DJI Mobile SDK Documentation

      class DJIActiveTrackMissionOperator

      @interface DJIActiveTrackMissionOperator : NSObject
      Header:DJIActiveTrackMissionOperator.h
      Inherits From:NSObject
      Description:

      The active track mission operator is the only object that controls, runs and monitors ActiveTrack Missions. It can be accessed from DJIMissionControl.

      An ActiveTrack Mission allows an aircraft to track a moving subject using the vision system and without a GPS tracker on the subject. To use an ActiveTrack mission:

      • Prepare a mission with the rectangle that best represents the target to track
      • Start the mission to initiate tracking of the object and begin the state updates (DJIMissionProgressStatus)
      • At this point, the aircraft will track the target while hovering in place.
      • Give confirmation that the tracked target is correct with acceptConfirmationWithCompletion and the aircraft will begin flying relative to the target.
      • If the tracking algorithm looses sufficient confidence in tracking the target, then the aircraft will stop flying relative to the object and either notify the user (through execution state) that the target is lost or it needs another confirmation that the target is correct.
      • If the mission is paused, the aircraft will hover in place, but continue tracking the target by adjusting gimbal pitch and aircraft yaw.
      • If mission is resumed, confirmation of tracking rectangle will need to be sent through to start flying relative to target.
      • The mission can be canceled with stopMissionWithCompletion at any time.
      • stopMissionWithCompletion should also be used to reject tracking confirmation if the camera is tracking the wrong target. After stopping the mission, the mission needs to be recreated with a new rectangle and loaded into the operator.
      • The main camera is used to track the target, so gimbal cannot be adjusted during an ActiveTrack mission.
      • During the mission the aircraft can be manually flown with pitch, roll and throttle. Yaw and gimbal are automatically controlled to continue tracking the target.
      • If the mission is executing, and after confirmation of the tracking rectangle has been sent, the aircraft can be manually controlled horizontally similar to a DJIFlightOrientationModeHomeLock where the home is the tracked target. If aircraft is manually controlled upward, the aircraft will lift and retreat, and if it is controlled downward, it will go down and get closer to the target.

      Class Members:
      Current State
      property
      property currentState
      @property (nonatomic, readonly) DJIActiveTrackMissionState currentState
      Header:DJIActiveTrackMissionOperator.h
      Description:

      The current state of the operator.

      See Also:

      DJIActiveTrackMissionState

      Check Gesture Mode Enabled
      property
      property isGestureModeEnabled
      @property (nonatomic, readonly) BOOL isGestureModeEnabled
      Header:DJIActiveTrackMissionOperator.h
      Description:

      YES if gesture mode is enabled. Value is undefined if the currentState is one of the following:

      Check Auto Sensing Enabled
      property
      property isAutoSensingEnabled
      @property (nonatomic, readonly) BOOL isAutoSensingEnabled
      Header:DJIActiveTrackMissionOperator.h
      Description:

      YES if auto sensing is enabled. Value is undefined if the currentState is one of the following:

      property isAutoSensingForQuickShotEnabled
      @property (nonatomic, readonly) BOOL isAutoSensingForQuickShotEnabled
      Header:DJIActiveTrackMissionOperator.h
      Description:

      YES if auto sensing for QuickShot is enabled. Value is undefined if the currentState is one of the following:

      Tracking Mode
      property
      property trackingMode
      @property (nonatomic, readonly) DJIActiveTrackMode trackingMode
      Header:DJIActiveTrackMissionOperator.h
      Description:

      The current tracking mode of the aircraft. It is valid when the currentState is one of the following:

      For the other states, the value is DJIActiveTrackModeUnknown.

      See Also:

      DJIActiveTrackMode

      Persistent Error
      property
      property persistentError
      @property (nonatomic, readonly, nullable) NSError *persistentError
      Header:DJIActiveTrackMissionOperator.h
      Description:

      Existing error that stops any ActiveTrack missions to start. If it is not nil, currentState will be DJIActiveTrackMissionStateCannotStart.

      method addListenerToEvents:withQueue:andBlock
      -(void)addListenerToEvents:(id)listener
      withQueue:(dispatch_queue_t)queue
      andBlock:(DJIActiveTrackMissionOperatorEventBlock)block
      Header:DJIActiveTrackMissionOperator.h
      Description:

      Adds listener to receive all the events of the ActiveTrack mission operator.

      Input Parameters:
      id listenerListener that is interested in the ActiveTrack mission operator events.
      dispatch_queue_t queueThe dispatch queue that block will be called on.
      DJIActiveTrackMissionOperatorEventBlock blockBlock will be called when there is event updated.
      Remove Listener
      method
      method removeListener
      -(void)removeListener:(id)listener
      Header:DJIActiveTrackMissionOperator.h
      Description:

      Removes listener. The listener will not receive any update after calling this method.

      Input Parameters:
      id listenerListener to be removed.
      method removeAllListeners
      -(void)removeAllListeners
      Header:DJIActiveTrackMissionOperator.h
      Description:

      Remove all listeners.

      Check Gesture Mode Supported
      method
      method isGestureModeSupported
      -(BOOL)isGestureModeSupported
      Header:DJIActiveTrackMissionOperator.h
      Description:

      Checks if the connected product supports gesture mode.

      Return:
      BOOLYES if the product supports gesture mode.
      Set Gesture Mode Enabled
      method
      method setGestureModeEnabled:withCompletion
      -(void)setGestureModeEnabled:(BOOL)enabled withCompletion:(DJICompletionBlock)completion
      Header:DJIActiveTrackMissionOperator.h
      Description:

      Enables/disables gesture mode.

      • A human subject can be automatically detected if they are moving a little (instead of requiring a defining rectangle)
      • The human subject can accept the confirmation to track them by waving their arms.
      • The tracked human can make the camera shoot a photo by showing a rectangle with their thumbs and index fingers to the aircraft.
      Gesture mode can only be enabled when the aircraft is flying but not tracking a target. The currentState should be one of the following: After the gesture mode is enabled, currentState will become DJIActiveTrackMissionStateDetectingHuman.

      Gesture mode can be disabled when currentState is not any of the following: If the aircraft is already tracking a target, disabling gesture mode will stop the ActiveTrack mission.

      Input Parameters:
      BOOL enabledYES to enable gesture mode.
      DJICompletionBlock completionCompletion block that receives the execution result.
      Check AutoSensing Supported
      method
      method isAutoSensingSupported
      - (BOOL)isAutoSensingSupported
      Header:DJIActiveTrackMissionOperator.h
      Description:

      Checks if the connected product supports auto sensing. When the product supports auto sensing, enabling auto sensing is the pre-condition of starting active track.

      Return:
      BOOLYES if the product supports auto sensing.
      Enable AutoSensing
      method
      method enableAutoSensingWithCompletion
      - (void)enableAutoSensingWithCompletion:(DJICompletionBlock)completion
      Header:DJIActiveTrackMissionOperator.h
      Description:

      Starts auto sensing. After auto sensing starts, the aircraft will sense humans captured by the camera and return the detected subjects by autoSensedSubjects in the updated event. QuickShot requires a special auto sensing mode, therefore, use enableAutoSensingForQuickShotWithCompletion if a QuickShot mission will be performed. It is only supported when isAutoSensingSupported returns YES. When the product supports auto sensing, enabling auto sensing is the pre-condition of starting active track.

      Input Parameters:
      DJICompletionBlock completionCompletion block that receives the execution result.
      method enableAutoSensingForQuickShotWithCompletion
      - (void)enableAutoSensingForQuickShotWithCompletion:(DJICompletionBlock)completion
      Header:DJIActiveTrackMissionOperator.h
      Description:

      Starts auto sensing specifically for QuickShot. After auto sensing starts, the aircraft will sense humans captured by the camera and return the detected subjects by autoSensedSubjects in the updated event. This interface is specific for QuickShot, therefore, use enableAutoSensingWithCompletion for missions other than QuickShot. It is only supported when isAutoSensingSupported returns YES. When the product supports auto sensing, enabling auto sensing is the pre-condition of starting active track.

      Input Parameters:
      DJICompletionBlock completionCompletion block that receives the execution result.
      Disable AutoSensing
      method
      method disableAutoSensingWithCompletion
      - (void)disableAutoSensingWithCompletion:(DJICompletionBlock)completion
      Header:DJIActiveTrackMissionOperator.h
      Description:

      Stops auto sensing (either for QuickShot or the other active track modes). It is only supported when isAutoSensingSupported returns YES.

      Input Parameters:
      DJICompletionBlock completionCompletion block that receives the execution result.
      Check Start Mission
      method
      method canStartMission
      -(nullable NSError *)canStartMission:(DJIActiveTrackMission *)mission
      Header:DJIActiveTrackMissionOperator.h
      Description:

      Checks if the operator can start the mission.

      Input Parameters:
      DJIActiveTrackMission * missionAn ActiveTrack mission.
      Return:
      nullable NSError *The possible error if the operator tries to start the mission.
      Start Mission
      method
      method startMission:withCompletion
      -(void)startMission:(DJIActiveTrackMission *)mission withCompletion:(DJICompletionBlock)completion
      Header:DJIActiveTrackMissionOperator.h
      Description:

      Starts to execute an ActiveTrack mission. It can only be called when the currentState is DJIActiveTrackMissionStateReadyToStart. If a mission with DJIActiveTrackModeTrace or DJIActiveTrackModeProfile is started successfully, the currentState will become one of the following:

      If a mission with DJIActiveTrackModeSpotlight or DJIActiveTrackModeSpotlightPro is started successfully, the currentState will become DJIActiveTrackMissionStateOnlyCameraFollowing.

      Input Parameters:
      DJIActiveTrackMission * missionThe ActiveTrack mission to check.
      DJICompletionBlock completionCompletion block that receives the execution result.
      method startAutoSensingMission:withCompletion
      -(void)startAutoSensingMission:(DJIActiveTrackMission *)mission withCompletion:(DJICompletionBlock)completion
      Header:DJIActiveTrackMissionOperator.h
      Description:

      Starts to execute an ActiveTrack mission after auto sensing (either for QuickShot or the other active track modes) is started. The aircraft will start to track the subject defined by subjectIndex. If auto sensing for active track modes other than QuickShot is enabled, the active track mode to start is defined by DJIActiveTrackMission's mode. quickShotMode of DJIActiveTrackMission will be ignored. If auto sensing specifically for QuickShot is enabled, The QuickShot mode to start is defined by DJIActiveTrackMission's quickShotMode. quickShotMode of DJIActiveTrackMission will be ignored.

      It can only be called when the currentState is one of the following:
      - DJIActiveTrackMissionStateAutoSensing
      - DJIActiveTrackMissionStateAutoSensingForQuickShot
      If the aircraft has high confidence about the auto-sensed subject, confirmation is not required and the state will change to DJIActiveTrackMissionStateAircraftFollowing or DJIActiveTrackMissionStateOnlyCameraFollowing (determined by the active track mode). Otherwise, the state will change to DJIActiveTrackMissionStateWaitingForConfirmation and user need to perform acceptConfirmationWithCompletion.

      Input Parameters:
      DJIActiveTrackMission * missionThe ActiveTrack mission to check.
      DJICompletionBlock completionCompletion block that receives the execution result.
      Stop Mission
      method
      method stopMissionWithCompletion
      -(void)stopMissionWithCompletion:(DJICompletionBlock)completion
      Header:DJIActiveTrackMissionOperator.h
      Description:

      Stops the executing mission. It can only be called when the currentState is one of the following:

      After a mission is stopped successfully, currentState will become DJIActiveTrackMissionStateReadyToStart or DJIActiveTrackMissionStateDetectingHuman if gesture mode is enabled.

      Input Parameters:
      DJICompletionBlock completionCompletion block that will be called when the operator succeeds or fails to stop the mission. If it fails, an error will be returned.
      Accept Confirmation
      method
      method acceptConfirmationWithCompletion
      -(void)acceptConfirmationWithCompletion:(DJICompletionBlock)completion
      Header:DJIActiveTrackMissionOperator.h
      Description:

      When the vision system is not sure the tracking rectangle is around the user's desired target, it will need confirmation before starting to fly relative to the target. The vision system will need confirmation when currentState is DJIActiveTrackMissionStateReadyToStart. targetRect of DJIActiveTrackTrackingState can be used to show the user the rectangle the vision system is using. If the user agrees the rectangle represents the target they want to track, this method can be called to start flying relative to the target.

      Input Parameters:
      DJICompletionBlock completionCompletion block that will be called when the operator succeeds or fails to accept the target. If it fails, an error will be returned.
      Stop Aircraft Following
      method
      method stopAircraftFollowingWithCompletion
      -(void)stopAircraftFollowingWithCompletion:(DJICompletionBlock)completion
      Header:DJIActiveTrackMissionOperator.h
      Description:

      Stops the aircraft from following the target and ask for user confirmation again. It can only be called when the currentState is DJIActiveTrackMissionStateAircraftFollowing. After it is called successfully, currentState will become DJIActiveTrackMissionStateWaitingForConfirmation.

      Input Parameters:
      DJICompletionBlock completionCompletion block that will be called when the operator succeeds or fails to accept the target. If it fails, an error will be returned.
      Set Circular Speed
      method
      method setCircularSpeed:withCompletion
      -(void)setCircularSpeed:(float)speed withCompletion:(DJICompletionBlock)completion
      Header:DJIActiveTrackMissionOperator.h
      Description:

      Setting a non-zero speed starts the aircraft circling the target. Speed can be set within the range [-5, 5] m/s where a positive speed is a counter-clockwise movement (when viewing from the top). Reverting the speed to 0 m/s ends the circling movement. It can only be called when the currentState is DJIActiveTrackMissionStateAircraftFollowing and trackingMode is DJIActiveTrackModeTrace.

      Input Parameters:
      float speedCircular speed to set in m/s.
      DJICompletionBlock completionCompletion block that will be called when the operation succeeds or fails. If it fails, an error will be returned.
      Get Circular Speed
      method
      method getCircularSpeedWithCompletion
      -(void)getCircularSpeedWithCompletion:(DJIFloatCompletionBlock)completion
      Header:DJIActiveTrackMissionOperator.h
      Description:

      In an ActiveTrack mission, the aircraft can be set to circle the target while following it. This method returns the circular speed of the aircraft in m/s.

      Input Parameters:
      DJIFloatCompletionBlock completionCompletion block that will be called when the operation succeeds or fails. If it fails, an error will be returned.
      Switch Mode
      method
      method switchMode:withCompletion
      -(void)switchMode:(DJIActiveTrackMode)mode withCompletion:(DJICompletionBlock)completion
      Header:DJIActiveTrackMissionOperator.h
      Description:

      Changes the ActiveTrack mode on the currently executing mission. It can only be called when the currentState is one of the following:

      If the current state is DJIActiveTrackMissionStateAircraftFollowing, stopAircraftFollowingWithCompletion should be called before switching the mode. Also, The ActiveTrack mode can only be changed when gesture mode is disabled.

      Input Parameters:
      DJIActiveTrackMode modeActive track mode to change.
      DJICompletionBlock completionCompletion block that receives the execution result.
      Recommended Configuration
      method
      method setRecommendedConfigurationWithCompletion
      -(void)setRecommendedConfigurationWithCompletion:(DJICompletionBlock)completion
      Header:DJIActiveTrackMissionOperator.h
      Description:

      Sets the recommended camera and gimbal configuration that optimizes performance for the ActiveTrack Mission in most environments.

      Input Parameters:
      DJICompletionBlock completionCompletion block that receives the execution result.
      method setRetreatEnabled:withCompletion
      -(void)setRetreatEnabled:(BOOL)enabled withCompletion:(DJICompletionBlock)completion
      Header:DJIActiveTrackMissionOperator.h
      Description:

      Enables/disable if the aircraft can retreat (fly backwards) when the target comes toward it. When it is disabled, the aircraft will not retreat and instead rotate the gimbal pitch down to track the target as it goes underneath. If the target goes beyond the gimbal's pitch stop, the target will be lost and the mission will stop.

      Input Parameters:
      BOOL enabledYES to enable retreat during ActiveTrack mission.
      DJICompletionBlock completionCompletion block that receives the execution result.
      method getRetreatEnabledWithCompletion
      -(void)getRetreatEnabledWithCompletion:(DJIBooleanCompletionBlock)completion
      Header:DJIActiveTrackMissionOperator.h
      Description:

      Determines whether retreat is enabled in ActiveTrack mission.

      Input Parameters:
      DJIBooleanCompletionBlock completionCompletion block that receives the execution result.
      typedef block DJIActiveTrackMissionOperatorEventBlock
      typedef void (^DJIActiveTrackMissionOperatorEventBlock)(DJIActiveTrackMissionEvent *event)
      Header:DJIActiveTrackMissionOperator.h
      Description:

      Block to receive the ActiveTrack operator event.

      Input Parameters:
      DJIActiveTrackMissionEvent * eventThe ActiveTrack operator event with the state change.