Haptic driver feedback via steering wheel during brake steer fallback for steer-by-wire systems

Abstract

A number of illustrative variations can include systems and methods that dynamically modify steering wheel effort and travel end limits during brake-steer implementation in an electric power steering failure, steer-by-wire failure, or a vehicle where the steering system has degraded or failed to provide a normal or near normal steering driving experience to the driver while the brake-steer system is in use.

Description

[0001] Cross Reference to Related Applications

[0002] This application claims the benefit of U.S. provisional application serial number 63 / 233,834, filed August 17, 2021. TECHNICAL FIELD

[0003] The field of the disclosure generally relates to steering systems. BACKGROUND

[0004] Vehicles typically include steering systems, including electronic power steering systems that incorporate steer-by-wire technology. SUMMARY

[0005] A number of illustrative variations can include systems and methods that dynamically modify steering wheel effort and end of travel limits during brake steering implementation in a vehicle in which the steering system has failed. Brake steering systems can include providing varying brake pressures to different vehicle wheels as needed to steer the vehicle. Brake steering systems can reduce vehicle lateral performance compared to normal steering. Dynamically modifying the required effort and end of travel limits of the steering wheel based on feedback from vehicle systems and electronic brake systems can provide the required steering effort to the driver while the brake steering system is in use that conveys information about the vehicle response and capabilities.

[0006] Other illustrative variations within the scope of the present disclosure will become apparent from the detailed description provided hereinafter. It should be understood that the detailed description and specific examples, while indicating the preferred BRIEF DESCRIPTION OF DRAWINGS

[0007] Examples of variations within the scope of the present disclosure will become more fully understood from the detailed description and accompanying drawings, in which:

[0008] Figure 1 illustrative variations of systems having hardware sufficient to perform at least some of the methods described herein are depicted; and

[0009] Figure 2 illustrative variations of vehicles equipped with hardware sufficient to perform at least some of the systems and methods described herein are depicted. DETAILED DESCRIPTION

[0010] The following description of alternatives is merely illustrative in nature and is in no way intended to limit the scope of the application, its application, or uses.

[0011] In a number of illustrative alternatives, the vehicle can include a steering system. In such cases, the steering system can be manually operated by a driver via a steering interface, autonomously operated by an autonomous steering system, or operated as a combination of autonomous and manual steering, where the steering system is configured to simultaneously receive and interpret steering inputs from the driver, the autonomous steering system, or both.

[0012] In a number of illustrative alternatives, the steering interface can include a handwheel, a joystick, a trackball, a slider, a throttle, a button, a toggle switch, a lever, a touchscreen, a mouse, or any other known user input means.

[0013] In a number of illustrative alternatives, the vehicle can include a steering system that includes a steering interface and steerable propulsion systems, such as but not limited to a steering wheel and wheels, respectively. The steering system can be of the steer-by-wire type, where physical mechanisms do not mechanically communicate manipulation of the steering interface to the steerable propulsion systems, and where manipulation of the steering interface influences associated manipulation of the steerable propulsion systems via communication of electronic devices, such as but not limited to sensors, transceivers, and electronically energized actuators. According to some alternatives, the steer-by-wire system can include at least one wheel actuator and at least one handwheel actuator in operable communication with one another via an electronic power steering system or controller. The electronic power steering system can include a wheel actuator system in operable communication with a handwheel actuator system, where rotation of the steering wheel of the vehicle translates into actuation of the wheel actuator system such that the vehicle wheels can be turned.

[0014] The handwheel actuator system can include a steering wheel, a handwheel actuator, such as an electronic motor, and a handwheel angle sensor. The handwheel actuator system can be constructed and arranged to communicate handwheel angle and position to a wheel actuator system that includes at least one steering actuator that is constructed and arranged to pivot or turn a wheel.

[0015] In various illustrative variations, a vehicle can include an electronic braking system structured and arranged to apply brake pressure to any number of wheels to slow or stop the vehicle based on driver handwheel input. The electronic braking system can be in operable communication with an electronic power steering system, a handwheel actuator system, and a wheel actuator system via at least one controller. The controller can implement any number of systems, including algorithms, for monitoring and controlling propulsion, steering, and braking. According to some variations, in the event that a portion of the steer-by-wire system has failed, such as an operable disconnect between the wheel actuator system and the wheel actuators, the electronic braking system can be utilized to apply differential brake pressure to a plurality of wheels to effect lateral motion of the vehicle. In some instances, in the event that the wheel actuators have failed and the handwheel actuators are functioning correctly, a brake-steer system can be employed to apply brake pressure to individual wheels as a function of driver steering input to the handwheel. The system can communicate a request to the handwheel actuators to adjust the handwheel effort and steering travel limits to communicate to the driver that the vehicle has reduced lateral capability, or that the vehicle or the vehicle's steering system is in a degraded state.

[0016] A brake-steer driver feedback system can signal to the driver via the handwheel of the vehicle that the vehicle can be operating in a degraded mode, such as brake-steer, and that the vehicle can not be able to maneuver as effectively as the driver can be accustomed to (such as with a fully functioning steer-by-wire system).

[0017] Drivers can become accustomed to how a vehicle traditionally reacts to driver steering effort, handwheel movement, and end-of-travel limits of the handwheel in vehicles utilizing a steer-by-wire system. Drivers can expect a certain, predictable steering effort and vehicle yaw response to driver steering input. A system implementing a brake-steer system and functionality can have a delay in yaw response to handwheel driver input, and reduced lateral capability, as compared to a vehicle utilizing a steer-by-wire system.

[0018] Altering the haptic handwheel feel to mimic steer-by-wire operation can provide a predictable steering effort experience to the driver while driving if the driver is required to use a non-normal steering mechanism, such as a brake-steer system. Altering the haptic handwheel feel can also provide a means for the vehicle to effectively communicate to the driver that the vehicle is operating using a non-traditional steering system, or is operating in an erroneous or degraded state. In various illustrative variations, the haptic feedback via the handwheel of the vehicle can be manipulated by request, sent from the electronic control unit to the handwheel actuators via a steering feel emulation software module implemented by the electronic control unit.

[0019] Increasing or decreasing the torque within the steering system can occur to modify the haptic feedback in the hand wheel. The reference torque overlay can include the expected or target steering effort that a driver feels in the hand wheel under normal operating conditions. Modifying the torque overlay can include accounting for the applied hand wheel angle, hand wheel rotation speed, brake pressure request, and vehicle speed. An electronic control unit in operable communication with the hand wheel actuator can increase or decrease the torque on the hand wheel required by the driver to simulate the feel of a degraded steering system and effectively communicate the limited capabilities of the steering system haptically to the driver.

[0020] Modifying the hand wheel angle limit can also occur to modify the haptic feedback in the hand wheel. The clockwise or counterclockwise rotation of the hand wheel can be limited to modify the steering effort that a driver feels in the hand wheel during use. The modified hand wheel angle can be a function of vehicle dynamics calculations based on the reduced lateral capability when implementing a brake steering system. The modified hand wheel angle can prevent the driver from turning or rotating the hand wheel beyond the hand wheel angle in the event of a reduced differential brake lateral capability. An electronic control unit in operable communication with the hand wheel actuator can modify the hand wheel angle as a function of vehicle dynamics calculations to communicate to the driver that the vehicle is operating while using a unique lateral actuation mechanism, such as brake steering.

[0021] The system can be further constructed and arranged to provide a visual or audible signal via a human-machine interface to notify the driver that the vehicle is implementing a brake steering function and that the vehicle can be in a reduced performance mode. The visual or audible signal can include a light, noise, etc. that is easily perceived by the driver, such as where the instrument panel can include an illuminated element indicating the brake steering function or an audio tone indicating the brake steering function.

[0022] Figure 1 An illustrative variation of a system for providing haptic feedback to a driver of a vehicle in which an electronic steering system is operating in a faulted or degraded state is depicted. The system 100 can include modifying 102 a reference torque overlay of a hand wheel actuator to provide haptic feedback to the driver in the form of increased resistance when turning the hand wheel, etc. The system can include haptically communicating 104 via the hand wheel in operable communication with the hand wheel actuator that the electronic steering system is operating in a degraded state. The system 100 can also include modifying 106 a hand wheel angle limit of the hand wheel actuator such that the rotational angle of the hand wheel can be increased or decreased to haptically communicate 108 via the hand wheel that the vehicle can be operating while using an abnormal lateral movement mechanism, such as a brake steering function. The system can simulate 110 the haptic feel of a degraded electronic steering system via the hand wheel according to the modified reference torque overlay and the modified hand wheel angle limit.

[0023] Figure 2 An illustrative variation depicting portions of a vehicle implementing a system 250 for providing haptic feedback to a driver of a vehicle in which an electronic steering system, such as steer-by-wire, is operating in a faulted or degraded state. The vehicle 250 can include at least one steerable wheel 242 as part of a steer-by-wire system, an electronic brake system 216, a wheel actuator system 214 and a hand wheel actuator system 246, and at least one controller 212 in operable communication with the wheel actuator system 214, the electronic brake system 216 and the hand wheel actuator system 246. A hand wheel 244 can be in operable communication with the hand wheel actuator system 246 and can be rotated according to a hand wheel angle 272 and can include a reference torque overlay 270. In some instances, the hand wheel actuator system 246 and the wheel actuator system 214 can be operating in a degraded state, which can include a faulted or faulty communication between the hand wheel actuator 246 and the wheel actuator system 214. The steer-by-wire system, the wheel actuator system 214 or the hand wheel actuator 246 can communicate the degraded state of the wheel actuator system 214 to the controller 212 and the controller 212 can implement an abnormal lateral movement system or mechanism, such as brake steering, via the electronic brake system 216. In this case, the controller 212 can provide a command to the hand wheel actuator 246 to simulate a haptic feel of a degraded electronic steering system, such as a steer-by-wire system, by modifying the reference torque overlay 270 and modifying the hand wheel angle limit 272.

[0024] The following description of variants is merely illustrative of components, elements, acts, products and methods that are considered to be within the scope of the present invention and are not intended to limit such scope in any way except as set forth in the appended claims. The components, elements, acts, products and methods described herein can be combined and rearranged in other combinations and are still considered to be within the scope of the present invention, as explicitly recited in the claims.

[0025] According to variant 1, a method can include implementing at least one electronic control unit in operable communication with an electronic steering system including a hand wheel actuator; modifying a reference torque overlay of the hand wheel actuator based on at least one of an applied hand wheel angle, a hand wheel rotation speed, a brake pressure request or a vehicle speed; simulating a haptic feel of a degraded electronic steering system via a hand wheel; haptically communicating limited capabilities of the electronic steering system to a driver; modifying at least one hand wheel angle limit of the hand wheel actuator based on vehicle dynamic calculations of reduced lateral capabilities of the vehicle; and haptically communicating to the driver that the vehicle is operating while using a unique lateral actuation mechanism.

[0026] Variant 2 can include the method as in any of variants 1, further comprising generating a reminder by providing a visual cue via a human-machine interface, the reminder informing the driver that the vehicle is operating in a degraded mode.

[0027] Variant 2 can include the method as in any of variants 1-2, further comprising generating a reminder by providing an audio cue via a human-machine interface, the reminder informing the driver that the vehicle is operating in a degraded mode.

[0028] Variant 4 can include the method as in any of variants 1-3, wherein simulating a haptic feel of a degraded electronic steering system via a hand wheel comprises increasing a torque required to rotate the hand wheel.

[0029] Variant 5 can include the method as in any of variants 1-4, wherein simulating a haptic feel of a degraded electronic steering system via a hand wheel comprises providing haptic feedback to the driver via the hand wheel.

[0030] Variant 6 can include the method as in any of variants 1-5, simulating a haptic feel of a degraded electronic steering system via a hand wheel comprises increasing a torque required to rotate the hand wheel and decreasing the at least one hand wheel angle limit.

[0031] Variant 7 can include the method as in any of variants 1-6, wherein modifying the at least one hand wheel angle limit of the hand wheel actuator comprises decreasing the at least one hand wheel angle limit.

[0032] Variant 8 can include the method as in any of variants 1-7, wherein haptically communicating to the driver that the vehicle is operating while using a unique lateral actuation mechanism comprises increasing a torque required to rotate the hand wheel and decreasing the at least one hand wheel angle limit.

[0033] According to variant 9, a method can include implementing a vehicle comprising a plurality of vehicle systems, the plurality of vehicle systems comprising a brake system configured to manipulate a brake set, a steering system configured to adjust a wheel direction, and a controller in operable communication with the brake system and the steering system; implementing a brake steering system via the controller; modifying, via the controller, a reference torque overlay of a hand wheel actuator based on at least one of a hand wheel angle, a hand wheel rotation speed, a brake pressure request, or a vehicle speed; and modifying, via the controller, at least one hand wheel angle limit of the hand wheel actuator based on a vehicle dynamic calculation of a reduced lateral capability of the vehicle.

[0034] Variant 10 can include the method as in variant 9, further comprising generating a reminder by providing a visual cue via the human-machine interface, the reminder notifying the driver that the vehicle is operating in a degraded mode.

[0035] Variant 11 can include the method as in any of variants 9-10, further comprising generating a reminder by providing an audio cue via the human-machine interface, the reminder notifying the driver that the vehicle is operating in a degraded mode.

[0036] Variant 12 can include the method as in any of variants 9-11, further comprising simulating a haptic feel of a degraded electronic steering system via the hand wheel comprises increasing a torque required to rotate the hand wheel.

[0037] Variant 13 can include the method as in any of variants 9-12, further comprising simulating a haptic feel of a degraded electronic steering system via the hand wheel comprises providing haptic feedback to the driver via the hand wheel.

[0038] Variant 14 can include the method as in any of variants 9-13, wherein simulating a haptic feel of a degraded electronic steering system via the hand wheel comprises increasing a torque required to rotate the hand wheel and decreasing the at least one hand wheel angle limit.

[0039] Variant 15 can include the method as in any of variants 9-14, wherein modifying the at least one hand wheel angle limit of the hand wheel actuator comprises decreasing the at least one hand wheel angle limit.

[0040] Variant 16 can include the method as in any of variants 9-15, further comprising haptically communicating to the driver that the vehicle is operating while using a brake steering system comprises increasing a torque required to rotate the hand wheel and decreasing the at least one hand wheel angle limit.

[0041] According to variant 17, a method can include implementing a vehicle comprising a plurality of vehicle systems, the plurality of vehicle systems comprising a human-machine interface, a brake system configured to manipulate a brake device, a steering system configured to adjust a wheel direction via a hand wheel actuator, and a controller in operable communication with the brake system and the steering system; implementing a brake steering system via the controller; modifying a reference torque overlay of the hand wheel actuator based on at least one of a hand wheel angle applied, a hand wheel rotation speed, a brake pressure request, or a vehicle speed; simulating a haptic feel of a degraded electronic steering system via the hand wheel; communicating limited capabilities of the electronic steering system to the driver; modifying at least one hand wheel angle limit of the hand wheel actuator based on a vehicle dynamic calculation of a reduced lateral capability of the vehicle; and haptically communicating to the driver that the vehicle is operating while using a brake steering system.

[0042] Variant 18 can include the method as in any of variants 17, wherein communicating the limited capability of the electronic steering system to the driver comprises providing a visual cue via the human-machine interface.

[0043] Variant 19 can include the method as in any of variants 17-18, wherein communicating the limited capability of the electronic steering system to the driver comprises providing an audio cue via the human-machine interface.

[0044] Variant 20 can include the method as in any of variants 17-19, wherein haptically communicating to the driver that the vehicle is operating while using a brake-steer system comprises increasing a torque required to rotate the handwheel and decreasing the at least one handwheel angle limit.

[0045] The above description of selected variations of the application is merely illustrative in nature and, thus, variations or modifications of the variations or variants described herein are considered to be within the spirit and scope of the application.

Claims

1. A method for providing tactile feedback to a driver of a vehicle in which the electronic steering system is operating in a malfunctioning or degraded state, comprising: A vehicle comprising multiple vehicle systems, the multiple vehicle systems including a braking system configured to operate braking devices, a steering system configured to adjust wheel direction, and a controller operatively communicating with the braking system and the steering system; The braking and steering system is implemented via the controller; The controller modifies the reference torque superposition of the handwheel actuator based on at least one of the applied handwheel angle, handwheel rotation speed, brake pressure request, or vehicle speed. as well as The controller modifies at least one handwheel angle limit of the handwheel actuator based on vehicle dynamics calculations of the vehicle's reduced lateral capability.

2. The method of claim 1, further comprising: A reminder is generated by providing visual cues via a human-machine interface, which informs the driver that the vehicle is operating in downgraded mode.

3. The method of claim 1, further comprising: A reminder is generated by providing an audio prompt via a human-machine interface, which notifies the driver that the vehicle is operating in downgraded mode.

4. The method of claim 1, further comprising: Simulating the tactile feel of a degraded electronic steering system via the handwheel includes increasing the torque required to rotate the handwheel.

5. The method of claim 1, further comprising: Simulating the tactile feel of a degraded electronic steering system via the handwheel includes providing tactile feedback to the driver via the handwheel.

6. The method of claim 5, wherein simulating the tactile feel of a degraded electronic steering system via the handwheel comprises: Increase the torque required to rotate the handwheel and reduce the angle limit of at least one of the handwheels.

7. The method of claim 1, wherein modifying at least one handwheel angle limit of the handwheel actuator comprises: Reduce the angle limit of at least one handwheel.

8. The method of claim 1, further comprising: Tactilely communicating to the driver that the vehicle is being operated while using the braking and steering system includes increasing the torque required to rotate the handwheel and decreasing the angle limit of the at least one handwheel.

9. A method for providing tactile feedback to a driver of a vehicle in which the electronic steering system is operating in a malfunctioning or degraded state, comprising: A vehicle comprising multiple vehicle systems, the multiple vehicle systems including a human-machine interface, a braking system configured to operate braking devices, a steering system configured to adjust wheel direction via a handwheel actuator, and a controller operatively communicating with the braking system and the steering system. The braking and steering system is implemented via the controller; The reference torque superposition of the handwheel actuator is modified based on at least one of the applied handwheel angle, handwheel rotation speed, brake pressure request, or vehicle speed. The tactile feel of a degraded electronic steering system is simulated via the handwheel; Communicate the limited capabilities of the steering system to the driver; The vehicle dynamics calculation based on the reduced lateral capability of the vehicle is used to modify at least one handwheel angle limit of the handwheel actuator. as well as The vehicle is tactilely communicated to the driver as it operates while using the braking and steering systems.

10. The method of claim 9, wherein communicating the limited capabilities of the steering system to the driver comprises: Visual cues are provided through a human-machine interface.

11. The method of claim 9, wherein communicating the limited capabilities of the electronic steering system to the driver comprises: Audio prompts are provided via a human-machine interface.

12. The method of claim 9, wherein tactilely communicating to the driver that the vehicle is being operated while using the braking and steering system comprises: Increase the torque required to rotate the handwheel and reduce the angle limit of the at least one handwheel.

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