FR2828444A1 - Cruise control system for vehicle with regulation of distance and acceleration, comprises determination of regulating variables for engine and braking system from threshold value of acceleration - Google Patents

Abstract

A diagram (KF) enables a wheel couple (Mr) to be determined from a drive pedal value (PWG) and this is received by a coordinator of the propulsion chain (TSKO). The coordinator also receives an acceleration instruction (Asol) from the regulator (ACCR) which uses a longitudinal vehicle model to determine the engine torque (Mmt) for the engine (MT), the wheel torque (Mrd) for the transmission (GT) and the braking torque (Mbr) for the brakes (BR). Independent claims are also included for the following: A coordinator of the chain of propulsion. A cruise control system which uses a propulsion chain coordinator.

Description

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 The present invention relates to an adaptive pipe regulating system, also referred to as ACC (Adaptive Cruise Control) or ADR (Automatische Distanz Regelung) and an interface distance-acceleration control or acc-acceleration interface intended to apply in the ACC system.

 Traditional driving control systems control the speed of the vehicle at the level predefined by the driver. However, a problem arises when the vehicle is too close to the vehicle in front of it and a minimum safe distance must be observed.

 In the subsequent stages of development of these systems, the creation of adaptive driving control systems made it possible to interact at different levels with the previous vehicle. A common objective of adaptive driving control systems is to take into account an object on the road, the previous vehicle for example, and to implement measures intended on the one hand to respect the safety distance predefined by the driver and on the other hand to maintain the preset speed.

 DE-A-197 55 963 discloses a generic adaptive steering control system automatically adjusting the speed to that preselected by the driver and reducing it when crossing the minimum distance with the previous vehicle. The distance from the previous vehicle is then measured by means of a suitable device such as a radar system or a lidar system.

 Figure 5 shows the structure of the propulsion chain currently used by Volkswagen AG on certain models including the Dl and Colorado for example. The driver's wish is determined to be the MMT motor torque from a KF characteristic diagram

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comprising the number of revolutions N and a value representative of the position of the pedal PWG. The motor control MTST acts as a coordinator of the propulsion chain and realizes the motor torque Mm desired by the driver directly on the motor MT through the corresponding regulating variables. The control of the GTST gearbox is informed by the value of the PWG of the wish of the driver and therefore the wish of traction and this value is then transmitted to the GT gearbox via a switching program. The value of the PWG is the decisive variable for the GTST gearbox switching program, parallel to the number of revolutions N of the MT motor and the vehicle speed.

In the ACC (ACC) operation, the ACCR ACCR regulator's desire to intervene is also formulated according to the motor torque MM. The ACCR regulator integrated in the ACC system has a device for regulating the intervals between the vehicles and a device for regulating the speed. As part of this system integrated in the operation of the ACC system, decelerations can also be performed, the desired deceleration is transmitted via the desired brake pressure PBR of the BRST brake control or a brake amplifier active (not shown). The brakes BR are then set to this desired pressure PBR. The braking pressures PBR relating to a corresponding deceleration are determined by applications and distributed in the characteristic diagrams (not shown). The engine torque MMT is delivered to the gearbox GT, which converts the engine torque MMT into corresponding wheel pairs MR.

 The structure described has significant disadvantages in practice, in particular in the function-

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 the ACC system, as Figure 6 explains in detail. A known adaptive driving control system and its connection with the propulsion chain are shown schematically in FIG. 6, which chain comprises an ACC regulator and a motor control as described with reference to FIG. 5.

valeurs d'entrée la distance désirée dsoll par rapport au véhicule précédent, la distance réelle disi mesurée par le régulateur ACC par rapport au véhicule précédent, la vitesse entrée désirée vs,,,, du véhicule en lui-même et la vitesse réelle Visi du véhicule en lui-même. La vitesse relative par rapport au véhicule précédent, c'est-à-dire la vitesse résultant de différentes mesures de distance successives peut également être prise en compte. Avec la valeur du rapport de transmission reçue par la boîte de vitesse, s'établit un couple moteur correspondant au couple de roue additionnel requis. Ce couple moteur désiré M est transmis au dispositif de commande du moteur par l'intermédiaire du bus CAN comme étant la grandeur de consigne du régulateur ACC. Par ailleurs, une pression de freinage PBR qui est transmise au système de freinage ou à l'amplificateur de freinage est calculée le cas échéant. Le PWG (Capteur de la valeur de pédale) étant égal à zéro dans le cadre du fonctionnement du système ACC, une valeur virtuelle de la pédale d'accélérateur est transmise à la boîte de vitesse GT par l'intermédiaire d'un diagramme inverse du comportement en marche, valeur qui est relative au souhait du conducteur correspondant et qui est transmise au programme de commutation SP. Le principal inconvénient se situe précisément à ce niveau : l'inversion During acceleration processes typical of the operation of the ACC system, acceleration as constant as possible can be sought, for example 1 m / s. To achieve this acceleration, the ACC regulator internally calculates a model of longitudinal dynamics of the vehicle, using as

input values the desired distance dsoll relative to the previous vehicle, the actual distance disi measured by the ACC regulator relative to the previous vehicle, the desired entry speed vs ,,,, of the vehicle itself and the actual speed Visi of the vehicle itself. The relative speed with respect to the preceding vehicle, that is to say the speed resulting from different successive distance measurements can also be taken into account. With the value of the transmission ratio received by the gearbox, a motor torque corresponding to the additional wheel torque required is established. This desired motor torque M is transmitted to the engine control device via the CAN bus as the setpoint of the regulator ACC. Furthermore, a braking pressure PBR which is transmitted to the brake system or to the brake amplifier is calculated where appropriate. The PWG (Pedal Value Sensor) being equal to zero as part of the ACC system operation, a virtual value of the accelerator pedal is transmitted to the GT gearbox via an inverse diagram of the accelerator pedal. running behavior, which is relative to the wish of the corresponding driver and is transmitted to the switching program SP. The main disadvantage lies precisely at this level: inversion

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 The characteristic of the running behavior pattern causes very high gradients in the characteristic diagram of the behavior on the approach to full load, so that small positive changes in the motor torque lead to significant changes in the virtual PWG. The gearbox then re-triggers as a result of the switching process, for example the passage from the 4th to the 5th, by which the engine torque has to rise, a downshifting process. The consequences for the driver result in extremely awkward pendulum switching, which can occur several times during prolonged acceleration processes.

 Another drawback related to this structure is that during a prolonged acceleration process, constant acceleration values are difficult to achieve, since the acceleration, which adapts to the desired engine torque of the ACC system and to the ratio The transmission chain of the current propulsion chain is not centrally regulated but is often a product of chance due to the fully autonomous switching strategy of the gearbox compared to the ACC regulator.

 The ACC controller application ultimately depends on engine and vehicle specific data. Therefore, each new combination engine, vehicle, sensor involves new applications and validations.

 Furthermore, it is known from DE-A-196 24 615, an ACC regulator distance control is known for a vehicle that has a unit regulating the distance from an object in front of the vehicle and a unit regulating the speed of the vehicle. The distance controlling unit then generates a desired acceleration as a function of distance and the speed controlling unit generates a desired acceleration as a function of speed. Both

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 accelerations are compared to each other and their minimum is brought internally to another unit which calculates the control variables for the engine and braking system, variables which are then routed to the engine control and the control of the engine. braking through the ACC system.

 The objective of the invention is therefore based on the development of an ACC-acceleration interface between an ACC regulator and the propulsion chain, the development of a propulsion chain coordinator with an ACC-acceleration interface and the development of an adaptive system of driving control, which make it possible to avoid the disadvantages mentioned above.

 This objective is achieved by a device for regulating the speed and distance of an adaptive system for regulating the driving of a vehicle, which determines the control variables necessary for the engine and the braking system of the vehicle from a set value of the acceleration as input data, characterized in that the device determines an additive wheel torque corresponding to the setpoint acceleration by using a longitudinal dynamic model of the vehicle.

 The invention also proposes a propulsion chain coordinator for controlling the propulsion chain of a vehicle, comprising the motor elements (MT), gearbox (GT) and braking system (BR), which determines for the elements of the propulsion chain the corresponding regulating variables, namely engine torque (MMR), wheel torque (MRD) and braking torque (MBR) or braking pressure (PBR), this coordinator being characterized in that it comprises a device for regulating speed and distance as defined above with a longitudinal dynamic model.

 The invention also proposes an adaptive system for regulating the driving of a vehicle, equipped with a propulsion chain coordinator and an ACC regulator

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 which determines an output variable for the vehicle setpoint acceleration from the predetermined control variants that are the speed and the setpoint distance and the measured input variables that are the actual speed and distance. The output variable thus developed is transmitted to the coordinator of the propulsion chain.

 In the speed and distance control device, according to the invention, belonging to an adaptive speed control system of a vehicle, which device determines the control variables required for the engine and the braking system from a input variable represented by the desired acceleration of the vehicle, an additional wheel torque corresponding to the desired acceleration is determined from the desired acceleration using a vehicle longitudinal dynamics model.

 Preferably, the longitudinal acceleration of the vehicle is involved in the model of longitudinal dynamics of the vehicle, the longitudinal acceleration of the vehicle being able to be determined by means of a longitudinal acceleration module integrated in the vehicle optionally providing the following results .

 The model of the longitudinal dynamics of the vehicle notably offers the possibility of using influence variables relating to rolling friction, moments of rotational and translational inertia, air resistance and slope. of the way. The slope of the track can be calculated from the longitudinal acceleration of the vehicle and the acceleration determined by the speed of the vehicle.

 In a preferred manner, the device according to the invention, that is to say the ACC-acceleration interface, has a pilot control and a mixed integral proportional regulator. Moreover, the device may have a torque coordinator module, which converts the wheel torque

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 additive to a driving torque or a wheel braking torque depending on whether the value is positive or negative.

 The propulsion chain coordinator, according to the invention, for controlling the propulsion chain of a vehicle consisting of the engine, transmission and braking system elements and which elaborates for the elements of the chain the corresponding regulating variables relating to the torque motor, the wheel torque and the braking torque, contains the device explained above, where the coordinator is advantageously formed by a motor control device, where the output variables of the coordinator of the propulsion chain are a driving torque , a wheel torque and a braking pressure or a braking torque.

 The adaptive pipe control system according to the invention of a vehicle equipped with the propulsion chain coordinator described above also has an ACC regulator which determines from the predefined control variables relating to the set speed and to the vehicle's set distance and the measured input variables relating to the real speed and the actual distance of the vehicle, an output value corresponding to the desired acceleration of the vehicle and which transmits it to the propulsion chain coordinator or at the ACC interface.

 The setpoint acceleration of the ACC system is preferably transmitted to the propulsion chain coordinator via the CAN bus. The ACC system comprises a speed control module and a distance control module, where the speed control module produces a set speed acceleration as a function of the speed and the distance regulation module a setpoint acceleration depending on the speed. of distance, which are directed on a minimum trainer to determine the smallest acceleration. Moreover, this minimum determined by the minimum trainer from

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 the setpoint acceleration function of the setpoint speed and acceleration distance function can be subjected to filtering or clipping.

 The propulsion chain structure according to the invention avoids the disadvantages of the known structure mentioned above by decoupling the ACC system and the propulsion chain coordinator. An essential difference from the known structure lies in highlighting the ACC system as acceleration.

The application of the ACC system thus becomes largely independent of the vehicle parameters such as weight, air resistance, rolling friction, etc. while the extent of the software in the ACC system is limited to calculating the setpoint acceleration required for the purpose followed, namely finding and maintaining the desired speed.

 Another advantage is the greatly simplified application of the ACC system and the propulsion chain coordinator. Changes in the engine torque characteristic no longer interact with the ACC system and no longer need to be subjected to more demanding applications or validations.

 The ACC-acceleration interface is advantageously combined with a wheel torque-oriented switching strategy at the level of the control of the transmission. The necessary setpoint wheel torque is transmitted to the transmission and the latter determines from the traction diagram how fast this wheel torque is achievable by considering the characteristics of the engine. Incorrect switching is avoided.

Thus, the problem of commutes can be largely avoided by the new structure.

 A preferred embodiment of the invention is described in the following with the aid of the drawings.

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 Figure 1 shows the structure of the propulsion chain according to the invention in schematic representation; FIG. 2 shows the regulation circuit for the ACC system of a vehicle according to the invention in schematic representation; Figure 3 is an overview of the ACC acceleration interface; Figure 4 shows the ACC system used in the structure of the propulsion system according to the invention; Figure 5 shows a known structure of the propulsion chain; and Figure 6 illustrates a known control circuit for the operation of an ACC system of a vehicle.

 FIG. 1 shows a preferred embodiment of a propulsion chain structure provided with the adaptive system for regulating the pipe according to the invention.

A KF diagram is used to determine an MR wheel torque from the driver's wish expressed using the PWG pedal value sensor and to transmit it to a TSKO propulsion chain coordinator.

 In the operation of the ACC system, the ACCR regulator of the ACC system transmits an atoll setpoint acceleration to the TSKO propulsion chain coordinator.

The ACCR regulator application of the ACC system is therefore independent of the vehicle parameters, such as weight, air resistance, rolling friction, etc. and the range of software in the ACCR ACCR regulator is limited to calculating the atoll setpoint acceleration required to find or maintain the desired speed.

 The TSKO coordinator of the propulsion chain, which may consist of the engine control, determines the additional wheel torque required for the asoll setpoint acceleration by means of a vehicle longitudinal dynamics model. This wheel torque enters the

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 TSKO coordinator torque structure as setpoint. Henceforth, the TSKO coordinator of the propulsion chain thus determines each of the driving variables: the motor torque MMT for the motor MT, the torque MRD for the transmission GT or the command GTST of the transmission and the braking torque MBR for the BR brake system or BRST brake control.

 FIG. 2 shows the regulation circuit for the operation of the ACC system of a vehicle in accordance with the use of the adaptive speed control system according to the invention in a modified version without a wheel torque oriented switching strategy. The ACCR ACC regulator determines an asoll setpoint acceleration, which is transmitted to the BSS acceleration interface by means of a CAN bus; this determination is made from the input variables of the setpoint distance dsoii, with respect to a rolling object in front of, in particular a vehicle, actual measured distance digit, target speed Vsoll of the vehicle, preferably predefined by the driver and the speed Vist actual measured vehicle. The BSS acceleration interface, which is represented here independently of the TSKO coordinator of the propulsion chain for better understanding, calculates, using a vehicle longitudinal dynamics model, the additional torque of the MRD wheel required for the requested acceleration and the forward for further calculations to the TSKO coordinator. It calculates the torque control torque MMT for the MT motor and the desired brake pressure PBR for the braking system BR. Furthermore, a PWG value of a pedal position sensor is determined from the engine torque MMT by using an inverse diagram of the running behavior KFinv and is transmitted to a switching program SP of the control of the gearbox ( not shown), which selects the corresponding report. This UEB mechanism is retransmitted back to the coordinator of the propulsion chain.

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 Figure 3 illustrates the BSS interface of the ACC acceleration system, which includes an LBS longitudinal acceleration sensor, a BSR acceleration regulator, and a torque coordinator. The longitudinal acceleration sensor LBS determines the longitudinal acceleration aLg of the vehicle and makes it available to the acceleration regulator BSR. The BSR acceleration regulator, consisting of a pilot control and a mixed integral proportional regulator, calculates an additional MRD wheel torque corresponding to the required acceleration atoll by means of a vehicle longitudinal dynamics model considering the variables of the vehicle. influence on rolling friction, moments of translational and rotational inertia, air resistance and pavement slope recognition in the presence of an LBS longitudinal acceleration sensor . This wheel torque can accept both negative and positive values.

 This torque MRD wheel is then transferred to a torque coordinator MKO, which supports the conversion of the MRD wheel torque into a set torque motor MMT or, in the case of a pair of wheel MRD negative, into a corresponding wheel braking torque MBR. In addition, the torque coordinator MKO has a hysteresis, which prevents an alternation too frequent between the stop and the resumption of the thrust at the level of the push / pull. The torque coordinator is not necessarily a constituent part of the acceleration interface, but it can be realized within the propulsion chain coordinator, if the Acc-Acceleration interface and the propulsion chain coordinator are executed separately. .

 FIG. 4 shows in a diagrammatic form the ACCR regulator of the ACC system shown in FIGS. 1 and 2, which comprises a speed regulator GR and an AR distance regulator. The GR cruise control

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 calculates a setpoint acceleration av depending on the speed from the input variants of the setpoint speed Vsoii, which is preferably predetermined by the driver, the actual speed Vist and a limit speed VGr. The distance controller AR calculates a setpoint acc acceleration distance from the input variables actual speed Vist, relative velocity VRel between the vehicle and the object preceding it, actual distance dist between the vehicle and the object the preceding and the predefined set distance droll between the vehicle and the object preceding it.

The lower of the two accelerations is determined in a trainer of minimum MIN and emitted as setpoint acceleration after filtering as well as a limitation in an FT filter. The determination of the relative speed Vrel as well as the actual distance dist can be obtained using a radar or lidar system.

 For the explanation of Figures 5 and 6, reference should be made to the introductory part of this memo.

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LIST OF ABBREVIATIONS EMPLOYED

<Tb>
<tb> ACCR <SEP> Regulator <SEP> ACC <SEP>(<SEP> sensor)
<tb> distance / controller <SEP> of <SEP> speed)
<tb> KF <SEP> Chart <SEP> Characteristic <SEP> of <SEP> Behavior
<tb> in <SEP> works
<tb> KF <SEP> INV <SEP><SEP><SEP> inverse <SEP> chart of
<tb> behavior <SEP> in <SEP> works
<tb> PWG <SEP> Comparator <SEP> of <SEP> the <SEP> Pedal
<tb> N <SEP> Number <SEP> of <SEP> turns
<tb> MMT <SEP> Couple <SEP> engine
<tb> MR <SEP> Couple <SEP> of <SEP> the <SEP> wheel
<tb> PBR <SEP> Pressure <SEP> of <SEP> braking
<tb> MBR <SEP> Couple <SEP> of <SEP> braking
<tb> MT <SEP> Engine
<tb> GT <SEP><SEP> box of <SEP> speed
<tb> BR <SEP><SEP> System of <SEP> Braking
<tb> MTST <SEP><SEP> command of <SEP> engine
<tb> GTST <SEP><SEP> command of <SEP><SEP><SEP> box of <SEP> speed
<tb> BRST <SEP><SEP> command of <SEP> braking
<tb> droll <SEP> Distance <SEP> of <SEP> setpoint
<tb> dIst <SEP> Actual <SEP> Distance
<tb> VSoll <SEP> Speed <SEP> of <SEP> setpoint
<tb> VIst <SEP> Actual <SEP> Speed
<tb> VRel <SEP> Speed <SEP> relative
<tb> aSoll <SEP> Acceleration <SEP> of <SEP> setpoint
<tb> aLg <SEP> Longitudinal Acceleration <SEP>
<tb> Kfz <SEP> Vehicle
<tb> SP <SEP><SEP> Program of <SEP> Switching
<tb> UEB <SEP> Mechanism <SEP> of <SEP> transformation <SEP> of <SEP> speed <SEP> of
<tb> the <SEP> organ of <SEP> transmission
<tb> TSKO <SEP> Coordinator <SEP> of <SEP> The <SEP> Organ of <SEP> Transmission
<tb> SP <SEP><SEP> Program of <SEP> Switching
<tb> BSS <SEP> Interface <SEP> acceleration
<tb> LBS <SEP> Longitudinal <SEP> Acceleration <SEP> Sensor
<Tb>

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<Tb>
<tb> BSR <SEP> Acceleration Regulator <SEP>
<tb> MKO <SEP> Coordinator <SEP> of <SEP> couple
<tb> GR <SEP> Regulator <SEP> of <SEP> Speed
<tb> AR <SEP><SEP>Regulator><SEP> Distance
<tb> av <SEP> Acceleration <SEP> of <SEP> Setpoint <SEP><SEP> Function of <SEP>
<tb> speed
<tb> aD <SEP><SEP> Acceleration of <SEP> Setpoint <SEP><SEP> Function of <SEP>
<tb> distance
<tb> MIN <SEP> Trainer <SEP> of <SEP> minimum
<tb> FT <SEP> Filter <SEP> with <SEP> limitation
<Tb>

Claims (17)

1. Device for regulating the speed and distance of an adaptive system for regulating the driving of a vehicle, which determines the control variables necessary for the driving motor and the vehicle braking system from a set value of the acceleration as input data, characterized in that the device determines an additive wheel torque corresponding to the setpoint acceleration from it using a longitudinal dynamic model of the vehicle.  2. Device according to claim 1, characterized in that the longitudinal acceleration of the vehicle is part of the model of longitudinal dynamics of the vehicle.  3. Device according to claim 2, characterized in that the longitudinal acceleration of the vehicle is determined by means of a longitudinal acceleration module followed by a consecutive operating module.  4. Device according to any one of the preceding claims, characterized in that the model of longitudinal dynamics of the vehicle comprises the variables of influence relating to the rolling friction, to the moment of inertia of translation and rotation, to the resistance of the vehicle. air and the slope of the roadway.  5. Device according to claim 4, characterized in that the slope of the road is determined from the longitudinal acceleration of the vehicle and the acceleration determined from the speed of the vehicle.  6. Device according to one of the preceding claims, characterized in that the device comprises a pilot and a mixed integral proportional regulator.  7. Device according to any one of the preceding claims, characterized in that the device comprises a torque coordinator module (MKO), which converts the wheel torque (MRD), depending on whether the value is <Desc / Clms Page number 16> 8. Propulsion chain coordinator, intended to control the propulsion chain of a vehicle, comprising the drive motor (MT), gearbox (GT) and braking system (BR) elements, which determines for the elements of the propulsion chain the corresponding control variables engine torque (Mm), wheel torque (MRD) and braking torque (MBR) or braking pressure (PBR), characterized in that the propulsion chain coordinator (TSKO) comprises a device according to any one of the preceding claims  positive or negative, in a motor torque (MMR) or a braking torque (MBR) - Propulsion chain coordinator according to claim 8, characterized in that the propulsion chain coordinator (TSKO) is formed by a motor control device.  An adaptive vehicle control system having a propulsion chain coordinator (TSKO) according to claim 8 or 9 and an ACC system controller (ACCR) which determines an output variable. for the target acceleration (asoll) of the vehicle from the predetermined control variables of the target speed (Vsoll) and the vehicle setpoint (dsoll) and the measured input variables relating to the actual speed (Vist ) and the actual distance (dist) of the vehicle and transmits it to the propulsion chain coordinator (TSKO).  System according to Claim 10, characterized in that the acceleration target value is transmitted from the ACC system controller (ACCR) to the propulsion chain coordinator (TSKO) via a CAN bus.  System according to one of Claims 10 or 11, characterized in that the ACC system controller (ACCR) comprises a speed regulation module (GR) and a distance regulation module (AR). <Desc / Clms Page number 17>  13. System according to claim 12, characterized in that the speed regulation module (GR) forms a setpoint acceleration (av) as a function of the speed and the distance regulation module (AR) a setpoint acceleration ( ad) function of the distance which are both directed to a minimum (MIN) trainer for the development of the set acceleration (soll).  14. System according to claim 13, characterized in that the minimum determined by the minimum (MIN) trainer from the setpoint acceleration function of the speed (av) and the setpoint acceleration function of the distance ( ad) is subjected to filtering and clipping in a filter / limiter (FT).  15. System according to any one of claims 10 to 14, characterized in that the system further comprises a control of the gearbox (GTST) and a brake control (BRST).  System according to claim 15, characterized in that the control of the gearbox (GTST) comprises a switching program (SP), which selects the ratio from the setpoint wheel torque (MRD) prepared by the coordinator of propulsion chain (TSKO) considering the engine characteristic.  17. System according to claim 16, characterized in that the switching program (SP) of the gearbox control (GTST) determines the ratio by means of a traction force diagram.