STEERING SYSTEM FOR ELECTROMECHANICAL STEERING (SBW STEERING SYSTEM) OF A VEHICLE

Abstract

An electromechanical steering system (SBW steering system) of a vehicle comprises: a steering feel motor configured to apply torque to a steering column and steering wheel; a steering actuator motor configured to turn the vehicle's wheels; a steering assessment module configured to issue commands for a strength assessment of a driver; an infotainment module configured, based on the commands, to issue a command to the driver to hold the steering wheel at a first predetermined angle, which is an angle either counterclockwise or counterclockwise with respect to a second predetermined angle;and a steering actuator module configured, based on commands, to control the steering feel motor and to output a predetermined torque to the steering column and steering wheel in one direction from counterclockwise to counterclockwise for a predetermined period of time, overlapping with the command for the driver to hold the steering wheel at the first predetermined angle.

Description

INITIATIONThe present invention relates to vehicle control systems and, more particularly, to a steering system according to the preamble of claim 1 for electro-mechanical steering (SBW) of a vehicle.A steering system according to the preamble of claim 1 is substantially known from DE 10 2019 208 732 A1.Similar systems are disclosed in the publications DE 10 2017 217 115 A1, DE 10 2005 030 934 A1 and DE 10 2019 004 864 A1 for electromechanical steering.Vehicles include one or more torque-generating devices, such as an internal combustion engine and / or an electric motor. A passenger of a vehicle travels in a passenger cabin (or a passenger compartment) of the vehicle.Vehicles may include one or more different types of sensors that sense the vehicle environment. An example of a sensor that detects the vehicle environment is a camera configured to capture images of the vehicle environment. Examples of such cameras include forward cameras, rearward cameras, and side cameras. Another example of a sensor that detects the vehicle environment includes a radar sensor configured to receive information regarding the vehicle environment. Further examples of sensors that sense the vehicle environment include sonar sensors and light detection and ranging (LIDAR) sensors configured to capture information regarding the vehicle environment.The invention is based on the object of improving a steering system for electromechanical steering of a vehicle to the extent that a driver actuating the steering system experiences as much as possible the same steering behavior as in the case of purely mechanical steering.SUMMARYThis object is achieved with a steering system having the features of claim 1 for electromechanical steering of a vehicle. Advantageous further developments are evident from the dependent claims.According to further features, the muscle parameters optionally include a muscle spring of the driver.In further features, the muscle parameters optionally include a driver attenuation coefficient.In further features, the muscle parameters optionally include a mass coefficient of the driver.In further features, the strength assessment module is optionally configured to determine the muscle parameters using either an equation or a look-up table that relates a steering wheel angle to muscle parameters.In further features, the strength assessment module is optionally configured to determine the muscle parameters using the following equation: where J is a muscle spring value of the driver, a second derivative of the steering wheel angle, d is a muscle attenuation value of the driver, θdc is a first derivative of the steering wheel angle, k is a muscle mass coefficient of the driver, θ is the steering wheel angle, and τ is the predetermined torque.In further features, the strength assessment module is optionally configured to determine the muscle parameters using least squares.In further features: the steering assessment module is optionally configured to determine a driver strength level based on the muscle parameters; and the steering actuator module is optionally configured to: determine steering parameters based on the strength level and control the torque output of the steering feel motor during driving of the vehicle based on the steering parameters.In further features, the steering parameters optionally include a power assist gain provided by the steering feel motor.In further features, the steering parameters optionally include a linearity gain provided by the steering feel motor.In further features, the steering parameters optionally include a steering stiffness provided by the steering feel motor.In further features, the steering parameters optionally include steering wheel damping provided by the steering feel motor.In further features, the steering parameters optionally include a steering ratio provided by the steering feel motor.In further features, the steering assessment module is optionally configured to determine steering features based on the driver's muscle parameters; and the infotainment module is configured to output a graphical illustration of the steering features.In further features, the graphical illustration is optionally a spider diagram.According to further features, the steering features optionally include a steering effort.In further features, the steering features optionally include steering feedback.In further features, the steering features optionally include directivity and sensitivity.In further features, the steering features optionally include center traceability and linearity.Further described is an electro-mechanical steering (SBW) steering method for a vehicle, comprising: by a steering feel motor, applying a torque to a steering column and a steering wheel; actuating one or more steering components and turning the wheels of the vehicle; outputting commands for a strength rating of a driver of the vehicle; based on the commands for the strength rating, outputting a command to the driver to maintain the steering wheel at a first predetermined angle, which is an angle either counterclockwise or counterclockwise with respect to a second predetermined angle; based on the commands for the strength judgment, controlling the steering feel motor and outputting a predetermined torque to the steering column and the steering wheel by the other of counterclockwise and a counterclockwise direction for a predetermined period of time overlapping with the command for the driver to maintain the steering wheel at the first predetermined angle; determining muscle parameters of the driver based on steering wheel angle measurements taken during the predetermined period of time; and controlling the torque output of the steering feel motor during driving of the vehicle based on the muscle parameters of the driver.Further areas of applicability of the present invention will become apparent from the detailed description, claims and drawings. The detailed description and specific examples are provided for illustrative purposes only.BRIEF DESCRIPTION OF THE DRAWINGSThe present invention will be more fully understood from the detailed description and the accompanying drawings, in which: FIG. 1 is a functional block diagram of an example vehicle system; FIG. 2 is a functional block diagram of an exemplary implementation of a steering system for electro-mechanically steering the vehicle; FIG. 3 is a functional block diagram of an example implementation of a steering control module; FIG. 4 is a flow chart illustrating an exemplary method for performing a driver's severity assessment; FIG. 5 is an example graph of steering wheel angle, torque, and grip force versus time for strength evaluation; FIG. 6 is a flowchart illustrating an exemplary method of controlling the steering feel motor based on the driver's muscle parameters determined based on the driver's severity judgment; FIG. 7 is an exemplary table illustrating steering features and corresponding steering parameters; and FIG. 8 is an exemplary graphical illustration of steering features for various drivers.In the drawings, reference numerals may be used multiple times to identify similar and / or similar elements.DETAILED DESCRIPTIONA vehicle includes a steering system such as an electro-mechanical steering (SBW) steering system. In SBW systems, a steering column coupled to a steering wheel is not mechanically coupled to the components that turn the wheels of the vehicle. Instead, a steering actuator motor actuates the components turning the wheels of the vehicle based on a rotational angle of the steering wheel / column or a steering rack position. A steering feel motor applies torque to the steering column in an effort to replicate which a driver would feel if the steering column were mechanically coupled to the components in a non-SBW steering system.The present application includes performing a strength judgment of a driver of a vehicle including an SBW steering system. The severity rating may include instructing the driver to maintain the steering wheel at a predetermined position and applying a negative torque to the steering wheel. A severity assessment module determines driver muscle parameters based on steering wheel measurements taken during the severity assessment. A steering control module controls the steering feel motor based on the driver's muscle parameters to match the driver's muscle parameters using the steering wheel, which the driver feels. This improves driver experience and improves adjustability.Referring now to FIG. 1, a functional block diagram of an example vehicle system is presented. While a vehicle system for a hybrid vehicle is shown and described, the present application is also applicable to non-hybrid vehicles, electric vehicles, fuel cell vehicles, and other types of vehicles. The present application is applicable to autonomous vehicles, semi-autonomous vehicles, non-autonomous vehicles, shared vehicles, non-shared vehicles, and other types of vehicles.An engine 102 may combust an air / fuel mixture to generate drive torque. An engine control module (ECM) 106 controls the engine 102. For example, the ECM 106 may control actuation of engine actuators such as a throttle, one or more spark plugs, one or more fuel injectors, valve actuators, camshaft phasers, an exhaust gas recirculation (EGR) valve, one or more boosting devices, and other suitable engine actuators. In some types of vehicles (e.g., electric vehicles), the engine 102 may be omitted.The engine 102 may output torque to a transmission 110. A transmission control module (TCM) 114 controls operation of the transmission 110. For example, the TCM 114 may control a gear selection in the transmission 110 and one or more torque-transmitting devices (e.g., a torque converter, one or more clutches, etc.).The vehicle system may include one or more electric motors. For example, an electric motor 118 may be implemented in the transmission 110, as shown in the example of FIG. 1. An electric motor may operate at a fixed time as either a generator or a motor. When operating as a generator, an electric motor converts mechanical energy into electrical energy. The electrical energy may be used, for example, to charge a battery 126 via a power control device (PCD) 130. When operating as a motor, an electric motor generates torque that may be used, for example, to supplement or replace torque output by the engine 102. While the example of an electric motor is provided, the vehicle may include zero or more than one electric motor.A power inverter module (PIM) 134 may control the electric motor 118 and the PCD 130. The PCD 130 applies power from the battery 126 to the electric motor 118 based on signals from the PIM 134, and the PCD 130 provides power output by the electric motor 118, e.g., to the battery 126. The PIM 134 may include, for example, an inverter.A steering control module 140 controls steering / steering of wheels of the vehicle based on, for example, driver turning of a steering wheel in the vehicle and / or steering instructions from one or more vehicle control modules. A steering wheel angle sensor (FIG. 2 ) may monitor a rotational position of the steering wheel and generates a steering wheel angle 142 based on the position of the steering wheel. As an example, the steering control module 140 may control vehicle steering using an electronic power steering (EPS) motor 144 based on the steering wheel angle 142. However, the vehicle may include another type of steering system. The present application includes an electro-mechanical steering (SBW) steering system. A torque sensor (FIG. 2 ) may measure a torque that the driver applies to the steering wheel.A brake control module 150 may selectively control (e.g., friction) brakes 154 of the vehicle based on one or more driver inputs, such as a brake pedal position (BPP) 170. Another driver input may be cruise control input 153 from a cruise control module 155 when cruise control is enabled.Modules of the vehicle may share parameters via a network 162, such as a controller area network (CAN). A CAN may also be referred to as a vehicle area network. For example, network 162 may include one or more data buses. Various parameters may be made available by a given module to other modules via network 162.For example, the driver inputs may include an accelerator pedal position (APP) 166 that may be provided to the ECM 106. The BPP 170 may be provided to the brake control module 150. A park, reverse, neutral, drive (PRNDL) position 174 may be provided to the TCM 114. An ignition state 178 may be provided to a body control module (BCM) 180. For example, the ignition state 178 may be input by a driver via an ignition key, key, or ignition switch. At a specified time, the ignition state 178 may be one of off, accessory, operation, or cranking.An infotainment module 183 may output various information using one or more output devices 184. The output devices 184 may include, for example, one or more display devices (a non-touch screen and / or a touch screen), one or more other suitable types of video output devices, one or more speakers, one or more haptic devices, and / or one or more other suitable types of output devices.The infotainment module 183 may output video via the one or more display devices. The infotainment module 183 may output audio via the one or more speakers. Infotainment module 183 may output further feedback using one or more haptic devices. For example, haptic devices may be included in one or more seats, one or more seatbelts, steering wheel, etc. Examples of display devices may include, for example, one or more display devices (e.g., on a front console) of the vehicle, a windshield display device (HUD) that displays information via a substrate (e.g., a windshield), one or more display devices that slope downward or extend upward to form panoramic views, and / or one or more other suitable display devices.The vehicle may include a plurality of exterior sensors and cameras, generally illustrated by 186 in FIG. 1. One or more actions may be taken based on input from the exterior sensors and cameras 186. For example, the infotainment module 183 may display video, various views, and / or alarms on a display via input from the exterior sensors and cameras 186 during driving.As another example, the brake control module 150 and / or the steering control module 140 may apply the brakes 154 and / or steer the vehicle to prevent the vehicle from colliding with an object around the vehicle.The vehicle may include one or more additional control modules not shown, such as a chassis control module, a battery pack control module, etc. The vehicle may omit one or more of the control modules shown and discussed.FIG. 2 is a functional block diagram of an example implementation of a steering system for electro-mechanically steering the vehicle. A driver turns a steering wheel 204 to input requests to steer / turn the vehicle. For example, the driver may turn the steering wheel 204 clockwise to input a request to turn the vehicle right. The driver may turn the steering wheel 204 increasingly clockwise to input a request to turn the vehicle more clockwise. The driver may turn the steering wheel 204 counterclockwise to input a request to turn the vehicle leftward. The driver may turn the steering wheel 204 increasingly counterclockwise to input a request to turn the vehicle more left-hand. A grip strength sensor 208 may be included in the steering wheel 204 and measure a grip strength of a driver on the steering wheel 204.The steering wheel 204 is coupled to a steering column 212. The steering column 212 rotates with the steering wheel 204. A steering wheel angle sensor 216 measures a rotational position / angle of the steering wheel 204, e.g., based on a rotation of the steering column 212.An actuator 220 surrounds the steering column 212. A steering feel motor 224 controls steering parameters felt by the driver via the steering wheel 204, e.g., by actuating the actuator 220. The steering feel motor 224 applies a torque that can be felt by the driver via the steering wheel 204. A torque sensor 228 may measure torque output from the steering feel motor 224. The steering control module 140 controls the steering feel motor 224, e.g., by controlling an electric power applied to the steering feel motor 224.Wheels 232 such as front wheels of the vehicle are coupled to one or more steering levers 236. Movement of the one or more steering levers 236 moves the wheels leftward and rightward to steer the vehicle leftward and rightward.A steering actuator motor 240 controls movement of the one or more steering levers 236 via an actuator 244 and a second steering column 248. For example, the actuator 244 may surround the second steering column 248. The steering actuator motor 240 outputs torque to the second steering column 248 via the actuator 244, and the torque at the second steering column 248 moves the one or more steering levers 236. While the example of the second steering column 248 is provided, the present application is also applicable to other actuators such as a belt or ball screw drive.The steering control module 140 controls the steering actuator motor 240, e.g., by controlling an electrical power applied to the steering actuator motor 240. The steering control module 140 controls the steering actuator motor 240 based on, e.g., the steering wheel angle 142 to steer the vehicle based on the steering wheel angle 142.As illustrated in FIG. 2, the steering column 212 and the second steering column 248 are not physically connected and can rotate independently of each other.FIG. 3 is a functional block diagram of an example implementation of the steering control module 140. A severity assessment module 304 performs a severity assessment of the driver and determines muscle parameters (e.g., muscle spring, muscle attenuation, and muscle mass coefficient) based on steering wheel (SW) measurements 308 measured [recorded] during the severity assessment. The SW measurements 308 may include, for example, the steering wheel angle 142, the torque measured by the sensor 228, and a grip strength measured by the grip strength sensor 208.The severity assessment module 304 determines a severity level of the driver based on the muscle parameters, such as using a look-up table that relates muscle parameters to severity levels. The strength level and muscle parameters are collectively illustrated by 312 (strength parameters).A user identification module 316 identifies the driver using one or more biometric inputs 320 of a driver. Examples of the driver biometric inputs 320 include one or more images including a face of the driver and captured using a camera, a touch input (e.g., a fingerprint) of the driver captured using a touch sensor, one or more voice / voice inputs of the driver captured using one or more microphones, and / or one or more inputs that can be used to identify the driver. The user identification module 316 may identify the driver by matching one or more of a driver's biometric inputs 320 with one or more stored biometric parameters for different drivers (e.g., closest match). If no matching occurs (e.g., confidence of the matching<pre-determined value), the user identification module 316 may generate a new profile for a new driver and store the collected biometric parameters associated with the new driver. The user identification module 316 outputs an indicator 324 that indicates the driver that was identified.A wireless transmitting / receiving device module 328 wirelessly transmits and receives data from a remote server 332 via one or more antennas 336. For example, the wireless transmitting / receiving device module 328 sends the indicator 324 to the remote server 332 along with the driver's strength parameters 312. The remote server 332 stores the strength parameters 312 associated with the driver. The remote server 332 may communicate one or more diseases to the driver, e.g., based on changes and / or trends over time of one or more of the driver's strength parameters. The wireless transmitting / receiving device module 328 may communicate with the remote server 332, for example, using a cellular network, a Wi-Fi network, a satellite network, or another suitable type of wireless communication network.In various implementations, one or more user computing devices 340 may communicate with the remote server 332, e.g., to view, update, enter, and / or delete stored information associated with the driver's profile. Examples of user computing devices include cellular phones, tablet devices, computers, smart watches, and other types of devices.A steering actuator module 344 controls the torque output, such as the magnitude and direction of the steering feel motor 224 and the steering actuator motor 240. For example, the steering actuator module 344 may control power applied to the steering feel motor 224 and the steering actuator motor 240 from one or more batteries, such as the battery 352. For example, during driving of the vehicle, the steering actuator module 344 controls the steering actuator motor 240 based on the steering wheel angle 142 to steer the vehicle according to the driver's rotation of the steering wheel 204. During driving, the steering actuator module 344 also controls the steering feel motor 224 based on one or more of the strength parameters (e.g., the strength level) to control what the driver feels during driving using the steering wheel 204.The steering actuator module 344 also controls the steering feel motor 224 in accordance with commands 348 from the severity evaluation module 304 to perform the severity evaluation. Infotainment module 183 also outputs information according to instructions 348 via one or more of output devices 184 (e.g., acoustically via one or more speakers, optically via one or more display devices) to perform the severity assessment. The starch rating is further discussed below.FIG. 4 is a flow chart illustrating an example method for performing the strength assessment. At 404, the severity evaluation module 304 generates the commands 348 for the infotainment module 183 and the steering actuator module 344. Additionally, at 404, the infotainment module 183 outputs one or more commands in the cabin (e.g., audibly via one or more speakers, visually via one or more display devices) that the driver is holding the steering wheel 204 at a predetermined non-zero steering wheel angle, in accordance with the commands 348. Therefore, the driver should maintain the steering wheel 204 at the predetermined steering wheel angle that is to the left or right of the steering wheel angle zero. The vehicle travels forward in the direction of the longitudinal axis of the vehicle when it is zero at the steering wheel angle. The predetermined steering wheel angle may be positive or negative and may be, for example, in the range of 15 to 90 degrees or another suitable angle. Positive steering wheel angles may be zero clockwise with respect to the steering wheel angle and negative steering wheel angles may be zero counter-clockwise with respect to the steering wheel angle, or vice versa.At 408, according to the commands 348, the steering actuator module 344 applies a predetermined negative torque to the steering wheel 204 for a predetermined period of time to counteract the torque applied to the steering wheel 204 by the driver to maintain the steering wheel 204 at the predetermined steering wheel angle. Negative in this sense is expressed with respect to the driver torque, which is positive. The predetermined torque may be, for example, 0.2-1.0 Newton-meters (Nm) or another suitable magnitude. The predetermined period may be, for example, 0.1-1 seconds or another suitable predetermined period. For example, if the driver is to maintain the steering wheel 204 in a predetermined position that is zero in a clockwise direction with respect to the steering wheel angle, the steering actuator module 344 applies torque in a counterclockwise direction. If the driver is to maintain the steering wheel 204 in a predetermined position that is zero counterclockwise with respect to the steering wheel angle, the steering actuator module 344 applies torque in a clockwise direction.At 412, the magnitude assessment module 304 records the SW measurements 308 during application of the negative torque by the steering feel motor 224 and the torque (with respect to the negative torque applied by the steering feel motor 224) by the driver. This includes, for example, the steering wheel angle 142 and may include the grip force.FIG. 5 includes an example graph of steering wheel angle 504, torque 508, and grip force 512 versus time 516. A torque axis 520 is also illustrated. As illustrated, a predetermined torque (which in this example has a magnitude of about 0.5 Nm) is applied by the steering feel motor 224 for a predetermined period of time (in this example, about 0.08 seconds).At 416, when the predetermined amount of time has elapsed, the steering actuator module 344 stops outputting the predetermined torque by the steering feel motor 224, such as by disconnecting the steering feel motor 224 from the power supply. At 420, the severity assessment module 304 determines the driver's muscle parameters.The strength assessment module 304 determines the muscle parameters based on the steering wheel angle measured during a predetermined time period that includes the predetermined time period during which the steering feel motor 224 outputs the predetermined torque for the strength assessment. This predetermined period may start at or before the predetermined period during which the steering feel motor 224 outputs the predetermined torque for strength judgment. This predetermined period may end at or after the end of the predetermined period during which the steering feel motor 224 outputs the predetermined torque for strength judgment. The severity assessment module 304 may determine the driver's muscle parameters using either an equation or a look-up table that relates measured steering wheel angles to muscle parameters during the predetermined time period. In the example of a lookup table, the lookup table may be calibrated based on the predetermined torque τ. For example, the strength evaluation module 304 may determine the muscle parameters using the following equation: where J is a muscle spring value of the driver, the second derivative of the steering wheel angle, d is a muscle attenuation value of the driver, θea is the first derivative of the steering wheel angle, k is a muscle mass coefficient of the driver, θ is the steering wheel angle, and τ is the predetermined torque applied by the steering feel motor 224. The driver's muscle parameters in this example include J, d, and k. The strength assessment module 304 may determine the muscle parameters using, for example, least squares or in another suitable manner. In various implementations, the strength assessment module 304 may determine the muscle parameters using a neural network (NN), such as an artificial neural network (ANN). The strength assessment module 304 may determine the muscle parameters further based on the grip force, in various implementations.FIG. 6 is a flowchart illustrating an exemplary method of controlling the steering feel motor 224 based on the driver's muscle parameters determined based on the driver's severity judgment. Control begins at 604, where the severity assessment module 304 determines the driver's muscle parameters as discussed above.At 608, the severity evaluation module 304 may determine the driver's severity level based on the driver's muscle parameters. The severity assessment module 304 may set the severity level to one of a discrete number of severity levels based on the muscle parameters being in predetermined criteria for that particular severity level. For example, the severity assessment module 304 may set the severity level to a first severity level when the muscle parameters meet a first predetermined set of criteria. The severity assessment module 304 may set the severity level to a second severity level when the muscle parameters meet a second predetermined set of criteria. The severity assessment module 304 may set the severity level to a third severity level when the muscle parameters meet a third predetermined set of criteria. The severity assessment module 304 may set the severity level to a fourth severity level when the muscle parameters meet a fourth predetermined set of criteria. The severity assessment module 304 may set the severity level to a fifth severity level when the muscle parameters meet a fifth predetermined set of criteria. While the example of five strength levels is provided, the present application is also applicable to other numbers of strength levels. The strength assessment module 304 may set the strength level using, for example, an NN such as an ANN.At 612, the steering actuator module 344 determines steering parameters for the steering feel motor 224 based on the driver's strength level. The steering parameters may include, for example, a power assist gain 704 of the steering feel motor 224, a linearity gain 708 of the steering feel motor 224, a stiffness 712 of the steering feel motor 224, a steering wheel damping 716 of the steering feel motor 224, and a steering ratio 720 of the steering feel motor 224. However, the present application is also applicable to other steering parameters and other combinations of steering parameters.For example, the steering actuator module 344 may set the steering parameters to a first set of steering parameters when the magnitude level is set to the first magnitude level. The steering actuator module 344 may set the steering parameters to a second set of steering parameters when the strength level is set to the second strength level. The steering actuator module 344 may set the steering parameters to a third set of steering parameters when the magnitude level is set to the third magnitude level. The steering actuator module 344 may set the steering parameters to a fourth set of steering parameters when the magnitude level is set to the fourth magnitude level. The steering actuator module 344 may set the steering parameters to a fifth set of steering parameters when the strength level is set to the fifth strength level.At 616, the steering actuator module 344 controls the steering feel motor 224 based on the steering parameters and controls the steering actuator motor 240 based on the steering wheel angle 142.FIG. 7 includes an example table illustrating steering features and corresponding steering parameters. An X in the table indicates that the steering parameter affects this steering characteristic.In various implementations, the strength assessment module 304 may determine the steering characteristics for the driver based on the muscle parameters. The severity evaluation module 304 may determine the steering characteristics using, for example, an NN such as an ANN.In various implementations, the infotainment module 183 may generate a graphical illustration that illustrates the driver's steering characteristics. For example, infotainment module 183 may generate a spider diagram or other suitable graphical illustration of the driver's steering characteristics. The infotainment module 183 may visually output the graphical illustration on a display in the passenger compartment.FIG. 8 includes an example spider diagram for steering characteristics of steering effort 804, steering feedback 808, steering directivity and sensitivity 812, center-to-center trace 816, and linearity 820 for a reference driver and drivers 1-4.

Claims

A steering system for electro-mechanically steering a vehicle, comprising: a steering feel motor (224) configured to apply torque to a steering column (212) and a steering wheel (204); a steering actuator motor (240) configured to actuate one or more steering components and turn wheels (232) of the vehicle; and a steering assessment module configured to issue commands for a severity assessment of a driver of the vehicle; characterized by: an infotainment module (183) configured to issue a command to the driver to maintain the steering wheel at a first predetermined angle that is a clockwise or counterclockwise angle with respect to a second predetermined angle based on the commands for the severity assessment; and a steering actuator module (344) configured to control the steering feel motor (224) and output a predetermined torque to the steering column (212) and the steering wheel for a predetermined time period that overlaps with the command for the driver to maintain the steering wheel at the first predetermined angle, wherein the torque output by the steering actuator module (344) is clockwise when the first predetermined angle is a counterclockwise angle with respect to the second predetermined angle, and wherein the torque output by the steering actuator module (344) is counterclockwise when the first predetermined angle is a clockwise angle with respect to the second predetermined angle; wherein the steering assessment module is configured to determine muscle parameters of the driver based on steering wheel angle measurements taken during the predetermined time period, and the steering actuator module (344) is configured to control a torque output of the steering feel motor (224) during driving of the vehicle based on the muscle parameters of the driver.Steering system for electromechanical steering according to claim 1, characterized in that the muscle parameters comprise a muscle spring of the driver.Steering system for electromechanical steering according to Claim 1, characterized in that the muscle parameters comprise a driver attenuation coefficient.Steering system for electromechanical steering according to claim 1, characterised in that the muscle parameters comprise a driver mass coefficient.The electromechanical steering system of claim 1, characterized in that the strength assessment module is configured to determine the muscle parameters using either an equation or a look-up table relating a steering wheel angle to muscle parameters.The electromechanical steering system of claim 1, characterized in that the strength assessment module (304) is configured to determine the muscle parameters using the following equation: J θ%0020̈ + d θ%0020̇ + k θ = τ, wherein J is a muscle spring value of the driver, θ%0020̈ is a second derivative of the steering wheel angle, d is a muscle damping value of the driver, θ̇ is a first derivative of the steering wheel angle, k is a muscle mass coefficient of the driver, θ is the steering wheel angle, and τ is the predetermined torque.The electromechanical steering system of claim 6, characterized in that the strength assessment module (304) is configured to determine the muscle parameters using least squares.The electromechanical steering system of claim 1, characterized in that: the steering evaluation module is configured to determine a driver strength level based on the muscle parameters; and the steering actuator module (344) is configured to: determine steering parameters based on the strength level and control the torque output of the steering feel motor (224) during driving of the vehicle based on the steering parameters.The electromechanical steering system of claim 8, characterized in that the steering parameters include a power assist gain provided by the steering feel motor (224).The electromechanical steering system of claim 8, characterized in that the steering parameters include linearity gain provided by the steering feel motor (224).

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