DE102010055373A1 - Method for controlling longitudinal dynamics of motor car to adjust target speed of motor car at idle travel, involves determining target acceleration depending on weighting factor for lowering sensitivity of controlling process - Google Patents

Abstract

The method involves determining a driving state parameter (Zf), which characterizes a driving status of a motor car (100). A target acceleration of the car is determined depending on the driving state parameter and an environmental parameter i.e. object position- and status data vector (Zo) so as to control longitudinal dynamics of the car depending on the target acceleration by an engine control unit and a brake control unit. The target acceleration is additionally determined depending on a weighting factor for lowering sensitivity of controlling process in less critical situations. An independent claim is also included for a motor car comprising a control device for controlling longitudinal dynamics.

Description

The invention relates to a method for controlling a longitudinal dynamics of a motor vehicle according to the preamble of claim 1 and a motor vehicle in which the method is used.

Methods for controlling a longitudinal dynamics of a motor vehicle are known. Corresponding methods and / or devices are also known as speed control systems and / or distance control systems. It is possible to set a target speed of the motor vehicle when driving freely. In the case of a follow-up run, it is possible to maintain or set a desired distance to a preceding object. Required actuating interventions can take place by means of a torque control of a drive unit, for example an internal combustion engine and / or by means of a brake device for introducing a braking torque. For corresponding control actions, energy consumption occurs during acceleration processes and wear of the controlled braking device during braking processes. From the DE 42 09 047 C1 A method for controlling the distance between moving vehicles is known. The method is applicable regardless of a type of distance detection. It is divided in the course of a distance control by evaluating at least the own vehicle speed v ₂ and the steering angle β of the follower vehicle the driving situation in i classes, depending on the classified driving situation a control law R _i for the braking of the driving force selected from a set of i laws and Situationally dependent control law for the total drive force F _{a 'is} to be controlled with the target distance S _S , as the sum of i with speed range, at least edge-overlapping classification functions k _i weighted individual rule R _i formed.

The object of the invention is to enable improved control of the longitudinal dynamics of a motor vehicle, in particular to provide a safe and reliable and also fuel-saving cruise control system and / or distance control system, which in stationary and safe driving situations save the focus on fuel and which in dynamic and at risk connected driving situations focus on fast and safe control behavior.

The object is achieved in a method according to the preamble of claim 1, characterized in that the target acceleration is additionally determined as a function of a weighting factor for lowering a sensitivity of a control behavior in less critical situations for the motor vehicle. Advantageously, the weighting factor can be included in the determination of the setpoint acceleration in such a way that corresponding control interventions in situations less critical for the motor vehicle are less pronounced, in particular have a lower gain. In contrast, in critical situations, a quick and precise control intervention can advantageously be carried out, that is, a higher gain can be specified by means of the weighting factor.

In one embodiment of the method, a determination of the weighting factor in dependence on an actual acceleration and a speed control error is provided. Advantageously, the actual acceleration and the speed control error give a measure of the situation in which the motor vehicle is located. Advantageously, the weighting factor can be determined as a function of the situation.

In a further embodiment of the method, a determination of the weighting factor as a function of a distance control error and / or a relative speed to a preceding vehicle is provided in the following or distance control mode. In particular, in the distance control operation, the relative speed and the distance represent a measure of the situation in which the motor vehicle is located. Advantageously, the weighting factor can be determined as a function of the situation.

In a further embodiment of the method, multiplying control parameters by the weighting factor is provided for determining the desired acceleration. The desired acceleration in the sense of a reference variable can advantageously serve as the input variable of a corresponding acceleration control unit of the motor vehicle. Advantageously, by influencing the desired acceleration by multiplying the control parameters by the weighting factor, a loop gain or control gain of a corresponding control loop for controlling the longitudinal dynamics of the motor vehicle can be influenced or adjusted.

In a further embodiment of the method, it is provided to determine the weighting factor as a characteristic curve which, by a zero position of the actual acceleration and / or the speed control error and / or the relative speed and / or the distance control error, has a trough-shaped course, in particular a two-sided ramp-shaped course, having. Advantageously, at relatively low actual accelerations and / or a low speed control error and / or at a low relative speed and / or with a small distance control error, a comparatively uncritical situation can be concluded. This is the case in the region of the zero position in which the characteristic has a low value. For increasing actual accelerations and / or speed control errors and / or Relative speeds and / or distance control error, the characteristic increases, which is associated with an increase in the weighting factor and, associated with an increase in the gain of the corresponding control loop. Advantageously, in a stationary and / or steady state and / or at comparatively low accelerations, a very gentle, fuel-saving and / or comfort-oriented control and / or control of the longitudinal dynamics of the motor vehicle can take place.

In a further embodiment of the method, an asymmetrical determination of the weighting factor is provided. By asymmetrically determining the weighting factor, it can be understood that the characteristic curve around the zero position of the actual acceleration and / or the speed control error and / or distance control error and / or the relative speed has an asymmetrical course. This can be used, for example, to the effect that in order to initiate accelerating interventions higher control deviations are required than for the initiation of delaying interventions. In principle, it is advantageous to classify a required deceleration of the motor vehicle as more critical since, for example, in a subsequent control mode, this is associated with the risk of colliding with the preceding object. Advantageously, it can be ensured by means of the asymmetrical course that, in the case of a critical approach to the preceding object, a correspondingly hard regulation or controller parameterization is performed more quickly than in the opposite, uncritical case, namely when the preceding object moves away from the vehicle. Advantageously, very gentle, in particular fuel-saving and / or comfort-oriented response to removal of the preceding object, while responding to an imminent collision with the highest possible safety, so fast and precise control intervention.

The object is also solved in a motor vehicle with a device for controlling a longitudinal dynamics of the motor vehicle, designed, set up and / or designed to carry out a method described above. This results in the advantages described above.

Further advantages, features and details will become apparent from the following description in which - where appropriate, with reference to the drawings - at least one embodiment is described in detail. Described and / or illustrated features form the subject of the invention, or independently of the claims, either alone or in any meaningful combination, and in particular may additionally be the subject of one or more separate applications. The same, similar and / or functionally identical parts are provided with the same reference numerals. Show it:

1 a schematic view of a motor vehicle with a device for controlling a longitudinal dynamics of the motor vehicle, the motor vehicle follows a preceding object distance controlled;

2 a block diagram of a Abstandsregeltempomateinheit including upstream and downstream control and / or measuring elements of in 1 shown motor vehicle;

3 a detailed block diagram of a controller adjustment unit and a speed control unit of in 1 shown block diagram;

4 a further detailed diagram of the controller adjustment unit and a distance control unit of in 2 shown block diagram;

5 a detailed block diagram of an ECO zone determination unit of in 3 shown block diagram; and

6 a detailed block diagram of a logic unit of in 3 shown block diagram.

1 shows a schematic view of a vehicle 100 that is an object 101 follows, for example, also a vehicle. The car 100 has a pitch control unit 5 on. By means of the adaptive cruise control unit 5 is the motor vehicle 100 Able to automatically drive the object in a speed and / or acceleration controlled state 101 to follow. Further, the pitch control speed unit is 5 designed to be an actual speed v _{ist of} the motor vehicle 100 set in dependence on a target speed, if in front of the motor vehicle 100 no object 101 located.

The input variables are the adaptive cruise control unit 5 an object position and state data vector Z _O , a vector with driving state data Z _{f '} and a vector with environment data Z _U. The vector Z _U with environmental data can be effected by means of vehicle-specific sensor units and / or in communication with further units, in particular via a data infrastructure cloud C, for example based on map data and / or satellite-based navigation.

2 shows a block diagram of in 1 shown distance control speed unit 5 of the motor vehicle 100 , To generate the object position and state data vector Z _{0 '} is an object detection unit 1 intended. To generate the vector Z _f with the driving condition data a driving condition detection unit 2 intended. For detecting and / or determining the vector Z _U with the environmental data is an environment detection unit 12 provided, wherein the environment detection unit 12 especially card- and satellite-based.

For the operation of the adaptive cruise control unit 5 is an operating and display unit 3 intended. This communicates with a controller adaptation unit 4 and exchanges display data S _a and operator data S _b . The vectors Z _f , Z _U and Z _O go as input variables in the controller adaptation unit 4 one. In addition, these go as input variables in a speed control unit 6 and a pitch control unit 7 the pitch control unit 5 one. The speed control unit 6 serves to influence the actual speed v _{ist of} the motor vehicle 100 and determines a target acceleration a _{Soll_VR} . For this purpose, the speed control unit 6 in particular a cruise control on.

The distance control unit 7 is used for controlled following of the object 101 and generates a desired acceleration a _{Soll_AR} , in particular as the output of a distance _controller . The desired accelerations a _{Soll_VR} and a _{Soll_AR} go as input to a desired acceleration _coordinator 8th A, which outputs a uniform target acceleration a _target as output. The desired acceleration a _{target of} the desired acceleration coordinator 8th goes as input to an acceleration control unit 9 one. The acceleration control unit 9 , which may be designed, for example, as a master controller for setting the target acceleration a _Soll , are a motor control unit 10 and a brake control unit 11 of the motor vehicle 100 downstream. The engine control unit 10 controls an engine, not shown, of the motor vehicle 100 and receives for this purpose a control signal U _m , for example, to set an engine torque and / or perform a speed step selection.

The brake control unit 11 controls a non-illustrated delay device, in particular brake, of the motor vehicle 100 and receives from the acceleration control unit 9 a control signal U _b .

According to the invention, the controller adaptation unit controls 4 additionally the speed control unit 6 as well as the distance control unit 7 , so that the target acceleration a _setpoint additionally in dependence on an output variable of the controller adaptation unit 4 is determined. The controller adaptation unit gives this 4 a weighting factor Gain_VR to the cruise control unit 6 , To the distance control unit 7 gives the regulator adjustment unit 4 a weighting factor Gain_AR. By means of the weighting factors Gain_VR and Gain_AR become the speed control unit 6 and the pitch control unit 7 Depending on the driving situation, it is parameterized dynamically.

3 shows a detail block diagram of the in 2 shown speed control unit 6 as well as regulator adaptation unit 4 ,

The speed control unit 6 as well as the regulator adaptation unit 4 received as input variables, a target speed v _{target of} the motor vehicle 100 , which can be specified by the driver on the cruise control lever as desired or set speed, for example, the actual speed v _{actual of} the motor vehicle 100 and an actual acceleration a _{actual of} the motor vehicle 100 , These quantities go into an ECO zone determination unit 41 for a vehicle speed controller of the cruise control unit 6 one. The ECO Zone Determination Unit 41 is a logic unit 42 the regulator adaptation unit 4 downstream. The logic unit 42 is used to activate and deactivate the weighting factor Gain_VR for the cruise control. Accordingly, the logic unit 42 as output variable, the weighting factor Gain_VR.

At a subtraction point of the cruise control unit 6 a setpoint / actual value comparison is made, wherein of the setpoint speed v _{desired of} the motor vehicle 100 the actual speed v _{ist of} the motor vehicle 100 is deducted. The output variable of the subtraction point is a speed control _error v _err .

The speed control error v _err is calculated with a control parameter K _v for the speed control error v _err , in particular multiplied.

The target speed v _{desired of} the motor vehicle 100 goes into a determination unit 63 the speed control unit 6 one. The determination unit 63 is used for an internal target acceleration determination and accordingly has an internal target acceleration a _{Soll_intern} as output variable. The internal target acceleration a _{Soll_intern} can, for example, according to the formula a _{set_intern} = d / dt (v _set ) and or a _{Soll_intern} = (v _Soll - v _Ist ) / T _v determinable, where T _{v has} a period of time, in particular a desired time behavior.

The internal target acceleration a _{Soll_intern} is at a further subtraction point with the actual Acceleration a _is the vehicle 100 offset, where a _is subtracted from a _{Soll_intern} . The output variable of the subtraction point is an acceleration control error a _err , which is offset, in particular multiplied, by a control parameter K _a for the acceleration control error a _err .

The control parameter K _v is a multiplication unit 61 downstream, which multiplies the output signal or the control parameter K _v , in particular multiplied by the speed control error v _err , by the weighting factor Gain_VR. The control parameter K _a is a further multiplication unit 62 downstream. The further multiplication unit 62 multiplies the control parameter K _a or the, with the acceleration control error a _err calculated, in particular multiplied, control parameters K _a also with the weighting factor Gain_VR of the logic unit 42 the regulator adaptation unit 4 , The multiplication units 61 and 62 is followed by an addition point, so that the output signals of the multiplication units 61 and 62 be added. As a result of the addition, the speed control unit provides 6 the desired acceleration a _{Soll_VR} .

4 shows a detail block diagram of the in 2 shown controller adjustment unit 4 and the distance control unit 7 , These receive as input variables an actual distance d _Ist between the in 1 shown motor vehicle 1 and the preceding object 101 , the object _velocity v _{obj of} the object 101 , the actual speed of the motor vehicle 100 , an object _acceleration a _{obj of} the object 101 and the actual acceleration a _{actual of} the motor vehicle 100 , These variables are input variables in an ECO zone determination unit 43 for the distance control unit 7 or a distance controller. The ECO Zone Determination Unit 43 the regulator adaptation unit 4 is an activation and deactivation logic unit 44 downstream, which outputs as output signal the weighting factor Gain_AR for the acceleration controller for controller parameterization.

The object speed v _obj and the actual speed v _Ist become at a subtraction point relative to a relative velocity v _rel between the motor vehicle 100 and the object 101 charged. The relative velocity v _rel is calculated at a further subtraction point with a desired relative velocity v _{rel, setpoint} for the relative velocity v _rel . The result is a relative speed _{control error} v _{rel_err} . The target relative velocity v _{rel, Soll} is determined by means of a differentiation unit 72 calculated from a desired distance d _setpoint . The desired distance d _desired is determined by means of a desired distance determination unit 71 determined. The desired distance determination unit 71 has as input the actual speed v _Ist and determines the desired distance d _set , by means of the differentiating unit 72 to the desired relative speed v _{rel, desired} between the motor vehicle 100 and the object 101 is charged. The setpoint relative speed v _{rel, setpoint also} serves as the input variable of a further differentiating unit 73 from which a desired relative acceleration a _{rel, desired} for a relative acceleration a _rel between the motor vehicle 100 and the object 101 determined. The relative acceleration a _rel is determined by means of a further subtraction point, which subtracts the actual acceleration a _actual from the object acceleration a _obj .

The means of the desired distance determination unit 71 calculated desired distance d _desired is subtracted from the actual distance d _actual at a further subtraction point, as a result of which a distance control error d _{err is} determined.

The relative acceleration a _rel determined as a function of the object acceleration a _obj and the actual acceleration a _{actual is} determined by means of a further subtraction point with that by means of the differentiation unit 73 determined target relative acceleration is calculated, wherein the target relative acceleration a _{rel, target is} subtracted from the relative acceleration three. As a result, the subtraction point provides a relative acceleration error.

The distance control unit 7 has a total of three control parameters K _d , K _vrel and _Celel . The control parameter K _d is calculated with the distance control error d _err , in particular multiplied. The control parameter K _vrel is offset with the relative speed control _error v _{rel_err} , in particular multiplied. The control parameter K _arel is offset with the relative acceleration _error a _{rel_err} , in particular multiplied.

In addition, the distance control unit 7 a _{Vorsteuerungsparameter} K _{a_ff} on. The _{precontrol parameter} K _{a_ff} is offset with the object _acceleration a _obj , in particular multiplied.

The control parameters K _d , K _vrel , K _arel and the pilot control parameter K _{a_ff} the distance control unit 7 is each a multiplication unit 74 . 75 . 76 . 77 connected to the respective parameter with the output of the activation and deactivation logic unit 44 the regulator adaptation unit 4 , namely multiply the weighting factor Gain_AR. The multiplication units 74 . 75 . 76 . 77 is an adder downstream of all the outputs of the multiplication units 74 . 75 . 76 . 77 to the output of the pitch control unit 7 , namely the target acceleration a _{Soll_AR} added.

5 shows a detail block diagram of the in 3 represented ECO zone determination unit 41 , This receives as input variables, as well as in 3 can be seen, the target speed v _target , the actual speed v _actual and the actual acceleration a _actual . At a subtraction point, the actual speed v _actual is subtracted from the setpoint speed, whereby the speed control _error v _{err is} calculated as the output variable. The speed control _error v _err goes together with the actual speed v _Ist in a division unit 4100 which outputs as output variable a velocity control error v _n normalized to the actual velocity v _Ist .

By means of a characteristic parameter unit 4130 a weighting factor minimum value G1_VR_min can be determined. The normalized speed control error v _n and the weighting factor minimum value G1_VR_min act on a characteristic curve 4120 for the determination of the weighting factor G1_VR. The characteristic 4120 has a trough-shaped course, more precisely a bilaterally limited ramp-shaped course, wherein a plateau with the height of the weighting factor minimum value G1_VR_min is present around a zero position of the normalized speed control error v _n , to which two ramp-shaped ascents, to the right and to the left, join in a each to minus ∞ and plus ∞ directed plateau with a value of 1, connect.

An application of the characteristic 4120 the normalized speed control error v _n gives as the output variable a weighting factor G1_VR from the characteristic curve 4120 ,

The actual acceleration a _actual becomes a characteristic curve 4150 applied to the weighting of the acceleration _error a _err . The result is the characteristic curve 4150 a weighting factor G2_VR. The characteristic 4150 can by means of a weighting factor minimum value G2_VR_min a characteristic parameter unit 4160 be parameterized, with a low plateau of the characteristic 4150 has the height of the weighting factor minimum value G2_VR_min. According to the invention is the characteristic 4150 asymmetric, wherein for a negative actual accelerations a _is a steeper and / or earlier increase of the two-sided ramp course is provided as for positive actual accelerations a _actual . This offers the advantage that braking, which in principle indicates a critical driving situation, is acknowledged with a tighter control behavior. The output curve is the characteristic curve 4150 the weighting factor G2_VR.

The characteristic 4150 can by means of a characteristic parameter unit 4140 be parameterized. The characteristic parameter unit 4140 provides as output a positive maximum acceleration a _{pos_max} , a positive minimum _acceleration a _{pos_min} , a negative maximum acceleration a _{neg_max} , a negative minimum acceleration a _{neg_min} which are the limits of the ramp- _{like slopes of} the characteristic curve 4150 to mark.

The characteristic 4120 can by means of a characteristic parameter unit 4110 be parameterized. This provides as outputs a maximum positive normalized speed control _error v _{n_pos_max} , a minimum positive normalized speed control _error v _{n_pos_min} , a maximum negative normalized speed control _error v _{n_neg_max} , a minimum negative normalized speed control _error v _{n_neg_min} , the normalized maximum and minimum speed control _errors being the limits of the ramp-like slopes of the curve 4120 establish.

The output variables of the characteristic parameter unit 4110 , the characteristic parameter unit 4140 as well as the characteristics 4120 and 4150 go as input into a vectoring unit 4151 one. This forms from this a vector X _VR as output, which is the logic unit 42 to activate and deactivate the controller adaptation unit 4 as input.

6 shows a detailed block diagram of the logic unit 42 for activation and deactivation.

The logic unit receives as input 42 the vector X _VR .

The vector X _VR goes as input to a signal selector unit 4220 one. The signal selector unit 4220 gives as output the weighting factor minimum value G1_VR_min and the weighting factor minimum value G2_VR_min to a minimum formation unit 4210 out. The minimum education unit 4210 gives as output a weighting factor GR_VR.

A constant value unit 4230 the logic unit 42 _Returns a minimum actual velocity v _{actual_min} .

A logic switch of the logic unit 42 receives as input quantities the weighting factor GR_VR, the vector X _VR , the minimum actual speed v _{Ist_min of} the constant _{value forming unit} 4230 and the constant value 1. The logic switch of the logic unit 42 can optionally switch an output to the constant value 1 or the weighting factor GR_VR, so that either the weighting factor for the vehicle speed controller Gain_VR is applied as output variable, as in FIG 6 represented, or alternatively the constant value 1.

For the logic switch, the following activation condition can be used as the basis for activating the controller parameter reduction, that is to say applying or switching the weighting factor Gain_VR to an output: Gain_VR = GR_VR {if (v _n <v _{n_pos_min)} OR (v _n> v _{n_neg_max ')}} AND {(a _n <a _{n_pos_min)} OR (a _n> a _{n_neg_max)}} and otherwise Gain_VR = 1.

For deactivating the controller parameter reduction, ie applying the constant value 1 to the output of the logic switch of the logic unit 42 the following disabling condition can be defined as: Gain_VR = 1 if {(v _n> v _{n_pos_max)} OR (v _n <v _{n_neg_min)} OR (a _n> a _{n_pos_max)} OR (a _n <a _{n_neg_min)} OR _(v < v _{is_min} )} or otherwise Gain_VR = GR_VR.

Advantageously, in steady-state control operation, in speed control and / or in follow-up control, smoother control behavior can be achieved in quasi-stationary operation, which is closer to a human driver, more comfortable and / or requires less fuel.

It is provided, the object recognition unit 1 which z. B. based on a radar system and / or a Lidarsystem and / or a stereo video camera system with downstream image analysis at least the longitudinal and lateral position and state data, such as speed and / or acceleration, the motor vehicle 100 surrounding objects 101 , In particular, an exactly preceding vehicle relative to the own motor vehicle 100 and / or to a lane. In an advantageous embodiment, the distances and relative speeds as well as the accelerations of the motor vehicle 100 surrounding objects relative to the own motor vehicle 100 determined and all detected signals in the measurement vector Z _O summarized.

In addition, the driving condition detection unit 2 provided, which determines the actual driving state consisting of the actual driving speed v _actual , the actual acceleration a _actual and a steering angle δ and summarized in the measurement vector Z _f .

In addition, the environment detection unit 12 provided, which using maps from navigation systems, video image processing systems and vehicle to infrastructure-based systems, in particular a data infrastructure cloud C, the environment of the motor vehicle 100 recorded and especially slopes and gradients of a road ahead and all detected signals in the measurement vector Z _U summarized.

In addition, the pitch control unit is 5 provided that the actual driving speed v _Ist and an actual distance d _actual to the preceding object 101 regulates. This has the vehicle speed control unit 6 on, the one by a driver of the motor vehicle 100 specified desired speed controls. In addition, this has the distance control unit 7 on which a safe distance to the preceding object 101 regulates. In addition, this has the desired acceleration coordinator unit 8th on, which determines from the target acceleration a _{Soll_VR} the _follow -up _control and the target acceleration a _{target AR of} the _follow -up control, for example, by a minimum formation to be controlled target acceleration a _target . In addition, this has a subordinate acceleration control 9 on which the control signal U _m to the engine control unit 10 of the engine and a control signal U _b to a brake control unit 11 a braking device of the motor vehicle 100 supplies.

In addition, according to the invention, the controller adaptation unit 4 provided, which the weighting factors Gain_VR for the controller parameters of the follow-up control and the weighting factors Gain_AR to reduce the control parameters of the Abstandsregeltempomateninheit 5 supplies.

In addition, the operating and display unit 3 provided, which is the driver specified and / or predefinable desired speed v _target , the actual driving speed v _Ist and in particular information about whether the motor vehicle 100 is located in a fuel-saving control mode, also called ECO mode, indicating. In addition, the operating and display unit offers 3 an input option with which the fuel-saving control mode can be switched on and / or off.

Further, the motor actuator 10 , which adjusts the control signal U _m in the engine and the brake actuator 11 , which adjusts the control signal U _b in the braking device provided.

The aforementioned components are in 2 shown.

2 shows the controller parameter adjustment in the cruise control. In the controller adaptation, vehicle speed control parameters K _v , K _a via the weighting factor Gain_VR become advantageous in those driving situations in which fuel-saving and simultaneous safe driving is possible, so-called ECO zones, reduced. The ECO zone determination unit determines this 41 for the cruise control the driving situations in which fuel-saving driving speed rules is possible. Via an activation and deactivation logic 42 , which checks the permissibility of activation and / or deactivation, the weighting factor Gain_VR to the cruise control 6 transmitted. For approved driving situations, so-called ECO zones, in which fuel-saving driving is possible, the weighting factor Gain_VR assumes values less than 1. Otherwise, the weighting factor Gain_VR assumes the value 1.

4 shows the controller parameter adjustment in the distance control. In principle, the controller parameter _adaptation takes place in such a way that the distance controller parameters, so-called for both the feedback K _d , K _vrel , K _elel and for the _precontrol K _{a_ff} via a weighting factor Gain_AR in those driving situations in which fuel-saving and simultaneous safe driving is possible ECO zones are reduced. The ECO zone determination unit determines this 43 for the distance control the driving situations, so-called ECO zones, in which fuel-saving and simultaneous safe follow-up driving is possible. About the activation and deactivation logic 44 which checks the permissibility of activation and / or deactivation in the distance control mode, the weighting factor Gain_AR is applied to the distance control unit 7 transmitted. For approved driving situations, so-called ECO zones, in which fuel-efficient driving is possible, the weighting factor Gain_AR assumes values less than 1. Otherwise, the weighting factor Gain_AR assumes the value 1.

5 shows the ECO zone determination unit 41 for the cruise control. The ECO zone is exemplified by two characteristics 4120 and 4150 determined. The characteristic _parameters v _{n_pos_min} , v _{n_neg_max} and a _{pos_min} , a _{neg_max} form an inner tolerance _band , and the characteristic _parameters V _{n_pos_max} , v _{n_neg_min} and a _{pos_max} , a _{neg_min} form an outer tolerance _band for the velocity control _{error characteristic} with speed control _error v _n normalized to the actual driving speed as the input quantity and the weighting factor G1_VR as the output variable or for the vehicle acceleration characteristic curve with the actual acceleration a _actual as the input variable and the weighting factor G2_VR as the output variable. All signals are combined in the transfer vector X _VR and to the night-connected logic unit 42 forwarded for activation and deactivation.

6 shows the logic unit 42 for activating and deactivating the cruise control. It is advantageously provided that the activation of the reduction of the controller parameters takes place only when the system is in the inner ECO zone. This is the case when the system is simultaneously in each of the characteristic curves describing the ECO zone, ie in the example of the characteristic curve 4120 and the characteristic 4150 located within the inner tolerance bands. The deactivation of the reduction of the controller parameters takes place when the system is removed from the outer ECO zone, which is defined by the outer tolerance bands and a minimum travel speed. This is the case when the system is at least outside one of the characteristics describing the outer ECO zone 4120 and 4150 , the outer tolerance bands is or falls below a minimum travel speed. This can be done for example on the basis of the previously described logical conditions.

According to the presentation of the 5 It is also possible to define tolerance bands or characteristic curves for activation and deactivation for the distance control. Instead of a normalized speed control error v _n is for the distance control, for example, in the ECO zone determination unit 43 a on the actual velocity v _is normalized relative velocity errors v _{rel_n} as an input variable for a zone the ECO-descriptive characteristic determined. For the distance control, a further characteristic curve describing the ECO zone can additionally be used in an advantageous manner, which uses as an input variable a distance control _error d _{err_n} normalized to the actual speed v _actual or standardized time interval _error . The corresponding characteristic _parameters v _{rel_n_pos_min} , v _{rel_n_neg_max} and d _{err_n_pos_min} , d _{err_n_neg_max} correspondingly form an inner tolerance _band and the characteristic _parameters v _{rel_n_pos_max} , v _{rel_n_neg_min} and d _{err_n_pos_max} , d _{err_n_neg_min} form an outer tolerance _band for the relative velocity _{control error characteristic} with the normalized to the actual driving speed Relative speed _error v _{rel_n} as the input variable and the weighting factor G1_AR as the output variable or for the distance control error characteristic with the distance control _error d _{err_n} normalized to the actual driving speed as the input variable and the weighting factor G2_AR as the output variable. It is alternatively and / or additionally possible to use so-called criticality characteristics which initially have a predicted time until a collision of the motor vehicle 100 with the object 101 , which is also referred to as time to collision (TTC) to determine and then use as an input a reciprocal of the Time to Collision TTC.

LIST OF REFERENCE NUMBERS

100

motor vehicle

101

object

1

Object recognition unit

2

Driving condition detection unit

3

Operating and display unit

4

Regulators matching unit

5

Adaptive cruise control unit

6

Speed control unit

7

Distance control unit

8th

Target acceleration ordinator

9

Acceleration control unit

10

Engine control unit

11

Brake control unit

12

Environment detecting unit

41, 43

ECO-zone determining unit

42

logic unit

44

Activation and deactivation unit

61, 62

multiplication unit

63

determining unit

71

Target distance determination unit

72, 73

Differentiating unit

74, 75, 76, 77

multiplication unit

4100

Division unit

4120, 4150

curve

4110, 4130, 4140, 4160

Characteristic Parameters Unit

4151

Vector forming unit

4210

Minimum Education Unit

4220

signal selector

4230

Constant value generation unit

G1_VR_min, G2_VR_min

Minimum value-weighting factor

G1_VR, G2_VR

weighting factor

v _is

Is speed

v _{is_min}

Minimally actual speed

v _should

Target speed

v _err

Speed control error

v _obj

object speed

v _rel

relative speed

v _{rel, Soll}

Target relative speed

v _{rel_err}

Relative speed control error

_vn

normalized speed control error

v _{n_pos_max}

maximum positive normalized speed control error

v _{n_pos_min}

minimum positive normalized speed control error

v _{n_neg_max}

maximum negative normalized speed control error

v _{n_neg_min}

minimum negative normalized speed control error

K _v , K _a , K _d , K _vrel K _arel

control parameters

K _{a_ff}

Feedforward parameters

Z ₀

Object position and state data vector

Z _f

Vector with driving status data

Z _U

Vector with environmental data

C

Data infrastructure cloud

a _{Soll_VR} , a _{Soll_AR} , a _Soll

Target acceleration

a _{Soll_intern}

internal target acceleration

a _is

Actual acceleration

a _err

Acceleration control error

a _obj

object acceleration

a _rel

relative acceleration

a _{rel, Soll}

Target relative acceleration

a _{rel_err}

Relative acceleration error

a _{pos_max}

positive maximum acceleration

a _{pos_min}

positive minimum acceleration

a _{NEG_MAX}

negative maximum acceleration

a _{neg_min}

negative minimum acceleration

U _m

actuating signal

U _b

actuating signal

Gain_VR

Weighting factor (cruise control)

Gain_AR

Weighting factor (distance control)

d _is

Actual distance

d _target

Target distance

d _err

Distance control error

X _VR

vector

δ

steering angle

QUOTES INCLUDE IN THE DESCRIPTION

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Cited patent literature

• DE 4209047 C1 [0002]

Claims (7)

Method for controlling a longitudinal dynamics of a motor vehicle ( 100 ) comprising the steps of: - determining an environment of the motor vehicle ( 100 ) characterizing environmental quantity (Z ₀ , Z _n ) by means of an object recognition unit ( 1 ), - determining a driving state of the motor vehicle ( 100 ) characteristic driving state variable (Z _f ) by means of a driving condition detection unit ( 2 ), - determining a desired acceleration (a _desired ) of the motor vehicle ( 100 ) as a function of the driving state variable (Z _f ) and the environmental variable (Z ₀ , Z _n ), - regulation of the longitudinal dynamics of the motor vehicle ( 100 ) as a function of the desired acceleration (a _desired ) by means of a motor control unit ( 10 ) and a brake control unit ( 11 ), characterized in that - the target acceleration (a _target ) is additionally determined as a function of a weighting factor (Gain_VR, Gain_AR) for lowering a sensitivity of the method in less critical situations for the motor vehicle. Method according to the preceding claim, characterized in that the weighting factor (Gain_VR, Gain_AR) is determined as a function of an actual acceleration (a _actual ) and a speed control error (V _err ). Method according to one of the preceding claims, characterized in that the weighting factor (Gain_VR, Gain_AR) is determined as a function of a relative speed (v _rel ) and a distance control error (d _err ). Method according to one of the preceding claims, characterized in that the determination of the desired acceleration (a _soll) on the multiplication of control parameters (K _d, K _{v rel,} K _arel, K _v, K _a) and / or pilot control parameters (K _aff) with the weighting factor (Gain_VR, Gain_AR). Method according to one of the preceding claims, characterized in that the weighting factor (Gain_VR, Gain_AR) is used as a characteristic curve ( 4120 . 4150 ) is determined, which by a zero position of the actual acceleration (a _actual ) and / or the speed control _error (v _err ) and / or the relative speed (v _rel ) and / or the distance control error (d _err ) a trough-shaped course, in particular a two-sided ramp-shaped course, having. A method according to claim 5, characterized in that the weighting factor (Gain_VR, Gain_AR) is determined such that it has an asymmetrical course with respect to the zero position of the actual acceleration (a _actual ) and / or the speed control _error (v _err ) and / or the relative speed (v _rel ) and / or the distance control error (d _err ). Motor vehicle ( 100 ) with a device for controlling a longitudinal dynamics, wherein the device is set up for the execution of a method according to one of the preceding claims, designed and / or constructed.

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