Weighing device, method for determining the center of gravity of a motor vehicle and method for operating a motor vehicle

Abstract

The invention relates to a weighing device (14) for determining the center of gravity of a motor vehicle (12), having at least four weighing elements (16), in particular two weighing elements (16) each for each axis of the motor vehicle (12) to be measured, which are able to determine a respective measurement value representing the weight of the motor vehicle (12), having a computing device (20) which is able to receive the respective measurement values from the weighing elements (16) and to determine the center of gravity from the received measurement values, and having an adjusting mechanism (18) which is able to adjust the relative orientation of the weighing elements (16) to one another.

Description

TECHNICAL FIELD

[0001] The invention relates to a weighing device for determining the center of gravity of a motor vehicle, a method for determining the center of gravity of a motor vehicle, and a method for operating a motor vehicle. BACKGROUND

[0002] From DE 10 2011 079 668 B3 a control system for a motor vehicle is known, which has actuators for a wheel drive, a steering device and a chassis. The control system comprises a request stage with a plurality of detection units, each of which is designed to capture a setting value of a vehicle user. The control system further comprises a processing unit, which is designed to determine a temporary target movement vector for the motor vehicle or to determine a target movement vector for the motor vehicle from a temporary target movement vector and determined operating parameters. In addition, the control system comprises a check stage, which is assigned at least one regulation unit, by means of which a force vector is determined depending on the target movement vector and at least one predetermined parameter set for a predetermined system regulation function. In addition, the control system has a control stage, which is assigned a processing unit, which is designed to determine corresponding regulation parameters for the actuators depending on the determined force vector.

[0003] Furthermore, from DE 10 2013 016 488 A1 a motor vehicle is known, which comprises at least one driver assistance system for pre-computing prediction data on at least one future driving situation of the motor vehicle by evaluating self-data relating to the motor vehicle and environmental data relating to the surroundings of the motor vehicle. In this case, the motor vehicle is controllable by a driver in a first operating mode of the driver assistance system and in a second operating mode of the driver assistance system, the motor vehicle control is carried out autonomously by the driver assistance system without the need for driver intervention. The driver assistance system is designed to switch from the first operating mode to the second operating mode temporarily when a triggering condition is met. The driver assistance system is designed to determine limit values for vehicle parameters from movement trajectory data and driver characteristic data. The triggering condition or one of the triggering conditions is above or below a limit value. SUMMARY

[0004] It is the task of the present invention to provide a weighing device for determining the center of gravity of a motor vehicle, a method for determining the center of gravity of a motor vehicle, and a method for operating a motor vehicle, which allow a motor vehicle to be controlled with a high degree of vehicle stability.

[0005] According to the invention, this task is accomplished by a weighing device for determining the center of gravity of a motor vehicle having the features of claim 1, a method for determining the center of gravity of a motor vehicle having the features of claim 4, and a method for operating a motor vehicle having the features of claim 7. Advantageous designs with suitable inventive refinements are specified in the respective dependent claims and in the following description.

[0006] The application relates to a weighing device for determining the center of gravity of a motor vehicle, having at least four weighing elements, in particular two weighing elements for each axis of the motor vehicle to be weighed. In particular, one weighing element is provided for each end of each motor vehicle axis. By means of the weighing elements, a measurement value which characterizes the weight of the motor vehicle can be determined for each. In addition, the weighing device comprises a computing device, in particular an electronic computing device, by means of which the individual measurement values can be received from the weighing elements and by means of which the center of gravity can be determined from the received measurement values. Furthermore, the weighing device has an adjustment mechanism by means of which the relative orientation of the weighing elements to one another can be adjusted. This means that the weighing elements can be moved relative to one another by means of the adjustment mechanism, as a result of which the motor vehicle resting on the weighing elements can be tilted. Tilting of the motor vehicle causes the weight of the motor vehicle to be distributed differently to the individual weighing elements on which the motor vehicle is supported. When the weighing elements are moved relative to one another, the weight of the motor vehicle supported on the weighing elements is displaced, wherein the center of gravity of the motor vehicle can be determined by the electronic computing device by combining the relative displacement of the weight of the motor vehicle resting on the weighing elements with the respective relative orientation of the weighing elements to one another. The weighing device thus allows the center of gravity of the motor vehicle to be determined very simply, precisely and reliably.

[0007] In an advantageous embodiment of the application, it is provided that at least one wheel of the motor vehicle can be placed on each of the weighing elements. By means of the wheels, the motor vehicle can be supported on the weighing elements. In this case, at least one wheel is in particular placed directly on the respective corresponding weighing element, as a result of which the weight of the motor vehicle is borne by means of the weighing elements by the wheels. By means of the adjustment mechanism, the weighing elements can be moved individually relative to one another, as a result of which the motor vehicle supported on the weighing elements can be displaced, in particular tilted, very simply by adjusting the respective orientation of the weighing elements.

[0008] In an alternative advantageous design of the application, a support element is provided, the underside of which is supported on the weighing elements, the motor vehicle can be parked on the top side of the support element and the support element can be oriented three-dimensionally by means of the adjustment mechanism. The support element can in particular be integrated into the roadway and lie flush with the roadway in the relative orientation of the weighing elements to one another. The motor vehicle can be placed on the top side of the support element, wherein the weighing elements supporting the support element on the underside of the support element are arranged in correspondence with the individual free ends of the motor vehicle axes. The spatial orientation of the support element can be adjusted by means of the adjustment mechanism, wherein in each orientation the weighing elements lie against the underside of the support element and bear the weight of the support element or of the motor vehicle supported on the support element. The support element allows the motor vehicle to be placed very simply on the weighing device in such a way that the individual ends of the motor vehicle axes are assigned to the corresponding weighing elements.

[0009] The application also relates to a method for determining the center of gravity of a motor vehicle, wherein the motor vehicle is parked on a weighing device in such a way that each axle end of each motor vehicle axle corresponds to a respective weighing element of the weighing device to which it is assigned. The weighing device is in particular a weighing device as already described with respect to the weighing device of the application. In the method it is also provided that the relative orientation of the weighing elements is adjusted by means of an adjusting mechanism, wherein the weighing elements are arranged in at least two different orientations from one another and in each of the orientations a respective measurement value characterizing the weight of the motor vehicle is determined. This means that in the method the weighing elements are arranged in a first orientation relative to one another by means of the adjusting mechanism and a first measurement value characterizing the weight of the motor vehicle is determined, and subsequently the weighing elements are adjusted from the first orientation to a second orientation by means of the adjusting mechanism, in which second orientation a second measurement value characterizing the weight of the motor vehicle is determined by means of the respective weighing elements. By means of the adjusting mechanism the weighing elements can be arranged in further orientations in which further measurement values are determined by means of the respective weighing elements. In the method it is also provided that the measurement values are received by means of a computing device, in particular from the weighing elements, and that the center of gravity of the motor vehicle is determined from the measurement values. In this case the center of gravity of the motor vehicle can be calculated from the measurement values according to a mathematical method. It is thus provided in the method that the center of gravity of the motor vehicle is determined on the basis of the displacement of the weight of the motor vehicle resting on the weighing elements caused by the relative adjustment / displacement of the weighing elements relative to one another. The method allows the center of gravity of the motor vehicle to be determined particularly simply and accurately in the respective current load state of the motor vehicle.

[0010] In one refinement of the application it is provided that the weighing elements are arranged in three different orientations from one another by means of the adjusting mechanism. Each of the orientations corresponds to a respective state of the weighing device. In a first state in which the weighing elements are arranged in a first horizontal plane, a respective first measurement value characterizing the weight of the motor vehicle is measured by means of the weighing elements. In a second state in which the weighing elements are arranged in a second plane rotated about the motor vehicle transversely relative to the first plane, a respective second measurement value characterizing the weight of the motor vehicle is measured by means of the weighing elements. In a third state in which the weighing elements are arranged in a third plane rotated about the motor vehicle longitudinally relative to the first plane, a respective third measurement value characterizing the weight of the motor vehicle is measured by means of the weighing elements. In particular, the weighing device is placed in the first state, from the first state into the second state and from the second state into the third state one after the other. The weighing elements thus experience in time succession from one another the first orientation which corresponds to the first state, the second orientation which corresponds to the second state and the third orientation which corresponds to the third state. In the method, the motor vehicle placed on the weighing device is thus first oriented at least substantially horizontally, then rotated about the vehicle transversely and then rotated about the vehicle longitudinally. Displacement of the weight of the motor vehicle between the respective weighing elements thus occurs. By means of the electronic computing device, the current center of gravity of the motor vehicle is determined by means of the displacement of the weight of the motor vehicle determined from the measured measurement values when the weighing elements are adjusted. By having the weighing device go through these three states, the center of gravity of the motor vehicle can be determined simply, precisely and quickly.

[0011] In other designs of the application it is shown to be advantageous that the method steps of the method for determining the center of gravity of the motor vehicle are carried out for a saddle vehicle and for a saddle train comprising the saddle vehicle and a semitrailer, respectively. The center of gravity of the semitrailer can then be determined by means of the computing device from the center of gravity of the saddle vehicle and the determined center of gravity of the saddle train. This means that the saddle vehicle is placed on the weighing device and the center of gravity of the saddle vehicle is determined by carrying out the method. Furthermore, the entire saddle train comprising the semitrailer is placed on the weighing device and the center of gravity of the saddle train comprising the semitrailer is determined by means of the method. By calculating the difference between the determined center of gravity of the saddle vehicle and the center of gravity of the saddle train, the center of gravity of the semitrailer is determined by means of the electronic computing device. The respective determined center of gravity of the saddle vehicle and / or of the saddle train and / or of the semitrailer can be stored in the respective driver assistance system of the saddle train, in particular of the saddle vehicle or of the semitrailer, and be taken into account for the control of the saddle train, in particular of the saddle vehicle or of the semitrailer.

[0012] Furthermore, the application relates to a method for operating a motor vehicle, wherein a center of gravity of the motor vehicle is received by means of a driver assistance system, wherein the center of gravity is determined in accordance with the method as already described with respect to the method for determining a center of gravity of a motor vehicle according to the application. It is further provided in the method that the motor vehicle is controlled in accordance with the received center of gravity. In this case, it is in particular provided that a maximum front wheel steering angle and / or a steering angle velocity and / or a steering angle acceleration is adjusted in accordance with the received center of gravity. It is in particular provided that a maximum steering angle and / or a maximum steering torque is defined in accordance with the determined center of gravity. It is in particular provided in the method that the motor vehicle is controlled at least partially automatically, in particular fully automatically and thus autonomously, wherein the motor vehicle is in particular at least partially automatically controlled laterally and / or longitudinally. The method allows a very precise determination of the maximum physical limit range of the motor vehicle on the basis of the particularly precise center of gravity provided and enables a very advantageous control of the motor vehicle with full utilization of the maximum physical limit range.

[0013] It is shown to be particularly advantageous in this connection that, for the control of the motor vehicle, a steering angle and / or a steering velocity and / or a steering torque is selected which, in terms of its resultant on the respective wheels of the motor vehicle, is inhibited from exceeding a predetermined adhesion limit. For the determination of the adhesion limit, it is in particular possible to select the camber friction circle as a basis for the determination. This means that the adhesion limit is determined in accordance with the camber friction circle. It is thus provided in the method that the steering angle and / or the steering velocity and / or the steering torque is selected in such a way that an exceeding of the adhesion limit on each motor vehicle wheel is at least substantially avoided. Thereby, a very high vehicle stability can be ensured in the control of the motor vehicle.

[0014] It is shown to be advantageous in other designs of the application that a stability limit of the motor vehicle is determined in accordance with the received center of gravity and that a steering angle and / or a steering velocity and / or a steering torque for the motor vehicle is selected in accordance with the stability limit. In particular, a steering angle and / or a steering velocity and / or a steering torque is selected which, with respect to the resulting inclination angle, is inhibited from exceeding the stability limit. The motor vehicle stability limit is thus determined in accordance with the received center of gravity of the motor vehicle as to where it is located. Furthermore, the steering angle and / or the steering velocity and / or the steering torque is selected in such a way that an inclination of the motor vehicle beyond the stability limit is inhibited, whereby a rollover of the motor vehicle can be at least substantially avoided.

[0015] It is advantageous in other designs of the application that the steering angle and / or the steering speed and / or the steering torque for the motor vehicle is selected in dependence on the limit of the safe driver's handling ability. This means that the limit of the safe driver's handling ability is determined and the steering angle and / or the steering speed and / or the steering torque is then selected such that it is not exceeded by the limit of the safe driver's handling ability. In particular, the movement trajectory resulting from the steering angle and / or the steering speed and / or the selected steering torque is determined, wherein the steering angle and / or the steering speed and / or the steering torque is selected such that it is not exceeded by the limit of the safe driver's handling ability with respect to the resulting movement trajectory. It is thereby ensured that the safe driver can at any time intervene in the motor vehicle control, whereby dangerous situations can be overcome and the danger of an accident can be kept low. BRIEF DESCRIPTION OF DRAWINGS

[0016] Further advantages, features and details of the application result from the following description of preferred embodiments and in conjunction with the drawings. The features mentioned above and those to be mentioned below and / or those shown in the drawings alone or in any combination are essential for the invention, where:

[0017] Figure 1 a top view of a road for motor vehicles is shown, in which a weighing device according to a first embodiment and a weighing device according to a second alternative embodiment are integrated;

[0018] Figures 2a-2b a side view of a weighing device according to a second embodiment is shown, in which a motor vehicle is parked on the weighing device, wherein each axle end of each motor vehicle axle is assigned a load cell of the weighing device and the load cell is designed to measure a respective measurement value representing the weight of the motor vehicle, wherein the load cells are arranged in a first orientation relative to each other in Figure 2a and in a second orientation relative to each other in Figure 2b and measure a respective first measurement value in the first orientation and a respective second measurement value in the second orientation, and the motor vehicle's center of gravity is determined by means of an electronic computing device from the first measurement value and the second measurement value.

[0019] Figure 3A side view of a weighing device according to a first embodiment is shown, wherein the weighing device comprises a support which is placed on weighing elements and on which motor vehicles can be supported, wherein each motor vehicle axle is assigned at least one weighing element per axle end, wherein by means of the weighing elements a measurement value can be acquired which characterizes the respective motor vehicle weight, and by means of an adjusting mechanism of the weighing device the support can be arranged in different orientations by the weighing elements on which the support is supported, wherein in each orientation of the support a respective measurement value can be measured by means of the weighing elements and by means of an electronic computing device the motor vehicle center of gravity can be determined from the measurement values in the different orientations of the support;

[0020] Figure 4 Method steps of a motor vehicle operating method are shown. DETAILED DESCRIPTION

[0021] Figure 1 A road 10 for motor vehicles 12, in particular trucks, is shown. Integrated in the road 10 is a weighing device 14. By means of the weighing device 14 the weight and the center of gravity of the motor vehicle 12 can be determined. Figure 1 Two different embodiments of the weighing device 14 integrated into the road 10 are shown. The first embodiment of the weighing device 14 is shown in a side view in Figure 3 The second embodiment of the weighing device 14 is shown in a side view in Figure 2a and 2b The weighing device 14 comprises in each embodiment a plurality of weighing elements 16, in particular one weighing element 16 per axle end of each motor vehicle 12 axle. By means of each weighing element 16 a measurement value can be determined which characterizes the weight of the motor vehicle 12. The weighing device 14 further comprises an adjusting mechanism 18 by means of which the orientation of the weighing elements 16 relative to one another can be adjusted. In order to ensure that the motor vehicle 12 can be reliably supported on the weighing elements 16 in each orientation of the weighing elements 16, it is provided that by means of the adjusting mechanism 18 the weighing elements 16 are arranged in the same plane according to each orientation of the weighing elements 16 relative to one another. In each different orientation of the weighing elements 16 relative to one another a measurement value can be acquired which corresponds to the orientation and characterizes the weight of the motor vehicle 12. The measurement values can be provided by the weighing elements 16 to an electronic computing device 20 of the weighing device 14. The electronic computing device 20 is shown here schematically in a block. By means of the electronic computing device 20 the center of gravity of the motor vehicle 12 can be determined from the received measurement values. Here, the weighing device 14 is supported on a base 28, the distance of the weighing elements 16 relative to the base can be adjusted by means of the adjusting mechanism 18 in order to orient the weighing elements 16 relative to one another.

[0022] The weighing device 14 can be designed as shown in Figure 2a and 2bThe arrangement shown is for placing the wheels 22 of the motor vehicle 12, which are assigned to the axle ends of the respective motor vehicle 12, directly onto the weighing element 16. This means that at least one wheel 22 of the motor vehicle 12 is supported on each of the weighing elements 16. In this case, as in Figure 1 As can be clearly seen, each weighing element 16 can be embedded in the road 10 and thus flush with the road 10 in at least one orientation relative to each other. Figure 3 In a first alternative design of the weighing device 14 shown, the weighing device 14 includes a support member 24 supported on the weighing element 16. The motor vehicle 12 can be supported on the support member 24. In this case, the motor vehicle 12 can be secured, for example, by means of wheel wedges 26 to prevent it from rolling off the support member 24. To enable simple and accurate determination of the center of gravity of the motor vehicle 12 using the weighing device 14, the weighing element 16 is arranged in at least two different orientations by means of an adjustment mechanism 18, and a corresponding measurement characterizing the weight of the motor vehicle 12 is measured in each of these orientations.

[0023] Therefore, in order to determine the center of gravity of the motor vehicle 12 using the weighing device 14, the motor vehicle 12 is supported on the weighing device 14, and in particular, each axle end of the motor vehicle 12 is correspondingly assigned to a weighing element 16. Next, the weighing elements 16 are oriented relative to each other in different orientations using the adjusting mechanism 18, particularly in the same plane, and for each orientation, various measurements characterizing the weight of the motor vehicle 12 are measured using the weighing elements 16. Here, the weighing elements 16 are adjusted to a first state using the adjusting mechanism 18, the first state being... Figure 2a The method is exemplarily shown in the first state, and a first measurement value characterizing the weight of the motor vehicle 12 is measured using the weighing element 16. Furthermore, the method specifies that the weighing element 16 is adjusted to a second state using the adjusting mechanism 18. This second state is specific to the second embodiment of the weighing device 14. Figure 2b The first embodiment shown in the figure and for weighing device 14 is in Figure 3 The following is shown. In the second state of the weighing device 14, a corresponding second measurement value characterizing the weight of the motor vehicle 12 is obtained by means of the weighing element 16. In addition, the adjustment mechanism 18 is provided here for adjusting the weighing element 16 to a third state, in which a corresponding third measurement value characterizing the weight of the motor vehicle 12 can be obtained by means of the weighing element 16.

[0024] In the first state, the weighing elements 16 are arranged in a first horizontal plane which here extends parallel to the base 28. In the second state, the weighing elements 16 are arranged in a second plane which is rotated relative to the first plane about the vehicle transverse direction y of the motor vehicle 12. In the third state, the weighing elements 16 are arranged in a third plane which is rotated relative to the first plane about the vehicle longitudinal direction x of the motor vehicle 12. The sequence of the states of the weighing elements 16 achieved by means of the adjusting device 18 is freely selectable. In particular, the adjusting device 18 is designed to place the weighing elements 16 in each state one after the other in order to be able to measure the respective measurement values corresponding to the orientations. The respective first measurement value, second measurement value and third measurement value can be received by means of the electronic computing device 20. The center of gravity of the motor vehicle 12 can be determined by means of the electronic computing device 20 from the first measurement value, the second measurement value and the third measurement value.

[0025] In particular, the center of gravity of the motor vehicle 12 as a separate saddle vehicle and the center of gravity of the motor vehicle 12 as a saddle train comprising the saddle vehicle and the semitrailer can be determined by means of the weighing device 14. In order to determine the center of gravity of the semitrailer, the center of gravity of the saddle train comprising the saddle vehicle and the semitrailer can be determined by means of the weighing device 14 and separately from this the center of gravity of the separate saddle vehicle without the semitrailer. By calculating the difference between the respective centers of gravity of the entire saddle train and the separate saddle vehicle, the center of gravity of the semitrailer can be determined by means of the electronic computing device 20.

[0026] Figure 4A method diagram for a method for operating a motor vehicle 12 is shown. In this method it is provided that, by means of a driver assistance system, a center of gravity of the motor vehicle 12 is received in a first method step VI, which is determined by means of an electronic computing device 20. In a second method step V2, a steering angle and / or a steering speed and / or a steering torque for the motor vehicle 12 is selected by means of the driver assistance system. In a third method step V3, the motor vehicle 12 is controlled by means of the driver assistance system in accordance with the selected steering angle and / or the selected steering speed and / or the selected steering torque. In order to allow a high vehicle stability of the motor vehicle 12 to be achieved, in particular in the state of at least partial automatic, in particular full automatic, operation of the motor vehicle 12, it is provided that an adhesion limit of the motor vehicle 12, a stability limit of the motor vehicle 12 and a limit of the ability to control the motor vehicle 12 by a safe driver are determined. In particular, the steering angle and / or the steering speed and / or the steering torque is selected in such a way that the resultant force on the individual wheels 22 of the motor vehicle 12 is not higher than the predetermined adhesion limit. Furthermore, the stability limit of the motor vehicle 12 is determined in accordance with the received center of gravity and the steering angle and / or the steering speed and / or the steering torque for the motor vehicle 12 is selected in such a way that tilting of the motor vehicle 12 beyond the stability limit is prohibited. Furthermore, the steering angle and / or the steering speed and / or the steering torque for the motor vehicle 12 is selected in such a way that the resulting movement trajectory of the motor vehicle 12 does not exceed the limit of the ability to control the motor vehicle 12 by a safe driver.

[0027] The method for determining the center of gravity of the motor vehicle 12 and the method for operating the motor vehicle 12 are based on the insight that the lateral dynamics of an autonomously driving truck are an important design criterion. It is necessary, in particular in driving-dynamic critical situations, not to exceed the limits of the driving dynamics. Hitherto, in the field of trucks, there are regulation systems, such as electronic stability control systems (ESP), for preventing driving-dynamic limit situations. However, these regulation systems are mostly designed conservatively because the center of mass of the individual vehicles is not known. In this case, brake interventions are made at a point at which the driving-dynamic critical situation has not yet been reached. It is thus possible that a technically feasible avoidance and thus a prevention of an accident cannot be achieved. Furthermore, a safe driver is not taken into account in the calculation of the steering torque and the steering angle.

[0028] In order to calculate the steering angle and / or the steering torque, which can be output parameters of the autonomous system and at the same time input parameters of the steering system of the motor vehicle 12, three criteria should be fulfilled. If one of the two characteristic parameters, i.e. the steering angle or the steering torque, is above the respective maximum range for the respective criterion, the characteristic parameter is limited. The first criterion is the adhesion limit, the second criterion is the stability limit and the third criterion is the limit of the ability to control the motor vehicle 12 by a safe driver.

[0029] The cam circle, also called the cam friction circle, represents the "possible total force to be distributed as side slip force and drive / braking force on the wheels 22 of the motor vehicle 12". The steering angle and the steering speed and the steering torque for setting the steering angle should not exceed the adhesion limit. The combination of the center of gravity and the occurring centrifugal forces of the motor vehicle 12 is decisive for the stability limit of the motor vehicle 12. Especially in the case of a truck, the stability limit should be reached before the adhesion limit. The center of gravity of the motor vehicle 12 should therefore be known in order to be able to determine the stability limit very precisely. In particular, the center of gravity is determined by means of the described method for determining the center of gravity of the motor vehicle 12. The driving dynamic model serves as a supplement to the determined stability limit and sets the maximum lateral force or the maximum steering angle or the maximum steering angle speed, from which the steering torque can be derived.

[0030] The self-driving vehicle, here the self-driving motor vehicle 12, is monitored during the development phase by a safety driver. He should intervene and correct the current steering angle in the event of an incorrect assessment. The respective steering angle or force or the steering torque for adjusting the steering angle required by the autonomous system of the motor vehicle 12 should not exceed the limit of the control ability of the safety driver. The described method of operating the motor vehicle 12 allows the maximum physical limit range to be fully utilized, whereby a very high vehicle safety can be achieved. In addition, the safety driver can be taken into account in the autonomous driving system cooperation.

[0031] The described weighing device 14 and the method for determining the center of gravity of the motor vehicle 12 by means of the weighing device 14 is also based on the insight that, in order to take into account all hazardous situations as optimally as possible in a self-driving vehicle, it is necessary to identify the lower and upper limits of the steering device performance and the braking performance. The relevant parameter is the center of gravity of the motor vehicle 12. The center of gravity can be changed by exchanging structures, for example like a salt spreader or a lawn mower, for example and especially in utility vehicles. Other examples of structures for changing the center of gravity of the motor vehicle 12 are roof boxes and running wheel arches in a passenger car as a motor vehicle 12. The result of the determination of the center of gravity of the motor vehicle 12 can be transmitted to the motor vehicle 12 manually or automatically to be taken into account or processed by its dynamic adjustment system. By means of the weighing device 14, in particular the electronic computing device 20, a delta calculation can be carried out. In the delta calculation, the center of gravity of a semi-trailer of a horse-drawn vehicle as a motor vehicle 12 can be calculated in a first step by measuring the horse-drawn vehicle as a motor vehicle 12 and subsequently by measuring the entire horse-drawn vehicle train as a motor vehicle 12.

[0032] In order to determine the center of gravity of the motor vehicle 12 in the vehicle longitudinal direction x, the vehicle transverse direction y and the vehicle vertical direction z, in particular three measurements are carried out. In a first measurement, all load cells 16 are arranged in a first plane parallel to the base 28, such that the motor vehicle 12 is oriented horizontally. In this case, the respective axes of the motor vehicle 12 are placed on the corresponding two load cells 16. By means of the load cells 16, the respective weight on the axle ends of the axes of the motor vehicle 12 is measured. In a second measurement, the load cells 16 are adjusted relative to one another, thereby tilting the motor vehicle 12 about the vehicle transverse direction y. As a result, the motor vehicle 12 is oriented obliquely upwards in the vehicle longitudinal direction x. In a third measurement, the load cells 16 are only lifted on one side of the motor vehicle 12, thereby tilting the motor vehicle 12 about the vehicle longitudinal direction x. As a result, the motor vehicle 12 is arranged obliquely in the vehicle transverse direction y. After the measurements, the center of gravity of the motor vehicle 12 can be determined mathematically in the vehicle longitudinal direction x, the vehicle transverse direction y and the vehicle vertical direction z. In the case of a saddle vehicle train, the center of gravity coordinates and the force of the motor vehicle 12 can be fed to the towing vehicle and / or the semitrailer. In a vehicle with multiple structures, the center of gravity coordinates and the force can be fed to the respective vehicle, wherein individual entries can be made in the vehicle, in particular the motor vehicle 12, for each structure.

[0033] In order to implement this in the motor vehicle 12, the motor vehicle 12 can first be measured by means of the weighing device 14, as described. The center of gravity coordinates and the center of gravity force of the motor vehicle 12 and of the optionally present semitrailer can then be notified to the center of gravity provider of the motor vehicle 12 and / or the semitrailer or trailer by means of a man-machine interface or a machine- machine interface, for example a remote technology in a remote control device. The center of gravity provider provides information about the vehicle start or vehicle calibration moment of the motor vehicle 12 to a driving regulation system. The driving regulation system can be in particular an electronic stability control of an electronic stability program. The driving regulation system can use this information to keep the saddle vehicle train within the stability limit and at the same time to use this limit range as optimally as possible. The determined center of gravity can be used by the driving dynamics regulation system to keep the motor vehicle 12 within the stability limit. The motor vehicle 12 can be connected to the main controller of the trailer by means of a controller for the trailer socket. The man-machine interface, the machine-machine interface, the center of gravity provider of the motor vehicle 12 and the controller for the trailer socket can be connected to one another by means of an E / E network.

[0034] Overall, the measurement of the motor vehicle 12 can be carried out in the wheel hub by means of the weighing device 14. As a result, a very advantageous vehicle safety can be achieved.

[0035] Overall, the application shows how the center of gravity of the motor vehicle 12 can be determined and how the maximum front wheel steering angle, the steering angle velocity and the steering angle acceleration can be determined while observing the vehicle stability of an autonomous driving truck.

Claims

1. A weighing device (14) for determining the center of gravity of a semitrailer of a tandem, wherein The weighing device has at least four weighing elements (16) by means of which a first measurement value characterizing the weight of the saddle vehicle and a second measurement value characterizing the weight of the saddle train can be determined, a computing device (20) which can receive the respective first and second measurement values from the weighing elements (16) and can determine the center of gravity of the saddle vehicle and the center of gravity of the saddle train from the received first and second measurement values, respectively, and can determine the center of gravity of the semitrailer from the center of gravity of the saddle vehicle and the center of gravity of the saddle train, and an adjustment mechanism (18) which can adjust the mutual relative orientation of the weighing elements (16), wherein the wheels of the motor vehicle are supported directly on the weighing elements and each weighing element is embedded in the roadway.

2. A weighing device according to claim 1, characterized in that At least one wheel (22) of the saddle train can be supported on each of the weighing elements (16).

3. The weighing device of claim 1, wherein, A support element (24) is provided, the underside of which is supported on the weighing elements (16), the saddle train can be parked on the top side of which, and which can be oriented three-dimensionally by means of the adjustment mechanism (18).

4. The weighing device of claim 1, wherein, Two weighing elements (16) are provided for each axle of the saddle train to be measured.

5. A method for determining the center of gravity of a motor vehicle (12), wherein a) the motor vehicle (12) is parked on a weighing device (14) in such a way that a respective weighing element (16) of the weighing device (14) is assigned to each end of each axle of the motor vehicle (12), wherein the wheels of the motor vehicle are supported directly on the weighing elements and each weighing element is embedded in the roadway; b) the relative orientation of the weighing elements (16) is adjusted by means of an adjustment mechanism (18), wherein the weighing elements (16) are arranged in at least two different relative orientations from one another and in each orientation a respective measurement value characterizing the weight of the motor vehicle (12) is measured, and c) the measurement values are received by means of a computing device (20) and the center of gravity of the motor vehicle (12) is determined from the measurement values; wherein the method steps a) to c) are carried out for a saddle vehicle and for a saddle train comprising a saddle vehicle and a semitrailer, respectively, and the center of gravity of the semitrailer is determined from the center of gravity of the saddle vehicle and the center of gravity of the saddle train by means of the computing device (20).

6. The method of claim 5, wherein, By means of the adjustment mechanism (18), the weighing elements (16) are arranged in three different relative orientations from one another, wherein o in a first state in which the weighing elements (16) are arranged in a horizontal first plane, a respective first measurement value characterizing the weight of the motor vehicle (12) is measured by means of the weighing elements (16), o in a second state in which the weighing elements (16) are arranged in a second plane rotated about the vehicle transverse direction (y) of the motor vehicle (12) relative to the first plane, a respective second measurement value characterizing the weight of the motor vehicle (12) is measured by means of the weighing elements (16), and o a third measurement value characterizing the weight of the motor vehicle (12) is measured by means of the load cell (16) in a third state in which the load cell (16) is arranged in a third plane which is rotated relative to the first plane about the vehicle longitudinal direction (x) of the motor vehicle (12).

7. A method for operating a motor vehicle (12), wherein The center of gravity of the motor vehicle (12) determined in the method according to one of claims 5 to 6 is received by means of a driver assistance system and the motor vehicle (12) is controlled in accordance with the received center of gravity.

8. The method of claim 7, wherein, The steering angle and / or the steering speed and / or the steering torque is selected for the control of the motor vehicle (12) in such a way that the resultant force on the individual wheels (22) of the motor vehicle (12) is inhibited from exceeding a predetermined adhesion limit.

9. The method according to claim 7 or 8, characterized in that, The stability limit of the motor vehicle (12) is determined in accordance with the received center of gravity and the steering angle and / or the steering speed and / or the steering torque for the motor vehicle (12) is selected in accordance with the stability limit.

10. The method according to claim 7 or 8, characterized in that, The steering angle and / or the steering speed and / or the steering torque for the motor vehicle (12) is selected in accordance with the limit of the ability to control of a safe driver.

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