determining achievable deceleration variable

Abstract

The invention relates to a method for determining an achievable deceleration variable of a brake system of a vehicle (10), the brake system comprising at least one brake (1), the method having the steps of: providing an achievable adjustment variable value corresponding to an actual adjustment variable value which can be provided by the brake system, the at least one brake (1) being configured to generate a deceleration variable in response to an adjustment variable of the actual adjustment variable value; providing a brake system model, the brake system model being configured to determine the deceleration variable of the at least one brake (1) from an input adjustment variable value; inputting the achievable adjustment variable value into the brake system model; determining, by means of the brake system model, an achievable deceleration variable of the at least one brake (1) corresponding to the achievable adjustment variable value. The invention also relates to a device for carrying out the method, a vehicle, a computer program product and a storage medium.

Description

Technical Field

[0001] The present invention relates to a method for determining achievable deceleration variables, and an apparatus, vehicle, computer program product, and storage medium for performing the method. Background Technology

[0002] Due to the development of electric vehicles and the related feasibility of achieving vehicle braking through generator-like operation of electric drive machines, there are methods to eliminate the need for traditional continuous braking devices, such as decelerators. Because of the limited storage capacity of corresponding electric energy storage devices and the related limited recovery capabilities and therefore limited braking capacity, laws and regulations have been or are being developed to inform drivers, especially those in the commercial vehicle sector, of their vehicle's braking power capabilities, particularly concerning mechanical brakes. This is to be used at the latest when continuous braking is unavailable, for example, through generator-like operation of the electric drive machine. Specifically, this aims to inform the driver of the vehicle's maximum achievable deceleration. However, unrelatedly, even for other types of road vehicles, such as conventionally driven or hybrid vehicles, there is a need to be able to determine braking power capabilities as accurately as possible in order to react during driving conditions and, on the other hand, to better, and particularly more economically, formulate maintenance measures.

[0003] Modern vehicles offer the feasibility of roughly estimating brake pad wear. Therefore, the total wear of disc brakes, i.e., the sum of the wear on the pads and the disc, can be monitored. This can be achieved either by using a potentiometer that reacts as pad wear progresses accordingly, or by using a continuous potentiometer whose signal also allows for conclusions about wear development before complete wear. Alternatively, a sliding contact can be used, which is triggered when it becomes exposed due to wear.

[0004] It is not possible to achieve a definite achievable deceleration variable, such as braking torque or achievable vehicle deceleration. Summary of the Invention

[0005] Therefore, the object of the present invention is to solve the aforementioned problem.

[0006] To this end, the present invention proposes a method for determining the achievable deceleration variable of a vehicle's braking system, wherein the braking system includes at least one brake, and the method comprises the following steps:

[0007] - Provides an achievable adjustment variable value corresponding to an actual adjustment variable value that can be provided by the braking system, wherein the at least one brake is configured to generate a deceleration variable in response to the adjustment variable of the actual adjustment variable value;

[0008] - Provide a braking system model, the braking system model being constructed such that the deceleration variable of the at least one brake is determined by the input adjustment variable values;

[0009] - Input the achievable adjustment variable values ​​into the braking system model;

[0010] - Determine the achievable deceleration variable of the at least one brake corresponding to the achievable adjustment variable value using the braking system model.

[0011] The vehicle includes at least one additional braking system with at least one additional brake, wherein the achievable deceleration variable of the at least one additional brake is not determined by the braking system model, and the achievable deceleration variable of the at least one additional brake is determined by the braking action achieved during actual braking.

[0012] The present invention also provides an apparatus for performing the method according to the present invention, comprising:

[0013] - An interface for receiving input variables;

[0014] - An interface for outputting the achievable deceleration variables of the at least one brake; and

[0015] - A data processing unit configured to perform the method according to the present invention.

[0016] The present invention also proposes a vehicle for performing the method according to the invention, wherein the vehicle is configured to perform the method according to the invention and / or has the means according to the invention, the vehicle is configured as a commercial vehicle, truck, trailer, bus and / or configured as a combination of tractor and trailer, and / or the vehicle is configured as a pure electric drive, hybrid drive or conventional drive vehicle.

[0017] The present invention also proposes a computer program product having program code configured to cause the data processing unit to perform the method according to the present invention when the program code is executed on the data processing unit.

[0018] The present invention also proposes a storage medium having a computer program product according to the present invention.

[0019] Within the scope of this application, a realizable variable, such as a realizable adjustment variable, a realizable deceleration variable, or a realizable vehicle deceleration, refers to a variable whose value can be just achieved by the system under consideration, the actuator under consideration, etc. That is, it refers to the currently available range of values ​​or, more specifically, the values ​​that can be assumed for the corresponding variable as determined by it.

[0020] Within the scope of this application, a trailer should refer to any possible form of trailer. In particular, a trailer can include a semi-trailer or a full trailer. A tractor unit can be a vehicle capable of towing a trailer by its own power. However, it can also be a vehicle that is towed by itself while simultaneously towing another trailer. In particular, it can be a trolley or trailer configured to be coupled to another trailer.

[0021] According to the present invention, a method is provided for determining an achievable deceleration variable of a vehicle's braking system, wherein the braking system includes at least one brake, the method comprising the following steps:

[0022] - Provides an achievable adjustment variable value corresponding to an actual adjustment variable value that can be provided by the braking system, wherein the at least one brake is configured to generate a deceleration variable in response to the adjustment variable of the actual adjustment variable value;

[0023] - Provide a braking system model, the braking system model being constructed such that the deceleration variable of the at least one brake is determined by the input adjustment variable values;

[0024] - Input the achievable adjustment variable values ​​into the braking system model; and

[0025] - The achievable deceleration variable of the at least one brake, corresponding to the achievable adjustment variable value, is determined by the braking system model.

[0026] Therefore, the determination of the deceleration variable achievable through the determined adjustment variable is performed. For this purpose, a braking system model is used, which maps the characteristics of at least one brake of the vehicle to actual adjustment variables with corresponding adjustment variable values.

[0027] Preferably, the deceleration variable is the braking torque or braking force generated by at least one brake in response to the adjustment variable.

[0028] Preferably, the achievable adjustment variable values ​​include the maximum achievable adjustment variable values. This has the advantage that the maximum achievable deceleration variable can therefore be determined. That is, it is possible to specify the remaining or current strength or power capability of the corresponding brake at each moment.

[0029] Therefore, the achievable deceleration variable is determined by considering the adjustable variables that can be adjusted during operation. That is, if the braking system is technically limited during operation, for example due to a malfunction in the actuator used to operate the brake, a lower achievable deceleration variable can be considered due to the limited adjustable variables. Furthermore, the braking system model can be used to consider which deceleration variables can be set by the achievable adjustable variables, i.e., which deceleration variable can be achieved. If the braking system model is used to consider the deterioration or general changes in the brake state, the achievable, attainable deceleration variable can therefore be determined using this method.

[0030] The braking system model is preferably constructed to consider the state of the brakes by taking into account input variables from the vehicle. Therefore, adjustment variables or their values ​​can be mapped to corresponding deceleration variables, based on the state of at least one brake. For example, if the temperature of the at least one brake is determined by the vehicle, either through measurement or by using a model, the braking system model can account for changes in physical characteristics, particularly changes in the mapping from adjustment variables to deceleration variables. In this way, the achievable deceleration variables, and especially the maximum deceleration variables, can be determined through the braking system model.

[0031] Additional input variables can be provided by inputting the wear variable of the at least one brake. As will be further described below, this could be the adjustment path and / or the steering angle, and in particular, consideration can be given to when these variables reach their maximum values, indicating increased wear.

[0032] Preferably, the achievable adjustable variable values ​​include clamping force, braking force, actuator force, actuator pressure, actuator current, and / or actuator voltage. Clamping force typically describes the strength of the friction element pressing against its corresponding counterpart. Braking force describes the intensity of the braking force applied by the brake element of the brake caliper to the brake disc. Actuator force describes the force of the actuator configured to introduce that force into the braking system. Such actuators are preferably fluidly actuated, i.e., particularly pneumatically, hydraulically, or electromechanically actuated. Therefore, actuator pressure, i.e., fluid pressure, or actuator current or actuator voltage, can also be considered as adjustable variables. The braking system or at least one brake preferably includes a fluidly, particularly pneumatically, or hydraulically, and / or electromechanically actuated brake.

[0033] Preferably, at least one brake in the braking system comprises a friction brake. The friction brake may in particular be a drum or disc brake. The achievable deceleration variable of the brake is determined, and the achievable braking torque generated by the brake is described.

[0034] Preferably, the braking system model includes temperature (especially the temperature of the brake), adjustment path, and / or operating angle as additional input variables. Therefore, the achievable deceleration variable can be determined by the braking system model based on temperature, particularly the temperature of the brake's friction elements such as brake pads and / or brake discs. The determination of the achievable deceleration variable and / or the description of brake wear can also be improved by considering the adjustment path and / or operating angle. A worn brake is operated by a mechanism of translation and / or rotation, particularly a transmission mechanism and / or actuator. If wear increases, this will result in a larger adjustment path and / or operating angle. These can be detected, thus allowing for a description of wear. If the mechanism or actuator has a readjustment device constructed to at least partially balance the effect of wear on the adjustment path and / or operating angle, it is also conceivable to determine wear by detecting the value of such readjustment, i.e., particularly by the readjustment value of the adjustment path and / or operating angle. Considering the adjustment path and / or operating angle may also include considering when wear has progressed to the point where the contact stop and / or the adjustment path and / or operating angle exhibit maximum permissible values.

[0035] Preferably, the method includes the step of comparing a determined achievable deceleration variable with a limit value. For example, the limit value can be configured to be constant or variable. If it is determined that the achievable deceleration variable has not reached the limit value, it is necessarily concluded that the state of the at least one brake, particularly its wear state, is no longer optimal. Maintenance of the brake can then be provided, for example. If a maximum deceleration variable is determined by the maximum achievable adjustment variable, and this maximum deceleration variable has not reached the corresponding limit value, this indicates a safety-critical issue, which may also require countermeasures during driving. For example, the vehicle may be forced to stop.

[0036] Alternatively or additionally, the method includes the steps of determining an achievable vehicle deceleration from the determined achievable deceleration variables. Furthermore, this achievable vehicle deceleration can be compared with a corresponding limit value. This can, for example, be configured to be constant or variable. The above considerations also apply similarly here. If, in particular, it is determined that the maximum achievable vehicle deceleration is below the limit value, a safety-critical issue exists, which may also require countermeasures during driving. For example, the vehicle could be forced to stop.

[0037] Warnings can also be issued to the driver based on the analysis and processing results of achievable deceleration variables and / or achievable vehicle deceleration.

[0038] Preferably, the limit value and / or achievable vehicle deceleration are determined based on the vehicle weight, the force transmission capability between the tires and the road, the road gradient, the operating state of the vehicle's powertrain, and / or the availability of other braking systems.

[0039] Typically, vehicle weight, force transmission capacity between tires and road, road gradient, operating status of the vehicle's powertrain, and / or availability of other braking systems can also be used to determine other variables using this method.

[0040] Vehicle weight can include, for example, the vehicle's net weight, actual payload, actual weight, and / or maximum permissible weight. For instance, weight, such as actual weight, can be determined by the vehicle itself, for example, by determining the spring travel under compression or by a corresponding force sensor. However, additionally or alternatively, weight can also be considered by estimation or assumption of the corresponding weight. This may occur, for example, when a trailer is attached to a tractor and its weight can only be estimated or assumed and cannot be determined by measurement. Furthermore, it can be specified that weight is considered by input. For example, a person can input the known weight of the vehicle's payload as an input variable for this method. Vehicle weight can also be determined based on the additional drive power required to accelerate the vehicle or move on a slope, particularly compared to a vehicle operating with a reference weight (e.g., net weight). Braking power, particularly generator-type braking power, can also be used to infer vehicle weight. Here, it is preferable to detect braking power while traveling on a descent route. Alternatively or additionally, vehicle weight can also be obtained from other vehicle systems, such as suspension, stability, or braking systems (e.g., EBS, ABS, ESP).

[0041] The ability to transmit force between a tire and the road is primarily characterized by the coefficient of friction between them. This can be estimated using known methods or assumed to be a constant value.

[0042] The slope of a route can be obtained, for example, from digital map materials or determined by measurement. For instance, it can be considered using slope values ​​or slope angles. For example, vehicle tilt detection and / or vehicle acceleration sensors can be used for measurement. It is worth considering that in the case of a slope, i.e., uphill driving, a lower limit value may be permissible because the downhill force supports the braking or stopping process, even though the achievable deceleration variable has been determined to be relatively low. In contrast, a higher limit value can be used when descending, given the same determined achievable deceleration variable. In this case, the downhill force counteracts the braking or stopping process, therefore the vehicle's braking system must also balance the downhill force.

[0043] The operating state of a powertrain can refer, for example, to the gear ratio at which the powertrain operates. In the case of conventional or hybrid vehicles, this could be the gear ratio at which the internal combustion engine brakes the vehicle during schubbetrieb (inertial motion). In electric vehicles, the electric drive unit, acting as a generator instead of the internal combustion engine, can brake the vehicle using this gear ratio. In hybrid vehicles, both the internal combustion engine and the electric drive unit can brake using the same or different gear ratios. Furthermore, the operating state can include the current storage capacity of an energy storage device. If braking is generated, for example, by a generator-like operation of the electric drive unit, the generated energy can only be stored in the energy storage device if its current storage capacity is sufficient. If this is not possible, generator-like braking can no longer be used when the generated energy cannot be used in other ways. In this case, the limit value must be reduced accordingly.

[0044] Finally, the availability of other braking systems can refer to damage or wear, but it can also refer to the aforementioned availability of generator brakes or continuous brakes.

[0045] Preferably, the method is designed such that an achievable deceleration variable is assigned to one of the at least one brakes. That is, the corresponding achievable deceleration variable generated by the brake in response to a corresponding adjustment variable can be determined individually for each brake under consideration.

[0046] However, the achievable deceleration variable can also be assigned to multiple brakes or all brakes in the at least one brake. This is particularly meaningful when a single brake cannot be detected by the braking system model alone, or when input variables cannot be fed into the braking system model for these brakes. The achievable deceleration variable can then, in particular, include the average, maximum, or minimum value of the corresponding brake. Thus, it can be specified that such an achievable deceleration variable is determined from predetermined values ​​of the achievable adjustment variable.

[0047] If the vehicle includes at least one additional braking system with at least one additional brake, and the achievable deceleration variable of this additional brake is not determined by the braking system model, then the achievable deceleration variable of this additional brake can preferably be determined by the braking action achieved during actual braking, such as vehicle deceleration. If the vehicle is braked, the achievable deceleration variable of the brake is determined by the braking system model based on the determined achievable deceleration variable of the brake, and / or the proportion of the braking action of the brake is also determined based on the actual deceleration variable of the brake. The actual deceleration of the vehicle can here be used as the braking action, which can be detected, for example, by an acceleration sensor and / or by considering the speed before and after braking, particularly the resulting speed difference. The proportion of brakes whose achievable deceleration variables are known or determined based on the braking action thus determined and their achievable deceleration variables can also be determined for the proportion of brakes whose achievable deceleration variables are not determined by the braking system model. In this way, if the adjustment variable is known, an actual deceleration variable can be assigned to at least one additional brake, which can then be, for example, converted, particularly extrapolated, to a deceleration variable corresponding to another achievable adjustment variable.

[0048] Preferably, the at least one additional brake is disposed in a separate vehicle section articulated to the first vehicle section. This separate vehicle section may include a trailer connected to the first vehicle section. The first vehicle section may include a tractor and / or a separate trailer. However, it may also be specified that the two vehicle sections form an articulated vehicle, which, depending on the construction, is not connected to a trailer or tractor. This includes, for example, a bus whose front section (the first vehicle section) and rear section (the other vehicle section) are articulated to each other.

[0049] Preferably, force measurements, particularly coupling force measurements, are performed between the first vehicle section and the other vehicle section. This can be done, for example, by a detection device, particularly by a force sensor at the coupling point, which detects the thrust and pull forces between the two vehicle sections. The information from the force measurements can then be used to infer the actual deceleration variable of the other brake. If the other vehicle section is positioned behind the first vehicle section in the direction of travel and, for example, if thrust is measured at the coupling point during braking, the other vehicle section is pushing the first vehicle section. For example, if the thrust exceeds a predetermined limit, or if the thrust does not correspond to the expected behavior, it can be inferred that the other brake has not achieved the deceleration variable that actually corresponds to the actual set adjustment variable. If pull is measured at the coupling point during braking, the other vehicle section decelerates more than the first vehicle section. If the brake that has determined the achievable deceleration variable from the previous considerations is intact, then this indicates that at least one other brake is producing an excessively high deceleration variable. However, this information can also be used to infer that the brake that has determined the achievable deceleration metric is in poor condition and therefore cannot achieve that deceleration variable.

[0050] At least one additional brake is preferably located on the lifting axle of the trailer and / or vehicle.

[0051] Typically, braking force distribution can also be considered when implementing this method. For example, if a particular brake (e.g., the brakes at the front of the vehicle) is known to be affected by a variable with a higher moderating variable value, the load on that moderating variable can be considered by the braking system model, and / or if this is not feasible, the indirect load can be determined by understanding the vehicle deceleration or braking action and the known deceleration variable.

[0052] Preferably, the braking system model is updated based on the history of braking interventions. To improve the accuracy of the braking system model, it can be specified that the braking interventions that have been performed, i.e., the values ​​of the actual adjusted variables and the braking effects produced therefrom, are used to update the braking system model. In particular, these are relatively recent braking interventions, so that the update is based as much as possible on the current state of at least one brake. However, it can be additionally or alternatively specified that, particularly if the braking system model is used to determine the maximum achievable deceleration variable, only braking processes with a defined minimum adjusted variable value are considered. Preferably, the braking system model is updated periodically or permanently. Alternatively or additionally, it is specified that irregular updates are performed. For example, this can be forced by the driver or triggered by changes to the vehicle, such as changes in load or vehicle configuration, for example, by replacing, connecting, or disconnecting vehicle parts.

[0053] Preferably, the braking system model has characteristic curves and / or a physical model of the at least one brake. Specifically, it can be specified that the braking system model works in conjunction with a scaling factor or braking characteristic value, which allows the adjustment variable to be scaled into a deceleration variable. The scaling factor can be set to a constant value, stored in the characteristic curve, or calculated using the physical model. The scaling factor can be designed, in particular, based on the following input variables (as described above):

[0054] - Temperature, especially the temperature of the brakes,

[0055] - Adjust path and / or

[0056] - Adjust the angle.

[0057] Therefore, it is preferable to result in the calculation of achievable adjustment variables based on the following relationship:

[0058] achievable deceleration variable = scale factor * achievable adjustment variable

[0059] The scaling factor can include other parameters, such as the conversion ratio or efficiency between the regulating and decelerating variables. In the specific case where the brake is constructed as a disc brake, the average friction radius can also be considered or is already included in the conversion ratio.

[0060] According to another aspect of the present invention, an apparatus for performing the above-described method is provided, comprising:

[0061] - An interface for receiving input variables;

[0062] - An interface for outputting the achievable deceleration variables of the at least one brake; and

[0063] - Constructed as a data processing unit for performing the above methods.

[0064] Such a device can be configured as a brake control device, or provide part of the functions of a brake control device. However, it can also be specified that the device constitutes a higher-level, independent, or integrated functional unit in another device for monitoring braking.

[0065] The data processing unit preferably includes electronic devices for data processing.

[0066] According to another aspect of the present invention, a vehicle for performing the above-described method is provided, wherein...

[0067] The vehicle is configured to perform the above-described method and / or has the above-described device.

[0068] The vehicle is preferably configured as a commercial vehicle, truck, trailer, bus, and / or a combination of tractor and trailer, and / or

[0069] The vehicle is preferably configured as a pure electric drive, hybrid drive, or conventional drive vehicle.

[0070] According to another aspect of the invention, a computer program product having program code configured such that when the program code is executed on a data processing unit, particularly the aforementioned data processing unit, the data processing unit is caused to perform the described method. Therefore, it is advantageous to accordingly enable existing devices and / or vehicles having data processing units, so that they can then perform the described method.

[0071] According to another aspect of the invention, a storage medium having the aforementioned computer program product is provided. In this way, the computer program product can be easily transferred to, for example, enable a device or vehicle with a data processing unit. The corresponding storage medium includes, for example, a CD-ROM, a memory stick, a memory card, or a cloud storage device from which the computer program product can be downloaded.

[0072] All the features used in the method description above can be similarly transferred to other subjects: apparatus, vehicles, computer program products, and storage media. If features of these subjects are directly mentioned in the method description, they should be understood as optional features of the corresponding subjects. Attached Figure Description

[0073] The invention will now be explained in more detail with reference to the accompanying drawings and specific embodiments.

[0074] In the attached diagram:

[0075] Figure 1 The basic structure of the brake and its actuation are shown.

[0076] Figure 2 The parameters affecting the braking process are shown, and

[0077] Figure 3 A schematic top view of the vehicle is shown. Detailed Implementation

[0078] Figure 1 The basic structure of the brake and its actuation are shown.

[0079] The exact representation of all components is omitted here. Figure 1 The diagram in the image only illustrates the functional principle.

[0080] Brake 1 is configured here as a friction brake, having brake pads 2 and a brake disc 3 rotatable about axis A. The brake pads are disposed in brake calipers 4, which surround the brake disc 3 on both sides. The brake pads 2 and brake disc 3 function as friction elements, capable of rubbing against each other to produce deceleration.

[0081] Actuator 5 is provided for actuating brake 1. It has an actuating element 6 that can be translated to the left in the figure.

[0082] A transmission mechanism 7 is disposed between the actuator 5 and the brake 1. This transmission mechanism has a lever 8 configured to pivot in the plane of the drawing. On one hand, the transmission mechanism 7 is connected to the actuator 5, thereby inducing movement of the actuating element 6 into the transmission mechanism 7, whereby the lever 8 pivots counterclockwise. On the other hand, the transmission mechanism 7 contacts the brake 1 to introduce movement, or the force generated by the movement of the actuating element 6, into the brake 1, thereby causing the brake pads 2 to contact the brake disc 3, thus generating a deceleration variable in the brake 1.

[0083] In the case of disc brakes, the deceleration variable can be the braking torque generated by the applied braking force (i.e., the force of the brake pads 2 pressing against the brake disc 3) and the average friction radius.

[0084] The transmission ratio is given by the transmission mechanism 7, which describes the transmission ratio of the actuator force or the actuator element 6 generated therefrom to the braking force.

[0085] To determine the deceleration variable that can be generated by brake 1 in response to the adjustment variable, a braking system model considering these cases can be provided. Here, in the determined embodiment, a scaling factor is provided, which maps the transformation of the adjustment variable to the deceleration variable. If the efficiency, such as the efficiency of the entire arrangement or a portion thereof as shown, is known, the achievable braking force can be calculated by inputting the achievable adjustment variable into the braking system model.

[0086]

[0087] M B Deceleration variable

[0088] c*: Scale factor

[0089] i: Transmission ratio

[0090] F z Actuator force

[0091] η: Efficiency

[0092] R m Average friction radius

[0093] Actuator 5 remains generic here. In some embodiments, actuator 5 is configured as a fluid-operated, particularly pneumatic or hydraulic, actuator. According to other embodiments, actuator 5 is electrically operated, i.e., the brake 1 operated in this way can be classified as an electromechanical braking system. In the case of fluid operation, actuator 5 may have a cylinder with a piston to move the actuating element 6 by pressure. In the case of electrical operation, actuator 5 may have a linear motor or a rotary electric motor, wherein preferably its rotational motion is converted into translational motion by a corresponding mechanism to move the actuating element 6.

[0094] In other embodiments, the transmission mechanism 7 may be omitted. Therefore, the actuator 5, or its operating element 6, may also act directly, i.e. without transmission, on the brake 1 and cause the friction elements 2 and 3 to press against each other there.

[0095] Finally, brake 1 can also be based on other technologies or physical principles. For example, a drum brake or friction brake that contacts a friction element that is stationary relative to the vehicle can be conceived, such as in the case of a magnetic rail brake.

[0096] Figure 2 The parameters affecting the vehicle braking process are illustrated in the schematic diagram.

[0097] Vehicle 10 is shown moving on a descent route with a slope angle of 12. This can be determined, for example, by tilt measurement or digital map material. In addition to the slope angle 12, other suitable variables, such as tilt indicators, can also be used.

[0098] Vehicle 10 has a powertrain 11 and a brake 1. The brake 1 can be adjusted according to... Figure 1 The brake configuration in the diagram. The powertrain 11 shown here is only schematic and can be a conventional, hybrid, or electric powertrain. For example, the powertrain 11 affects braking through a non-absorbable electrical energy storage device, thus preventing generator-type braking.

[0099] Downhill force 13 is also shown. It depends on the slope angle 12, which can be defined or determined as described above, and the vehicle's weight.

[0100] The vehicle deceleration 14 is oriented in the opposite direction to the downhill travel direction. This can be determined if the achievable deceleration variable (i.e., achievable braking torque) of one or more brakes 1 and vehicle parameters (e.g., vehicle weight) are known. If this is too low compared to, for example, legally prescribed limits, appropriate countermeasures must be taken, such as warnings, maintenance, or termination of operation.

[0101] Figure 3 A schematic top view of the vehicle is shown.

[0102] Vehicle 10 includes a tractor unit 20 and a trailer 21, which are connected to each other at a coupling point 22 such that the trailer 21 can be towed by the tractor unit 20 in the direction of travel 19. The tractor unit 20 and the trailer 21 each have at least one brake (not shown). The tractor unit 20 forms a first vehicle section articulated to the other vehicle section, the trailer 21. The vehicle sections shown here are detachably connected to each other. However, it is also conceivable that this connection is not constructed to be detachable, i.e., the two vehicle sections are not used as tractor unit 20 and trailer 21, but rather form, for example, an articulated vehicle, such as an articulated bus.

[0103] The connection point 22 is configured to determine the connection force 23 between the vehicle parts, for example, by means of a connection force detection device, particularly by means of a connection force sensor. Here, the braking action of the vehicle parts can be explained in particular.

[0104] If it is determined that the coupling force 23 during the braking process indicates that the rear vehicle section (in this case, trailer 21) is being pushed, then a comparison of the two vehicle sections can show that the front vehicle section is braking more strongly or has a stronger braking effect. If it is determined that the vehicle is being pulled at the coupling point 22, this can also indicate that the rear vehicle section is braking more strongly or has a stronger braking effect.

[0105] For example, if the deceleration variable of at least one brake can only be determined in one vehicle segment, i.e. only in the tractor 20 or trailer 21, the deceleration variable of at least one brake of that vehicle segment that cannot be detected by the braking system model can be inferred based on the connecting force 23, in order to determine the actual braking action during braking as described above and infer the deceleration variable of at least one brake of that vehicle segment from the connecting force 23 when the adjustment variable or the value of the adjustment variable is known.

[0106] List of reference numerals

[0107] 1 Brake

[0108] 2 Brake pads

[0109] 3 brake discs

[0110] 4 brake calipers

[0111] 5 Actuators

[0112] 6. Control elements

[0113] 7. Transmission Mechanism

[0114] 8 joysticks

[0115] 9. Control angle

[0116] 10 vehicles

[0117] 11 Powertrain

[0118] 12 slope angle

[0119] 13 Downhill Force

[0120] 14 Vehicle deceleration

[0121] 19. Direction of travel

[0122] 20 tractor units

[0123] 21 trailers

[0124] 22 connection points

[0125] 23 Connectivity

[0126] Axis A

Claims

1. A method for determining the achievable deceleration variable of the braking system of a vehicle (10), wherein, The braking system includes at least one brake (1), and the method comprises the following steps: - Provides an achievable adjustment variable value corresponding to the actual adjustment variable value that can be provided by the braking system, wherein the at least one brake (1) is configured to generate a deceleration variable in response to the adjustment variable of the actual adjustment variable value; - Provide a braking system model, the braking system model being constructed to determine the deceleration variable of the at least one brake (1) by the input adjustment variable values; - Input the achievable adjustment variable values ​​into the braking system model; - Determine the achievable deceleration variable of the at least one brake (1) corresponding to the achievable adjustment variable value using the braking system model. The vehicle includes at least one additional braking system with at least one additional brake, wherein the achievable deceleration variable of the at least one additional brake is not determined by the braking system model, and the achievable deceleration variable of the at least one additional brake is determined by the braking action achieved during actual braking.

2. The method according to claim 1, wherein, The achievable values ​​of the moderating variable include the largest achievable values ​​of the moderating variable.

3. The method according to claim 1 or 2, wherein, The achievable adjustable variable values ​​include the clamping force of the friction element pressing against the corresponding component, the braking force applied by the braking element of the brake caliper to the brake disc, the actuator force of the actuator introduced into the braking system, the actuator pressure used to operate the actuator, and the values ​​of actuator current and / or actuator voltage.

4. The method according to claim 1 or 2, wherein, The at least one brake (1) of the braking system includes a friction brake.

5. The method according to claim 1 or 2, wherein, The braking system model includes temperature, adjustment path and / or steering angle (9) as additional input variables.

6. The method according to claim 5, wherein, The temperature is the temperature of the at least one brake (1).

7. The method according to claim 1 or 2, wherein, The method includes at least one of the following steps: - Compare the determined achievable deceleration variables with the limit values; - The achievable vehicle deceleration is determined from the determined achievable deceleration variables (14), where, The limit value and / or the achievable vehicle deceleration (14) are determined based on the vehicle weight, the force transmission capability between the tires and the road, the road slope (12), and / or the operating state of the vehicle's (10) powertrain (11).

8. The method according to claim 1 or 2, wherein, The achievable deceleration variable is assigned to one, multiple, or all of the at least one brake (1).

9. The method according to claim 1 or 2, wherein, The at least one additional brake is disposed in a separate vehicle section, which is hingedly connected to the first vehicle section. Force measurements are performed between the first vehicle section and the other vehicle section.

10. The method according to claim 1 or 2, wherein, The braking system model is updated based on the history of braking interventions.

11. The method according to claim 1 or 2, wherein, The braking system model has the characteristic curves and / or physical model of at least one brake.

12. An apparatus for performing the method according to any one of claims 1 to 11, comprising: - An interface for receiving input variables; - An interface for outputting the achievable deceleration variables of the at least one brake; and - A data processing unit configured to perform the method according to any one of claims 1 to 11.

13. A vehicle (10) for performing the method according to any one of claims 1 to 11, wherein, The vehicle (10) is configured to perform the method according to any one of claims 1 to 11 and / or has the apparatus according to claim 12. The vehicle (10) is configured as a commercial vehicle, truck, trailer, bus and / or as a combination of tractor and trailer, and / or The vehicle (10) is configured as a pure electric drive, hybrid drive, or conventional drive vehicle.

14. A computer program product having program code configured to cause the data processing unit to perform the method according to any one of claims 1 to 11 when the program code is executed on the data processing unit.

15. The computer program product according to claim 14, wherein, The data processing unit is the data processing unit according to claim 12.

16. A storage medium having a computer program product according to claim 14 or 15.

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