KR20070016160A - Method for compensating a dynamic axle load transfer - Google Patents

Abstract

The present invention relates to a method for at least partially canceling the dynamic transmission of axle loads in a vehicle, wherein the drive moment is increased or decreased without substantially changing the speed of the vehicle for offsetting. Thus, the demand for drive moments is provided so that a time-limited substantial drive moment is formed during the first time to counteract the transmission of the axle load. In addition, during the first hour, the present invention proposes a control device and a microprocessor for carrying out the method according to the present invention. In addition, the vehicle drive is equipped with a control unit or a microprocessor. The software is in turn configured to carry out the method. At least, the vehicle is equipped with a control device or a microprocessor for the execution of the software for carrying out the method according to the invention.

Description

Method for compensating a dynamic axle load transfer

The invention relates to a method for at least partially canceling the dynamic transfer of axle loads in a motor vehicle according to claim 1. Furthermore, the present invention provides a microprocessor for performing the method according to claim 15; A control device according to claim 16; 18. An internal combustion engine according to claim 17, comprising the control device and / or the microprocessor; Software suitable for such an arrangement, according to claim 18; A vehicle according to claim 19 relates to a vehicle equipped with them.

In the art, the dynamic transfer of axle loads due to vehicle acceleration or deceleration is characterized by the opposite direction of the momentary normal force against the frontal axle and the rear axle. opposite sense). Due to the tire cornering force's dependence on vertical drag, the distribution of the lateral force between the front and rear axles changes, resulting in momentary turning into the curve during deceleration A momentary turn out of the curve occurs during acceleration.

Thus, under certain driving conditions, for example, driving at maximum speed on a curve, or under rapid braking, the driver has a subjective feeling that the vehicle is inclined toward the front wheel, where at least one wheel Silver is known to deflect to maximum.

In particular, in the case of full braking, the vehicle is inclined severely downwards towards the forward direction of travel as a result of the dynamic transmission of the axle load. As a result, the tires on the front axle are subjected to extremely heavy loads and can no longer follow the linear operating point. At these operating points, the longitudinal and transverse forces that can be transmitted are smaller in the linear range. At the same time, the load on the tires on the rear axle is substantially reduced, and as a result, they can only transmit low braking and turning force. Controlled control of the vehicle, which the driver desires, is frequently impossible without a system that controls the dynamics of the vehicle's movement.

For this reason, the reduction of the load on the rear axle in case of complete braking while driving, or rushing or at full speed on the curve, means that the rear wheels are fully lifted from the road on the inside surface of the curve and no longer apply braking or lateral forces. It may be undeliverable. Thereafter, the front wheels on the outer side of the curve and the rear wheels on the outer side of the curve are frequently loaded in such a way that these wheels begin to slide and ultimately the vehicle is broken.

In connection with the development of an integrated chassis control system (ICC) which is known in the art to date, by networking the essential systems for the dynamics of vehicle movements as interactive dynamic driving systems (IDS) Efforts are being made to stabilize the vehicle in all perceivable driving situations. For this reason, systems and / or Electronic Stability Programs (ESPs) that control the role of the vehicle's movements communicate with additional control devices, for example brake assistants. The individual items of data required by the system are transmitted via the data bus system ("Controller Area Network", CAN bus). This allows data to be sent to data bus systems at different speeds, depending on their importance. By way of example, in relation to the dynamics of vehicle movement, a time-sensitive signal is transmitted on a “high speed” data bus with a data transfer rate of at least 500 kb per second. Thus, by way of example, the dynamic transference of axle loads that occur when the vehicle is tilted toward the front wheel can be detected in real time, and in order to recoup the transfer of axle loads, for example by means of an electronic damping control process. A damping regulation process (CDC) can be activated. This expensive electronic braking control system is controlled, for example, by a solenoid valve whose characteristics can be continuously adjusted to suit road conditions, vehicle movements and driving patterns in an accurate and continuous automatic manner according to valid data. Based on a shock absorber. Several acceleration sensors and the like, in conjunction with additional signals from the CAN bus, can provide the signals required for CDC control optimum braking. The control device calculates in real time the required damping force for each wheel, for example by means of characteristic diagrams. The fit of the shock absorber can then proceed within milliseconds. Thus the vehicle body can be kept stable; During braking, body movements are noticeably reduced when running or crashing on pitching and curves.

Although this success and improvement in the dynamic movement of axle loads, which can be achieved through this, has proved to be promising and satisfactory in the art, it is still insufficient to control the vehicle in a safe and secure manner in all driving situations.

It is therefore an object of the present invention to propose a method for auxiliary offsetting changes in the opposite direction of temporary vertical drag on the front and / or rear axles caused by the dynamic transmission of axle loads in a vehicle.

Another object of the invention is to propose a device suitable for carrying out the method according to the invention.

This object is achieved in each case by the individual features of claims 15 to 19 from the features of claim 1 and from the apparatus point of view.

For this reason, a method for at least partially canceling the dynamic transmission of axle loads in a vehicle is proposed, wherein the drive moment is increased for the purpose of offsetting the movement of the axle loads without substantially changing the speed of the vehicle. Or reduced.

In particular, for example, a method for canceling the dynamic transmission of axle loads when a part of the vehicle load is inclined towards at least one front wheel is proposed, for the purpose of offsetting or offsetting the movement of the axle loads. Or a change in the accelerator stroke is applied, or kick down is initiated. In particular, in the case of a full breaking action, a change in the drive moment or accelerator stroke applied at the start of the full braking action is proposed. Furthermore, to reduce dipping motion and to prevent breakage during braking while driving on a curve or when braking while driving on a curve, it is applied during braking on the curve or when braking on the curve. Changing drive moments or accelerator strokes is suggested.

In internal simulations performed by the Applicant, it has surprisingly been demonstrated that the offset or balance of the dynamic transmission of the axle load can be realized by changing the drive moment.

This change, in particular a short increase in drive moment, is a butterfly valve in the case of gasoline or diesel engines, for example with the appropriate intervention in the engine management system, for example with the application of an accelerator stroke. by changing the position of the butterfly valve or the throughput of the injection pump, or by changing the fuel mixture. For example, in the case of a vehicle equipped with a fuel cell, propelled by an electric motor, having a gas propulsion unit, or designed as a hybrid vehicle, the planned increase in the desired size and duration of the drive moment is an example. By means of a suitable increase in electrical power or equivalent.

Until now, it has been considered that interventions to influence the dynamic transmission of axle loads can be achieved by chassis, in particular by shock absorbers and stabilizers. Thus all known driving stabilization systems aim to control and / or adjust the individual operating states of the chassis. The possibility of changing the drive moment to affect the dynamic transfer of axle loads has not been considered so far.

In contrast, the present invention complements Applicants' previous efforts to achieve meaningful effects on the dynamic transfer of axle loads in vehicles in a very surprising and advanced manner. In the course of all these efforts, the skilled person did not envision the invention of incorporating such an engine control system.

In contrast, the present invention takes a new route. This is a surprising advantage of the invention described herein, in other words, the offset of the dynamic movement of the axle load can be achieved by a change, preferably by a short increase in the driving moment, in particular by an accelerator stroke.

If the vehicle is inclined to one side, for example due to full braking action, and as a result, the wheel contact force at the front axle rises initially at large scale due to the forward-directed dynamic transmission of the axle load, Cause a simultaneous decrease in load. As a result, the rear tire loses contact force and the lateral cornering force decreases drastically. This tilt effect is exactly the opposite of the case of rapid acceleration of the vehicle. The vehicle is lifted up front and sinks back. The rear axle is weighted more heavily, and the front axle is reduced in load. The invention, which is first proposed in this specification and related to the method of intentionally influencing the dynamic transmission of axle loads, is intended to provide maximum braking for the purpose of rapid acceleration or rapid acceleration without substantially affecting the acceleration of the vehicle. The positive advantage of this known tilt reaction of the vehicle, which occurs when full power is applied, is obtained.

Furthermore, in the present invention, the response of the vehicle is substantially the balancing righting of the vehicle, achieving an offset for the dynamic transmission of the axle load, increasing or adapting the vertical drag and / or accelerating the acceleration of the vehicle almost In order to achieve a lateral force of the tire which is effectively transmitted to the front and / or rear axle, a short increase in the driving moment is, for example, at the time of braking in the case of braking action or at the maximum speed in the curve. For the first time, it should be applied at the critical swerving point when driving on a road.

Thus, sudden deswers can be avoided during full braking operation. Furthermore, sudden oversteering can be reduced. The risk of rolling movement is reduced, and finally, the risk of sliding is reduced.

The present invention first utilizes the result that the time constant between the increase in the drive moment and the response of such a vehicle becomes large. Thus, the vehicle responds slowly to the required drive moment due to inertia. As a result, although drive moments can actually affect the drive train up to the drive wheels, they still do not accelerate. In addition, during braking, an increase in wheel contact force at the rear axle can be reliably achieved while the vehicle's acceleration is not at all possible by the drive torque resisting several times higher braking force. .

This produces a reaction force involving at least some righting of the vehicle, but the acceleration of the vehicle is not objectively detected at all. Deterministic driving that occurs in an instant, due to counter-balancing of the dynamic transmission of the axle load from at least partial straightening of the vehicle, that is to a position where the axle load distribution is substantially balanced from the existing excessive front position. The situation is managed in an advantageous manner in which sufficient contact force on the rear wheels is achieved so that substantially higher braking and lateral forces can be transmitted than in conventional cases.

The discovery of these positive effects on the dynamic transfer of axle loads by the application of accelerator strokes in critical driving situations such as, for example, full braking or driving at full speed on a curve, results in braking or maximum speed on the curve. It is further surprising that the increase in the driving moment when driving at is an absolute contraindication to the skilled person.

A more surprising finding is that with full braking or the generation of additional drive moments when driving on a curve, the dynamic transmission of the axle load in the forward direction can be reduced and offsetting for the transmission of the axle load can be achieved. .

For this reason, in an advantageous manner, the pitching angle has a more quickly dissipated, less visible, or more dampened waveform due to the cancellation of the dynamic transmission of the axle load. Thus, in a more advantageous way, the variation in wheel loading becomes smaller. As a result, higher wheel braking pressure is achieved. Higher wheel braking pressures mean greater deceleration. As a result, the ABS can be braked later in an advantageous manner, that is to say, the tire starts to slide later. As a result, the ABS braking operation can be further optimized in an advantageous manner. When braking at the curve, due to the higher rear axle load, greater stability and more lateral force can be achieved.

Particularly advantageously, there is a new stabilizing magnitude, that is to say a valid driving moment in the ICC group, with a time limited demand for the driving moment. In an advantageous way, no additional sensor is needed. Even more beneficial is the fact that no additional hardware is required. Furthermore, the method according to the invention may be reproduced in an advantageous manner in the form of a software application that can be installed on an existing microprocessor or executed by an existing control device.

Preferred embodiments of the invention are apparent from the features of the following claims.

Thus, in a preferred embodiment, a method is proposed which is characterized by, for example, the following steps: a) By way of example, a travel stability system or parts thereof, for example ESP, EHPS, CDC, brake assistant. In order to provide information items on the individual situation-dependent settings of the chassis, brakes and / or steering used in the framework of the integrated chassis control system for control of IDS, UCL, etc. Determine the value of the data valid for the general situation of such a vehicle, which can be transferred from the sense or the like to the microprocessor, the control device, or the like; b) determine the critical situation of the vehicle in which the dynamic transfer of axle loads should be controlled or balanced; c) defining the magnitude of the drive moment required; d) limit the duration of the drive moment required; e) Initiate the required drive moment at a pre-determined scale and a predetermined duration by applying a drive moment demand.

For this reason, by appropriately controlling the electrically and / or electromechanically frequently operated burner valves or injection pumps, the application of the demands on the drive moment is advantageous, for example, in a configuration. In general, this can be done in a relatively simple manner, where possible, without additional structural expenditure.

In a more preferred embodiment, a method of performing a complete braking operation with ABS support is proposed. As a result, the advantage of the planned adjustment of the dynamic transmission of the axle load by the control of the drive moment can be combined with the advantage of the ABS supported braking process. In addition, the data available on the CAN bus of the vehicle can be obtained from the individual control devices, and the required reactions can be more effectively harmonized and further optimized.

In a preferred embodiment, the presence of a complete braking action is determined which is determined by the detection of an ABS flag symbolizing the point of time when the braking is applied or by the evaluation of the gradient of the brake pedal. Alternatively, the existence of a complete braking action is determined in an advantageous manner, determined by detecting the angular setting of the brake pedal, for example a fully depressed brake pedal lying on an end stop. Here, in an advantageous manner, there is a piezo-electric crystal, a pressure sensor, a contact switch or a similar component on the back of the brake pedal which sends a control signal immediately after the brake pedal is fully pressed down. Is provided. Alternatively, an angle sensor that signals when a pre-determined limiting angle is exceeded may also be provided to the brake pedal. Furthermore, the presence of a complete braking action can be determined by evaluating the rising degree of brake pressure in the master brake cylinder.

Then, according to the limiting value signal of this characteristic, a time limited alteration of the driving moment can be initiated.

In a more preferred embodiment, by calculating the value of the data from the ESP, a threshold situation in the curve is proposed. Here, by utilizing the interplay between the drive control device and the data present in the system to control the dynamics of the vehicle movement, the dynamic transmission of the axle loads is initiated as needed by initiating a time-limited drive moment. Good control-instance in which the cancellation of can be achieved is advantageously calculated.

According to a more preferred embodiment, from 250 milliseconds to 750 milliseconds, preferably initiated in a critical situation during an increase in dynamic moment, especially during braking at the time of applying the braking or for example after the first appearance of the roll. Is proposed for a full power kick-down or pulse of 300 milliseconds to 500 milliseconds duration. Increasing the drive moment, in particular this step in relation to the time or duration of the maximum power pulse, can be established as particularly beneficial in the initial internal simulation by the applicant using an internal computer model.

In another preferred embodiment, -0.5 seconds to +1.0 seconds, preferably -0.01 seconds to +0.5 seconds, the most, with the increase in drive moment, in particular the time of braking being the theoretical zero time point. A pulse or kick-down of maximum power, which is preferably initiated in a time window of +0.05 seconds to +0.25 seconds, is proposed. Thus, in an advantageous manner, the drive or inertia of the internal combustion engine and the drive train in response to the opening of the butterfly valve with an extremely small but never zero delay, by reacting the drive moment at the right time Reaction forces are considered in such a way as to induce counter-balancing of the dynamic transmission of the axle load from the vehicle at least partially righting or from the existing excessively forward position to a substantially balanced state of the vehicle. This realizes the benefits of higher wheel contact forces and improved transmissibility of braking and transverse forces.

In another preferred embodiment, a method for maximum power kick-down or pulse is proposed which is implemented in a pulsed manner by a plural increase of the drive moment, in particular an accelerator stroke or a maximum power pulse. For this reason, the benefits of braking pressure regulation as known from ABS technology are newly achieved in a kind of controlled increase of the driving moment, in particular in the regulated complete accelerator stroke. This improves the controllability of the system and the matching of forces and moments that can be calculated by the application of a pulsed or controlled increase in drive moment. In addition, increased driving moment may be required in conjunction with pitching oscillation.

In a preferred embodiment, a method is proposed for a pulsed increase in drive moment, each having a duration of 50 milliseconds to 150 milliseconds, in part up to 1 second, preferably approximately 100 milliseconds.

In a more preferred embodiment, a drive moment of from 100 newton meters to 500 newton meters, preferably at least 250 newton meters, particularly preferably at least 270 newton meters, which is caused by a short increase in drive moment is proposed. The desired effect of the dynamic transmission of axle loads is possible using engine torques of magnitude up to 350 Newton meters or even up to 500 Newton meters. For this reason, for example, engine torque of at least 250 Newton meters, at least 270 Newton meters, or at least 300 Newton meters is still countered by at least about 3000 Newton meters or more of braking force and moment, and therefore in practical applications, braking torque between 10: 1 and 20: 1 is typically present between the torque and the drive moment. This ensures that the straightening and offsetting of the vehicle, ie the optimization of the dynamic transmission of the axle load, is securely ensured without considering the acceleration of the vehicle.

The advantages and positive aspects described above of the method according to the invention can be implemented in a similar manner by using the proposed microprocessor for this purpose and also by using the proposed control device for this purpose. These advantages can similarly be achieved using the internal combustion engine according to the invention, which is equipped with a corresponding control device and / or a microprocessor for carrying out the method of the invention. The same applies to software for carrying out the method, which is installed in and executed on a vehicle equipped with them and a suitable microprocessor or suitable control device.

1 shows various items of data from figures a) to d) from measured values formed in the case of a complete braking operation supported by ABS at a speed of 100 km / h during linear movement;

FIG. 2 shows a reference speed with respect to the measured data shown in FIG. 1, supplemented by corresponding simulation result values for differentiation, in a) of FIG. 2, and b) of FIG. 2 shows the driving moment associated therewith. The simulation is shown by thick and dark lines, and the measurements by thin and blurry lines.

3 is a diagram comparing simulation data according to measurement regarding wheel speeds of four wheels of a vehicle corresponding to the states shown in FIGS. 1 and 2;

4 shows the corresponding braking pressure associated with each wheel for the simulations shown in FIGS. 1-3.

FIG. 5 shows a) of FIG. 5 and b) of FIG. 5, a) of FIG. 5 shows the attached ABS flag, b) of FIG. 5 shows the VSC signal waveform, and the simulation is thick and dark dotted line. The measurements are shown as thin, blurred lines.

FIG. 6 shows a simulation according to the kick-down of a full braking operation supported by ABS from 100 km / h when traveling in a straight line and a simulation without kick-down, and in comparison with that shown in FIG. 6 shows the reference velocity over time, and FIG. 6 b shows the driving moment over time.

FIG. 7 shows the wheel speeds of the four wheels associated with the drive state shown in FIG. 6 in FIGS. A) to d) of FIG. 7, with simulations following kick-down and simulations without kick-down.

8 shows the pitch rate for the drive speed shown in FIGS. 6 and 7 in b) of FIG. 8 and the associated pitch angle of the vehicle in a) of FIG.

FIG. 9 shows in a) to d) the contact forces associated with each wheel for the state shown in FIGS. 6 to 8;

10 shows the braking pressure on each wheel according to the states shown in FIGS. 6-9 in FIGS. A) to d).

FIG. 11 shows the simulation without kick down as thick and dark dotted lines and the simulation following the kick-down as thin and blurred lines, FIG. A) shows the associated ABS flag and b) the VSC signal waveform.

FIG. 12 shows measurement of various data for a driving state based on 108 km / h similarly to FIG.

FIG. 13 shows a reference speed (km / h) associated with the driving state shown in FIG. 12 in FIG. A) and the driving moment Nm associated therewith in FIG.

FIG. 14 shows the simulated wheel speed (thick or thick solid line) and the measured wheel speed (thin or faint solid line) of four wheels in the driving states shown in FIGS. 12 and 13 in the lower views a) to b). Figure.

FIG. 15 shows the individual brake pressures of each wheel in the lower views a) to d).

FIG. 16 shows the waveform of the ABS flag in lower figure a) and the waveform of the VSC signal characteristic curve in lower figure b).

FIG. 17 shows yaw rate in the lower view a) and transverse acceleration in the situation depicted in FIGS. 12 to 16 in the lower view b).

FIG. 18 shows the first simulation form without a kick-down (thick or thick solid line) and the second simulation form according to the invention with a kick-down for comparison purposes, based on the knowledge deduced from FIGS. A driving situation based on 108 km / h using the excursion of steering with complete braking as depicted in FIG. 12, in thin or faint solid lines).

FIG. 19 shows the relative appertaining deviation of the vehicle in the y-direction with respect to the covered distances written in the figure along the x axis in the lower figure a) and at the time written in the figure along the x axis in the lower figure b). Fig. 6 shows the excursion of the vehicle in the drawing along the y axis, in which the thick or thick solid line represents the simulation without kick-down and the thin or faint solid line is kick-down, as in FIGS. Figure showing a simulation with.

FIG. 20 shows the wheel speeds in the situations depicted in FIGS. 18 and 19, in the form of simulations without kick-down and simulations with kick-down, in the lower views a) to d).

FIG. 21 shows the pitch angle of the vehicle in the situation depicted in FIGS. 18-20 in the lower view a) and the associated pitch rate in the lower view d). Thick or thick solid line without down, thin or faint solid line with kick-down)

FIG. 22 shows, in lower views a) to d), the associated contact force for each wheel in the situation depicted in FIGS. 18 to 21.

FIG. 23 shows the lateral forces that can be transmitted to each wheel in the driving situation according to FIGS. 18 to 22, in sub-views a) to d).

FIG. 24 shows the starting situation for the first 100 km / h with full braking with ABS when driving with the right curve, where in each case a simulation form (thick or thick solid line) with no kick-down and kick In the simulation form with a down (thin or faint solid line), the reference speed is shown in the lower figure a) and the driving moment in the lower figure b).

FIG. 25 is a sub-view a) to d) relating to yaw rate, longitudinal acceleration, transverse acceleration and attitude angle in the situation depicted in FIG. Figure depicting the data.

FIG. 26 shows the individual wheel speeds of the four wheels in the situations depicted in FIGS. 24 and 25, in sub-views a) to d) (with thick or thick solid lines, with kick-down in the absence of kick-down). Thin or faint solid lines)

FIG. 27 shows the relevant braking pressures for the four wheels in the situations depicted in FIGS. 24 to 26, in the lower views a) to d).

FIG. 28 shows the pitch angle in the lower view a) in the situation depicted in FIGS. 24 to 27 and the pitch rate in the lower view b).

FIG. 29 shows the contact force for each wheel in the situation depicted in FIGS. 24 to 28 in the sub-views a) to d).

FIG. 30 shows the lateral forces that can be transmitted to each wheel in the situations depicted in FIGS. 24 to 29 in the lower views a) to d).

31 shows the waveform of the vehicle's pitch angular velocity with respect to time without braking-down (braking or thin solid line "A") during braking and the pitch rate for a complete braking operation with kick-down for the purpose of comparison. Four typical line waveforms “B” to “E”, where the first example shows a kick-down at the time of braking (thick or thick solid line “B”), and the second example shows 0.1 second kick-down (thick or thick solid line "C"), the third example shows kick-down 0.2 second after braking (thick or thick solid line "D"), and the fourth The example shows a kick-down after 0.3 seconds at the time of braking (medium intensity dash-dotted line "E").

The driving state of the first example in which a full braking action is performed after traveling along a straight line at a speed of 100 km / h is shown in FIGS. 1 to 5. Dynamic transmission of the axle load occurs during full braking. The dynamic transmission depends on everything else on the height of the center of gravity of the vehicle. The dynamic transmission of axle loads changes the contact force of the vehicle. The ratio between the braking torque of the vehicle and the drive moment is approximately 10: 1 to 20: 1. During the full braking operation of blocking the wheel, the moment can only be supported by the rear axle since the wheel is not accelerated due to the relatively high braking torque if the driving moment is increased for a short time. This effect increases the contact force of the wheel on the rear axle and reduces the contact force of the wheel on the front axle. Since the vehicle has a relatively large mass inertia, any acceleration of the vehicle can be formed sufficiently small or it can be reduced when the driving moment is acting for only a short period of time.

As measured, FIG. 1A) shows the position of the accelerator pedal relative to time in percentage. FIG. 1 b) shows the waveform of the brake circuit signal (BLS) measured over time or the position of the brake pedal in percentage. As can be seen from the measurement, at approximately 1.8 seconds, the brake pedal is fully depressed and a BLS signal is generated abruptly indicating full braking operation. In FIG. 1C), the waveform of the brake cylinder pressure at the bar is shown over time. Here, the braking pressure rapidly formed as the complete braking operation according to FIG. 1 b is initiated correlates with the measured value. In addition, the measured steering angle is shown in FIG. 1 d), which angle is formed at 0 ° before braking action, and 0 ° in the range of +/− 5 ° after braking is fully applied. Weakly irregularly formed with respect to the line.

The result of the measurement shown in FIG. 1 is recorded, which results in a friction coefficient of μ = 1.1 between the dry road and the tire road-contact area and the tire pressure of the rear tire of 3.2 bar and the front tire of 2.7 bar. The results were tested using tires supporting the Turanza, 215/55 / R16 type under the trade name Bridgestone.

The driving state shown in FIG. 1 is additionally shown in FIG. 2. Figure 2a shows a waveform of velocity (km / h) with respect to time (seconds). 2B shows the waveform of the drive moment Nm over time (seconds). The measured values are shown by thin or relatively blurry lines. Simulated items of data are provided in thick or relatively dark lines. The simulation is relatively well matched with the measured data. Therefore, the selected simulation, that is, a complex series of equations based on the simulation, proved to accurately represent the measured operating state.

In FIG. 3, the speed (km / h) of each wheel over time (seconds) is shown in a) to d) of FIG. 3. The measured data is shown again in thin or blurry lines. Simulations are shown using thick or dark lines. The front left wheel is shown in a) of FIG. 3. 3 b shows values for the front right wheel. The rear left wheel is shown in c) of FIG. 3. The rear right wheel is shown in d) of FIG. 3. It becomes clearer from the direct comparison of simulations and measurements, and simulations replicate the measurements appropriately.

The detail sheet of the drawing shown in FIG. 3 is used as an additional drawing so that the numbering or referencing system for the state shown along each wheel from front left to rear right is used in the lower drawings a) to d). do. The figure a) of the upper left is thus shown from d left representing the right rear wheel to the right rear wheel.

Thus, in FIG. 4, the braking pressure at the front left wheel is shown in a) of FIG. 4, the braking pressure at the front right wheel is shown in b) of FIG. 4, and the braking pressure at the rear left wheel is shown in FIG. 4. As shown in c), the braking pressure in the rear right wheel is shown in d) of FIG. 4, where the thin or blurry lines represent the measured data and the thick or dark lines represent the simulation. Here, measurements and simulations are better matched.

In FIG. 5, the waveform of the ABS flag with respect to time is shown in a) of FIG. 5. According to this figure, the ABS flag is formed somewhat similarly as the brake pedal is pressed in both measurement and simulation. 5 b shows the waveform of the VSC signal, which is suitable for a “vehicle safety control” system, ie a VSC system, in which the simulation and the measurement are exactly matched.

The exemplary states mentioned in FIGS. 1-5 are described again in FIGS. 6-11, which initiate an initial speed of 100 km / h and a straight run, after which a full braking occurs suddenly but kick-down. Two simulations (thin or blurry lines) of simulation without kick-down (thick or dark dotted line) and simulation with kick-down are shown in contrast to each other.

6 a) shows the reference velocity versus time in seconds that decreases linearly with the onset of complete braking. FIG. 6 b shows the driving moment Nm over time, which values are formed relatively continuously under 50 Newton meters but for a simulation involving kick-down approximately 1.9 seconds after the start of the simulation. Increases to over 250 Newton meters and then drops suddenly again after 0.3 seconds. A jump-like increase in the drive moment of an engine exceeding 250 Nm occurs by kick-down, which is used for the purpose of balancing or offsetting the dynamic axle load distribution. Results from the combustion of the gas.

The speeds of the four wheels of the vehicle are again shown in a) to d) of FIG. 7. Thick or dark lines show the simulation without kick-down. Thin or blurry lines depict the simulation with kick-down. This difference in shading will be maintained in all additional figures showing simulation data.

After a full braking operation, the reduction of the wheel speed of the four wheels over time can be noticed according to FIG. 7, and it is shown that the kick-down has no effect on the deceleration. The wheel speeds harmonize well with both kick-down and non-kick-down simulations, and more clearly show the improvement achieved on the front axle (initiation of wheel slip) at the braking point due to kick-down. do. Thus, the vehicle does not accelerate despite the kick-down.

The state shown in FIG. 8 is a quite different state. FIG. 8 a shows the vehicle's pitch angle with respect to time, and FIG. 8 b shows the pitch rate with respect to time. The pitch angle here is not quite significant and vibrates weakly at full braking due to kick-down rather than pitch angle without kick-down. Equally, the pitch rate does not form significantly, oscillates weaker and then disappears more quickly. The method according to the invention is thus suitable for improving or offsetting the dynamic transmission of axle loads during, for example, full braking operation by accelerator stroke.

In FIG. 9, the contact force on each wheel according to the state shown in FIGS. 6 to 11 is shown in FIG. A) for the front left wheel and in d) for the rear right wheel. Here, thin or blurry lines for the kick-down simulation are somewhat unbiased and have a lower contact force on the front wheel than without the kick-down. This means that a critical state of contact force, which can be generally expected, is obtained due to the dynamic transmission of the axle load in the forward direction when the vehicle dives are suppressed. On the other hand, based on the contact force on the rear wheel, the braking force appears higher than the state without the kick-down at the time of braking, and thus, the braking force that causes a more stable driving state can be transmitted better.

In addition, according to FIG. 8, the kick-down provided at 1.94 seconds from the start of the measurement causes a decrease in the pitch angle of approximately 10%.

In addition, according to FIG. 9 without kick-down, the two front wheels must withstand tire contact forces in excess of approximately 8000 Newtons, thereby forming a linear transmission range of the tire and entering the critical range. In contrast, the contact force following the kick-down is formed at approximately 8000 Newtons, which still forms in the linear range. In conclusion, improved operation can be reached in this state. In addition, as shown in c) and d) of Figure 9, an increase of at least 200 Newtons in the contact force on the rear wheels is recorded compared to the simulation without kick-down, which implies additional transmission of lateral turning and braking force. do.

Accordingly, the translation of the axle load can be at least partially offset by the effect of the drive moment. Since the contact force of the wheels on the front axle is reduced, the tire cannot enter or reach the limit of the transmissible longitudinal load alone. In the limiting range, the tires may or may not be able to carry additional longitudinal loads due to already increased contact forces, even many tires have reduced longitudinal loads at this point. This can be better understood due to the speed of the wheel shown in FIG. 7. Due to the partial offset of the dynamic transmission of the axle load, the wheel slips not much on the front axle during braking (at approximately 2 seconds). The contact force of the wheels on the rear axle is made quite large due to the compensation process. Alternately, the braking pressure at the rear axle can be formed at a relatively large level, which means that it is well decelerated, and thus the braking distance is shortened. The level of braking pressure at the front axle is excellent because no relatively heavy contact force is applied to the tire (c.f. 9 and 10). According to FIG. 8, the pitching moment can be partially canceled due to the deliberate effect of forming the driving moment during braking, and the pitching motion disappears more quickly.

This drive state is shown in FIG. 11 only for completeness, the ABS flag is shown in a) of FIG. 11 and the VSC waveform is shown in b) of FIG.

Other examples of driving states in accordance with the measurements are shown in FIGS. 12-17. Based on the initial run in a straight line and the speed 108 km / h, the evasive manoeuvre is driven around the cone in a left-right combination that is braking or simulated here within the adjustable range of the ABS system. ).

In a manner similar to that of FIG. 1, the percent position of the accelerator pedal over time is shown in a) of FIG. 12. The position of the brake pedal relative to time is recorded in b) of FIG. 12. After starting the measurement, you can see that the brake pedal is fully depressed at about 0.8 seconds. The brake cylinder pressure recorded in the bar is thus formed in a corresponding manner as shown in Fig. 12C. The steering angle is shown in d) of FIG. 12. In full braking, this process of driving starts around the cone.

The associated reference speed is shown in a) of FIG. 13. Thin or relatively blurry lines represent measurements as shown in FIG. 2. Thick or relatively dark lines represent simulations. Simulation and measurement are relatively well matched. The applied drive moment of the engine is shown in b) of FIG. 13. In addition, measurements (thin or relatively blurry lines) and simulation (thick or relatively dark lines) are in good agreement with each other. This is used to apply to computer models.

In FIG. 14, the waveform of each wheel speed over time is shown, the front left wheel is shown in a) of FIG. 14 and the rear right wheel is shown in d) of FIG. 14.

Thus, the braking pressures applied to each wheel from front left to rear right in FIG. 15 depend on FIG. 15 depending on the case of measurement (thin or relatively blurred line) and the case of simulation (thick or relatively dark line). Are shown in a) to d). In addition, measurements and simulations are better matched and can be written for further simulation.

For completeness only, the ABS flag over time is shown in a) of FIG. 16 for simulation and measurement, and the VSC waveform is shown in b) of FIG.

FIG. 17 reproduces the lateral acceleration in b) of FIG. 17 and yaw rate with respect to time in a) of FIG. 17, the measurements being shown in the form of thin or blurry lines, the simulation being thick or dark. It is shown in the form of a line. The waveform of the lateral acceleration follows the expected course that matches the cone combination being driven. Equally, yaw speed is increased to cause rotation of the vehicle about the vertical axis.

The drive state shown in FIGS. 12-17 is a trade name with a friction coefficient of μ = 1.1 between the dry road and the tire road-contact area and tire pressure of the rear tire of 3.2 bar and the front tire of 2.7 bar. Full braking action and initial speed of 108 km / h when driving in or around a cone of avoided maneuvering, simulated or measured using tires bearing the Bridgestone Turanza, 215/55 / R16 type It includes.

12 to 17 is a form of simulation according to kick-down at the start of a complete braking operation in order to clarify the improvement of the driving state that can be reached due to the kick-down formed at the start of the braking process. (Thin or relatively blurred lines) and in the form of a simulation without kick-down (thick or relatively dark lines) are shown in FIGS. 18-23, from which the engine torque is supplied rapidly.

In FIG. 18, the reference velocity with respect to time is shown in a) of FIG. 18. Thick or relatively dark lines show simulations without kick-down, and thin or relatively blurred lines show simulations following kick-down. Therefore, the driving moment Nm with respect to time is shown in b) of FIG. According to the time graph shown, a kick-down occurs approximately 0.8 seconds after the simulation is started. Here the kick-down takes approximately 0.4 seconds while the total moment of inertia drops to -50 Newton meters and then exceeds 250 Newton meters.

As shown in a) of FIG. 19, the transverse displacement of the vehicle in the y-direction required or reachable to drive around an obstacle is less in case of simulations following kick-down than in simulations without kick-down. More remarkable. This means that the vehicle can be better steered due to the kick-down, which can be driven around the cone in a more preferred manner, and obstacles are better avoided. 19 a) is more clearly shown in b) of FIG. 19, which b) shows the transverse displacement of the vehicle with respect to time. The kick-down simulation here exhibits excellent steering characteristics, which allows better control of the vehicle than simulation without kick-down.

20 a) to d) show the wheel speed versus time of the wheels from the front left to the rear right, with kick-down having no effect on the waveform on the wheel speed. Unfavorable acceleration of the vehicle is virtually impossible.

In FIG. 21, a curve of pitch angles suitable for being simulated in the drive simulation is shown in FIG. 21 a) over time. The pitch angle here is shown to be relatively smooth and steady in the case of a kick-down simulation, so that the vehicle is well controlled. In a similar manner the pitch rate is reproduced in b) of FIG. The operating state of the vehicle will be inherently good in the case of simulations following kick-down.

As shown in FIG. 9, the contact force (Newton) with respect to time (seconds) is again reproduced in FIG. 22, a) of FIG. 22 is for the front left wheel, and d) of FIG. 22 is for the rear right wheel. It is about. According to this illustration, in the case of a kick-down simulation (thin or relatively weakly provided curves), a fairly high contact force (thick or relatively dark curve) on the front wheel without kick-down can be intentionally reduced. Thus, the wheel will not significantly deviate from the critical transmission range. In conclusion, a substantially high braking force can be transmitted. In addition, as configured in b) of FIG. 22, the increase in contact force at the second maximum value of approximately 300 Newtons is formed higher than without the kick-down, so that an average value of the braking force that can be transmitted can be obtained. In addition, as clearly shown in c) and d) of Figure 22, relatively high braking forces can be transmitted on the rear axle, and the deliverable braking and contact forces are averaged out so that they are relatively on the outer side of the curve. Excellent braking reaction force can be realized.

This effect on the transmissible lateral force is clearly shown in Figs. 23 a) to d) for the rear right wheel at the front left wheel. As can be appreciated from b) of FIG. 23, the lateral force of approximately 300 Newtons would be better transmitted to the front right wheel with the first rise of the lateral force in the simulation following the kick-down than without the kick-down. Can be. The same applies to the rear right wheel, and a transverse force of approximately 300 Newtons or more can be transmitted. This results in a more stable and safe driving state.

Additional exemplary states are shown in FIGS. 23-30. Here the simulation is driven at a speed of 100 km / h on the right turn curve, simulations without kick-down are shown as thick or dark lines, and simulations following kick-down are shown as narrow or blurry lines.

Thus, in FIG. 24 (as in FIGS. 6 and 18), in FIG. 24 a) the reference velocity (km / h) is plotted against time, and in FIG. 24 a) the driving moment Nm is time. Shown graphically for (seconds). Here, a kick-down is formed at approximately 1.94 seconds from the start of the simulation, and the driving moment of the engine soars from less than 50 Newton meters to more than 250 Newton meters, and then from approximately 250 Newton meters after approximately 0.3 to 0.4 seconds. Plunges back to 50 Newton meters.

In Figure 25a) the yaw rate is reproduced over time. 25B shows longitudinal acceleration over time. 25 c) shows the lateral acceleration over time. In FIG. 25 d), the attitude angle is shown graphically over time.

As shown in FIG. 7 and FIG. 20, the speed of the wheel from the front left wheel to the rear right wheel is shown in FIGS. Here, the wheel speed does not substantially deviate from the speed of other wheels, and is consistent with the simulation following the kick-down (relatively thin and blurry lines) and for the simulation without kick-down (relatively thick and thick lines). Due to kick-down, changes in vehicle speed may not usually be considered when driving on curves and other operating states.

As shown in Fig. 10, the braking pressures for the two simulated states without kick-down and following the kick-down are shown in Figs. 27 a) to d) from the front left wheel to the rear right wheel. The kick-down process and the initiation of full braking are clearly shown in accordance with a) to d) of FIG. 27 above, with substantially high braking pressures being implemented in the rear wheels for simulations following kick-down rather than without kick-down. Can be.

28 a) shows the pitch angle over time, with the kick-down being formed approximately 1.94 seconds from the start of the simulation, a relatively slowed waveform of the pitch angle formed and the amplitude flattened as well The frequency is smoothed. The same applies to the pitch ratio shown in b) of FIG. 28. The state in FIG. 28 is similar to the state shown in FIGS. 8 and 21, which is associated with a qualitatively positive evaluation of the simulation following the kick-down at any rate and surprising possibilities, thus lowering the vehicle to the front wheels. Dynamic movement of the axle load is canceled when driving and braking on the curve by kick-down or significant combustion of the gas.

The contact force from the front left wheel to the rear right wheel is shown in Figures a) to d) of FIG. In the case of the front left wheel, an increase in contact force of 200 Newtons is recorded in the center portion of the waveform on the outside. For the front right wheel, a decrease of 300 Newtons is recorded in the center portion of the waveform on the inside. In the case of the rear left wheel, the contact force of 800 Newtons is increased on the outer wheel at the center portion of the corrugation, so that the rear right wheel has an increase of at least 150 Newton meters on the inner side as shown in d) of FIG. . This means that the rear right wheel is lifted off without kick-down in this state, and this wheel has a good grip on the road so that the force can be transmitted. The state shown in FIG. 29 is qualitatively similar to the state shown in FIG. 9 as well as the state shown in FIG.

The lateral force of the wheel from the front left wheel to the rear right wheel is shown in Figures 30 a) to 30 d). Here, as clearly shown, in the case of a kick-down simulation, an increase of 400 Newtons of transmissible lateral force is recorded at the front left wheel. For the front right wheel, an increase in the transmissible lateral force of 200 Newton meters is recorded. An increase in the transmissible lateral force of 400 Newtons in the rear left wheel can be formed, and an increase in the transmissible lateral force of 200 Newtons in the rear right wheel can be recorded. Thus, in the absence of a kick-down simulation, the transmissive lateral force, which is formed to be virtually zero, is converted into a transmissive lateral force of at least 200 Newtons.

24 to 30 are driven to the right side of the curve at a speed of 100 km / h and a sudden onset of full braking is formed and dynamics of the axle load when the vehicle is lowered to the front wheels by the method according to the invention At least a partial offset of transmission can be formed by deliberate triggering of kick-down or by providing a stroke to the accelerator, whereby a practical maximum level of engine torque is forcibly required. As a result, the driving state is substantially improved. The vehicle is more controllable. Manipulation is relatively simplified. It can be better overcome in dangerous situations.

Therefore, the lateral turning force on the rear axle substantially affects the stability of the vehicle. The wheel's contact force characteristic curve for lateral turning force shows a steep upward slope in the range of wheel contact forces formed in the rear axle. That is, the lateral turning force is greatly changed due to the small change in the wheel contact force. Therefore, a relatively large lateral turning force can be formed due to the cancellation of the dynamic transmission of the axle load during braking on the curve, so that the vehicle has a relatively large stability when braking on the curve. In addition, the oversteering reaction of the vehicle (depending on possible rolling or skidding) can be reduced using the method described above.

In conclusion, in the case of the state mentioned in FIG. 8, the pitch angle (°) with respect to time (seconds) is shown in FIG. 31. The relatively thin and blurry line “A” shows the waveform of the pitch angle without kick-down. The thick and dark line “B” shows the waveform of the pitch angle in the case of kick-down that can be accurately generated at the time of presentation. The thin or relatively blurred dashed line "C" shows the waveform of the pitch angle formed in 0.1 second for kick-down after the point of braking. In conclusion, the medium dashed line “E” shows the waveform of the pitch angle for the kick-down case formed 0.3 seconds after the point of braking, from which the kick-down actively affects the waveform of the pitch angle. As a result, the amplitude becomes flat and the waveform smoothes and disappears more quickly In addition, as can be seen from Figure 31, for example, from 0.05 seconds to 1.5 seconds, preferably approximately 0.1 seconds from the time the braking is applied. If -down occurs, the waveform of the pitch angle is particularly well formed and significantly improved in contrast to the braking process which can be obtained without kick-down.

The present invention thus provides a method of at least partially canceling the dynamic movement of the axle load when a portion of the differential load is carried on one or more front wheels. The need for drive moment is also used for the purpose of offsetting. Drive moments are required for fully provisioned operation when fully braked and for unstable drive on the curve when driving on the curve. The invention furthermore aims at the use of a control device and a microprocessor for carrying out the method according to the invention. In addition, the indicated driving concept is equipped with a microprocessor or a control device. In conclusion, mention is made of software for performing the method. Thus, a vehicle for providing a method according to the invention is equipped with a care device or microprocessor for performing software.

Claims (19)

12. A method for at least partially canceling the dynamic transfer of axle loads in a vehicle, the method of claim 1, wherein the drive moment is increased or decreased without substantially changing the speed of the vehicle for offsetting. 2. The method of claim 1 wherein an accelerator stroke is provided to increase the drive moment. The method according to claim 1 or 2, characterized in that a requirement for the driving moment during the full braking operation, ie preferably the accelerator stroke, is provided in order to offset the forward forward dynamic transmission of the axle load when performing the full braking operation. How to. 3. The method according to claim 1 or 2, characterized in that the demand of the driving moment when driven in the curve, i.e. is preferred, to offset the obliquely forward and / or transversely directed dynamic transmission of the axle load when driven in the curve. Accelerating stroke is provided. The method of any one of claims 1 to 4, wherein the method is E.g. Electronic Stability Program (ESP), Electro-Hydraulic Power Steering System (EHPS), Electronic Power Steering System (EPS or EPAS), Electronic Damping Regulation Process (CDC) ), Integrated chassis control system (ICC), such as a brake assistant, interactive dynamic driving system (IDS), understeer control logic or the like. Situation dependent chassis regarding the effective stability of the vehicle transmitted by the sensors for the current state of the vehicle for the process of controlling the driving stability system or parts thereof that function within the framework of the vehicle, Evaluating the items of braking and / or steering data, Determining the critical state of the vehicle and / or the state of the vehicle requiring adjustment with the aid of useful data, Defining the magnitude of the driving moment required to offset the axle load distribution, Defining the duration of the driving moment required to offset the axle load distribution, and Initiating the required drive moment using a pre-determined scale and a predetermined duration by applying an appropriate requirement. 6. A method according to any one of claims 1 to 5, wherein the complete braking operation is performed with the support of ABS. 7. A method according to claim 6, wherein the presence of a complete braking action is determined by detection of an ABS flag indicating when the brake is provided with a pressure of the master cylinder or a gradient of the pedal. 6. A method according to any one of claims 1 to 5, wherein the presence of a complete braking action is determined by a process of sensing the angle setting of the brake pedal corresponding to the brake pedal fully depressed. 6. The method according to any one of claims 1 to 5, wherein the presence of a critical state or the complete braking action when driving in the curve is determined by obtaining the value of the data from the ESP. 10. The method according to any one of claims 1 to 9, wherein the increase in drive moment in the critical state or when braking is applied when driving on the curve is by kick-down or 250 ms to 750 ms, preferably 300 ms to 500 and initiated by a pulse of maximum power with a duration of ms. 11. The method according to any one of claims 1 to 10, wherein the increase in drive moment is -0.5 seconds to +1.0 seconds, preferably -0.01 seconds to +, obtained for the time when braking is applied, which is a zero time point. A pulse or kick-down of maximum power in a time window of 0.5 seconds, most preferably +0.05 seconds to +0.25 seconds. 12. The method according to any one of the preceding claims, wherein the increase in drive moment is implemented in a pulsed manner by a pulse or kick-down of maximum power from an increase in pulse or accelerator stroke or a plurality of drive moments. Characterized in that the method. 13. A method according to claim 12, wherein the increase in drive moment, accelerator stroke or pulse of maximum power each has a duration of 50 ms to 150 ms, preferably 100 ms, respectively. 14. A drive moment as claimed in any one of the preceding claims, wherein a drive moment of at least 250 Nm, preferably a drive moment of at least 270 Nm, is requested by an increase in drive moment, preferably by a pulse of maximum power or accelerator stroke. (request) characterized in that. A microprocessor for performing the method according to claim 1. A control device for carrying out the method according to any one of claims 1 to 14. A vehicle drive, preferably an internal combustion engine, comprising a microprocessor according to claim 15 and / or a control device according to claim 16.  Software for performing a method according to any one of claims 1 to 14. A control device comprising a microprocessor according to claim 15, which performs a method according to claim 1, executes software according to claim 18, and according to claim 16. Vehicle comprising a.

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