Method for limiting steering intervention of driver assistance system

Abstract

The invention relates to a method for limiting steering intervention of a driver assistance system of a vehicle. According to the invention, in order to limit the steering intervention, a control variable (u) of the driver assistance system generated for the steering intervention is multiplied by a weighting factor (f (a, b, c)) which is determined on the basis of a detected manual steering intervention of the driver and on the basis of a predetermined steering intervention permitted by the driver.

Description

Technical Field

[0001] The invention relates to a method for limiting a steering intervention of a driver assistance system of a vehicle according to the preamble of claim 1 . Background Art

[0002] Such a method is known from DE 10 2008 033 688 A1. This publication discloses a method for operating a steering control device to control the lateral movement of a vehicle as a function of two target variables generated externally to the steering control device. The first target variable represents a steering angle or yaw rate target value and is subject to speed-related limitations. The second target variable represents a steering torque target value. The difference between the first target variable subject to speed-related limitations and the actual variable corresponding to the first target variable is determined as a control deviation, wherein this control deviation is converted into a regulating variable according to a preset control function. The regulating variable is limited by weighting, gradient limiting and value limiting according to externally generated limiting parameters. The limited regulating variable is added to the second regulating variable to form a regulating signal for controlling a steering regulator acting on a steering system of the vehicle.

[0003] Furthermore, DE 10 2018 200 388 A1 discloses a method for operating a vehicle with a driver assistance system that intervenes in the lateral dynamics of the vehicle. The method comprises the following steps:

[0004] - identifying a driver intervention in the driving behavior of the vehicle based on an intervention in an actuator triggered by a driver assistance system;

[0005] - interpreting the driver intervention as excessive control of the actuator intervention; and

[0006] - reducing the intervention of the actuators in a defined manner based on the interpretation of the driver's intervention, thereby feeding back the driving task to the driver under control in a defined manner.

[0007] DE 10 2018 200 327 A1 describes a method for setting the degree of assistance of a driver assistance system of a vehicle, which driver assistance system can autonomously intervene in vehicle units that influence driving dynamics. In this case, the driver intervention leads to excessive control of the intervention autonomously carried out by the driver assistance system if the control intensity of the driver intervention exceeds a settable control limit value. The control limit value is set as a function of the relationship between the driving state and the quality of the information on which the intervention of the driver assistance system is based.

[0008] DE 10 2014 226 781 A1 discloses a method for controlling a steering device of a vehicle, in which target values ​​for an automatic steering mode and a manual steering mode are determined and a weighted sum is performed to achieve a gradual transition between the automatic and manual steering modes. Summary of the invention

[0009] The object of the present invention is to provide a new method for limiting a steering intervention of a driver assistance system of a vehicle.

[0010] According to the invention, this object is achieved by a method having the features of claim 1 .

[0011] Advantageous embodiments of the invention are the subject matter of the dependent claims.

[0012] According to the present invention, in a method for limiting a steering intervention of a driver assistance system of a vehicle, in order to limit the steering intervention, a driver assistance system adjustment variable generated for the steering intervention is multiplied by a weighting factor, and the weighting factor is determined based on a detected manual steering intervention of the driver and based on a preset steering intervention that is allowed to the driver.

[0013] The lateral control of the vehicle consists in particular in the planning and control of the vehicle movement superimposed by means of the steering angle control in the steering system. In this case, the steering movement needs to be monitored and limited in the event of a fault in order to ensure the safety of the entire system. In other words, the driver must monitor the steering, in particular the semi-automatic driver assistance functions, which intervene in the driving mode of the vehicle at all times, and the steering intervention must be limited so that the driver can control it. This limitation can be implemented in the steering actuator or in the command / master control device.

[0014] The method allows for reliable and safe limiting of steering interventions. In this case, a particularly harmonious transition can be achieved when the driver intervenes, thereby optimizing the steering feel during the driver intervention. In addition, a particularly high permissible steering performance can be achieved while the driver remains in control of the vehicle.

[0015] According to a feasible technical solution of the method, the permissible steering intervention is preset according to the driving speed of the vehicle, which can further improve the reliability and safety of steering intervention limitation.

[0016] According to another feasible technical solution of the method, the manual steering intervention is based on

[0017] - Steering angular velocity and / or

[0018] - Steering angle and / or

[0019] - Manual torque applied to the vehicle's steering handle

[0020] This allows, on the one hand, a very reliable and easy-to-implement detection of a manual steering intervention and, on the other hand, ensures a high level of robustness in the monitoring by means of a time-dependent monitoring of at least one of these variables.

[0021] According to another possible technical solution of the method, the preset permissible steering intervention

[0022] - in the event of a detected manual steering intervention, according to the steering angle speed as the permissible steering angle speed and / or

[0023] - in the event of a detected manual steering intervention, according to the steering angle as the permissible steering angle and / or

[0024] - in the event of a detected manual steering intervention, according to the manual torque as the permitted manual torque

[0025] Make a preset.

[0026] According to another possible technical solution of the method, the weighting factor is formed by a plurality of single weighting factors, wherein one of the single weighting factors is a steering angle speed weighting factor, which is determined according to an allowed steering angle speed, and the allowed steering angle speed is preset according to the detected steering angle speed and the driving speed. In this way, the weighting factor can be determined in an easy-to-implement and reliable manner.

[0027] According to another feasible technical solution of the method, to determine the steering angular velocity weighting factor

[0028] - determining a deviation of the value of the detected steering angular velocity from the permitted steering angular velocity and normalizing it to the permitted steering angular velocity to form a normalized deviation of the detected steering angular velocity,

[0029] - determining a robust steering angle velocity deviation from the normalized deviation of the detected steering angle velocity, such that the normalized deviation of the detected steering angle velocity limits the steering intervention only if a driver assistance system that performs a steering intervention is activated and the measured driver intervention is below a predefined limit value,

[0030] - forming an error integral as the integral of the robust steering angle velocity deviation, and

[0031] - Depending on the value of the error integral, a steering angle velocity weighting factor is determined from the characteristic diagram.

[0032] This technical solution enables robust determination of the steering angle velocity weighting factor in a simple and reliable manner.

[0033] According to another possible technical solution of the method, the weighting factor is formed by a plurality of single weighting factors, one of which is a steering angle weighting factor, which is determined according to an allowed steering angle, which is preset according to the detected steering angle and the driving speed. This also makes it possible to determine the weighting factor in an easy-to-implement and reliable manner.

[0034] According to another feasible technical solution of the method, to determine the steering angle weighting factor

[0035] - determining a deviation of the value of the detected steering angle from the permitted steering angle and normalizing it to the permitted steering angle to form a normalized deviation of the detected steering angle,

[0036] - determining a robust steering angle deviation from the normalized deviation of the detected steering angle, such that the normalized deviation of the detected steering angle limits the steering intervention only if a driver assistance system that performs the steering intervention is activated and the measured driver intervention is below a predefined limit value,

[0037] - forming an error integral as the integral of the robust steering angle deviation, and

[0038] - Depending on the value of the error integral, a steering angle weighting factor is determined from the characteristic diagram.

[0039] This technical solution enables robust determination of the steering angle weighting factor in a simple and reliable manner.

[0040] According to another possible technical solution of the method, the weighting factor is formed by a plurality of single weighting factors, wherein one single weighting factor is a manual torque weighting factor, which is determined according to an allowed manual torque, and the allowed manual torque is preset according to the detected manual torque and the driving speed. In this way, the weighting factor can also be determined in an easy-to-implement and reliable manner.

[0041] According to another feasible technical solution of the method, to determine the manual torque weighting factor

[0042] - forming a reduced manual torque by subtracting a defined constant value from the permitted manual torque,

[0043] - comparing the detected manual torque with the reduced manual torque,

[0044] - if the value of the detected manual torque is less than or equal to the reduced manual torque, the manual torque weighting factor corresponds to the value 1,

[0045] - if the value of the detected manual torque is greater than the reduced manual torque, the manual torque weighting factor corresponds to the value 0, and

[0046] If the value of the detected manual torque lies between the permitted manual torque and the reduced manual torque, the manual torque weighting factor corresponds to a value between 0 and 1 determined by linear scaling.

[0047] This technical solution enables robust determination of the manual torque weighting factor in a simple and reliable manner. BRIEF DESCRIPTION OF THE DRAWINGS

[0048] Embodiments of the present invention are explained in more detail below with reference to the accompanying drawings.

[0049] in:

[0050] Figure 1 Schematic flow chart of a method for limiting a steering intervention of a driver assistance system,

[0051] Figure 2 is a schematic block diagram of a limiter for limiting a steering intervention of a driver assistance system,

[0052] Figure 3 A schematic diagram of a possible sequence for generating a single weighting factor for weighting the steering angle velocity,

[0053] Figure 4 A schematic diagram of a possible process for generating a single weighting factor for weighting the steering angle, and

[0054] Figure 5 A schematic diagram of a possible sequence for generating a single weighting factor for weighting the manual torque.

[0055] In all the figures, parts which correspond to one another are provided with the same reference numerals. DETAILED DESCRIPTION

[0056] Figure 1 The sequence of a possible exemplary embodiment of a method for limiting a steering intervention of a driver assistance system of a vehicle is shown.

[0057] The lateral control of the vehicle consists in particular in the planning and control of the vehicle movement superimposed by means of the steering angle control in the steering system. In this case, the steering movement needs to be monitored and limited in the event of a fault in order to ensure the safety of the entire system. This limitation can be implemented in the steering actuator or in the master / command control device.

[0058] For this limitation, firstly, in method step VS1 , a manual steering intervention is detected based on the detection of the steering angle velocity v and / or the steering angle α and / or the manual torque M applied to the steering handle of the vehicle.

[0059] In a second method step VS2 , the robustness of the detection is increased by time-dependent monitoring.

[0060] In the third method step VS3, in particular by limiting Figure 2 The steering intervention of the driver assistance system is limited by the manipulated variable u shown in detail in FIG.

[0061] Figure 2 A block diagram of a possible exemplary embodiment of a limiter 1 for limiting a steering intervention of a driver assistance system is shown.

[0062] The limiter 1 comprises four modules 1.1 to 1.4, wherein the first module 1.1 is a steering angle speed limiter, the second module 1.2 is a steering angle limiter, the third module 1.3 is a manual torque limiter, and the fourth module 1.4 is a total limiter.

[0063] Therein, the first module 1.1 monitors the steering angle velocity v and generates a steering angle velocity weighting factor a as a single / individual weighting factor.

[0064] The second module 1 . 2 monitors the steering angle α and generates a steering angle weighting factor b as a single weighting factor.

[0065] The third module 1.3 monitors the manual torque M and generates a manual torque weighting factor c as a single weighting factor.

[0066] In a fourth module 1.4, a weighting of all individual weighting factors is carried out and a weighting factor f(a, b, c) is generated as a function of the individual weighting factors.

[0067] Among them, the weighting factor f(a, b, c) can be determined according to

[0068] f(a,b,c) = Minimum function of minimum value (a,b,c)

[0069] according to

[0070] f(a,b,c) = Multiplication function of (a,b,c)

[0071] and / or according to

[0072] f(a,b,c) = Mean function of mean(a,b,c).

[0073] Then, by multiplying the control variable u (which is, for example, the required target steering rack force) by

[0074] u lim = f(a, b, c)*u weighting factor f(a, b, c) to limit the steering intervention, thereby obtaining the limited driver assistance system adjustment variable u lim .

[0075] That is, in order to limit the steering intervention, the driver assistance system control variable u generated for the steering intervention is multiplied by the weighting factor f(a, b, c). The weighting factor f(a, b, c) is determined based on the detected manual steering intervention of the vehicle driver and based on the preset steering intervention allowed by the driver by forming the weighting factor f(a, b, c) as a function of the aforementioned single weighting factor.

[0076] Figure 3 A possible process for generating a single weighting factor for weighting the steering angular velocity v, that is, generating a steering angular velocity weighting factor a, is shown. Figure 2 The first module is carried out as shown in 1.1.

[0077] In block B1, the vehicle speed v is Fzg and the input variables of the steering angular velocity v, which is taken as the vehicle speed v Fzg The permissible steering angle velocity ev is calculated from the characteristic curve family of functions.

[0078] The vehicle speed v is calculated from the table containing the reference points. Fzg The permissible steering angle velocity ev of the function, where the vehicle speed v in this table Fzg For example, the steering angle velocity v is mapped / plotted on the horizontal axis (x-axis) and the steering angle velocity v is mapped / plotted on the vertical axis (y-axis). The values ​​between the reference points are determined by any (e.g. linear) interpolation method. Fzg The reference point of the value is fixed in km / h, for example v Fzg =[0, 10, 20, 30, 50, 80, 100, 130, 180, 250]. The reference point of the permissible steering angle velocity ev is determined, for example, by driving tests and / or with the aid of simulations. The aim is to ensure the controllability requirements of the steering angle velocity for the functional safety of the driver.

[0079] In the second block B2, the deviation of the detected steering angular velocity v from the permissible steering angular velocity ev is determined and normalized to the permissible steering angular velocity ev. The result of the normalization is a normalized deviation Δv of the detected steering angular velocity v, hereinafter also referred to as normalized steering angular velocity deviation Δv.

[0080] In the third block B3, the normalized steering angular velocity deviation Δv is filtered, and a robust steering angular velocity deviation Δv is formed by filtering. r Wherein, the filtered or robust steering angular velocity deviation Δv r is formed in such a way that the normalized steering angular velocity deviation Δv limits the steering intervention only if a driver assistance system that carries out the steering intervention is activated and the driver does not intervene forcefully / excessively, in particular does not perform forceful / excessive counter-control, for example counter-steering to a preset extent at most against the steering intervention of the driver assistance system.

[0081] Robust steering angular velocity deviation Δv r The calculation method of is as follows:

[0082] Δv r =Δv*S*c

[0083] where Δv r Denotes the robust steering angular velocity deviation Δv r , Δv represents the normalized steering angular velocity deviation Δv, S represents a signal representing the activation state of the driver assistance system that implements the steering intervention, and has a value of 1 when the driver assistance system is activated, otherwise it is 0, and c is a driver intervention limiting factor, which can be a value between 0 and 1, and has a value of 0 when the driver intervenes too much, especially too much reverse control, that is, counter-steering to a degree exceeding a preset level against the steering intervention of the driver assistance system. The driver intervention limiting factor c refers in particular to the manual torque weighting factor c generated by the third module 1.3.

[0084] In the fourth block B4, a robust steering angular velocity deviation Δv is formed. r The integral of the error integral ∫Δv r , where the error integral ∫Δv r The lower bound of is specifically 0.

[0085] In the fifth box B5, according to the error integral ∫Δv r The steering angular velocity weighting factor a is determined from the characteristic curve. For example, the steering angular velocity weighting factor a is calculated with the aid of a table containing reference points, where the error integral ∫Δv r The value of is plotted on the horizontal axis (x-axis), and the steering angular velocity weighting factor a is plotted on the vertical axis (y-axis). The values ​​between the reference points are determined by an arbitrary (e.g. linear) interpolation method. Error integral ∫Δv r The reference point of the value of is, for example, fixedly preset, such as ∫Δv r =[0,1,2,5,10,50]. The reference point of the steering angular velocity weighting factor a is determined, for example, by driving tests and / or with the aid of simulations, so that, for example, a=[1,1,1,1,0,0].

[0086] Figure 4 A possible process for generating a single weighting factor for weighting the steering angle α, that is, generating the steering angle weighting factor b, is shown. Figure 2 The second module is shown in 1.2.

[0087] Among them, in box B6, according to the form of driving speed v Fzg and the input variables of the steering angle α, which are represented by the vehicle speed v Fzg The permissible steering angle eα is calculated from the characteristic curve group of functions.

[0088] The vehicle speed v is calculated from the table containing the reference points. FzgThe permissible steering angle eα as a function of the vehicle speed v in this table Fzg For example, the steering angle eα is plotted on the horizontal axis (x-axis) and the permissible steering angle eα is plotted on the vertical axis (y-axis). The values ​​between the reference points are determined by any (e.g. linear) interpolation method. Fzg The reference point of the value is fixed in km / h, for example v Fzg =[0, 10, 20, 30, 50, 80, 100, 130, 180, 250]. The reference point of the permissible steering angle eα is determined, for example, by driving tests and / or with the aid of simulations. The aim is to ensure the controllability requirements of the steering angle α for the functional safety of the driver.

[0089] In the second block B7, the deviation of the detected steering angle α from the allowed steering angle eα is determined and normalized to the allowed steering angle eα. The normalization result is a normalized deviation Δα of the detected steering angle α, hereinafter also referred to as normalized steering angle deviation Δα.

[0090] In the third block B8, the normalized steering angle deviation Δα is filtered, and a robust steering angle deviation Δα is formed by filtering. r Where, the filtered or robust steering angle deviation Δα r is formed in such a way that the normalized steering angle deviation Δα limits the steering intervention only if the driver assistance system that carries out the steering intervention is activated by the signal S and the driver does not intervene too much, in particular does not perform too much counter-control, for example counter-steering to a maximum of a predefined extent against the steering intervention of the driver assistance system.

[0091] Robust steering angle deviation Δα r The calculation method of is as follows:

[0092] Δα r =Δα*S*c

[0093] where Δα r Denotes the robust steering angle deviation Δα r , Δα represents the normalized steering angle deviation Δα, S represents the above-mentioned signal representing the activation state of the driver assistance system, and c represents the above-mentioned driver intervention limiting factor, in particular the manual torque weighting factor c generated by the third module 1.3.

[0094] In the fourth block B9, a robust steering angle deviation Δα is formed. r The integral of the error integral ∫Δα r , where the error integral ∫Δα r The lower bound of is specifically 0.

[0095] In the fifth block B10, according to the error integral ∫Δα r The steering angle weighting factor b is determined from the characteristic curve. For example, the steering angle weighting factor b is calculated with the aid of a table containing reference points, where the error integral ∫Δα r The value of is plotted on the horizontal axis (x-axis) and the steering angle weighting factor b is plotted on the vertical axis (y-axis). The values ​​between the reference points are determined by any (e.g. linear) interpolation method. Error integral ∫Δα r The reference point of the value of is, for example, fixedly preset, such as ∫Δα r =[0,1,2,5,10,50]. The reference point of the steering angle weighting factor b is determined, for example, by driving tests and / or with the aid of simulations, so that, for example, b=[1,1,1,1,0,0].

[0096] Figure 5 A possible process for generating a single weighting factor for weighting the manual torque M, that is, the generated manual torque weighting factor c, is shown. This process is, for example, Figure 2 The third module is shown in 1.3.

[0097] To determine the manual torque weighting factor c, firstly, in a first block B11 it is determined whether the detected manual torque M and the manipulated variable u of the driver assistance system are steered in the same direction (+) or in the opposite direction (-).

[0098] If the detected manual torque M is in the same direction +, the manual torque weighting factor c is set to a value of 1 in the second block B12.

[0099] If the detected manual torque M is in the opposite direction -, then in the third box B13 the input variable driving speed v Fzg As the driving speed v Fzg The permissible manual torque eM is calculated from the characteristic curve family of functions.

[0100] The vehicle speed v is calculated from the table containing the reference points. Fzg The value of the permissible manual torque eM as a function of the vehicle speed v in this table Fzg For example, the torque eM is plotted on the horizontal axis (x-axis) and the permissible manual torque eM is plotted on the vertical axis (y-axis). The values ​​between the reference points are determined by any (e.g. linear) interpolation method. Vehicle speed v Fzg The reference point of the value is fixed in km / h, for example v Fzg =[0, 10, 20, 30, 50, 80, 100, 130, 180, 250]. The reference point of the permissible manual torque eM is determined, for example, by driving tests and / or with the aid of simulations. The goal is to ensure the controllability requirements of the manual torque M for the functional safety of the driver.

[0101] In a fourth block B14 , the reduced manual torque rM is formed by subtracting a defined constant value (eg 0.5) from the permitted manual torque eM.

[0102] Subsequently, the detected manual torque M is compared with the reduced manual torque rM, wherein the manual torque weighting factor c corresponds to a value of 1 if the value of the detected manual torque M is less than or equal to the reduced manual torque rM (as shown in detail A1 ).

[0103] If the detected manual torque M is greater than or equal to the allowed manual torque eM (as shown in the partial A2 ), the manual torque weighting factor c corresponds to a value of 0.

[0104] If the value of the detected manual torque M is between the allowed manual torque eM and the reduced manual torque rM (as shown in detail A3 ), the manual torque weighting factor c corresponds to a value between 0 and 1 determined by linear scaling.

Claims

1. A method for limiting a steering intervention of a driver assistance system of a vehicle, wherein, in order to limit the steering intervention, a manipulated variable (u) of the driver assistance system generated for the steering intervention is multiplied by a weighting factor (f(a, b, c)), It is characterized in that The weighting factor (f(a, b, c)) is determined based on a detected manual steering intervention of the driver and based on a predefined permissible steering intervention of the driver.

2. The method according to claim 1, It is characterized in that According to the vehicle's driving speed (v Fzg ) to preset the permitted steering intervention.

3. The method according to claim 1 or 2, It is characterized in that The manual steering intervention is based on - Steering angular velocity (v) and / or - steering angle (α) and / or - Manual torque applied to the steering handle of the vehicle (M) Conduct testing.

4. The method according to claim 3, It is characterized in that The predefined permissible steering intervention - in the event of detection of the manual steering intervention, according to the steering angle speed (v) as the permitted steering angle speed (ev) and / or - in the event of detection of the manual steering intervention, according to the steering angle (α) as the permissible steering angle (eα) and / or - in the event of detection of the manual steering intervention according to the manual torque (M) as the permitted manual torque (eM) Make a preset.

5. The method according to claim 4, It is characterized in that The weighting factor (f(a, b, c)) is formed by a plurality of single weighting factors, wherein one of the single weighting factors is a steering angle velocity weighting factor (a), which is determined according to an allowable steering angle velocity (ev), wherein the allowable steering angle velocity is determined according to the detected steering angle velocity (v) and the vehicle speed (v Fzg ) to preset.

6. The method according to claim 5, It is characterized in that To determine the steering angular velocity weighting factor (a) - determining a deviation of the value of the detected steering angular velocity (v) from said permissible steering angular velocity (ev) and normalizing it to said permissible steering angular velocity (ev) to form a normalized deviation (Δv) of the detected steering angular velocity (v), - Determine the robust steering angular velocity deviation (Δv) from the normalized deviation (Δv) of the detected steering angular velocity (v) r ), so that the normalized deviation (Δv) of the detected steering angular velocity (v) limits the steering intervention only if the driver assistance system implementing the steering intervention is activated and the measured driver intervention is below a predefined limit value, - formed as the robust steering angular velocity deviation (Δv r ) of the integral of the error integral (∫Δv r ),as well as - According to the error integral (∫Δv r ) value, the steering angular velocity weighting factor (a) is determined by the characteristic curve family.

7. The method according to any one of claims 4 to 6, It is characterized in that The weighting factor (f(a, b, c)) is formed by a plurality of single weighting factors, wherein one single weighting factor is a steering angle weighting factor (b), which is determined according to an allowable steering angle (eα), wherein the allowable steering angle is determined according to the detected steering angle (α) and the vehicle speed (v Fzg ) to preset.

8. The method according to claim 7, It is characterized in that To determine the steering angle weighting factor (b) - determining a deviation of the value of the detected steering angle (α) from said permissible steering angle (eα) and normalizing it to said permissible steering angle (eα) to form a normalized deviation (Δα) of the detected steering angle (α), - Determine the robust steering angle deviation (Δα) from the normalized deviation (Δα) of the detected steering angle (α) r ), so that the normalized deviation (Δα) of the detected steering angle (α) limits the steering intervention only if the driver assistance system that implements the steering intervention is activated and the measured driver intervention is below a predefined limit value, - formed as the robust steering angle deviation (Δα r ) of the integral error integral (∫Δα r ),as well as - According to the error integral (∫Δα r ) value, the steering angle weighting factor (b) is determined by the characteristic curve family.

9. The method according to any one of claims 4 to 8, It is characterized in that The weighting factor is formed by a plurality of single weighting factors, wherein one of the single weighting factors is a manual torque weighting factor (c), which is determined according to an allowable manual torque (eM), wherein the allowable manual torque is determined according to the detected manual torque (M) and the vehicle speed (v Fzg ) to preset.

10. The method according to claim 9, It is characterized in that To determine the manual torque weighting factor (c) - forming a reduced manual torque (rM) by subtracting a defined constant value from said permitted manual torque (eM), - comparing the detected manual torque (M) with said reduced manual torque (rM), - if the value of the detected manual torque (M) is less than or equal to the reduced manual torque (rM), the manual torque weighting factor (c) corresponds to the value 1, - if the value of the detected manual torque (M) is greater than or equal to the allowed manual torque (eM), the manual torque weighting factor (c) corresponds to the value 0, and If the value of the detected manual torque (M) lies between the allowed manual torque (eM) and the reduced manual torque (rM), the manual torque weighting factor (c) corresponds to a value between 0 and 1 determined by linear scaling.

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