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

Claim 4:
5. A computer-implemented method, comprising:
receiving, from first and second sensors positioned on a motor coupled to a motorized wheel to control movements of a mobile drive unit, first and second data associated with the motor, the first and second data received by a programmable logic device, the first and second sensors being homogeneous non-safety rated sensors;
processing, using first and second modules of the programmable logic device, the first and second data by determining a first set of characteristics associated with the motor;
generating, using a comparison module of the programmable logic device, a fault status by comparing the first set of characteristics processed by the first module with the first set of characteristics processed by the second module;
receiving, from the programmable logic device, the first and second data associated with the motor and the fault status, the data received by a safety controller;
processing, using a first processor and a second processor of the safety controller, the first and second data of the safety controller by determining a second set of characteristics associated with the motor, each of the first and second processors processing the first and second data to determine the second set of characteristics associated with the motor;
generating, using the safety controller, operating instructions based on the fault status and by comparing the second set of characteristics determined by the first processor with the second set of characteristics determined by the second processor, the operating instructions configured to control movements of the mobile drive unit within the warehouse environment;
receiving, using a motor safety actuation controller, the operating instructions from the safety controller and navigating instructions for guiding the mobile drive unit within the warehouse environment from a non-safety subsystem;
prioritize, using a motor safety actuation controller, 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.