Classifications

• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B60—VEHICLES IN GENERAL
  • B60T—VEHICLE BRAKE CONTROL SYSTEMS OR PARTS THEREOF; BRAKE CONTROL SYSTEMS OR PARTS THEREOF, IN GENERAL; ARRANGEMENT OF BRAKING ELEMENTS ON VEHICLES IN GENERAL; PORTABLE DEVICES FOR PREVENTING UNWANTED MOVEMENT OF VEHICLES; VEHICLE MODIFICATIONS TO FACILITATE COOLING OF BRAKES
  • B60T8/00—Arrangements for adjusting wheel-braking force to meet varying vehicular or ground-surface conditions, e.g. limiting or varying distribution of braking force
  • B60T8/17—Using electrical or electronic regulation means to control braking
  • B60T8/1701—Braking or traction control means specially adapted for particular types of vehicles
  • B60T8/1708—Braking or traction control means specially adapted for particular types of vehicles for lorries or tractor-trailer combinations
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B60—VEHICLES IN GENERAL
  • B60T—VEHICLE BRAKE CONTROL SYSTEMS OR PARTS THEREOF; BRAKE CONTROL SYSTEMS OR PARTS THEREOF, IN GENERAL; ARRANGEMENT OF BRAKING ELEMENTS ON VEHICLES IN GENERAL; PORTABLE DEVICES FOR PREVENTING UNWANTED MOVEMENT OF VEHICLES; VEHICLE MODIFICATIONS TO FACILITATE COOLING OF BRAKES
  • B60T8/00—Arrangements for adjusting wheel-braking force to meet varying vehicular or ground-surface conditions, e.g. limiting or varying distribution of braking force
  • B60T8/17—Using electrical or electronic regulation means to control braking
  • B60T8/1755—Brake regulation specially adapted to control the stability of the vehicle, e.g. taking into account yaw rate or transverse acceleration in a curve
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B62—LAND VEHICLES FOR TRAVELLING OTHERWISE THAN ON RAILS
  • B62D—MOTOR VEHICLES; TRAILERS
  • B62D13/00—Steering specially adapted for trailers
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B62—LAND VEHICLES FOR TRAVELLING OTHERWISE THAN ON RAILS
  • B62D—MOTOR VEHICLES; TRAILERS
  • B62D15/00—Steering not otherwise provided for
  • B62D15/02—Steering position indicators ; Steering position determination; Steering aids
  • B62D15/025—Active steering aids, e.g. helping the driver by actively influencing the steering system after environment evaluation
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B62—LAND VEHICLES FOR TRAVELLING OTHERWISE THAN ON RAILS
  • B62D—MOTOR VEHICLES; TRAILERS
  • B62D6/00—Arrangements for automatically controlling steering depending on driving conditions sensed and responded to, e.g. control circuits
  • B62D6/002—Arrangements for automatically controlling steering depending on driving conditions sensed and responded to, e.g. control circuits computing target steering angles for front or rear wheels
  • B62D6/003—Arrangements for automatically controlling steering depending on driving conditions sensed and responded to, e.g. control circuits computing target steering angles for front or rear wheels in order to control vehicle yaw movement, i.e. around a vertical axis
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B60—VEHICLES IN GENERAL
  • B60T—VEHICLE BRAKE CONTROL SYSTEMS OR PARTS THEREOF; BRAKE CONTROL SYSTEMS OR PARTS THEREOF, IN GENERAL; ARRANGEMENT OF BRAKING ELEMENTS ON VEHICLES IN GENERAL; PORTABLE DEVICES FOR PREVENTING UNWANTED MOVEMENT OF VEHICLES; VEHICLE MODIFICATIONS TO FACILITATE COOLING OF BRAKES
  • B60T2230/00—Monitoring, detecting special vehicle behaviour; Counteracting thereof
  • B60T2230/06—Tractor-trailer swaying
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B60—VEHICLES IN GENERAL
  • B60T—VEHICLE BRAKE CONTROL SYSTEMS OR PARTS THEREOF; BRAKE CONTROL SYSTEMS OR PARTS THEREOF, IN GENERAL; ARRANGEMENT OF BRAKING ELEMENTS ON VEHICLES IN GENERAL; PORTABLE DEVICES FOR PREVENTING UNWANTED MOVEMENT OF VEHICLES; VEHICLE MODIFICATIONS TO FACILITATE COOLING OF BRAKES
  • B60T2260/00—Interaction of vehicle brake system with other systems
  • B60T2260/02—Active Steering, Steer-by-Wire

Definitions

• the invention relates to a method for stabilizing a vehicle combination consisting of a towing vehicle and a trailer or semitrailer.
• the invention further relates to a vehicle dynamics control system for stabilizing a vehicle combination consisting of a towing vehicle and a trailer or semitrailer, which is suitable for carrying out the method.
• Vehicle combinations which consist of a towing vehicle and a trailer or semi-trailer, have an unstable driving behavior above a certain limit speed. Above the limit speed, rolling movements of the trailer or semitrailer occur whose amplitudes increase. Especially when driving on the highway vehicle teams often reach the speed limit, so that rolling movements of the trailer are caused, leading to some serious accidents. The reason for this is that average-trained drivers can not generally sufficiently stabilize a lurching team, since steering movements designed for stabilization are not in the required phase relationship with the rolling movements, so that they may even be intensified.
• vehicle dynamics control systems which robustly detect the yawing vibrations of the vehicle and stabilize the vehicle body by driver-independent braking interventions.
• the speed of the vehicle combination is reduced below the limit speed.
• the yawing moment is in particular determined from a control deviation between a detected actual yaw rate and a reference yaw rate, which is usually calculated on the basis of a vehicle model, in particular from a steering angle signal representing the driver's direction request.
• the steering angle signal entering into the calculation of the reference yaw rate can have signal oscillations which can be traced back to the trailer's rolling movements.
• the signal oscillations may be caused by steering movements performed by the driver or the steering actuator to compensate for the yawing vibrations of the trailer. This can lead to impairments of the vehicle dynamics control and in particular to erroneous interventions of the control system.
• this object is achieved by a method having the features of patent claim 1 and by a device having the features of patent claim 15.
• a vehicle dynamics control system for stabilizing a vehicle combination consisting of a towing vehicle and a trailer or a semi-trailer.
• the vehicle dynamics control system comprises:
• a sensor with which an input signal can be detected which has signal oscillations which are due to a rolling movement of the trailer or semitrailer, the signal oscillations superimposing a base portion of the input signal
• a calculation device which is designed to calculate a reference signal from the input signal, wherein the calculation takes place in such a way that the reference signal corresponds approximately to a reference signal determined from the basic component of the input signal
• a control device in which a manipulated variable can be determined as a function of a control deviation between the reference signal and a detected actual signal
• An actuator with which a driving condition of the towing vehicle in accordance with the determined manipulated variable can be influenced.
• the invention assumes that the input signal has a vibrational component, which is due to rolling movements of the trailer or semitrailer, and also contains a basic component, which is linked to the actual course of the vehicle. Based on this input signal, the calculation of the reference signal nals then made so that this approximately corresponds to a determined from the base portion of the input signal reference signal. This provides a reference signal reflecting the desired actual heading of the vehicle. On the basis of this reference signal can then be made reliable vehicle dynamics control.
• the signal oscillations are vibration components of the input signal which can be attributed directly or indirectly to the rolling movements of the hauler or semitrailer.
• the trailer's rolling motions directly affect the yaw rate of the vehicle as a possible input signal.
• An indirect influence occurs, for example, with regard to the steering angle when the steering movements are carried out to compensate for the yawing vibrations of the vehicle combination.
• the basic component superimposed by the oscillations is the remaining part of the input signal, which in particular reflects the course of the vehicle or the driver's desired course. This proportion can also have the value 0 if, for example, the vehicle is traveling straight ahead.
• an intermediate signal is calculated from the input signal in a correction step, which corresponds approximately to the base portion of the input signal, and that the intermediate signal is used for the determination of the reference signal. Since the intermediate signal corresponds at least approximately to the base component of the input signal, the reference signal in this embodiment can be determined from a modified input signal. That is, in the calculation of the reference signal is compared to the conventional calculation, only an additional signal processing step necessary in which the intermediate signal is determined.
• An embodiment of the method and the vehicle dynamics control system provides that the reference signal is a reference yaw rate signal and the actual signal is an actual yaw rate signal detected by means of a yaw rate sensor.
• a reference yaw rate is calculated on the basis of which the stabilization of the vehicle combination takes place.
• An embodiment of the method and the vehicle dynamics control system further includes that the reference signal is calculated on the basis of a vehicle model as a function of the intermediate signal.
• the input signal is a steering angle signal detected by means of a steering angle sensor.
• a Referenzgierratensignal can be determined in the invention in the usual way from the steering angle signal having a vibration component, in particular on
• Another embodiment of the method and the driving dynamics control system is characterized in that the input signal corresponds to the actual signal and the intermediate signal corresponds to the reference signal.
• the reference yaw rate signal can be determined directly from the detected yaw rate signal in the aforementioned correction step without a model calculation taking place.
• the embodiment has the particular advantage that the control deviation between the reference signal and the actual signal corresponds exactly to the oscillatory component of the input signal attributable to the rolling movements of the trailer or semitrailer.
• a refinement of the method and of the vehicle dynamics control system is characterized in that average values of successive extreme values of the input signal are formed in the correction step, and that the intermediate signal is determined in accordance with the average values.
• the attributable to the course request base portion of the reference signal is advantageously determined in this development using mean values of successive extrema of the input signal.
• the signal oscillations are calculated out of the input signal.
• a certain amount of time passes between the occurrence of two consecutive extrema of the input signal.
• an embodiment of the method and the vehicle dynamics control system provides that the intermediate signal or the reference signal is determined at a time by means of an extrapolation method from averages formed before the time.
• the intermediate signal which has been cleared of the signal oscillations, can also be realistically determined between the occurrence of two extrema of the input signal.
• signal changes taking place between the occurrence of two extrema can be taken into account in this way.
• one embodiment of the method and the vehicle dynamics control system includes that the mean values in the extrapolation method are provided with a weighting factor which is lower for mean values formed further back than for average values determined closer to the past.
• a refinement of the method and of the vehicle dynamics control system is characterized in that the intermediate signal is determined from the average values by means of a model-based filter. Due to its extensive parameterizability, the model-based filter generally allows a particularly flexible adjustment as to how far the intermediate signal is to be approximated to the input signal.
• An embodiment of the method and the apparatus is characterized in that the input signal is taken into account as a control variable and the intermediate signal as model output is taken into account within the model on which the filter is based.
• the model output variable is understood here to be the output variable of the model on which the filter is based, which as a rule is a state variable of the modeled system.
• a control size is understood in particular the Great, which represents the control input of the model.
• the filter is a Kalman filter.
• an embodiment of the method and the device provides that the manipulated variable is a steering torque with which a steering handle which can be operated by the driver is acted upon in order to influence the driving state of the vehicle.
• the manipulated variable is an additional steering angle with which a steering (superposition steering, electrohydraulic or electric steering) can be controlled in order to influence the driving state of the vehicle.
• the invention enables a stable control, in particular in this embodiment. In this case, the problem may arise that, due to the steering torque with which the steering handle is acted upon, a steering angle for compensating the tensioning vibrations is set, which is detected and used to form the reference yaw rate.
• the manipulated variable determined in the control device itself would be used to determine the reference variable, which generally leads to an unstable control.
• the reference yaw rate in the invention is calculated so as not to contain the vibration component resulting from the vibration component of the steering angle that compensates for the combination vibrations, such instabilities do not occur in the present invention.
• a computer program product that defines an algorithm that includes a method of the kind previously described.
• 1 is a block diagram of a control system in a first embodiment
• 2 is a diagram showing the course of a yaw rate during a driving maneuver of a towing vehicle with and without lurching trailer
• FIG. 3 is a block diagram of a calculation unit of the control system in a first embodiment
• Fig. 5 is a diagram illustrating the detection of a vibration-removed signal from a vibrating signal.
• FIG. 1 shows a schematic block diagram of a control system for stabilizing a vehicle combination in a first embodiment.
• the vehicle combination includes, for example, a two-axle, four-wheeled towing vehicle with steerable front wheels and a trailer coupled to the towing vehicle.
• the control system includes an activation device 101, in which rolling movements of the trailer are recognized in a manner basically known to those skilled in the art.
• the rolling movements of the trailer lead to harmonic signal oscillations of the Istgierratensignals ⁇ mes and a Querbetestungssig- nals.
• the frequencies of these signal oscillations are typically between approximately 0.5 Hz and 1.5 Hz. Harmonic oscillations with such frequencies can therefore be detected in order to detect rolling movements
• FIG. 1 shows a schematic block diagram of a control system for stabilizing a vehicle combination in a first embodiment.
• the vehicle combination includes, for example, a two-axle, four-wheeled towing vehicle with steerable front wheels and a trailer coupled to the
• yaw rate signal ⁇ mes Only the evaluation of the actual yaw rate signal ⁇ mes is shown by way of example in FIG.
• the detection of this signal is carried out by means of a yaw rate sensor, not shown in the figure.
• the lateral acceleration signal which can additionally or alternatively be taken into account, can be detected by means of a transverse acceleration sensor (also not shown in the figure).
• a control device 102 is activated, is calculated in the from of a control deviation ⁇ rra! Ter between a reference yaw rate signal ⁇ ref corr and the actual yaw rate signal ⁇ mes a manipulated variable accordance with which the drivability of the towing vehicle or the team can be influenced by means of an actuator.
• the activation mechanism is shown schematically in FIG. 1 by means of the switch 105.
• the control device 102 contains an adaptive proportional-derivative controller (PD controller), the controller parameter of which is, in particular, the vehicle speed v which can be determined, for example, from the signals from wheel speed sensors, the lateral acceleration a y detected by means of the lateral acceleration sensor Estimated value for the slip angle ⁇ of the towing vehicle determined on the basis of measured variables can be adapted.
• the controller output quantity is an additional steering angle ⁇ , whose adjustment on the steerable wheels of the towing vehicle leads to a stabilization of the combination or to the build-up of a yaw moment compensating the yaw oscillations.
• the additional steering angle ⁇ is set in one embodiment by means of a steering actuator on the steerable wheels of the vehicle.
• the steering angle set by the driver is superimposed with the additional steering angle, so that there is a steering angle at the steerable wheels, which results in the sum of the driver's steering angle and the additional steering angle.
• a steering torque is controlled by means of an actuator in the steering line of the towing vehicle, with which in particular the steering handle operated by the driver is acted upon. Based on this steering torque, the driver of the towing vehicle receives a recommendation for the execution of stabilizing steering movements. As shown in FIG.
• the steering torque AM is determined in a torque calculation device 201 from the additional steering angle ⁇ .
• the steering angle ⁇ H set at the steerable wheels is also taken into account when determining the steering torque AM.
• the determination takes place as a function of the vehicle speed v, the lateral acceleration a and the slip angle .beta. The inclusion of the slip angle is conceivable, but not necessary.
• the actuator for the control of the steering torque AM in the steering line is designed, for example, as an electronic power steering system which has an interface for external control by means of the control device 102.
• brake interventions can be made to stabilize the vehicle by means of a brake actuator.
• the controller output variable is preferably a yaw moment which is used to calculate wheel-specific brake forces, which are then set by means of the brake actuator.
• the reference yaw rate ⁇ re / jforr is determined in the embodiment of the control system shown in Figure 1 within the calculation means 104 based on a vehicle model, in particular from the steering angle signal ⁇ H. This indicates the steering angle, which has been set on the steerable wheels of the towing vehicle or on a steering wheel of the driver, and is detected by means of a steering angle sensor. Furthermore, further input variables, such as, for example, the vehicle speed v, can be used to calculate the reference yaw rate ⁇ re / jforr .
• the vehicle model a model known to those skilled in the art, such as, for example, a linear single-track model of the towing vehicle, can be used.
• Oscillations of the vehicle combination which result from rolling movements of the trailer, are usually also reflected in the steering angle signal ⁇ H.
• this is the case when a steering torque is impressed in the steering line of the towing vehicle to stabilize the team.
• This steering torque also has a periodically oscillating course for damping the vibrations, which is essentially in phase opposition to the yawing vibrations of the trailer.
• the phase relationship of the steering torque trailer vibration is dependent on the actuator (inertia in the steering). Important is the phase curve to the resulting steering angle on the wheel. This is then in fact approximately in phase opposition to the vibration. Because of the steering torque Steering movements are performed, the steering angle signal ⁇ H also vibrations.
• the invention is based on the assumption that the vehicle variables influenced by the chordal oscillations have a vibration component which is due to chuck vibrations.
• This vibration component superimposes a basic component, which is influenced only by the actual course of the vehicle or by the driver's desired course of the vehicle.
• FIG. 3 shows, by way of example, the time profile of the measured yaw rate ⁇ mes of a towing vehicle, in which the vibrations caused by the trailer oscillations can be recognized.
• the Istgierratensignal ⁇ mes results from a superposition between a determined by the Gespannschwingungen vibration component and a base portion, which reflects the course of the vehicle. This proportion is illustrated by the curve ⁇ Bas ⁇ s in FIG.
• the measured steering angle signal in principle has a similar swinging course as the Istgierratensignal ⁇ mes i in which a vibration component superimposed on a base ⁇ part , which corresponds to the course request of the driver.
• a reference yaw rate signal ⁇ ref korr is determined, which corresponds to the corresponding base part of a reference yaw rate.
• FIG. 4 shows an embodiment of the calculation device 104 on the basis of a schematic block diagram.
• the steering angle signal ⁇ H is fed to a block 401 in this embodiment.
• an intermediate signal ⁇ Hkorr is calculated from the steering angle signal in a manner to be described calculated, the ⁇ , the oscillation components of the steering angle signal does not include H, and close to approximately the base portion of the steering angle signal ⁇ corresponds to H, which represents the driver's intended direction.
• the intermediate signal ⁇ Hkorr is then used in the block 402 for calculating the reference yaw rate signal ⁇ ref korr on the basis of the vehicle model.
• FIG. 5 shows a further embodiment of the control system is shown, wherein the reference yaw rate signal ⁇ ref corr i n computing means is calculated 501 from the gemesse- NEN Istgierratensignal ⁇ mes.
• the reference yaw rate signal ⁇ ref corr i n computing means is calculated 501 from the gemesse- NEN Istgierratensignal ⁇ mes.
• the control system corresponds to the system shown in FIG.
• the reference yaw rate signal in this embodiment thus corresponds to the base portion of the Istgierratensignals ⁇ mes . It is assumed that the vehicle combination moves stable except for the occurring yaw vibrations.
• the advantage of this export approximate shape lies in the fact that the control deviation fi rm i he enau 9 represents the yaw oscillation of the vehicle combination.
• FIG. 5 shows by way of example a first signal Y having a vibration component, which may be, for example, the steering angle signal ⁇ H or the actual yaw rate signal ⁇ mes .
• the vibrations of the signal Y superimpose a base signal Y Bas ⁇ s , which is also shown in Figure 6.
• the mean value is here a value of the corrected signal Y corr.
• the mean value as the value of the signal Y corr set of the second local extremum of a pair of successive Ex Trema in the time of occurrence, so that for the signal Y corr particular in the time t t, the signal value Y t _ u is set.
• the average may be set as a signal value at any time between the occurrence of two consecutive local extrema.
• the second local extremum of a pair further represents the first local extremum of a subsequent pair of local extreme values, from which then in turn a signal value for the signal Y korr to be calculated is determined in the manner described above . That is, for example, that the local maximum value Y 1 in the time I 1, the first local extremum of a pair forms, which also includes the minimum value Y 1 + 1 at the time t ⁇ + ⁇ .
• the signal Y korr is preferably extrapolated on the basis of the previously determined support points.
• parameters of a function such as a polynomial of a certain order, are determined on the basis of the previously determined interpolation points.
• the signal value at a time after the calculation of the previous interpolation point then results as the function value of the determined function.
• a weighting factor is preferably used, the lower points of the spine are lower in weight than in the past. Such a weighting factor, which is often referred to as the "forgetting factor", takes less account of extra points in the extrapolation. At the same time, greater consideration is given to the original signal Y.
• the corrected signal is calculated by means of a Kalman filter on the basis of a single track model of the vehicle, which is determined by a PDT 2 or PT 2 ⁇ Ubertragungs is characterized.
• the Kalman filtering algorithm in each calculation cycle generally includes a prediction step and a correction step.
• A denotes here the system matrix, which reproduces the transmission behavior of the system.
• the transmission behavior determines the structure of the matrix A.
• the concrete values of parameters contained in the matrix must be adapted to the respective vehicle, which can be carried out, for example, in the context of driving tests.
• the system state to be estimated corresponds in the context of the invention to the correct greedy signal Y corr . Due to the transfer behavior, the equation of state is a difference equation of the second order for the one-dimensional state variable, which is converted into a first-order equation system according to a method which is fundamentally familiar to a person skilled in the art.
• the state vector In addition to the signal value Y korr (k), the state vector also contains the signal value at time k-1 at time k.
• the state vectors in equation (3) are therefore two-dimensional; Matrix A is a 2x2 matrix.
• the control input u k the measured signal Y is used.
• the so-called Kalman gain K k is first determined by means of
• the matrix H indicates the relationship between the measured variables and the state variables considered and the matrix R the measurement noise.
• the measured variables used here are the mean values of the extrema of the signal Y determined in the manner described above, so that the matrix H corresponds to the unit element.
• the matrix R is chosen appropriately.
• the current estimated value x k of the state is determined by the equation calculated, wherein the measured variable y k corresponds to the mean determined in the cycle k.
• the error covariance matrix P k to be used in the prediction step of the subsequent cycle is passed through
• the Kalman filter can thus shown approximation approximately an adjusted signal from the vibrations of the input signal Y base signal Y are determined corr.
• the Kalman filter has the advantage over extrapolation that, by means of an appropriate selection of the measurement noise (matrix R) and the system noise (matrix Q), it can be set particularly flexibly to what extent the signal Y corr matches the measured signal Y. should.
• a temporal weighting of the mean values in the form of a forgetting factor can be provided in the Kalman filter.
• the invention provides a control system with which a vehicle combination can be stabilized in case of rolling movements of the trailer or semitrailer by interventions in the steering system or by wheel-specific braking interventions. Since the Gespannschwingept above a certain

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• 2006
  • 2006-11-16 EP EP06819566.8A patent/EP1954537B1/de active Active
  • 2006-11-16 WO PCT/EP2006/068591 patent/WO2007060135A1/de active Application Filing
  • 2006-11-16 JP JP2008540617A patent/JP2009516614A/ja not_active Withdrawn
  • 2006-11-16 US US12/094,435 patent/US8046147B2/en active Active

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