Fall manager ¶
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).
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, please follow these two steps to disable it.
The first step is to allow deactivation of this reflex:
Disable the reflex
Once the deactivation of the fall manager is allowed, it’s possible to use the ALMotionProxy::setFallManagerEnabled() method to disable the fall manager for the current NAOqi launch.
Before this, you should have prepared your own defensive methods to protect from falls.
You can also use the ALMotion preference key “ENABLE_FALL_MANAGER_PROTECTION” with a value=”false” for disable at every NAOqi launch the fall manager reflex.
And the preference file should have this form: