DE112019001018T5 - Vehicle steering device - Google Patents

Abstract

[Object] To provide a vehicle steering apparatus in which, without being influenced by the condition of a road surface and regardless of changes in mechanical characteristics of the steering control system due to aging, a steering torque equivalent to a steering angle can be easily realized. [Solution] Vehicle performing auxiliary control of the steering control system -Steering device comprises a target control torque generating target control torque generation component, a conversion component converting the target control torque into a target rotation angle and a rotation angle control component that calculates a motor current command value such that the rotation angle follows the target rotation angle, the Target control torque generation component comprises a SAT data corrector that calculates a first torque signal based on a self-aligning torque value and outputs the first torque signal as a target control torque, and the SAT data corrector is equipped with a SAT estimator that estimates the self-aligning torque value based on the control torque, the angle information and the motor current command value, and a filter component that filters the first torque signal by filtering the self-aligning torque value, and the motor is drive-controlled based on the motor current command value .

Description

Technical area

The present invention relates to a powerful vehicle steering device in which a desired control torque is realized based on the twist angle of a torsion bar without being influenced by the condition of a road surface and regardless of changes in mechanical characteristics due to aging.

Background technology

An electric power steering device (EPS), which is a type of vehicle steering device, gives the vehicle control system by the rotating force of a motor an assisting force (steering assist force), the driving force of the motor being generated by an electric power supplied from an inverter Power is controlled, through a transmission structure including a reduction gear, is given to a steering shaft or a crankshaft as an auxiliary power. In this conventional electric power steering device (EPS), feedback control of the motor current takes place in order to precisely generate the auxiliary power. In the feedback control, a motor application voltage is regulated in such a way that the difference between a steering assistance command value (current command value) and a motor current detection value is reduced, the regulation of the motor application voltage generally by regulating the keying of the PWM (pulse width modulation) control he follows.

To explain the in 1 The general structure of an electric power steering apparatus shown is a steering column shaft (steering shaft, steering wheel shaft) 2 of a steering wheel 1 via a reduction gear 3 , Cardan joints 4a and 4b , a rack and pinion mechanism 5 and tie rods 6a , 6b , and also about hub units 7a , 7b with steered vehicle wheels 8L , 8R connected. Furthermore, on the steering column shaft having a torsion bar 2 a a control moment Ts of the steering wheel 1 detecting torque sensor 10 and a steering angle sensor detecting a steering angle θh 14th provided, and one the steering force of the steering wheel 1 supporting engine 20th is about the reduction gear 3 with the steering column shaft 2 connected. Into a control unit (ECU) controlling the electric power steering device 30th is powered by a battery 13 electrical power supplied, and via an ignition key 11 an ignition key signal is input. The control unit 30th performs based on the by the torque sensor 10 detected control torque Ts and that by a vehicle speed sensor 12 detected vehicle speed Vs calculates the current command value for the assist (power steering) command, and controls the current supplied to the EPS motor by a voltage control command value Vref compensated by the current command value 20th is fed.

The control unit 30th is on a CAN (Controller Area Network) 40 connected, through which various vehicle data are exchanged, including the vehicle speed Vs from the CAN 40 can be received. The control unit 30th is also apart from the CAN 40 also to a non-CAN that exchanges communication, analog / digital signals, radio, etc. 41 connectable.

The control unit 30th consists mainly of a CPU (including an MCU, MPU, etc.), with general functions performed in the CPU by programs in 2 are shown.

To explain the functions and mode of operation of the control unit 30th based on 2 , this will be done by the torque sensor 10 detected control torque Ts and that by the vehicle speed sensor 12 detected vehicle speed Vs (or the one from CAN 40 ) into a current command value calculation component 31 entered. The current command value calculation component 31 calculated by means of an auxiliary map, etc. based on the entered control torque Ts and the vehicle speed Vs a current command value Iref1 , which is a control setpoint of the current supplied to the motor 20th is fed. The current command value Iref1 is via an adder component 32A into a current limiting component 33 is input, a current command value Irefm limited to a maximum current is put into a subtracting component 32B entered, a deviation I from the fed-back motor current value Im (= Irefm - Im) is calculated, and this deviation I into one PI (Proportional-integral) controller 35 entered to improve the characteristics of the control operation. A voltage control command value Vref with one by the PI regulator 35 improved characteristic is in a PWM control 36 entered, and the engine 20th is via an inverter 37 PWM-driven as a drive component. The current value Im of the motor 20th is by a motor current detector 38 detected and with the subtracting component 32B fed back.

In the adding component 32A becomes a compensation signal CM from a compensation signal generation component 34 added, and by adding the compensation signal CM a compensation of the characteristics of the control system performed, whereby the Convergence and inertia characteristics can be improved. At the compensation signal generation component 34 become a self-aligning torque (SAT) 343 and an indolence 342 through an adder 344 added, a convergence also becomes the result of the addition 341 through an adder 345 added, and the addition result of the adder 345 gives the compensation signal CM .

In this way, the control torque added in the auxiliary control of a conventional electric power steering apparatus by a manual input of the driver is detected as a twisting torque of a torsion bar by a torque sensor, and the motor current is mainly controlled as the auxiliary current corresponding to this torque. When controlled by this method, however, it happens that a different control torque results due to a different state of the road surface (e.g. an incline) due to the steering angle. The control torque can also be influenced by fluctuations in the engine output characteristics due to use with the passage of time.

To solve this problem, e.g. B. the patent No. JP Patent No. 5208894 B2 (Patent Document 1) has proposed an electric power steering apparatus. In the electric power steering apparatus of Patent Document 1, an appropriate control torque based on tactile characteristics of the driver is supplied so that the target value of the control torque is based on the ratio (control reaction force map) between the steering angle and the control torque based on the ratio of the steering angle or the control torque is set to the amount of feedback.

Prior art documents

Patent documents

Patent Document 1: JP Patent No. 5208894 B2

Summary of the invention

Problem to be solved by the invention

In the electric power steering apparatus of Patent Document 1, since a control reaction force map needs to be determined in advance and control is performed based on the deviation between the target value of the control torque and the detected control torque, it is feared that the control torque will remain influenced.

The present invention has been made in view of the foregoing problems and aims to provide a vehicle steering apparatus in which a control torque equivalent to a steering angle, etc. can be easily realized without being influenced by the condition of a road surface and regardless of changes in mechanical characteristics of the steering control system due to aging.

Means for solving the task

The present invention relates to a vehicle steering device which comprises at least one torsion bar having an arbitrary spring constant and a sensor which detects the twist angle of the torsion bar, and executes auxiliary control of the steering control system through the drive control of the motor, and the object of the present invention is achieved in that a target control torque generating component that generates a target control torque, a conversion component that converts the target control torque into a target rotation angle, and a rotation angle control component that calculates a motor current command value such that the rotation angle follows the target rotation angle, the Target control torque generation component is equipped with a SAT data corrector, which calculates a first torque signal based on a self-aligning torque value and outputs the first torque signal as a target control torque, and the SAT data cor A rectifier is provided with a SAT estimator that estimates the self-aligning torque value based on the control torque, the angle information, and the motor current command value, and a filter component that calculates the first torque signal by filtering the self-aligning torque value, and the motor is drive-controlled based on the motor current command value .

The object of the present invention can be achieved more effectively if the filter component consists of one or a plurality of filters connected in parallel, the SAT data correction element is further equipped with a control torque sensitivity amplification element which multiplies the first torque signal by a control torque sensitivity amplification, the control torque sensitivity amplification is set to be larger at the center, the SAT data corrector is further provided with a vehicle speed sensitivity gain that multiplies the first torque signal by a vehicle speed sensitivity gain, the vehicle speed sensitivity gain is set to be larger at a high speed is, the SAT data corrector is further provided with a steering angle sensitivity gain member that the first torque signal with a steering angle sensitivity gain multiplied, the SAT data corrector is further equipped with a restriction component that limits the first torque signal by an upper and lower limit value, the target control torque generation component with a basic map element that uses a basic map, the steering angle and based on the vehicle speed second torque signal is determined, a damping calculation element which determines a third torque signal by means of a vehicle speed-sensitive damping map based on angular velocity data, and furthermore a hysteresis correction element is equipped which carries out a hysteresis correction by means of the control state and the steering angle and determines a fourth torque signal, with at least one signal from the second torque signal, the third torque signal and the fourth torque signal and by the first torque signal, the target control torque is calculated, the characteristic of the basic Map and the hysteresis correction element is vehicle speed sensitive, or the target control torque generation component is further equipped with a phase compensation element upstream or downstream of the basic map element, and the second torque via the basic map element and the phase compensation element through the steering angle and the vehicle speed is determined.

Effects of the invention

The vehicle steering device of the present invention controls a target angle of rotation that is determined based on a target control torque generated by a target control torque generating component, the angle of rotation acting following the target angle of rotation and realizing a desired control torque , and a suitable control torque based on the sensory perception of the control by the driver can be supplied.

In addition, by using a self-aligning torque (SAT) value to generate the target control torque, road surface information can be appropriately transmitted to the driver as a control sensation while driving.

Figure list

• [ 1 ] 1 Fig. 13 is a structural diagram showing an outline of an electric power steering apparatus.
• [ 2 ] 2 Fig. 13 is a block diagram showing a structural example of the interior of the control unit (ECU) of an electric power steering apparatus.
• [ 3 ] 3 Fig. 13 is a construction diagram showing an installation example of the EPS control system and various sensors.
• [ 4th ] 4th Fig. 13 is a block diagram showing a structural example of the present invention (first embodiment).
• [ 5 ] 5 Fig. 13 is a block diagram showing a structural example of a target control torque generation component (first embodiment).
• [ 6th ] 6th Fig. 13 is a diagram showing an example of characteristics of a basic map.
• [ 7th ] 7th Fig. 13 is a diagram showing an example of characteristics of a damping gain map.
• [ 8th ] 8th Fig. 13 is a diagram showing an example of characteristics of a hysteresis corrector.
• [ 9 ] 9 Fig. 13 is a block diagram showing a structural example of a SAT data corrector (first embodiment).
• [ 10 ] 10 Fig. 13 is a pictorial view showing the state of torque developed in time from the road surface to the steering wheel.
• [ 11 ] 11 Fig. 13 is a diagram showing an example of the characteristic of control torque sensitivity gain.
• [ 12 ] 12 Fig. 13 is a diagram showing an example of the vehicle speed sensitivity gain characteristic.
• [ 13 ] 13 Fig. 13 is a diagram showing an example of the characteristic of steering angle sensitivity gain.
• [ 14th ] 14th Fig. 13 is a diagram showing a setting example of the upper and lower limit values of a restriction component.
• [ 15th ] 15th Figure 13 is a block diagram showing a structural example of a twist angle control component.
• [ 16 ] 16 Fig. 13 is a flow chart showing an operational example of the present invention (first embodiment).
• [ 17th ] 17th Fig. 13 is a flowchart showing an operation example of the target control torque generation component (first embodiment).
• [ 18th ] 18th Fig. 13 is a flow chart showing an operational example of the twist angle control component.
• [ 19th ] 19th Fig. 13 is a graph showing, in a simulation showing the effects of the SAT data corrector, the change in SAT values and the control torque without a SAT data corrector.
• [ 20th ] 20th Fig. 13 is a graph showing, in a simulation showing the effects of the SAT data corrector, the variation of the SAT values, torque signal and control torque with a SAT data corrector.
• [ 21st ] 21st Fig. 13 is a block diagram showing a structural example of a filter component (second embodiment).
• [ 22nd ] 22nd Fig. 13 is a block diagram showing a structural example of a target control torque generation component (third embodiment).
• [ 23 ] 23 Fig. 13 is a block diagram showing a structural example of the present invention (fourth embodiment).
• [ 24 ] 24 Fig. 13 is a block diagram showing an insertion example of a phase compensator.
• [ 25th ] 25th Fig. 13 is a structural diagram showing an outline of an SBW system.
• [ 26th ] 26th Fig. 13 is a block diagram showing a structural example of the present invention (fifth embodiment).
• [ 27 ] 27 Fig. 13 is a block diagram showing a structural example of a target turning angle generating component.
• [ 28 ] 28 Fig. 13 is a block diagram showing a structural example of a turning angle control component.
• [ 29 ] 29 Fig. 13 is a flow chart showing an operational example of the present invention (fifth embodiment).

Embodiments of the invention

The present invention is a vehicle steering apparatus for realizing an equivalent steering torque to a steering angle without being influenced by the state of the road surface, wherein a desired steering torque is realized by a control following the steering angle value.

In the following, embodiments of the present invention are explained with reference to the figures.

$$-Kt\cdot \Delta \theta =Tt$$

Das Torsionsstab-Drehmoment Tt kann z. B. mittels eines in der Veröffentlichung Nr. JP 2008 - 216172 A offenbarten Drehmomentsensors detektiert werden. In der vorliegenden Ausführungsform wird das Torsionsstab-Drehmoment Tt auch als Steuermoment Ts behandelt.First, a setting example of the respective sensors that detect data related to an electric power steering apparatus as a vehicle steering apparatus according to the present invention will be explained. 3 Fig. 13 is a diagram showing an installation example of the EPS control system and various sensors, with the steering column shaft 2 a torsion bar 2A includes. On the steered vehicle wheels 8L , 8R A road surface counter force Rr and road surface data µ are applied. On the steering wheel side of the torsion bar 2A in the center of the steering column shaft 2 an upper angle sensor is provided on the side of the steered vehicle wheels of the torsion bar 2A in the center of the steering column shaft 2 a lower angle sensor is provided, the upper angle sensor indicating a steering wheel angle θ ₁ detected, and the lower angle sensor a steering column angle θ ₂ detected. The steering angle θh is by one above the steering column shaft 2 provided steering angle sensor detected, and based on the deviation between the steering wheel angle θ ₁ and the steering column angle θ ₂ For example, a twist angle Δθ of the torsion bar and a torsion bar torque Tt can be determined by the following equation 1 and equation 2. Here, Kt is the spring constant of the torsion bar 2A . $${\theta }_2-{\mathrm{<figure-callout\; id="1"\; label="\theta "\; filenames="DE112019001018T5\_0017.png,DE112019001018T5\_0025.png"\; state="\{\{state\}\}">\theta </figure-callout>}}_1=\Delta \theta$$

$$-Kt\cdot \Delta \theta =Tt$$

The torsion bar torque Tt can e.g. B. by means of one in Publication No. JP 2008 - 216172 A disclosed torque sensor are detected. In the present embodiment, the torsion bar torque is Tt also as a control moment Ts treated.

Next, a structural example of the present invention will be explained.

4th Fig. 13 is a block diagram showing a structural example of the present invention (first embodiment) in which steering wheel control of a driver is performed by a motor inside an EPS control system / vehicle system 100 is auxiliary controlled. Into a target control torque generation component which outputs the target control torque Tref 200 is apart from the steering angle θh and the vehicle speed Vs , the control moment Ts , a motor angle θm as angle information, one of a twist angle control component 300 output motor current command value Imc and one from a right-turn / left-turn judgment component 400 output control state STs of a right turn or left turn input. The target control torque Tref is used in a conversion component 500 converted into a target twist angle Δθref, and the target twist angle Δθref is converted together with the twist angle Δθ des Torsion bars 2A and a motor angular velocity ωm into the twist angle control component 300 entered. The twist angle control component 300 calculates the motor current command value Imc such that the twist angle Δθ becomes the target twist angle Δθref, and the motor of the EPS is driven by the motor current command value Imc.

The right turn / left turn assessment component 400 judges whether the control is a right-hand turn or a left-hand turn based on the motor angular velocity ωm, and outputs the judgment result as the control state STs out. This means that if the motor angular velocity ωm is positive, a “right turn” is assessed, and if the value is negative, a “left turn” is assessed. Instead of the motor angular speed ωm, it is also possible to calculate the speed of the steering angle θh , the steering wheel angle θ ₁ or the steering column angle θ ₂ and the calculated angular velocity used.

5 Fig. 13 shows a structural example of the target control torque generation component 200 , wherein the target control torque generation component 200 a basic map element 210 , a differentiator 220 , an attenuation amplifier 230 , a hysteresis correction element 240 , a SAT data corrector 250 , a multiplier 260 and adder 261 , 262 and 263 includes, the steering angle θh into the basic map element 210 , the differentiator 220 , the hysteresis correction element 240 and the SAT data corrector 250 is inputted by the right-hand / left-hand judging component 400 output control status STs into the hysteresis correction element 240 is entered, the control torque Ts , the motor angle θm and the motor current command value Imc into the SAT data corrector 250 entered, and the vehicle speed Vs into the basic map element 210 , the attenuation gain link 230 and the SAT data corrector 250 is entered.

The basic map element 210 has a basic map and inputs in by means of the map 6th shown, the vehicle speed Vs parameterizing torque signal (second torque signal) Tref_a out. That is, the torque signal Tref_a increases with the increasing size of the steering angle θh (Absolute value) | θh | and also increases with increasing vehicle speed Vs . A marker link 211 gives a mark (+1 or -1) of the steering angle θh to a multiplier 212 out. Based on the size of the steering angle θh the size of the torque signal is determined by means of the map Tref_a determined this with the marking of the steering angle θh multiplied, and the torque signal Tref_a calculated. In 6th consists of the basic map element 210 from which the quantity | θh | the steering angle θh referring map, a marker and a multiplier, but it is also a structure as the positive / negative steering angle θh A corresponding map is possible, in which case the state of the change for a positive and a negative steering angle θh can be changed. Furthermore, the in 6th The basic map shown may or may not be sensitive to the vehicle speed.

The differentiator 220 differentiates the steering angle θh and calculates the steering angular speed ωh as angular speed information, and the angular speed information ωh is input to the multiplier 260 entered.

The attenuation gain link 230 gives a damping gain D _G off that with the steering angular speed ωh is multiplied. The ones in the multiplier 260 with the damping gain D _G multiplied steering angle speed ωh is used as a torque signal (third torque signal) Tref_b into the adder 262 entered. The damping gain D _G is by means of a vehicle speed-sensitive damping gain map, which the damping gain element 230 has, according to the vehicle speed Vs determined. The damping gain map has z. B., as in 7th shown, one with increasing vehicle speed Vs gradually increasing characteristic. The damping gain map can also correspond to the steering angle θh be changeable. The attenuation gain link 230 and the adder 260 form a damping calculation component.

Bei einer Umstellung von einer Rechtseinschlag-Steuerung zu einer Linkseinschlag-Steuerung oder von einer Linkseinschlag-Steuerung zu einer Rechtseinschlag-Steuerung wird basierend auf dem Wert der Endkoordinaten (x1, y1) „b“ in Gleichung 3 nach der Umstellung durch die folgende Gleichung 4 substituiert. Dadurch wird die Kontinuität vor und nach der Umstellung bewahrt. $$\begin{array}{l}\begin{array}{cc}\begin{array}{l}\text{Beim Rechts-}\\ \text{einschlag }\end{array}& \text{b}=x_1+\frac{1}{c}{\text{log}}_a\left(1-\frac{y_1}{A_{hys}}\right)\end{array}\\ \begin{array}{cc}\begin{array}{l}\text{Beim Links-}\\ \text{einschlag }\end{array}& \text{b'}=x_1+\frac{1}{c}{\text{log}}_a\left(1+\frac{y_1}{A_{hys}}\right)\end{array}\end{array}$$

Gleichung 4 kann durch Substitution von x in Gleichung 3 durch x1 und von y_R und y_L durch y1 abgeleitet werden.The hysteresis correction element 240 calculated based on the steering angle θh and the control status STs a torque signal (fourth torque signal) Tref_c by means of the following equation 3. In equation 3, x = θh, y = Tref_c, where a> 1, c> 0, and A _{hys is} the hysteresis _margin . $$\begin{array}{l}{\text{Right hand turn y}}_{\text{R.}}={\text{A.}}_{\text{hys}}\left\{1-{\text{a}}^{\text{c}(\text{xb}}\right\}\\ {\text{When turning to the left y}}_{\text{L.}}={\text{A.}}_{\text{hys}}\left\{1-{\text{a}}^{\text{c}(\text{xb '}}\right\}\end{array}$$

When changing over from right-hand turn control to left-hand turn control or from left-hand turn control to right-hand turn control, based on the value of the end coordinates (x1, y1) “b” in equation 3 after the changeover by the following equation 4 substituted. This maintains continuity before and after the changeover. $$\begin{array}{l}\begin{array}{cc}\begin{array}{l}\text{At the legal}\\ \text{a hit}\end{array}& \text{b}=x_1+\frac{1}{c}{\text{log}}_a\left(1-\frac{{\mathrm{<figure-callout\; id="1"\; label="y"\; filenames="DE112019001018T5\_0017.png,DE112019001018T5\_0025.png"\; state="\{\{state\}\}">y</figure-callout>}}_1}{{\mathrm{A.}}_{Hys}}\right)\end{array}\\ \begin{array}{cc}\begin{array}{l}\text{When left}\\ \text{a hit}\end{array}& \text{b '}=x_1+\frac{1}{c}{\text{log}}_a\left(1+\frac{{\mathrm{<figure-callout\; id="1"\; label="y"\; filenames="DE112019001018T5\_0017.png,DE112019001018T5\_0025.png"\; state="\{\{state\}\}">y</figure-callout>}}_1}{{\mathrm{A.}}_{Hys}}\right)\end{array}\end{array}$$

Equation 4 can be derived by substituting x1 for x in Equation 3 and y1 for y _R and y _L.

$$\begin{array}{l}\begin{array}{cc}\begin{array}{l}\text{Beim Rechts-}\\ \text{einschlag }\end{array}& \text{b}=x_1+\frac{1}{c}{\text{log}}_e\left(1-\frac{y_1}{A_{hys}}\right)\end{array}\\ \begin{array}{cc}\begin{array}{l}\text{Beim Links-}\\ \text{einschlag }\end{array}& \text{b'}=x_1-\frac{1}{c}{\text{log}}_e\left(1+\frac{y_1}{A_{hys}}\right)\end{array}\end{array}$$

In Gleichung 5 und 6 ist A_hys = 1 [Nm], c = 0,3 eingestellt, und ein Beispiel einer graphischen Darstellung des hysteresekorrigierten Drehmomentsignals Tref_c bei einer Steuerung von +50 [deg] , -50 [deg] beginnend von 0 [deg] ist in 8 gezeigt. Das heißt, das Drehmomentsignal Tref_c von dem Hysteresekorrekturglied 240 weist eine Hysteresecharakteristik wie bei Ursprung von 0 → L1 (dünne Linie) → L2 (gestrichelte Linie) → L3 (dicke Linie) auf.Any whole number greater than 1 can be used as “a”, where z. For example, when using the Napier number “e” from equation 3 and equation 4, the following equations 5 and 6 result. $$\begin{array}{l}\begin{array}{cc}\begin{array}{l}\text{At the legal}\\ \text{a hit}\end{array}& y_{\mathrm{R.}}={\mathrm{A.}}_{Hys}\left[1-\text{exp}\left\{-c\left(x-b\right)\right\}\right]\end{array}\\ \begin{array}{cc}\begin{array}{l}\text{When left}\\ \text{a hit}\end{array}& y_{\mathrm{L.}}=-{\mathrm{A.}}_{Hys}\left[1-\text{exp}\left\{c\left(x-b\text{'}\right)\right\}\right]\end{array}\end{array}$$

$$\begin{array}{l}\begin{array}{cc}\begin{array}{l}\text{At the legal}\\ \text{a hit}\end{array}& \text{b}=x_1+\frac{1}{c}{\text{log}}_e\left(1-\frac{{\mathrm{<figure-callout\; id="1"\; label="y"\; filenames="DE112019001018T5\_0017.png,DE112019001018T5\_0025.png"\; state="\{\{state\}\}">y</figure-callout>}}_1}{{\mathrm{A.}}_{Hys}}\right)\end{array}\\ \begin{array}{cc}\begin{array}{l}\text{When left}\\ \text{a hit}\end{array}& \text{b '}=x_1-\frac{1}{c}{\text{log}}_e\left(1+\frac{{\mathrm{<figure-callout\; id="1"\; label="y"\; filenames="DE112019001018T5\_0017.png,DE112019001018T5\_0025.png"\; state="\{\{state\}\}">y</figure-callout>}}_1}{{\mathrm{A.}}_{Hys}}\right)\end{array}\end{array}$$

A _hys = 1 [Nm], c = 0.3 is set in equations 5 and 6, and an example of a graphical representation of the hysteresis-corrected torque signal Tref_c with a control of +50 [deg], -50 [deg] starting from 0 [ deg] is in 8th shown. That is, the torque signal Tref_c from the hysteresis corrector 240 has a hysteresis characteristic as in the origin of 0 → L1 (thin line) → L2 (broken line) → L3 (thick line).

A _hys as the coefficient representing the output margin of the hysteresis characteristic and c as the coefficient representing the rounding can also be according to the vehicle speed Vs and / or the steering angle θh be changed.

The SAT data corrector 250 estimates based on the steering torque Ts , the motor angle θm and the motor current command value Imc, a self-aligning torque (SAT), further performs filtering, gain multiplication and control processing, and calculates a torque signal (first torque signal Tref_d). 9 Fig. 10 shows a structure example of the SAT data corrector 250 , where the SAT data corrector 250 a SAT estimator 251 , a filter component 252 , a control torque sensitivity enhancer 253 , a vehicle speed sensitivity enhancement term 254 , a steering angle sensitivity enhancement member 255 and a restriction component 256 includes.

Wobei ω_M und α_M die lenksäulenwellenkonvertierte (Konversion in einen auf die Lenksäulenwelle bezogenen Wert) Motorwinkelgeschwindigkeit und Motorwinkelbeschleunigung sind. Wird dann Gleichung 7 nach SAT aufgelöst, erhält man die folgende Gleichung 8.

$$T_{SAT}=T_m+T_s-J\cdot {\alpha }_M-Fr\cdot sign\left({\omega }_M\right)-D_M\cdot {\omega }_M$$

Wie aus Gleichung 8 ersichtlich, kann dadurch, dass die Lenksäulenwellen-Konversionsträgheit J, die statische Reibung Fr und der Dämpfungskoeffizient D_M als Konstanten vorab ermittelt werden, mittels der Motorwinkelgeschwindigkeit ω_M, der Motorwinkelbeschleunigung α_M, dem Hilfsdrehmoment Tm und dem Steuermoment Ts der selbstausrichtende Drehmomentwert (SAT-Wert) T_SAT geschätzt werden. Die Lenksäulenwellen-Konversionsträgheit J kann auch ein einfach mittels eines relationalen Ausdrucks der Motorträgheit und des Verzögerungsverhältnisses auf die Lenksäulenwelle konvertierter Wert sein.The state of the torque generated in the time from the road surface to the steering wheel is in 10 illustrated and explained. When the driver controls the steering wheel, a steering torque is generated Ts , and the steering torque Ts subsequently the engine generates 20th an auxiliary torque (steering column shaft conversion value of the motor torque) Tm. This deflects the vehicle wheels and the reaction force is SAT T _SAT . A steering column shaft conversion inertia (inertia acting on the steering column shaft by the (rotor of the) motor (s), the reduction gear, etc.) J and friction (static friction) Fr result in a torque that becomes the resistance of the steering wheel control. It also arises from the rotational speed of the motor 20th a physical torque (viscous torque) expressed as an attenuator (damping coefficient DM). Due to the balance of these forces, an equation of motion as in Equation 7 below is obtained. $$J\cdot {\alpha }_{\mathrm{M.}}+\mathrm{F.}r\cdot siGn\left({\omega }_{\mathrm{M.}}\right)+{\mathrm{D.}}_{\mathrm{M.}}\cdot {\omega }_{\mathrm{M.}}+T_{\mathrm{S.}\mathrm{A.}T}=T_m+T_s$$

In which ω _M and α _M the steering column shaft converted (conversion to a value related to the steering column shaft) motor angular velocity and motor angular acceleration. If equation 7 is then solved for SAT, the following equation 8 is obtained.

$$T_{\mathrm{S.}\mathrm{A.}T}=T_m+T_s-J\cdot {\alpha }_{\mathrm{M.}}-\mathrm{F.}r\cdot siGn\left({\omega }_{\mathrm{M.}}\right)-{\mathrm{D.}}_{\mathrm{M.}}\cdot {\omega }_{\mathrm{M.}}$$

As can be seen from equation 8, the fact that the steering column shaft conversion inertia J, the static friction Fr and the damping coefficient D _{M are determined} as constants in advance using the motor angular speed ω _M , the motor angular acceleration α _M , the auxiliary torque Tm and the control torque Ts the self-aligning torque value (SAT value) T _{SAT can be} estimated. The steering column shaft conversion inertia J may also be a value simply converted to the steering column shaft by means of a relational expression of the motor inertia and the deceleration ratio.

The SAT estimator 251 into which the control torque Ts , the motor angle θm and the motor current command value Imc are input, estimates the self-aligning torque (SAT value) T _SAT based on Equation 8. The motor current command value Imc becomes a conversion term 251A entered, and the steering column shaft-converted auxiliary torque Tm is calculated by multiplying it with a preset gear ratio and torque constant. The motor angle θm is put into an angular velocity calculator 251B input, and by a differential calculation and division by the translation a steering column shaft converted motor angular speed ω _M calculated. In an angular acceleration calculation component 251C is determined by a differential calculation using the motor angular velocity ω _M a steering column shaft converted engine angular acceleration α _M calculated. Then by means of the entered control torque Ts and the calculated auxiliary torque Tm, the motor angular speed ω _M and the motor angular acceleration αM based on equation 8 by the in 9 The structure shown, the SAT value T _{SAT is} calculated. In 9 acts block 251D as a marker function and outputs a marker of entered data, block 251E multiplies the entered data by the damping coefficient D _M and print it out, block 251F multiplies the inputted data by the static friction Fr and outputs it, and block 251G multiplies the entered data by the steering column shaft conversion inertia J and outputs it. If the steering column angle can be detected directly, the steering column angle can also be used as angle information instead of the motor angle θm. In this case, no steering column shaft conversion is required. Furthermore, instead of the motor angle θm, a steering column wave-converted signal of the motor angular velocity ωm of the EPS control system / vehicle system can also be used 100 as motor angular speed ω _M and a differential calculation of the motor angle θm can be omitted. In addition, the SAT value T _{SAT can} also be estimated using a different method, or a measured value can be used instead of an estimated value.

To that in the SAT estimator 251 practical use of the estimated SAT value T _SAT and appropriately conveyed to the driver as a control feeling is by means of the filter component 252 the information to be transmitted is extracted from the SAT value T _SAT , which is generated by means of the control torque sensitivity amplification element 253 , the vehicle speed sensitivity gain term 254 and the steering angle sensitivity enhancement member 255 to be transferred and also by means of the constraint component 256 the upper and lower limit value adjusted. The filter component 252 leads z. B. filtering the SAT value T _SAT by means of a bandpass filter and outputs SAT data T _ST 1. The control torque sensitivity enhancer 253 multiplies one according to the control torque Ts set control torque sensitivity gain with the SAT data T _ST 1 and outputs SAT data T _ST 2. In order to increase the sensitivity in the vicinity of the center, which is a straight-ahead driving state, the control torque sensitivity gain z. B. as in 11 shown set. That is, the control torque sensitivity gain becomes at a control torque Ts of less than or equal to Ts1 (e.g. 2 Nm) set to 1.0, with a control torque Ts of greater than or equal to Ts2 (> Ts1) (e.g. 4 Nm) set to a value that is less than 1.0, and at a control torque Ts set between Ts1 and Ts2 such that it decreases in a certain ratio. The vehicle speed sensitivity enhancement term 254 multiplies one according to the vehicle speed Vs Set vehicle speed sensitivity gain with the SAT data T _ST 2 and outputs SAT data T _ST 3. In order to increase the sensitivity at a high speed, the vehicle speed sensitivity gain is e.g. B. as in 12 shown set. That is, the vehicle speed sensitivity gain is set at a vehicle speed Vs of greater than or equal to Vs2 (e.g. 70 km / h) is set to 1.0 at a vehicle speed Vs is set from less than or equal to Vs1 (<(Vs2) (e.g. 50 km / h) to a value less than 1.0 and at a vehicle speed Vs between Vs1 and Vs2 adjusted so that it increases in a certain ratio. The steering angle sensitivity enhancement member 255 multiplies one according to the steering angle θh set steering angle sensitivity gain with the SAT data T _ST 3 and gives a torque signal Tref_d0 out. In order to increase the sensitivity at a large steering angle starting with the effect from a certain steering angle, the steering angle sensitivity gain z. B. as in 13 shown set. That is, the steering angle sensitivity gain becomes at a steering angle θh of less than or equal to θh1 (e.g. 10 deg) by a specific gain value Gα, at a steering angle θh of greater than or equal to θh2 (e.g. 30 deg) is set by 1.0, and at a steering angle θh between θh1 and θh2 are set to increase by a certain ratio. To increase the sensitivity at a large steering angle, z. B. a setting of Gα in a range of 0 Gα <1. In order to increase the sensitivity with a small steering angle, a setting of is suitable, without this being shown here Gα in a range of 1 <Gα. If the sensitivity is not to be changed in accordance with the steering angle, a setting of Gα = 1 is suitable. For the restriction component 256 as in 14th shown, an upper limit value and a lower limit value corresponding to the torque signal are preset, and if the inputted torque signal Tref_d0 is greater than or equal to the upper limit value, the upper limit value, if it is less than or equal to the lower limit value, becomes the lower limit value, and otherwise the torque signal Tref_d0 as Torque signal Tref_d issued. The steering torque sensitivity gain, the vehicle speed sensitivity gain and the steering angle sensitivity gain can also be used, as in FIG 11 , 12 and 13 instead of linear characteristics, curved characteristics, or they can be suitably adjusted according to the control feeling or e.g. B. be adapted to the maximum value or minimum value of the respective gain. If an increase in the magnitude of the torque signal is not to be feared, or if the control is carried out by some other means, the restriction component 256 can also be omitted. The control torque sensitivity enhancer 253 , the vehicle speed sensitivity enhancement term 254 and the steering angle sensitivity enhancement member 255 can also be omitted in a suitable manner or their insertion position exchanged. The respective gains can be determined in parallel or by a structure in which the SAT data T _ST 1 is multiplied at one point.

The torque signals determined as described above Tref_d , Tref_c , Tref_b and Tref_a are made by the adders 263 , 262 and 261 are added in turn, and the final addition result is output as the target control torque Tref.

The steering angle speed ωh is determined by a differential calculation with respect to the steering angle θh but appropriate low pass filtering (LPF) is performed to reduce the influence of interference in a high range. A differential calculation and LPF filtering can also be carried out by means of a high-pass filter (HPF) and the gain. The steering angle speed ωh can also be calculated in that the differential calculation and LPF filtering are not related to the steering angle θh but with regard to the steering wheel angle detected by the upper angle sensor θ ₁ or the steering column angle detected by the lower angle sensor θ ₂ respectively. Instead of the steering angle speed ωh The motor angular velocity ωm can also be used as angular velocity information, in which case no differentiating element 220 is needed.

A conversion component 500 exhibits the characteristic -1 / Kt of the inverted marking of the reciprocal of the spring constant Kt of the torsion bar 2A and converts the target control torque Tref into the target rotation angle Δθref.

The twist angle control component 300 calculates the motor current command value Imc based on the target twist angle Δθref, the twist angle Δθ and the motor angular velocity ωm. 15th Fig. 13 is a block diagram showing a structural example of the twist angle control component 300 shows where the twist angle control component 300 a twist angle feedback (FB) compensation element 310 , a twisting angular velocity calculator 320 , a speed controller 330 , a stabilization compensation element 340 , an output restriction member 350 , a subtracter 361 and an adder 362 comprises, an addition input of the from the conversion component 500 output target rotation angle Δθref into the subtracter 361 , a subtract input of the twist angle Δθ to the subtracter 361 and an input to the twist angular velocity calculator 320 , and an input of the motor angular velocity ωm to the stabilization compensation term 340 he follows.

The twist angle feedback compensation element 310 multiplies the deviation Δθ ₀ between that by the subtracter 361 calculated target rotation angle Δθref and the rotation angle Δθ with a compensation value C _FB (Transfer function), and outputs a set rotation angle speed ωref at which the rotation angle Δθ follows the set rotation angle Δθref. The compensation value C _FB can also be a simple gain Kpp or a commonly used compensation value such as B. be a compensation value of the PI control. The target twist angular speed ωref is entered in the speed controller 330 entered. Through the twist angle FB compensation element 310 and the speed controller 330 a desired control torque can be realized at which the twisting angle Δθ follows the target twisting angle Δθref.

The twist angular velocity calculator 320 calculates the twisting angular velocity ωt through a differential calculation with respect to the twisting angle Δθ, and the twisting angular velocity ωt is entered in the speed controller 330 entered. An affine differentiation using HPF and reinforcement can also be carried out as a differential calculation. Furthermore, the twisting angular velocity ωt can also be calculated by a means other than the twisting angle Δθ and entered into the speed control member 330 can be entered.

The speed controller 330 calculates a motor current command value Imca1, at which the angular rotation speed ωt follows the set angular rotation speed wref, by an IP control (proportion anticipatory PI control). Through a subtracter 333 the difference (ωref - ωt) between the target angular rotation speed ωref and the angular rotation speed ωt is calculated, this difference is calculated in an integrator having a gain Kvi 331 integrated and an addition input of the integration result to a subtracter 334 he follows. The angular rotation speed ωt is also converted into a proportionalizer 332 is entered, a proportionalization is carried out by means of the gain Kvp and a subtraction is input into the subtracter 334 . The subtraction result of the subtracter 334 is output as the motor current command value Imca1. The speed controller 330 The motor current command value Imca1 can also not be determined by an IP control but by a generally used control method such as PI control, P (proportional) control, PID (proportional integral differentiation) control, PI-D control (differential anticipatory PID control ), Pattern matching control, or model reference control.

Dabei ist K_sta die Verstärkung und fc die Übergangsfrequenz, wobei als fc z. B. 150 [Hz] eingestellt ist. Als Übertragungsfunktion kann auch ein Filter zweiter Ordnung oder ein Filter vierter Ordnung verwendet werden.The stabilization compensation element 340 has a compensation value Cs (transfer function), and calculates a motor current command value Imca2 using the motor angular velocity ωm. Is used to improve the tracking and disturbance characteristics, the amplification of the angle of rotation compensation element 310 and the speed control member 330 increased, a control-related oscillation phenomenon occurs in the high frequency wave range. As a countermeasure, the stabilization compensation member 340 the transfer function (Cs) required for stabilization is set for the motor angular velocity ωm. As a result, the entire EPS control system can be stabilized. As the transfer function (Cs) of the stabilization compensation element 340 can e.g. For example, a first-order filter can be used which is set by means of affine differentiation using the construction of a first-order HPF and the gain and is expressed by Equation 9 below.

$${\mathrm{C.}}_s=K_{sta}\frac{\frac{1}{2\pi f_c}s}{\begin{array}{c}1\\ 2\pi f_c\end{array}s+1}$$

Here, K _{sta is} the gain and fc is the transition frequency, where fc z. B. 150 [Hz] is set. A second-order filter or a fourth-order filter can also be used as the transfer function.

The motor current command value Imca1 of the speed control member 330 and the motor current command value Imca2 of the stabilization compensator 340 are in the adder 362 added and output as the motor current command value Imcb.

The output constraint member 350 restricts the upper and lower limit values of the motor current command value Imcb and outputs the motor current command value Imc. As is the case with the restriction component 256 in the SAT data corrector 250 the upper limit value and the lower limit value for the motor current command value Imcb are restricted by a presetting.

An operational example of the present embodiment having this structure will be explained with reference to the flowcharts in FIG 16 to 18th explained.

At the start of the operation, the motor angular velocity ωm is included in the right hand / left hand judging component 400 which judges whether the control is a right-hand turn or a left-hand turn based on the flag of the motor angular velocity ωm, and the judgment result as the control state STs to the target control torque generation component 200 outputs (step S10 ).

Along with the tax status STs become the steering angle θh , the vehicle speed Vs , the control moment Ts , the motor angle θm and the motor current command value Imc into the target control torque generation component 200 entered that the target control torque Meeting generated (step S20 ). An operational example of the target control torque generation component 200 is based on the flowchart in 17th explained.

The steering angle input into the target control torque generation component θh is in the basic map element 210 , the differentiator 220 , the hysteresis correction element 240 and the SAT data corrector 250 entered, the control state STs is in the hysteresis correction element 240 entered the vehicle speed Vs is in the basic map element 210 , the attenuation gain link 230 and the SAT data corrector 250 entered, and the control torque Ts , the motor angle θm and the motor current command value Imc are entered in the SAT data corrector 250 entered (step S21 ).

The basic map element 210 generated using the in 6th basic map shown on the steering angle θh and the vehicle speed Vs corresponding torque signal Tref_a and gives it to the adder 261 off (step S22 ).

The differentiator 220 differentiates the steering angle θh and gives the steering angular speed ωh off (step S23 ), the damping gain link 230 uses the in 7th The damping gain map shown is that of the vehicle speed Vs appropriate Damping reinforcement D _G off (step S24 ), the multiplier 260 calculated by multiplying the steering angle speed ωh with the damping gain D _G the torque signal Tref_b and gives it to the adder 262 off (step S25 ).

The hysteresis correction element 240 leads in the steering angle θh by rearranging the calculation using Equation 5 and Equation 6 according to the control status STs a hysteresis correction (step S26 ), generates the torque signal Tref_c and gives it to the adder 263 off (step S27 ). The hysteresis _margin A _hys , c, x1 and y1 in equation 5 and equation 6 are preset and are retained, but it is also possible to calculate in advance using equations 6b and b 'and to keep b and b' instead of x1 and y1.

The SAT data corrector 250 inputs the inputted motor current command value Imc and the motor angle θm, respectively, to the SAT estimator 251 , the control moment Ts into the SAT estimator 251 and into the control torque sensitivity enhancer 253 , the vehicle speed Vs into the vehicle speed sensitivity enhancement term 254 , and the steering angle θh into the steering angle sensitivity enhancement member 255 one. The SAT estimator 251 calculated in the conversion term 251A based on the motor current command value Imc, the auxiliary torque Tm in the angular velocity calculator 251B the motor angular velocity based on the motor angle θm ω _M and further an angular acceleration calculator 251C the motor angular acceleration α _M , and using this and the control torque calculates the SAT value T _SAT based on equation 8 (step S28 ). The calculated SAT value T _SAT is used in the filter component 252 filtered and as SAT data T _ST 1 to the control torque sensitivity gain element 253 output (step S29 ). The control torque sensitivity enhancer 253 determined using the in 11 The characteristic shown corresponds to the inputted control torque Ts corresponding control torque sensitivity gain, multiplies this by the SAT data T _ST 1 and sends this as SAT data T _ST 2 to the vehicle speed sensitivity gain element 254 off (step S30 ). The vehicle speed sensitivity enhancement term 254 determined using the in 12 The characteristic shown is one of the entered vehicle speed Vs corresponding vehicle speed sensitivity gain, multiplies this with the SAT data T _ST 2 and sends this as SAT data T _ST 3 to the steering angle sensitivity gain element 255 off (step S31 ). The steering angle sensitivity enhancement member 255 determined using the in 13 The characteristic shown corresponds to the entered steering angle θh corresponding steering angle sensitivity gain, multiplies this with the SAT data T _ST 3 and outputs this as a torque signal Tref_d0 to the restriction component 256 off (step S32 ). The restriction component 256 limits the upper and lower limit value of the torque signal Tref_d0 by means of a preset upper limit value and lower limit value and outputs this as a torque signal Tref_d to the adder 263 off (step S33 ).

Then in the adder 263 the torque signals Tref_c and Tref_d is added to the addition result in the adder 262 the torque signal Tref_b added, and also to this addition result in the adder 261 the torque signal Tref_a added, and the target control torque Meeting calculated (step S34 ).

That in the target control torque generation component 200 generated target control torque Meeting becomes the conversion component 500 entered and through the conversion component 500 converted into the target rotation angle Δθref (step S40 ). The target twist angle Δθref is included in the twist angle control component 300 entered.

Together with the target angle of rotation Δθref, the angle of rotation Δθ and the motor angular velocity ωm are included in the angle of rotation control component 300 which calculates the motor current command value Imc (step S50 ). An example of operation of the twist angle control component 300 is based on the flowchart in 18th explained.

The one in the twist angle control component 300 input target rotation angle Δθref is entered into the subtracter 361 , the twist angle Δθ in the subtracter 361 and the twisting angular velocity calculating section 320 , and the motor angular velocity ωm into the stabilization compensation term 340 each entered (step S51 ).

In the subtracter 361 is obtained by subtracting the angle of rotation Δθ the deviation from the target angle of rotation Δθref Aθ ₀ calculated (step S52 ). The deviation Δθ0 is included in the angle of rotation FB compensation element 310 entered, and the angle of rotation FB compensation element 310 compensated by multiplying the deviation Δθ ₀ with the compensation value C _FB the deviation Δθ0 (Step S53 ), and outputs the target angular rotation speed ωref to the speed control member 330 out.

The twist angular velocity calculator 320 into which the twist angle Δθ was entered, calculated by a differential calculation with respect to the angle of rotation Δθ the angular rotation speed ωt (step S54 ) and gives it to the speed controller 330 out.

In the speed controller 330 becomes the difference between the target angular rotation speed ωref and the angular rotation speed ωt through the subtracter 333 calculated this difference by the integrator 331 (Kvi / s) and there is an addition input into the subtracter 334 (Step S55 ). In addition, the angular rotation speed ωt is determined by the proportionalization element 332 proportionalized (Kvp), and the proportional result is subtracted into the subtractor 334 (Step P.56 ), and the motor current command value Imca1 as the subtraction result of the subtracter 334 output, and into the adder 362 entered.

The stabilization compensation element 340 carries out a stabilization compensation of the entered motor angular velocity ωm by means of the transfer function Cs given in equation 9 (step P.56 ), and the motor current command value Imca2 of the stabilization compensation element 340 gets into the adder 362 entered.

In the adder 362 the addition of the motor current command values Imca1 and Imca2 (step S57 ), and the motor current command value Imcb, which is the addition result, is put into the output restricting term 350 entered. The output constraint member 350 limits the upper and lower limit values of the motor current command value Imcb by the preset upper limit value and lower limit value (step S58 ) and outputs this as a motor current command value Imc (step S59 ).

Based on that from the twist angle control component 300 When the motor current command value Imc is output, the motor is driven and the current control is carried out (step S60 ).

The order of data entry and calculations in 16 to 18th can be changed appropriately.

The effects of the SAT data corrector in the present embodiment will be explained based on simulation results.

First, the simulation result is shown without the presence of a SAT data correction element. As in 19 (A) shown, the SAT value extends over 10 seconds at a frequency between 1 Hz and 10 Hz, and 19 (B) shows the state of the change in the control torque with a sinusoidal excitation with an amplitude of 1 Nm. In 19th the x-axis is time [sec], and the y-axis is in 19 (A) the SAT value [Nm] and in 19 (B) the control torque [Nm]. Furthermore, the SAT value is a steering column shaft converted value, where the steering angle θh is constant 0 [deg].

In 19 (B) the target control torque is shown with a thin line and the control torque is shown with a thick line, both of which substantially overlap. If no correction is made by the SAT data correction element, the setpoint control torque essentially becomes 0 Nm, and based on this there is no follow-up control by the angle of rotation control component, so that the control torque ultimately also becomes 0 Nm.

Next, the simulation result is displayed with a SAT data corrector. As a filter of the filter component, a second-order band-pass filter having a center frequency of 5 Hz is used and it is used in the same manner as in FIG 19 (A) excited SAT value filtered, the filtered SAT data multiplied by the control torque sensitivity gain, the vehicle speed sensitivity gain and the steering angle sensitivity gain, and the determined torque signal Tref_d together with the SAT value in 20 (A) shown (the thick line is the torque signal Tref_d , and the thin line of the SAT value), and the state of change in the target steering torque and the actual steering torque in 20 (B) is shown. The parameters of the x-axis and the y-axis in 20th are the same as at 19th .

Also in 20 (B) the target control torque is shown with a thin line and the control torque is shown with a thick line, both of which substantially overlap. If the SAT value (thin line) in 20 (A) with the control torque in 20 (B) compared, it can be seen that the control torque follows the SAT value as the target. This means that the SAT value in the vicinity of 5 Hz (temporally in the vicinity of 4 to 5 seconds) can be implemented as a control moment.

In the simulation, a second-order bandpass filter was used as the filter of the filter component, although there is no restriction to the second order and a filter of a different order can also be used.

With the filter component 252 in the SAT data corrector 250 In the first embodiment, the filtering is carried out with a filter, with a plurality of data that are to be communicated to the driver and different band areas in which these data are present, also filtering with a plurality of filters connected in parallel with the respective band areas as a pass band area can be done. Should z. B. three data are transmitted, the filter component, as in the structural example in 21st (second embodiment) consist of three filters connected in parallel. In this case, filters are in 652A , 652B and 652C inside the filter component 652 SAT- Data T _SAT input, the outputs of the respective filters in the adder 652D added and output as SAT data T _ST 1. The number of connected filters can be selected as required, adapted to the number of data to be transmitted.

The target control torque generation component 200 in the first embodiment, the basic map element comprises 210 , the attenuation calculator (attenuation gain term 230 or multiplier 260 ), the hysteresis correction element 240 and the SAT data corrector 250 , whereby also a structure with only one SAT data correction element specialized in SAT-related processing 250 is possible. 22nd Fig. 13 shows a structural example of a target control torque generation component (third embodiment) in this case. By a target control torque generation component 700 this is done by the SAT data corrector 250 output torque signal Tref_d as the target control torque Meeting issued. The target control torque generation component can also consist of a combination of the basic map element 210 , at least either one attenuation calculator or the hysteresis corrector 240 , and the SAT data corrector 250 consist.

It is also possible to add a current command value (hereinafter “auxiliary current command value”) calculated based on the control torque in a conventional EPS to the motor current command value Imc output by the twist angle control component of the first to third embodiments. B. from the in 2 current command value calculation component shown 31 output current command value Iref1 or a current command value Iref 2 from the addition of the current command value Iref 1 and the compensation signal CM to add up.

23 Fig. 13 shows a structural example of applying the above to the first embodiment (fourth embodiment). An auxiliary control component 800 consists of the current command value calculation component 31 , or the current command value calculation component 31 , the compensation signal generation component 34 and the adder 32A . The current control is carried out by the auxiliary control component 800 output auxiliary current command value lac (corresponding to the current command value Iref1 or Iref2 in 2 ) and that of the angle of rotation control component 300 output motor current command value Imc by an adder 810 are added, the current command value Ic representing the addition result into a current restriction component 820 is input, and the motor is driven based on the current command value Icm restricted to a maximum current. Into the target control torque generation component 200 instead of the motor current command value Imc, the current command value Icm is inputted and for the estimation of the SAT value T _{SAT of} the SAT estimator 251 in the SAT data corrector 250 used. A motor current detection value can also be used in place of the current command value Icm.

The basic map element 210 comprehensive target control torque generation component 200 in the first to fourth embodiments, the basic map element 210 A phase compensation element is also connected upstream or downstream 270 be used, which carries out a phase compensation. That is, the structure of the in 5 Area R surrounded by a dashed line can also include the in 24 (A) or (B) have the structure shown. If at the phase compensation element 270 a phase lead compensation set as phase compensation and z. B. a phase lead compensation with a cutoff frequency of the denominator of 1.0 Hz and the cutoff frequency of the numerator of 1.3 Hz by means of a first-order filter, a feeling of well-being can be realized. The target control torque generation component is not limited to the above structure as long as it is a structure based on the steering angle.

Furthermore, the stabilization compensation element can also be omitted in a stable EPS control system. The output restriction component can also be omitted.

In 1 and 3 the present invention is applied to a steering column EPS, but the present invention is not applicable to an overflow type such as B. limited a steering column, but also on an underflow type, such. B. a rack and pinion applicable. In addition, when executing a feedback control based on the target rotation angle, it can also be applied to a steering-by-wire (SBW) reaction force device that includes at least one torsion bar (any spring constant) and a sensor for detecting the rotation angle. An embodiment (fifth embodiment) applying the present invention to an SBW reaction force device having a torsion bar will now be explained.

First, the whole SBW system including the SBW reaction force device will be explained. 25th FIG. 13 is a view showing a structural example of the SBW system corresponding to that in FIG 1 shows the general structure of an electric power steering apparatus shown. The same structures are given the same reference symbols and their explanations are omitted.

With the SBW system, there are none on the universal joint 4a with the steering column shaft 2 mechanically connected intermediate shaft, so that it is a system in which the operation of the steering wheel 1 by means of electrical signals to the steering mechanism from the steered vehicle wheels 8L , 8R etc. is transmitted. As in 25th As shown, the SBW system includes a reaction force device 60 and a drive device 70 , and the two devices are controlled by a control unit (ECU) 50 . The reaction force device 60 leads by means of the steering angle sensor 14th a detection of the steering angle θh and at the same time transmits the information from the steered vehicle wheels 8L , 8R transmitted driving state of the vehicle as a reaction force torque on the driver. The reaction force moment is generated by a reaction force motor 61 generated. Although there are SBW systems with no torsion bar in the reaction force device, the SBW system to which the present invention is applied is an SBW system with a torsion bar and the control torque Ts is by means of the torque sensor 10 detected. An angular velocity sensor also detects 74 the motor angle θm of the reaction force motor 61 . The drive device 70 drives adapted to the control of the steering wheel 1 by the driver a drive motor 71 on, this driving force is via a pinion 72 to the rack and pinion mechanism 5 applied, and about tie rods 6a , 6b are the steered vehicle wheels 8L , 8R controlled. Near the rack and pinion mechanism 5 is an angle sensor 73 arranged and detects the turning angle θt of the steered vehicle wheels 8L , 8R . For harmonization control of the reaction force device 60 and the drive device 70 generates the ECU 50 in addition to the data of the steering angle θh and the turning angle θt output from the two devices based on that from the vehicle speed sensor 12 output vehicle speed Vs one the reaction force motor 61 drive-controlling voltage control command value Vref1 and a drive motor 71 drive-controlling voltage control command value Vref2.

The construction of the fifth embodiment in which the present invention is applied to the SBW system will now be explained.

26th Fig. 13 is a block diagram showing the construction of the fifth embodiment. In the fifth embodiment, the twist angle is controlled Δθ (hereinafter “twist angle control”) and a control of the deflection angle Δt (hereinafter “deflection angle control”), wherein the reaction force device is controlled by the twist angle controller and the drive device is controlled by the deflection angle controller. The drive device can also be controlled by another control method.

In the twist angle control, the twist angle is performed by an equivalent structure and operation as in the first embodiment Δθ one by means of the steering angle θh via the target control torque generation component 200 and conversion component 500 calculated target rotation angle Δθref following control, wherein in the target control torque generation component 200 instead of that by the twist angle control component 300 calculated motor current command value Imc by a deflection angle control component 920 calculated motor current command value Imct and instead of the motor angle θm the deflection angle θt is input. The motor angle θm is determined by the angle sensor 74 is detected and the motor angular velocity ωm is determined by differentiating the motor angle θm by an angular velocity calculator 951 calculated. The deflection angle θt is determined by the angle sensor 73 detected. The SAT data corrector 250 in the target control torque generation component 200 can also make SAT estimation by considering the drive device to be inertia (or mass). That is, since the turning angle θt is used in place of the motor angle θm, the steering column shaft conversion inertia J, the static friction Fr, and the damping coefficient DM are given as parameters adapted to the drive device, and there is no torsion bar in the drive device, the control torque Ts regarded as 0 and estimated SAT. In the first embodiment, this was not done as processing inside the EPS control system / vehicle system 100 explained in detail, but the power control component 130 performs by means of an equivalent structure and operation as the subtracter 32B , the PI control component 35 , the PWM control component 36 and the inverter 37 , in the 2 are shown by a drive of the reaction force motor 61 based on a based on the from the twist angle control component 300 output motor current command value Imc and that by the motor current detector 140 detected current value Imr for the reaction force motor 61 a current control by.

In the case of the deflection control, the target deflection angle generation component 910 based on the steering angle θh the target deflection angle θtref is generated, the target deflection angle θtref is used together with the deflection angle θt in the deflection angle control component 920 entered, and in the deflection angle control component 920 the motor current command value Imct at which the turning angle θt becomes the target turning angle θtref is calculated. Then the electricity control component leads 930 based on the motor current command value Imct and that by the motor current detector 940 detected current value Imd of the drive motor 71 by means of an equivalent structure and operation as in the Electricity control component 130 by the drive of the drive motor 71 a current control by.

A structural example of the target deflection angle generating component 910 is in 27 shown. The target deflection angle generation component 910 includes a restriction component 931 , a rate limiter 932 and a correction link 933 .

The restriction component 931 limits the upper and lower limit value of the steering angle θh and gives the steering angle θh1 out. As is the case with the restriction component 256 in the SAT data corrector 250 and at the output restriction member 350 in the angle of rotation control component 300 become the upper limit value and the lower limit value for the steering angle θh limited by a preset.

The rate limiter 932 restricts the amount of change in the steering angle by setting a restriction value θh1 and outputs a steering angle θh2 to avoid sudden change in the steering angle. Is z. B. the difference to the steering angle θh1 of the previous cycle given as the amount of change, when the absolute value of this amount of change is larger than a certain value (restriction value), the steering angle becomes θh1 added or subtracted and outputted as the steering angle θh2 so that the absolute value of the amount of change becomes the restriction value, and when it is less than or equal to the restriction value, the steering angle becomes θh1 output unchanged as θh2. It is also possible not to set a restriction value for the absolute value of the change amount, but to restrict the change amount by setting an upper limit value and lower limit value, or to restrict not the change amount but the change rate or the difference rate.

The correction link 933 corrects the steering angle θh2 and outputs the target turning angle θtref. For example, as with the basic map element 210 in the target control torque generation component 200 , by means of a map which maps the characteristic of the target deflection angle θtref to the quantity | θh2 | the steering angle θh2 defined by the steering angle θh2 the target deflection angle θtref is determined. Or the target deflection angle θtref can also be determined simply by multiplying the steering angle θh2 can be determined with a certain gain.

28 Fig. 13 shows a structural example of the turning angle control component 920 . The deflection angle control component 920 has apart from the stabilization compensation element 340 and the adder 362 one to the structural example of the in 15th twist angle control component shown 300 equivalent structure, where instead of the target angle of rotation Δθref and the angle of rotation Δθ the target deflection angle θtref and the deflection angle θt are input, and through a deflection angle feedback (FB) compensation element 921 , a turning angular velocity calculator 922 , a speed controller 923 , an output restriction member 926 and a subtracter 927 each by an equivalent structure to that of the torsion angle FB compensation element 310 , the twist angular velocity calculator 320 , the speed controller 330 , the issue restriction member 350 and the subtracter 361 an equivalent operation takes place.

An operational example of the fifth embodiment having this structure will be explained with reference to the flow chart in FIG 29 explained.

The angle sensor detects at the start of operation 73 the deflection angle θt and the angle sensor 74 detects the motor angle θm (step S110 ), where in each case the deflection angle θt in the target control torque generation component 200 and the turning angle control component 920 , and the motor angle θm in the angular velocity calculator 951 is entered.

The angular velocity calculator 951 calculates the motor angular speed ωm by differentiating the motor angle θm, and outputs it to the right-hand turn / left-hand turn judgment component 400 and the twist angle control component 300 off (step S120 ).

Then, in the target control torque generation component 200 by means of the motor current command value Imct in place of the motor current command value Imc and the deflection angle θt in place of the motor angle θm, an equivalent operation as in FIGS 16 steps shown S10 to S60 running the reaction engine 61 operated and current control carried out (steps S130 to S170 ).

On the other hand, in the turning angle control, there is the target turning angle generation component 910 the steering angle θh one and the steering angle θh becomes in the restriction component 931 entered. The restriction component 931 limits the upper and lower limit value of the steering angle θh using a preset upper limit value and lower limit value (step S180 ) and gives this as a steering angle θh1 to the rate limiting member 932 out. The rate limiter 932 restricts the amount of change in the steering angle θh1 by a preset limit value (step S190 ) and gives this as a steering angle θh2 to the correction link 933 out. The correction link 933 corrects the steering angle θh2 , determines the target Deflection angle θtref (step S200 ) and sends this to the deflection angle control component 920 out.

The deflection angle control component 920 , into which the turning angle θt and the target turning angle θtref have been input, calculated by subtracting the turning angle θt from the target turning angle θtref in the subtracter 927 the deviation Δθt ₀ (step S210 ). The deviation Δθ ₀ is in the deflection angle FB compensation element 921 entered, and the deflection angle FB compensation element 921 compensated for by multiplying the deviation Δθt ₀ with the compensation value, the deviation Δθt ₀ (step S220 ), and outputs the target deflection angular speed ωtref to the speed control element 923 out. The turning angular velocity calculator 922 , into which the turning angle θt has been input, calculates the turning angular velocity ωtt through a differential calculation with respect to the turning angle θt (step S230 ) and sends this to the speed control element 923 out. The speed controller 923 calculated equivalent to the speed controller 330 the motor current command value Imcta (step S240 ) and passes it on to the output restriction member 926 out. The output restriction member 926 limits the upper and lower limit values of the motor current command value Imcta by the preset upper limit value and lower limit value (step S250 ) and outputs this as a motor current command value Imct (step S260 ).

The motor current command value Imct is put into the target control torque generation component 200 and into the power control component 930 and based on the motor current command value Imct and that by the motor current detector 940 detected current value Imd of the drive motor 71 drives the electricity control component 930 the drive motor 71 and executes power control (step S270 ).

The order of data entry and calculations in 29 can be changed appropriately. Furthermore, the speed control member 923 in the deflection angle control component 920 equivalent to the speed controller 330 in the angle of rotation control component 300 do not execute IP control but PI control, P control, PID control, PI-D control, etc., using one control of P, I, or D suffice, and besides, the follow-up control can be performed at the deflection angle control component 920 and the twist angle control component 300 can also be performed by a commonly used control structure.

In the fifth embodiment, as in FIG 25th shown with an ECU 50 the control of the reaction force device 60 and the drive device 70 , but there can also be one ECU for each reaction force device 60 and an ECU for the drive device 70 be provided. In this case, data is sent and received between the ECUs by means of a transmission. The in 25th SBW system shown exists between the reaction force device 60 and the drive device 70 not a mechanical connection, however, the present invention is also applicable to an SBW system that includes a mechanical torque transmission structure that drives the steering column shaft when an abnormality occurs in the system 2 and mechanically connects the deflection structure by a coupling, etc. In such an SBW system, in the normal state of the system, the clutch is switched off and the mechanical torque transmission is in an open state, and in the event of a system abnormality, the clutch is switched on and the mechanical torque transmission is enabled.

The twist angle control component 300 in the first to fifth embodiments and the auxiliary control component 800 In the fourth embodiment, it calculates the motor current command value Imc and the auxiliary current command value lac directly, but before the respective calculations, the motor torque to be output (target torque) can be calculated first and then the motor current command value and the auxiliary current command value can be calculated. In this case, for obtaining the motor current command value and the auxiliary current command value from the motor torque, the generally used relationship between the motor current and the motor torque is used.

List of reference symbols

1

steering wheel

2

Steering column shaft (steering shaft, steering wheel shaft)

2A

Torsion bar

3

Reduction gear

10

Torque sensor

12

Vehicle speed sensor

14th

Steering angle sensor

20th

engine

30, 50

Control unit (ECU)

31

Current command value calculation component

33, 820

Current limiting component

34

Compensation signal generation component

38, 140, 940

Motor current detector

60

Reaction force device

61

Reaction force motor

70

Drive device

71

Drive motor

72

pinion

73, 74

Angle sensor

100

EPS control system / vehicle system

130, 930

Electricity control component

200,700

Target control torque generation component

210

Basic map element

211

Marker member

230

Attenuation gain link

240

Hysteresis correction element

250

SAT data corrector

251

SAT estimator

251A

Conversion link

251B, 951

Angular velocity calculator

251C

Angular acceleration calculator

252, 652

Filter component

253

Control torque sensitivity enhancer

254

Vehicle speed sensitivity gain term

255

Steering angle sensitivity gain element

256.931

Constraint Component

270

Phase compensation element

300

Twist angle control component

310

Angle of rotation feedback (FB) compensation element

320

Twist angular velocity calculator

330, 923

Speed control member

340

Stabilization compensation element

350.926

Output restriction member

400

Right-hand-hand / left-hand-hand judge

500

Conversion component

800

Auxiliary control component

910

Target deflection angle generating component

920

Deflection angle control component

921

Deflection angle feedback (FB) compensation element

922

Deflection angular velocity calculator

932

Rate Limiter

933

Correction link

QUOTES INCLUDED IN THE DESCRIPTION

This list of the documents listed by the applicant was generated automatically and is included solely for the better information of the reader. The list is not part of the German patent or utility model application. The DPMA assumes no liability for any errors or omissions.

Patent literature cited

• JP 5208894 B2 [0009, 0010]
• JP 2008 [0019]
• JP 216172 A [0019]

Claims (11)

A vehicle steering device comprising at least one torsion bar having an arbitrary spring constant and a sensor detecting the twisting angle of the torsion bar, and through the drive control of the motor, an auxiliary control of the steering control system executes a target control torque generating component, a target -Conversion component converting the control torque into a target angle of rotation and a torque angle control component which calculates a motor current command value such that the angle of rotation follows the desired angle of rotation, characterized in that the target control torque generating component is equipped with a SAT data correction element, which calculates a first torque signal based on a self-aligning torque value and outputs the first torque signal as a target control torque, and the SAT data corrector with a SAT estimator which, based on the control torque, the angle inf ormation and the motor current command value estimates the self-aligning torque value, and is equipped with a filter component that calculates the first torque signal by filtering on the self-aligning torque value, and the motor is drive-controlled based on the motor current command value. Vehicle steering device according to Claim 1 , wherein the filter component consists of one or a plurality of filters connected in parallel. Vehicle steering device according to Claim 1 or 2 wherein the SAT data corrector is further provided with a control torque sensitivity gain that multiplies the first torque signal by a control torque sensitivity gain. Vehicle steering device according to Claim 3 , wherein the control torque sensitivity gain is set to be larger in the center. Vehicle steering device according to one of the Claims 1 to 4th wherein the SAT data corrector is further provided with a vehicle speed sensitivity gain that multiplies the first torque signal by a vehicle speed sensitivity gain. Vehicle steering device according to Claim 5 wherein the vehicle speed sensitivity gain is set to become larger at a high speed. Vehicle steering device according to one of the Claims 1 to 6th wherein the SAT data corrector is further provided with a steering angle sensitivity gain member that multiplies the first torque signal by a steering angle sensitivity gain. Vehicle steering device according to one of the Claims 1 to 7th wherein the SAT data corrector is further provided with a restriction component that restricts the first torque signal by an upper and lower limit value. Vehicle steering device according to one of the Claims 1 to 8th , wherein the target control torque generation component with a basic map element that determines the steering angle by means of a basic map and a second torque signal based on the vehicle speed, a damping calculator that determines a third torque signal by means of a vehicle speed-sensitive damping map based on angular velocity data, and also a Hysteresis correction element is equipped, which carries out a hysteresis correction by means of the control state and the steering angle and determines a fourth torque signal, the target control torque being calculated at least by a signal from the second torque signal, the third torque signal or the fourth torque signal and by the first torque signal. Vehicle steering device according to Claim 9 , wherein the characteristic of the basic map and the hysteresis correction element is vehicle speed sensitive. Vehicle steering device according to Claim 9 or 10 , wherein the setpoint control torque generation component is further equipped with a phase compensation element upstream or downstream of the basic characteristic diagram element and performing a phase correction, and the second torque signal is determined via the basic characteristic diagram element and the phase compensation element through the steering angle and the vehicle speed.

Images