SHAPE OF THE STEERING WALL HYSTERESIS FOR STEER-BY-WIRE AND CLOSED-LIVE ELECTRIC POWER STEERING

Abstract

A method for performing hysteresis shaping in a vehicle's steer-by-wire (SbW) steering system comprises determining, based on the desired hysteresis, whether to perform hysteresis subtraction or hysteresis addition, calculating a hysteresis subtraction value in response to a determination to perform hysteresis subtraction, modifying an estimated rack load based on the hysteresis subtraction value, generating a reference torque based on the estimated rack load as modified based on the hysteresis subtraction value in response to a determination to perform hysteresis addition, calculating a hysteresis addition value and generating the reference torque based on the hysteresis addition value, and controlling the handwheel based on the reference torque.

Description

CROSS-REFERENCE TO RELATED APPLICATIONS

[0001] This application claims the benefit of U.S. Provisional Application No. 63 / 534,392, filed August 24, 2023. The entire disclosure of the above-referenced applications is incorporated herein by reference. TECHNICAL FIELD

[0002] This disclosure relates to the control of components in electronic power steering (EPS) and steer-by-wire (SbW) systems. BACKGROUND OF THE INVENTION

[0003] A vehicle, such as a car, truck, sport utility vehicle, crossover, minivan, watercraft, aircraft, off-road vehicle, recreational vehicle, or other suitable means of transportation, typically includes a steering system, such as an electronic power steering (EPS) system, a steer-by-wire (SbW) system, a hydraulic steering system, or other suitable steering system. The steering system of such a vehicle typically controls various aspects of the vehicle's steering, including providing steering assistance to the vehicle's driver, controlling steerable wheels of the vehicle, and the like. SUMMARY

[0004] This disclosure relates generally to the control of steer-by-wire (SbW) steering systems.

[0005] One aspect of the disclosed embodiments includes a method for performing hysteresis shaping in a steer-by-wire (SbW) steering system of a vehicle.The method includes determining a desired hysteresis associated with rotation of a handwheel of the vehicle, determining, based on the desired hysteresis, whether to perform hysteresis subtraction or hysteresis addition, calculating a hysteresis subtraction value in response to a determination to perform hysteresis subtraction, modifying an estimated rack load based on the hysteresis subtraction value, and generating a reference torque based on the estimated rack load as modified based on the hysteresis subtraction value in response to a determination to perform hysteresis addition, calculating a hysteresis addition value and generating the reference torque based on the hysteresis addition value, and controlling the handwheel based on the reference torque.

[0006] Further areas of applicability of the present disclosure will become apparent from the detailed description, claims, and drawings. The detailed description and specific examples are for illustrative purposes only and are not intended to limit the scope of the disclosure. BRIEF DESCRIPTION OF THE DRAWINGS

[0007] The disclosure is best understood from the following detailed description when read in conjunction with the accompanying drawings. It is emphasized that, in accordance with common practice, the various features of the drawings are not drawn to scale. On the contrary, the dimensions of the various features are arbitrarily expanded or reduced for clarity. Fig. 1A generally illustrates a vehicle according to the principles of the present disclosure. Fig. 1B generally illustrates a controller according to the principles of the present disclosure. Fig. 2A generally illustrates an example of a rack and pinion or RWA controller and a column or handwheel actuator (HWA) controller of a steering system configured to implement hysteresis shaping techniques according to the principles of the present disclosure. Fig. 2B illustrates an example of a reference torque calculator configured to implement hysteresis shaping techniques according to the principles of the present disclosure. Fig. 3 is a flowchart generally illustrating a method for performing hysteresis shaping according to the principles of the present disclosure. DETAILED DESCRIPTION

[0008] The following discussion relates to various embodiments of the disclosure. Although one or more of these embodiments may be preferred, the disclosed embodiments should not be interpreted or otherwise used as limiting the scope of the disclosure, including the claims. Furthermore, one skilled in the art will understand that the following description has broad application, and the discussion of one embodiment is intended only as an example of that embodiment and does not imply that the scope of the disclosure, including the claims, is limited to that embodiment.

[0009] As described, a vehicle, such as a passenger car, truck, sport utility vehicle, crossover, minivan, watercraft, aircraft, off-road vehicle, recreational vehicle, or other suitable means of transportation, typically includes a steering system, such as an electronic power steering (EPS) system, a steer-by-wire (SbW) steering system, a hydraulic steering system, or other suitable steering system. The steering system of such a vehicle typically controls various aspects of the vehicle's steering, including providing steering assistance to the driver of the vehicle, controlling steerable wheels of the vehicle, and the like.

[0010] Steering systems require steering effort hysteresis to provide the driver with a "natural" driving feel. Too little hysteresis and the system feels springy; too much hysteresis and the system feels frictional. In linked steering systems (hydraulic power steering (HPS), electronic power steering (EPS), etc.), the hysteresis of the overall system is generally higher than desired due to friction between all involved components (both chassis components and steering system components). In SbW applications, where effort depends on the measured steering system rack force, the hysteresis is determined by the friction component of the estimated rack force. This hysteresis could be greater or less than the desired hysteresis.

[0011] Therefore, a method for increasing or decreasing effort hysteresis is needed for closed-loop SbW and EPS applications. Hysteresis shaping systems and methods according to the present disclosure implement techniques for applying hysteresis addition or addition (increase) and hysteresis compensation or subtraction (decrease) to closed-loop SbW and EPS systems.

[0012] Fig. 1A generally illustrates a vehicle 10 in accordance with the principles of the present disclosure. The vehicle 10 may include any suitable vehicle, such as a car, a truck, a sport utility vehicle, a minivan, a crossover, any other passenger vehicle, any suitable commercial vehicle, or any other suitable vehicle. While the vehicle 10 is illustrated as a wheeled passenger vehicle for use on roads, the principles of the present disclosure may also be applied to other vehicles, such as aircraft, boats, trains, drones, or other suitable vehicles.

[0013] The vehicle 10 includes a vehicle body 12 and a hood 14. A passenger compartment 18 is at least partially defined by the vehicle body 12. Another portion of the vehicle body 12 defines an engine compartment 20. The hood 14 may be movably attached to a portion of the vehicle body 12 such that the hood 14 provides access to the engine compartment 20 when the hood 14 is in a first, or open, position and the hood 14 covers the engine compartment 20 when the hood 14 is in a second, or closed, position. In some embodiments, the engine compartment 20 may be located in the rear portion of the vehicle 10, other than as generally illustrated.

[0014] The passenger compartment 18 may be located behind the engine compartment 20, but may also be located forward of the engine compartment 20 in embodiments where the engine compartment 20 is located in the rear portion of the vehicle 10. The vehicle 10 may include any suitable propulsion system including an internal combustion engine, one or more electric motors (e.g., an electric vehicle), one or more fuel cells, a hybrid propulsion system (e.g., a hybrid vehicle) comprising a combination of an internal combustion engine, one or more electric motors, and / or another suitable propulsion system.

[0015] In some embodiments, the vehicle 10 may include a gasoline or petrol engine, such as a spark-ignition engine. In some embodiments, the vehicle 10 may include a diesel engine, such as a compression-ignition engine. The engine compartment 20 houses and / or encloses at least some components of the propulsion system of the vehicle 10. Additionally or alternatively, propulsion controls such as a gas actuator (e.g., an accelerator pedal), a brake actuator (e.g., a brake pedal), a handwheel, and other such components are disposed within the passenger compartment 18 of the vehicle 10. The propulsion controls may be actuated or controlled by an operator of the vehicle 10 and may be directly connected to corresponding components of the propulsion system, such as a throttle, a brake, a vehicle axle, a vehicle transmission, and the like.In some embodiments, the drive controls may transmit signals to a vehicle computer (e.g., drive-by-wire), which in turn may control the corresponding component of the drive system. For example, in some embodiments, vehicle 10 may be an autonomous vehicle.

[0016] In some embodiments, the vehicle 10 includes a transmission connected to a crankshaft via a flywheel, a clutch, or a fluid coupling. In some embodiments, the transmission includes a manual transmission. In some embodiments, the transmission includes an automatic transmission. The vehicle 10, in the case of an internal combustion engine or a hybrid vehicle, may include one or more pistons that cooperate with the crankshaft to generate power that is transmitted through the transmission to one or more axles that rotate the wheels 22. If the vehicle 10 includes one or more electric motors, a vehicle battery and / or a fuel cell provides power to the electric motors to rotate the wheels 22.

[0017] Vehicle 10 may include automatic vehicle propulsion systems, such as cruise control, adaptive cruise control, automatic braking control, other automatic vehicle propulsion systems, or a combination thereof. Vehicle 10 may be an autonomous or semi-autonomous vehicle or another suitable vehicle type. Vehicle 10 may include additional or fewer features than those generally illustrated and / or disclosed herein.

[0018] In some embodiments, the vehicle 10 may include an Ethernet component 24, a Controller Area Network (CAN) bus 26, a Media-Oriented System Transport Component (MOST) 28, a FlexRay component 30 (e.g., a brake-by-wire system, etc.), and a Local Interconnect Network Component (LIN) 32. The vehicle 10 may use the CAN bus 26, the MOST 28, the FlexRay component 30, the LIN 32, other suitable networks or communication systems, or a combination thereof, to communicate various information from, for example, sensors inside or outside the vehicle to, for example, various processors or controllers inside or outside the vehicle. The vehicle 10 may include additional or fewer features than those generally illustrated and / or disclosed herein.

[0019] In some embodiments, the vehicle 10 may include a steering system, such as an EPS system, a steering-by-wire steering system (which may, for example, include or communicate with one or more controllers that control components of the steering system without the use of a mechanical connection between the handwheel and the wheels 22 of the vehicle 10), a hydraulic steering system (which may, for example, include a magnetic actuator incorporated into a valve assembly of the hydraulic steering system), or other suitable steering system.

[0020] The steering system may include a control system or mechanism, a closed-loop control system or mechanism, or a combination thereof. The steering system may be configured to receive various inputs, including, but not limited to, a handwheel position, an input torque, one or more road wheel positions, other suitable inputs or information, or a combination thereof.

[0021] Additionally or alternatively, the inputs may include a handwheel torque, a handwheel angle, a motor speed, a vehicle speed, an estimated motor torque command, another suitable input, or a combination thereof. The steering system may be configured to provide a steering function and / or control of the vehicle 10. For example, the steering system may generate assist torque based on the various inputs. The steering system may be configured to selectively control a motor of the steering system using the assist torque to provide steering assistance to the driver of the vehicle 10. The steering system of the present disclosure is configured to implement hysteresis shaping, described in more detail below.

[0022] In some embodiments, the vehicle 10 includes one or more controllers, such as the controller 100, as generally shown in Fig. 1B. The controller 100 may correspond to a steering system controller. The controller 100 may include any suitable controller, such as an electronic control unit or other suitable controller. The controller 100 may be configured to control, for example, the various functions of the steering system and / or various functions of the vehicle 10. The controller 100 may include a processor 102 and a memory 104. The processor 102 may include any suitable processor, such as those described herein. Additionally or alternatively, the controller 100 may include any number of processors, in addition to or different from the processor 102. The memory 104 may comprise a single disk or a plurality of disks (e.g., hard drives) and includes a memory management module that manages one or more partitions within the memory 104.In some embodiments, memory 104 may include flash memory, solid-state memory, or the like. Memory 104 may include random access memory (RAM), read-only memory (ROM), or a combination thereof. Memory 104 may include instructions that, when executed by processor 102, cause processor 102 to control at least various aspects of vehicle 10. Additionally or alternatively, memory 104 may include instructions that, when executed by processor 102, cause processor 102 to perform functions associated with the systems and methods described herein.

[0023] The controller 100 may receive one or more signals from various measuring devices or sensors 106 indicative of sensed or measured characteristics of the vehicle 10. The sensors 106 may include any suitable sensors, measuring devices, and / or other suitable mechanisms. The sensors 106 may include, for example, one or more torque sensors or devices, one or more handwheel position sensors or devices, one or more motor position sensors or devices, one or more position sensors or devices, other suitable sensors or devices, or a combination thereof. The one or more signals may indicate a handwheel torque, a handwheel angle, a motor speed, a vehicle speed, other suitable information, or a combination thereof.

[0024] As used herein, the term "controller" may refer to a hardware module or assembly that includes one or more processors or microcontrollers, memory, sensors, one or more actuators, a communications interface, etc., all portions of which may be collectively referred to as "circuitry." As described herein, the particular functions and steps performed by a particular controller, control circuit, etc., may be performed jointly by multiple controllers, processors, etc. For example, a processor, processing device, controller, control circuit, etc. that is "configured to perform" may refer to a single processor, processing device, controller, etc.configured to perform both A and B, or it may refer to a first processor, processing device, controller, etc., configured to perform A, and a second processor, processing device, controller, etc., configured to perform B. For simplicity, "control circuitry configured to perform A and B" may refer to a single or multiple processors, processing devices, controllers, etc., collectively configured to perform A and B.

[0025] In some embodiments, controller 100 may perform the methods described herein. However, the methods described herein as performed by controller 100 are not intended to be limiting, and any type of software executing on a controller, processor, or other circuitry may implement the hysteresis shaping techniques described herein without departing from the scope of this disclosure. For example, a controller, such as a processor, executing software within a computing device may implement the systems and methods described herein.

[0026] Hysteresis shaping systems and methods according to the present disclosure are configured to apply hysteresis addition or addition (increase) and hysteresis compensation or subtraction (decrease) to SbW and controlled EPS systems, such as EPS systems implemented by the vehicle 10 and those described above in Fig. 1A and Fig. 1B described controller 100 can be implemented.

[0027] Fig. 2A illustrates an example of a rack and pinion or RWA controller 200 and a column or handwheel actuator (HWA) controller 204 of a steering system configured to implement the hysteresis shaping techniques of the present disclosure. For example, the HWA controller 204 is configured to generate a motor torque command for the handwheel actuator (HWA) based on an estimated rack force (e.g., an estimated rack force signal) received from the RWA controller 200 and one or more other input signals (e.g., vehicle speed, handwheel position, and handwheel speed). The RWA controller 200 is configured to determine the estimated rack force based on the motor torque required to achieve or maintain a current rack position.The controllers 200 and 204 may correspond to, be implemented by, or be implemented by one or more controllers for the steering system.

[0028] As an example, the HWA controller 204 includes a reference torque calculator 208 configured to generate a reference torque (T ref ) is calculated based on the estimated rack force and the one or more other input signals. For example, the reference torque corresponds to a sum of various inputs / measurements such as effort, hysteresis, return correction, damping, detent, etc. A torque controller 212 (e.g., PID controller) is configured to generate and output the motor torque command based at least in part on a driver-applied force or torque (e.g., "Tbar torque") and the reference torque. The motor torque command is provided as a control signal to control a motor of the handwheel actuator.

[0029] The estimated rack force corresponds to the measured or estimated torque of the road wheel actuator. Accordingly, the estimated rack force (and any estimated offset or error in the rack force) is a critical factor in determining the force provided by the handwheel actuator motor.

[0030] In some examples, the HWA controller 204 may further include a C-factor lookup module 216 and a rack reference calculator 220. For example, the rack reference calculator 220 is configured to generate the rack reference based on a C-factor received from the C-factor lookup module 216. The C-factor may be determined based on a handwheel angle ("HwAg") corresponding to the operator input (e.g., a handwheel angle indicative of the operator's intent conveyed via the handwheel). Example systems and methods for obtaining the rack position reference and the C-factor are described in more detail in U.S. Pat. No. 18 / 318,657, filed May 16, 2023, the entire contents of which are incorporated herein by reference.

[0031] The RWA controller 200 includes a rack position controller 224 (e.g., a PID rack position controller) configured to generate one or more rack position control signals based on the actual rack position and the rack position reference (e.g., based on a difference between the actual rack position and the rack position reference). The rack position control signals may include, but are not limited to, signals for the rack motor speed and the motor torque command (e.g., for the torque applied by the driver). In this manner, the rack position is controlled to follow the driver's intent (as indicated by the rack position reference).

[0032] A rack force predictor 228 generates the estimated rack force based on outputs of the rack position controller 224 (e.g., based on a function of the rack motor speed, the rack motor torque command, etc.). In various examples, the estimated rack force may be calculated based on the torque applied by the driver to the handwheel (as indicated by the rack motor torque command, various sensor signals, etc.). As shown, the rack force predictor 228 may output the estimated rack force, and the reference torque calculator 208 (and / or another component of the RWA controller 200, the HWA controller 204, etc.) may obtain an estimated rack load based on the estimated rack force. In other examples, the rack force predictor 228 may output the estimated rack load.In some contexts, the terms “estimated rack force” and “estimated rack load” may be used interchangeably.

[0033] For example, in RWA position control, the rack position reference signal ("RackPosRef") can be calculated based on a position error ("PosErr") between an ADAS rack position reference value or signal ("ADASRackPosRef") and a HWA rack position reference value or signal ("HWARackPosRef"). Conversely, HWA position control is based on a position error between the HWA position and the RWA position, allowing the handwheel to be controlled to rotate in a manner consistent with the wheel's rotation in freehand mode.

[0034] The reference torque can correspond to a desired, ideal, or target torque felt by the driver (e.g., at the handwheel / steering wheel). As described above, the calculation of the reference torque is based on, among other factors, driver inputs (e.g., an input torque corresponding to the steering wheel angle), road conditions, damping, hysteresis, etc. A torque at the handwheel is controlled (e.g., via the HWA) to match the reference torque. For example, outputs from one or more sensors measuring the actual torque at the wheel are used to minimize the difference between the reference torque and the actual torque.

[0035] In steering systems, hysteresis corresponds to the vertical distance between the clockwise and counterclockwise directions in a graph of handwheel torque versus handwheel angle (or handwheel torque versus rack force). For example, you could collect measured data on handwheel torque and handwheel angle in a vehicle and create a plot of handwheel torque versus handwheel angle. The vertical distance between the clockwise and counterclockwise directions would be the amount of hysteresis felt by the driver. Generally, there is an ideal amount of hysteresis that provides good steering feel to the driver. Using the techniques described herein, hysteresis can be adjusted to provide the driver with this ideal profile in vehicles that use closed-loop systems for handwheel torque control.

[0036] An effort function (e.g., an effort function implemented by reference torque calculator 208) defines a relationship between the driver's input (e.g., the force or torque the driver applies to the handwheel, which may be referred to as "effort") and a response (i.e., movement) of the steering system. For example, the effort function may output an effort value based on a lookup table or other function (e.g., using an estimated rack load as input). The estimated rack load may be modified prior to input to the lookup table by adding a calculated return load value to the estimated rack load.

[0037] The effort function indicates how much effort the driver must exert to elicit a desired response. Accordingly, steering systems require hysteresis in the steering effort profile to provide the driver with a "natural" feel. In self-steering systems, the effort or force required depends on the measured or estimated rack force of the steering system. Accordingly, the hysteresis is determined based on a friction component of the estimated rack force. However, the hysteresis determined in this way can be greater or smaller than the desired hysteresis.

[0038] Systems and methods according to the present disclosure are configured to implement hysteresis shaping techniques to selectively adjust (e.g., increase or decrease) hysteresis to more accurately achieve a desired hysteresis. For example, the reference torque calculator 208 may be configured to implement hysteresis shaping, as described in more detail below.

[0039] Fig. 2B shows an exemplary implementation of the reference torque calculator 208 that includes a hysteresis shaping module 240 according to the present disclosure. As illustrated, an estimated rack load is input to an effort function 244. The effort function 244 may output an effort value based on a lookup table or other function (e.g., by using the estimated rack load as an input). In some examples, the estimated rack load may be modified prior to input to the lookup table by adding a rack / backload value to the estimated rack load. For example, a rack load estimator 248 may be configured to estimate or calculate the estimated rack load, which is then adjusted prior to input to the lookup table of the effort function 244 by adding the rack / backload value to the estimated rack load (e.g.,at a summer 252). In one example, the rack load estimator 248 estimates the rack load based on one or more sensor inputs and / or calculated or modeled values ​​(e.g., a deadband value of the rack force, an estimate of the understeering rack force, the estimated rack force, etc.). In some examples, the rack load may be measured rather than estimated.

[0040] The hysteresis shaping module 240 is configured to independently perform hysteresis addition / increase and hysteresis subtraction / compensation / decrease. For example, when considering a graph of steering effort hysteresis versus rack load, adding effort hysteresis requires a shift in the effort curve along the effort axis. Accordingly, to achieve this shift along the effort axis, an additional hysteresis torque is added to the reference torque emulated by the HWA. As shown in Fig. As shown in Figure 2B, the effort value calculated / output by the effort function 244 corresponds to a desired effort value. The hysteresis shaping module (240) calculates a hysteresis addition value (which can be a positive or negative value) that is added to the desired power value. Accordingly, the reference torque output by the reference torque calculator 208 is modified / shifted according to the hysteresis addition value. The hysteresis addition value can be calculated based on one or more inputs, including, but not limited to, damping, end-of-travel force, etc.

[0041] Conversely, subtracting steering effort hysteresis from rack load requires a shift in the effort curve along the rack load axis when viewing a steering effort versus rack load graph. Accordingly, to achieve this shift along the effort axis, the estimated rack load input to effort function 244 is shifted before being input to effort function 244. Hysteresis shaping module 240, as shown, calculates, for example, a hysteresis subtraction value that is added to the estimated rack load. Accordingly, the estimated rack load provided to effort function 244 is changed / shifted according to the hysteresis subtraction value. The hysteresis addition value may be calculated after one or more inputs, including, but not limited to, rewind, damping, hysteresis compensation, etc.

[0042] In this way, the desired effort for SbW systems (and closed-loop EPS systems) is changed to increase and / or decrease the desired hysteresis perceived by the driver. In one example, separate methods for hysteresis addition and reduction are implemented, as described above in Fig. 2B. This involves modifying the rack force input to the effort function to decrease hysteresis and directly modifying the desired effort to increase hysteresis.

[0043] Fig.3 is a flowchart generally illustrating method 300 for performing hysteresis shaping according to the principles of the present disclosure. For example, one or more computing devices, processors, or processing devices, etc., are configured to execute instructions to implement method 300, such as one or more of the processors of the systems described herein (e.g., a computing device or processor of a vehicle configured to implement controller 100, reference torque calculator 208, etc.). One or more of the steps of method 300 described below may be skipped or omitted in some examples, and / or one or more of the steps may be performed in a different order than described.

[0044] At 304, method 300 includes receiving one or more inputs associated with controlling a handwheel actuator of a vehicle, such as inputs associated with calculating a reference torque. The one or more inputs may include, but are not limited to, an estimated rack force, an estimated rack load, etc.

[0045] At 308, method 300 includes determining whether to perform hysteresis subtraction or hysteresis addition. For example, a desired hysteresis is calculated based on various inputs (e.g., measured, sensed, and / or calculated values). Based on the desired hysteresis, a determination is made whether to perform hysteresis subtraction (i.e., a decrease in hysteresis to achieve the desired hysteresis) or hysteresis addition (i.e., an increase in hysteresis to achieve the desired hysteresis). To perform hysteresis subtraction, method 300 proceeds to 312. To perform hysteresis addition, method 300 proceeds to 316.

[0046] At 312, method 300 includes calculating a hysteresis subtraction value. At 320, method 300 includes combining the hysteresis subtraction value with the estimated rack load to obtain an adjusted estimated rack load. At 324, method 300 includes obtaining an effort value based on the adjusted estimated rack load. At 328, method 300 includes outputting the reference torque based on the effort value.

[0047] At 316, method 300 includes calculating a hysteresis addition value. At 332, method 300 includes obtaining an effort value based on an adjusted estimated rack load. At 336, method 300 includes modifying the effort value based on the hysteresis addition value (e.g., by adding the hysteresis addition value to the effort value). At 340, method 300 includes outputting the reference torque based on the modified effort value (i.e., the effort value modified by the hysteresis addition value).

[0048] The above is intended to illustrate the principles and various embodiments of the present invention. Numerous variations and modifications will become apparent to those skilled in the art once the above disclosure is fully understood. It is intended that the following claims be interpreted to encompass all such variations and modifications.

[0049] The word "example" is used herein to serve as an example, instance, or illustration. Any aspect or design described herein as an "example" is not necessarily to be construed as preferred or advantageous over other aspects or designs. Rather, the use of the word "example" is intended to illustrate concepts in a concrete manner. As used in this application, the term "or" is intended to mean an inclusive "or" rather than an exclusive "or." That is, unless otherwise stated or clear from the context, "X includes A or B" is intended to mean one of the naturally inclusive permutations. That is, if X includes A; X includes B; or X includes both A and B, then "X includes A or B" is satisfied in each of the foregoing cases.Furthermore, as used in this application and the appended claims, the articles "a," "an," and "an" should generally be interpreted to mean "one or more," unless otherwise indicated or the context clearly indicates a singular form. Furthermore, the use of the term "implementation" or "an implementation" does not imply that they are the same embodiment or implementation unless described as such.

[0050] Implementations of the systems, algorithms, methods, instructions, etc. described herein may be realized in hardware, software, or any combination thereof. The hardware may include, for example, computers, intellectual property cores (IP cores), application-specific integrated circuits (ASICs), programmable logic arrays, optical processors, programmable logic controllers, microcode, microcontrollers, servers, microprocessors, digital signal processors, or any other suitable circuitry. In the claims, the term "processor" is to be understood to include any of the foregoing hardware, either individually or in combination. The terms "signal" and "data" are used interchangeably.

[0051] As used herein, the term module can include a packaged functional hardware unit designed for use with other components, a set of instructions executable by a controller (e.g., a processor executing software or firmware), processing circuitry configured to perform a specific function, and a self-contained hardware or software component that interfaces with a larger system. For example, a module can include an application-specific integrated circuit (ASIC), a field-programmable gate array (FPGA), a circuit, a digital logic circuit, an analog circuit, a combination of discrete circuits, gates, and other types of hardware, or a combination thereof.In other embodiments, a module may include memory that stores instructions that can be executed by a controller to implement a feature of the module.

[0052] Furthermore, the systems described herein may be implemented, for example, using a general-purpose computer or a general-purpose processor having a computer program that, when executed, performs any of the methods, algorithms, and / or instructions described herein. Additionally or alternatively, a special-purpose computer / processor including other hardware for executing the methods, algorithms, or instructions described herein may be used.

[0053] Furthermore, all or part of the implementations of the present disclosure may take the form of a computer program product, accessible, for example, from a computer-usable or computer-readable medium. A computer-usable or computer-readable medium may be any device that can, for example, tangibly contain, store, communicate, or transport the program for use by or in connection with any processor. The medium may be, for example, an electronic, magnetic, optical, electromagnetic, or a semiconductor device. Other suitable media are also available.

[0054] The above-described embodiments, implementations, and aspects have been described to facilitate a simple understanding of the present invention and do not limit the present invention. Rather, the invention is intended to encompass various modifications and equivalent arrangements included within the scope of the appended claims, which scope is to be interpreted as broadly as possible to include all modifications and equivalent structuring permitted by law. QUOTES CONTAINED IN THE DESCRIPTION

[0000] This list of documents submitted by the applicant was generated automatically and is included solely for the convenience of the reader. This list is not part of the German patent or utility model application. The DPMA assumes no liability for any errors or omissions. Cited patent literature

[0000] US 63 / 534,392

[0001] US 18 / 318,657

[0030]

Claims

[1] A method for performing hysteresis shaping in a steer-by-wire (SbW) steering system of a vehicle, the method comprising: Determining a desired hysteresis associated with the rotation of a handwheel of the vehicle; Determine, based on the desired hysteresis, whether (i) hysteresis subtraction or (ii) hysteresis addition should be performed; in response to a determination to perform a hysteresis subtraction, (i) calculating a hysteresis subtraction value, (ii) modifying an estimated rack load based on the hysteresis subtraction value, and (iii) generating a reference torque based on the estimated rack load as modified based on the hysteresis subtraction value; in response to the determination to perform hysteresis addition, (i) calculating a hysteresis addition value and (ii) generating the reference torque based on the hysteresis addition value; and Control the handwheel based on the reference torque. [2] The method of claim 1, further comprising providing the estimated rack load as modified based on the hysteresis subtraction value to a cost function and generating a cost value using the cost function. [3] The method of claim 2, further comprising generating the reference torque based on the effort value. [4] The method of claim 1, further comprising providing the estimated rack load to a cost function and generating a cost value using the cost function. [5] The method of claim 4, further comprising generating the reference torque based on the effort value. [6] The method of claim 1, further comprising determining the desired hysteresis based on at least one of (i) a direction of movement of the handwheel and (ii) a determination of whether the driver input to the handwheel is increasing or decreasing. [7] The method of claim 1, further comprising determining the estimated rack load based on an estimated rack force. [8] A system for performing hysteresis shaping in a steer-by-wire (SbW) steering system of a vehicle, the system comprising: Sensors configured to detect a variety of values ​​corresponding to operation of the SbW steering system; and a steering system controller configured to, based on the plurality of detected values, a desired hysteresis is determined in connection with the rotation of a handwheel of the vehicle, based on the desired hysteresis, determines whether (i) a hysteresis subtraction or (ii) a hysteresis addition should be performed, in response to a determination to perform a hysteresis subtraction, (i) calculates a hysteresis subtraction value, (ii) modifies an estimated rack load based on the hysteresis subtraction value, and (iii) generates a reference torque based on the estimated rack load as modified based on the hysteresis subtraction value, in response to a determination to perform hysteresis addition, (i) calculates a hysteresis addition value and (ii) generates the reference torque based on the hysteresis addition value, and controls the handwheel based on the reference torque. [9] The system of claim 8, wherein the steering system controller is further configured to provide the estimated rack load, as modified based on the hysteresis subtraction value, to an effort function and generate an effort value using the effort function. [10] The system of claim 9, wherein the steering system controller is further configured to generate the reference torque based on the effort value. [11] The system of claim 8, wherein the steering system controller is further configured to provide the estimated rack load to an effort function and generate an effort value using the effort function. [12] The system of claim 11, wherein the steering system controller is further configured to generate the reference torque based on the effort value. [13] The system of claim 8, wherein the steering system controller is further configured to determine the desired hysteresis based on at least one of (i) a direction of movement of the handwheel and (ii) a determination of whether the driver input to the handwheel is increasing or decreasing. [14] The system of claim 8, wherein the steering system controller is further configured to determine the estimated rack load based on an estimated rack force. [15] A processor configured to execute instructions stored in memory, wherein execution of the instructions causes the processor to perform hysteresis shaping in a steer-by-wire (SbW) steering system of a vehicle, the instructions comprising: Determining a desired hysteresis in connection with a rotation of a handwheel of the vehicle; Determine, based on the desired hysteresis, whether (i) hysteresis subtraction or (ii) hysteresis addition should be performed; in response to a determination to perform a hysteresis subtraction, (i) calculating a hysteresis subtraction value, (ii) modifying an estimated rack load based on the hysteresis subtraction value, and (iii) generating a reference torque based on the estimated rack load as modified based on the hysteresis subtraction value; in response to the determination to perform hysteresis addition, (i) calculating a hysteresis addition value and (ii) generating the reference torque based on the hysteresis addition value; and Control the handwheel based on the reference torque. [16] The processor of claim 15, wherein the instructions further comprise providing the estimated rack load modified based on the hysteresis subtraction value to a cost function and generating a cost value using the cost function. [17] The processor of claim 16, wherein the instructions further comprise generating the reference torque based on the effort value. [18] The processor of claim 15, wherein the instructions further comprise providing the estimated rack load to a cost function and generating a cost value using the cost function. [19] The processor of claim 18, wherein the instructions further comprise generating the reference torque based on the effort value. [20] The processor of claim 15, wherein the instructions further comprise determining the desired hysteresis based on at least one of (i) a direction of movement of the handwheel and (ii) a determination of whether the driver input to the handwheel is increasing or decreasing.

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