Ultrasonic sensor unit for a vehicle

Abstract

The present invention relates to an ultrasonic sensor unit for a vehicle, comprising a first ultrasonic sensor element, wherein the ultrasonic sensor unit is configured to emit and / or receive at least one ultrasonic wave by means of the first ultrasonic sensor element, wherein the ultrasonic sensor unit is configured to determine an emission time of the ultrasonic wave and an input time of the reflected ultrasonic wave, wherein the ultrasonic sensor unit is configured to determine a first geometry, in particular a first ellipse, based on the emission time and the input time.

Description

Prior ArtThe present invention relates to an ultrasonic sensor unit for a vehicle and to a vehicle.At present, there are a large number of different solutions for detecting and measuring the distance of objects in the vehicle area by means of ultrasonic sensors. As the number of ultrasonic sensors in the vehicle sector increases and the increased detection requirements continuously increase the need for innovative and robust ultrasonic sensor units.The steady weight reduction in the vehicle sector for reducing consumption and the increasing competition provides cost pressure, so that more favorable and more efficient components for vehicles are demanded more strongly.Disclosure of the InventionThe ultrasonic sensor unit according to the invention for a vehicle having the features of claim 1 has the advantage over the known ones that a successful distance measurement or position determination can take place even in the case of a small movement of the vehicle. Another advantage is that a type of object can be determined. Further preferably, a movement of the vehicle can be compensated by means of the ultrasonic measurement of the ultrasonic sensor unit, in order to thus be able to further increase the detection accuracy. One advantage may be that the previous limitations of ultrasonic sensors can be overcome by providing a trilateration algorithm that operates at higher speeds (up to 15 km / h), longer distances (up to 5 meters), at each steering, as well as for diagonal line and side objects.This is achieved according to the invention in that the ultrasonic sensor unit for a vehicle has a first ultrasonic element, wherein the ultrasonic sensor unit is configured to emit and / or receive at least one ultrasonic wave by means of the first ultrasonic sensor element, wherein the ultrasonic sensor unit is configured to determine a emission time point of the ultrasonic wave and an input time point of the reflected ultrasonic wave, wherein the ultrasonic sensor unit is configured to determine a first geometry, in particular a first ellipse, based on the emission time point with the input time point.In other words, with the aid of the transmission and reception of an ultrasonic signal which has been reflected on an object, a geometry, in particular an ellipse or a semicircle, can be determined on the basis of the propagation time of the respective ultrasonic signal which is composed of the transmission time and the input time. Preferably, a movement travel of the ultrasonic sensor unit between the entry time and the emission time can be determined. Thus, based on the travel time and the movement of the ultrasonic sensor unit, the first geometry, in particular the first ellipse, can be determined.The ultrasonic sensor unit can preferably emit a signal that reaches a punctiform object during the time t 1. Due to the movement of the vehicle, the reflection of the signal reaches the ultrasound unit at time t 2. The movement of the ultrasonic sensor unit can be determined for the time period t1+t2.More preferably, the movement of a second ultrasound element can be determined for the time period t1+t3, wherein t3is the duration of the signal between the reflection at the punctiform object and the arrival of the signal at the second ultrasound element.Thus, the following propagation times can be determined by means of the ultrasonic sensor unit and these can be converted into distances based on the propagation speed of the signal: (t1+t2)→direct echo and (t1+t3) cross echo.Based on the travel times and distances, two rotated ellipses may be determined. For the determination of the ellipse of the direct echo, the distance based on t1+t2 as well as the running speed of the signal can be used. For the determination of the ellipse of the cross echo, the distance based on t1+t3 and the running speed of the signal can be used.The position of the punctiform object is preferably determined by the points of intersection of these two rotated ellipses. By means of the ultrasonic sensor unit, it is possible to use a correlation between the steering angles of the front and rear bumper rods of the vehicle, the speed of the vehicle and / or the measured travel time in order to put the ellipses in a context.It is thus possible to check whether the vehicle is in motion, so that ellipses can be assumed. The type of object can be determined based on the configuration of the ellipses. A punctiform object can preferably be present if there is an intersection point of two or three ellipses (with tolerance). Preferably, a linear object can be present if a common tangent of three ellipses (with tolerance) is present.The dependent claims show preferred developments of the invention.Further preferably, the ultrasonic sensor unit has a second ultrasonic sensor element, wherein the second ultrasonic element is configured to receive the reflected ultrasonic wave, wherein the ultrasonic sensor unit is configured to determine a second geometry, in particular a second ellipse, based on the reception of the reflected ultrasonic wave by means of the second ultrasonic element.An advantage of this embodiment is that a position of an object at which the ultrasonic wave has been reflected can be determined. For this purpose, the time can preferably be determined between the transmission time at the ultrasonic sensor unit and the reception of the reflected ultrasonic wave at the second ultrasonic element. Preferably, a ratio between the propagation time of the ultrasonic wave between the transmission time and the input time at the first ultrasonic element and a transmission time and an input time at the second ultrasonic element can be determined in order to be able to determine the position of the reflected object. Preferably, a second geometry, such as a second ellipse, can be determined in particular on the basis of the propagation time between the transmission time and the reception of the reflected ultrasonic wave at the second ultrasonic element.The ultrasonic sensor unit is preferably configured to determine a position of a point based on the intersection point of the first geometry and the second geometry.An advantage of this embodiment is that an intersection point between the two geometries can be determined by the determination of the respective geometry, in order thus to put the positions of the first ultrasound element and of the second ultrasound element into a context both at the transmission time and at the input time, in particular at the determined point.Preferably, the ultrasonic sensor unit is configured to determine a distance between the point and the ultrasonic sensor unit.An advantage of this embodiment is that, based on the distance between the ultrasonic sensor unit over time, an approach or removal to the point can be determined.Further preferably, the ultrasonic sensor unit is configured to detect a contour of an object by determining a plurality of diagonals.An advantage of this embodiment is that a contour of the object can be determined by a repeated measurement in order thus to be able to distinguish between a punctiform object and a linear object in particular.Further preferably, the ultrasonic sensor unit is configured to determine a type of the object based on the contour.An advantage of this embodiment is that conclusions can be drawn about an object on the basis of the determined contour, such as a pile or a car or the like.Further preferably, the ultrasonic sensor unit is configured to receive and / or determine a movement parameter of the ultrasonic sensor unit, wherein the ultrasonic sensor unit is configured to adapt the first geometry based on the movement parameter.An advantage of this embodiment is that in case the ultrasonic sensor unit moves between the transmission time and the input time of the reflected ultrasonic wave, the movement can be set in a spatial context based on the movement parameter.Further preferably, the ultrasonic sensor unit is configured to adapt the second geometry based on the movement parameter.An advantage of this embodiment is that the accuracy of the determination of the first geometry and of the second geometry can be improved, since the positions of the ultrasonic sensor units can change significantly, in particular during a cornering movement of the vehicle or the like.Further preferably, the movement parameter has at least one speed of a vehicle to which the ultrasonic sensor unit is connected.An advantage of this embodiment is that the change per time step can be taken into account in order to be able to increase the detection accuracy.A further aspect of the invention relates to a vehicle which has an ultrasonic sensor unit as described above and below.Brief Description of the DrawingsHereinafter, embodiments of the invention will be described in detail with reference to the accompanying drawings. In the drawing, the following is: FIG. 1 shows an ultrasonic sensor unit according to an embodiment, FIG. 2 shows a diagram for illustrating the mode of operation of the ultrasonic sensor unit according to one embodiment, FIG. 3 shows a vehicle according to an embodiment, FIG. 4 shows an ultrasonic sensor unit according to an embodiment.Embodiments of the InventionAll the same elements, units and / or steps in all the figures are preferably provided with the same reference numerals.FIG. 1 shows an ultrasonic sensor unit 10 according to an embodiment. The ultrasonic sensor unit 10 for a vehicle 100 has a first ultrasonic sensor element 12, wherein the ultrasonic sensor unit 10 is configured to emit and / or receive at least one ultrasonic wave by means of the first ultrasonic sensor element 12, wherein the ultrasonic sensor unit 10 is configured to determine a emission time point of the ultrasonic wave and an input time point of the reflected ultrasonic wave, wherein the ultrasonic sensor unit 10 is configured to determine a first geometry, in particular a first ellipse, based on the emission time point and the input time point. The ultrasonic sensor unit 10 preferably has a second ultrasonic sensor element 20. As can be seen in FIG. 1, the first ultrasound element 12 moves along the vector 52, such that the signal 56 is emitted from a first location, reflected by an object 50, and the reflected signal 58 is received at a second location by the first ultrasound element 12. Further preferably, the signal 56 is also reflected at the object 50 and received as a reflected signal 60 at a third location by means of the second ultrasound element 20 which moves along a second vector 54.FIG. 2 shows a diagram 200 for illustrating the functioning of the ultrasonic sensor unit 10 according to one embodiment. A first axis 202 and a second axis 204 are shown in the diagram 200. Preferably, a first curve 206, a second curve 208 and a third curve 210 can be represented in diagram 200, which are reflected at an object 212. Based on the curves 206, 208 and 210, intersection points between the curves can be determined based on the curves, which intersection points can form the base points for the first ellipse or first geometry or second geometry.FIG. 3 shows a vehicle 100 according to an embodiment. The vehicle 100 preferably has an ultrasonic sensor unit 10.FIG. 4 shows an ultrasonic sensor unit 10 according to an embodiment. The ultrasonic sensor unit 10 has a first ultrasonic element 12 and a second ultrasonic element 20.

Claims

Ultrasonic sensor unit (10) for a vehicle (100), having a first ultrasonic sensor element (12), wherein the ultrasonic sensor unit (10) is configured to emit and / or receive at least one ultrasonic wave by means of the first ultrasonic sensor element (12), wherein the ultrasonic sensor unit (10) is configured to determine a emission time point of the ultrasonic wave and an input time point of the reflected ultrasonic wave, wherein the ultrasonic sensor unit (10) is configured to determine a first geometry, in particular a first ellipse, based on the emission time point and the input time point.Ultrasonic sensor unit (10) according to claim 1, wherein the ultrasonic sensor unit (10) comprises a second ultrasonic sensor element (20), wherein the second ultrasonic element (20) is configured to receive the reflected ultrasonic wave, wherein the ultrasonic sensor unit (10) is configured to determine a second geometry, in particular a second ellipse, based on the reception of the reflected ultrasonic wave by means of the second ultrasonic element (20).The ultrasonic sensor unit (10) according to claim 2, wherein the ultrasonic sensor unit (10) is configured to determine a position of a point based on an intersection of the first geometry and the second geometry.The ultrasonic sensor unit (10) according to claim 3, wherein the ultrasonic sensor unit (10) is configured to determine a distance between the point and the ultrasonic sensor unit (10).Ultrasonic sensor unit (10) according to one of Claims 2 to 4, wherein the ultrasonic sensor unit (10) is configured to record a contour of an object by a determination of a multiplicity of diagonals.The ultrasonic sensor unit (10) according to claim 5, wherein the ultrasonic sensor unit (10) is configured to determine a type of the object based on the contour.Ultrasonic sensor unit (10) according to one of the preceding claims, wherein the ultrasonic sensor unit (10) is configured to receive and / or determine a movement parameter of the ultrasonic sensor unit (10), wherein the ultrasonic sensor unit (10) is configured to adapt the first geometry based on the movement parameter.The ultrasonic sensor unit (10) according to claims 7 and 2, wherein the ultrasonic sensor unit (10) is configured to adjust the second geometry based on the motion parameter.The ultrasonic sensor unit (10) of claim 8, wherein the motion parameter comprises at least a velocity of a vehicle (100) to which the ultrasonic sensor unit (10) is connected.Vehicle (100) comprising an ultrasonic sensor unit (10) according to one of the preceding claims.

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