Ultrasonic sensor system for detecting at least one object located in environment of vehicle, and vehicle having ultrasonic sensor system
By adjusting the installation angle and amplitude threshold of the ultrasonic sensor, the problem of the small amplitude of the echo signal when detecting the side objects of the vehicle in the prior art is solved, and a wider detection range and higher sensitivity are achieved, and the side objects can be effectively identified.
Patent Information
- Application Number
- CN202380082849.5
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Priority Date
- 2022-12-01
- Filing Date
- 2023-11-20
- Publication Date
- 2025-08-05
AI Technical Summary
When detecting objects on the side of the vehicle, the existing ultrasonic sensor system has the problem that the echo signal amplitude is small and difficult to be analyzed and utilized, especially when there is a large angle between the main detection direction and the detection direction.
Using an ultrasonic sensor system, the main detection direction of the first ultrasonic sensor is at a first angle to the longitudinal axis of the vehicle, and the main detection direction of the second ultrasonic sensor is at a second angle to the longitudinal axis, the first angle is smaller than the second angle, and the amplitude threshold of the first ultrasonic sensor is lowered, or the amplitude threshold of the two ultrasonic sensors is lowered relative to the normal mode to enhance the detection range and sensitivity.
It improves the detection range and sensitivity of the ultrasonic sensor, can effectively detect objects located on the side of the vehicle, reduces the impact of interference signals, and enhances the recognition ability of the side objects.
Smart Images
Figure CN120435672A_ABST
Abstract
Description
Technical Field
[0001] The invention relates to an ultrasonic sensor system for detecting at least one object in the environment of a vehicle. Background Art
[0002] Ultrasonic sensor systems are widely used in the field of vehicle environmental monitoring (for example, in the form of parking assistance systems) to detect the vehicle's surroundings. Typically, conventional ultrasonic sensor systems operate according to the pulse-echo principle. An electrical signal stimulates the ultrasonic sensor's diaphragm, which acts as a transducer, to vibrate, and these vibrations are emitted as sound. The sound propagates through the air until it strikes an object in the surroundings. The object's surface reflects the sound, causing backscattering in the direction of the ultrasonic sensor. If the backscattered sound strikes the ultrasonic sensor's diaphragm, it causes it to vibrate and generates an electrical signal on the piezoelectric element, which can be detected and analyzed by the ultrasonic sensor system. The time of flight from the emission to the return of the sound can be measured. Using the known propagation speed of sound, the distance between the ultrasonic sensor and the object causing the backscattering sound can be determined. This information can be used, for example, to find a parking space and protect the vehicle's flanks against collisions.
[0003] Typically, an ultrasonic sensor system has a plurality of ultrasonic sensors that are oriented differently in their main detection directions. Thus, for example, one ultrasonic sensor may point more forward, while another ultrasonic sensor may point more to the side.
[0004] A problem with such ultrasonic sensor systems in the prior art is that, in order to detect objects to the side of the vehicle, a large angle exists between the main detection direction and the detection direction when the ultrasonic sensor is oriented more forward. As a result, the amplitude of the detectable ultrasonic echo signal becomes very small and, due to the typically existing amplitude threshold, is no longer usable for evaluation by conventional ultrasonic sensors. Summary of the Invention
[0005] The aforementioned problems of the corresponding known systems are intended to be solved by the present invention.
[0006] The present invention relates to an ultrasonic sensor system for detecting at least one object in the environment of a vehicle, wherein the ultrasonic sensor system has at least one first ultrasonic sensor for emitting a first ultrasonic signal and receiving a first ultrasonic echo signal, and a second ultrasonic sensor for emitting a second ultrasonic signal and receiving the second ultrasonic echo signal, wherein the first ultrasonic sensor and the second ultrasonic sensor can be mounted on the vehicle in such a way that a first main detection direction of the first ultrasonic sensor encloses a first angle with respect to a longitudinal axis of the vehicle, and a second main detection direction of the second ultrasonic sensor encloses a second angle with respect to the longitudinal axis, wherein the first angle is smaller than the second angle, and wherein the ultrasonic sensor system is configured to select a first amplitude threshold value of the first ultrasonic sensor for the first ultrasonic echo signal to be smaller than a second amplitude threshold value of the second ultrasonic sensor for the second ultrasonic echo signal, or to reduce the first amplitude threshold value and / or the second amplitude threshold value relative to a normal mode.
[0007] Advantageously, by lowering the amplitude threshold of the first ultrasonic sensor, the detection range of the ultrasonic sensor can be increased. This detection range can also be used to detect objects to the side of the vehicle, for example, even though the first ultrasonic sensor is oriented more toward the longitudinal axis of the vehicle, i.e., more toward the front or rear, relative to its main detection direction, than the second ultrasonic sensor. Consequently, ultrasonic echo signals arriving at the first ultrasonic sensor from directions that form a significant angle relative to its main detection direction can also be detected and evaluated. This means that lowering the amplitude threshold increases the sensitivity of the ultrasonic sensor. Alternatively, the amplitude thresholds of both ultrasonic sensors can be lowered compared to a normal mode, which focuses the detection range of each ultrasonic sensor substantially along its main detection direction.
[0008] The amplitude of the ultrasonic echo signal is strongly dependent on the detection direction relative to the main detection direction of the ultrasonic sensor. The greater the difference, the smaller the amplitude. The high sensitivity of the first ultrasonic sensor ensures that it can also detect a stable signal from the side.
[0009] For example, the vehicle can be a passenger car, a truck or also a particularly motorized two-wheeled vehicle.The vehicle's surroundings can be understood as everything outside the actual vehicle geometry, such as parking spaces in front of, behind or beside the vehicle.
[0010] An object can be understood as an item in the vehicle's surroundings, such as another vehicle, a curb, or a wall. The longitudinal axis is the axis of a body that corresponds to the direction of its greatest extent. The longitudinal axis is also typically the approximate axis of symmetry of the body. In a vehicle, the longitudinal axis points forward and extends centrally through the vehicle.
[0011] In particular, the ultrasonic sensor may include an ultrasonic transceiver for emitting ultrasonic signals or receiving ultrasonic echo signals. For example, the first ultrasonic sensor and the second ultrasonic sensor may be mounted on a bumper or other body component in a vehicle. In particular, for example, the first ultrasonic sensor may be oriented parallel or approximately parallel to the longitudinal axis of the vehicle, while the second ultrasonic sensor may be oriented perpendicular or approximately perpendicular to the longitudinal direction of the vehicle. Furthermore, the two ultrasonic sensors may be arranged on a common side relative to the longitudinal axis of the vehicle, i.e., either to the right or to the left of the longitudinal axis.
[0012] Typically, the main detection direction is understood to be the direction perpendicular to the diaphragm of the ultrasonic sensor. In this direction, the ultrasonic sensor can transmit and receive optimally, meaning that the amplitude of the corresponding signal in or coming from this direction is highest compared to signals at a certain angle relative to the main detection direction. The angle between the main detection direction of the ultrasonic sensor and the longitudinal axis of the vehicle is specified so that it is always minimal and can therefore be a maximum of 90°.
[0013] Unless otherwise stated, the angles, directions, spacings, distances and distances given below refer essentially to a horizontal plane relative to the vehicle.
[0014] Furthermore, the ultrasonic sensor system may include a processing unit for signal processing and further distribution, which may be designed, for example, as a microcontroller and may include corresponding computing and storage devices. For example, the processing unit may also be configured to determine the distance and direction of an object relative to the ultrasonic sensor.
[0015] The amplitude threshold value can be understood as a threshold value, wherein signal components with an amplitude less than the threshold value are no longer taken into account by the ultrasonic sensor system, but are classified as insignificant. Typically, the amplitude threshold value is used to filter out interfering signals, which usually have a small amplitude.
[0016] In particular, the ultrasonic sensor system may also include one or more additional ultrasonic sensors, wherein the amplitude thresholds of the additional ultrasonic sensors are adjusted such that, at additional angles between the main detection direction and the longitudinal axis that are smaller than the first angle, the amplitude threshold is selected to be further reduced compared to the first amplitude threshold. For additional angles between the first and second angles, the amplitude threshold is correspondingly selected to be between the first and second amplitude thresholds. Conversely, if the additional angle is between the second angle and 90°, the amplitude threshold is selected such that it is greater than the second amplitude threshold.
[0017] One embodiment of the present invention provides that the ultrasonic sensor system is designed to filter a first ultrasonic echo signal received by means of the first ultrasonic sensor, in particular by means of a Kalman filter and / or by means of a Ransack algorithm.
[0018] Advantageously, interference signals can be filtered from the ultrasonic echo signal. These interference signals may be present more strongly in the first ultrasonic echo signal than in the second ultrasonic echo signal due to the lower amplitude threshold of the first ultrasonic sensor. This also increases the interference rate of the ultrasonic sensor, which is caused, for example, by ground noise, interfering sounds, or sensor noise, with the sensitivity of the ultrasonic sensor.
[0019] Another embodiment of the present invention provides that the first ultrasonic sensor and the second ultrasonic sensor can be mounted on the vehicle such that the first ultrasonic sensor has a first distance from the longitudinal axis of the vehicle and the second ultrasonic sensor has a second distance from the longitudinal axis of the vehicle, wherein the first distance is smaller than the second distance.
[0020] The advantage here is that ultrasonic sensors that are arranged closer to the longitudinal axis (which can also be referred to as inner ultrasonic sensors and tend to point more forward or backward in their main detection direction relative to the vehicle) can still assist ultrasonic sensors that are arranged further away from the longitudinal axis (which can also be referred to as outer ultrasonic sensors and tend to point more to the side in their main detection direction) in identifying objects located to the side of the vehicle.
[0021] Another advantage is that the ultrasonic sensors have different distances from lateral objects, so the ultrasonic echo signals can also be used to determine certain height information about the object, for example, whether the object can be classified as high or low. By adding an internal ultrasonic sensor to the lateral object formation, a stronger criterion can be achieved than when only the laterally oriented external ultrasonic sensors are used for object detection.
[0022] Another advantage of using interior ultrasonic sensors for detecting lateral objects is that they can still detect low objects, such as curbstones, even at a short distance between the vehicle and the object, something that might not be possible with exterior ultrasonic sensors. Exterior ultrasonic sensors can detect curbstones up to a distance of approximately 50 cm from the ultrasonic sensor, as curbstones, due to their low height, lie outside the vertical sensor detection angle at a short sensor-to-curb distance. However, due to the greater distance between the interior ultrasonic sensor and the vehicle itself, a 50 cm detection distance from the interior ultrasonic sensor often only corresponds to an actual distance of 10 to 20 cm from the vehicle side to the object, depending on the ultrasonic sensor's placement on the vehicle. This significantly reduces the minimum detection distance for low objects on the side of the vehicle.
[0023] Internal ultrasonic sensors typically see objects located to the side at a wide angle, which can result in very low measured amplitudes. Therefore, achieving adequate performance for detecting objects located to the side requires a very sensitive sensor system. Therefore, the amplitude threshold of the internal ultrasonic sensor is lowered compared to normal mode and is particularly preferably set lower than that used for the external ultrasonic sensor. This can extend the ultrasonic sensor's field of view, or detection range, to up to 180°. Ideally, the implemented amplitude threshold should also filter out ground noise and sensor noise.
[0024] In this context, a distance is to be understood as the length of the shortest horizontal connection between the respective sensor location and the longitudinal axis of the vehicle.
[0025] Height information can be understood as information about a detected object, indicating whether the object is high or low. Low is defined as an object whose height does not protrude into the horizontal plane defined by the ultrasonic sensor. Typically, such low objects can still be driven over without causing damage, such as curbstones. Conversely, if an object penetrates the horizontal plane defined by the ultrasonic sensor, it is classified as high. Typically, such high objects cannot be driven over without causing damage, such as walls or pillars.
[0026] According to one embodiment of the present invention, the ultrasonic sensor system is configured to determine a first distance between a first ultrasonic sensor and an object and a second distance between a second ultrasonic sensor and the object, and to compare the difference between the first distance and the second distance with a distance between the first ultrasonic sensor and the second ultrasonic sensor, which is located perpendicular to the longitudinal axis of the vehicle.
[0027] Advantageously, for example, a comparison can be used to verify whether an object in the vehicle's surroundings is located in front of, behind, or beside the vehicle. It can be assumed that the object is beside the vehicle if the distance between the first ultrasonic sensor and the object essentially corresponds to the sum of the distance between the second ultrasonic sensor and the object and the distance between the first ultrasonic sensor and the second ultrasonic sensor, perpendicular to the longitudinal axis of the vehicle.
[0028] This prevents incorrect object creation from being performed.
[0029] In order to achieve a higher robustness and performance of the verification, the check can also be averaged over the last x sensor events of the two ultrasonic sensors, wherein x can be determined empirically.
[0030] In this context, the term "distance" should be understood to mean the length of the shortest connection between the respective sensor position and the longitudinal axis of the vehicle. If possible, this length can in particular only have a horizontal component of the road section.
[0031] In this context, distance is to be understood as the difference in position between the respective sensor positions perpendicular to the vehicle's longitudinal axis. In particular, this distance can be predefined and stored in the ultrasonic sensor system. Furthermore, this distance corresponds to the difference between a first distance of a first ultrasonic sensor relative to the vehicle's longitudinal axis and a second distance of a second ultrasonic sensor relative to the vehicle's longitudinal axis.
[0032] When detecting lateral objects using, for example, three or more ultrasonic sensors, the correlation between the sensor spacing perpendicular to the longitudinal axis and the difference in the measured distance to the object can also provide an indication of height. For tall objects, the horizontal spacing will exactly match the measured distance difference. For short objects, due to the existing vertical detection angle, the measured distance difference will be systematically smaller than the horizontal spacing between the ultrasonic sensors.
[0033] According to another configuration of the present invention, the ultrasonic sensor system is configured to determine the positioning of an object relative to the first ultrasonic sensor and the second ultrasonic sensor based on the first ultrasonic echo signal and the second ultrasonic echo signal, and determine a third angle between the first main detection direction and the first detection direction and a fourth angle between the second main detection direction and the second detection direction based on the positioning of the object, respectively, and adjust the first ultrasonic echo signal based on the third angle and adjust the second ultrasonic echo signal based on the fourth angle.
[0034] Advantageously, by adjusting the ultrasonic echo signals according to the corresponding angle between the main detection direction and the detection direction, inhomogeneities in the detection behavior of the respective ultrasonic sensors can be corrected. This makes it possible, for example, to meaningfully compare the ultrasonic echo signals for further analysis, such as for object height classification. For example, adjustments can be made to the amplitude level, reflectivity, or correlation, as these are sensor characteristics that are correlated between the main detection direction and the detection direction. In particular, the ultrasonic sensor system can also be configured to evaluate the ultrasonic echo signals of two ultrasonic sensors using a machine learning model to determine an object height classification.
[0035] Positioning is generally understood to mean an assignment to a specific spatial location, in this case the ultrasonic sensor relative to an object.
[0036] The third and fourth angles are again to be understood as lying in a horizontal plane relative to the vehicle.
[0037] In this case, a detection direction is to be understood as meaning the direction formed by the axial connection between the ultrasonic sensor and the object.
[0038] According to another embodiment of the present invention, the ultrasonic sensor system is designed to adjust the first ultrasonic echo signal and the second ultrasonic echo signal according to respective amplitude levels, and to determine height information of the object based on a comparison of the adjusted first ultrasonic echo signal with the adjusted second ultrasonic echo signal.
[0039] Advantageously, it is possible to determine whether an object is high or low. For example, in a parking situation, this information can be used to determine whether the object can be driven over by the vehicle without causing damage to the vehicle.
[0040] Here, for each ultrasonic echo signal, in order to compensate for the difference between the detection direction and the main detection direction, the amplitude loss caused by the viewing angle can be added to the "original" ultrasonic echo signal so that the ultrasonic echo signals can be compared with each other. Accordingly, the amplitude level is increased according to the angle.
[0041] According to a further embodiment of the invention, the ultrasonic sensor system is designed to adjust the corresponding amplitude levels as a function of the values respectively predefined for the third angle and the fourth angle.
[0042] An advantage here is that this is a simple possibility for adjusting the amplitude level.
[0043] Thus, for example, based on a previous test series, corresponding predefined values can be associated with the corresponding angles and stored in a lookup table for retrieval.
[0044] According to another embodiment of the present invention, the ultrasonic sensor system is configured to classify the object as high if the adjusted first ultrasonic echo signal and the adjusted second ultrasonic echo signal deviate from each other by less than a predetermined threshold value, and / or to classify the object as low if the adjusted first ultrasonic echo signal is greater than the adjusted second ultrasonic echo signal by at least a predetermined threshold value.
[0045] An advantage here is that this is a simple possibility for determining whether an object should be classified as high or low.
[0046] This is especially because, due to the smaller vertical viewing angle of the inner ultrasonic sensor compared to the outer ultrasonic sensor, the amplitude of the inner ultrasonic sensor is higher than that of the outer ultrasonic sensor for low objects after adjustment.
[0047] The present invention further relates to a vehicle, in particular a passenger car, having an ultrasonic sensor system according to the invention. A first ultrasonic sensor and a second ultrasonic sensor are arranged on the vehicle such that a first main detection direction of the first ultrasonic sensor encloses a first angle with respect to the longitudinal axis, and a second main detection direction of the second ultrasonic sensor encloses a second angle with respect to the longitudinal axis, wherein the first angle is smaller than the second angle. BRIEF DESCRIPTION OF THE DRAWINGS
[0048] Figure 1 A vehicle configured according to the invention is schematically shown in a top view using one specific embodiment of an ultrasonic sensor system according to the invention for detecting objects in the surroundings of the vehicle. DETAILED DESCRIPTION
[0049] Figure 1 A vehicle configured according to the invention is schematically shown in a top view using one specific embodiment of an ultrasonic sensor system according to the invention for detecting objects in the surroundings of the vehicle.
[0050] A schematic top view shows a detail of a vehicle 100 configured according to the invention, for example a passenger vehicle, which is equipped with an embodiment of an ultrasonic sensor system 100 according to the invention. Ultrasonic sensor system 100 has at least one first ultrasonic sensor 20 for emitting a first ultrasonic signal and receiving a first ultrasonic echo signal, and a second ultrasonic sensor 30 for emitting a second ultrasonic signal and receiving a second ultrasonic echo signal.
[0051] The processing unit 40 of the ultrasonic sensor system 10 is connected to the first ultrasonic sensor 20 and the second ultrasonic sensor 30 via one or more lines. The processing unit 40 can be configured accordingly and can include components that enable operation of the first ultrasonic sensor 20 and the second ultrasonic sensor 30 and, in addition, enable evaluation of the first and second ultrasonic echo signals received by the first ultrasonic sensor 20 and the second ultrasonic sensor 30. For this purpose, corresponding components for storing, processing, and evaluating the received signals can be provided (not shown in detail here). In this way, the processing unit 40 can control the operation and / or interrogation status of the first ultrasonic sensor 20 and the second ultrasonic sensor 30, or receive or actively retrieve corresponding data or signals from the first ultrasonic sensor 20 and the second ultrasonic sensor 30.
[0052] Furthermore, ultrasonic sensor system 10 is arranged on vehicle 100 such that the environment of vehicle 100 can be monitored using ultrasonic sensor system 10. For this purpose, for example, first ultrasonic sensor 20 and second ultrasonic sensor 30 are mounted on a bumper or other body component of vehicle 100. In particular, first ultrasonic sensor 20 and second ultrasonic sensor 30 are mounted on vehicle 100 such that a first main detection direction 21 of the first ultrasonic sensor encloses a first angle 22 with respect to a longitudinal axis 101 of vehicle 100, and a second main detection direction 31 of the second ultrasonic sensor 30 encloses a second angle 32 with respect to longitudinal axis 101, wherein first angle 22 is smaller than second angle 32. In particular, first ultrasonic sensor 30 and second ultrasonic sensor 30 are also mounted on vehicle 100 such that they are arranged on a common side of longitudinal axis 101 of vehicle 100.
[0053] Ultrasonic sensor system 10, and in particular processing unit 40, is configured to select a first amplitude threshold value for a first ultrasonic echo signal of first ultrasonic sensor 20 that is smaller than a second amplitude threshold value for a second ultrasonic echo signal of second ultrasonic sensor 30, whereby the detection ranges of first ultrasonic sensor 20 and second ultrasonic sensor 30 are correspondingly different, wherein the detection ranges are indicated by a thin dashed boundary with a curved connecting line.
[0054] Furthermore, ultrasonic sensor system 10 , and in particular processing unit 40 , may be configured to filter the first ultrasonic echo signal received by means of first ultrasonic sensor 20 , in particular by means of a Kalman filter and / or by means of a Ransac algorithm.
[0055] In an alternative embodiment (not shown in the figures), ultrasonic sensor system 10 can be configured to lower the first and / or second amplitude threshold values compared to the normal mode of the respective ultrasonic sensors 20, 30. If this is performed for both ultrasonic sensors 20 and 30, both detection ranges are accordingly widened. In this case, it is also useful to filter the second ultrasonic echo signal.
[0056] In addition, the first ultrasonic sensor 20 and the second ultrasonic sensor 30 can be installed on the vehicle 100 so that the first ultrasonic sensor 20 has a first distance x1 and the second ultrasonic sensor 30 has a second distance x2 from the longitudinal axis 101 of the vehicle 100, wherein the first distance x1 is smaller than the second distance x2.
[0057] Additionally or alternatively, the ultrasonic sensor system 10 can be configured to determine a first distance d1 between the first ultrasonic sensor 20 and the object 110 and a second distance d2 between the second ultrasonic sensor 30 and the object 110, and to compare the difference between the first distance d1 and the second distance d2 with a distance d3 between the first ultrasonic sensor 20 and the second ultrasonic sensor 30, which is located perpendicular to the longitudinal axis of the vehicle.
[0058] In addition, the ultrasonic sensor system 10 can be configured to determine the position of the object 110 relative to the first ultrasonic sensor 20 and the second ultrasonic sensor 30 based on the first ultrasonic echo signal and the second ultrasonic echo signal, and to determine a third angle 23 between the first main detection direction 21 and the first detection direction 24 and a fourth angle 33 between the second main detection direction 31 and the second detection direction 34 based on the positioning of the object 110, respectively, and to adjust the first ultrasonic echo signal based on the third angle 23 and the second ultrasonic echo signal based on the fourth angle 33.
[0059] In particular, ultrasonic sensor system 10 can be configured to adjust the first ultrasonic echo signal and the second ultrasonic echo signal relative to respective amplitude levels and to determine height information about object 110 based on a comparison of the adjusted first ultrasonic echo signal with the adjusted second ultrasonic echo signal. Ultrasonic sensor system 10 can be configured to adjust the respective amplitude levels based on values predefined for third angle 23 and fourth angle 33, respectively.
[0060] In particular, the ultrasonic sensor system 10 can be configured to classify the object 110 as high if the adjusted first ultrasonic echo signal and the adjusted second ultrasonic echo signal deviate from each other by less than a predetermined threshold value, and / or to classify the object 110 as low if the adjusted first ultrasonic echo signal is greater than the adjusted second ultrasonic echo signal by at least a predetermined threshold value.
Claims
1. An ultrasonic sensor system (10) for detecting at least one object (110) in the environment of a vehicle (100), wherein: The ultrasonic sensor system (10) has at least one first ultrasonic sensor (20) for emitting a first ultrasonic signal and receiving a first ultrasonic echo signal, and a second ultrasonic sensor (30) for emitting a second ultrasonic signal and receiving a second ultrasonic echo signal, wherein the first ultrasonic sensor (20) and the second ultrasonic sensor (30) can be mounted on the vehicle (100) in such a way that a first main detection direction (21) of the first ultrasonic sensor encloses a first angle (22) relative to a longitudinal axis (101) of the vehicle (100), and a second main detection direction (31) of the second ultrasonic sensor (30) encloses a second angle (32) relative to the longitudinal axis (101), wherein the first angle (22) is smaller than the second angle (32), and wherein the ultrasonic sensor system (10) is configured to select a first amplitude threshold value of the first ultrasonic sensor (20) for the first ultrasonic echo signal to be smaller than a second amplitude threshold value of the second ultrasonic sensor (30) for the second ultrasonic echo signal, or to reduce the first amplitude threshold value and / or the second amplitude threshold value relative to a normal mode.
2. The ultrasonic sensor system (10) according to claim 1, characterized in that The ultrasonic sensor system (10) is designed to filter a first ultrasonic echo signal received by means of the first ultrasonic sensor (20), in particular by means of a Kalman filter and / or by means of a Ransack algorithm.
3. The ultrasonic sensor system (10) according to claim 1, characterized in that The first ultrasonic sensor (20) and the second ultrasonic sensor (30) can be mounted on the vehicle (100) such that the first ultrasonic sensor (20) has a first spacing (x1) from a longitudinal axis (101) of the vehicle (100), and the second ultrasonic sensor (30) has a second spacing (x2) from the longitudinal axis (101) of the vehicle (100), wherein the first spacing (x1) is smaller than the second spacing (x2).
4. The ultrasonic sensor system (10) according to claim 3, characterized in that The ultrasonic sensor system (10) is configured to determine a first distance (d1) between the first ultrasonic sensor (20) and the object (110) and a second distance (d2) between the second ultrasonic sensor (30) and the object (110), and to compare the difference between the first distance (d1) and the second distance (d2) with a distance (d3) between the first ultrasonic sensor (20) and the second ultrasonic sensor (30) perpendicular to the longitudinal axis of the vehicle.
5. The ultrasonic sensor system (10) according to claim 3 or 4, characterized in that The ultrasonic sensor system (10) is configured to determine the position of the object (110) relative to the first ultrasonic sensor (20) and the second ultrasonic sensor (30) based on the first ultrasonic echo signal and the second ultrasonic echo signal, and to determine a third angle (23) between the first main detection direction (21) and the first detection direction (24) and a fourth angle (33) between the second main detection direction (31) and the second detection direction (34) based on the position of the object (110), and to adjust the first ultrasonic echo signal based on the third angle (23) and the second ultrasonic echo signal based on the fourth angle (33).
6. The ultrasonic sensor system (10) according to claim 5, characterized in that The ultrasonic sensor system (10) is configured to adjust the first ultrasonic echo signal and the second ultrasonic echo signal according to respective amplitude levels, and to determine height information of the object (110) based on a comparison of the adjusted first ultrasonic echo signal and the adjusted second ultrasonic echo signal.
7. The ultrasonic sensor system (10) according to claim 6, characterized in that The ultrasonic sensor system (10) is designed to adjust the corresponding amplitude levels as a function of values respectively specified for the third angle (23) and the fourth angle (33).
8. The ultrasonic sensor system (10) according to claim 6 or 7, characterized in that The ultrasonic sensor system (10) is configured to classify the object (110) as high if a modified first ultrasonic echo signal and a modified second ultrasonic echo signal deviate from one another by less than a predetermined threshold value, and / or to classify the object (110) as low if the modified first ultrasonic echo signal is greater than the modified second ultrasonic echo signal by at least a predetermined threshold value.
9. A vehicle (100) having an ultrasonic sensor system (10) according to any one of the preceding claims, wherein: The first ultrasonic sensor (20) and the second ultrasonic sensor (30) are arranged on the vehicle (100) such that a first main detection direction (21) of the first ultrasonic sensor (20) encloses a first angle (22) relative to the longitudinal axis (101), and a second main detection direction (31) of the second ultrasonic sensor (30) encloses a second angle (32) relative to the longitudinal axis (101), wherein the first angle (22) is smaller than the second angle (32).