viam.components.base.base

Module Contents

Classes

Base	Base represents a physical base of a robot.

class viam.components.base.base.Base(name: str)

Bases: viam.components.component_base.ComponentBase

Base represents a physical base of a robot.

This acts as an abstract base class for any drivers representing specific base implementations. This cannot be used on its own. If the __init__() function is overridden, it must call the super().__init__() function.

from viam.components.base import Base

class Properties

width_meters: float

turning_radius_meters: float

wheel_circumference_meters: float

SUBTYPE: Final

abstract async move_straight(distance: int, velocity: float, *, extra: Dict[str, Any] | None = None, timeout: float | None = None, **kwargs)

Move the base in a straight line the given distance, expressed in millimeters, at the given velocity, expressed in millimeters per second. When distance or velocity is 0, the base will stop. This method blocks until completed or cancelled.

my_base = Base.from_robot(robot=robot, name="my_base")

# Move the base 40 mm at a velocity of 90 mm/s, forward.
await my_base.move_straight(distance=40, velocity=90)

# Move the base 40 mm at a velocity of -90 mm/s, backward.
await my_base.move_straight(distance=40, velocity=-90)

Parameters:

• distance (int) – The distance (in millimeters) to move. Negative implies backwards.

• velocity (float) – The velocity (in millimeters per second) to move. Negative implies backwards.

abstract async spin(angle: float, velocity: float, *, extra: Dict[str, Any] | None = None, timeout: float | None = None, **kwargs)

Spin the base in place angle degrees, at the given angular velocity, expressed in degrees per second. When velocity is 0, the base will stop. This method blocks until completed or cancelled.

my_base = Base.from_robot(robot=robot, name="my_base")

# Spin the base 10 degrees at an angular velocity of 15 deg/sec.
await my_base.spin(angle=10, velocity=15)

Parameters:

• angle (float) – The angle (in degrees) to spin.

• velocity (float) – The angular velocity (in degrees per second) to spin. Given a positive angle and a positive velocity, the base will turn to the left.

abstract async set_power(linear: viam.components.base.Vector3, angular: viam.components.base.Vector3, *, extra: Dict[str, Any] | None = None, timeout: float | None = None, **kwargs)

Set the linear and angular velocity of the Base When linear is 0, the the base will spin. When angular is 0, the the base will move in a straight line. When both linear and angular are 0, the base will stop. When linear and angular are both nonzero, the base will move in an arc, with a tighter radius if angular power is greater than linear power.

my_base = Base.from_robot(robot=robot, name="my_base")

# Make your wheeled base move forward. Set linear power to 75%.
print("move forward")
await my_base.set_power(
    linear=Vector3(x=0, y=-.75, z=0),
    angular=Vector3(x=0, y=0, z=0))

# Make your wheeled base move backward. Set linear power to -100%.
print("move backward")
await my_base.set_power(
    linear=Vector3(x=0, y=-1.0, z=0),
    angular=Vector3(x=0, y=0, z=0))

# Make your wheeled base spin left. Set angular power to 100%.
print("spin left")
await my_base.set_power(
    linear=Vector3(x=0, y=0, z=0),
    angular=Vector3(x=0, y=0, z=1))

# Make your wheeled base spin right. Set angular power to -75%.
print("spin right")
await my_base.set_power(
    linear=Vector3(x=0, y=0, z=0),
    angular=Vector3(x=0, y=0, z=-.75))

Parameters:

• linear (Vector3) – The linear component. Only the Y component is used for wheeled base. Positive implies forwards.

• angular (Vector3) – The angular component. Only the Z component is used for wheeled base. Positive turns left; negative turns right.

abstract async set_velocity(linear: viam.components.base.Vector3, angular: viam.components.base.Vector3, *, extra: Dict[str, Any] | None = None, timeout: float | None = None, **kwargs)

Set the linear and angular velocities of the base.

my_base = Base.from_robot(robot=robot, name="my_base")

# Set the linear velocity to 50 mm/sec and the angular velocity to
# 15 degree/sec.
await my_base.set_velocity(
    linear=Vector3(x=0, y=50, z=0), angular=Vector3(x=0, y=0, z=15))

Parameters:

• linear (Vector3) – Velocity in mm/sec

• angular (Vector3) – Velocity in deg/sec

abstract async stop(*, extra: Dict[str, Any] | None = None, timeout: float | None = None, **kwargs)

Stop the base.

my_base = Base.from_robot(robot=robot, name="my_base")

# Move the base forward 10 mm at a velocity of 50 mm/s.
await my_base.move_straight(distance=10, velocity=50)

# Stop the base.
await my_base.stop()

abstract async is_moving() → bool

Get if the base is currently moving.

my_base = Base.from_robot(robot=robot, name="my_base")

# Check whether the base is currently moving.
moving = await my_base.is_moving()
print('Moving: ', moving)

Returns:

Whether the base is moving.

Return type:

bool

abstract async get_properties(*, timeout: float | None = None, **kwargs) → Properties

Get the base width and turning radius

my_base = Base.from_robot(robot=robot, name="my_base")

# Get the width and turning radius of the base
properties = await my_base.get_properties()

# Get the width
print(f"Width of base: {properties.width_meters}")

# Get the turning radius
print(f"Turning radius of base: {properties.turning_radius_meters}")

# Get the wheel circumference
print(f"Wheel circumference of base: {properties.wheel_circumference_meters}")

Returns:

The properties of the base

Return type:

Properties

classmethod from_robot(robot: viam.robot.client.RobotClient, name: str) → typing_extensions.Self

Get the component named name from the provided robot.

Parameters:

• robot (RobotClient) – The robot

• name (str) – The name of the component

Returns:

The component, if it exists on the robot

Return type:

Self

abstract async do_command(command: Mapping[str, ValueTypes], *, timeout: float | None = None, **kwargs) → Mapping[str, ValueTypes]

Send/Receive arbitrary commands to the Resource

command = {"cmd": "test", "data1": 500}
result = component.do(command)

Parameters:

command (Mapping[str, ValueTypes]) – The command to execute

Raises:

NotImplementedError – Raised if the Resource does not support arbitrary commands

Returns:

Result of the executed command

Return type:

Mapping[str, ValueTypes]

async get_geometries(*, extra: Dict[str, Any] | None = None, timeout: float | None = None) → List[viam.proto.common.Geometry]

Get all geometries associated with the Component, in their current configuration, in the frame of the Component.

geometries = await component.get_geometries()

if geometries:
    # Get the center of the first geometry
    print(f"Pose of the first geometry's centerpoint: {geometries[0].center}")

Returns:

The geometries associated with the Component.

Return type:

List[Geometry]

classmethod get_resource_name(name: str) → viam.proto.common.ResourceName

Get the ResourceName for this Resource with the given name

# Can be used with any resource, using an arm as an example
my_arm_name = my_arm.get_resource_name("my_arm")

Parameters:

name (str) – The name of the Resource

Returns:

The ResourceName of this Resource

Return type:

ResourceName

get_operation(kwargs: Mapping[str, Any]) → viam.operations.Operation

Get the Operation associated with the currently running function.

When writing custom resources, you should get the Operation by calling this function and check to see if it’s cancelled. If the Operation is cancelled, then you can perform any necessary (terminating long running tasks, cleaning up connections, etc. ).

Parameters:

kwargs (Mapping[str, Any]) – The kwargs object containing the operation

Returns:

The operation associated with this function

Return type:

viam.operations.Operation

async close()

Safely shut down the resource and prevent further use.

Close must be idempotent. Later configuration may allow a resource to be “open” again. If a resource does not want or need a close function, it is assumed that the resource does not need to return errors when future non-Close methods are called.

await component.close()