Method and device for determining a mass of a vehicle, computer program, and data carrier signal
Patent Information
- Application Number
- EP2023792941
- Authority / Receiving Office
- EP · EP
- Patent Type
- Applications
- Current Assignee / Owner
- Priority Date
- 2022-10-18
- Filing Date
- 2023-10-17
- Publication Date
- 2025-08-27
Smart Images
Figure 1.1
Abstract
Description
[0001] Description
[0002] Method and device for determining a mass of a vehicle as well as computer program and data carrier signal
[0003] The invention relates to a method for determining the mass of a vehicle. Specifically, the vehicle can be configured as a trailer, in particular an electrically powered trailer and / or caravan, or as a motor vehicle, in particular an electrically powered motor vehicle and / or mobile home. In particular, the invention relates to the field of recreational vehicles.
[0004] DE 10 2018 220 841 A1 discloses a method for determining a change in the mass of a vehicle to control a starting process from a stationary vehicle. In this known method, a mass value last determined before the vehicle came to a standstill is used as the initial value. Signals from an acceleration sensor are recorded and evaluated. The signals are based on vertical accelerations occurring in the stationary vehicle. The occurrence of the change in the vehicle's mass is determined based on these signals. The recorded signal curve for determining the occurrence of the change in the vehicle's mass can be evaluated using Fourier analysis.
[0005] In the method known from DE 10 2018 220 841 A1, vertical accelerations are recorded when the vehicle is stationary in order to determine mass changes. The determination of the vehicle's mass serves to ensure that a suitable gear can be selected when starting off. The known method is highly inaccurate. In particular, vertical accelerations of the vehicle measured at a point on the vehicle during loading and unloading depend not only on the mass being added or unloaded, but also on the height of the current total mass, the tire pressures, the location on the vehicle where the mass is added or removed, and the like. The known determination of the mass is therefore highly inaccurate. The object of the invention is to specify a method, a device, a computer program and a data carrier signal that enable improved functionality.
[0006] The object is achieved by a method having the features of independent patent claim 1, a device having the features of patent claim 11, a computer program having the features of patent claim 12, and a data carrier signal having the features of patent claim 13. Advantageous developments of the invention are specified in the subclaims.
[0007] The object is achieved by a method for determining at least one mass of a vehicle, in particular a trailer, further in particular an electrically powered trailer and / or a caravan, and / or a motor vehicle, further in particular an electrically powered motor vehicle and / or a mobile home, wherein a signal is sent to a drive control of a drive, which causes the drive control to carry out a pulsed change in the speed of the vehicle by means of the drive, wherein at least one vibration signal from at least one measuring device is received, which describes a vibration of the vehicle excited by the pulsed change in the speed of the vehicle, and wherein a mass of the vehicle is determined on the basis of the vibration signal.
[0008] The object is further achieved by a device for a vehicle, in particular a trailer, further in particular an electrically driven trailer and / or a caravan, and / or a motor vehicle, further in particular an electrically driven motor vehicle and / or a mobile home, with at least one measuring device, wherein the device is adapted to carry out such a method.
[0009] Furthermore, the object is achieved by a computer program comprising instructions that cause such a device to carry out the method steps of such a method. Furthermore, the object is achieved by a data carrier signal that transmits such a computer program. It is advantageous that the drive of a motor vehicle coupled to a vehicle designed as a trailer is controlled by means of the drive control. As a result, an impulse can be exerted on the vehicle via the motor vehicle in order to enable the mass determination. The vehicle designed as a trailer can be designed without an engine, in particular without an auxiliary engine.
[0010] It is advantageous that at least one measuring device detects, at least indirectly, in particular directly, a component of the coupling force acting in the direction of travel of the vehicle between the motor vehicle and the trailer coupled to the motor vehicle, and that the vibration signal is based on the component of the coupling force acting in the direction of travel of the vehicle. This allows the measurement to be carried out on or in the area of the coupling. This can also be retrofitted if necessary.
[0011] It is advantageous for the measuring device to have at least one load cell that measures the clutch force acting in the direction of travel of the vehicle. This allows for advantageous measurement, which is particularly possible with a measuring device located in the vehicle. This allows the measuring device to be advantageously protected from the environment, particularly weather influences, and against damage and theft. Specifically, the measuring device can be integrated into the vehicle.
[0012] It is advantageous for at least one measuring device to be arranged directly on the vehicle, and for the measuring device to detect at least the component of the temporal change in the vehicle's speed directed in the direction of travel of the vehicle using at least one inertial sensor. The term "arrangement on" the vehicle is to be understood generally and also includes an arrangement within the vehicle or integration into components of the vehicle, for example, an underbody.
[0013] It is advantageous that, based on the signal sent to the drive control unit, the drive control unit controls the drive in such a way that a specific torque pulse is applied to the vehicle. This allows a specific specification to be made, enabling reliable measurement. This can also enable simple and reliable application to different vehicles and / or motor vehicles used as towing vehicles. Furthermore, it can facilitate retrofitting.
[0014] It is advantageous that a damped natural angular frequency of the vehicle is determined based on the vibration signal, and that the mass is determined based on the damped natural angular frequency. This allows for precise mass determination with optimized effort.
[0015] It is advantageous to determine the mass based on a stored characteristic map from the damped natural angular frequency, or to determine the mass based on a stored exponential function from the damped natural angular frequency. This allows for advantageous and precise mass determinations with optimized effort.
[0016] It is advantageous that the signal is sent to the drive control system when the vehicle is stationary or starting from a stationary state. This allows for mass determination at the start of the journey.
[0017] It is advantageous if the determined mass is displayed to the driver and / or if the mass is at least approximately the total mass of the vehicle. This allows the driver to be informed and, if necessary, warned. Furthermore, the driver can identify whether a possible violation of safety regulations or legal provisions has occurred and, if necessary, take appropriate action before participating in public road traffic.
[0018] Further advantages and details of the invention are explained in more detail with reference to the exemplary embodiments illustrated in the schematic figures. Herein:
[0019] Fig. 1 shows a combination comprising a motor vehicle serving as a towing vehicle and a vehicle configured as a trailer, illustrating possible embodiments of the invention in a partial, schematic representation, with a side view being shown; Fig. 2A is a diagram illustrating a signal curve of a measuring device comprising an inertial sensor of a device according to a possible embodiment of the invention, which device is used in the combination shown in Fig. 1, with the signal curve being shown for an additional load of 92 kg;
[0020] Fig. 2B shows the diagram shown in Fig. 2A, wherein the signal curve is shown without the additional load mentioned;
[0021] Fig. 2C is a diagram illustrating a signal sent to a drive control of a drive of the vehicle combination shown in Fig. 1, such a signal being the reason why the signal waveforms shown in Figs. 2A and 2B can then be detected by the measuring device;
[0022] Fig. 3A is a diagram illustrating a signal curve of a measuring device designed as a load cell of a device according to a possible embodiment of the invention, which device is used in the combination shown in Fig. 1, the signal curve being shown for an additional load of 92 kg;
[0023] Fig. 3B shows the diagram shown in Fig. 2A, wherein the signal curve is shown without the additional load mentioned;
[0024] Fig. 3C is a diagram illustrating the natural angular frequencies of the signal waveforms shown in Figs. 3A and 3B, the natural angular frequencies being determined by a fast Fourier transform;
[0025] Fig. 4A is a diagram illustrating a characteristic map stored based on the natural angular frequencies determined for various additional masses, which characteristic map can then be used for mass determination according to a possible embodiment of the invention; Fig. 4B is a diagram illustrating the course of a stored exponential function, which exponential function can be used for mass determination according to another possible embodiment of the invention, wherein the exponential function can be determined by a curve fit to the specific natural angular frequencies shown in Fig. 4A;
[0026] Fig. 5A is a diagram illustrating the determination of an additional mass via a characteristic map shown in Fig. 4A or an exponential function shown in Fig. 4B from a measured natural angular frequency in a measuring process in which the additional mass is arranged at the center of mass;
[0027] Fig. 5B is a diagram illustrating the determination of an additional mass using a characteristic map shown in Fig. 4A or an exponential function shown in Fig. 4B from a measured natural frequency in a further measurement process in which the additional mass is not arranged at the center of mass; and
[0028] Fig. 5C shows the diagram shown in Fig. 5A, where the measurement is carried out for a larger additional mass arranged at the center of mass.
[0029] Fig. 1 shows a vehicle combination 1 with a motor vehicle 2, which serves as a towing vehicle 2, and a vehicle 3 designed as a trailer 3 to explain possible exemplary embodiments of the invention in an excerpted, schematic representation. A view from the side is shown. The vehicle 3, which in this exemplary embodiment is designed as a trailer 3, can be an electrically powered trailer 3, so that a range extension is possible, in particular in the case of a battery-electric motor vehicle 2. The trailer 3 can then specifically serve as a caravan. The vehicle 2, which in this exemplary embodiment is designed as a motor vehicle 2, can be an electrically powered motor vehicle 2, whereby the design is not restricted to battery-electric motor vehicles 2. In particular, the motor vehicle 2 can be designed as a mobile home 2.In particular, if the motor vehicle 2 is designed as a mobile home 2, then the invention can also be implemented in a possible embodiment only on the motor vehicle 2, so that the application is not limited to trailers 1 and is also possible for individual vehicles 2.
[0030] Using the trailer 1 shown in Fig. 1, possible embodiments of a method for determining at least one mass of the vehicle 3 are described. To simplify the illustration, a determination of a mass m of the vehicle 3 and an additional mass (payload) m is described. In a modified embodiment, however, at least one mass of the vehicle 2 can also be determined, for which the trailer 3 can be coupled or uncoupled.
[0031] A possible embodiment of the invention is described with reference to Figs. 2A to 2C. The signal S or pulse waveform I is plotted against time t in these and Figs. 3A and 3B. A signal I (Fig. 2C) is sent to a drive control 4 of the drive 6 of the motor vehicle 2. The signal I causes the drive control 4 of the drive 6 to execute a pulsed change in the speed of the vehicle 2. As a result, a vibration signal S (Figs. 2A and 2B) can be received by the measuring device 9, which describes a vibration 10 of the vehicle 3 excited by the pulsed change in speed of the vehicle 2.
[0032] In this exemplary embodiment, a starting impulse, for example, is initially generated via the drive 6 of the motor vehicle 2, which leads to a corresponding starting impulse of the trailer 3. As a result, the trailer 3 oscillates horizontally, as shown by the double arrow 10. The measuring device 9 on the trailer 3 also experiences this oscillation. Thus, a device 11 can be implemented which detects the oscillation and then determines, for example, the mass m and / or the mass mL. The device can also have a computing unit 12 for this purpose, which carries out the evaluation. The mass m and / or the mass mL can then be displayed on a display device 13, which can be located at the driver's seat. The determination of the at least one mass m, mL of the vehicle 3 on the basis of the oscillation signal S is explained in more detail with reference to Figs. 2A to 2C.It is also possible that the starting impulse of the vehicle 3, in particular trailer 3, occurs against the braked vehicle 2, in particular towing vehicle 2, when the drive control 5 controls the drive 7 of the vehicle 3.
[0033] In this embodiment, the measuring device 9 is arranged directly on the vehicle 3. The measuring device 9 has an inertial sensor 16, which detects at least the component of the temporal change in the speed of the vehicle 3 directed in the direction of travel 15 of the vehicle 3. The vibration signal S can be this detected component or at least be based on it. The vibration signal S can be recorded and evaluated by the computing unit 12.
[0034] Fig. 2A shows a diagram illustrating a signal curve of the vibration signal S, wherein the signal curve is exemplary for an additional load m Lof 92 kg. Fig. 2B shows the waveform of the vibration signal S without the aforementioned additional load. Furthermore, Fig. 2C shows a diagram illustrating the signal I, which is sent to a drive control 4 of the drive 6 of the motor vehicle 2, wherein the signal waveforms shown in Figs. 2A and 2B are recorded in synchronized time by the measuring device 9.
[0035] In this case, the natural frequency is lower when the payload m is provided (Fig. 2A) than when the payload mL is not provided (Fig. 2B). For other payloads m L correspondingly different natural frequencies result.
[0036] Fig. 3A shows a diagram illustrating a signal curve of the measuring device 8, designed as a load cell 8, of a device 11 according to a possible embodiment of the invention. The load cell 8 can be integrated into a drawbar of the trailer 3, thus enabling a compact design. The device 11 is used in the combination 1 shown in Fig. 1. This can be done in addition to or as an alternative to the measuring device 9. Fig. 3A shows the signal curve for an additional load m L of 92 kg. Fig. 3B shows the diagram shown in Fig. 3A, where the signal curve is shown without the additional load m Lis shown. In this embodiment, a force measurement is carried out via the measuring device 8. A starting pulse or the like, triggered by the signal I, results in pulse-like acceleration which, viewed in the direction of travel 15, initially has a positive and then a negative sign. In particular, starting from a standstill and then braking can be caused, so that the trailer 3 oscillates in and against the direction of travel 15, which causes an oscillating coupling force F at the coupling of the trailer 3 to the motor vehicle 2, as shown in Fig. 3A and Fig. 3B.
[0037] Fig. 3C shows a diagram illustrating the absolute value of P1 (f) of the fast Fourier transform (FFT) of the respective natural angular frequencies f of the signal waveforms shown in Fig. 3A and 3B. For the case shown in Fig. 3A with an additional load m of 92 kg, curve 18 results with a maximum at approximately 4.68 Hz for an exemplary test measurement of a test setup. For the case shown in Fig. 3B without the additional load m, curve 19 results with a maximum at approximately 7.82 Hz, i.e., a significantly higher natural angular frequency, for the exemplary test measurement of a test setup.
[0038] In a method carried out by the device 11, the drive 6 of the motor vehicle 2, which is coupled to the vehicle 3 designed as a trailer 3, can be controlled by means of the drive control 4. In this case, the measuring device 8 can have at least one load cell 8 which detects the coupling force F acting in the direction of travel 15 of the vehicle 3. Specifically, in the method, the measuring device 8 can detect the component F of the coupling force acting in the direction of travel 15 of the vehicle 2 between the motor vehicle 2 and the trailer 3 coupled to the motor vehicle 2, so that the vibration signal S is obtained which is based on the component F of the coupling force acting in the direction of travel 15 of the vehicle 3.
[0039] In a preferred embodiment, based on the signal I sent to the drive control 4 of the drive 6, the drive 6 is controlled such that a specific torque pulse M acts on the vehicle 3. A damped natural angular frequency f of the vehicle 3 can then be determined based on the vibration signal S. Furthermore, the mass m, mL can be determined based on the damped natural angular frequency f. This is also further described with reference to Figs. 4A and 4B.
[0040] Fig. 4A shows a diagram illustrating a characteristic map 20 stored based on the natural angular frequencies f determined for various additional masses m, which can then be used to determine the mass according to a possible embodiment of the invention. This allows the total mass m of the vehicle 3 and / or the current additional mass mL to be determined. In this exemplary embodiment, the characteristic map is determined by several points, with values between these points being linearly approximated. Other approximations can also be used.
[0041] Fig. 4B shows a diagram illustrating the course of a stored exponential function 30, which can be used for mass determination according to another possible embodiment of the invention. The exponential function 30 can be determined by a curve fit to the specific natural angular frequencies shown in Fig. 4A.
[0042] Fig. 5A shows a diagram illustrating the determination of an additional mass mL using a characteristic map shown in Fig. 4A or an exponential function shown in Fig. 4B from a measured natural angular frequency during a measurement process in which the additional mass mL is located at the center of mass of the vehicle 3. Here, the mass determination is verified in the test setup with an additional load mL of 44.6 kg, resulting in a mass of 43.3 kg determined from the exponential function. The tire pressure in this case is 4.0 bar.
[0043] Fig. 5B shows a diagram that illustrates the determination of an additional mass mL using a characteristic map shown in Fig. 4A or an exponential function shown in Fig. 4B from a measured natural angular frequency in a further measurement process in which the additional mass mL is not located at the center of mass. Here, the mass determination is checked in the test setup with an additional load mL of 44.6 kg, whereby the mass determined from the exponential function is 39.9 kg. The tire pressure in this case is also 4.0 bar. Fig. 5C shows the diagram shown in Fig. 5A, wherein the measurement is carried out for a larger additional mass m arranged at the center of mass of the vehicle 3. Here, the mass determination is checked in the test setup with an additional load m of 77.6 kg, whereby the mass determined from the exponential function is 76.1 kg. The tire pressure in this case is again 4.0 bar.
[0044] Thus, in the method, the mass m, mL can be determined from the damped natural angular frequency f based on a stored characteristic map 20. Additionally or alternatively, the mass m, mL can be determined from the damped natural angular frequency f based on a stored exponential function 30. The mass m can, for example, be determined additively from the determined additional mass mL and an unladen weight of the vehicle 3. Furthermore, the mass m can also be determined directly, in which case the additional mass mL is then determined subtractively by subtracting the unladen weight.
[0045] The display device 13 can be provided in the motor vehicle 2, on which the determined mass m and / or the mass mL is displayed to the driver. This particularly preferably takes place before the actual start of the journey so that the driver can check whether the mass m and / or mL, for example, lies within predetermined limits that must be observed for operation of the vehicle combination 1 on public roads. One or both vehicles 2, 3 can be braked or unbraked. The measurement can also be integrated into the start-off process, for example by outputting signal I from a drive control to the drive 6, 7 right at the beginning. Especially with electric drives 6, 7, a precise adjustment of the torque pulse M is possible. The mass m is preferably the total mass of the vehicle 3. The device 11 can carry out the method.A computer program is provided that includes instructions that cause the device 11 to execute at least some of the described method steps. The computer program can be loaded onto the computing unit 12 if necessary and updated regularly if necessary. A data carrier signal can be used for this purpose, which the computer program transmits, for example, via a mobile internet connection.
[0046] The invention is not limited to the described embodiments.
Claims
Patent claims Method for determining at least one mass (m) of a vehicle (2, 3), in particular a trailer (3), further in particular an electrically driven trailer and / or a caravan, and / or a motor vehicle (2), further in particular an electrically driven motor vehicle and / or a mobile home, - wherein a signal (I) is sent to a drive control (4, 5) of a drive (6, 7), which causes the drive control (4, 5) to carry out a pulse-like speed change of the vehicle (2, 3) by means of the drive (6, 7), - wherein at least one vibration signal (S) of at least one measuring device (8, 9) is received, which describes a vibration (10) of the vehicle (2, 3) excited by the pulse-like speed change of the vehicle (2, 3), and - wherein a mass (m) of the vehicle (2, 3) is determined on the basis of the vibration signal (S). Method according to claim 1, characterized in that the drive (6) of a motor vehicle (2) coupled to a vehicle (3) designed as a trailer (3) is controlled by means of the drive control (4). Method according to claim 2, characterized in that at least one measuring device (8, 9) at least indirectly, in particular directly, detects a component (F) of the coupling force acting in the direction of travel (15) of the vehicle (2) between the motor vehicle (2) and the trailer (3) coupled to the motor vehicle (2), and that the vibration signal (S) is based on the component (F) of the coupling force acting in the direction of travel of the vehicle. Method according to claim 3, characterized in that the measuring device (8, 9) has at least one load cell (8) which detects the coupling force (F) acting in the direction of travel (15) of the vehicle (3). Method according to one of claims 1 to 4, characterized in that at least one measuring device (9) is arranged directly on the vehicle (2, 3) and that the measuring device (9) detects at least the component of the temporal change in the speed of the vehicle (2, 3) directed in the direction of travel (15) of the vehicle (2, 3) by means of at least one inertial sensor (16). Method according to one of claims 1 to 5, characterized in that based on the signal (I) sent to the drive control (4, 5) of the drive (6, 7), the drive control (4, 5) controls the drive (6, 7) such that a specific torque pulse (M) acts on the vehicle (2, 3).Method according to one of claims 1 to 6, characterized in that a damped natural angular frequency (f) of the vehicle (2, 3) is determined on the basis of the vibration signal (S), and in that the mass (m) is determined on the basis of the damped natural angular frequency (f). Method according to claim 7, characterized in that the mass (m) is determined from the damped natural angular frequency (f) on the basis of a stored characteristic map (20), or in that the mass (m) is determined from the damped natural angular frequency (f) on the basis of a stored exponential function (30). Method according to one of claims 1 to 8, characterized in that the signal (I) is sent to the drive control (4, 5) of the drive (6, 7) when the vehicle (2, 3) is at rest or is starting from a rest state. Method according to one of claims 1 to 9, characterized in that the determined mass (m) is displayed to a vehicle driver and / or that the total mass of the vehicle (2, 3) is determined as mass (m). Device (11) for a vehicle (2, 3), in particular a trailer (3), furthermore in particular an electrically powered trailer and / or a caravan, and / or a motor vehicle (2), furthermore in particular an electrically powered motor vehicle and / or a mobile home, with at least one measuring device (8, 9), wherein the device (11) is adapted to carry out a method according to one of claims 1 to 10. Computer program comprising instructions which cause the device (11) of claim 11 to carry out the method steps of a method according to one of claims 1 to 10. Data carrier signal which transmits the computer program according to claim 12.