Drive Manager

Drive Manager#

DriveManager is responsible for direct control communication with the robot. It is used to perform last checks on any control command before passing it to the robot to ensure that the commands falls within the robot control limits, satisfies smoothness conditions and does not lead to a collision with a nearby obstacle.

The DriveManager component can perform one or multiple of the following functionalities based on the desired config:

Control limiting

Checks that the incoming control is within the robot control limits. If a control command is outside the robot control limits, the DriveManager limits the value to the maximum/minimum allowed value before passing the command to the robot

Emergency stopping

Checks the direct sensor information from the configured proximity sensors and performs an emergency stop if an obstacle is closer than the allowed safety limit

Control Smoothing (Filtering)

Performs smoothing filtering on the incoming control commands before sending the commands to the robot

Robot Unblocking

Moves the robot forward, backwards or rotates in place if the space is free to move the robot away from a blocking point. This action can be configured to be triggered with an external event

DriveManager also includes built-in movement actions used for directly control the robot or unblocking the robot in certain conditions:

Action

Function

move_forward

Moves the robot forward for max_distance meters, if the forward direction is clear of obstacles.

move_backward

Moves the robot backwards for max_distance meters, if the backward direction is clear of obstacles.

rotate_in_place

Rotates the robot in place for max_rotation radians, if the given safety margin around the robot is clear of obstacles.

move_to_unblock

Moves the robot forward, backwards or rotates in place if the space is free to move the robot away from a blocking point.

Note

All the previous movement actions require LaserScan information to determine if the movement direction is collision-free

See also

Check an example on configuring the robot unblocking functionality with an external event in this tutorial

Available Run Types#

Timed

Sends incoming command periodically to the robot

Inputs#

Key

Description

Accepted Types

Number of Topics

Default Value

command

One control command to pass to the robot

Twist

1

Topic(name="/control", msg_type="Twist")

multi_command

A set of control commands to pass to the robot

TwistArray

1

Topic(name="/control_list", msg_type="TwistArray")

sensor_data

Direct sensor input

LaserScan, Float64, Float32

1 + (10 optional)

Topic(name="/scan", msg_type="LaserScan")

location

Robot current location

Odometry, PoseWithCovariance, Pose

1

Topic(name="/odom", msg_type="Odometry")

Outputs#

Key

Description

Accepted Types

Default Value

robot_command

Robot control command

Twist

Topic(name="/cmd_vel", msg_type="Twist")

emergency_stop

Emergency stop declaration flag

Bool

Topic(name="/emergency_stop", msg_type="Bool")

Usage Example:#

    from kompass.components import DriveManager, DriveManagerConfig
    from kompass.topic import Topic

    # Setup custom configuration
    # cmd_rate: rate for sending commands to the robot (Hz)
    # critical_zone_distance: for emergency stp (m)
    my_config = DriveManagerConfig(cmd_rate=10.0, critical_zone_distance=0.05)

    driver = DriveManager(component_name="driver", config=my_config)

    # Change the robot command output
    driver.outputs(robot_command=Topic(name='/my_robot_cmd', msg_type='Twist'))
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