# US 12,179,734 B2 · Braking actions for failing can buses for autonomous vehicles > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 12,179,734 B2 - Document ID: US12179734B2 - Status: Granted - Kind: B2 - Application number: 17/952,127 - Filed: 2022-09-23 - Published: 2024-03-28 - Granted: 2024-12-31 - Earliest claimed: 2022-09-23 - Assignees: Baidu USA LLC - Applicants: Baidu USA LLC - Inventors: Baoping Yuan; Tianjia Sun; Yaoming Shen - Web page: https://patentgrep.com/patent/US12179734B2 ## CPC - B60T 8/885: {using electrical circuitry} - B60W 30/18109: {Braking} - B60W 50/029: Adapting to failures or work around with other constraints, e.g. circumvention by avoiding use of failed parts - B60W 60/0015: {specially adapted for safety} - B60T 2201/12: Pre-actuation of braking systems without significant braking effect; Optimizing brake performance by reduction of play between brake pads and brake disc - B60T 2270/10: ABS control systems - B60T 2270/402: Back-up - B60T 2270/413: Plausibility monitoring, cross check, redundancy - B60T: VEHICLE BRAKE CONTROL SYSTEMS OR PARTS THEREOF; BRAKE CONTROL SYSTEMS OR PARTS THEREOF, IN GENERAL (electrodynamic brake systems for vehicle, in general B60L; brakes per se, i.e. devices where braking effect occurs, including ultimate brake actuators, F16D); ARRANGEMENT OF BRAKING ELEMENTS ON VEHICLES IN GENERAL; PORTABLE DEVICES FOR PREVENTING UNWANTED MOVEMENT OF VEHICLES; VEHICLE MODIFICATIONS TO FACILITATE COOLING OF BRAKES - B60W: CONJOINT CONTROL OF VEHICLE SUB-UNITS OF DIFFERENT TYPE OR DIFFERENT FUNCTION; CONTROL SYSTEMS SPECIALLY ADAPTED FOR HYBRID VEHICLES; ROAD VEHICLE DRIVE CONTROL SYSTEMS FOR PURPOSES NOT RELATED TO THE CONTROL OF A PARTICULAR SUB-UNIT ## Abstract In one embodiment, a system determines a signal fault at a communication bus of an autonomous driving vehicle (ADV). In response to determining the signal fault, the system sends a brake pre-charge command to a brake system of the ADV to pre-charge a brake of the ADV. The system determines a preset tolerance time to validate the signal fault. In response to a time elapse of the preset tolerance time, the system validates the signal fault at the communication bus or determine a signal fault at another communication bus. In response to validating the signal fault at the communication bus or determining the signal fault at the another communication bus, the system sends a brake command to the brake system of the ADV to engage brakes for the ADV. ## Claims ### Claim 1 A computer-implemented method, comprising: determining a signal fault of a communication bus at an autonomous driving vehicle (ADV); in response to determining the signal fault, sending a brake pre-charge command to a brake system of the ADV to pre-charge a brake of the ADV; determining a preset tolerance time to validate the signal fault; in response to a time elapse of the preset tolerance time, validating the signal fault of the communication bus or determining a signal fault of another communication bus; and in response to validating the signal fault of the communication bus or determining the signal fault of the another communication bus, sending a brake command to the brake system of the ADV to engage brakes for the ADV. ### Claim 2 (depends on 1) The method of claim 1, further comprising: determining that the signal fault of the communication bus is invalidated within the preset tolerance time; and in response to determining that the signal fault of the communication bus is invalidated within the preset tolerance time, sending a brake recovery command to the brake system of the ADV to release the brakes. ### Claim 3 (depends on 1) The method of claim 1, wherein the brake system is a primary brake system or a secondary brake system of the ADV, wherein the secondary brake system includes an anti-lock brake system. ### Claim 4 (depends on 1) The method of claim 1, wherein the communication bus includes a primary controller area network (CAN) or a second CAN bus, wherein a communication channel of the primary or secondary CAN bus is used by an autonomous driving system (ADS) of the ADV to communication with a chassis domain controller of the ADV. ### Claim 5 (depends on 1) The method of claim 1, wherein the signal fault indicates a communication error or a lost of communication for one or more communication channels of the communication bus. ### Claim 6 (depends on 1) The method of claim 1, wherein the sent brake pre-charge command causes a brake pad to move within a threshold distance to a corresponding rotor. ### Claim 7 (depends on 1) The method of claim 1, wherein the brake pre-charge command comprises a brake distance travel command, a brake hydraulic pressure command, or a deceleration command. ### Claim 8 (depends on 1) The method of claim 1, wherein the brake pre-charge command includes a command flag indicating the type of command value, a command value indicating a value for a pressure or a value for a master cylinder travel distance or a deceleration value, or a command status duration indicating a duration of validity of the command. ### Claim 9 (depends on 1) The method of claim 1, wherein the brake command includes a first deceleration request value corresponding to a first predetermined time period and a second deceleration request value corresponding to a second predetermined time period to minimize overshoot of deceleration from applying the brakes, wherein the first deceleration request value is greater than the second deceleration request value. ### Claim 10 (depends on 1) The method of claim 1, wherein the brake system is controlled by a drive-by-wire system. ### Claim 11 A non-transitory machine-readable medium having instructions stored therein, which when executed by a processor, cause the processor to perform operations, the operations comprising: determining a signal fault at a communication bus of an autonomous driving vehicle (ADV); in response to determining the signal fault, sending a brake pre-charge command to a brake system of the ADV to pre-charge a brake of the ADV; determining a preset tolerance time to validate the signal fault; in response to a time elapse of the preset tolerance time, validating the signal fault at the communication bus or determining a signal fault at another communication bus; and in response to validating the signal fault at the communication bus or determining the signal fault at the another communication bus, sending a brake command to the brake system of the ADV to engage brakes for the ADV. ### Claim 12 (depends on 11) The machine-readable medium of claim 11, wherein the operations further comprise: determining that the signal fault at the communication bus is invalidated within the preset tolerance time; and in response to determining that the signal fault at the communication bus is invalidated within the preset tolerance time, sending a brake recovery command to the brake system of the ADV to release the brakes. ### Claim 13 (depends on 11) The machine-readable medium of claim 11, wherein the brake system is a primary brake system or a secondary brake system of the ADV, wherein the secondary brake system includes an anti-lock brake system. ### Claim 14 (depends on 11) The machine-readable medium of claim 11, wherein the communication bus includes a primary controller area network (CAN) or a second CAN bus, wherein a communication channel of the primary or secondary CAN bus is used by an autonomous driving system (ADS) of the ADV to communication with a chassis domain controller of the ADV. ### Claim 15 (depends on 11) The machine-readable medium of claim 11, wherein the signal fault indicates a communication error or a lost of communication for one or more communication channels of the communication bus. ### Claim 16 A data processing system, comprising: a processor; and a memory coupled to the processor to store instructions, which when executed by the processor, cause the processor to perform operations, the operations including determining a signal fault at a communication bus of an autonomous driving vehicle (ADV); in response to determining the signal fault, sending a brake pre-charge command to a brake system of the ADV to pre-charge a brake of the ADV; determining a preset tolerance time to validate the signal fault; in response to a time elapse of the preset tolerance time, validating the signal fault at the communication bus or determining a signal fault at another communication bus; and in response to validating the signal fault at the communication bus or determining the signal fault at the another communication bus, sending a brake command to the brake system of the ADV to engage brakes for the ADV. ### Claim 17 (depends on 16) The system of claim 16, wherein the operations further comprise: determining that the signal fault at the communication bus is invalidated within the preset tolerance time; and in response to determining that the signal fault at the communication bus is invalidated within the preset tolerance time, sending a brake recovery command to the brake system of the ADV to release the brakes. ### Claim 18 (depends on 16) The system of claim 16, wherein the brake system is a primary brake system or a secondary brake system of the ADV, wherein the secondary brake system includes an anti-lock brake system. ### Claim 19 (depends on 16) The system of claim 16, wherein the communication bus includes a primary controller area network (CAN) or a second CAN bus, wherein a communication channel of the primary or secondary CAN bus is used by an autonomous driving system (ADS) of the ADV to communication with a chassis domain controller of the ADV. ### Claim 20 (depends on 16) The system of claim 16, wherein the signal fault indicates a communication error or a lost of communication for one or more communication channels of the communication bus.