Electronic power steering system rack force observer vehicle diagnostic device

Abstract

The present invention relates to an electronic power steering system rack force observer vehicle diagnostic device. Many illustrative variations may include a method for a vehicle having an electronic steering system, a position control module, an electronic steering system rack force observer, and a rack force observer vehicle diagnostic device, wherein the method includes the following steps: providing a vehicle that may include an electronic steering system, a position control module, an electronic steering system rack force observer, and a rack force observer vehicle diagnostic device; measuring a steering angle and a steering speed of the vehicle; transmitting the steering angle of the vehicle to the position control module and the electronic steering system rack force observer; transmitting the steering speed of the vehicle to the electronic steering system rack force observer; transmitting an electronic steering system motor command to the electronic steering system rack force observer; and estimating rack force data and transmitting the rack force data to the rack force observer vehicle diagnostic device; and determining a compensated target steering angle.

Description

Technical Field

[0001] The general field to which the present disclosure relates includes vehicle steering systems. Background Art

[0002] The vehicle may include a steering system. Autonomous driving and steering systems commonly associated with "self-driving vehicles" may include an electronic steering system that can autonomously control the vehicle and maintain or change the direction in which the vehicle is traveling, primarily relying on the steering angle. Summary of the invention

[0003] A method for use in a vehicle having an electronic steering system, a position control module, an electronic steering system rack force observer, and a rack force observer vehicle diagnostic device, wherein the method may include measuring a steering angle and a steering speed of the vehicle; transmitting the steering angle of the vehicle to the position control module and the electronic steering system rack force observer; transmitting the steering speed of the vehicle to the electronic steering system rack force observer; transmitting an electronic steering system motor command to the electronic steering system rack force observer; and estimating rack force data and transmitting the rack force data to the rack force observer vehicle diagnostic device; and determining a compensated target steering angle.

[0004] A method for use in a vehicle having an electronic steering system, a position control module, an electronic steering system rack force observer, and a rack force observer vehicle diagnostic device, wherein the method may include receiving rack force data from the electronic steering system rack force observer; receiving vehicle speed data from a wheel speed sensor module, vehicle status data from an inertial measurement unit module, vehicle network data from a brake system module, and position data from a GPS module; analyzing the rack force data from the electronic steering system rack force observer, the vehicle speed data from the wheel speed sensor module, the vehicle status data from the inertial measurement unit module, the vehicle network data from the brake system module, and position data from the GPS module; approximating steering offset diagnostic data; transmitting the approximate steering offset diagnostic data to a motion control module; receiving the steering offset diagnostic data from the rack force observer vehicle diagnostic module; and approximating a compensated target steering angle.

[0005] A method may include the steps of providing an electronic power steering system, the electronic power steering system may include a steering rack, at least one wheel, a brake system module, a wheel speed sensor module, an inertial measurement unit module, a position control module, a motion control module, a GPS module, an electronic steering system rack force observer, a rack force observer vehicle diagnostic device, at least one computing device, a memory storing computer executable components, and a processor executing the computer executable components stored in the memory. The computer executable components, when executed by the processor, may perform a method, the method including receiving and analyzing rack force data from the electronic steering system rack force observer, vehicle speed data from the wheel speed sensor module, vehicle status data from the inertial measurement unit module, vehicle network data from the brake system module, and position data from the GPS module; approximating steering offset diagnostic data; transmitting the steering offset diagnostic data to the motion control module; approximating a compensated target steering angle; transmitting the compensated target steering angle to the position control module; and adjusting the steering angle of at least one wheel.

[0006] Other illustrative variations within the scope of the present invention will become apparent from the detailed description provided below. It should be understood that the detailed description and specific examples, while disclosing variations of the present invention, are intended for purposes of illustration only and are not intended to limit the scope of the present invention. BRIEF DESCRIPTION OF THE DRAWINGS

[0007] Selected examples of variations within the scope of the invention will be more fully understood from the detailed description and accompanying drawings, in which:

[0008] Figure 1 An illustrative variation of a product is depicted, the product comprising an electronic steering system equipped with hardware sufficient to perform at least some of the methods described herein;

[0009] Figure 2 A flow chart illustrating an example process of a system capable of approximating a compensated target steering angle and adjusting a vehicle steering angle; and

[0010] Figure 3 A flow chart illustrating an electronic steering system capable of approximating a compensated target steering angle and adjusting the vehicle steering angle is shown. DETAILED DESCRIPTION

[0011] The following description of the variations is merely illustrative in nature and is not intended to limit the scope of the invention, its application, or uses.

[0012] As used herein, "vehicle" may broadly refer to freight or passenger vehicles, automobiles, aerial vehicles such as drones, airplanes, and their manned and unmanned variants.

[0013] As used herein, an "operating environment" may broadly refer to a road, highway, street, path, parking lot, parking structure, tunnel, bridge, traffic intersection, residential garage, or commercial garage. It is contemplated that an operating environment may include any location or space accessible to a vehicle.

[0014] In a number of illustrative variations, the vehicle may include an electronic steering system. In such cases, the steering system may be manually operated by the driver via a steering interface, may be autonomously operated by an autonomous steering system, or may be operated as a combination of autonomous and manual steering, wherein the steering system is configured to simultaneously receive and interpret steering inputs from the driver, the autonomous steering system, or both.

[0015] In a number of illustrative variations, the steering interface may include a hand wheel, a joystick, a trackball, a slider, a throttle, a button, a toggle switch, a lever, a touch screen, a mouse, or any other known user input device.

[0016] In a number of illustrative variations, a vehicle may include a steering system including a steering interface and a steerable propulsion system, such as, but not limited to, a steering wheel, a steering rack, and road wheels. The steering system may be of an electric power steering type, in which a physical linkage mechanically transmits manipulation of the steering interface to the steerable propulsion system. The steering system may be of a steer-by-wire type, in which a physical mechanism does not mechanically transmit manipulation of the steering interface to the steerable propulsion system, and in which manipulation of the steering interface affects associated manipulation of the steerable propulsion system via communication of electronic equipment, such as, but not limited to, sensors, transceivers, and electronically actuated actuators.

[0017] In a number of illustrative variations, an electronic steering system in an autonomous vehicle can affect the trajectory of a vehicle via a motion control system that can include multiple sensors. Multiple sensors can measure and / or observe various road driving factors, such as vehicle speed, wheel speed, wheel angle, yaw rate, acceleration, roll angle, pitch angle, braking system activity, global positioning system (GPS) and data, and other measurable variables related to vehicle travel. An electronic steering system in an autonomous vehicle can measure the steering angle position to determine the trajectory. For example, an autonomous vehicle can determine that a turning vehicle must adjust the steering angle "X" degrees to complete an autonomous turn. An electronic steering system in an autonomous vehicle can measure the force on the vehicle steering rack, or an approximate force on the steering rack can be calculated by a rack force observer. The rack force observer can monitor the current inside the electronic steering system relative to the position of the electric motor to approximate the force on the steering rack. In this way, sudden changes in rack force caused by external influences originating from the operating environment can be observed, measured, and then compensated.

[0018] In a number of illustrative variations, a vehicle with an electronic steering system can measure, observe, collect or approximate the force on the vehicle steering rack in addition to factors such as vehicle speed, wheel speed, wheel angle, yaw rate, acceleration, roll angle, pitch angle, brake system activity, global positioning system (GPS) and data, and other factors. A motion control system combined with modules such as a position controller, a steering rack force observer, a motion controller, a motion position sensor, a brake system sensor, an inertial measurement unit (IMU), GPS, and various other systems can measure or approximate disturbances from the vehicle operating environment that may affect wheel angles and rack forces. For example, a motion control system measures wheel angles approximately parallel to the vehicle trajectory, but also measures or approximates rack forces that are greater than expected, and dynamic conditions such as adverse driving conditions, component failures within the electronic steering system, or other conditions can be determined. Disturbances in the steering rack force can be determined by monitoring the steering angle position and the steering angle offset relative to the straight position, and can be confirmed by secondary vehicle sensors such as wheel speed sensors, vehicle heading, yaw rate, and lateral acceleration sensors.

[0019] The measured steering rack force, along with the measured steering position, can provide a wealth of information to the vehicle that might not otherwise be measured or observed. The system can aid in situation identification and diagnosis when vehicle maintenance is required. Dynamic situations can be identified, such as braking on split-mu surfaces, torque steer at on-throttle, wheel lifting at high lateral acceleration, tire blowouts, and up / down camber and crowned roads. Suspension and tire diagnostics can also be identified, such as bad ball joints, tie rod ends, shocks, brake disc issues, tire imbalance, and tire inflation. The cause of the disturbance can be identified from information from steering angle position (including compensation), rack load force, and with the aid of other vehicle sensors such as wheel speed sensors and lateral acceleration. The situation identification can then be transmitted to and used by systems throughout the vehicle, including signaling maintenance as needed, adjusting autonomous driving trajectory or speed, or indicating to the driver that trajectory or speed adjustments may be required when motion control systems are unable to do so.

[0020] refer to Figure 1 , an illustrative variation of the product may include an electronic power steering system 10, which includes an electronic road wheel actuator 12 and a motion control system 14. The motion control system 14 and / or the electronic power steering system may include: at least one computing device; a memory storing computer executable components; a processor executing the computer executable components stored in the memory. The electronic road wheel actuator 12 may include a position control module 16, a motion position sensor 18, and an electronic steering rack force observer 20. The motion control system 14 may include a rack force observer vehicle diagnostic device 22 and a motion controller 24.

[0021] The motion position sensor 18 can transmit the steering angle of the vehicle to the position control module 16 and the electronic steering system rack force observer 20. The motion position sensor 18 can transmit the steering speed to the electronic steering system rack force observer 20. The position control module 16 can transmit the electronic steering system motor command to the electronic steering system rack force observer 20. The position control module 16 can include a position control, torque control or torque superposition architecture. The electronic steering system rack force observer 20 can measure or estimate the rack force data and transmit the rack force to the rack force observer vehicle diagnostic device 22 within the motion control system 14.

[0022] Within the motion control system 14, the rack force observer vehicle diagnostic device 22 may receive rack force data from the electronic steering system rack force observer 20, vehicle speed data from the wheel speed sensor module 26, vehicle status data from the inertial measurement unit module 28, vehicle network data from the brake system module 30, and position data from the GPS module 32. The rack force observer vehicle diagnostic device 22 may analyze the rack force data from the electronic steering system rack force observer 20, the vehicle speed data from the wheel speed sensor module 26, the vehicle status data from the inertial measurement unit module 28, the vehicle network data from the brake system module 30, and the position data from the GPS module 32 to calculate or approximate steering offset diagnostic data, which may then be transmitted to the motion control module 24. The motion control module 24 may receive steering offset diagnostic data from the rack force observer vehicle diagnostic module 22 and may also receive position data from the GPS module 32 to calculate or approximate a compensated target steering angle 34 which may be transmitted to the position control module 16 within the electronic steering system road wheel actuator 12 .

[0023] The compensated target steering angle data 34 received by the position control module 16 may be used to adjust the steering angle, vehicle speed, or other variables to increase the safety of the autonomous driving system, signal maintenance as needed, adjust the autonomous driving trajectory or speed, or indicate to the driver that trajectory or speed may need to be adjusted when the motion control system is unable to do so.

[0024] Figure 2 is a flow chart showing an example process of a motion control system including an electronic steering system capable of approximating a compensated target steering angle and adjusting a vehicle steering angle. The motion control system and / or the electronic power steering system may include: at least one computing device; a memory storing computer executable components; a processor executing computer executable components stored in the memory, wherein the computer executable components may include steps. Step 40 may include measuring a steering angle of the vehicle and transmitting the steering angle to a position control module and an electronic steering system rack force observer. Step 42 may include measuring a steering speed and transmitting it to an electronic steering system rack force observer. Step 44 may include transmitting an electronic steering system motor command to an electronic steering system rack force observer. Step 46 may include estimating rack force data and transmitting the rack force data to a rack force observer vehicle diagnostic device. Step 48 may include adjusting a steering angle, vehicle speed, or other variable to increase the safety of an autonomous vehicle. Step 48 may also include signaling a user that maintenance of the vehicle may be required, adjusting an autonomous driving trajectory or speed, or indicating to the driver that a trajectory or speed adjustment may be required.

[0025] Figure 3 is a flow chart illustrating an example process of a motion control system including an electronic steering system capable of approximating a compensated target steering angle and adjusting a vehicle steering angle. The motion control system and / or the electronic power steering system may include: at least one computing device; a memory storing computer executable components; a processor executing computer executable components stored in the memory, wherein the computer executable components may include steps. Step 50 may include receiving rack force data from an electronic steering system rack force observer. Step 50 may also include receiving vehicle speed data from a wheel speed sensor module, vehicle status data from an inertial measurement unit module, vehicle network data from a braking system module, and position data from a GPS module. Step 52 may include analyzing rack force data from an electronic steering system rack force observer, vehicle speed data from a wheel speed sensor module, vehicle status data from an inertial measurement unit module, vehicle network data from a braking system module, and position data from a GPS module. Step 54 may include approximating steering offset diagnostic data based on data received during steps 50 and 52. Step 56 may include transmitting the approximated steering offset diagnostic data to the motion control module. Step 58 may include receiving steering offset diagnostic data from a rack force observer vehicle diagnostic module. Step 60 may optionally include receiving position data from a GPS module and transmitting the position data to a motion control module. Step 62 may include approximating a compensated target steering angle, vehicle speed, or other variable. Step 64 may include transmitting the compensated target steering angle to a position control module within the electronic steering system. Step 66 may include adjusting the steering angle, vehicle speed, or other variable to increase the safety of an autonomous vehicle including an electronic steering system. Step 66 may further include signaling maintenance as needed, adjusting the autonomous driving trajectory or speed, or indicating to a user that an adjustment to the trajectory or speed may be required.

[0026] The following description of the variations is only an explanation of the components, elements, actions, products and methods considered within the scope of the invention, and is not intended in any way to limit such scope by specifically disclosed or unexplanatory content. The components, elements, actions, products and methods described herein may be combined and rearranged, and are different from those clearly described herein, and are still considered within the scope of the invention.

[0027] According to variant 1, a method for use in a vehicle having an electronic steering system, a position control module, an electronic steering system rack force observer and a rack force observer vehicle diagnostic device, wherein the method may include measuring a steering angle and a steering speed of the vehicle; transmitting the steering angle of the vehicle to the position control module and the electronic steering system rack force observer; transmitting the steering speed of the vehicle to the electronic steering system rack force observer; transmitting an electronic steering system motor command to the electronic steering system rack force observer; and estimating rack force data and transmitting the rack force data to the rack force observer vehicle diagnostic device; and determining a compensated target steering angle.

[0028] Variation 2 may include the method as described in Variation 1 and may further include adjusting a steering angle of the vehicle.

[0029] Variation 3 may include a method as set forth in any of Variations 1-2 and may further include signaling to a user that maintenance of the vehicle is required.

[0030] Variation 4 may include a method as set forth in any of Variations 1-3 and may further include signaling to a user that an adjustment in driving trajectory or speed is required.

[0031] Variant 5 may include a method for use in a vehicle having an electronic steering system, a position control module, an electronic steering system rack force observer, and a rack force observer vehicle diagnostic device, wherein the method may include: receiving rack force data from the electronic steering system rack force observer; receiving vehicle speed data from a wheel speed sensor module, vehicle status data from an inertial measurement unit module, vehicle network data from a braking system module, and position data from a GPS module; analyzing the rack force data from the electronic steering system rack force observer, the vehicle speed data from the wheel speed sensor module, the vehicle status data from the inertial measurement unit module, the vehicle network data from the braking system module, and position data from the GPS module; approximating steering offset diagnostic data; transmitting the approximate steering offset diagnostic data to a motion control module; receiving steering offset diagnostic data from the rack force observer vehicle diagnostic module; and approximating a compensated target steering angle.

[0032] Variation 6 may include a method as set forth in Variation 5 and may further include receiving position data from a GPS module and transmitting the position data to a motion control module prior to approaching a compensated target steering angle, vehicle speed, or other variable.

[0033] Variation 7 may include a method as set forth in any of Variations 5-6 and may further include transmitting the compensated target steering angle to a position control module.

[0034] Variation 8 may include a method as set forth in any of Variations 5-7 and may further include adjusting a steering angle of the vehicle.

[0035] Variation 9 may include a method as set forth in any of Variations 5-8 and may further include signaling to a user that maintenance of the vehicle is required.

[0036] Variation 10 may include a method as set forth in any of Variations 5-9 and may further include signaling to a user that an adjustment in driving trajectory or speed is required.

[0037] Variant 11 may include an electronic power steering system, which may include a steering rack; at least one wheel; a brake system module; a wheel speed sensor module; an inertial measurement unit module; a position control module; a motion control module; a GPS module; an electronic steering system rack force observer: a rack force observer vehicle diagnostic device; at least one computing device; a memory storing computer executable components; a processor executing the computer executable components stored in the memory. The computer executable components, when executed by the processor, may result in the following actions: receiving and analyzing rack force data from the electronic steering system rack force observer, vehicle speed data from the wheel speed sensor module, vehicle status data from the inertial measurement unit module, vehicle network data from the brake system module, and position data from the GPS module; approximating steering offset diagnostic data; transmitting the steering offset diagnostic data to the motion control module; approximating a compensated target steering angle; transmitting the compensated target steering angle to the position control module; and adjusting the steering angle of at least one wheel.

[0038] The foregoing description of selected variations within the scope of the present invention is merely illustrative in nature, and thus, variations or modifications thereof should not be regarded as a departure from the spirit and scope of the present invention.

Claims

1. A method for use in a vehicle having an electronic steering system, a position control module, an electronic steering system rack force observer, and a rack force observer vehicle diagnostic device, wherein the method comprises: measuring a steering angle and a steering speed of the vehicle; transmitting the steering angle of the vehicle to the position control module and the electronic steering system rack force observer; transmitting the steering speed of the vehicle to the electronic steering system rack force observer; transmitting an electronic steering system motor command to the electronic steering system rack force observer; monitoring current within the electronic steering system relative to the position of the electric motor to calculate rack force data on the steering rack, determining whether the calculated rack force is unexpected based on the measured steering angle, and transmitting the rack force data to the rack force observer vehicle diagnostic device; and A compensated target steering angle is determined based on the rack force data relative to a straight-on steering position of the steering angle to account for sudden changes in rack force, and the steering angle of the vehicle is adjusted based on the determined compensated target steering angle if the calculated rack force is unexpected based on the measured steering angle.

2. The method according to claim 1, further comprising: The steering angle of the vehicle is adjusted.

3. The method according to claim 1, further comprising: A user is signaled that maintenance of the vehicle is required.

4. The method according to claim 1, further comprising: Signals to the user that an adjustment in driving trajectory or speed is needed.

5. A method for use in a vehicle having an electronic steering system, a position control module, an electronic steering system rack force observer, and a rack force observer vehicle diagnostic module, wherein the method comprises: The electronic steering system rack force observer is used to perform the following actions: monitoring the current within the electronic steering system relative to the position of the electric motor, calculating rack force data on the steering rack using the monitored current, and determining whether the calculated rack force is unexpected; receiving rack force data from an electronic steering system rack force observer; receiving vehicle speed data from a wheel speed sensor module, vehicle status data from an inertial measurement unit module, vehicle network data from a brake system module, and location data from a GPS module; analyzing rack force data from the electronic steering system rack force observer, vehicle speed data from the wheel speed sensor module, vehicle status data from the inertial measurement unit module, vehicle network data from the brake system module, and position data from the GPS module, calculating steering deviation diagnostic data by measuring at least one of a steering angle or a steering speed of the vehicle relative to at least one straight position; transmitting the calculated steering offset diagnostic data to a motion control module; receiving the steering offset diagnostic data from the rack force observer vehicle diagnostic module; and A compensated target steering angle is calculated based on the rack force data relative to the steering angle or the steering speed to account for sudden changes in rack force, and the steering angle of the vehicle is adjusted based on the determined compensated target steering angle when the calculated rack force is unexpected based on the measured steering angle.

6. The method according to claim 5, further comprising: Before calculating the compensated target steering angle, the position data is transmitted to the motion control module.

7. The method according to claim 6, further comprising: The calculated compensated target steering angle is transmitted to the position control module.

8. The method according to claim 7, further comprising: The steering angle of the vehicle is adjusted.

9. The method according to claim 5, further comprising: A user is signaled that maintenance of the vehicle is required.

10. The method according to claim 5, further comprising: Signals to the user that an adjustment in driving trajectory or speed is needed.

11. An electronic power steering system, comprising: Steering rack; at least one wheel; Braking system module; Wheel speed sensor module; Inertial measurement unit module; Position control module; Motion control module; GPS module; Electronic Steering System Rack Force Observer: Rack force observer vehicle diagnostic module; at least one computing device; a memory storing computer executable components; a processor that executes the computer executable components stored in the memory, wherein when executed by the processor, the computer executable components cause the following actions: receiving and analyzing rack force data from the electronic steering system rack force observer, vehicle speed data from the wheel speed sensor module, vehicle status data from the inertial measurement unit module, vehicle network data from the brake system module, and position data from the GPS module; The electronic steering system rack force observer is used to perform the following actions: monitoring the current within the electronic steering system relative to the position of the electric motor, calculating rack force data on the steering rack using the monitored current, and determining whether the calculated rack force is unexpected; calculating steering offset diagnostic data by measuring at least one of a steering angle or a steering speed of the vehicle relative to at least one of a straight position, vehicle speed data from the wheel speed sensor module, vehicle status data from the inertial measurement unit module, vehicle network data from the brake system module, or position data from a GPS module; transmitting the steering offset diagnostic data to the motion control module; calculating a compensated target steering angle based on rack force data relative to the straight position of the steering angle or the steering speed to account for sudden changes in rack force; transmitting the calculated compensated target steering angle to the position control module; and The steering angle of the at least one wheel is adjusted when the rack force data is unexpected based on the measured steering angle.

12. The electronic power steering system according to claim 11, wherein the actions further include: Before calculating the compensated target steering angle, the position data is transmitted to the motion control module.

13. The electronic power steering system according to claim 11, wherein the actions further include: A user is signaled that maintenance of the vehicle is required.

14. The electronic power steering system of claim 11, wherein the actions further comprise: Signals to the user that an adjustment in driving trajectory or speed is needed.

15. An electronic power steering system comprising: Steering rack; at least one wheel; Braking system module; Wheel speed sensor module; Inertial measurement unit module; Position control module; Motion control module; GPS module; Electronic Steering System Rack Force Observer: Rack force observer vehicle diagnostic module; at least one computing device; a memory storing computer executable components; a processor that executes the computer executable components stored in the memory, wherein when executed by the processor, the computer executable components cause the following actions: receiving and analyzing rack force data from the electronic steering system rack force observer, vehicle speed data from the wheel speed sensor module, vehicle status data from the inertial measurement unit module, vehicle network data from the brake system module, and position data from the GPS module; The electronic steering system rack force observer is used to perform the following actions: monitoring the current within the electronic steering system relative to the position of the electric motor, calculating rack force data on the steering rack using the monitored current, and determining whether the calculated rack force is unexpected; calculating steering offset diagnostic data by measuring at least one of a steering angle or a steering speed of the vehicle relative to at least one of a straight position, vehicle speed data from the wheel speed sensor module, vehicle status data from the inertial measurement unit module, vehicle network data from the brake system module, or position data from a GPS module; transmitting the steering offset diagnostic data to the motion control module; receiving the steering offset diagnostic data from the rack force observer vehicle diagnostic module; calculating a compensated target steering angle based on rack force data relative to the straight position of the steering angle or the steering speed to account for sudden changes in rack force; transmitting the calculated compensated target steering angle to the position control module; and The steering angle of the at least one wheel is adjusted when the rack force data is unexpected based on the measured steering angle.

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