DE102016215004B4 - Method for operating an electric servomotor, roll stabilizer device and vehicle - Google Patents

Abstract

Method for operating an electric servomotor (12), which uses a setpoint variable (MS) supplied to it to generate a torque (M) between two parts (10a, b) of a divided roll stabilizer (8) for a chassis (4) of a two-lane vehicle ( 2), in which, in a normal mode (BN): - a size controller (16) the target size (MS) for the servomotor (12) based on the size controller (16) supplied default variable (MV) between the two parts (10a, b) and a measured actual variable (MI) between the two parts (10a, b) generated, - the target size (MS) is supplied to the servomotor (12), characterized in that- is monitored whether the normal mode (BN) has an error (F), and- in the event of an error (F) in an error mode (BF): - an emergency size (MN) is determined, and- the servomotor (12) the emergency size (MN) is supplied in place of the desired value (MS), - in the event that the error (F) the size controller (16) and / or the actual G size (MI) concerns: - in error mode (BF) a size control (30) instead of the size controller (16) the target size (MS) based on the default size (MV) determined, where- the target size (MS) by the size control (30) by means of an inverse physical model (32) of the roll stabilizer (8) based on the default size (MV) is determined.

Description

The invention relates to an electric servomotor which generates a torque between two parts of a split roll stabilizer for a chassis of a two-lane vehicle.

Systems for regulating the roll behavior of two-lane motor vehicles are known in various embodiments. Their primary objective is to reduce the roll angle and, as a result, to increase ride comfort, driving safety and agility. The systems are roughly subdivided into passive, switchable, semi-active and active anti-roll bar systems, the present invention being related to the latter design in the form of an active anti-roll bar. While the opposing forces applied by a passive anti-roll bar result directly from the relative movements of the structure to the wheel, active systems allow the targeted application of counter-moments. Their control takes place, for example, as a function of the lateral acceleration and / or the roll angle of the motor vehicle. In addition to a reduced roll motion of the vehicle body can be achieved with an active split anti-roll bar, the two halves against each other, an improved self-steering behavior of the vehicle by a driving condition-dependent distribution of the stabilizer moments between the front and rear of the vehicle, and there are less copy effects in unilateral road bumps by a substantial decoupling of the stabilizer halves. In this case, a desired counter-torque mentioned above can be provided hydraulically or electromotively by the left and right stabilizer halves being rotated against each other by means of a suitable actuator or motor. The invention relates to systems with electric servomotor. An electromechanical or electromotive roll stabilization system is for example in the DE 10 2008 053 481 A1 described.

In the case of active and thus controllable systems, the possibilities of disturbances in the system must always be taken into account and a suitable reaction provided thereon. In electro-mechanical roll stabilization systems, therefore, a failsafe mode is desirable. It is conceivable, e.g. a higher-level fault, for example, in a control unit controlling the vertical dynamics and the lateral dynamics of the motor vehicle or in their communication with subsystems. d. H. could be present in a data bus system of the vehicle.

From the DE 10 2013 203 442 A1 a method is known in which an electric servomotor is controlled on a divided anti-roll bar in the chassis of a two-lane vehicle so that the anti-roll bar behaves like an undivided passive stabilizer by a base angle between the two stabilizer halves is kept active. In other words, in the roll stabilizer, the engine performs a zero position control in the event of a fault, whereby a passive stabilizer is imitated.

From the DE 10 2008 053 003 A1 a method for generating signals for influencing the movement of a controllable or controllable in his movements vehicle construction of a motor vehicle is known, wherein sensorically the movement of the vehicle body is determined, the sensor values determined corresponding sensor signals are supplied to a damper controller and the damper controller supplies at least one control signal to Actuation of actuators, in particular semi-active or active dampers, by means of which the movement of the vehicle body can be influenced. It is provided that in the event of failure of at least one sensor value required for determining the movement of the vehicle body, this sensor value is determined from the remaining available sensor values taking into account the instantaneous control request as a substitute value.

From the DE 100 47 414 A1 a method for controlling an air suspension for a rail vehicle with at least one car body is known, which is supported by air springs on at least one chassis, measured variables are absorbed by sensors and converted into corresponding measurement signals and the measurement signals are fed to an electrical control unit, which control valves for Electricity is achieved by reaching control targets in order to let in or out air in air springs, in which the heights and pressures of the air springs are included as measured variables, and the measurement signals are checked for errors and erroneous measured values are replaced by estimated measured values.

From the US 5,627,751 A a suspension for a land vehicle is known in which a plurality of wheel and hub assemblies are each connected via one of a plurality of actuators to the chassis of the vehicle. The operation of each actuator is controlled by an electronic or electrical processor. The processor operates in response to signals received from a plurality of sensors producing output signals indicative of the orientation of the chassis and forces on the chassis; eg, a yaw gyrometer, a lateral acceleration sensor, a longitudinal acceleration sensor, a steering angle sensor, a vehicle speed sensor, a load cell, a hub acceleration sensor, and LVITs. The processor detects the error of a Sensors and sensor failure detection operate in response to the remaining one or more of the sensors of the plurality of sensors.

From the DE 10 2013 2015 370 A1 a method for controlling a chassis stabilization arrangement for a vehicle is known which comprises an actuator and at least one operatively connected to the actuator stabilizer element, depending on the driving condition of the vehicle and / or load condition of the chassis stabilization on the one hand between an angular control of the stabilizer element or operatively connected to the stabilizer element drive element the actuator and a torque control of the stabilizer element or a drive element of the actuator operatively connected to the stabilizer element is switched on the other hand.

Object of the present invention is to respond to disturbances in and around a roll stabilizer with two parts and electric servomotor.

The object is achieved by a method according to claim 1 , Preferred or advantageous embodiments of the invention and other categories of invention will become apparent from the other claims, the following description and the accompanying drawings.

The method is a method for operating an electric servomotor. The electric servomotor generates a torque between two parts of a shared roll stabilizer on the basis of a target quantity supplied to it, in particular a desired torque. For the sake of clarity and readability, in the context of this description, without limiting the general validity or the patent claims, the "size" is generally described as "moment" in the embodiment. However, this is only representative of other "sizes" such as force, position or torsion, etc. If not the "target torque", but the target force, target engine position, target torsion, etc. supplied as a target size, occurs here in place of the "moment" a force / position / torsion, etc. The invention applies mutatis mutandis to these other cases. The roll stabilizer is one for a chassis of a two-lane vehicle.

In an error-free, i. regular or normal operation, the following happens:

A size controller, in particular a torque controller, generates the desired value for the servomotor based on a default torque (representative of the default value) and a measured actual torque (deputy for actual size). In addition to the above, it is once again mentioned that the "torque controller" is merely representative of "force / position / torsion controller", etc. The default torque refers to a torque or torque between the two parts of the roll stabilizer and is fed to the torque controller. In particular, the default torque is provided to the torque controller by means of a communication. The actual moment also refers to the moment between the two parts. The movements and moments in the roll stabilizer relate to a torsion axis of the roll stabilizer, about which the two parts are twistable against each other. That the default torque is provided by means of "communication" means that this is supplied in particular to the torque controller via a communication interface, for example, starting from a higher-level control unit via a corresponding signal line. So meant is any transmission of the default torque to the torque controller.

According to the method, the target torque is supplied to the servomotor.

"Measured" means that the actual moment, which currently exists between the two parts of the roll stabilizer, is determined in any way directly or indirectly. Alternatively, as explained above, e.g. the measurement of a force and the calculation of the force or the moment with the aid of the stiffness of a torsion bar and the measurement of a torsion angle of the torsion bar.

The same applies e.g. also for a speed of the servo motor, which is currently available.

According to the method, it is monitored whether the normal operation has an error. In the case of the occurrence or recognition of any corresponding error, an error operation is started according to the method. In this an emergency torque (deputy for emergency size) is determined and supplied to the servomotor the emergency torque instead of the target torque.

The invention is based on the idea that in the case of recognizing any error is no longer ensured that the target torque is determined correctly and thus the servomotor is operated as desired. The "target torque" is an engine torque, ie the output of the size regulator. It is therefore not, for example, the specification of the torque controller (default torque). For safety's sake, therefore, a substitute value for the target torque, namely an emergency torque, is at least partially determined independently of the above-described procedure according to normal operation, and this supplied to the servomotor as a default. So can critical driving situations in one Vehicle with a corresponding roll stabilizer can be avoided.

In a preferred embodiment, the case is considered that the error relates to the actual moment. In this case, in fault mode, a substitute torque (deputy for substitute variable) is determined for the actual torque and the torque controller is supplied with the substitute torque instead of the actual torque. Apart from this deviation, the procedure is otherwise the same as in normal operation in error mode. That is, it is equally determined a "target moment" according to the above procedure, which then represents the emergency moment. In this case, therefore, the emergency torque is determined from the replacement torque with the aid of the default torque and the torque controller. Only in the torque controller, the replacement torque is used instead of the actual torque. The determined "desired torque" thus represents the emergency torque and is supplied to the servomotor.

The error relates in particular to a failure of or a faulty measurement on a sensor for the actual torque, an error on a signal line via which the actual torque is transmitted to the torque controller, or an input on the torque controller, via which the actual torque of this is accepted, and so on.

Thus, according to this embodiment, the error-free components of the normal operation according to this are further used to perform the regular procedure almost identically, only substitute torque is used instead of the actual torque. Accordingly, high-quality emergency moments can be generated.

In a preferred variant of this embodiment, the replacement torque is determined on the basis of a physical model of the roll stabilizer. As a result, replacement moments can be generated or determined which usually approximate the measured actual moments, so that high-quality emergency moments are generated.

If the case is considered that the error relates to the torque controller and / or the actual torque, then in error mode, a torque control (deputy for size control) determines the setpoint value instead of the torque controller. This does this alone on the basis of the default moment without taking the actual moment further into account. The target size is thus determined only in a controlled manner alone from the default moment and no longer in a regulated manner additionally based on the actual moment. The torque controller is no longer used, but a corresponding torque control is used as a replacement. Otherwise - as described above - the "target torque" in the form of the emergency torque as determined in normal operation and fed to the servomotor. Although the emergency moment is no longer based on a regulated, but at least on a controlled size and is therefore still variable or situation-dependent adapted. Thus, a high quality emergency response is still provided.

In this case, the desired value is determined by the torque control using an inverse physical model of the roll stabilizer based on the default torque. The torque control thus forms the roll stabilizer in an inverse manner and thus generates high-quality setpoint variables on the basis of the supplied default moments. Even so, a high quality emergency response is ensured.

A preferred embodiment relates to the case that the error does not relate to an actual speed. This is especially the case when the setpoint for the torque controller (default torque) is faulty or breaks off a communication that is used to transmit the default torque to the torque controller or missing the setpoint for the torque control. In error mode, the emergency torque is determined based on a replacement instruction from the actual speed. The replacement rule is chosen so that the servomotor causes a damping operation of the roll stabilizer. Each (especially caused from the outside) rotation or torsion of the roll stabilizer is thus (in particular by the servo motor) opposed to an opposing moment, which is in particular smaller than the torque causing the torsion. This embodiment is suitable for almost any error cases, since only the actual speed is needed, especially for those who the default torque or the communication over which the default torque is provided concerns. This measure thus intervenes for errors in the communication to the rest of the vehicle and errors in the torque controller. According to this variant, an emergency torque is still provided even in the case of a serious system fault, in order to be able to specify an emergency torque for the servomotor, at least based on the replacement rule. At least the actual speed of the servomotor is thus included in the replacement rule, so that the replacement instruction is parameterized accordingly. Thus, an emergency torque dependent on the actual speed can be generated.

In a preferred variant of this embodiment, an emergency torque is determined in accordance with the replacement rule, which is opposite to an actual direction of rotation of the servomotor and is dependent on its actual speed. In particular, the direction of rotation is determined in such a way that it is checked whether the actual rotational speed has a positive (then a corresponding first rotational direction) or a negative value (then different rotational direction). Thus, can be achieved depending on the speed of effective and high-quality damping in the system.

In a preferred variant of this embodiment, the emergency torque is determined directly proportional to the actual speed. Thus, a high-quality emergency torque can be provided as a damping torque even with only intact actual speed.

The object of the invention is also achieved by a roll stabilizer device. This includes a roll stabilizer for a chassis of a two-lane vehicle, the roll stabilizer is divided into two parts. The roll stabilizer device includes a servomotor that is configured to generate a torque between the two parts according to a target amount (target torque). The device includes a size controller (torque controller) arranged to set a target size for the servo motor based on a preset amount (default torque) between the two parts and a measured actual size (actual torque) between the two parts to create. The roll stabilizer device contains a control and evaluation unit. This is set up to carry out the method according to the invention.

The roll stabilizer device and at least some of its embodiments as well as the respective advantages have already been explained analogously in connection with the method according to the invention. In particular, the control and evaluation unit contains a means for generating the replacement torque and / or a physical model of the roll stabilizer and / or torque control and / or an inverse physical model of the roll stabilizer and / or a means for implementing the replacement rule and / or a computing unit for Calculation of the directly proportional emergency torque from the actual speed.

The roll stabilizer device is thus equipped accordingly to be able to carry out all variants of the above-mentioned method.

The object of the invention is also achieved by a vehicle which is a two-lane vehicle and includes a chassis. The vehicle includes a roll stabilizer device according to the invention. The chassis of the vehicle contains the roll stabilizer of the roll stabilizer device. The vehicle and at least part of its embodiments and the respective advantages have been explained analogously already in connection with the roll stabilizer device according to the invention and the method according to the invention.

The invention is based on the following findings or considerations, in which context embodiments of the invention are also mentioned as the invention, which correspond to combinations of the abovementioned embodiments and / or optionally also include previously not mentioned embodiments.

The invention describes a fail-safe concept for an electromechanical roll stabilizer. The invention describes an alternative solution to that of DE 10 2013 203 442 A1 known solution. According to the invention, in a certain error case, a torque replacement value is regulated based on a model of the roll stabilizer. In the case of a lack of communication with the vehicle, a constant speed-dependent attenuation should be set. In the event of a failure of the torque sensor, critical driving situations can occur. To avoid this, a failure value of the torque sensor is set to a substitute value. This substitute value is generated in a physical model of the actuator.

On the other hand, if there is a failure of the communication to the higher-level control unit, the information of the moment to be set (default moment) is missing. A reasonable assumption can not be made here on the level of the actuator. In order to increase the stability of the vehicle, an attenuation at the front axle and / or the rear axle is set in this case of error. In this case, the servo motor requests a rotational speed proportional to its rotational speed that is proportional to its rotational speed. The servomotor thus acts as a torsional vibration damper.

• 1 ein Fahrzeug mit einer Wankstabilisatoreinrichtung im Normalbetrieb,
• 2 die Wankstabilisatoreinrichtung in einem Fehlerbetrieb,
• 3 die Wankstabilisatoreinrichtung in einem alternativen Fehlerbetrieb,
• 4 die Wankstabilisatoreinrichtung in einem weiteren alternativen Fehlerbetrieb.

Further features, effects and advantages of the invention will become apparent from the following description of a preferred embodiment of the invention and the accompanying figures. This shows in a schematic outline sketch:

• 1 a vehicle with a roll stabilizer device in normal operation,
• 2 the roll stabilizer device in a fault mode,
• 3 the roll stabilizer device in an alternative fault mode,
• 4 the roll stabilizer device in a further alternative fault operation.

1 shows strongly symbolizes a section of a two-lane vehicle 2 with a chassis 4 , The vehicle 2 contains a roll stabilizer device 6 with a roll stabilizer 8th where the landing gear 4 the roll stabilizer 8th contains. The roll stabilizer 8th is in two parts 10a . b divided and around a torsion axis 14 can be twisted against each other. The roll stabilizer device 6 contains a servomotor 12 , the torque in operation or when needed M around the torsion axis 14 between the two parts 10a . b generated. This happens in a normal mode BN the roll stabilizer device 6 according to specification of a desired torque MS , which is the servomotor 12 is supplied. The roll stabilizer device 6 contains a torque controller 16 , the set moment MS for the servomotor 12 based on a default moment MV and an actual moment MI generated. The default torque MV is by means of a here only symbolically indicated communication 18 to the torque controller 16 provided. Specifically, in the example, the default torque MV through to the vehicle 2 belonging, the roll stabilizer device 6 higher-level control 20 provided or to the torque controller 16 communicated. The default torque MV is a default value for the moment M that between the two parts 10a . b should work. The actual moment MI this is currently between the two parts 10a , b measured moment M , The example becomes the actual moment MI from a moment sensor 22 determined. The previously described procedure takes place in a normal mode BN instead, which is summarized as follows:

The servomotor 12 generates the torque M between the two parts 10a . b of the roll stabilizer 8th in the chassis 4 of the vehicle 2 based on the specification of the target torque MS , The torque controller 16 determines the target torque MS by means of communication 18 provided default torque MV and the measured actual moment MI , The target moment MS becomes the servomotor 12 fed.

The roll stabilizer device 6 also contains an in 1 only indicated control and evaluation 26 , which is adapted to carry out the method described below.

It is monitored whether in normal operation an error F is recognized. If such is detected, an error operation BF started and an emergency moment MN determined and the servomotor 12 the emergency moment MN instead of the setpoint torque MS fed. The mistake F can occur here in any component of the components and processes involved in normal operation and is in 1 represented by exemplary arrows only symbolically.

2 shows a first error operation BF the roll stabilizer device 6 in which the error F the actual moment MI concerns. For example, the moment sensor falls 22 or returns erroneous values and / or the transmission from the torque sensor 22 to the torque controller 16 is faulty. Both components are only indicated by dashed lines in order to indicate the potential defectiveness at least at one point of the dashed components. This solution can therefore be used for all errors that occur at any point in the dashed components. In error mode BF becomes a substitute moment ME for or instead of the actual moment MI determined and the torque controller 16 the replacement moment ME instead of the actual moment MI fed. The remaining components are also in error mode, but according to normal operation BN operated, so the emergency moment MN on the otherwise same way as the target moment MS is determined and output.

In the example, the replacement moment becomes ME based on a physical model 28 of the roll stabilizer 8th However, it could also be determined in any other way. The model 28 and the generation of the replacement torque ME is part of this or happens through the control and evaluation 26 , as indicated by dashed lines in the figure.

3 shows the roll stabilizer device 6 with an alternative mistake F that's the actual moment MI and / or the torque controller 16 concerns why these components are again shown in dashed lines. The dashes have the same meaning as above, ie stands for any error at least one point of the dashes. In error mode BF here becomes the emergency moment MN no longer using the torque controller 16 but with the help of torque control 30 determined. This happens on the basis of the default torque MV as in normal operation BN , Since it is a control instead of a control, is different from the normal operation BN a feedback in the form of the supply of the actual moment MI not necessary anymore. Otherwise, the emergency moment MN again the same as in normal operation BN determined. The torque control 30 contains an inverse physical model 32 of the roll stabilizer 8th , by means of or with the help of which the emergency moment MN from the default torque MV is determined. In this case, the torque control 30 and the inverse model 32 Components of the control and evaluation unit 26 (indicated by dashed lines).

4 shows another case where the error F almost all components of the roll stabilizer device 6 concerns the normal operation BN Exempt or error-free is only an actual speed DI or is this error-free available. The actual speed DI is the current speed of the servomotor 12 that is measured by this. The potentially faulty components are again shown in dashed lines. The dashes have the same meaning as above, ie stands for any error at least one point of the dashes. In error mode BF becomes the emergency moment MN by means of a replacement rule VE from the actual speed DI determined. The replacement rule VE is chosen so that the servomotor 12 a damping operation of the roll stabilizer 8th causes. That means, depending on the current roll stabilizer 8th measured actual actual speed DI generates the servomotor 12 a dampening opposite moment M ,

According to the replacement rule VE becomes an emergency moment MN determines that of an actual direction of rotation of the servomotor 12 is opposite and dependent on its actual speed DI is. The direction of rotation is based on the sign of the value of the actual speed DI determined. Positive values mean a certain direction of rotation, negative values mean the opposite direction of rotation. In particular, the emergency moment MN according to the formula MN = - k * DI as a substitute rule VE directly proportional to the actual speed DI with the proportionality factor k> 0.

LIST OF REFERENCE NUMBERS

2

vehicle

4

landing gear

6

Wankstabilisatoreinrichtung

8th

roll stabilizer

10a, b

part

12

servomotor

14

torsion

16

Torque controller (size controller)

18

communication

20

control

22

Moment sensor (size sensor)

26

Control and evaluation unit

28

model

30

Torque control (size control)

32

inverse model

M

torque

MS

Target torque (target size)

MV

Default moment (default size)

MI

Actual moment (actual size)

ME

Replacement moment (replacement size)

MN

Emergency moment (emergency size)

DI

Actual speed

BN

normal operation

BF

error operation

F

error

VE

replacement provision

Claims (8)

Method for operating an electric servomotor (12), which uses a setpoint variable (MS) supplied to it to generate a torque (M) between two parts (10a, b) of a divided roll stabilizer (8) for a chassis (4) of a two-lane vehicle ( 2), in which, in a normal mode (BN): - a size controller (16) the target size (MS) for the servomotor (12) based on the size controller (16) supplied default variable (MV) between the two parts (10a, b) and a measured actual variable (MI) between the two parts (10a, b) generated, - the target size (MS) is supplied to the servomotor (12), characterized in that - is monitored whether the normal mode (BN) has an error (F), and - in the event of an error (F) in an error mode (BF): - an emergency size (MN) is determined, and - the servomotor (12) the emergency size (MN) is supplied in place of the desired size (MS), - in the event that the error (F) the size controller (16) and / or d The actual quantity (MI) relates to: - in error mode (BF), a size controller (30) instead of the size controller (16) determines the target size (MS) on the basis of the default size (MV), where - the target size (MS) is determined by the size control (30) by means of an inverse physical model (32) of the roll stabilizer (8) on the basis of the default size (MV). Method according to Claim 1 , characterized in that - in the event that the error (F) relates to the actual size (MI): - in error mode (BF), a substitute size (ME) for the actual size (MI) is determined, and the size regulator (16) is supplied with the substitute size (ME) instead of the actual size (MI). Method according to Claim 2 , characterized in that the substitute quantity (ME) is determined on the basis of a physical model (28) of the roll stabilizer (8). Method according to one of the preceding claims, characterized in that in the event that the error (F) does not affect an actual speed (DI): in fault mode (BF) the emergency size (MN) based on a replacement rule (VE) the actual speed (DI) is determined, the substitute rule (VE) is selected so that the servo motor (12) causes a damping operation of the roll stabilizer (8). A method according to claim 4, characterized in that according to the substitute rule (VE) an emergency quantity (MN) is determined, which is opposite to an actual direction of rotation of the servomotor (12) and dependent on its actual speed (DI). Method according to Claim 5 , characterized in that the emergency size (MN) is determined directly proportional to the actual speed (DI). Roll stabilizer device (6), - with a roll stabilizer (8) for a chassis (4) of a two-lane vehicle (2), which is divided into two parts (10a, b), - with a servomotor (12) which is adapted to to generate a torque (M) between the two parts (10a, b) in accordance with a desired quantity (MS) fed to it, with a size regulator (16) arranged to set the set value (MS) for the servomotor (12) on the basis of a the size regulator (16) supplied default size (MV) between the two parts (10a, b) and a measured actual size (MI) between the two parts (10a, b) to produce, characterized in that the roll stabilizer device (6) contains a control and evaluation unit (26) which is set up to carry out a method according to one of the Claims 1 to 8th perform. Vehicle (2), which is a two-lane vehicle, with a chassis (4), characterized in that the vehicle (2) includes a roll stabilizer device (6) according to claim 9, wherein the chassis (4) of the vehicle (2) the roll stabilizer (8) of the roll stabilizer device (6).

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