Vehicle dynamics are adjusted by using dampers.

Abstract

The present invention relates to a method for adjusting the driving dynamics of a vehicle (1) by means of a damper (16), wherein the vehicle (1) includes at least two axles (10, 12), each axle having at least two wheels (14) together with a damper (16), and wherein the method comprises the following adjustments: a) obtaining a driving dynamics theoretical parameter (SD); b) determining an adjustment deviation (e) based on the driving dynamics theoretical parameter (SD) and the driving dynamics actual parameter (ID); c) changing the damper force (D) of at least one damper (16) according to the adjustment deviation (e); d) updating and feeding back the driving dynamics actual parameter (ID) when the damper force (D) changes, to determine the adjustment deviation (e) again. Furthermore, the present invention relates to a vehicle (1) and an adjustment device (20) for the vehicle (1).

Description

Technical Field

[0001] This invention relates to a method for adjusting the driving dynamics of a vehicle, particularly a motor vehicle (such as a passenger car or a truck). The driving dynamics adjustment is performed via dampers at the vehicle wheels. In particular, the lateral dynamics of the vehicle and, especially, yaw characteristics and, particularly, wavy-yawing moments, can be adjusted. Furthermore, this invention relates to a vehicle and adjusting device having or providing such driving dynamics adjustment. Background Technology

[0002] It is known that vehicle wheels are connected by means of dampers, which support the wheels on the vehicle body. The dampers generate damping forces that affect the forces acting between the vehicle wheels and the roadway.

[0003] Furthermore, it is known that so-called adjustable or adaptive dampers are configured, in which the damping force generated can be variably adjusted during driving. For example, the driver can select a damping characteristic from several options, such as sporty or comfortable damping. Depending on the driving conditions, the damping force to be generated is determined based on this selection and adjusted accordingly. However, this adjustment is limited to correctly achieving the preset damping force through the individual dampers. For example, within the scope of this adjustment, it is ensured that the preset current change of the damper or other operating parameters (which should be adapted to generate the desired damping force) are actually achieved. The damping force to be adjusted is typically determined based on characteristic curves, which can obtain the vehicle's body sensor driving dynamics parameters as input parameters.

[0004] Further background on the corresponding damper system is obtained in DE 10 2018 203 182 A1. Furthermore, DE 10 2018 203 182 A1 discloses a solution for influencing the lateral dynamics of a vehicle, and more specifically, a solution for generating yaw moment by means of an adaptive damper. In particular, according to the teachings of Figure 4 there, the damper force affects the resulting wheel load due to the roll motion of the vehicle body, thereby adjusting the lateral force transmitted through the wheels. Furthermore, in conjunction with the [further details omitted]... Figure 2 As shown, by using dampers to specifically distribute wheel loads to different vehicle wheels, the overall lateral force at the vehicle wheels can be maximized. This improves driving stability.

[0005] However, it has been shown that there is still potential for improvement in this or other effects on driving dynamics and, in particular, lateral dynamics. This is especially true within the limits of driving dynamics. Summary of the Invention

[0006] Therefore, the purpose of this solution is to improve the reliability and effectiveness of driving dynamics effects by utilizing the vehicle's dampers.

[0007] This objective is achieved through the technical solution according to the present invention. The present invention has several advantageous improvements. Unless otherwise stated or obvious, all the above descriptions, features, and improvements are also applicable to or incorporated into this solution.

[0008] It is known that, especially within the limits of driving dynamics, the effect of a damper on driving dynamics can only be modeled or predicted in a limited way. Therefore, previous methods cannot always reliably influence driving dynamics in the desired manner. Therefore, the solution disclosed herein is set up to adjust the dynamic parameters to be affected and uses the damper as an adjustment element for this purpose.

[0009] This differs from previous approaches, where dynamic parameters, such as characteristic curves, were used solely to determine the damper force (also referred to here as damping force) that should be adjusted by the damper. Here, it is generally assumed that a fixed or universally valid relationship exists between the damper force and the dynamic parameters. Therefore, it is considered sufficient to control the damper force that should be adjusted by pre-setting it, without separately detecting and considering its actual effect on ride dynamics. It is now known that this fixed relationship between damper force and dynamics is not always applicable, especially within the limits of ride dynamics, and is generally difficult to model.

[0010] The solution disclosed herein enables the checking or assurance by adjusting the command parameters. In this sense, the theoretical dynamic parameters preset are actually realized by the vehicle's adaptive dampers. Therefore, the actual dynamic parameters, adjusted due to the adaptive damping force, can be determined. The actual dynamic parameters can be subtracted from the theoretical dynamic parameters to determine the adjustment deviation. This adjustment deviation can be used to determine and / or update the adjustment parameters realized by the dampers. This corresponds to forming an adjustment loop (Regelschleife), the purpose of which is to adapt the actual dynamic parameters to the theoretical dynamic parameters by using the dampers as an adjustment link.

[0011] Generally, the solution disclosed herein is configured to determine the deviation between theoretical and actual driving conditions (especially theoretical and actual dynamic parameters), and adjust the vehicle's dampers accordingly to reduce this deviation. Thus, driving stability can be improved, especially if the theoretical dynamic parameters provide a corresponding increase in stability or have already been determined for this purpose.

[0012] In particular, a method is proposed for adjusting the driving dynamics (especially lateral dynamics and, more particularly, yaw characteristics) of a vehicle by means of (especially adaptive, adjustable, and / or controllable) dampers (which are, for example, adjusted to generate roll and yaw moments), wherein the vehicle comprises a plurality of wheels (especially at least four), each wheel being connected to a damper (and thereby supported, for example, at the vehicle body). More specifically, the vehicle comprises at least two axles (especially a front axle and a rear axle), each axle having at least two wheels and (connected thereto) dampers (preferably one damper for each wheel). The method here has the following adjustment, or in other words, forms the following adjustment loop:

[0013] a) Obtain theoretical parameters for driving dynamics;

[0014] b) Determine the adjustment deviation based on or on the theoretical parameters of driving dynamics and the actual parameters of driving dynamics;

[0015] c) Change the damper force (or additional damping force) of at least one damper according to the adjustment deviation;

[0016] d) When the damper force changes, (especially update and) feed back the actual driving dynamics parameters to re-determine the adjustment deviation.

[0017] Due to the change in damper force, the actual parameters of the driving dynamics that are fed back have values ​​that change according to expectations, meaning that they do not correspond to the actual parameters on which the previously determined adjustment deviation was based.

[0018] The re-determination of the adjustment deviation may include, or require, the re-implementation of measures a), but at least measures b) and c). This can be repeated multiple times until the adjustment deviation becomes zero, and preferably until the driving dynamics adjustment is deactivated. In particular, it can be configured to activate the driving dynamics adjustment over a longer period of time, and to continuously and / or repeatedly implement the above sequence. Specifically, the theoretical driving dynamics parameters can be repeatedly updated here, and calculations can be performed using the fed-back actual driving dynamics parameters to determine the adjustment deviation.

[0019] Obtaining the theoretical parameters of driving dynamics may also include determining the parameters. However, this determination can also be performed separately (e.g., by a separate unit and / or generally in addition to the method claimed), and the parameters can be transmitted or output as the final result of the determination and thus obtained. To determine the theoretical parameters of driving dynamics, characteristic maps or vehicle models can be used, as also mentioned, for example, in DE 10 2018 203 182 A1 (see

[0021] in the case of additionally using the steering angle as an input parameter).

[0020] It goes without saying that the theoretical and practical parameters of driving dynamics preferably refer to similar driving dynamics parameters. Generally, this driving dynamics parameter can be a lateral dynamics parameter. According to one example, the driving dynamics parameter is the slip angle (Schwimmwinkel). According to another example, it is the yaw rate. Alternatively, the time derivative of any exemplary driving dynamics parameter mentioned herein may also be considered.

[0021] The relationship between driving dynamics parameters or current adjustment deviations and the damper force to be adjusted can be defined according to any known method in the prior art. For example, characteristic curves or computational models can be stored for this purpose. The relationship described is known from DE 10 2018203182A1, according to which the wheel lateral force can be adjusted via the damper force, and this can then, for example, affect the yaw characteristics or yaw rate as a dynamic parameter of the vehicle.

[0022] The relationship between damper force and oversteer or understeer is also described below as another example, where oversteer or understeer also corresponds to driving dynamics parameters, or can be determined based on driving dynamics parameters.

[0023] As described above, the damper can have its own adjustment or adjustment loop to change the damper force. In particular, the damper force can be obtained and / or preset as a theoretical parameter to be adjusted. Subsequently, this damper force can be ensured to be actually achieved by adjusting the internal damper and / or, for example, by adapting electrical operating parameters. The adjustment speed or frequency of the damper can here be higher than the adjustment speed of the driving dynamics or the adjustment speed of the aforementioned upper-level adjustment loop.

[0024] In summary, the adjustment of the damper force by the damper can therefore be embedded into the higher-level driving dynamics adjustment in a cascaded manner. This improves the reliability and quality in achieving the desired driving dynamics fit.

[0025] Generally, the methods described herein can be implemented in a computer-aided manner. In particular, they can be implemented by means of a regulating device (especially provided by a controller with regulating functions). The regulating functions or regulating loops described herein can be implemented by or defined by algorithms and / or program instructions. These algorithms and / or program instructions can be implemented by the regulating device (especially its processor).

[0026] An improved scheme sets the actual driving dynamics parameters to be measured by sensing and / or determined based on a model. For example, the yaw rate, a driving dynamics parameter, can be determined using a yaw rate sensor. The slip angle, another driving dynamics parameter, is preferably determined computationally based on a model.

[0027] Another implementation is configured such that, in order to change the damper force, theoretical parameters related to the damper force are output to the damper controller (which should change the regulating force of at least one damper). The damper controller preferably provides regulating functions and, in particular, a damper controller itself. This specifically implements the aforementioned variation of the internal damper regulating loop according to a cascaded regulating manner. The damper controller can, for example, be a software module implemented by the damper controller or software functions for manipulating the damper.

[0028] In particular, the theoretical parameter can be the theoretical damper force. The damper controller uses this theoretical damper force, for example, by using characteristic curves, calculation models, or other known methods, to determine the current changes or other operating parameter changes required to control the damper, thereby achieving the theoretical damper force. For adjustment, the actual damper force or actual operating parameters can be fed back.

[0029] Furthermore, it can be configured to change the damper force individually for each wheel. For this purpose, any adjustment or adjustment loop described herein can be implemented individually for each wheel. In particular, the theoretical parameters of the driving dynamics that should be adjusted individually for each wheel can be determined. Alternatively, it can be configured, for example, to determine the damper force that should be adjusted individually for each wheel based on adjustment deviations, in order to reduce those deviations.

[0030] Generally, adjustment parameters can therefore be determined individually for each wheel, but the determination of adjustment deviations and / or theoretical dynamic parameters is not mandatory. For example, the latter can be defined and / or preset with respect to the entire vehicle. To convert or transform adjustment deviations into individual adjustment parameters for each wheel, a computational model can be used, as described, for example, in DE 102018203 182A1, incorporating individual lateral forces for each wheel and their effects on the vehicle's higher-level lateral dynamics.

[0031] One advantage of adjusting each wheel individually is the greater precision when it comes to influencing driving dynamics.

[0032] Alternatively, the damper force can be configured to be varied individually for each axle. This can be understood as determining similar (e.g., percentage or relative) variations or similar (e.g., absolute) adjustments to the damper force for all dampers on the axle, and then implementing them accordingly. However, these damper forces or variations or adjustments may differ from those at other axles.

[0033] One advantage of adjusting each axle individually is the faster adjustment speed when affecting driving dynamics, because the computational cost can be lower compared to a variant that adjusts each wheel individually.

[0034] Driving dynamics parameters can describe a vehicle's understeer or oversteer. In other words, a vehicle's understeer or oversteer can be determined based on driving dynamics parameters. For example, a driving dynamics parameter can be the yaw rate. Therefore, the adjustment deviation can correspond to the yaw rate deviation between the theoretical yaw rate and the actual yaw rate. If this deviation is positive, oversteer may exist. If it is negative, understeer may exist.

[0035] In particular, one improvement is configured to increase the damper force at the front axle and / or decrease the damper force at the rear axle in cases of understeer (i.e., if the driving dynamics parameter is yaw rate and / or the yaw rate deviation of the aforementioned type is negative). This adaptation of the damper force can again be achieved through individual adjustments for each axle. However, it can also be achieved through individual adjustments for each wheel, wherein the damper force is adjusted individually at each wheel of the axle, but individually increased at the front axle and / or individually decreased at the rear axle.

[0036] It has been demonstrated that by appropriately adapting the damper force, understeer can be reliably limited, especially within the limits of driving dynamics.

[0037] Additionally or alternatively, it can be configured to reduce the damper force at the front axle and / or increase the damper force at the rear axle in cases of oversteer (i.e., if the driving dynamics parameter is yaw rate and / or the yaw rate deviation of the type described above is positive). This adaptation of the damper force can again be achieved through individual adjustments for each axle. However, it can also be achieved through individual adjustments for each wheel, wherein the damper force is adjusted individually at each wheel of the axle, but individually reduced at the front axle and / or individually increased at the rear axle.

[0038] It has been shown that by appropriately adapting the damper force, oversteer can be reliably limited, especially within the limits of driving dynamics.

[0039] In another general embodiment, the change in damper force is determined based on the travel speed and / or lateral acceleration. In particular, the damper force can be determined by means of characteristic curves or characteristic diagrams, which are defined based on at least one of the parameters. For example, the damper force to be adjusted can be determined based on the current adjustment deviation, the current travel speed, and / or the lateral acceleration determined by sensing or based on a model. This can again be done individually for each wheel or for each axle.

[0040] The present invention also relates to a vehicle (particularly a motor vehicle and, more particularly, a passenger car or freight vehicle) having: at least two axles (e.g., a front axle and a rear axle), each of the at least two axles having at least two wheels together with dampers (more precisely, each having a damper); and an adjustment device configured to:

[0041] • Determine the theoretical parameters of driving dynamics;

[0042] • The adjustment deviation is determined based on the theoretical parameters and actual parameters of driving dynamics;

[0043] • Based on this, determine and / or output presets related to changes in the damper force of at least one damper (e.g., in the form of new theoretical values ​​of the damper force or presets for changes in the damper force); and

[0044] • When the damper force changes, the adjustment deviation is determined again based on the actual driving dynamics parameters (and in other words, updated accordingly) (e.g., the adjustment and / or the resulting deviation should be adjusted).

[0045] The regulating device can be provided by the controller of a vehicle with corresponding regulating functions. The regulating device may include at least one processor and / or at least one memory device. The memory device may store program instructions that, when executed by the processor, cause the regulating device to provide any of the functions, operating states, or measures described herein.

[0046] Generally, vehicles and, in particular, their regulating devices may include any additional features to provide all the operating states, functions, and effects described herein. In particular, all interpretations and modifications of the method features may also be applied to the same or similar features of the vehicle and, in particular, its regulating devices, or to features installed in the vehicle. Generally, vehicles and, in particular, their regulating devices may be configured to implement methods according to any aspect described herein.

[0047] The present invention also relates to an adjustment device for a vehicle according to the foregoing aspects. Attached Figure Description

[0048] The embodiments of the present invention are explained below with reference to the accompanying schematic diagrams.

[0049] Figure 1 The schematic diagram illustrates the driving dynamics adjustment of a vehicle according to an embodiment.

[0050] Figure 2 A flowchart of a method according to an embodiment is shown, which consists of Figure 1 This is implemented through vehicle or its driving dynamics adjustments. Detailed Implementation

[0051] Figure 1An exemplary vehicle 1 is shown in a highly simplified side view. The vehicle 1 includes a front axle 10 and a rear axle 12. Two vehicle wheels 14 are arranged at each of the front axle 10 and the rear axle 12, and one of the vehicle wheels on each axle 10, 12 is obscured in the view shown.

[0052] The vehicle wheels 14 are connected to adaptive dampers 16 of a conventional structure. More specifically, they are connected to and supported on the vehicle body via the dampers 16. Not shown, the dampers 16 are embedded in a spring-damper system.

[0053] Each damper 16 has a damper controller 18. The damper controller 18 provides adjustment functions or forms a damper controller. The damper controller is configured to adjust and preferably regulate the theoretical damper force obtained for the damper 16 in relation to it by adapting the electrical parameters of the damper 16 and, in particular, by current variation.

[0054] Furthermore, an adjustment device 20 for vehicle 1 is shown. This adjustment device may be provided by or implemented as a digital and / or electrically operable controller. The adjustment device 20 is connected to the damper controller 18 of each damper 16 via data lines and preferably via a communication bus not shown separately.

[0055] An enlarged schematic of the control loop or control circuit implemented by the control device 20 is shown. Thus, the control device 20 obtains (or preferably determines) the theoretical dynamic parameter SD. For example only, it is currently the yaw rate of vehicle 1, which can be determined, for example, by means of a conventional model-based approach.

[0056] Furthermore, the regulating device 20 also obtains or preferably determines the actual dynamic parameter ID, which, in the case shown, is the yaw rate of vehicle 1. This yaw rate can be determined by sensing using a yaw rate sensor 22 connected to the regulating device 20.

[0057] The adjustment deviation e is determined by the difference between the theoretical dynamic parameter SD and the actual dynamic parameter ID. Since the driving dynamic parameter under consideration is the yaw rate, the adjustment deviation e corresponds to the yaw rate deviation. This yaw rate deviation describes understeer or oversteer by its conformity in the manner described above, and is reduced by the adjustment device 20 within the scope of driving dynamics adjustment.

[0058] The adjustment deviation e is supplied to the adjustment parameter determination function 24. The adjustment parameter determination function 24 describes the relationship between the adjustment parameter (in this case, the damper force) and the adjustment deviation e, particularly in such a way that changes or values ​​of the adjustment parameter can be determined to reduce the adjustment deviation e. This relationship can again be defined or determined based on the model. The relationship between the yaw rate and the damper force exists in the manner described above, for example, through the lateral wheel force generated by the damper force, which affects the yaw characteristics, especially when the vehicle 1 rolls.

[0059] In the example shown, the adjustment parameters are determined individually for each axle. More precisely, for each axle 10, 12, the relative change or a new theoretical value of the damper force D that should be made in the damper 16 there is determined to reduce the adjustment deviation e. This relative change and theoretical value are examples of presets related to the desired or required change of the damper force D generated by the adjustment device 20.

[0060] When determining the adjustment parameters, first determine whether the adjustment deviation e currently indicates oversteering or understeering, which can be done by checking its sign as described above. Subsequently, any variation in the damper force D for each axle can be preset to reduce oversteering or understeering, as explained above in the general description section.

[0061] Not shown separately, vehicle speed or lateral acceleration may also be considered within the range determined by the adjustment parameters. These parameters can be obtained by the adjustment device 20 from existing sensors in the vehicle 1.

[0062] As illustrated, the required change in damper force D (the absolute theoretical value of damper force D alternatively) is output to damper controller 18. For illustrative purposes only, only damper force D and damper controller 18 are shown in the control diagram. The damper controller 18 for the dampers 16 of the common axles 10, 12 receives the same preset from the adjustment parameter determination function 24 due to the individual changes for each axle.

[0063] The damper controller 18 preferably adjusts the damper force D or its variation within the framework of its own adjustment loop, for example, by adapting and, in particular, adjusting the corresponding damper flow. This affects the driving dynamics characteristics of the object being adjusted, which in the present case is vehicle 1. The driving dynamics characteristics are obtained here from the actual dynamic parameter ID. The latter is continuously updated in a conventional adjustment manner, and therefore also after the changed damper force D is adjusted by means of the damper controller 18. In this way, the effect of the change in damper force D on the adjustment deviation e can be continuously determined, and the adjustment deviation e can be reduced by continuously adapting and readjusting the damper force D.

[0064] Overall, this achieves the adjustment of the driving dynamics of vehicle 1 and, in the example shown, the adjustment of the vehicle's yaw characteristics, wherein the damper 18 is used as an adjustment element, and the resulting damper force D or its variation is used as an adjustment parameter. Unlike the prior art, here, by means of adjustment checks and ensuring the fit of damping characteristics, the desired effect on driving dynamics is actually achieved.

[0065] Figure 2 A flowchart of the method implemented by vehicle 1 in the manner described is shown. Within the scope of measure M1, the theoretical dynamic parameter SD is obtained and / or determined. Within the scope of measure M2, the adjustment deviation e is determined based on the theoretical dynamic parameter SD and the actual dynamic parameter ID, preferably measured by sensing.

[0066] Within the scope of measure M3, the change in damper force D is determined as an adjustment parameter to reduce the adjustment deviation e. Within the scope of measure M4, these damper forces D are adjusted individually by the damper controller 18. As measure M5, the actual dynamic parameter ID for this adjustment is determined, or the current value of the actual dynamic parameter ID is determined. Furthermore, the actual dynamic parameter ID is fed back so that when measures M1-M5 are experienced again, it is considered as a new or current actual dynamic parameter ID within the scope of measure M2 to determine the adjustment deviation e. Preferably, measure M1 is repeated only if the theoretical dynamic parameter SD changes. Generally, this adjustment loop can be repeated until the driving dynamics adjustment is discontinued.

[0067] List of reference numerals

[0068] 1 vehicle

[0069] 10 Front axle

[0070] 12 Rear Axle

[0071] 14 Vehicle wheels

[0072] 16 Dampers

[0073] 18 Damper Controller

[0074] 20. Adjustment equipment

[0075] 22 Yaw rate sensor

[0076] 24. Adjusting parameters to determine the function

[0077] SD Theoretical Dynamic Parameters

[0078] ID Actual dynamic parameters

[0079] e. Adjustment deviation.

Claims

1. A method for ride dynamics adjustment of a vehicle (1) by means of dampers (16) only, wherein The vehicle (1) comprises at least two axles (10, 12) which each have at least two wheels (14) which each have a damper (16), and wherein the method has the following steps: a) obtaining a driving-dynamics theoretical variable (SD); b) determining an adjustment deviation (e) from the driving-dynamics theoretical variable (SD) and a driving-dynamics actual variable (ID); c) changing a damper force (D) of at least one damper (16) as a function of the adjustment deviation (e); d) updating and feeding back the driving-dynamics actual variable (ID) as the damper force (D) is changed, in order to determine the adjustment deviation (e) again, characterized in that in the case of understeering, the damper force (D) is increased at the front axle (10) and / or reduced at the rear axle (12), and in the case of oversteering, the damper force (D) is reduced at the front axle (10) and / or increased at the rear axle (12).

2. The method according to claim 1, characterized in that, The driving-dynamics actual variable (ID) is measured in a sensoric manner and / or determined on the basis of a model.

3. The method according to claim 1 or 2, characterized in that, In order to change the damper force (D), a theoretical variable which is related to the damper force (D) is output to a damper controller (16).

4. The method according to any of the preceding claims 1 to 2, characterized in that, The damper force (D) is changed individually for each wheel.

5. The method of any one of claims 1 to 2, wherein, The damper force (D) is changed individually for each axle.

6. The method according to any of the preceding claims 1 to 2, characterized in that, The change in the damper force (D) is dependent on the driving speed and / or the lateral acceleration.

7. An adjustment device (20) which is set up to carry out the steps of the method according to any one of the preceding claims 1 to 6.

8. A vehicle (1) with at least two axles (10, 12) which each have at least two wheels (14) which each have a damper (16); and with an adjustment device (20) according to claim 7.

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