RobotState descriptor gives you access to sensor data—camera images, odometry, maps, and more. Declared state is automatically updated at 50Hz while your skill runs.
Declaration
Declare state dependencies as class attributes:from brain_client.skill_types import Skill, RobotState, RobotStateType
class MySkill(Skill):
image = RobotState(RobotStateType.LAST_MAIN_CAMERA_IMAGE_B64)
odom = RobotState(RobotStateType.LAST_ODOM)
None on first access.
Available State
| State | Type Enum | Description |
|---|---|---|
| Camera Image | RobotStateType.LAST_MAIN_CAMERA_IMAGE_B64 | Latest frame (base64 JPEG). |
| Odometry | RobotStateType.LAST_ODOM | Position, orientation, and velocity. |
| Map | RobotStateType.LAST_MAP | Occupancy grid. |
| Head Position | RobotStateType.LAST_HEAD_POSITION | Head tilt angle. |
Camera Image
The main camera image as a base64-encoded JPEG:class MySkill(Skill):
image = RobotState(RobotStateType.LAST_MAIN_CAMERA_IMAGE_B64)
def execute(self):
if not self.image:
return "No image available", SkillResult.FAILURE
# Decode base64 to bytes
import base64
image_bytes = base64.b64decode(self.image)
# Use with PIL
from PIL import Image
import io
img = Image.open(io.BytesIO(image_bytes))
# Or send to vision API
response = vision_api.analyze(self.image)
Odometry
Current position, orientation, and velocity:class MySkill(Skill):
odom = RobotState(RobotStateType.LAST_ODOM)
def execute(self):
if self.odom:
x = self.odom.pose.pose.position.x
y = self.odom.pose.pose.position.y
# orientation as quaternion
qz = self.odom.pose.pose.orientation.z
qw = self.odom.pose.pose.orientation.w
Map
The occupancy grid map:class MySkill(Skill):
map_data = RobotState(RobotStateType.LAST_MAP)
def execute(self):
if self.map_data:
width = self.map_data.info.width
height = self.map_data.info.height
resolution = self.map_data.info.resolution
data = self.map_data.data # 1D array of occupancy values
Head Position
Current head tilt angle:class MySkill(Skill):
head_pos = RobotState(RobotStateType.LAST_HEAD_POSITION)
def execute(self):
if self.head_pos:
current_angle = self.head_pos
# Returns int: -25 to +15
Example: CaptureImages
A skill that captures images while rotating:from brain_client.skill_types import (
Skill, SkillResult, Interface, InterfaceType, RobotState, RobotStateType
)
import math
class CaptureImages(Skill):
mobility = Interface(InterfaceType.MOBILITY)
image = RobotState(RobotStateType.LAST_MAIN_CAMERA_IMAGE_B64)
@property
def name(self):
return "capture_images"
def guidelines(self):
return "Use to capture images from multiple directions."
def execute(self, num_directions: int = 4):
images = []
rotation_step = (2 * math.pi) / num_directions
for i in range(num_directions):
if self._cancelled:
return "Capture cancelled", SkillResult.CANCELLED
# Capture current frame
if self.image:
images.append(self.image)
self._send_feedback(f"Captured {i+1}/{num_directions}")
# Rotate to next position
if i < num_directions - 1:
self.mobility.rotate(rotation_step)
return f"Captured {len(images)} images", SkillResult.SUCCESS
def cancel(self):
self._cancelled = True
return "Capture cancelled"
Example: MonitorPosition
A skill that tracks robot movement:from brain_client.skill_types import Skill, SkillResult, RobotState, RobotStateType
import math
import time
class MonitorPosition(Skill):
odom = RobotState(RobotStateType.LAST_ODOM)
@property
def name(self):
return "monitor_position"
def guidelines(self):
return "Use to monitor robot position for a duration."
def execute(self, duration: float = 5.0):
if not self.odom:
return "Odometry not available", SkillResult.FAILURE
start_x = self.odom.pose.pose.position.x
start_y = self.odom.pose.pose.position.y
start_time = time.time()
while time.time() - start_time < duration:
if self._cancelled:
return "Monitoring cancelled", SkillResult.CANCELLED
x = self.odom.pose.pose.position.x
y = self.odom.pose.pose.position.y
distance = math.sqrt((x - start_x)**2 + (y - start_y)**2)
self._send_feedback(f"Moved {distance:.2f}m from start")
time.sleep(0.5)
return f"Monitoring complete", SkillResult.SUCCESS
def cancel(self):
self._cancelled = True
return "Monitoring cancelled"