Patent ID: 11921484
Assignee: AMAZON TECHNOLOGIES, INC.
Field: Control (Instruments)
Classification: CPC G  B | IPC B  G

Claim 11:
12. A motor controller, comprising:
a programmable logic device comprising first and second modules and configured for communication with first and second sensors that are positioned on a motor comprising a motorized wheel to propel a mobile drive unit, the first and second sensors being homogeneous non-safety rated sensors, each of the first and second modules configured to:
receive, from the first and second sensors, first and second data associated with the motor; and
process the first and second data, the processing of the first and second data comprising determining a first set of characteristics associated with the motor,
wherein the programmable logic device is configured to generate a fault status responsive to comparing the first set of characteristics processed by the first module with the first set of characteristics processed by the second module; and

a safety controller comprising first and second processors, each of the first and second processors in communication with the programmable logic device and configured to:
receive, from the programmable logic device, the fault status and the first and second data associated with the motor; and
process the first and second data, the processing of the first and second data comprising determining a second set of characteristics associated with the motor,
wherein the safety controller is configured to generate operating instructions based on the fault status and comparing the second set of characteristics processed by the first processor with the second set of characteristics processed by the second processor, the operating instructions comprising data associated with the operation of the motor to control movements via the wheel of the mobile drive unit within the warehouse environment; and

a motor safety actuation controller configured to:
receive the operating instructions from the safety controller and navigating instructions from a non-safety subsystem;
prioritize the operating instructions from the safety controller that are based on the compared first and second outputs of the safety controller and the fault message from the programmable logic device; and
actuate, based on the prioritizing, the motor to safely guide the mobile drive unit while lifting an inventory holder and/or around the inventory holders within the warehouse environment.