# US 8,847,535 B2 · System and method to determine the operating status of an electrical system having a system controller and an actuator controller > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 8,847,535 B2 - Document ID: US8847535B2 - Status: Granted - Kind: B2 - Application number: 13/291,686 - Filed: 2011-11-08 - Published: 2013-05-09 - Granted: 2014-09-30 - Earliest claimed: 2011-11-08 - Assignees: Autoliv ASP, Inc. - Applicants: Robert Duane Mills; Jeffrey Michael Carpenter - Inventors: Robert Duane Mills; Jeffrey Michael Carpenter - Web page: https://patentgrep.com/patent/US8847535B2 ## CPC - B60L 3/0023: {Detecting, eliminating, remedying or compensating for drive train abnormalities, e.g. failures within the drive train} - B60L 3/0084: {relating to control modules} - B60L 3/04: Cutting off the power supply under fault conditions (protective devices and circuit arrangements in general H01H; H02H) - G05B 19/0428: {Safety, monitoring (G05B19/0423 takes precedence)} - G05B 2219/14106: Reconfiguration of components or graceful degradation, degrade - G05B 2219/25158: Watchdog - G06F 11/0739: {in a data processing system embedded in automotive or aircraft systems} - G06F 11/0757: {by exceeding a time limit, i.e. time-out, e.g. watchdogs} - B60L: PROPULSION OF ELECTRICALLY-PROPELLED VEHICLES (arrangements or mounting of electrical propulsion units or of plural diverse prime-movers for mutual or common propulsion in vehicles B60K1/00, B60K6/20; arrangements or mounting of electrical gearing in vehicles B60K17/12, B60K17/14; preventing wheel slip by reducing power in rail vehicles B61C15/08; dynamo-electric machines H02K; control or regulation of electric motors H02P); SUPPLYING ELECTRIC POWER FOR AUXILIARY EQUIPMENT OF ELECTRICALLY-PROPELLED VEHICLES (electric coupling devices combined with mechanical couplings of vehicles B60D1/64; electric heating for vehicles B60H1/00); ELECTRODYNAMIC BRAKE SYSTEMS FOR VEHICLES IN GENERAL (control or regulation of electric motors H02P); MAGNETIC SUSPENSION OR LEVITATION FOR VEHICLES; MONITORING OPERATING VARIABLES OF ELECTRICALLY-PROPELLED VEHICLES; ELECTRIC SAFETY DEVICES FOR ELECTRICALLY-PROPELLED VEHICLES - G05B: CONTROL OR REGULATING SYSTEMS IN GENERAL; FUNCTIONAL ELEMENTS OF SUCH SYSTEMS; MONITORING OR TESTING ARRANGEMENTS FOR SUCH SYSTEMS OR ELEMENTS (systems for controlling or regulating non-electric variables G05D; systems for regulating electric or magnetic variables G05F; control devices or systems insofar as characterised by mechanical features only G05G) - G06F: ELECTRIC DIGITAL DATA PROCESSING (computer systems based on specific computational models G06N) ## Abstract A system and method to determine the operating status of an electrical system includes a system controller and an actuator controller. The system controller determines if the actuator controller is operating properly and initiates a safe mode of operation if the actuator is not operating properly. In turn, the actuator controller determines if the system controller is operating properly and initiates a safe mode of operation if the system controller is not operating properly. ## Claims ### Claim 1 A method to determine an operating status of an electrical system having a system controller configured to send commands to several actuator controllers subordinate to the system controller, each of the several actuator controllers controlling an actuator of a vehicle, the method comprising the steps of: generating a system key by the system controller for the several actuator controllers; transmitting the system key from the system controller to a respective one of the several actuator controllers; evaluating the system key by the respective one of the several actuator controllers to determine whether the system controller is operating properly or improperly; initiating a first safe mode operation upon determining by the respective one of the actuator controllers that the system controller is operating improperly, the first safe mode operation causing the respective one of the several actuator controllers to ignore all subsequent commands received from the system controller while allowing the system controller continues to send new commands to the respective one of the several actuator controller controllers; generating an actuator key by the actuator controller; transmitting the actuator key from the actuator controller to the system controller upon determining that the system controller is operating properly; comparing the actuator key by the system controller with an expected actuator key value; determining by the system controller that the actuator controller is operating improperly upon determining that the actuator key is an unexpected actuator key value; and initiating a second safe mode operation upon determining that the actuator controller is operating improperly, the second safe mode operation causing the system controller to remove power from the actuator controller. ### Claim 2 (depends on 1) The method of claim 1 further comprising the steps of: comparing, by the actuator controller, the system key with an expected system key value; and initiating the first safe mode upon determining that system key is an unexpected system key value. ### Claim 3 (depends on 1) The method of claim 1, wherein the actuator key value is based on a system rate of the actuator controller. ### Claim 4 (depends on 1) The method of claim 1, wherein the actuator key value is based on system checks of at least one logic unit of the actuator controller. ### Claim 5 (depends on 4) The method of claim 4, wherein the at least one logic unit of the actuator controller is a read only memory, a random access memory, or an arithmetic logic unit. ### Claim 6 (depends on 1) The method of claim 1, further comprising the steps of: comparing, by the system controller, a rate at which the actuator key was generated with an expected rate; and removing power from the actuator controller upon determining that the actuator key was generated at an unexpected rate. ### Claim 7 (depends on 2) The method of claim 2, further comprising the step of transmitting from the actuator controller to the system controller information regarding an operating state of the system controller. ### Claim 8 (depends on 2) The method of claim 2, wherein the system key value is based on a system rate of the system controller. ### Claim 9 (depends on 2) The method of claim 2, wherein the system key value is based on system checks of at least one logic unit of the system controller. ### Claim 10 (depends on 9) The method of claim 9, wherein the at least one logic unit of the system controller is a read only memory, a random access memory, or an arithmetic logic unit. ### Claim 11 (depends on 2) The method of claim 2, further comprising the steps of: comparing, by the actuator controller, a rate at which the system key was generated with an expected rate; and ignoring commands from the system controller by the actuator controller upon determining that the system key was generated at an unexpected rate. ### Claim 12 (depends on 11) The method of claim 11, further comprising the step of transmitting from the actuator controller to the system controller information regarding an operating state of the system controller. ### Claim 13 (depends on 2) The method of claim 2, further comprising the steps of: determining by the actuator controller if the system controller is capable of determining if the actuator key is the expected actuator key value; and ignoring commands from the system controller by the actuator controller upon determining that the system controller is incapable of determining if the actuator key is the expected actuator key value. ### Claim 14 (depends on 1) The method of claim 1, further comprising the steps of: determining by the system controller if the actuator controller is capable of determining if the system key is the expected system key value; and removing power from the actuator controller upon determining that the actuator controller is incapable of determining if the system key is the expected system key value.