Ultrasonic sensor operation for direct measurement of a relative speed

Abstract

The invention relates to a method of ultrasonic sensor operation, the method comprising: - controlling at least one ultrasonic sensor (104) to transmit at least two ultrasonic pulses (202, 204) during a measurement cycle, there being a time interval between the ultrasonic pulses (202, 204) and the measurement cycle being performed in cyclically repeating fashion; - receiving echoes (206, 208, 506, 508, 510, 512, 514, 706, 708, 710, 712, 714, 906, 908, 910, 912, 914) resulting from the ultrasonic pulses, the echoes being caused by an object (106, 108, 110, 402, 404, 406, 602, 604, 606, 802, 804, 806); - determining a relative speed of the ultrasonic sensor (104) vis-à-vis the object on the basis of the temporal position of the ultrasonic pulses (202, 204) with respect to one another and their echoes (206, 208, 506, 508, 510, 512, 514, 706, 708, 710, 712, 714, 906, 908, 910, 912, 914) with respect to one another within the measurement cycle.

Description

ULTRASONIC SENSOR OPERATION FOR DIRECT MEASUREMENT OF RELATIVE SPEED FIELD OF TECHNOLOGY

[0001] The invention relates to a method for ultrasonic sensor operation, a computer program product and ultrasonic sensors for directly measuring the relative speed of one or more objects in the environment of one or more ultrasonic sensors. STATE OF THE ART

[0002] Currently, most vehicles, and probably all autonomous vehicles, are equipped with ultrasonic sensors. Near-field perception systems based on ultrasonic sensors determine the distance to obstacles based on the time of flight of echo reflections and combine this 1-dimensional information into 2D / 3D environment maps using 2D or 3D trilateration. These maps are updated with each measurement cycle or after the application of algorithms.

[0003] In the prior art, US 9 297 891 B2 discloses an ultrasonic measuring device for a vehicle, wherein an ultrasonic signal is received that was previously emitted by an internal or external ultrasonic transmitter, wherein the received ultrasonic signal exhibits a temporal change in the period lengths. By comparing it with a reference signal, a relative speed between the ultrasonic measuring device and an object reflecting the signal can be determined, for example.

[0004] It is an object of the invention to provide an improved method, an improved computer program product, and improved ultrasonic sensors for measuring relative velocity using ultrasonic sensor data. The objects underlying the invention are achieved by the features of the independent claims. SUMMARY

[0005] In one aspect, a method of ultrasonic sensor operation is disclosed, comprising: -Controlling at least one ultrasonic sensor to emit at least two ultrasonic pulses during a measuring cycle, with a time interval between the ultrasonic pulses, the measuring cycle being carried out cyclically; -Receiving echoes resulting from the ultrasonic pulses, the echoes being caused by an object; -Determining a relative speed of the ultrasonic sensor to the object based on the temporal position of the ultrasonic pulses to each other and their echoes to each other within the measuring cycle.

[0006] In a further aspect, a computer program product, in particular a computer-readable storage medium, is disclosed, wherein the computer program product comprises computer-executable code, wherein the code is executable by at least one processor of a computer device to cause the computer device to carry out the method described above.

[0007] In a further aspect, an ultrasonic sensor, in particular for use in a vehicle, is disclosed, wherein the ultrasonic sensor is designed to carry out the method described above.

[0008] The method according to the invention, the computer program product according to the invention, and the ultrasonic sensor according to the invention could enable a rapid and resource-efficient determination of the relative speed of an object reflecting the ultrasonic pulses by means of at least two—in some examples identical—ultrasound pulses emitted in the same measurement cycle. No frequency or amplitude modulation of the emitted signal is necessary to enable the determination of the relative speed. Furthermore, no resource-intensive comparison or calculation operations need to be performed. A comparison of distance information between the measurement cycles in order to determine a relative speed is also eliminated, since the relative speed can be determined within just one measurement cycle.The method according to the invention, the computer program product according to the invention and the ultrasonic sensor according to the invention can thus be provided as a simple software or hardware solution. This could have the advantage of providing cost-effective inventive methods, computer program products and ultrasonic sensors that enable a quick and easy measurement of a relative speed of an object within only one measurement cycle.

[0009] In one example, one or more ultrasonic sensors are installed in a vehicle, such as an autonomous vehicle, or any other vehicle. However, the ultrasonic sensors can also be installed in another object or means of transport, such as a truck, a bus, a bicycle, an airplane, or a scooter. These ultrasonic sensors can, for example, cyclically emit ultrasonic pulses and, for example, receive a reflected portion of an ultrasonic pulse. In order for such an emitted ultrasonic pulse to be received again, it is reflected, for example, by an object that is at a certain distance from the ultrasonic sensor and then reflected back to the emitting ultrasonic sensor.In another example, the ultrasonic pulse can also be reflected back to an ultrasonic sensor other than the transmitting ultrasonic sensor and received there as an echo. In one example, the distance to the object that reflected the ultrasonic pulse can be determined from the propagation time of the ultrasonic pulse from the transmission to the reception of the echo. The portion of the ultrasonic pulse that is reflected by the object and received again by an ultrasonic sensor can generally be referred to as an echo or reflection.

[0010] In one example, a measuring cycle comprises the entire duration from the transmission of the ultrasonic pulses to the reception of the echoes of the ultrasonic pulses, for example, from the transmission of the first ultrasonic pulse to the reception of the last echo of the last transmitted ultrasonic pulse. The measuring cycle has a defined duration, which can be 50 ms, for example. However, other time periods for the duration of the measuring cycle are also conceivable, such as 25 ms, 75 ms, 100 ms, or 500 ms, or any values ​​in between. For example, the duration of the measuring cycle determines the maximum distance an object can be from the ultrasonic sensor. If the measuring cycle is too short, the echo caused by the distant object may no longer be received within the time of the measuring cycle.One of the determining factors is the propagation speed of the ultrasonic pulse, which in air, for example, is approximately 330 m / s. With a measurement cycle duration of 50 ms, this can be achieved directly at the beginning of the measurement cycle. If an ultrasonic pulse is emitted, it will travel a distance of 16.5 m through the air at 330 m / s within 50 ms. Thus, with a measurement cycle duration of 50 ms, only objects that are a maximum of 8.25 m or less away from the ultrasonic sensor (which transmits and receives the signal) will be detected, as the ultrasonic pulse can travel a distance of 8.25 m to the object within 50 ms, and the echo of the ultrasonic pulse can travel a distance of 8.25 m from the reflecting object back to the ultrasonic sensor. For a measurement cycle duration of 100 ms, for example, the maximum distance doubles to 16.5 m.

[0011] According to the invention, several ultrasonic pulses are transmitted and received per measuring cycle, for example at least two ultrasonic pulses per measuring cycle. This example also includes any other number of ultrasonic pulses, for example three, four or more ultrasonic pulses. In another example, the ultrasonic pulses are all transmitted one after the other at the beginning of the measuring cycle to allow sufficient time to receive any echoes to the transmitted ultrasonic pulses. The beginning of the measuring cycle can, for example, comprise the first 20%, with values ​​between 5% and 50% being conceivable here. According to the invention, there is a time interval between the ultrasonic pulses, which is defined as the time interval from the beginning of a first ultrasonic pulse to the beginning of a subsequent ultrasonic pulse.Each of the multiple transmitted ultrasonic pulses can then be reflected by an object and received again as an echo, with the temporal position of the received echoes defining a temporal echo spacing. The temporal echo spacing, or the temporal position of the received echoes, is the temporal separation of the amplitude maxima of each echo. One prerequisite for receiving echoes is, for example, that the object is not too far from the ultrasonic sensor.

[0012] In one example, an object that reflects the multiple emitted ultrasonic pulses may have a relative speed with respect to the ultrasonic sensor. The ultrasonic sensor may, for example, be installed in a vehicle that moves at a speed in one direction (vl). In one example, the object may also move at a speed in the same direction (v2). For example, a relative speed of the object with respect to the ultrasonic sensor means that the distance of the ultrasonic sensor, which is, for example, installed in a vehicle, from the object decreases or increases over a period of time. If the distance from the ultrasonic sensor to the object decreases over a period of time, this may mean that the relative speed of the object to the ultrasonic sensor can be negative, i.e. can have a negative (-) sign, and that the speed of the object in the direction is less than the speed of the ultrasonic sensor in the direction (v2 is less than vl), whereby both vl and / or v2 can take on negative values.

[0013] If the distance from the ultrasonic sensor to the object increases over a period of time, this can mean that the relative velocity of the object to the ultrasonic sensor can be positive, i.e. it can have a positive (+) sign, and that the velocity of the object in the direction is higher than the velocity of the ultrasonic sensor in the direction (v2 is less than vl), where both vl and / or v2 can take negative values. In one example, the relative velocity can also take the value zero, which can mean that the velocity of the object in the direction is exactly the same as the velocity of the ultrasonic sensor in the direction (v2 is equal to vl), where both vl and v2 can take negative or positive values.This can also be the case if both the speed of the object in the direction and the speed of the ultrasonic sensor in the direction are zero (vl is equal to zero and v2 is equal to zero), i.e. both the ultrasonic sensor and the object are stationary and not moving. In another example, the speed of the ultrasonic sensor in the direction or speed of the object in the direction can be zero (vl is equal to zero or v2 is equal to zero), and the speed of the other in the direction can be greater than zero or less than zero. A speed less than zero or a negative value for the speed vl and / or v2 can mean that the object and / or the ultrasonic sensor is moving in the opposite direction to the other of the two.

[0014] In one example, the ultrasonic sensor is moving at a different speed in the direction than the object (vl is not equal to v2), where vl and v2 can be a rational number (including zero). This can mean that the relative speed of the object with respect to the ultrasonic sensor can take on a numerical value from the set of rational numbers excluding zero. In one example, the time interval between the emitted ultrasonic pulses is not equal to the time interval between echoes, which can mean that the relative speed is a rational number other than zero.

[0015] In one example, the method can determine the value of the relative speed of the ultrasonic sensor to the object from the temporal distance or the temporal echo distance, i.e. from the temporal position of the emitted ultrasonic pulses to each other or the temporal position of the echoes to each other. In another example, the Ultrasonic sensor with the same speed in the direction of the object (vl is equal to v2), where vl and v2 can be a rational number (including zero). In this example, too, the method can determine the value of the relative speed of the ultrasonic sensor to the object from the temporal distance or the temporal echo distance, i.e. from the temporal position of the emitted ultrasonic pulses relative to one another or the temporal position of the echoes relative to one another, which in this case would be zero. The described procedures could have the advantage that the relative speed of the object relative to the ultrasonic sensor can be determined within just a single measuring cycle. For example, there is no need to wait until the position of the object relative to the ultrasonic sensor is updated from measuring cycle to measuring cycle in order to determine a relative speed.This results in a faster determination of the relative velocity compared to a method in which the relative velocity can only be determined by comparing different measurement cycles. Furthermore, the described procedures could have the advantage that no complex computational operations and / or signal modulation are required to determine a relative velocity.

[0016] For example, the method comprises determining a spatial position of the object relative to the ultrasonic sensor based on at least one of the two ultrasonic pulses and the echo associated with the respective ultrasonic pulse. Thus, the method can be used, for example, in parallel with determining the relative speed to determine the distance between the object and the ultrasonic sensor. In one example, if the ultrasonic sensor is used in a vehicle, this distance information can be used, for example, by a parking aid, during an automated parking process, or to determine the distance to vehicles driving ahead or behind the vehicle, for example, during an autonomous driving process. This could have the advantage that the use of additional sensors to determine the distance is not necessary, thus saving costs and computing operations.

[0017] For example, the method comprises analytically determining the relative velocity, where -the temporal position of the ultrasonic pulses relative to each other comprises their temporal pulse spacing and the temporal position of the echoes relative to each other comprises a temporal echo spacing of the echoes relative to each other, whereby the relative speed is determined on the basis of the temporal pulse spacing and the temporal echo spacing or -the spatial position comprises a distance, wherein the relative speed is determined using a difference between the distances determined on the basis of the two ultrasonic pulses and the at least one time interval.

[0018] In one example, the object is moving faster in the same direction relative to the ultrasonic sensor. Here, the temporal echo separation, i.e., the temporal position of the received echoes relative to each other, would be greater than the temporal separation of the ultrasonic pulses, i.e., the temporal position of the emitted ultrasonic pulses relative to each other. This is due to the fact that the object, relative to the ultrasonic sensor, has moved further away from the ultrasonic sensor at the time the second ultrasonic pulse is emitted than it was at the time the first ultrasonic pulse was emitted. Here, the relative speed can be determined analytically based on the times the ultrasonic pulses are emitted and the times the echoes of the ultrasonic pulses are received. In this case, the analytical determination is carried out using the formula v reiativ= 330 — s * 1), where a propagation speed of 330 m / s is used for the Ultrasonic pulses are assumed. In another example, other propagation velocities for the ultrasonic pulses are also conceivable, e.g., depending on the ambient temperature.

[0019] In one example, the object moves more slowly relative to the ultrasonic sensor in the same direction. Here, the temporal echo spacing, i.e., the temporal position of the received echoes relative to each other, would be smaller than the temporal spacing of the ultrasonic pulses, i.e., the temporal position of the emitted ultrasonic pulses relative to each other. This is due to the fact that the object, relative to the ultrasonic sensor, moved closer to the ultrasonic sensor at the time the second ultrasonic pulse was emitted than it was at the time the first ultrasonic pulse was emitted. Here, the relative speed can be determined analytically based on the times the ultrasonic pulses were emitted and the times the echoes of the ultrasonic pulses were received. In this case, the relative speed assumes a negative value. In one example, the analytical determination is performed using the formula v reiativ = 330 — * where a propagation speed of 330 m / s is assumed for the ultrasonic pulses. In another example, other propagation speeds are also conceivable, e.g., depending on the ambient temperature for the ultrasonic pulses.

[0020] In one example, the object is moving relative to the ultrasonic sensor in the same direction at the same speed. Here, the temporal echo separation, i.e. the temporal position of the received echoes relative to each other, would be equal to the temporal separation of the ultrasonic pulses, i.e. the temporal position of the transmitted ultrasonic pulses relative to each other. This is due to the fact that at the time the second ultrasonic pulse was transmitted, the object relative to the ultrasonic sensor had neither moved further away from the ultrasonic sensor nor further towards the ultrasonic sensor than it had at the time the first ultrasonic pulse was transmitted. This can be the case if the speeds of the ultrasonic sensor and the object have the same value, which can also be zero.Here, the relative velocity can be determined analytically based on the times of transmission of the ultrasonic pulses and the times of reception of the echoes of the ultrasonic pulses, which in this case assumes the value zero. In one example, the analytical determination is carried out using the formula v. rplntiv = 330 — * 1), where a A propagation speed of 330 m / s is assumed for the ultrasonic pulses. In another example, other propagation speeds are also conceivable for the ultrasonic pulses, e.g., depending on the ambient temperature.

[0021] In another example, the spatial position includes the spatial distance of the object relative to the ultrasonic sensor, for example, when transmitting a first ultrasonic pulse (dl) and a second ultrasonic pulse (d2) in the unit of measurement meters (m), whereby other units of measurement are also conceivable, which are converted to the unit of measurement meters before use. In this example, the relative speed is calculated using the . formula

[0022] For example, the relative speed is determined by a machine learning module, where the machine learning module is trained to determine the relative speed of the ultrasonic sensor to the object based on the relative temporal position of the ultrasonic pulses and their relative echoes. If, for example, a previously trained machine learning module is used, it can be further trained and adapted using data acquired during vehicle operation. For example, it is conceivable to use the relative temporal position of the ultrasonic pulses and echoes and the module's own relative speed output as training data.

[0023] For example, each echo is assigned a probability, where the Probability includes that at least one object actually detects the respective echo caused, whereby the relative speed is determined only using echoes whose probability is above a predetermined threshold. For example, multiple received echoes may overlap if multiple objects are at the same distance from the ultrasonic sensor at the time at least one ultrasonic pulse is emitted. In another example, if at least two ultrasonic pulses are emitted, the received echo from, for example, the first ultrasonic pulse may overlap with the time at which a later ultrasonic pulse is emitted. This may be the case, for example, if the object is very close to the ultrasonic sensor. In the examples mentioned, the echoes cannot be assigned to an object with absolute certainty.

[0024] In general, echoes can be assigned a probability with which they belong to an object. Only if this probability lies above a predefined threshold, for example, is the echo then used to determine a relative speed of the object. The probability threshold can, for example, have a value between 10% and 90%, preferably a value between 20% and 80%, and particularly preferably a value between 40% and 60%. For example, the threshold can have a value of 50%. Only if, for example, the probability of the echo belonging to an object lies above this threshold is the echo used to determine a relative speed. The advantage of this approach could be to create a balance between false positives and false negatives for a specific relative speed.

[0025] For example, the probability is influenced by at least one of the following factors: 1.) by a difference in the signal propagation time of the ultrasonic pulses from transmission to reception of the respective echoes, whereby a smaller difference leads to an increased probability; 2.) by a difference in the determined relative speed of the object in the current measurement cycle and in an immediately previous measurement cycle, whereby a smaller difference leads to an increased probability; 3.) by a difference in the amplitudes of the received echoes associated with the object, with a smaller difference leading to an increased probability; 4.) the width of the echo, with a sharper echo leading to a higher probability than a wide echo; 5.) from a shape of a time-amplitude curve of the received echoes associated with the object, with a more similar shape leading to a higher probability; 6.) whether the probability of the echoes in the immediately previous measurement cycle is above a threshold value and the echoes were thus determined to belong to the object, whereby a probability above the threshold value in the immediately previous measurement cycle leads to an increased probability in the current measurement cycle; 7.) further confirmation of the presence of the object at a distance from the ultrasonic sensor corresponding to the signal propagation time using another sensor system, wherein the other sensor system comprises at least one camera and / or at least one radar and / or at least one LIDAR.

[0026] In the example mentioned under 1.), when several ultrasonic pulses are emitted, the signal propagation times from the emission of the respective ultrasonic pulse to the reception of the corresponding echo from an object are compared. The more similar these signal propagation times are for each object, the more likely it is that the echo actually came from the same object. While strongly differing signal propagation times could be caused by a high or very high absolute numerical value of the relative speed, this also increases the probability that one of the echoes could, for example, come from a different object. Thus, more similar signal propagation times also lead to a higher probability that the echoes can be assigned to the same object.

[0027] In the example mentioned under 2.), the relative velocity determined in the immediately preceding measurement cycle is compared with the relative velocity determined in the current measurement cycle. The closer these are to each other, the higher the probability that the echoes from which this relative velocity was determined can be assigned to the object causing it. The assumption in this example is that the relative velocity of an object cannot change significantly between a measurement cycle lasting, say, 50 ms and the next measurement cycle. Should this be the case, the received echoes could also be artifacts, for example.

[0028] In the example mentioned under 3.), a similar amplitude level of the received echoes assigned to the object also leads to a higher probability that the echoes can be assigned to the object, since it can be assumed that with several emitted ultrasound pulses with the same amplitude, a similar or identical amplitude of the echo can also be received.

[0029] In the example mentioned under 4.), a sharper echo reduces the possibility of multiple echoes overlapping. Thus, with a sharper echo, it can be assumed with a higher probability that this echo can be attributed to an object.

[0030] In the example mentioned under 5.), it can be assumed that if several ultrasonic pulses of the same shape are emitted, the echoes received will also have a similar shape. Thus, a similar shape of the received echoes also leads to a higher probability that they can be assigned to a particular object.

[0031] In the example mentioned under 6.), the probability of the echo belonging to the object determined in the immediately preceding measurement cycle is compared with the probability of the echo belonging to the object determined in the current measurement cycle. The higher the probability in the immediately preceding measurement cycle, the higher the probability can also be in the current measurement cycle. This is based on the assumption that within a measurement cycle lasting, say, 50 ms, only minor influences, for example, in the form of artifacts, can affect the echoes and their belonging to the object.

[0032] In the example mentioned under 7.), the echoes' association with the object can also be confirmed by other sensors, which influences the probability. For example, the sensors mentioned under 7., in the form of a camera, radar, and / or UDARS, can be used to increase the probability of assigning the echoes received by the ultrasonic sensor to the object.

[0033] For example, determining the relative speed further comprises: varying, in different measuring cycles, the number of emitted ultrasonic pulses and / or the temporal pulse spacing and / or the temporal pulse duration and / or a duration of the measuring cycle, -wherein when controlling several ultrasonic sensors, the respective ultrasonic sensors emit a different number of ultrasonic pulses and / or use a different pulse spacing and / or use a different pulse duration and / or use a different measurement cycle duration, -wherein preferably the duration of the measuring cycle is varied between 25 ms and 100 ms, and / or the temporal pulse interval is varied between 0.5 ms and 10 ms and / or the temporal pulse duration is varied between 0.5 ms and 5 ms.

[0034] In one example, varying the aforementioned factors can lead to echoes being assigned to an object with a higher probability. For example, when three ultrasonic pulses are emitted per measurement cycle, the received echoes can be assigned to an object with a higher probability than when only two ultrasonic pulses are emitted per measurement cycle. In another example, a longer pulse spacing can lead to the received echoes being assigned to an object with a higher probability. In another example, a shorter pulse duration can lead to the received echoes being assigned to an object with a higher probability. In another example, a longer measurement cycle can lead to the received echoes being assigned to an object with a higher probability.The examples mentioned in this paragraph could have the advantage of increasing the probability of attributing the echoes to an object.

[0035] It is understood that one or more of the above examples may be combined with each other, as long as the examples are not mutually exclusive. BRIEF DESCRIPTION OF THE DRAWINGS

[0036] The following examples are explained in more detail using the drawings. They show:

[0037] Fig. 1 is a diagram of a moving vehicle in which ultrasonic sensors are installed, as well as several objects moving in the same direction at a speed relative to the vehicle;

[0038] Fig. 2 shows a graphical representation of transmitted ultrasound pulses and their received echoes;

[0039] Fig. 3 shows a graphical representation of the amplitudes of received echoes in detail;

[0040] Fig. 4 is another diagram of a moving vehicle incorporating ultrasonic sensors and several objects moving in the same direction at a speed relative to the vehicle;

[0041] Fig. 5 shows another graphical representation of transmitted ultrasound pulses and their received echoes;

[0042] Fig. 6 is another diagram of a moving vehicle incorporating ultrasonic sensors and several objects moving in the same direction at a speed relative to the vehicle;

[0043] Fig. 7 shows another graphical representation of transmitted ultrasound pulses and their received echoes;

[0044] Fig. 8 is another diagram of a moving vehicle incorporating ultrasonic sensors and several objects moving in the same direction at a speed relative to the vehicle;

[0045] Fig. 9 shows another graphical representation of transmitted ultrasound pulses and their received echoes. DETAILED DESCRIPTION

[0046] In the following, similar elements are identified by the same reference numerals.

[0047] Figure 1 shows a vehicle 102 on which several ultrasonic sensors 104 are installed. The vehicle 102 moves at a speed of 3 m / s in direction 112. Furthermore, Figure 1 shows three objects 106, 108, 110, which also move in the same direction 112. Object 106 moves at a speed of 3 m / s, object 108 at a speed of 0 m / s, and object 110 at a speed of 9 m / s.

[0048] The ultrasonic sensors 104 in Figure 1 transmit ultrasonic pulses 114 toward the objects and receive the echoes reflected from the transmitted ultrasonic pulses. For example, only the path 114 of a transmitted ultrasonic pulse toward the object 106 and the path 114 of receiving the corresponding echo are shown. However, it can be assumed that all ultrasonic sensors transmit corresponding ultrasonic pulses toward the objects and receive the corresponding echoes.

[0049] The objects 106, 108, 110 all have the respective speed in the direction 112 described above. In the example of the object 106, which is moving with a speed of 3 For example, if the object is moving at a speed of 1 m / s in direction 112, the relative speed to the vehicle 102 or the emitting ultrasonic sensor 104 is 0 m / s, since the vehicle 102 or the ultrasonic sensor 104 is also moving at 3 m / s in direction 112. The following explains how the relative object speeds are determined based on the emitted ultrasonic pulses and the received echoes.

[0050] Figure 2 shows a graphical representation of the amplitude of two transmitted ultrasonic pulses 202, 204 and the amplitude of the received echoes, here illustratively for the last two echoes 206, 208, which are caused by the reflection of the transmitted ultrasonic pulses 202, 204 from the furthest object 110 back to a received ultrasonic sensor 104. Echo 206 was caused by the reflection of ultrasonic pulse 202 from object 110, and echo 208 was caused by the reflection of ultrasonic pulse 204 from object 110.

[0051] Also shown in Figure 2 is position 210, which represents the distance of object 110 from ultrasonic sensor 104 at the time of transmission of the first ultrasonic pulse 202, as well as position 212, which represents the distance of object 110 from ultrasonic sensor 104 at the time of impact and reflection of the ultrasonic pulse 202 onto object 110. Position 212 corresponds to the echo 206 caused by object 110.

[0052] Figure 3 shows the graphical progression of the amplitudes of echoes 206, 208 in detail. The lower graph 302 shows only the progression of echo 206. The upper graph 304 shows the progression of echo 208 after the progression has been shifted to the left by the distance between the two transmitted ultrasonic pulses 202, 204. In the example in Figures 1, 2, and 3, the latency between the two ultrasonic pulses 202, 204 is exactly 1 ms, measured from the end of the first ultrasonic pulse 202 to the beginning of the second ultrasonic pulse 204. The duration of the two ultrasonic pulses 202, 204 is 2.5 ms each. This results in a time interval between the two ultrasonic pulses 202, 204, i.e. the temporal position of the ultrasonic pulses 202, 204 relative to one another, of 3.5 ms, measured from the beginning of the first ultrasonic pulse 202 to the beginning of the second ultrasonic pulse 204.Again, position 210 shows the distance of object 110 from ultrasonic sensor 104 at the time of transmission of the first ultrasonic pulse 202, and position 212 shows the distance of object 110 from ultrasonic sensor 104 at the time of impact and reflection of ultrasonic pulse 202 onto object 110. Newly shown is position 306 of the distance of object 110 from ultrasonic sensor 104 at the time of impact and reflection of ultrasonic pulse 204 onto object 110.

[0053] In Figure 3, the distance of the object 110 from the ultrasonic sensor 104 at the time of receiving the echo 212 from the first ultrasonic pulse 202 is approximately 4.074 m. Furthermore, the distance of the object 110 from the ultrasonic sensor 104 at the time of receiving the echo 306 from the second ultrasonic pulse 204 is approximately 4.097 m. Thus, from the time of receiving the first echo 212 from the first ultrasonic pulse 202 to receiving the second echo 306 from the second ultrasonic pulse 204, the object 110 has moved away from the emitting ultrasonic sensor 104 by 0.023 m. With a time interval of 3.5 ms between the two ultrasonic pulses, a relative speed of the object 110 to the vehicle 102 or to the ultrasonic sensors 104 of approximately 6 m / s (v reiativ (see Figure 1).

[0054] Figure 4 again shows vehicle 102 moving in direction 112, as well as ultrasonic sensors 104, which emit ultrasonic pulses 114 and receive their echoes. Figure 4 also shows objects 402, 404, and 406 with their corresponding relative velocities in direction 112 (402 = 3 m / s, 404 = 0 m / s, 406 = 9 m / s). Here, too, vehicle 102 has a velocity of 3 m / s in direction 112.

[0055] In Figure 4, the procedure for determining the relative speed of objects 402, 404, and 406 is analogous to the procedure explained in the example in Figure 1-3. However, after a certain time, it can be assumed that objects 402 and 404 overlap, since object 404 is stationary and object 402 is moving at a speed of 3 m / s in direction 112.

[0056] Figure 5 again shows the graphical progression of the amplitude of the two transmitted ultrasonic pulses 202, 204 as well as the amplitude of the received echoes, here for the example shown in Figure 4. The lower progression 502 shows the original graphical progression of the amplitude of the two transmitted ultrasonic pulses 202, 204 as well as the amplitude of the received echoes, while the upper progression 504 shows the progression shifted to the left by the distance between the two transmitted ultrasonic pulses 202, 204.

[0057] In the example of Figure 5, it can be seen that the three objects 402, 404, and 406 only cause five echoes 506, 508, 510, 512, and 514 when two ultrasonic pulses 202, 204 are emitted, although six echoes would actually be expected. In this example, this is due to the fact that objects 402 and 404 are at the same height at the time the second ultrasonic pulse 204 strikes, so the corresponding echo 508 represents a superposition of two echoes and has a corresponding (wider) shape.

[0058] The echoes are now each assigned a probability 516, which has a maximum value of 1. In particular, for echo 508, this probability is less than 1, since the echo has a broad shape in the original curve representation 502. Only if this probability exceeds a certain limit is the corresponding echo used to determine a relative velocity according to the example in Figure 1-3. In this case, the probability must be greater than 0.5 (> 0.5) for the echo to be used to determine a relative velocity. In the original curve representation 502, this is only the case for echoes 506 and 512. Echo 506 is caused by the closest object 402, while echo 512 is caused by the furthest object 406, so that the corresponding relative velocity can be determined for these objects 402, 406.

[0059] In the example, no relative speed can be determined for object 404 because the corresponding echoes were not assigned a sufficient probability. Since object 404 is not the closest object to the car, it does not pose an immediate threat to the car's driving behavior. In the example of Figures 4 and 5, one can therefore wait until the next measurement cycle to determine the relative speed of object 404. Another possibility for determining the relative speed of object 404 would be, for example (but not exclusively), the addition of additional sensors (for example, a radar, a camera, and / or a LIDAR) to confirm the corresponding echoes and subsequently determine the relative speed of object 404.

[0060] Figure 6 again shows vehicle 102 moving in direction 112, as well as ultrasonic sensors 104, which emit ultrasonic pulses 114 and receive their echoes. Figure 4 also shows objects 602, 604, and 606 with their corresponding relative velocities in direction 112 (602 = 0 m / s, 604 = 3 m / s, 606 = 9 m / s). Here, vehicle 102 also has a velocity of 3 m / s in direction 112.

[0061] In Figure 6, the procedure for determining the relative speed of objects 602, 604, 606 is analogous to the procedure explained in the example in Figure 1-3. However, object 602 is located in close proximity to vehicle 102 or the ultrasonic sensors 104, so that a superposition of a transmitted second ultrasonic pulse and the reception of an echo on the previously transmitted ultrasonic pulse can be assumed.

[0062] Figure 7 again shows the graphical progression of the amplitude of the two transmitted ultrasonic pulses 202, 204 as well as the amplitude of the received echoes, here for the example shown in Figure 6. The lower progression 702 shows the original graphical progression of the amplitude of the two transmitted ultrasonic pulses 202, 204 as well as the amplitude of the received echoes, while the upper progression 704 shows the progression shifted to the left by the distance between the two transmitted ultrasonic pulses 202, 204.

[0063] In the example of Figure 7, it can be seen that the three objects 602, 604, and 606 only cause five echoes 706, 708, 710, 712, and 714 when two ultrasonic pulses 202, 204 are emitted, although six echoes would actually be expected. In this example, this is due to the fact that object 602 is located in close proximity to vehicle 102 or ultrasonic sensors 104, and the echo caused by object 602 cannot be displayed on ultrasonic pulse 202 because it is overlaid by the emission of ultrasonic pulse 204.

[0064] The echoes are now each assigned a probability 716. Only if this probability exceeds a certain limit is the corresponding echo used to determine a relative velocity according to the example in Figure 1-3. In this case, the probability must be greater than 0.5 (> 0.5) for the echo to be used to determine a relative velocity. In the original curve representation 702, this is only the case for echoes 708 and 712, since in the original curve representation 702 an echo caused by the closest object 602 is missing because it is superimposed by the emission of the ultrasonic pulse 204. Echo 708 is caused by object 604, and echo 712 by the furthest object 606, so that the corresponding relative velocity can be determined for these objects 604, 606.

[0065] In the example, no relative speed can be determined for object 602 because the corresponding echo is missing in the original course 702 or has not been assigned a sufficient probability. Object 602 is the object that is closest to the car. One possibility to determine the relative speed of object 602 would be, for example (but not exclusively), the addition of additional sensors (for example, a radar, a camera and / or a LIDAR) to confirm the corresponding echoes and subsequently determine the relative speed of object 602. Another alternative would be to initiate an appropriate countermeasure (for example, emergency braking, aborting an automatic parking maneuver, aborting autonomous driving, displaying a warning message, emitting a warning tone) of the vehicle 102, or any other conceivable countermeasure to prevent endangering the vehicle 102.

[0066] Figure 8 again shows vehicle 102 moving in direction 112, as well as ultrasonic sensors 104, which emit ultrasonic pulses 114 and receive their echoes. Figure 4 also shows objects 802, 804, and 806 with their corresponding relative velocities in direction 112 (802 = 0 m / s, 804 = 3 m / s, 806 = 9 m / s). Here, vehicle 102 also has a velocity of 3 m / s in direction 112.

[0067] In Figure 8, the procedure for determining the relative speed of objects 802, 804, 806 is analogous to the procedure explained in the example in Figure 1-3. However, object 802 is located in close proximity to vehicle 102 or the ultrasonic sensors 104, so that a superposition of a transmitted second ultrasonic pulse and the reception of an echo of a previously transmitted ultrasonic pulse can be assumed.

[0068] Figure 9 again shows the graphical progression of the amplitude of the two transmitted ultrasonic pulses 202, 204 as well as the amplitude of the received echoes, here for the example shown in Figure 8. The lower progression 902 shows the original graphical progression of the amplitude of the two transmitted ultrasonic pulses 202, 204 as well as the amplitude of the received echoes, while the upper progression 904 shows the progression shifted to the left by the distance between the two transmitted ultrasonic pulses 202, 204.

[0069] In the example of Figure 9, it can be seen that the three objects 802, 804, and 806 only cause five echoes 906, 908, 910, 912, and 914 when two ultrasonic pulses 202, 204 are emitted, although six echoes would actually be expected. In this example, this is due to the fact that object 802 is located in close proximity to vehicle 102 or ultrasonic sensors 104, and the echo caused by object 802 cannot be displayed on ultrasonic pulse 202 because it is overlaid by the emission of ultrasonic pulse 204.

[0070] Each echo is now assigned a probability 916. Only if this probability exceeds a certain limit, the corresponding echo is used to determine a relative speed according to the example in Figure 1-3. In this case, the probability must be greater than 0.5 (> 0.5) for the echo to be used to determine a relative speed. This is, in the This is only the case for echoes 908 and 912 in the original curve representation 902, since an echo caused by the closest object 802 is missing in the original curve representation 902 because it is overlaid by the emission of the ultrasonic pulse 204. Echo 908 is caused by object 804, while echo 912 is caused by the furthest object 806, so that the corresponding relative speed can be determined for these objects 804, 806.

[0071] In the example, no relative speed can be determined for object 802 because the corresponding echo is missing in the original curve 902 or has not been assigned a sufficient probability. Object 802 is the object that is closest to the car. One possibility for determining the relative speed of object 802 would be, for example (but not exclusively), the addition of additional sensors (for example, a radar, a camera, and / or a LIDAR) to confirm the corresponding echoes and subsequently determine the relative speed of object 802. Reference could also be made to the previous or next measurement cycle in which no echo was superimposed on the emitted ultrasonic pulse 204 in order to derive a corresponding relative speed for object 802 and to determine whether, for example, a dangerous situation exists.

[0072] Although the invention has been fully illustrated and described in the drawings and the foregoing description, this illustration and description is to be considered as exemplary and not restrictive; the invention is not limited to the disclosed examples.

[0073] Those skilled in the art will understand that aspects of the present invention may be embodied as a device, method, or computer program or computer program product. Accordingly, aspects of the present invention may take the form of a purely hardware embodiment, a purely software embodiment (including firmware, in-memory software, microcode, etc.), or an embodiment combining software and hardware aspects, all of which may be referred to generally herein as a "circuit," "module," or "system." Furthermore, aspects of the present invention may take the form of a computer program product carried by one or more computer-readable media in the form of computer-executable code. A computer program also includes the Computer executable code. "Computer executable code" may also be referred to as "computer program instructions."

[0074] Any combination of one or more computer-readable media may be used. The computer-readable medium may be a computer-readable signal medium or a computer-readable storage medium. A "computer-readable storage medium," as used herein, includes a tangible storage medium capable of storing instructions executable by a processor of a computing device. The computer-readable storage medium may be referred to as a computer-readable non-transitory storage medium. The computer-readable storage medium may also be referred to as a tangible computer-readable medium. In some embodiments, a computer-readable storage medium may also be capable of storing data that allows it to be accessed by the processor of the computing device.Examples of computer-readable storage media include, but are not limited to: a floppy disk, a magnetic hard disk, a solid-state hard disk, flash memory, a USB flash drive, random access memory (RAM), read-only memory (ROM), an optical disk, a magneto-optical disk, and the processor's register file. Examples of optical disks include compact disks (CDs) and digital versatile disks (DVDs), for example, CD-ROM, CD-RW, CD-R, DVD-ROM, DVD-RW, or DVD-R disks. The term computer-readable storage medium also refers to various types of recording media suitable for being retrieved by the computing device over a network or communications link. For example, data may be retrieved via a modem, over the Internet, or over a local area network.Computer-executable code embodied on a computer-readable medium may be transmitted over any suitable medium, including, but not limited to, wireless, wired, fiber optic, RF, etc., or any suitable combination of the foregoing media.

[0075] A computer-readable signal medium may include a propagated data signal containing the computer-readable program code, for example, in a baseband signal or as part of a carrier signal (carrier wave). Such a propagated signal may be in any form, including, but not limited to, an electromagnetic form, an optical form, or any suitable combination thereof. A computer-readable signal medium may be any computer-readable medium other than a computer-readable storage medium that encodes a program for use by or in connection with a system, device or apparatus for carrying out instructions.

[0076] "Computer memory" or "memory" is an example of a computer-readable storage medium. Computer memory is any memory directly accessible by a processor.

[0077] "Computer storage" or "data storage" is another example of a computer-readable storage medium. Computer storage is any non-transitory computer-readable storage medium. In some embodiments, computer memory may also be computer data storage, or vice versa.

[0078] A "processor," as used herein, includes an electronic component capable of executing a program- or machine-executable instruction or computer-executable code. Reference to the computing device including a "processor" should be interpreted to potentially include more than one processor or processing cores. The processor may, for example, be a multi-core processor. A processor may also refer to a collection of processors within a single computer system or distributed across multiple computer systems. The term computing device or computer should also be interpreted to potentially refer to a collection or network of computing devices or computers, each including a processor or processors.The computer-executable code may be executed by multiple processors, which may be distributed within the same computing device or even across multiple computers.

[0079] Computer-executable code may comprise machine-executable instructions or a program that causes a processor to perform an aspect of the present invention. Computer-executable code for performing operations for aspects of the present invention may be written in any combination of one or more programming languages, including an object-oriented programming language such as Java, Smalltalk, C++, or the like, and conventional procedural programming languages ​​such as the "C" programming language or similar programming languages, and translated into machine-executable instructions. In some cases, the computer-executable code may be in the form of a high-level programming language or in a pre-translated form and used in conjunction with an interpreter that generates the machine-executable instructions.

[0080] The computer executable code may run entirely on a user's computer, partially on the user's computer, as a standalone software package, partially on the user's computer and partially on a remote computer, or entirely on the remote computer or server. In the latter case, the remote computer may be connected to the user's computer through any type of network, including a local area network (LAN) or a wide area network (WAN), or the connection may be made to an external computer (for example, over the Internet using an Internet service provider).

[0081] The computer program instructions can be executed on one or more processors. In the case of multiple processors, these can be distributed across several different entities (e.g., clients, servers). Each processor could execute a portion of the instructions intended for the respective entity. Therefore, when referring to a system or method that encompasses multiple entities, the computer program instructions are understood to be adapted to be executed by a processor assigned to or associated with the respective entity.

[0082] Aspects of the present invention are described with reference to flowchart illustrations and / or block diagrams of methods, devices (systems), and computer program products according to embodiments of the invention. It is noted that each block or portions of the blocks of the flowcharts, illustrations, and / or block diagrams may be implemented by computer program instructions, optionally in the form of computer-executable code. It is further noted that combinations of blocks in different flowcharts, illustrations, and / or block diagrams may be combined if they are not mutually exclusive. These computer program instructions may be assigned to a processor of a general-purpose computer, special-purpose computer, or other programmable Data processing apparatus may be provided to produce a device such that instructions executed via the processor of the computer or other programmable data processing apparatus produce means for performing the functions / steps defined in the block or blocks of flowcharts and / or block diagrams.

[0083] These computer program instructions may also be embodied in a computer-readable medium that contains a computer or other programmable Data processing devices or other devices can control that they are directed to a function in a particular manner such that the instructions stored on the computer-readable medium produce a manufactured article, including instructions that implement the function / step specified in the block or blocks of the flowcharts and / or block diagrams.

[0084] The computer program instructions may also be stored on a computer, other programmable data processing device, or other device to cause the execution of a series of process steps on the computer, other programmable data processing device, or other device to produce a computer-executed process, such that the instructions executing on the computer or other programmable device produce methods for implementing the functions / steps defined in the block or blocks of flowcharts and / or block diagrams. LIST OF REFERENCE SYMBOLS 102 vehicles 104 ultrasonic sensors 106, 108, 110 Object 112 direction 114 Ultrasonic pulse (path of transmission and reception) 202 Emitted ultrasonic pulse 204 Emitted ultrasonic pulse 206 Received Echo 208 Received Echo 210 Distance / Position 212 Distance / Position 302 Original History 304 Shifted History 306 Distance / Position 402, 404, 406 Object 502 Original History 504 Shifted History 506, 508, 510, 512, 514 Received Echo 516 probabilities 602, 604, 606 Object 702 Original History 704 Shifted History 706, 708, 710, 712, 714 Received Echo 716 probabilities 802, 804, 806 Object 902 Original History 904 Shifted History 906, 908, 910, 912, 914 Received Echo 916 probabilities

Claims

CLAIMS 1. A method for ultrasonic sensor operation, the method comprising Controlling at least one ultrasonic sensor (104) to emit at least two ultrasonic pulses (202, 204) during a measuring cycle, wherein there is a time interval between the ultrasonic pulses (202, 204), wherein the measuring cycle is carried out cyclically and repeatedly; Receiving echoes (206, 208, 506, 508, 510, 512, 514, 706, 708, 710, 712, 714, 906, 908, 910, 912, 914) resulting from the ultrasonic pulses, the echoes being caused by an object (106, 108, 110, 402, 404, 406, 602, 604, 606, 802, 804, 806); Determining a relative speed of the ultrasonic sensor (104) to the object based on the temporal position of the ultrasonic pulses (202, 204) to one another and their echoes (206, 208, 506, 508, 510, 512, 514, 706, 708, 710, 712, 714, 906, 908, 910, 912, 914) to one another within the measuring cycle.

2. The method according to claim 1, further comprising determining a spatial position of the object relative to the ultrasonic sensor (104) on the basis of at least one of the two ultrasonic pulses (202, 204) and the echo (206, 208, 506, 508, 510, 512, 514, 706, 708, 710, 712, 714, 906, 908, 910, 912, 914) associated with the respective ultrasonic pulse.

3. The method according to claim 1 or 2, wherein the relative speed is determined analytically, wherein the temporal position of the ultrasonic pulses relative to one another comprises their temporal pulse spacing and the temporal position of the echoes relative to one another comprises a temporal echo spacing of the echoes relative to one another, wherein the relative speed is determined on the basis of the temporal pulse spacing and the temporal echo spacing or the spatial position comprises a distance (212, 306), wherein the relative speed is determined using a difference between the distances determined on the basis of the two ultrasonic pulses and the at least one temporal spacing.

4. Method according to one of the preceding claims 1-2, wherein the determination of the relative speed is carried out by a machine learning module, wherein the machine learning module is trained to determine the relative speed of the ultrasonic sensor to the object on the basis of the temporal position of the ultrasonic pulses relative to one another and their echoes relative to one another.

5. Method according to one of the preceding claims, wherein each echo is assigned a probability (516, 716, 916), the probability comprising that the at least one object actually caused the respective echo, wherein the relative speed is determined only using the echoes whose probability is above a predetermined threshold.

6. The method according to claim 6, wherein the probability (516, 716, 916) is influenced by at least one of the following factors: by a difference in the signal propagation time of the ultrasonic pulses from the transmission to the reception of the respective echoes, whereby a smaller difference leads to an increased probability; by a difference in the determined relative speed of the object in the current measurement cycle and in an immediately previous measurement cycle, whereby a smaller difference leads to an increased probability; by a difference in the amplitudes of the received echoes associated with the object, whereby a smaller difference leads to an increased probability; by a width of the echo, whereby a sharper echo leads to a higher probability than a wide echo;from a shape of a time-amplitude curve of the received echoes assigned to the object, where a more similar shape leads to a higher probability; whether the probability of the echoes in the immediately previous measurement cycle lies above a threshold value and the echoes were thus determined to belong to the object, where a probability above the threshold value in the immediately previous measurement cycle leads to an increased probability in the current measurement cycle; from a further confirmation of the presence of the object at a distance from the ultrasonic sensor corresponding to the signal propagation time using another sensor system, where the other sensor system comprises at least one camera and / or at least one radar and / or at least one LIDAR.

7. Method according to one of the preceding claims, further comprising for determining the relative speed: varying, in different measuring cycles, the number of emitted ultrasonic pulses (202, 204) and / or the temporal pulse spacing and / or the temporal pulse duration and / or a duration of the measuring cycle, wherein when controlling a plurality of ultrasonic sensors (104) the respective ultrasonic sensors (104) emit a different number of ultrasonic pulses (202, 204) and / or use a different temporal pulse spacing and / or use a different temporal pulse duration and / or use a different duration of the measuring cycle, wherein preferably the duration of the measuring cycle is varied between 25 ms and 100 ms, and / or the temporal pulse spacing is varied between 0.5 ms and 10 ms and / or the temporal pulse duration is varied between 0.5 ms and 5 ms.

8. A computer program product, in particular a computer-readable storage medium, wherein the computer program product comprises computer-executable code, wherein the code is executable by at least one processor of a computer device to cause the computer device to perform the method according to claim 1. TI 9. Ultrasonic sensor (104), in particular for use in a vehicle (102), wherein the ultrasonic sensor is designed to carry out the method according to claim 1.

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