Aldebaran documentation What's new in NAOqi 2.4.3?

Slope compensation

ALMotion - Overview

juju Pepper only

What it does

The Slope compensation is a reflex dedicated to prevent the fall of the robot when it is or goes on a slope.

The principle is to compensate the slope angle using information provided by its accelerometers and wheel velocities.

When a slope is detected:

  • The posture is automatically adapted in order to remain upright.
  • The Stiffness of the wheels is set to 1 so that the robot does not slide down the slope.

How it works

The Slope compensation reflex is enabled by default when NAOqi is running.

Related events:

  • ALMotion/Safety/RobotOnASlope() is sent when the robot has detected, or no longer detects a slope. The value is set at True if a slope is detected, False in the other case.

Performances and Limitations

  • The robot can reach a slope of a maximum angle of 5° without falling.
  • If the slope angle is too high, the robot can fall, and in that case the Fall manager will be triggered.
  • The Stiffness of the wheels will remain set to 1 even if the robot is in rest with the brakes activated. This implies that the robot cannot be moved manually when it is on a slope.
  • To deactivate the Stiffness of the wheels, the Power hatch must be open. During this process, the owner of Pepper should be careful to hold the robot to prevent any fall on the slope.