SoftBank Robotics documentation What's new in NAOqi 2.8?

Fall manager

NAOqi Motion - Overview | API

What it does

Because the robot may fall, we taught him to stand up. But we went even further by establishing a system to detect falls: it protects with her ​​arms before touching the ground. The robot can therefore fall, he will not hurt.

By default, the fall manager is active on the robot.

How it works

The basic idea is to look at both the support polygon and the Center Of Mass (COM) of the robot. If the COM is detected out of the support polygon, the fall manager process is activated.

This process has priority over all other motion tasks. The chosen strategy is composed by an arms and pelvis joint configuration to protect the robot follow by a stiffness off command to cushion the fall. The joint configuration depends on the fall angle (back, front, right or left).

Memory events called ALMotion/RobotIsFalling() and robotHasFallen() are raised when the fall management process starts and finishes, respectively.

Getting started

When the reflex is active

The fall manager reflex is only activated when at least one foot touch the ground (based on ALFsr).

If the robot is lift, sit or other posture than stand, the fall manager is not activated.

How to disable this reflex

As this reflex increases a lot the life time before failure of the robot, we recommend to not disable this reflex.

But as we know that in some situation, this reflex will disturb your work, it is possible to disable it using ALMotionProxy::setFallManagerEnabled method.