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How does an S3 Slow to Safe Stop Unit slow down?

This article explains how slow to safe stop units function.

1. The S3 STSS (Slow to Safe Stop) has the capability to lower the speed limit of the vehicle on detecting a Pedestrian or Obstacle (as per your defined configurations) and automatically slows down the vehicle gradually to a safe stop.

2. The S3 uses machine vision to differentiate between pedestrians and other types of obstacles. Any physical object that is not a pedestrian is treated as a generic obstacle. As a user, you may turn on or off pedestrian and/or obstacle detection.

3. The S3 enhances safety with up to 4-sensors for sensing in all 4 directions, however there are certain constraints. Left and right side along with forks-side sensors can only detect pedestrians, also the fork-sides sensor does not go up and down with fork. The rear (back) sensor can be configured for both pedestrians and obstacles.

4. When the technician installs an S3 Slow to Safe Stop unit, he/she will configure detection zones for pedestrian, obstacles and stopping. Along with these detection zones, the technician will also configure a slow down speed corresponding to each zone. When a particular zone triggers a detection, the S3 unit will correspondingly apply the right speed limit to the vehicle.

There are four different configurable speed limits set by the technician onsite during the install and cannot be changed by an individual post the install.

These 4 speed limits are:

a. Top Speed (maximum speed when nothing is detected)

b. Object Speed (a speed limit corresponding to when a non human obstacle is detected)

c. Human Speed (a speed limit corresponding to when a pedestrian is detected)

d. Stop Speed (zero or creep speed corresponding to when an object is extremely close to the vehicle)

As an example, the image below shows the view of detection zones with default settings on a sit down forklift with a side view.


For more details on speed configuration, refer the article here https://support.siera.ai/kb/how-can-the-speeds-be-configured.

5. As a user, you can configure the slow down trigger settings (eg., pedestrian vs. obstacle detection zones) from the dashboard. The below article is for your reference on how to change the distance settings.