# US 10,118,639 B2 · Method and system for steering control of an autonomous vehicle using proportional, integral, and derivative (PID) controller > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 10,118,639 B2 - Document ID: US10118639B2 - Status: Granted - Kind: B2 - Application number: 15/316,490 - Filed: 2016-11-24 - Published: 2018-07-05 - Granted: 2018-11-06 - Earliest claimed: 2016-11-24 - Assignees: Baidu USA LLC - Applicants: Baidu USA LLC - Inventors: Fan Zhu; Qi Kong; Xiang Yu; Sen Hu; Qi Luo; Zhenguang Zhu; Yuchang Pan; Wenli Yang; Guang Yang; Jingao Wang - Web page: https://patentgrep.com/patent/US10118639B2 ## CPC - B62D 6/002: {computing target steering angles for front or rear wheels (B62D7/159 takes precedence)} - B62D 6/02: responsive only to vehicle speed - B62D 15/025: {Active steering aids, e.g. helping the driver by actively influencing the steering system after environment evaluation (B62D1/28 takes precedence)} - B62D 15/0265: {Automatic obstacle avoidance by steering} - G05B 19/402: characterised by control arrangements for positioning, e.g. centring a tool relative to a hole in the workpiece, additional detection means to correct position (G05B19/19 takes precedence) - G05B 2219/42033: Kind of servo controller - B62D: MOTOR VEHICLES; TRAILERS (steering, or guiding on a desired track, of agricultural machines or implements A01B69/00; wheels, castors, axles, increasing wheel adhesion B60B; vehicle tyres, tyre inflation or tyre changing B60C; connections between vehicles of a train or the like B60D; vehicles for use on rail and road, amphibious or convertible vehicles B60F; suspension arrangements B60G; heating, cooling, ventilating or other air treating devices B60H; windows, windscreens, non-fixed roofs, doors or similar devices, protective coverings for vehicles not in use B60J; propulsion plant arrangements, auxiliary drives, transmissions, controls, instrumentation or dashboards B60K; electric equipment or propulsion of electrically-propelled vehicles B60L; power supply for electrically-propelled vehicles B60M; passenger accommodation not otherwise provided for B60N; adaptations for load transportation or to carry special loads or objects B60P; arrangement of signalling or lighting devices, the mounting or supporting thereof or circuits therefor, for vehicles in general B60Q; vehicles, vehicle fittings or vehicle parts not otherwise provided for B60R; servicing, cleaning, repairing, supporting, lifting, or manoeuvring, not otherwise provided for, B60S; brake arrangements, brake control systems or parts thereof B60T; air-cushion vehicles B60V; motor-cycles, accessories therefor B62J, B62K; testing of vehicles G01M) - 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) ## Abstract In one embodiment, an autonomous driving vehicle (ADV) steering control system determines how much and when to apply a steering control to maneuver obstacles of a planned route. The steering control system calculates a first steering angle based on a target directional angle and an actual directional angle of the ADV, a second steering angle based on a target lateral position and an actual lateral position of the ADV to maneuver a planned route, an object, or an obstacle course. The steering control system determines a target steering angle based on the first steering angle and the second steering angles and utilizes the target steering angle to control a subsequent steering angle of the ADV. ## Claims ### Claim 1 A computer-implemented method for steering controlling of an autonomous vehicle, the method comprising: calculating a first steering angle based on a target directional angle and an actual directional angle of the autonomous vehicle to maneuver an obstacle course; calculating a second steering angle based on a target lateral position and an actual lateral position of the autonomous vehicle to maneuver the obstacle course; determining a next target steering angle based on the first and second steering angles; and controlling a subsequent steering angle of the autonomous vehicle based on the next target steering angle. ### Claim 2 (depends on 1) The method of claim 1, wherein calculating a first steering angle comprises: determining the target directional angle of the autonomous vehicle to maneuver the obstacle course; determining the actual directional angle of the autonomous vehicle in motion; and calculating the first steering angle based on the target and actual steering angles using a first proportion-integral-derivative (PID) controller. ### Claim 3 (depends on 2) The method of claim 2, further comprising: determining a current speed of the autonomous vehicle; and adjusting a proportional coefficient of the first PID controller based on the current speed of the autonomous vehicle. ### Claim 4 (depends on 3) The method of claim 3, further comprising reducing the proportional coefficient of the first PID controller in response to determining that the current speed is above a predetermined threshold. ### Claim 5 (depends on 3) The method of claim 3, further comprising adjusting a derivative coefficient of the first PID controller based on the current speed of the autonomous vehicle. ### Claim 6 (depends on 2) The method of claim 2, further comprising: determining a turning radius of the autonomous vehicle; and adjusting a proportional coefficient of the first PID controller based on the turning radius of the autonomous vehicle. ### Claim 7 (depends on 6) The method of claim 6, further comprising increasing the proportional coefficient of the first PID controller in response to determining that the turning radius is above a predetermined threshold. ### Claim 8 (depends on 1) The method of claim 1, wherein calculating a second steering angle comprises: determining the target lateral position of the autonomous vehicle to maneuver the obstacle course; determining the actual lateral position of the autonomous vehicle in motion; and calculating the second steering angle based on the target and actual lateral positions using a second proportion-integral-derivative (PID) controller. ### Claim 9 (depends on 8) The method of claim 8, further comprising adjusting the proportional, integral and derivative coefficients of the second PID controller based on at least one of a current speed of the autonomous vehicle, a current turning radius of the autonomous vehicle for a vehicular path, and a last command of the autonomous vehicle. ### Claim 10 A non-transitory machine-readable medium having instructions stored therein, which when executed by a processor, cause the processor to perform operations of steering control of an autonomous vehicle, the operations comprising: calculating a first steering angle based on a target directional angle and an actual directional angle of the autonomous vehicle to maneuver an obstacle course; calculating a second steering angle based on a target lateral position and an actual lateral position of the autonomous vehicle to maneuver the obstacle course; determining a next target steering angle based on the first and second steering angles; and controlling a subsequent steering angle of the autonomous vehicle based on the next target steering angle. ### Claim 11 (depends on 10) The machine-readable medium of claim 10, wherein calculating a first steering angle comprises: determining the target directional angle of the autonomous vehicle to maneuver the obstacle course; determining the actual directional angle of the autonomous vehicle in motion; and calculating the first steering angle based on the target and actual steering angles using a first proportion-integral-derivative (PID) controller. ### Claim 12 (depends on 11) The machine-readable medium of claim 11, wherein the operations further comprise: determining a current speed of the autonomous vehicle; and adjusting a proportional coefficient of the first PID controller based on the current speed of the autonomous vehicle. ### Claim 13 (depends on 12) The machine-readable medium of claim 12, wherein the operations further comprise reducing the proportional coefficient of the first PID controller in response to determining that the current speed is above a predetermined threshold. ### Claim 14 (depends on 12) The machine-readable medium of claim 12, wherein the operations further comprise adjusting a derivative coefficient of the first PID controller based on the current speed of the autonomous vehicle. ### Claim 15 (depends on 11) The machine-readable medium of claim 11, wherein the operations further comprise: determining a turning radius of the autonomous vehicle; and adjusting a proportional coefficient of the first PID controller based on the turning radius of the autonomous vehicle. ### Claim 16 (depends on 15) The machine-readable medium of claim 15, wherein the operations further comprise increasing the proportional coefficient of the first PID controller in response to determining that the turning radius is above a predetermined threshold. ### Claim 17 (depends on 10) The machine-readable medium of claim 10, wherein calculating a second steering angle comprises: determining the target lateral position of the autonomous vehicle to maneuver the obstacle course; determining the actual lateral position of the autonomous vehicle in motion; and calculating the second steering angle based on the target and actual lateral positions using a second proportion-integral-derivative (PID) controller. ### Claim 18 (depends on 17) The machine-readable medium of claim 17, wherein the operations further comprise adjusting the proportional, integral and derivative coefficients of the second PID controller based on at least one of a current speed of the autonomous vehicle, a current turning radius of the autonomous vehicle for a vehicular path, and a last command of the autonomous vehicle. ### Claim 19 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 of steering control of an autonomous vehicle, the operations including calculating a first steering angle based on a target directional angle and an actual directional angle of the autonomous vehicle to maneuver an obstacle course; calculating a second steering angle based on a target lateral position and an actual lateral position of the autonomous vehicle to maneuver the obstacle course; determining a next target steering angle based on the first and second steering angles; and controlling a subsequent steering angle of the autonomous vehicle based on the next target steering angle. ### Claim 20 (depends on 19) The data processing system of claim 19, wherein calculating a first steering angle comprises: determining the target directional angle of the autonomous vehicle to maneuver the obstacle course; determining the actual directional angle of the autonomous vehicle in motion; and calculating the first steering angle based on the target and actual steering angles using a first proportion-integral-derivative (PID) controller. ### Claim 21 (depends on 20) The data processing system of claim 20, wherein the operations further comprise: determining a current speed of the autonomous vehicle; and adjusting a proportional coefficient of the first PID controller based on the current speed of the autonomous vehicle. ### Claim 22 (depends on 21) The data processing system of claim 21, wherein the operations further comprise reducing the proportional coefficient of the first PID controller in response to determining that the current speed is above a predetermined threshold. ### Claim 23 (depends on 21) The data processing system of claim 21, wherein the operations further comprise adjusting a derivative coefficient of the first PID controller based on the current speed of the autonomous vehicle. ### Claim 24 (depends on 20) The data processing system of claim 20, wherein the operations further comprise: determining a turning radius of the autonomous vehicle; and adjusting a proportional coefficient of the first PID controller based on the turning radius of the autonomous vehicle. ### Claim 25 (depends on 24) The data processing system of claim 24, wherein the operations further comprise increasing the proportional coefficient of the first PID controller in response to determining that the turning radius is above a predetermined threshold. ### Claim 26 (depends on 19) The data processing system of claim 19, wherein calculating a second steering angle comprises: determining the target lateral position of the autonomous vehicle to maneuver the obstacle course; determining the actual lateral position of the autonomous vehicle in motion; and calculating the second steering angle based on the target and actual lateral positions using a second proportion-integral-derivative (PID) controller. ### Claim 27 (depends on 26) The data processing system of claim 26, wherein the operations further comprise adjusting the proportional, integral and derivative coefficients of the second PID controller based on at least one of a current speed of the autonomous vehicle, a current turning radius of the autonomous vehicle for a vehicular path, and a last command of the autonomous vehicle.