DE10329278A1 - Stabilizer, vehicle equipped with it and stabilization method - Google Patents

Abstract

The invention relates to a stabilization device (25) for vehicle dynamic stabilization of a vehicle (10), DOLLAR A - with default means (41) for determining a desired yaw rate signal (49) and with DOLLAR A - limiting means (45) for determining a maximum yaw rate of Vehicle (10) representing limit yaw rate signal (50) such that the vehicle (10) remains drivably stable in consideration of the maximum yaw rate and limiting the target yaw rate signal (49) to the limit yaw rate signal (50) if the value of the target yaw rate signal (49) exceeds the value of the limit yaw rate signal (50). It is proposed that the stabilization device (25) comprises actual value means (53) for providing a tilt angle signal (56) representing the current tilt angle of the vehicle (10), DOLLAR A - that the limiting means (45) comprise tilt angle means for determining the limit yaw rate signal (50 ) based on the Kippwinkelsignals (56) and DOLLAR A - that the stabilizing device (25) generating means (42) for generating a steering intervention signal and / or at least one brake intervention signal based on the limited target yaw rate signal (49).

Description

The The invention relates to a stabilizing device for driving dynamics Stabilization of a vehicle, with default means of identification a desired yaw rate signal and with limiting means for Determining a maximum yaw rate of the vehicle representing Limit yaw rate signal such that the vehicle taking into account the maximum Yaw rate remains stable, and for limiting the target yaw rate signal to the limit yaw rate signal when the value of the target yaw rate signal exceeds the value of the limit yaw rate signal. The invention further relates to a single-track or multi-lane vehicle having a Such stabilizing device and a method with the Operation of such a stabilizing device.

A Such stabilization device is for example related with the vehicle dynamics control of a vehicle, such as a Passenger car from the article "FDR-Die Fahrdynamikregelung von Bosch", ATZ Automobiltechnische Zeitschrift 96 (1994) 11, pages 674 to 689, author Anton van Zanten, Rainer Erhardt and Georg Pfaff. The regulatory concept of the known vehicle dynamics controller is based on the so-called single-track model, at the vehicle speed and a default steering angle, the driver prescribes on a steering handle, a target yaw rate calculated. However, if the target yaw rate is too high, the vehicle, for example, due to low adhesive properties the wheels or the like the desired one Curve track could not drive, becomes the target yaw rate limited by the vehicle dynamics controller. The interventions of the vehicle dynamics control on the brakes and / or the engine of the vehicle take place on the basis the limited target yaw rate. To determine the desired yaw rate are the specifications of the driver of the vehicle with respect to the Steering angle and the driving and braking torque, the estimated vehicle speed and the coefficient of friction of the wheels evaluated.

The Known stabilization device is primarily a spin prevent the vehicle. However, it is also problematic that the Vehicle tips over, possibly overturning.

It Therefore, the object of the invention is a stabilizing device or to improve a method of the type mentioned in the introduction, that a risk of tipping the vehicle is reduced.

to solution the task is in the stabilizing device of the beginning It is intended that they be actual value means for the provision a tilt angle signal representing the current tilt angle of the vehicle in that the limiting means comprises tilt angle means for detection the limit yaw rate signal on the basis of the tilt angle signal and that they are generating means for generating a steering intervention signal and / or at least one Brake intervention signal based on the limited target yaw rate signal having. In a corresponding manner, an inventive vehicle and a method according to the invention according to the technical Teaching another independent Claim designed.

Of the Tilt angle, sometimes referred to as roll angle describes the Drezirk steering of the vehicle about its longitudinal axis. By consideration the tilt angle in the determination of the target yaw rate signal, the maximum allowed is, is a tilting or even overturning prevents the vehicle. The generators are For example, a yaw rate regulation. The steering intervention signal For example, controls a steering actuator for steering the wheels of a Axis on. With the aid of the brake intervention signal or several brake intervention signals brake actuators are activated. Preferably, the stabilization device a so-called steer-by-wire control. The stabilization device However, it can also be part of a vehicle dynamics controller of the vehicle form.

advantageous Embodiments of the invention will become apparent from the dependent claims and from the description.

Conveniently, the stabilization device additionally takes into account the current float angle of the vehicle. The slip angle is the angle between the vehicle's longitudinal axis and the vehicle speed vector. The float angle signal, which indicates the slip angle of the Vehicle is provided by the appropriately designed actual value means. The limiting means expediently contain float angle means for determining a second, limit-dependent limit yaw rate signal. The limiting means limit the value of the target yaw rate to the value of the yaw rate or yaw rate depending on which of the two yaw rates is less.

The Tilt angle signal may include the current tilt angle of the vehicle. Possible but is also that the tilt angle signal contains values, off where the tilt angle can be determined. In principle the same applies for the Floating angle signal, specifically the current slip angle of the Vehicle may contain. But it is also possible that it contains values where the vehicle swimming angle can be determined, for example including the vehicle lateral speed and vehicle longitudinal speed.

at A selection procedure has proved to be advantageous for the limitation means proved: the limiting means select as input to the generating means the target yaw rate signal, if its value is the value of the (first), tilt angle dependent Does not exceed limit yaw rate signal and otherwise the limit yaw rate signal, ie the maximum value of the yaw rate, the for the driving stability the vehicle is necessary. If the limiting means in addition also the second limit yaw rate signal, which depends on the slip angle of the vehicle is available choose the limiting means e.g. the smallest amount of yaw rate signal in terms of absolute value as input yaw rate signal for the generating means, for example the yaw rate control, off.

At This point should be noted: The one used above Term yaw rate signal is associated with the Desired yaw rate signal and the limit yaw rate signal uses. That the yaw rate signal is a signal representing a default value and whichever what made the selection, either the desired yaw rate signal or the limit yaw rate signal. Will of yaw rate signals spoken, so it is target yaw rate signals or limit yaw rate signals. The meaning presented here the two terms yaw rate signal or yaw rate signals should also be for their subsequent mention apply.

The Specifying agents are expediently based on at least one reference model of the vehicle. It can For example, a substantially real image of the vehicle act. But it is also possible that a desired behavior of the vehicle, for example, a sporting or comfortable desire behavior is selected as a reference model. In an expedient embodiment the invention are such desire models by a driver of Vehicle selectable. A reference model is e.g. from one or more differential equations, which describe the behavior of the vehicle.

The Actual value contain expediently Measuring means and / or estimating means. The measuring means are, for example, the vehicle sensors, e.g. Speed sensors, a yaw rate sensor, lateral acceleration sensors or similar. The estimation means preferably contain an observer. The observer is expediently not line ar. For example, it is the observer around a so-called Kalman filter.

The Actual value means accordingly represent real and / or estimated actual values ready. These actual values expediently form input values for the limiting means and include, for example, the tilt angle signal and / or the float angle signal. It is understood that such an observer is also an integral part can form the limiting means.

Conveniently, the actual value means are directly connected to the generation means. Advantageously, the actual value means provide input values for the generation means ready. It is also appropriate that the generation means provide input values for the actual value means.

Advantageously, the yaw rate signals are rotational direction dependent. For example, a negative value of a yaw rate signal represents a left turn and a positive value a right turn of the vehicle about its vehicle vertical axis. In a corresponding manner, the limiting means are designed to limit the nominal yaw rate signal in absolute terms. For example, in such a constellation, the tilt angle means and the slip angle means each provide a positive and a negative maximum limit yaw rate value. The lower and upper limits may be included in the first, tilt angle dependent and the second, bucket angle dependent limit yaw rate signals, respectively. The same applies mutatis mutandis to that of the default means he witnessed desired yaw rate signal.

The Stabilizing device according to the invention is expediently designed so that the vehicle under consideration the maximum yaw rate does not overturn. Accordingly, the Limiting means for determining the avoidance of vehicle rollover required limit yaw rate signals designed.

The Agent of the stabilizing device according to the invention can be executed in hardware and / or software. Conveniently, contains the stabilization device program code, which is controlled by a control means, in particular a processor, a driving stability control and / or a Steering control of the vehicle is executable. In the steering control For example, it is the control of a steer-by-wire system.

Preferably becomes the stabilizing device according to the invention used in multi-lane vehicles, such as passenger cars or commercial vehicles. The stabilization device may also be used single-track vehicles, such as motorcycles are used.

advantageously, becomes the target yaw rate signal in response to a default steering angle signal and a quantity representing the vehicle speed. The determination can be made with the help of a mathematical model, the For example, the Ackermann relationship is based, done.

following the invention with reference to an embodiment with reference closer to the drawing explained.

The FIG. 1 shows a vehicle according to the invention with a stabilizing device according to the invention.

A vehicle 10 For example, a passenger car with an internal combustion engine, not shown, has a front axle 11 with steerable wheels 12 . 13 and a rear axle 14 with non-steerable wheels 15 . 16 on. At the wheels 12 . 13 . 15 . 16 are brakes 17 . 18 . 19 . 20 for braking the respective wheel 11 . 12 . 15 . 16 as well as speed sensors 21 to 24 for detecting the respective wheel speed of the wheel 11 . 12 . 15 . 16 arranged. The brake 17 to 20 are schematically represented by arrows, by a stabilizing device 25 by means of brake intervention signals 26 to 29 controllable. The speed sensors 21 to 24 send the stabilization device 25 Speed signals 30 to 33 indicating the respective speed of the wheel 12 . 13 . 15 . 16 represent.

At a steering wheel 35 or any other steering handle may be a driver 36 a directional desire δ _H , the steering angle sensor 37 recorded, pretend. The steering angle sensor 37 generates a Vorgabelenkwinkelsignal 38 and transmits this to the stabilization device 25 , The stabilization device 25 generates, inter alia, taking into account the Vorgabelenkwinkelsignals 38 a steering intervention signal 39 and transmits the steering intervention signal 39 to a steering actuator assembly 40 which includes, for example, a servomotor or the like. The steering actuator assembly 40 steers the wheels 12 . 13 the front axle 11 , In principle, the stabilization device could 25 also a (not shown in the figure) steering intervention signal to one of the rear axle 14 send assigned (not shown) steering actuator, for example when the vehicle 10 a rear axle steering and / or a combined Vorderachs- or rear axle steering would have.

The stabilization device 25 In this case contains a so-called steer-by-wire control loop with default means 41 , a yaw rate regulation 42 , the generating means according to the invention forms, detection and output means 43 as well as an observer 44 , Furthermore, the total number is given by the reference numeral 45 designated limiting means present, the Kippwinkelmittel 46 , Floating angle means 47 as well as selection means 48 contain.

The stabilization device 25 For example, based on a vehicle model with three mechanical degrees of freedom. In addition to the slip angle β and the yaw angle ψ, the roll angle φ describes the current position of the vehicle 10 , From the set of momentum in the transverse direction and the spin set around the vertical axis and the longitudinal axis of the vehicle 10 can the following equations of motion (1) - (3) of the vehicle 10 be derived. In this case, variables are used to describe the driving state, which are transformed to a horizontal coordinate system.

In the equations (1) to (3), F _{s, V} + F _{s, H are} the lateral forces at the front and rear axles, and l _V and l _{H are} the center of gravity distances to the front and rear axles, respectively. The functions A and C describe nonlinear elements to be compensated by control technology. The function B corresponds approximately to the tilt angle-dependent reciprocal of the yaw moment of inertia. The function D corresponds approximately to the tilt angle-dependent quotient of the center of gravity and the roll moment of inertia.

With vehicles steerable at the front axle, the lateral force can be changed directly at the front. On the lateral force of the rear axle can be influenced by means of a brake engagement and / or a rear axle steering. Otherwise, the lateral force will be aft due to vehicle, tire and ambient parameters. The exemplified control approach relates to a front axle steering with an optional single-wheel braking intervention, for example by means of the brake intervention signals 26 to 29 , The present draft of yaw rate regulation 42 or the tilt angle means 46 expediently takes place with methods of non-linear control technology, for example with a Lyapunov function.

In the stabilization device 25 For example, the Lyapunov function V is as follows:

For the stability of the entire system, it is required that the function V is positive semidefinite and its time derivative is negative definite. It follows: V ≥ 0, V. <0 (5)

If the equations of motion (1) to (3) are used in the Lyapunov function (4), yaw rate control can be used 42 A repayment law is set up which compensates for the non-linear shares and stabilizes them with linear shares. This results in the following formula:

From the lateral force on the front axle F _SV can the yaw rate control 42 the steering intervention signal 39 , which contains a wheel steering angle, generate.

Analogous to the lateral force on the front axle F _SV , the Ljapunov function (4) can also be used for a desired yaw rate ψ. _To be determined at which the entire system by a tilt angle φ stably settles. The following formula (7) forms the basis for the tilt angle means 45 , which can also be referred to as Kippwinkelbegrenzungsreglung.

In this case, the coefficients λ _1, λ _2, λ _3, which determine the control dynamics, to the stability of the system suitably selected positive definite.

The stabilization device 25 is designed in the present case, that they the rolling / tilting movement of the vehicle 10 only when there is a risk of tipping or overturning of the vehicle 10 limited. The function of the slip angle means 47 , which can be referred to in the present case as Schwimmwinkelbegrenzungsregelung remains through the use of Kippwinkelmittel 46 and the selection means 48 unaffected. Simplified, you can say that the slip angle means 47 one Spin, the Kippwinkelmit tel 46 a tilting of the vehicle 10 in cooperation with the selection means 48 prevent. The selection means 48 In the process, a limiting function is used, which is explained in more detail below.

The default means 41 form based on the default steering angle signal 38 and a quantity representing the vehicle speed, a target yaw rate signal 49 , The quantity representing the vehicle speed is, for example, in a driving state signal to be described later 56 contain. As a rule, this setpoint yaw rate signal forms 49 the input for the yaw rate control 42 , However, not in every driving situation of the vehicle 10 the steering request of the driver 36 be implemented in the desired manner. The desired yaw rate signal 49 is from the limiting means 45 monitored and, if necessary, limited to a limit yaw rate signal. In the present case, the tilt angle means 46 a first limit yaw rate signal 50 and the slip angle means 47 a second limit yaw rate signal 51 , which is the current float velocity of the vehicle 10 depends on the selection means 48 ready. The selection means 48 choose the desired yaw rate signal 49 when it is smaller in magnitude than the limit yaw rate signals 50 . 51 , Otherwise choose the selection means 48 the lower absolute limit yaw rate signal 50 or 51 out.

The yaw rate signals 49 to 51 are present direction of rotation dependent, that is, they are for example provided with a sign. This applies to both the desired yaw rate signal 49 as well as for the limit yaw rate signals 50 and 51 , Accordingly, the boundary yaw rate signals are included 50 . 51 one upper and one lower limit each. One could also speak of a limit yaw rate at a right turn or a limit yaw rate at a left turn made by the tilt angle means and the slip angle means, respectively 46 . 47 be defined in each case. The yaw rate regulation 42 generates output signals 52 for example, the steering intervention signal 39 can contain. The output signals 52 are from the recording and output means 43 captured and to the actuators of the vehicle 10 for example, the brakes 17 to 20 transmitted. The acquisition output means 43 give, for example, the brake intervention signals 26 to 29 off and capture the speed signals 30 to 33 ,

The detection means 43 as well as the observer 44 form components of actual value agents 53 , The actual value means 53 measure and estimate system states of the vehicle 10 where they are, for example, the speed signals 30 to 33 for determining the transverse and longitudinal speed of the vehicle 10 evaluate. Non-measurable system values, but for example from the tilt angle means 46 Be required by the observer 44 determined, so to speak estimated, which one can call accordingly also as an estimating means.

The Observer 44 contains, for example, a Kalman filter and estimates, for example, based on the steering angle, the vehicle longitudinal speed, the lateral acceleration and a yaw rate, the detection means 43 in the context of a signal 57 to the observer, eg, a float angle, a tilt angle, a tilt angle velocity, or the like of the vehicle 10 , In principle, however, could also be the suspension travel on the wheels 12 . 13 . 15 . 16 until Abhe ben determine one of the wheels, so that tilt angle and Kippwinkelgeschwindigkeit could be determined as measured variables.

The current yaw rate of the vehicle 10 determines a yaw rate sensor 55 and transmits them as part of an actual yaw rate signal 54 to the stabilization device 25 ,

The Observer 44 sends a driving condition signal 56 to the default means 41 as well as the slip angle means 47 and the tilt angle means 46 , The driving condition signal 56 contains, for example, for the Kippwinkelmittel 46 the current tilt angle and / or the current tilt angle speed of the vehicle 10 , For the slip angle means 47 are in the driving condition signal 56 For example, the Schwimmwinkel- and / or the Schwimmwinkelgeschwindigkeit and / or the vehicle longitudinal speed and the vehicle lateral speed of the vehicle 10 contain. The driving condition signal 56 contains eg a tilt angle signal and a float angle signal. The in the driving condition signal 56 The vehicle longitudinal speed, which represents a quantity representing the vehicle speed, becomes the default means 41 for determining the desired yaw rate signal 49 fed.

The yaw rate regulation 42 as well as the observer 44 are also suitably directly connected with each other. This optional embodiment of the stabilization device 25 is therefore drawn in dashed lines. The Observer 44 transmits the driving condition signal 56 the yaw rate regulation 42 , In the opposite direction transmitted the yaw rate control 42 their output signals 52 So the Vorgabegrö ßen for the Fahrzeugaktuatorik, the observer 44 ,

It is understood that in the driving condition signal 56 whose contents are the actual value means 53 determine and / or estimate, also other signals may be included, for example, the pitch and / or the bank of the road on which the vehicle 10 emotional. At the vehicle 10 For example, it is also possible to provide a so-called Correvit sensor, which determines the vehicle lateral velocity and vehicle longitudinal speed or alternatively the float angle of the vehicle 10 can determine.

The used in the present description terms yaw rate and yaw rate are synonymous.

Claims (13)

Stabilization device for driving-dynamic stabilization of a vehicle ( 10 ), - with default means ( 41 ) for determining a desired yaw rate signal ( 49 ) and with - limiting means ( 45 ) for determining a maximum yaw rate of the vehicle ( 10 ) representing limit yaw rate signal ( 50 ) such that the vehicle ( 10 ) remains stable under consideration of the maximum yaw rate, and for limiting the target yaw rate signal ( 49 ) to the limit yaw rate signal ( 50 ), when the value of the desired yaw rate signal ( 49 ) the value of the limit yaw rate signal ( 50 ), characterized in that it is an actual value means ( 53 ) for providing a current tilt angle of the vehicle ( 10 ) representing tilt angle signal ( 56 ), - that the limiting means ( 45 ) Tilt angle means ( 46 ) for determining the limit yaw rate signal ( 50 ) based on the tilt angle signal ( 56 ), and - that they are generating agents ( 42 ) for generating a steering intervention signal and / or at least one brake intervention signal on the basis of the limited desired yaw rate signal (US Pat. 49 ) having. Stabilizing device according to claim 1, characterized in that the limiting means ( 45 ) for selecting the desired yaw rate signal ( 49 ) and the limit yaw rate signal ( 50 ) as an input signal for the generation means ( 42 ) are configured, wherein the desired yaw rate signal ( 49 ) is selected if its value is the value of the limit yaw rate signal ( 50 ), and otherwise the limit yaw rate signal ( 50 ) is selected. Stabilizing device according to claim 1 or 2, characterized in that the actual value means ( 53 ) for providing a current slip angle of the vehicle ( 10 ) are configured such that the limiting means ( 45 ) Float angle means ( 47 ) for determining a second limit yaw rate signal ( 51 ) based on the float angle signal, and that the limiting means ( 45 ) for limiting the desired yaw rate signal ( 49 ) to the value of the first limit yaw rate signal provided by the tilt angle means ( 50 ) or the second limit yaw rate signal ( 51 ) are configured when the value of the desired yaw rate signal ( 49 ) the value of the first or the second limit yaw rate signal ( 50 . 51 ) exceeds. Stabilizing device according to claim 3, characterized in that the limiting means ( 45 ) for selecting the desired yaw rate signal ( 49 ) and the first or the second limit yaw rate signal ( 50 . 51 ) as an input signal for the generation means ( 42 ), wherein the yaw rate signal having the lowest value is selected as the input yaw rate signal. Stabilizing device according to one of the preceding claims, characterized in that the presetting means ( 41 ) on at least one reference model of the vehicle ( 10 ). Stabilizing device according to one of the preceding claims, characterized in that the yaw rate signals ( 49 - 51 ) are dependent on the direction of rotation. Stabilizing device according to one of the preceding claims, characterized in that the actual value means ( 53 ) Measuring means ( 43 ) and / or estimating means ( 44 ) contain. Stabilization device according to claim 3, characterized in that the estimation means ( 44 ) contain an observer. Stabilizing device according to one of the preceding claims, characterized in that the actual value means ( 53 ), in particular the estimation means ( 44 ) the actual value means ( 53 ), directly with the generation means ( 42 ), the actual value means ( 53 ) Input values for the generation means ( 42 ) and / or the generation means ( 42 ) Input values for the actual value means ( 53 ) provide. Stabilizing device according to one of the preceding claims, characterized in that the limiting means ( 45 ) for determining the limit yaw rate signals ( 50 ) are configured such that the vehicle ( 10 ), taking into account the maximum yaw rate does not overturn. Stabilization device according to one of the preceding claims, characterized in that it comprises program code which is controlled by a control means, in particular a processor, a driving stability control and / or a steering control of the vehicle ( 10 ) is executable. Single-track or multi-lane vehicle ( 10 ) with at least one stabilizing device ( 25 ) according to one of the preceding claims, with actual value means ( 53 ) and / or sensors for generating a roll rate signal and a default steering angle signal and with a by the stabilization device ( 25 ) controllable Lenkaktoranordnung ( 40 ) for steering one or more wheels of an axle of the vehicle ( 10 ). Method for driving-dynamic stabilization of a vehicle ( 10 ) comprising the steps of: - determining a desired yaw rate signal ( 49 ), - determination of a maximum yaw rate of the vehicle ( 10 ) representing limit yaw rate signal ( 50 ) such that the vehicle ( 10 ) remains stable under consideration of the maximum yaw rate, - limitation of the desired yaw rate signal ( 49 ) to the value of the limit yaw rate signal ( 50 ), when the value of the desired yaw rate signal ( 49 ) the value of the limit yaw rate signal ( 50 ), characterized by - determining a current tilt angle of the vehicle ( 10 ) representing tilt angle signal ( 56 ), - determination of the limit yaw rate signal ( 50 ) based on the tilt angle signal ( 56 ), - Generating a steering intervention signal and / or at least one brake intervention signal on the basis of the limited desired yaw rate signal ( 49 ).