The system relies on optical detection principals and may not work in all situations
and environments.
A shear event can occur when the platform is in drive mode and the operator is struck by a stationary object. This
event is detected based off the operator’s acceleration, velocity and current position. The direction of the
operator’s movement is opposite to the movement of the platform.
For example:
If driving forward, the operator
can move forward to look over the front of the platform when driving, and when driving forward, if a shear event
occurs, the object would push the operator backwards. If the operator is driving backwards, a shear event would
push the operator forward towards the control box.
If a shear event is detected, the machine cutout will be applied, and the operator will be prevented from driving
the machine. The system will then announce “Cutout”. The operator can always regain control of the machine by
moving back into the correct working position or by applying the system override to move out of the dangerous
situation. Since the OverWatch™ only applies the cutout to the upper control panel, the lower panel can be used
at any time to take control of the machine and lower the platform.
In the situation where a shear event has been detected, and the OverWatch has sensed that the operator has
not moved position within 5 seconds; the OverWatch calculates that the operator may be pinned, stuck or
incapacitated. As with a crush event and subsequent pinning of the operator, the OverWatch will sound the
machine’s horn 3 times every 10 seconds. This is to alert surrounding workers about the situation, so that they
may assist where required. If the operator releases and then presses the joystick trigger, the OverWatch determines that the operator is not incapacitated and is able to control the machine and cancels the horn alert.
The OverWatch only applies the cutout to the upper control panel, the lower panel can be used at
any time to take control of the machine and lower the platform.