Estimated rack force offset compensation

Abstract

A method for controlling a steering system of a vehicle includes: obtaining a plurality of values corresponding to operation of the steering system; determining an estimated rack force based on the plurality of values; determining a long-term (LT) offset factor of the estimated rack force and a short-term (ST) offset factor of the estimated rack force, respectively; determining a total compensation value based on a combination of the LT offset factor and the ST offset factor; applying the total compensation value to the estimated rack force to obtain a compensated estimated rack force; and controlling at least one function of the steering system using the compensated estimated rack force.

Description

Technical Field

[0001] This disclosure relates to obtaining an accurate estimate of the rack force for a steering system used in a vehicle. Background Technology

[0002] Vehicles (such as cars, trucks, SUVs, crossovers, minivans, ships, aircraft, all-terrain vehicles, recreational vehicles, or other suitable forms of transportation) typically include a steering system, such as an electric power steering (EPS) system, a steer-by-wire (SbW) system, a hydraulic steering system, or other suitable steering system. The steering system of such vehicles typically controls various aspects of the vehicle's steering, including providing steering assistance to the operator and controlling the steerable wheels. Summary of the Invention

[0003] This disclosure generally relates to obtaining an estimated rack force for a steering system used in a vehicle.

[0004] One aspect of the disclosed embodiments includes a method for controlling a steering system of a vehicle. The method includes obtaining a plurality of values ​​corresponding to operation of the steering system; determining an estimated rack force based on the plurality of values; determining a long-term (LT) offset factor and a short-term (ST) offset factor of the estimated rack force, respectively; determining a total compensation value based on a combination of the LT and ST offset factors; applying the total compensation value to the estimated rack force to obtain a compensated estimated rack force; and using the compensated estimated rack force to control at least one function of the steering system.

[0005] In other aspects, a system for controlling one or more steering functions of a vehicle is configured to perform the methods described herein. In other aspects, a processing device is configured to execute instructions stored in a memory to control one or more steering functions of a vehicle as described herein.

[0006] These and other aspects of this disclosure are disclosed in the following detailed description of the embodiments, the appended claims and the accompanying drawings. Attached Figure Description

[0007] This disclosure is best understood by reading in conjunction with the accompanying drawings and through the following detailed description. It should be emphasized that, by convention, the various features in the drawings are not drawn to scale. Instead, for clarity, the dimensions of the various features have been arbitrarily enlarged or reduced.

[0008] Figure 1A A vehicle based on the principles of this disclosure is shown in general.

[0009] Figure 1B A controller based on the principles of this disclosure is shown in general.

[0010] Figure 2 An example rack or wheel actuator controller and a steering wheel actuator controller of a steer-by-wire system according to the principles of this disclosure are generally shown.

[0011] Figure 3 An example implementation of an estimated rack force offset compensation module for a wheel actuator controller according to the principles of this disclosure is generally shown.

[0012] Figure 4 The steps of an example of a rack force offset compensation method estimated according to the principles of this disclosure are generally shown. Detailed Implementation

[0013] The following discussion pertains to various embodiments of this disclosure. While one or more of these embodiments may be preferred, the disclosed embodiments should not be construed as or otherwise used to limit the scope of this disclosure, including the claims. Furthermore, those skilled in the art will understand that the following description has broad application, and the discussion of any embodiment is intended only as an illustrative discussion of that embodiment and not to imply that the scope of this disclosure, including the claims, is limited to that embodiment.

[0014] As mentioned above, vehicles (such as cars, trucks, SUVs, crossovers, minivans, boats, aircraft, all-terrain vehicles, recreational vehicles, or other suitable forms of transportation) typically include steering systems, such as electric power steering (EPS), steer-by-wire (SbW), hydraulic steering, or other suitable steering systems. These steering systems generally control various aspects of the vehicle's steering, including providing steering assistance to the operator and controlling the vehicle's steerable wheels.

[0015] In a SbW steering system, rack force refers to the force transmitted to the vehicle wheels in response to the driver turning the steering wheel (e.g., via a rack and pinion mechanism). The rack force can be calculated or estimated (e.g., as an estimated rack force). The estimated rack force signal can be used to provide accurate steering response, provide driver feedback, improve vehicle stability, and so on.

[0016] Estimated rack force offset or error (i.e., the deviation between the actual rack force and the estimated rack force) can cause traction or other driver feel / feedback problems in vehicles. Estimated rack force offset can be caused by a variety of offset factors, including but not limited to short-term offset factors (such as crowns or other uneven driving surfaces or road conditions, crosswinds, etc.) and long-term offset factors (such as wheel actuator (RWA) system friction, chassis misalignment, offset or error in various input signals (e.g., torque signals, position signals, etc.) and / or other vehicle problems). Therefore, as an indicator of the difference between the actual rack force and the estimated rack force, estimated rack force offset may vary over time and under different vehicle operating conditions.

[0017] As an example, residual position and / or RWA system friction errors cause estimated rack force offsets. These estimated rack force offsets then cause (i) effort offsets, which result in unbalanced steering forces and vehicle traction, and / or (ii) RWA position tracking command offsets, which result in vehicle traction.

[0018] The rack force offset compensation system and method according to this disclosure are configured to determine (e.g., calculate, model, etc.) an accurately estimated rack force offset and control various steering system functions accordingly. As an example, short-term and long-term offset factors are determined separately, such that the estimated rack force offset takes into account the variability of the offset factors.

[0019] In the example implementation, when certain conditions are met (e.g., when the vehicle is traveling in a straight line and various signals / measurements are greater than or less than corresponding thresholds), rack load deviations are filtered out from the various measurement signals before they are converted into steering torque feedback. In other words, the estimated rack force offset is learned during straight-line driving conditions. In this way, offset factors (e.g., both long-term and short-term offset factors) are obtained when the effects of various other inputs are minimized.

[0020] In some examples, the techniques described herein can be combined with active traction compensation features. Example active traction compensation features or functions correct vehicle traction problems by compensating for steering wheel torque offsets detected by the steering system. These torque offsets can include both short-term and long-term offset factors as described herein. When compensation is applied to offset factors, the need for the driver to provide constant input torque to counteract these offsets is greatly reduced.

[0021] As described herein, short-term offset factors can correspond to external conditions of the vehicle. Therefore, short-term correction or compensation values ​​can be determined relatively quickly and applied only during the current ignition cycle. As an example, short-term compensation values ​​or data are not stored between ignition cycles. In some examples, short-term correction data can be reset within the current ignition cycle in response to the detection of changes in driving conditions (e.g., steering wheel torque, steering wheel position, rack position, rack force, lateral acceleration, and / or yaw rate exceeding corresponding thresholds).

[0022] Conversely, long-term offset factors can correspond to vehicle-related issues (e.g., the condition of the vehicle's interior, the corresponding vehicle systems and sensors, etc.). Since long-term offset factors are typically related to the vehicle itself and not to the driving / operating environment, they are corrected relatively slowly (i.e., relative to short-term offset factors). Therefore, long-term compensation values ​​or data can be stored and used in subsequent ignition cycles. In the example, the total offset compensation value is the sum of the short-term compensation value / item and the long-term compensation value / item. The total compensation value can be scaled based on vehicle speed before being applied to the steering system.

[0023] Figure 1A A vehicle 10 according to the principles of this disclosure is generally shown. Vehicle 10 may include any suitable vehicle, such as a car, truck, SUV, minivan, crossover, any other passenger vehicle, any suitable commercial vehicle, or any other suitable vehicle. Although vehicle 10 is illustrated as a wheeled passenger vehicle used on a road, the principles of this disclosure can be applied to other vehicles, such as airplanes, ships, trains, drones, or other suitable vehicles.

[0024] Vehicle 10 includes a body 12 and a hood 14. A passenger compartment 18 is defined at least partially by the body 12. Another portion of the body 12 defines an engine compartment 20. The hood 14 is movably attached to a portion of the body 12 such that when the hood 14 is in a first position or open position, the hood 14 provides access to the engine compartment 20, and when the hood 14 is in a second position or closed position, the hood 14 covers the engine compartment 20. In some embodiments, the engine compartment 20 may be located at the rear of the vehicle 10 (as opposed to what is typically shown).

[0025] The passenger compartment 18 may be located behind the engine compartment 20, but in embodiments where the engine compartment 20 is located at the rear of the vehicle 10, the passenger compartment 18 may be located in front of the engine compartment 20. 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 (e.g., a hybrid vehicle) propulsion system including a combination of an internal combustion engine and one or more electric motors; and / or any other suitable propulsion system.

[0026] In some embodiments, vehicle 10 may include a gasoline engine or a gasoline-fueled engine, such as a spark-ignition engine. In some embodiments, vehicle 10 may include a diesel-fueled engine, such as a compression-ignition engine. Engine compartment 20 houses and / or surrounds at least some components of the propulsion system of vehicle 10. Additionally or optionally, propulsion control devices (e.g., accelerator actuators, brake actuators, steering wheel, and other such components) are disposed in passenger compartment 18 of vehicle 10. The propulsion control devices may be actuated or controlled by the operator of vehicle 10 and may be directly connected to corresponding components of the propulsion system, such as throttle, brakes, axles, vehicle transmission, etc. In some embodiments, the propulsion control devices may transmit signals to a vehicle computer (e.g., drive-by-wire), which in turn may control the corresponding propulsion components of the propulsion system. Thus, in some embodiments, vehicle 10 may be an autonomous vehicle.

[0027] In some embodiments, vehicle 10 includes a transmission communicated with a crankshaft via a flywheel, clutch, or hydraulic coupling. In some embodiments, the transmission includes a manual transmission. In some embodiments, the transmission includes an automatic transmission. In the case of an internal combustion engine or hybrid vehicle, vehicle 10 may include one or more pistons that cooperate with the crankshaft to generate force, which is transmitted via the transmission to one or more axles, causing wheels 22 to rotate. When vehicle 10 includes one or more electric motors, a vehicle battery and / or fuel cell provides energy to the electric motors to rotate the wheels 22.

[0028] Vehicle 10 may include an autonomous vehicle propulsion system, such as cruise control, adaptive cruise control, automatic braking control, other autonomous vehicle propulsion systems, or combinations thereof. Vehicle 10 may be an autonomous or semi-autonomous vehicle, or other suitable type of vehicle. Vehicle 10 may include additional or fewer structures compared to the structures generally shown and / or disclosed herein.

[0029] In some embodiments, 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), and a local interconnect component (LIN) 32. Vehicle 10 may use the CAN bus 26, MOST 28, FlexRay component 30, LIN 32, other suitable network or communication systems, or combinations thereof, to transmit various information from sensors, such as those inside or outside the vehicle, to various processors or controllers, such as those inside or outside the vehicle. Vehicle 10 may include additional or fewer features compared to those generally shown and / or disclosed herein.

[0030] In some embodiments, the vehicle 10 may include a steering system, such as an EPS system, a steer-by-wire system (e.g., which may include or be connected to one or more controllers that control components of the steering system without using a mechanical connection between the steering wheel and the wheels 22 of the vehicle 10), a hydraulic steering system (e.g., which may include a magnetic actuator incorporated into a valve assembly of a hydraulic steering system), or other suitable steering systems.

[0031] A steering system may include an open-loop feedback control system or mechanism, a closed-loop feedback control system or mechanism, or a combination thereof. The steering system may be configured to receive various inputs, including but not limited to: steering wheel position, input torque, one or more wheel positions, other suitable inputs or information, or a combination thereof.

[0032] Additionally or alternatively, inputs may include steering wheel torque, steering wheel angle, motor speed, vehicle speed, estimated motor torque command, other suitable inputs, or combinations thereof. The steering system may be configured to provide steering functionality and / or control to the vehicle 10. For example, the steering system may generate auxiliary torque based on various inputs. The steering system may be configured to use the auxiliary torque to selectively control the motor of the steering system to provide steering assistance to the operator of the vehicle 10.

[0033] In some embodiments, the vehicle 10 may include a controller, such as controller 100, as... Figure 1BThe controller 100 may include any suitable controller, such as an electronic control unit or other suitable controller. For example, the controller 100 may be configured to control 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 suitable number of processors other than or excluding the processor 102. The memory 104 may include a single disk or multiple disks (e.g., a hard disk drive) and includes a storage management module that manages one or more partitions within the memory 104. In some embodiments, the memory 104 may include flash memory, semiconductor (solid-state) memory, etc. The memory 104 may include random access memory (RAM), read-only memory (ROM), or a combination thereof. The memory 104 may include instructions that, when executed by the processor 102, cause the processor 102 to control at least various aspects of the 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.

[0034] The controller 100 may receive one or more signals from various measuring devices or sensors 106, which indicate sensed or measured characteristics of the vehicle 10. Sensors 106 may include any suitable sensors, measuring devices, and / or other suitable mechanisms. For example, sensors 106 may include one or more torque sensors or devices, one or more steering wheel 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 combinations thereof. One or more signals may indicate steering wheel torque, steering wheel angle, motor speed, vehicle speed, other suitable information, or combinations thereof.

[0035] In some embodiments, controller 100 may be configured to implement the estimated rack force offset compensation system and method of this disclosure. However, the systems and methods implemented by controller 100 described herein are not intended to be limiting, and any type of software executing on the controller or processor may perform the methods 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 perform the methods described herein.

[0036] Figure 2An example rack or RWA controller 200 and a column or steering wheel actuator (HWA) controller 204 according to the present disclosure are illustrated. For example, the HWA controller 204 is configured to generate a steering wheel actuator (HWA) motor torque command 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, steering wheel position, and steering wheel speed). The RWA controller 200 is configured to determine the estimated rack force based on the actual rack position (e.g., a signal indicating the actual rack position) and a rack position reference signal (e.g., a rack position reference indicating a target rack position).

[0037] As an example, the HWA controller 204 includes a reference torque calculator 208 configured to calculate a reference torque based on an estimated rack force and one or more other input signals. For example, the reference torque corresponds to the sum of various input / measurement results (e.g., force, hysteresis, damping return, catch, etc.). A closed-loop (e.g., PID closed-loop) torque controller 212 is configured to generate and output a motor torque command based at least in part on the reference torque. The motor torque command is provided as a control signal to control the motor of the steering wheel actuator.

[0038] The estimated rack force corresponds to the target value of the motor torque command. Therefore, the estimated rack force (and any estimated rack force offset or error) is a key factor in determining the force provided by the motor of the steering wheel actuator.

[0039] In some examples, the HWA controller 204 may also include a C-factor lookup module 216 and a rack position reference calculator 220. For example, the rack position reference calculator 220 is configured to generate a rack position reference based on a C-factor received from the C-factor lookup module 216. The C-factor may be determined based on a steering wheel angle (“HwAg”) corresponding to a driver input (e.g., a steering wheel angle indicating the driver’s intention conveyed via the steering wheel). An example system and method for obtaining a rack position reference and a C-factor are described in more detail in U.S. Patent Application No. 18 / 318,657, filed May 16, 2023, the entire contents of which are incorporated herein by reference.

[0040] RWA controller 200 includes rack position controller 224 (e.g., PID rack position controller) configured to generate one or more rack position control signals based on the actual rack position and a rack position reference (e.g., based on the difference between the actual rack position and the rack position reference). For example, the rack position control signals may include, but are not limited to, rack motor speed and motor torque commands (e.g., signals indicating the amount of torque applied by the driver). In this way, the rack position is controlled to follow the driver's intention (as indicated by the rack reference position).

[0041] The rack force predictor 228 generates an estimated rack force based on the output of the rack position controller 224 (e.g., a function based on rack motor speed, rack motor torque command, etc.). In various examples, the estimated rack force can be calculated based on the amount of torque applied to the steering wheel by the driver (e.g., indicated by rack motor torque command, various sensor signals, etc.).

[0042] As described herein, estimated rack forces typically include offsets or errors (e.g., estimated rack force offset). The RWA controller 200 according to this disclosure includes an offset compensation module 232 configured to determine the accurately estimated rack force offset (compensated estimated rack force offset) and modify the estimated rack force accordingly, as described in more detail below.

[0043] Figure 3 An example implementation of the offset compensation module 232 is shown. In some examples, the offset compensation module 232 is configured to acquire long-term and short-term offset factors during a learning mode or period. For example, learning the long-term and short-term offset factors may depend on meeting one or more activation conditions. Activation conditions may correspond to driving conditions and vehicle conditions that allow for accurate calculation of the long-term and short-term offset factors and minimize changes. Activation criteria may include, but are not limited to:

[0044] The maximum steering wheel torque is less than the threshold.

[0045] The steering wheel angle is less than the threshold.

[0046] The rack position is less than the threshold.

[0047] The steering wheel angle and rack position calculations satisfy their respective minimum confidence values;

[0048] The steering wheel speed is less than the threshold.

[0049] The rack speed is less than the threshold.

[0050] The vehicle speed is within a predetermined range (e.g., between a minimum threshold and a maximum threshold);

[0051] The rate of change of vehicle speed is less than the threshold.

[0052] The lateral speed of the vehicle is less than the threshold.

[0053] The vehicle's yaw rate is less than the threshold; and

[0054] The rack force is less than the threshold.

[0055] In some examples, in response to the satisfaction of selected enable conditions (e.g., some or all of the conditions listed above), offset compensation module 232 obtains long-term (LT) and short-term (ST) offset factors based on the estimated rack force and various other input signals (sensor signals, measurement signals, etc.). For example, offset compensation module 232 includes LT filter module 304 and ST filter module 308, which may correspond to corresponding low-pass filters or filter circuits. Each of filter modules 304 and 308 filters out different low-frequency elements corresponding to the estimated rack force to obtain the corresponding LT and ST offset factors. For example, filter modules 304 and 308 correspond to low-pass filters with different gains and cutoff frequencies. Thus, LT filter module 304 can learn the LT offset factor during a first learning cycle, while ST filter module 308 generates the ST offset factor learned during a second learning cycle, which is shorter than the first learning cycle. The first and second learning cycles may be defined by their respective calibration values.

[0056] In the example, the output of the LT filter module 304 (i.e., the LT offset factor) is the result of filtering out low-frequency elements of the estimated rack force and may include higher-frequency elements associated with the ST error. Conversely, the output of the ST filter module 304 is the result of filtering out both low-frequency elements of the estimated rack force and elements associated with the LT error. In other words, the ST filter module 308 may have a higher frequency than the LT filter module 304.

[0057] The LT offset factor and ST offset factor are provided to the LT offset compensation module 312 and the ST offset compensation module 316, respectively, and the LT offset compensation module 312 and the ST offset compensation module 316 output LT offset compensation value and ST offset compensation value, respectively. The LT offset compensation value and ST offset compensation value are calculated based on the LT offset factor and the ST offset factor. The LT compensation value and the ST compensation value are combined (e.g., summed at the summing module 320) to generate a compensated estimated rack force offset. The estimated rack force is modified / adjusted based on the compensated estimated rack force offset. For example, according to this disclosure, the compensated estimated rack force offset is subtracted from the estimated rack force (or in some instances, the compensated estimated rack force offset is added to the estimated rack force) to obtain the compensated estimated rack force. As described above, the compensated estimated rack force is provided to the HWA controller 204 to calculate the motor torque command.

[0058] In some examples, the compensated estimated rack force offset may be scaled based on vehicle speed (e.g., multiplied by a scaling factor that increases with speed) and / or not applied at vehicle speeds below a threshold.

[0059] Figure 4 This is a flowchart generally illustrating a rack force offset compensation method 400 estimated according to the principles of this disclosure. For example, one or more computing devices, processors, or processing devices (such as one or more processors of the system described herein (e.g., computing devices or processors of a vehicle configured to implement offset compensation module 232 and / or other components of RWA controller 200, HWA controller 204, etc.)) are configured to execute instructions to implement method 400.

[0060] At 404, method 400 includes determining whether one or more enabling conditions for learning the LT offset factor and ST offset factor, as described herein, are met. If yes, method 400 proceeds to 408. If no, method 400 may repeat the determination performed at 404 until one or more enabling conditions are met.

[0061] At 408, method 400 includes learning the LT offset factor and the ST offset factor, as described herein. For example, offset compensation module 232 applies filtering or other processing techniques to isolate and identify the LT offset and ST offset respectively (e.g., using appropriate filter modules).

[0062] At 412, method 400 includes determining LT offset compensation values ​​and ST offset compensation values ​​based on LT offset factors and ST offset factors. At 416, method 400 includes applying the LT compensation values ​​and ST compensation values ​​to the estimated rack force. For example, the LT compensation values ​​and ST compensation values ​​are combined (e.g., summed) to obtain a compensated estimated rack force offset, and then the estimated rack force is subtracted from the compensated estimated rack force offset (or the compensated estimated rack force offset is added to the estimated rack force) to obtain the compensated estimated rack force.

[0063] At 420, one or more vehicle functions are controlled based on a compensated, estimated rack force. For example, the compensated, estimated rack force is used to control at least one function of the steering system, such as controlling the torque of a motor or motor actuator, as described herein.

[0064] The foregoing discussion is intended to illustrate the principles and various embodiments of the invention. Many variations and modifications will become apparent to those skilled in the art once the foregoing disclosure is fully understood. The appended claims are intended to be construed as covering all such variations and modifications.

[0065] The word “example” is used herein to mean used as an example, illustration, or description. Any aspect or design described herein as an “example” is not necessarily to be construed as being more preferred or advantageous than other aspects or designs. Rather, the use of the word “example” is intended to present a concept in a specific 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 clearly apparent from the context, “X comprises A or B” is intended to mean any natural inclusion. That is, if X comprises A; X comprises B; or X comprises both A and B, then “X comprises A or B” is satisfied in any of the foregoing cases. Additionally, the article “a / an” used in this application and the appended claims should generally be interpreted as meaning “one or more” unless otherwise stated or clearly apparent from the context to the singular form. Furthermore, unless so described, the use of the terms “implementation” or “an embodiment” throughout the document is not intended to refer to the same embodiment or implementation.

[0066] Unless the context clearly indicates otherwise, as used herein, “a,” “one,” and “the” refer to both singular and plural objects. By way of example, a “processor” programmed to perform various functions means a processor programmed to perform each function, or more than one processor collectively programmed to perform each of the various functions.

[0067] The systems, algorithms, methods, and instructions described herein can be implemented in hardware, software, or any combination thereof. Hardware may include, for example, a computer, intellectual property (IP) core, application-specific integrated circuit (ASIC), programmable logic array, optical processor, programmable logic controller, microcode, microcontroller, server, microprocessor, digital signal processor, or any other suitable circuit. In the claims, the term "processor" should be understood to include any of the foregoing hardware, individually or in combination. The terms "signal" and "data" are used interchangeably.

[0068] 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), circuitry, digital logic circuitry, analog circuitry, a combination of discrete circuitry, gate circuits, and other types of hardware, or combinations thereof. In other embodiments, a module can include a memory storing instructions executable by a controller to implement the features of the module.

[0069] Furthermore, in one respect, for example, the system described herein may be implemented using a general-purpose computer or general-purpose processor having a computer program that, when executed, implements any of the corresponding methods, algorithms, and / or instructions described herein. Additionally or alternatively, for example, a special-purpose computer / processor may be utilized, which may contain additional hardware for implementing any of the methods, algorithms, or instructions described herein.

[0070] Furthermore, all or part of the embodiments of this disclosure may take the form of a computer program product accessible from, for example, a computer-usable or computer-readable medium. A computer-usable or computer-readable medium may be, for example, any means capable of tangibly containing, storing, conveying, or transmitting a program for use by or in conjunction with any processor. The medium may be, for example, an electrical, magnetic, optical, electromagnetic, or semiconductor device. Other suitable media may also be used.

[0071] The embodiments, implementations, and aspects described above are intended to allow for an easy understanding of the invention and do not limit the invention. Rather, the invention is intended to cover various modifications and equivalent arrangements included within the scope of the appended claims, which should be given the broadest interpretation to cover all such modifications and equivalent structures permitted by law.

Claims

1. A method for controlling a steering system of a vehicle, the method comprising: Obtain multiple values ​​corresponding to the operation of the steering system; The estimated rack force is determined based on the aforementioned values; The long-term LT offset factor and the short-term ST offset factor of the estimated rack force are determined respectively. The total compensation value is determined based on the combination of the LT offset factor and the ST offset factor; The total compensation value is applied to the estimated rack force to obtain the compensated estimated rack force; as well as The compensated, estimated rack force is used to control at least one function of the steering system.

2. The method according to claim 1, further comprising: The estimated rack force is determined based on the rack position reference.

3. The method according to claim 2, further comprising: The estimated rack force is determined based on the difference between the rack position reference and the actual rack position.

4. The method according to claim 1, further comprising: The steering wheel motor torque is controlled based on the compensated estimated rack force.

5. The method according to claim 1, wherein, Determining the LT offset factor and the ST offset factor includes applying a filter to the estimated rack force.

6. The method according to claim 5, wherein, The filtering includes using different low-pass filters to determine the LT offset factor and the ST offset factor, respectively.

7. The method according to claim 1, further comprising: Determine whether one or more enable conditions are met, and determine the LT offset factor and the ST offset factor respectively in response to determining that the one or more enable conditions are met.

8. A system for controlling one or more steering functions of a vehicle, the system comprising: One or more sensors are configured to acquire multiple values ​​corresponding to the one or more steering functions; as well as The controller is configured as follows: The estimated rack force is determined based on the aforementioned values. The long-term LT offset factor and the short-term ST offset factor of the estimated rack force are determined respectively. The total compensation value is determined based on the combination of the LT offset factor and the ST offset factor. The total compensation value is applied to the estimated rack force to obtain the compensated estimated rack force, and The compensated, estimated rack force is used to control the one or more steering functions.

9. The system according to claim 8, wherein, The controller is configured to determine the estimated rack force based on a rack position reference.

10. The system according to claim 9, wherein, The controller is configured to determine the estimated rack force based on the difference between the rack position reference and the actual rack position.

11. The system according to claim 8, wherein, The controller is configured to control the steering wheel motor torque based on the compensated, estimated rack force.

12. The system according to claim 8, wherein, Determining the LT offset factor and the ST offset factor includes applying a filter to the estimated rack force.

13. The system according to claim 12, wherein, The filtering includes using different low-pass filters to determine the LT offset factor and the ST offset factor, respectively.

14. The system according to claim 8, wherein, The controller is configured to determine whether one or more enable conditions are met, and in response to determining that the one or more enable conditions are met, to determine the LT offset factor and the ST offset factor respectively.

15. A processing apparatus configured to execute instructions stored in a memory to control one or more steering functions of a vehicle, the instructions comprising: Obtain multiple values ​​corresponding to the one or more steering functions; The estimated rack force is determined based on the aforementioned values; The long-term LT offset factor and the short-term ST offset factor of the estimated rack force are determined respectively. The total compensation value is determined based on the combination of the LT offset factor and the ST offset factor; The total compensation value is applied to the estimated rack force to obtain the compensated estimated rack force; as well as The compensated, estimated rack force is used to control the one or more steering functions.

16. The processing apparatus according to claim 15, wherein, The instructions include determining the estimated rack force based on a rack position reference.

17. The processing apparatus according to claim 16, wherein, The instruction includes determining the estimated rack force based on the difference between the rack position reference and the actual rack position.

18. The processing apparatus according to claim 15, wherein, The instructions include controlling the steering wheel motor torque based on the compensated estimated rack force.

19. The processing apparatus according to claim 15, wherein, Determining the LT offset factor and the ST offset factor includes applying filtering to the estimated rack force, wherein the filtering includes using different low-pass filters to determine the LT offset factor and the ST offset factor, respectively.

20. The processing apparatus according to claim 15, wherein, The instruction includes determining whether one or more enable conditions are met, and determining the LT offset factor and the ST offset factor respectively in response to determining that the one or more enable conditions are met.

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