Determination of a possible delay size

Abstract

Method for determining a possible deceleration value of a braking system of a vehicle (10), wherein the braking system comprises at least one brake (1), the method comprising the following steps: - Providing a possible manipulated variable amount that corresponds to an actual manipulated variable amount that can be set by the braking system, wherein the at least one brake (1) is designed to generate a deceleration variable in response to a manipulated variable of this actual manipulated variable amount; - Providing a brake system model which is designed to determine a deceleration value of the at least one brake (1) from an input manipulated variable amount; - Entering the possible manipulated variable amount into the braking system model; - Determining a possible deceleration value of the at least one brake (1) corresponding to the possible manipulated variable amount by means of the brake system model.

Description

[0001] The present invention relates to a method for determining a possible delay value as well as a device, a vehicle, a computer program product and a storage medium for carrying out the method.

[0002] The development of electrically powered vehicles and the associated possibility of achieving a braking effect on the vehicle by means of generator operation of the electric drive motor has opened up approaches to eliminating the need for conventional continuous braking devices, such as retarders. Due to the limited storage capacity of the corresponding electrical energy storage devices and the associated limited recuperation and thus braking capability, legal regulations have been enacted or are being developed according to which the driver, particularly in the commercial vehicle sector, must be informed about the braking performance of their vehicle, with particular emphasis being placed on the mechanical brake. This is used at the latest when a continuous braking function is no longer available, e.g. via generator operation of the electric drive motor.In particular, efforts are being made to inform the driver about the maximum possible deceleration of the vehicle. However, regardless of this, i.e., also for other types of road vehicles, such as conventionally or hybrid-powered vehicles, there is a need to be able to determine braking performance as accurately as possible, both to be able to react during a driving situation and to organize maintenance measures more effectively, especially more economically.

[0003] Today's vehicles offer the option of roughly determining brake pad wear. For example, the total wear of a disc brake—that is, the combined wear of both pads and the disc—is monitored. This is done either by using a potentiometer that responds as soon as pad wear has advanced sufficiently, or by using a continuous potentiometer whose signal also allows conclusions to be drawn about the wear progression before complete wear. Alternatively, a sliding contact can be used; this contact responds when it has been exposed due to wear.

[0004] From US 2021 / 0 192 959 A1, a method is known that uses actual braking operations to determine the possible deceleration magnitude.

[0005] It is not possible to determine a possible deceleration value, for example a braking torque, or a possible vehicle deceleration without actually having recourse to braking operations.

[0006] Therefore, it is an object of the present invention to solve this problem.

[0007] This problem is solved by the subject matter of the independent claims. Advantageous further developments are the subject matter of the dependent claims.

[0008] For the purposes of this application, a possible variable, such as a possible manipulated variable, a possible deceleration variable, or a possible vehicle deceleration, is understood to be a variable whose magnitude can just be achieved by the system, actuator, or the like under consideration. This means the currently available range of values, or specifically, a specific value within that range that the corresponding variable can assume.

[0009] For the purposes of this application, a trailer is understood to mean any possible form of trailer. In particular, a trailer can include a semi-trailer or a drawbar trailer. A towing vehicle can be a vehicle that can pull a trailer under its own power. However, it can also be a vehicle that is itself towed and can simultaneously pull another trailer. In particular, this can be a dolly or a trailer designed to be coupled to another trailer.

[0010] According to the invention, a method is provided for determining a possible deceleration value of a braking system of a vehicle, wherein the braking system comprises at least one brake, the method comprising the following steps: - Providing a possible manipulated variable amount corresponding to an actual manipulated variable amount that can be provided by the braking system, wherein the at least one brake is designed to generate a deceleration variable in response to a manipulated variable of this actual manipulated variable amount; - Providing a brake system model which is designed to determine a deceleration value of the at least one brake from an input manipulated variable amount; - Entering the possible manipulated variable amount into the brake system model; and - Determining a possible deceleration value of the at least one brake corresponding to the possible manipulated variable amount by the brake system model.

[0011] This determines the deceleration rate achievable with a specific control variable. A braking system model is used for this purpose, which maps the behavior of at least one of the vehicle's brakes to an actual control variable with the corresponding control variable magnitude.

[0012] Preferably, the deceleration variable is a braking torque or a braking force generated by the at least one brake in response to the manipulated variable.

[0013] Preferably, the possible manipulated variable value includes a maximum possible manipulated variable value. This has the advantage that a maximum possible deceleration value can be determined. This means that a statement can be made at any time about how strong or efficient the respective brake is or is currently.

[0014] The possible deceleration value is thus determined by taking into account a control variable that can be set during operation. This means that if the braking system is technically limited during operation, for example because an actuator for actuating the brake is defective, it can be taken into account that a lower deceleration value can be achieved due to the limited control variable. In addition, the braking system model can take into account which deceleration value can be set using the possible control variable, i.e. which deceleration value is achievable. If a deterioration, or generally a change, in the condition of the brake is taken into account with the braking system model, then a possible, i.e. an achievable, deceleration value can be determined using the present method.

[0015] The braking system model is preferably designed to take the state of the brake into account by considering input variables from the vehicle. This allows a mapping of a manipulated variable or a manipulated variable amount to a corresponding deceleration variable, wherein this mapping occurs according to the state of the at least one brake. If, for example, a temperature of the at least one brake is determined by the vehicle by measuring it or determining it using a model, the braking system model can take into account a change in the physical properties, in particular a change in the mapping of the manipulated variable or manipulated variables to the deceleration variable. In this way, a determination of possible deceleration variables, in particular a determination of a maximum deceleration variable, can be taken into account by the braking system model.

[0016] A further input variable can be provided by entering a wear variable of the at least one brake. This can be, as described below, a travel distance and / or an actuation angle. In particular, it can be taken into account when these variables reach a maximum value, which indicates increased wear.

[0017] The possible manipulated variable preferably comprises an amount of a contact pressure force, a clamping force, an actuator force, an actuator pressure, an actuator current and / or an actuator voltage. A contact pressure can generally describe the strength of pressing a friction element against a corresponding counterpart. A clamping force can describe the strength of clamping the brake elements of a brake caliper against a brake disc. An actuator force can describe the force of an actuator that is designed to introduce this actuator force into the braking system. Such an actuator is preferably fluidically, i.e. in particular pneumatically or hydraulically, or electromechanically actuated. Accordingly, an actuator pressure, i.e. a fluidic pressure, or an actuator current or an actuator voltage can also be regarded as a manipulated variable.

[0018] The braking system or the at least one brake preferably comprises a fluidically, in particular pneumatically or hydraulically, and / or an electromechanically actuated brake.

[0019] Preferably, the at least one brake of the braking system comprises a friction brake. A friction brake can, in particular, be a drum or disc brake. By determining the potential deceleration of this brake, a statement can be made, for example, about a possible braking torque generated by the brake.

[0020] The braking system model preferably includes a temperature, in particular of the brake, a travel distance and / or an actuation angle as further input variables. In this way, the possible deceleration value can be determined by the braking system model as a function of a temperature, in particular a temperature of friction elements of the brake such as brake pads and / or a brake disc. By taking a travel distance and / or an actuation angle into account in the braking system model, the determination of the possible deceleration value can be improved and / or a statement about brake wear can be made. Brakes subject to wear are actuated by translational and / or rotational mechanisms, in particular transmission mechanisms, and / or actuators. If wear increases, this results in larger travel distances and / or actuation angles. These can be recorded, whereby a statement about wear can be made.If the mechanisms or actuators have adjustment devices designed to at least partially compensate for the influence of wear on the travel and / or actuation angle, it is also conceivable to determine the wear by detecting this adjustment, i.e., in particular, by the amount by which the travel and / or actuation angle has been adjusted. Considering the travel and / or actuation angle may also include considering when wear has progressed to the point where a stop is reached and / or the travel and / or actuation angle assume a maximum permissible value.

[0021] The method preferably comprises a step in which the determined possible deceleration value is compared with a limit value. The limit value can, for example, be constant or variable. If it is determined that the possible deceleration value does not reach the limit value, it must be concluded that the condition, in particular the wear condition, of the at least one brake is no longer optimal. For example, maintenance of the brake can then be scheduled. If a maximum deceleration value is determined with a maximum possible manipulated variable, and this maximum deceleration value does not reach the corresponding limit value, this represents a safety-critical problem, which may also require countermeasures during travel. For example, a stop of the vehicle can be forced.

[0022] Alternatively or additionally, the method comprises a step in which a possible vehicle deceleration is determined from the determined possible deceleration value. Furthermore, this possible vehicle deceleration can be compared with a corresponding limit value. This limit value can, for example, be constant or variable. The above considerations apply analogously here as well. If, in particular, it is determined that the maximum possible vehicle deceleration falls below a limit value, a safety-critical problem exists, which may also require countermeasures during the journey. For example, a forced stop of the vehicle can be necessary.

[0023] Depending on the result of the evaluation of the possible deceleration magnitude and / or the possible vehicle deceleration, a warning may also be issued to the driver.

[0024] Preferably, the limit value and / or the possible vehicle deceleration are / is determined as a function of a vehicle weight, a force transmission capability between tires and road, a road gradient, an operating state of a drive train of the vehicle and / or the availability of other braking systems.

[0025] In general, a vehicle weight, a force transmission capacity between tires and road, a road gradient, an operating state of a vehicle's drive train and / or the availability of other braking systems can also be used to determine other variables by the method.

[0026] A vehicle weight can, for example, include an unladen weight of the vehicle, an actual payload, an actual weight and / or a maximum permissible weight. For example, a weight, such as the actual weight, can be determined by the vehicle itself, for example by determining the spring travel in the compressed state or by corresponding force sensors. Additionally or alternatively, however, a weight can also be taken into account by means of an estimate or assumption of the corresponding weight. For example, this can be the case if a trailer is coupled to a towing vehicle and its weight can only be estimated or assumed, but not determined by measurement. Furthermore, it can be provided that a weight is taken into account by means of an input. For example, a person can enter the known weight of a vehicle load as an input variable for the method.The vehicle weight can also be determined from the additional drive power required to accelerate the vehicle or to move it uphill, particularly compared to operating the vehicle with a reference weight, e.g., the unladen weight. Braking power, particularly regenerative braking power, can also be used to determine the vehicle weight. Braking power is preferably recorded while driving downhill. Alternatively or additionally, the vehicle weight can also be obtained from other vehicle systems, such as a suspension, stabilization, or braking system (e.g., EBS, ABS, ESP).

[0027] The force transmission capacity between tires and the road is primarily characterized by the friction coefficient between the tire and the road. This can be estimated using known methods or assumed to be a constant value.

[0028] The gradient can be taken from digital maps or determined by measurement. It can be taken into account, for example, using a gradient value or a gradient angle. The measurement can be made using, for example, an incline sensor on the vehicle and / or acceleration sensors on the vehicle. It should be noted that on an incline, i.e. when driving uphill, a lower limit value may be permissible because, despite a comparatively low possible deceleration rate, the downhill force supports braking or stopping. In contrast, a higher limit value can be used on a downhill slope for the same possible deceleration rate. In this case, the downhill force would counteract braking or stopping, meaning the vehicle's braking system would also have to compensate for the downhill force.

[0029] An operating state of the drivetrain can, for example, be understood as a gear ratio at which the drivetrain is operated. In conventionally or hybrid-powered vehicles, this can be the gear ratio with which an internal combustion engine brakes the vehicle during overrun. In an electrically powered vehicle, the electric drive motor acting as a generator can brake the vehicle via the gear ratio instead of an internal combustion engine. In a hybrid-powered vehicle, both the internal combustion engine and an electrically powered drive motor can brake via the same gear ratio or different gear ratios. Furthermore, the operating state can include the current storage capacity of an electrical energy storage device.For example, if a braking effect is generated by an electric drive motor in a regenerative manner, the resulting energy can only be stored if the corresponding energy storage device currently has sufficient storage capacity. If this is not possible, the regenerative brake can no longer be used if the resulting energy cannot be consumed in another way. In this case, the limit value must be lowered accordingly.

[0030] Finally, the availability of other braking systems can include damage, wear and tear, but also the availability of a generator brake or a continuous brake as described above.

[0031] Preferably, the method is designed such that the possible deceleration value of a brake is assigned to the at least one brake. This means that a corresponding possible deceleration value can be determined individually for a considered brake, which the brake would generate in response to a corresponding control variable.

[0032] However, a possible deceleration value can also be assigned to several or all brakes of the at least one brake. This can be particularly useful if individual brakes cannot be separately captured by the braking system model, or if no input values for these brakes can be entered into the braking system model. The possible deceleration value can then, in particular, comprise an average value of the corresponding brakes or a maximum or minimum value. It can therefore be provided that such a possible deceleration value is determined from the specification of a possible manipulated variable.

[0033] If the vehicle comprises at least one additional braking system with at least one additional brake whose potential deceleration value is not determined by the braking system model, the potential deceleration value of the at least one additional brake can preferably be determined from an achieved braking effect, such as a vehicle deceleration, during an actual braking application. If the vehicle is braked, the contribution of the brakes to the braking effect can also be determined based on the determined potential deceleration value of the brakes, whose potential deceleration value(s) is / are determined by the braking system model, and / or based on the actual deceleration value of these brakes.The braking effect can be used here as the deceleration actually achieved by the vehicle, which can be detected, for example, using an acceleration sensor and / or by observing the speed before and after braking, in particular the resulting speed difference. From this determined braking effect and the proportion of brakes whose potential deceleration is known or has been determined, the proportion of brakes whose potential deceleration is not determined by the braking system model can also be determined. In this way, with a known manipulated variable, an actual deceleration value can be assigned to the at least one additional brake, which can then be converted, in particular extrapolated, for example, to a deceleration value corresponding to another possible manipulated variable.

[0034] Preferably, the at least one further brake is provided in a further vehicle part that is articulated to a first vehicle part. The further vehicle part can comprise a trailer that is coupled to the first vehicle part. The first vehicle part can comprise a towing vehicle and / or a further trailer. However, it can also be provided that both vehicle parts form an articulated vehicle that is not coupled to the trailer and towing vehicle in accordance with the design. This includes, for example, buses whose front section (first vehicle part) and rear section (further vehicle part) are articulated to one another.

[0035] Preferably, a force measurement, in particular a coupling force measurement, is carried out between the first and the further vehicle part. This can be carried out, for example, by means of a detection means, in particular by means of a force sensor, in the coupling point, which records pushing and pulling forces between the two vehicle parts. The information from the force measurement can then be used to determine the actual deceleration level of the further brake. If the further vehicle part is arranged behind the first vehicle part in the direction of travel and if, for example, a pushing force is measured at the coupling point during braking, the further vehicle part pushes the first vehicle part. If this pushing force is higher than, for example, a predetermined limit value orIf this thrust does not correspond to the expected behavior, it can be concluded that the other brake is not achieving the deceleration value that actually corresponds to the actually set control value. If a tractive force is measured at the coupling point during braking, the other part of the vehicle decelerates more strongly than the first part of the vehicle. If it can be concluded from the previous considerations that the brakes for which a possible deceleration value is being determined are intact, this suggests that at least one other brake is generating too high a deceleration value. However, this information can also be used to conclude that the brakes for which the possible deceleration value is being determined are in poor condition, meaning that they are not achieving this deceleration value.

[0036] The at least one further brake is preferably provided on a trailer and / or a lifting axle of the vehicle.

[0037] In general, a brake force distribution can also be considered when implementing the method. For example, if it is known that certain brakes, e.g., the brakes at the front of the vehicle, experience a higher actuating variable, their load can be taken into account by the braking system model. If this is not possible, an indirect load can be determined by knowing the vehicle deceleration or braking effect and the known deceleration variables.

[0038] The braking system model is preferably updated based on a history of braking interventions. In order to improve the accuracy of the braking system model, it can be provided that braking interventions that have already been carried out, i.e. values for actually set manipulated variables and the resulting braking effect, are used to update the braking system model. In particular, these are comparatively more recent braking interventions in order to base the update on the current state of the at least one brake as much as possible. However, it can additionally or alternatively be provided, in particular when the braking system model is used to determine the maximum possible deceleration amount, that only braking actions with a certain minimum manipulated variable amount are taken into account. It is preferably provided that the braking system model is updated periodically or permanently.Alternatively or additionally, an unscheduled update is provided. This can be forced, for example, by the driver or triggered by changes to the vehicle, such as a change in the load or vehicle configuration, for example, by replacing, connecting, or disconnecting a vehicle part.

[0039] The brake system model preferably has a characteristic map and / or a physical model of the at least one brake. In particular, it can be provided that the brake system model operates with a proportionality factor or a brake characteristic value that allows a proportional conversion of the manipulated variable into a deceleration variable. The proportionality factor can be defined as a constant value, stored in a characteristic map, or calculated using a physical model. The proportionality factor can be configured, in particular, depending on the following input variables, as described above: - Temperature, especially of the brake, - travel and / or - Operating angle.

[0040] This results in a calculation of the possible control variable according to the following relationship: Possible delay value = proportionality factor * possible manipulated variable

[0041] The proportionality factor can include additional parameters, such as a transmission ratio or an efficiency between the manipulated variable and the deceleration variable. In the specific case of a disc brake, an average friction radius can also be taken into account or already included in the transmission ratio.

[0042] According to a further aspect of the invention, a device for carrying out the method described above is provided, comprising - an interface for receiving input variables; - an interface for outputting the possible deceleration value of at least one brake; and - a data processing unit designed to carry out the method described above.

[0043] Such a device can, for example, be designed as a brake control unit or provide part of the functionality of a brake control unit. However, the device can also be a higher-level, independent functional unit for brake monitoring, or one integrated into another device.

[0044] The data processing unit preferably comprises electronic means for data processing.

[0045] According to a further aspect of the invention, a vehicle is provided for carrying out the method described above, wherein the vehicle is designed to carry out the method described above and / or has a device described above, wherein the vehicle is preferably designed as a commercial vehicle, truck, trailer, bus and / or as a combination of towing vehicle and trailer, and / or wherein the vehicle is preferably designed as a purely electric, hybrid or conventionally powered vehicle.

[0046] According to a further aspect of the invention, a computer program product is provided with program code configured such that, when executed on a data processing unit, in particular a data processing unit as mentioned above, it causes the data processing unit to execute the method described above. Thus, it is advantageously possible to appropriately enable existing devices and / or vehicles with data processing units so that they can then execute the method described above.

[0047] According to a further aspect of the invention, a storage medium with a computer program product described above is provided. This makes it possible to easily distribute the computer program product, for example, to enable devices with data processing units or vehicles accordingly. A corresponding storage medium includes, for example, a CD-ROM, a memory stick, a memory card, or even a cloud storage from which the computer program product can be downloaded.

[0048] All features used above in the description of the method can be applied analogously to the other items: device, vehicle, computer program product, and storage medium. If a feature of these items was directly mentioned in the description of the method, this is to be understood as an optional feature of the corresponding item.

[0049] The invention is explained in more detail below using a specific embodiment with the aid of the attached drawings.

[0050] It shows Fig. 1 a basic structure of a brake and its actuation, Fig. 2 parameters influencing the braking process, and Fig. 3 shows a schematic plan view of a vehicle.

[0051] Fig. 1 shows the basic structure of a brake and its actuation.

[0052] The exact representation of all components has been omitted here. The drawing in Fig. 1 merely shows a functional principle.

[0053] The brake 1 is designed here as a friction brake, comprising brake pads 2 and a brake disc 3 rotatable about an axis A. The brake pads are arranged in a brake caliper 4, which surrounds the brake disc 3 on both sides. The brake pads 2 and the brake disc 3 function as friction elements that can be brought into frictional contact with each other to generate a deceleration factor.

[0054] An actuator 5 is provided for actuating the brake 1. This actuator has an actuating element 6, which can be translated to the left in the drawing.

[0055] Between actuator 5 and brake 1, a transmission mechanism 7 is provided, which has an actuating lever 8 that is pivotable in the plane of the drawing. On the one hand, the transmission mechanism 7 is connected to the actuator 5, so that a displacement of the actuating element 6 is introduced into the transmission mechanism 7, causing the actuating lever 8 to pivot counterclockwise. On the other hand, the transmission mechanism 7 is in contact with the brake 1 in order to introduce a displacement or force resulting from the displacement of the actuating element 6 into the brake 1, in order to contact the brake pads 2 with the brake disc 3, thus generating the deceleration value of the brake 1.

[0056] In the case of a disc brake, the deceleration variable can be a braking torque resulting from an application force, i.e. a force with which the brake pads 2 are pressed against the brake disc 3, and an average friction radius.

[0057] The transmission mechanism 7 provides a transmission ratio that describes the transmission of an actuator force or the resulting displacement of the actuating element 6 into the clamping force.

[0058] To determine a deceleration variable that can be generated by brake 1 in response to a manipulated variable, a brake system model can be provided that takes these conditions into account. In certain embodiments, a proportionality factor is provided that maps the conversion of the manipulated variable into the deceleration variable. If an efficiency is known, for example, of the entire arrangement shown or of parts thereof, a possible braking force can be calculated by entering a possible manipulated variable into the brake system model: MB=c*×i×FZ×η×Rm M B Delay size c* Proportionality factor i Gear ratio F z Actuator force η efficiency R m average friction radius

[0059] The actuator 5 is kept general here. In some embodiments, the actuator 5 is designed as a fluidically actuated, in particular as a pneumatically or hydraulically actuated, actuator. According to other embodiments, the actuator 5 is electrically actuated, i.e. a brake 1 actuated in this way is classified as an electromechanical braking system. With fluidic actuation, the actuator 5 can have a cylinder with a piston in order to displace the actuating element 6 by means of pressure. With electrical actuation, the actuator 5 can have a linear motor or a rotary electric motor, wherein the rotary movement thereof is then preferably converted into a translatory movement by means of a corresponding mechanism in order to displace the actuating element 6.

[0060] According to other embodiments, the transmission mechanism 7 can be omitted. It is therefore also possible for the actuator 5 or its actuating element 6 to act directly, i.e., without transmission, on the brake 1, causing the friction elements 2, 3 to press against each other.

[0061] Finally, brake 1 can also be based on a different technical or physical principle. For example, a drum brake or a friction brake that contacts a friction element that is stationary relative to the vehicle, such as a magnetic track brake, is conceivable.

[0062] Fig. Figure 2 shows a basic diagram of parameters influencing the braking process of a vehicle.

[0063] A vehicle 10 is shown traveling on a downhill stretch with an incline angle 12. This can be determined, for example, by inclination measurement or digital maps. In addition to an incline angle 12, other suitable variables can also be used, such as a gradient value.

[0064] The vehicle 10 has a drive train 11 and brakes 1. The brakes 1 can be adjusted according to the brakes on Fig. 1. The drive train 11, which is shown only schematically here, can be a conventional, hybrid, or electric drive train. For example, the drive train 11 influences braking by means of electrical energy storage devices that can no longer absorb energy, so that further braking by generator is no longer possible.

[0065] Furthermore, a slope force 13 is shown. This depends on the gradient angle 12 and the weight of the vehicle, which can be defined or determined as described above.

[0066] Vehicle deceleration 14 is directed against the downhill direction of travel. This can be determined based on knowledge of the potential deceleration magnitude, such as a potential braking torque of brake 1(s) 1, and vehicle parameters such as vehicle weight. If this is too low compared to a limit value specified, for example, by law, appropriate countermeasures must be taken, such as a warning, maintenance, or even stopping the vehicle.

[0067] Fig. 3 shows a schematic plan view of a vehicle.

[0068] The vehicle 10 comprises a towing vehicle 20 and a trailer 21, which are connected to one another at a coupling point 22 so that the trailer 21 can be pulled by the towing vehicle 20 in the direction of travel 19. The towing vehicle 20 and the trailer 21 each have at least one brake (not shown). The towing vehicle 20 forms a first vehicle part, which is articulated to another vehicle part, the trailer 21. The vehicle parts shown here are detachably connected to one another. However, it is also conceivable for this connection to be non-detachable, i.e. for the two vehicle parts not to function as towing vehicle 20 and trailer 21, but rather to form, for example, an articulated vehicle, such as an articulated bus.

[0069] The coupling point 22 is designed to determine a coupling force 23 between the vehicle parts, for example, using a coupling force detection means, in particular a coupling force sensor. In particular, a statement about the braking effect of the vehicle parts can be made here.

[0070] If it is determined that the coupling force 23 during a braking operation indicates a pushing of the rear part of the vehicle, in this case the trailer 21, then, by comparing both vehicle parts, it can be concluded that the front part of the vehicle is braking more strongly or has a stronger braking effect. If, however, it is determined that a pulling force is exerted at the coupling point 22, this indicates a stronger braking or a stronger braking effect of the rear part of the vehicle.

[0071] If, for example, the deceleration value of the at least one brake can only be determined in one part of the vehicle, i.e. only in the towing vehicle 20 or in the trailer 21, the deceleration value of the at least one brake of the vehicle part can be deduced from the coupling force 23, which cannot be captured by the brake system model, by determining the actual braking effect during braking as described above and inferring the deceleration value of the at least one brake of this vehicle part from the coupling force 23 with a known manipulated variable or known manipulated variable amount. LIST OF REFERENCE SYMBOLS 1 brake 2 brake pads 3 brake disc 4 brake caliper 5 Actuator 6 Actuating element 7 Translation mechanism 8 operating levers 9 operating angles 10 vehicles 11 Powertrain 12 pitch angles 13 Downhill force 14 Vehicle deceleration 19 Direction of travel 20 towing vehicle 21 followers 22 coupling point 23 Coupling force A axis

Claims

[1] Method for determining a possible deceleration value of a braking system of a vehicle (10), wherein the braking system comprises at least one brake (1), the method comprising the following steps: - Providing a possible manipulated variable amount that corresponds to an actual manipulated variable amount that can be set by the braking system, wherein the at least one brake (1) is designed to generate a deceleration variable in response to a manipulated variable of this actual manipulated variable amount; - Providing a brake system model which is designed to determine a deceleration value of the at least one brake (1) from an input manipulated variable amount; - Entering the possible manipulated variable amount into the braking system model; - Determining a possible deceleration value of the at least one brake (1) corresponding to the possible manipulated variable amount by means of the brake system model. [2] The method of claim 1, wherein the possible manipulated variable amount comprises a maximum possible manipulated variable amount. [3] Method according to one of the preceding claims, wherein the possible manipulated variable amount comprises an amount of a contact pressure force, a clamping force, an actuator force, an actuator pressure, an actuator current and / or an actuator voltage. [4] Method according to one of the preceding claims, wherein the at least one brake (1) of the braking system comprises a friction brake. [5] Method according to one of the preceding claims, wherein the brake system model comprises as a further input variable a temperature, in particular of the at least one brake (1), a travel and / or an actuation angle (9). [6] Method according to one of the preceding claims comprising at least one of the following steps: - Comparison of the determined possible delay value with a limit value; - Determining a possible vehicle deceleration (14) from the determined possible deceleration value, wherein the limit value and / or the possible vehicle deceleration (14) is preferably determined as a function of a vehicle weight, a force transmission capacity between tires and road, a road gradient (12), an operating state of a drive train (11) of the vehicle (10) and / or the availability of other braking systems. [7] Method according to one of the preceding claims, wherein the possible deceleration value is assigned to one brake, several brakes or all brakes of the at least one brake (1). [8] Method according to one of the preceding claims, wherein the vehicle comprises at least one further braking system with at least one further brake, the possible deceleration value of which is not determined by the braking system model, wherein the possible deceleration value of the at least one further brake is determined from a braking effect achieved during an actually carried out braking operation. [9] Method according to claim 8, wherein the at least one further brake is provided in a further vehicle part which is articulated to a first vehicle part, wherein preferably a force measurement is carried out between the first and the other vehicle part. [10] Method according to one of the preceding claims, wherein the braking system model is updated based on a history of braking interventions. [11] Method according to one of the preceding claims, wherein the brake system model comprises a characteristic map and / or a physical model of the at least one brake. [12] Device for carrying out the method according to one of the preceding claims, comprising - an interface for receiving input variables; - an interface for outputting the possible deceleration value of at least one brake; and - a data processing unit designed to carry out the method according to one of claims 1 to 11. [13] Vehicle (10) for carrying out the method according to one of claims 1 to 11, wherein the vehicle (10) is designed to carry out the method according to one of claims 1 to 11 and / or has a device according to claim 12, wherein the vehicle (10) is preferably designed as a commercial vehicle, truck, trailer, bus and / or as a combination of towing vehicle and trailer, and / or wherein the vehicle (10) is preferably designed as a purely electric, hybrid or conventionally powered vehicle. [14] Computer program product with program code which is configured such that when executed on a data processing unit, in particular a data processing unit according to claim 12, it causes the latter to execute the method according to one of claims 1 to 11. [15] A storage medium comprising a computer program product according to claim 14.

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