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Drive Modes (Differential Rover)

Flight modes (or more accurately "Drive modes" for ground vehicles) provide autopilot support to make it easier to manually drive the vehicle or to execute autonomous missions.

This section outlines all supported drive modes for differential rovers.

For information on mapping RC control switches to specific modes see: Basic Configuration > Flight Modes.

WARNING

Selecting any other mode than those listed below will either stop the rover or can lead to undefined behaviour.

Manual Modes

Manual modes require stick inputs from the user to drive the vehicle.

Manual Controls

The manual modes listed below provide increasing levels of autopilot support:

ModeForward speedYaw rateRequired measurements
ManualDirectly map stick input to motor commands.Directly map stick input to motor commands.None.
AcroDirectly map stick input to motor commands.Stick input creates a yaw rate setpoint for the control system to regulate.Yaw rate.
StabilizedDirectly map stick input to motor commands.Stick input creates a yaw rate setpoint for the control system to regulate. If this setpoint is zero (stick is centered) the control system will maintain the current yaw (heading) of the rover.Yaw rate and yaw.
PositionStick input creates a speed setpoint for the control system to regulate.Stick input creates a yaw rate setpoint for the control system to regulate. If this setpoint is zero (stick is centered) the control system will keep the rover driving in a straight line.Yaw rate, yaw, speed and global position (GPS).

수동 모드

In this mode the stick inputs are directly mapped to motor commands. The rover does not attempt to maintain a specific orientation or compensate for external factors like slopes or uneven terrain! The user is responsible for making the necessary adjustments to the stick inputs to keep the rover on the desired course.

StickEffect
Left stick up/downDrive the rover forwards/backwards.
Left stick centeredZero forward speed input.
Right stick left/rightYaw the rover to the left/right.
Right stick centeredZero yaw rate input

For the configuration/tuning of this mode see Manual mode.

Acro Mode

INFO

This mode requires a yaw rate measurement.

In this mode the vehicle regulates its yaw rate to a setpoint (but does not stabilize heading or regulate speed).

StickEffect
Left stick up/downDrive the rover forwards/backwards.
Left stick centeredZero forward speed input.
Right stick left/rightCreate a yaw rate setpoint for the control system to regulate.
Right stick centeredThe control system will attempt to maintain a zero yaw rate (minimal disturbance rejection)

For the configuration/tuning of this mode see Acro mode.

Stabilized Mode

INFO

This mode requires a yaw rate and yaw estimate.

In this mode the vehicle regulates its yaw rate to a setpoint and will maintain its heading if this setpoint is zero (but does not regulate speed). Compared to Acro mode, this mode is much better at driving in a straight line as it can more effectively reject disturbances.

StickEffect
Left stick up/downDrive the rover forwards/backwards.
Left stick centeredZero forward speed input.
Right stick left/rightCreate a yaw rate setpoint for the control system to regulate.
Right stick centeredThe control system will maintain the current heading.

For the configuration/tuning of this mode see Stabilized mode.

Position Mode

INFO

This mode requires a yaw rate, yaw, speed and global position estimate.

This is the manual mode with the most autopilot support. The vehicle regulates its yaw rate and speed to a setpoint. If the yaw rate setpoint is zero, the controller will remember the GNSS coordinates and yaw (heading) of the vehicle and use those to construct a line that the rover will then follow (course control). This offers the highest amount of disturbance rejection, which leads to the best straight line driving behavior.

StickEffect
Left stick up/downCreate a speed setpoint for the control system to regulate.
Left stick centeredZero forward speed input.
Right stick left/rightCreate a yaw rate setpoint for the control system to regulate.
Right stick centeredThe control system will maintain the course of the rover.

For the configuration/tuning of this mode see Position mode.

Auto Modes

In auto modes the autopilot takes over control of the vehicle to run missions, return to launch, or perform other autonomous navigation tasks. For the configuration/tuning of these modes see Auto Modes.

Mission Mode

Mission mode is an automatic mode in which the vehicle executes a predefined autonomous mission plan that has been uploaded to the flight controller. The mission is typically created and uploaded with a Ground Control Station (GCS) application, such as QGroundControl.

Mission commands

The following commands can be used in missions at time of writing (main(PX4 v1.16+)):

QGC mission item통신설명
Mission startMAV_CMD_MISSION_STARTStarts the mission.
WaypointMAV_CMD_NAV_WAYPOINTNavigate to waypoint.
Return to launchMAV_CMD_NAV_RETURN_TO_LAUNCHReturn to the launch location.
Delay untilMAV_CMD_NAV_DELAYThe rover will stop for a specified amount of time.
Change speedMAV_CMD_DO_CHANGE_SPEEDChange the speed setpoint
Set launch locationMAV_CMD_DO_SET_HOMEChanges launch location to specified coordinates.
Jump to item (all)MAV_CMD_DO_JUMP (and other jump commands)Jump to specified mission item.
Loiter (all)MAV_CMD_NAV_LOITER_TIME (and other loiter commands)Stop the rover for given time. Other commands stop indefinitely.

Return Mode

This mode uses the pure pursuit guidance logic with the launch position as goal. Return mode can be activated through the respective mission command or through the ground station UI.