Skip to content

Power management behaviors

Summary: The behaviors related to turning off, handling very low-battery, sleeping, and other battery-related items. (These are self-maintenance behaviors)

This note describes the power management-related behaviors. Please refer to the Technical Reference Manual for a description of Vector's internal power states, management, and sleep debt.

The main power management behaviors are launched at a very high-level. These are launched by the ModeSelector (class DispatcherStrictPriority) behavior. This behavior is invoked by:

  • InitNormalOperation behavior during start of normal behavior
  • AcousticTestMode behavior during aoustic testing at the factory
  • DevBaseBehaviorInternal behavior during start of developer mode

Power management behavior tree Figure: The power management behavior tree

The behavior file is located at:


The behavior tree system gives things in explicit priority order. The higher item in the list has more priority than the lower; when an item calls out to other nodes, all of those still have higher priority than the items lower than the original one.

The mode selector:

  • Handle powering off (the highest priority)
  • Alexa-related behaviors (not related to power management)
  • Handle overheating (in emergency mode)
  • SDK override (not related to power management)
  • Being quiet related behaviors (not related to power management)
  • Handle low battery and attempt to return to charger... if unable, turn off
  • A sleep/quiet state manager. Regular behaviors and interactions are started in this behavior tree, so are at the lowest priority.

Powering off

The highest priority behavior is the SingletonPoweringRobotOff (class PoweringRobotOff) behavior, that animates Vector while he is the process of turning off.

Name Type Value Description
powerButtonHeldToActivate_ms int 250 ms The minimum time that the power button must be held down to activate the power off sequence.
powerOnAnimName animation anim_power_offon_01 The animation to play if the button is released and Vector will resume.
powerOffAnimName animation anim_power_onoff_01 The animation to play while powering off.

Table: PoweringRobotOff configuration parameters

If the power button is released before Vector has turned off, the behavior begins the process of resuming,

The animation reference is unusual. It doesn't refer to the trigger of an animation group. Instead it refers to a specific animation.


At the opposite end -- the lowest priority -- is the SleepCycle (class SleepCycle) behavior. The behavior file is located at:


This behavior arbitrates between:

  • Vector autonomously exploring
  • Interacting with a person (outside of Alexa).
  • And going into a sleep state

If Vector has no reason to sleep, this behavior lets the CoordinateInHabitat behavior. If it decides to sleep (the decision is made in the C++ code) It initiates the FindHomeForSleeping behavior to drive to the charging dock, if possible, to sleep. (In turn it invokes MandatoryPhysicalReactions to respond to environmental hazards while driving around.)

This has a condition that keeps it in sleep, even if there is a higher priority interaction, if:

  • The battery level is low,
  • The temperature is high, or
  • Charging is stopped because it is too hot.

Depending, it will initiate the looking for home to go to sleep. This is the FindHomeForSleeping behavior.

Things that wake Vector up from the different kinds of sleep:

Sleep state Things that wake Vector
HeldInPalmSleep Being jolted, touched, picked up (out of the hand), SDK interaction, the timer, and voice commands.
LightSleep Being jolted, poked, touched, or picked up; any sound or the lights coming on; SDK interaction, the timer, and voice commands.
DeepSleep Being touched, or picked up; SDK interaction, the timer, and voice commands.

Table: That wake Vector from sleep.

This behavior includes a decision tree that sets a reason code for based on sensors that have trigger. That reason code is used above. By editting this behavior's decision tree, you can adjust how sensitive he is to conditions like touch, poking, illumination to wake him from sleep.

Note: In power save mode -- a lower sleep state -- the camera is turned off, so Vector is not sensitive to light.

Driving to the charging dock to sleep

When Vector is going into a sleep state, FindHomeForSleeping (class DispatcherStrictPriority) behavior to drive to the charging dock, if possible, to sleep. The behavior file is located at:


This behavior stops whatever else is going on, and runs a subset of navigation and driving related behaviors.

Emergency Mode

Emergency mode is quite complex, and handles conditions where:

  • The battery level is low,
  • The temperature is high, or
  • Charging is stopped because it is too hot.

The way to exit emgency mode is for the battery level to rise above the low threshold, and for temperature to cool below the hot threshold.

This is controlled by the EmergencyMode (class DispatcherQueue) behavior.

Emergency mode Figure: The emergency behavior tree

The behavior file is located at:


Animation feedback

The behavior coordinates with working with other social interactions, albeit in a restricted manner. If the trigger word is heard, it doesn't stream the audio to the voice server. Instead it:

  1. Plays the VC_ListeningGetIn animation, then
  2. Plays the StreamingDisabledButWithLight animation to indicate that streaming is disabled, and filly
  3. Sends the Play__Robot_Vic_Sfx__Wake_Word_On audio event to play a feedback sound.
  4. It also links with the following animation to show the reason why

Emergency mode uses the EmergencyModeAnimDispatcher (class DispatcherQueue) behavior to play different animations based on the the emergency condition:

  • If the battery is low, it will trigger the ChargerDockingSorryButLowBattery animation.
  • If the temperature is high, or too hot charge, it will trigger the HighTemperatureWarningFace animation; this will play the face_powersavemode sprite sequence.

The behavior file is located at:


If Vector is in picked up, or otherwise off his treads (but not being held), he plays the ChargerDockingRequestPickup animation. This is done in the EmergencyModeInAir behavior. The behavior file is located at:


Returning to the charging dock

There are a couple of behaviors that try to cause Vector to drive back to the charging dock. These run a subset of navigation and driving related behaviors to drive to the charging dock. The first is the EmergencyModeOffCharger (class DispatcherStrictPriority). The behavior file is located at:


The second is the QuietModeEmergencyModeGoHome (class DispatcherStrictPriority), which would be invoked while in quiet mode. Commentary: This behavior appears like it should not run; the same conditions that would trigger it would also trigger the much higher priority EmergencyMode behavior. This behavior should be checked out and considered for removal.

Change history synopsis

Date Change
2020-11-30 Created
2020-12-1 Quiet mode's emergency mode, and trigger word animation