offsetThreshold) { // Need adjustment roll = if (xOffset > 0) ADJUSTMENT_SPEED else -ADJUSTMENT_SPEED } else { // Within threshold, no adjustment needed roll = 0.0 } if (currentYOffsetAbs > offsetThreshold) { pitch = if (yOffset > 0) ADJUSTMENT_SPEED else -ADJUSTMENT_SPEED } else { pitch = 0.0 } yaw = 0.0 verticalThrottle = -descentSpeed // Descend at adaptive speed } VirtualStickManager.getInstance().sendVirtualStickAdvancedParam(adjustParam) virtualStickHandler?.postDelayed(this, 100) } } virtualStickHandler?.post(adjustTask) toastResult?.postValue(DJIToastResult.success("开始动态位置调整")) } /** * Stop landing and cleanup */ private fun stopLanding() { virtualStickHandler?.removeCallbacksAndMessages(null) // 调用 KeyStartAutoLanding 进行停桨 FlightControllerKey.KeyStartAutoLanding.create().action( { toastResult?.postValue(DJIToastResult.success("桨叶动力关闭")) Log.i("stopLanding", "桨叶动力关闭成功") }, { toastResult?.postValue(DJIToastResult.failed("桨叶动力关闭失败")) Log.i("stopLanding", "桨叶动力关闭失败！！") } ) cleanupVirtualStick() toastResult?.postValue(DJIToastResult.success("降落完成")) } /** * Get offset threshold based on current altitude * Higher altitude allows larger offset, lower altitude requires stricter precision */ private fun getOffsetThreshold(altitude: Double): Double { return when { altitude > HIGH_ALTITUDE -> 1.0 // High altitude: allow 1m offset altitude > MID_ALTITUDE -> 0.5 // Mid altitude: allow 0.5m offset altitude > LOW_ALTITUDE -> 0.4 // Low altitude: allow 0.3m offset else -> 0.3 // Very low altitude: require 0.2m precision } } /** * Get descent speed based on current altitude and offset * Larger offset or lower altitude results in slower descent */ private fun getDescentSpeed(altitude: Double, xOffset: Double, yOffset: Double): Double { val threshold = getOffsetThreshold(altitude) return when { xOffset > threshold * 2 || yOffset > threshold * 2 -> 0.0 // Offset too large: stop descending xOffset > threshold || yOffset > threshold -> 0.1 // Offset large: slow descent altitude > MID_ALTITUDE -> 0.5 // Mid-high altitude: fast descent altitude > LOW_ALTITUDE -> 0.2 // Low altitude: slow descent else -> 0.1 // Very low altitude: very slow descent } }

基于大疆 MSDK 实现的无人机视觉引导自适应降落功能