Method for measuring a lateral environment region of a vehicle, measuring device and vehicle

Abstract

The invention relates to an ultrasonic measuring method having the following steps: actuating ultrasonic transceivers at a plurality of transmit-receive positions along a lateral direction in order to transmit corresponding transmit signals and to receive corresponding receive signal curves in a transverse direction; identifying a plurality of echo signals in each receive signal curve; forming a plurality of reflection points, wherein each reflection point is triangulated using two corresponding receive signal curves and the corresponding echo signals from each of the two receive signal curves and then stored in the plurality of reflection points; forming pairs of primary and secondary reflection points using a position-based criterion, the primary and secondary reflection points being identified as directly or indirectly reflected reflection points on the same object portion; and e) determining an object height at each of the reflection points as high, if the reflection point is the primary reflection point of one of the formed pairs of reflection points, and as low, if the object height is not formed into a pair of reflection points with the corresponding reflection point as primary or secondary reflection point. The method can produce a large number of information measurement points. The invention also relates to a measuring device and a vehicle.

Description

Technical Field

[0001] This invention relates to the field of parking assistance systems for motor vehicles, and more particularly to a method and measuring apparatus for measuring the lateral environment of a vehicle using a lateral ultrasonic transceiver, and to a corresponding vehicle. Background Technology

[0002] Modern vehicles have parking assistance systems configured to measure the vehicle's lateral environment to semi-autonomously or fully autonomously identify parking spaces and park the vehicle within them. One known method for measuring the lateral environment uses an ultrasonic transceiver to determine the distance to objects in the lateral environment based on the time of flight between transmitting a signal and receiving the associated echo signal.

[0003] DE102005044050A1 also teaches a method for determining the parking space of a motor vehicle, wherein the height of objects in the lateral environment of the motor vehicle is evaluated based on whether a single echo signal is received in response to the transmission of a transmitted signal or whether two echo signals forming a double echo are received in the same received signal waveform.

[0004] Based on this idea, DE102007035219A1 teaches how to generate object classification signals based on multiple local maxima in the received signal.

[0005] DE10351314A1 teaches a method for determining the location of a reflecting point on an object in the lateral environment of a motor vehicle. Corresponding transmission signals are emitted from two different locations, the associated echo signals are received, and the corresponding distances are determined. Based on the two distance measurements and the distance between the two locations, the precise location of the object is then calculated using triangulation or trilateration methods. Summary of the Invention

[0006] In this context, one object of the present invention is to improve the measurement of the lateral environment of a vehicle.

[0007] Therefore, the first aspect proposes a method for measuring the lateral environment of a vehicle equipped with at least one lateral ultrasonic transceiver. The method includes the following steps: a) activating at least one ultrasonic transceiver at multiple transmitting and receiving positions along the lateral direction of travel of the vehicle to transmit a corresponding transmitted signal in a lateral direction to the vehicle's direction of travel and to receive a corresponding received signal waveform reflected from the lateral environment; b) identifying multiple echo signals in the corresponding received signal waveforms; c) forming a set of reflection points by performing multiple trilaterations on corresponding reflection points in the lateral environment based on two corresponding received signal waveforms from the multiple received signal waveforms and on the corresponding echo signals from each of the two received signal waveforms, and storing the set of reflection points in the set of reflection points; d) forming multiple pairs of reflection points consisting of corresponding primary reflection points and corresponding secondary reflection points in the set of reflection points, which are identified as reflection points directly and / or indirectly reflected from the same object portion in the lateral environment based on at least position-based criteria; and e) if the reflection point in question is the primary reflection point of one of the formed pairs of reflection points, the object height at the corresponding one of the reflection points in the lateral environment is determined to be high, and if no pair of reflection points including the reflection point in question as a primary or secondary reflection point is formed in step d), it is determined to be low.

[0008] Therefore, the proposed method specifically employs the idea of ​​determining object height based on the presence of dual echoes, which occur when a transmitted signal is reflected directly and indirectly from the same part of the object. However, instead of starting at the level of a single echo signal waveform used to identify such dual echoes, it first performs trilaterations on multiple reflection points based on multiple echo signal waveforms from multiple echo signal waveforms, and then determines the primary and secondary reflection point pairs based on a location-based criterion, where the primary and secondary reflection points do not need, or necessarily need, to be trilaterated based on the same received signal waveform. The height of the tall object is then determined, where a corresponding pair of points can be formed.

[0009] In particular, this method offers the advantage of obtaining a significantly larger number of meaningful measurement points. Therefore, it is possible to better reconstruct the contours of objects in the lateral environment. Specifically, obstacles receding in the lateral environment and those located between and thus occluded by other obstacles in the lateral environment can be visible or measurable.

[0010] In this context, "measurement point" should be understood in particular to refer to the three-sided measurement location of the reflection point and the determination of the relevant object height as "high" or "low".

[0011] Lateral ultrasonic receivers are specifically attached to one side of the vehicle or configured to transmit ultrasonic signals or ultrasonic waveforms into the lateral environment of the vehicle and receive them from there.

[0012] The transmitted signal from an ultrasonic transceiver can be a signal lobe, which can be particularly wide. "Transmitting the transmitted signal in the lateral direction" can therefore be understood to specifically mean that the maximum signal strength of the transmitted ultrasonic signal is transmitted in the lateral direction. The signal strength may decrease laterally. In other words, the transmitted signal can be transmitted within an angular range, such as 30°, 60°, 90°, 120°, or up to 180°, or any other value between 0° and 180°, where the maximum signal strength is transmitted in the lateral direction.

[0013] In this context, "signal" should be understood specifically as a signal pulse, the time range of which is defined by the time position of the maximum signal strength and the pulse width surrounding that maximum value. Conversely, "signal waveform" should be understood specifically as the distribution of signal strength transmitted or received over a longer period of time. A signal waveform may include one or more signals or signal pulses.

[0014] "Echo signal" should be understood in particular as a previously transmitted signal reflected from the vehicle's lateral environment.

[0015] In this context, "multiple" should be understood as three or more, preferably 10 or more, and very particularly preferably 50 or more. In the current context, "multiple" should be understood as a number of two or more.

[0016] Specifically, a transmission signal or transmission signal pulse is transmitted at the corresponding transmission location during the transmission time. The received signal waveform is received at the corresponding reception location during a specific reception period. One or more echo signals are then identified from this waveform.

[0017] The proposed method can be implemented in particular by having the vehicle travel to a first transmitting and receiving position, stop, transmit a signal, fully receive the received signal waveform, and then the vehicle travel to the next transmitting and receiving position, etc. In this case, the term "transmitting and receiving position" refers to the well-defined locations for transmitting and receiving signals.

[0018] The proposed method can also be performed, in particular, when the vehicle is in motion. In this case, the term "transmit and receive position" refers to multiple positions along the lateral or driving direction of the vehicle, from the transmission of the transmitted signal to the completion of the reception of the echo signal waveform. In this case, a specific transmission position can be identified for each transmitted signal, and a corresponding echo signal reception position can be determined for each identified echo signal. This can be achieved, in particular, based on the echo signal reception time and the speed data transmitted by the odometer unit.

[0019] The number of echo signals can be "identified" in parallel with or subsequently with the reception of the corresponding received signal waveform. Specifically, the corresponding received signal waveform can be buffered and stored. This identification can be based on the occurrence of the maximum amplitude (signal strength) value in the corresponding received signal waveform. In particular, a predetermined or variable threshold can be applied, and if the amplitude (signal strength) in the corresponding received signal waveform exceeds the threshold, an echo signal can be identified.

[0020] The term "reflection point" specifically refers to a location on the surface of an object in the lateral environment from which a direct reflection of the transceiver actually or hypothetically occurs, and from which the echo signal is reflected back to the transceiver.

[0021] The trilateration of the reflection point should be understood specifically as using a trilateration method to determine the location of the reflection point. Specifically, the two-dimensional location of the reflection point is determined here in a plane extending laterally and laterally. During the trilateration, the location of the reflection point is determined, in particular, based on the time difference between the transmission of the corresponding transmitted signal and the reception of the corresponding echo signal, and based on the distance between the transmission and reception locations associated with the corresponding transmitted and echo signals. Specifically, the time difference measured between the transmission of the transmitted signal and the reception of the first echo signal allows the distance from the associated transmission and reception locations to the reflection point to be determined by multiplying half of the time difference by the speed of sound. Thus, the location of the reflection point is specifically generated as the intersection of a circle around a first transmission and reception location with a radius of a first specific distance and a circle around a second transmission and reception location with a radius of a second specific distance.

[0022] "Forming a set of reflection points" should be understood to specifically refer to repeatedly selecting two echo signals from two essentially arbitrary received signal waveforms in each case, and performing trilateration on the relevant reflection points. The trilateration positions of at least the reflection points are then stored in this set of reflection points. This set of reflection points can, in particular, be stored as a data structure (e.g., a list, array, or graph) in a volatile or non-volatile storage device.

[0023] In each case, the two echo signals can be selected, for example, from the received signal waveforms received at adjacent transmitting and receiving locations. In this case, a particular advantage is the ease of assigning which two echo signals from adjacent transmitting and receiving locations should be trilaterated with each other separately. However, in each case, it is also possible to select two echo signals from transmitting and receiving locations that are not directly adjacent.

[0024] "Primary reflection point" should be understood specifically as one of the reflection points in the set, at which a direct reflection occurs back to the ultrasonic transceiver. "Secondary reflection point" should be understood specifically as one of the reflection points in the set, which is measured trilaterically if two reflections occur in the lateral environment before the echo signal returns to the ultrasonic transceiver. The secondary reflection point is therefore specifically a dummy reflection point. Typically, this is because neither reflection occurs at the trilater measurement location of the secondary reflection point. Instead, the dummy secondary reflection point specifically indicates the location where a hypothetical directly reflected echo signal would be reflected if it were received simultaneously with an indirectly reflected echo signal.

[0025] When multiple pairs are formed from corresponding primary and secondary reflection points, multiple first reflection points can be selected from the set of reflection points, particularly sequentially. For each first reflection point, a check can be performed to determine whether a second reflection point exists in the set of reflection points that meets at least a location-based criterion. The search for such a second reflection point in the set of reflection points can, in principle, be extended to the entire set of reflection points, to selected portions thereof, and particularly to reflection points for trilateration using echo signals from received signal waveforms other than the first reflection points. If such a second reflection point is found, it can be specifically determined or assumed that the first reflection point is the primary reflection point, and the second reflection point is a related dummy secondary reflection point arising from multiple reflections of the transmitted signal from the same part of the object.

[0026] In this context, "the same object portion" should be understood specifically as a portion of the same object in the lateral environment. This object portion is particularly the portion illuminated by the signal lobes of the emitted signal from the same object in the lateral environment.

[0027] Therefore, in step e), the trilateration positions of tall objects located at each of the primary reflection points identified in this way as a pair of reflection points can be specifically determined, and the trilateration positions of low objects located at each of the reflection points in the set of reflection points that are not identified as primary or secondary reflection points in a pair of reflection points can also be determined. In particular, the trilateration positions of reflective surfaces without objects, or at least without objects, located at those reflection points in the set of reflection points identified as secondary reflection points in a pair of reflection points can also be determined.

[0028] In this context, "high" should be understood specifically as the height at which objects or obstacles in the lateral environment should not be crossed or touched when parking. "Low" should be understood specifically as the height at which objects or obstacles in the lateral environment can be crossed when parking, that is, in particular, a typical curb height of up to 15 cm.

[0029] It should also be noted that the term "primary reflection point" is used below and in the claims—both referring to "the reflection point that has been identified as the primary reflection point in a pair of reflection points" (especially when discussing step e) and "the first reflection point for which a suitable second reflection point that meets the criteria is sought in order to determine whether the first reflection point is the primary reflection point in a pair of reflection points" (especially when discussing step d).

[0030] "A pair of reflection points" and / or "double echoes" should be understood here and below as a pair formed by a primary reflection point and an associated secondary reflection point, for which it is assumed that they represent the echo signal directly reflected and the echo signal reflected multiple times from the same part of the object and another reflection point, or based on such echo signals for trilateration.

[0031] According to one embodiment, the criteria in step e) include the fact that the corresponding secondary reflection points are arranged within a geometric search window defined relative to the corresponding primary reflection point.

[0032] The search window can be defined, in particular, in a two-dimensional plane that spans horizontally and laterally.

[0033] The lateral range of the geometric search window can be limited to a distance within the time difference between the arrival of the direct reflected echo signal and the multiple reflected echo signals, which is expected when double echoes occur. Specifically, the lateral range of the geometric search window can be limited to a distance that the ultrasound preferably covers within 2 ms, and particularly preferably within 1 ms.

[0034] The lateral range of the geometric search window can be limited to the distance between two transmitting and receiving positions (the lateral distance between the two measurement positions).

[0035] The spatial location of the second reflection point within a geometric search window defined in this way, based on the first reflection point, can be a necessary condition for the existence of a pair of reflection points. By restricting the search for secondary reflection points to a geometric search window defined in this way, the number of computational operations required to perform the search can be further reduced.

[0036] According to another embodiment, the geometric search window includes at least one reflection point that has been trilated based on two corresponding echo signals identified in the received signal waveform, rather than based on two echo signals from which the main reflection point has been trilated.

[0037] The geometric search window may also preferably include at least one reflection point that has been trilaterated based on two corresponding echo signals identified in the same received signal waveform as the two echo signals, and the main reflection point is trilaterated based on the two echo signals, but the two echo signals are different.

[0038] Measurements of the vehicle's lateral environment can be affected by many factors, particularly noise, received signals that are difficult to interpret, and obstructed objects or processes in the lateral environment. Therefore, it is possible that not all echo signals in the echo waveform can be correctly identified, or that not all echo signals are correctly identified. More meaningful measurement points can be generated, despite challenging measurement conditions, by searching for suitable secondary echoes in other received signal waveforms (i.e., searching for echo signals based on which trilaterations can be performed on secondary reflection points that meet at least location-based criteria).

[0039] According to another embodiment, the geometric search window widens laterally in the horizontal direction as the distance to the main reflection point increases.

[0040] The geometric search window can be point-like, especially at the location of the main reflection point, and widens in the lateral direction, particularly in the shape of a segment of triangle or circle away from the measurement location.

[0041] When using a location-based criterion to search for suitable secondary reflection points, this configuration of the geometric search window reduces the probability that two primary reflection points are incorrectly identified as a pair of reflection points formed by the primary and secondary reflection points.

[0042] According to another embodiment, among a plurality of reflection points that meet the criteria for the corresponding primary reflection point, the reflection point closest to the primary reflection point is selected as the secondary reflection point in the pair to be formed.

[0043] Specifically, only the reflection point closest to the primary reflection point can be identified as a secondary reflection point in a pair of reflection points including the primary reflection point. Therefore, other secondary reflection points that also satisfy this criterion are not "consumed"; they can subsequently be selected as potential primary reflection points for searching suitable secondary reflection points. Thus, depending on the situation to be measured, the number of meaningful measurement points can be advantageously further increased.

[0044] According to another embodiment, the echo signals identified in the corresponding received signal waveforms are sorted according to their time order, and in step c), echo signals from the same order of echo signal waveforms received at adjacent receiving positions are used to perform trilateration on the corresponding reflection points.

[0045] The term "sequence" here should be understood as a number that specifically indicates the position of the echo signal in the time sequence of the echo signals. That is, "1" indicates the first echo signal in time in the waveform of the echo signal, "2" indicates the second echo signal in time in the same waveform of the echo signal, and so on.

[0046] In principle, it is conceivable to increase the number of reflection points in the set of reflection points by combining any echo signal in the received signal waveform with any echo signal in the second echo signal waveform, thereby increasing the number of measurement points to generate relevant reflection points. However, according to this embodiment, only the first echo signal in time is combined with the first echo signal in time, the second echo signal in time is combined with the second echo signal in time, and so on, to perform trilateration on the corresponding reflection points. Therefore, the amount of data to be processed can be advantageously reduced, while simultaneously increasing the significance of the amount of data to be processed.

[0047] According to another embodiment, the criteria in step e) include the fact that the order of the echo signals based on the trilateration of the secondary reflection points is one higher than the order of the echo signals based on the trilateration of the primary reflection points.

[0048] Therefore, purely as an example, it is conceivable that a reflection point measured based on a second echo signal from two received signal waveforms in a second time phase could be combined with a reflection point measured based on a third echo signal from the same or other received signal waveforms in a third time phase to form a pair of reflection points. However, using the standard of this embodiment, a reflection point measured based on a second echo signal in a second time phase cannot be combined with a first, fourth, or even later echo signal from the same or other received signal waveforms in a first, fourth, or even later time phase.

[0049] Therefore, it can advantageously reduce the amount of data to be processed, while increasing the significance of the data being processed.

[0050] According to another embodiment, the criteria in step e) include the fact that the secondary reflection point is farther away from the transmission and reception points of the echo signal associated with the primary reflection point than the primary reflection point.

[0051] Therefore, this advantageously reduces the probability that two primary reflection points that are substantially adjacent to each other in the lateral direction are mistakenly identified as a pair of reflection points formed by the primary reflection point and the secondary reflection point.

[0052] According to another embodiment, the criteria in step e) include the fact that the distance between the primary reflection point and the secondary reflection point is less than a predetermined maximum distance.

[0053] Considering the expected path lengthening of a multi-reflection echo signal compared to a directly reflected echo signal, a predetermined maximum distance can be determined. The expected path lengthening depends particularly on the installation height of the ultrasonic transceiver and the expected distance between the vehicle and the object under test. For example, considering a sound speed of 343 m / s, a path lengthening of 50 cm results in a time difference of approximately 1.5 ms. The predetermined maximum distance can be selected within the range of 1 to 2 ms, preferably 2 ms.

[0054] Therefore, the probability that a pair of reflection points formed by the primary reflection point and the assumed secondary reflection point can be incorrectly formed by two primary reflection points on different objects can be reduced.

[0055] According to another embodiment, the criteria in step e) include the fact that the signal strength of at least one echo signal based on the trilateration of the secondary reflection point is reduced by no more than a predetermined factor compared to the signal strength of at least one echo signal based on the trilateration of the primary reflection point.

[0056] In particular, due to the longer signal path in the case of multiple reflections, and because the transmitted signal has a signal lobe, that is, it is widened, the echo signal belonging to the virtual secondary reflection point should be expected to be less strong than the echo signal belonging to the relevant primary reflection point.

[0057] By taking signal strength into account, the probability of a pair of reflection points formed by the primary reflection point and the assumed secondary reflection point being incorrectly formed from two primary reflection points on different objects or parts of objects can be reduced.

[0058] According to another embodiment, the trilateration position of the corresponding reflection point and one or more optional attributes are stored in the set of reflection points for that reflection point, and steps e) and f) are performed after steps a), b) and c) are completed based on the storage location stored in the set of reflection points and the reflection point attributes stored in the applicable context.

[0059] Because multiple ultrasonic measurements are initially performed to form a complete set of reflection points before searching for paired reflection points, it is advantageous that if paired reflection points are formed solely from echo signals from two corresponding measurements, it is possible to generate other measurement points that have not yet been detected.

[0060] In particular, in addition to location, other attributes are also stored in the variants of the set of reflection points, which can make the criteria that the second reflection point must meet not only based on the relative positions of the primary and potential secondary reflection points, but also based on other factual criteria to select as the secondary reflection point associated with the primary reflection point, thereby increasing the significance of the resulting measurement points.

[0061] The attributes of the corresponding reflection point may include one or more of the following attributes: 1. the order of the echo signals in the corresponding received signal waveform, based on which the trilateration of the reflection point is performed; 2. the transmission and reception positions of one or two received signal waveforms with echo signals, based on which the trilateration of the reflection point is performed; 3. the signal strength of one or two echo signals on which the trilateration of the reflection point is based.

[0062] The second aspect proposes a method for parking a vehicle equipped with at least one lateral ultrasonic transceiver and a parking assistance system. The method of the second aspect includes: performing the method of the first aspect or its embodiments to determine the positions and object heights at a plurality of primary reflective points in the vehicle's lateral environment; determining a parking space in the lateral environment where no object height is determined to be "high"; and parking the vehicle in the parking space using the parking assistance system.

[0063] Parking assistance systems can be configured to provide instructions or commands to the human driver of the vehicle to execute appropriate steering and driving procedures. Parking assistance systems can also be configured specifically for partially or fully autonomous driving of the vehicle. Partial autonomous driving is understood, for example, as the parking assistance system controlling the steering mechanism and / or the autonomous speed level system. Fully autonomous driving is understood, for example, as the parking assistance system additionally controlling the drive and braking systems.

[0064] The parking assistance system can in particular enable the vehicle to travel at a speed preferably not exceeding 40 km / h, more preferably not exceeding 30 km / h, and most preferably at a walking speed along a driving direction parallel to the vehicle's lateral environment, in which parking space is suspected, and in the process perform the method proposed in the second aspect.

[0065] The multiple measurement points (location and object height) identified by the method in the first aspect can also optionally be combined or clustered using clustering methods. In the process based on statistical criteria, incorrect or less relevant determinations can be filtered out. Here, the accumulation of measurement points can be particularly evaluated as a criterion for highly significant measurement points, while isolated measurement points can be filtered out as irrelevant. The proposed method particularly offers the advantage of generating a large number of measurement points, which can improve the ability to apply statistical methods.

[0066] Parking space can be understood specifically as an area in the lateral environment of a vehicle where no object is positioned that is defined as “tall” and whose size is larger than that of the vehicle, meaning that vehicles can be parked parallel, diagonally, or laterally in a free area.

[0067] Parking trajectories can be determined using mathematical methods and / or machine learning, trained neural networks, etc.

[0068] PID control or similar methods can be used to guide the vehicle along a parking trajectory. During driving, further ultrasonic measurements can be performed using the methods described in the first aspect, or further measurements can be taken using other types of sensors to continuously update the acquired information about the lateral environment.

[0069] The third aspect proposes a computer program product including instructions that, when executed by a computer device, cause the computer device to perform the method according to the first or second aspect.

[0070] Computer program products, such as computer program devices, can be provided or supplied as, for example, storage media, such as memory cards, USB sticks, CD-ROMs, DVDs, or as files downloadable from a server on a network. This can be done, for example, by transmitting the corresponding files containing the computer program product or computer program device over a wireless communication network.

[0071] Computer equipment can be a component of parking assistance systems, in particular. This equipment can be embedded devices, vehicle controllers (ECUs—electronic control units), microcontrollers, industrial PCs, etc.

[0072] The fourth aspect proposes a measuring device for a parking assistance system of a vehicle equipped with at least one lateral ultrasonic transceiver. The measuring device is configured to measure the lateral environment of the vehicle and includes: a) a first unit configured to activate at least one ultrasonic transceiver at multiple transmitting and receiving positions along the lateral direction of travel of the vehicle to transmit a corresponding transmitted signal in a lateral direction transverse to the vehicle's direction of travel and receive a corresponding received signal waveform reflected from the lateral environment; b) a second unit configured to identify multiple echo signals in the corresponding received signal waveforms; c) a third unit configured to perform multi-echo analysis on corresponding reflection points in the lateral environment based on two corresponding received signal waveforms from the multiple received signal waveforms and based on the corresponding echo signals from each of the two received signal waveforms. The second trilateration is used to form a set of reflection points and store them in the set of reflection points; d) a fourth unit configured to form multiple pairs of reflection points formed by corresponding primary reflection points and corresponding secondary reflection points in the set of reflection points, which are identified as reflection points from the same object part in the lateral environment as direct and / or indirect reflections based on at least position-based criteria; and e) a fifth unit configured to determine the object height at the corresponding one of the reflection points in the lateral environment as high if the reflection point in question is the primary reflection point of one of the formed pairs of reflection points, and to determine as low if no pair of reflection points including the reflection point in question as a primary or secondary reflection point is formed in the fourth unit.

[0073] The features, advantages, and embodiments described for the method in the first aspect are also applicable to the measuring apparatus in the fourth aspect.

[0074] The various units mentioned herein can be implemented in hardware and / or software. When implemented in hardware, the corresponding unit can be, for example, a computer or microprocessor. When implemented in software, the corresponding unit can be a computer program product, function, routine, algorithm, part of program code, or executable object. Furthermore, each unit mentioned herein can also be part of a higher-level control system of the vehicle, such as a control unit (ECU: engine control unit).

[0075] The fifth aspect proposes a vehicle including a parking assistance system configured for semi-autonomous or fully autonomous driving of the vehicle, wherein the vehicle and / or the parking assistance system include the measuring device of the fourth aspect.

[0076] The vehicle is, for example, a car or truck. The vehicle preferably includes multiple sensor units configured to capture the vehicle's driving state and its environment. Examples of such sensor units are image acquisition devices such as cameras, radar (radio detection and ranging) or lidar (light detection and ranging), ultrasonic sensors, position sensors, wheel angle sensors, and / or wheel speed sensors. Each sensor unit is specifically configured to output sensor signals, for example, to a parking assistance system that performs partially or fully autonomous driving based on the captured sensor signals.

[0077] Other possible embodiments of the invention include combinations of features or embodiments not explicitly mentioned in the descriptions above or below with reference to exemplary embodiments. In such cases, those skilled in the art will also add individual aspects as improvements or additions to the corresponding basic form of the invention.

[0078] Further advantageous configurations and aspects of the invention are the subject of the dependent claims and the exemplary embodiments of the invention described below. The invention will now be explained in more detail based on preferred exemplary embodiments with reference to the accompanying drawings. Attached Figure Description

[0079] Figure 1 The bird's-eye view shows a schematic diagram of the vehicle;

[0080] Figure 2 A schematic diagram of the ultrasonic transceiver is shown in the bird's-eye view;

[0081] Figure 3 A schematic diagram of an ultrasonic transceiver as viewed along the longitudinal direction of the vehicle is shown.

[0082] Figure 4 A graph showing the intensity of the transmitted signal emitted by the ultrasonic transceiver is shown.

[0083] Figure 5A graph showing the waveform of the received signal is provided.

[0084] Figure 6 A schematic diagram illustrating the formation of double echoes in the case of high obstacles is shown;

[0085] Figure 7 A schematic diagram illustrating the absence of double echoes in the case of low obstacles is shown;

[0086] Figure 8 A schematic diagram illustrating trilateration is shown;

[0087] Figure 9 An exemplary embodiment for measuring is shown. Figure 1 A flowchart of a method for assessing the lateral environment of a vehicle;

[0088] Figure 10 A functional block diagram of a corresponding measuring device according to an exemplary embodiment is shown;

[0089] Figure 11 A vehicle is shown navigating a lateral environment and performing a method according to an exemplary embodiment;

[0090] Figure 12 A two-dimensional diagram of the non-trilate measurement reflection point is shown;

[0091] Figure 13 A two-dimensional diagram of a set of reflection points from a trilateration reflection point is shown according to an exemplary embodiment; and

[0092] Figure 14 Details from a set of reflection points are shown to explain the criteria for forming paired reflections according to an exemplary embodiment.

[0093] Unless otherwise stated, identical or functionally equivalent elements in the figures have the same reference numerals. Detailed Implementation

[0094] The basic configurations and principles used to determine distances, positions, and heights in a vehicle's lateral environment are explained by example and can be applied to all embodiments and exemplary embodiments of the present invention.

[0095] Figure 1A schematic diagram of vehicle 1 is shown from a bird's-eye view. Vehicle 1 is, for example, a car arranged in environment 2. Car 1 has a parking assistance system 3, for example, in the form of a control unit. Multiple environmental sensor devices (not all shown) are additionally arranged on car 1. The multiple environmental sensor devices include, in particular, a lateral ultrasonic transceiver 4. The ultrasonic transceiver 4 is configured to transmit ultrasonic transmission signals into environment 2, and specifically into an area of ​​environment 2 of vehicle 1, represented as lateral environment 5, and to receive ultrasonic reception signal waveforms from lateral environment 5. Parking assistance system 3 includes, in particular, a measuring device 6. The measuring device 6 is configured to determine the position and height of objects (obstacles) in lateral environment 5 using the ultrasonic transceiver 4 according to the proposed method, and output them to parking assistance system 3. Using the sensor signals captured by the environmental sensor devices and the position and height determined by the measuring device 3, parking assistance system 2 can drive car 1 semi-autonomously or even fully autonomously, and in particular park it in a parking space (not shown) in lateral environment 5. Figure 1 In addition to the ultrasonic transceiver 4 shown, the vehicle 1 may be equipped with other sensor devices. Examples of these include ultrasonic transceivers, optical sensors, video cameras, radar and / or lidar, microphones, accelerometers, antennas with coupled receivers for receiving electromagnetically transmittable data signals, etc.

[0096] Figure 2 A schematic diagram of the ultrasonic transceiver 4 as seen from a bird's-eye view is shown. Figure 3 A schematic diagram of the ultrasonic transceiver 4 as viewed along the longitudinal direction of the vehicle is shown. Figure 4 A graph showing the intensity of the transmitted signal emitted by the ultrasonic transceiver 4 is shown.

[0097] The ultrasonic transceiver 4 transmits signals along the transverse axis 7. When the ultrasonic transceiver 4 is arranged as a lateral ultrasonic transceiver 4 on one side of the vehicle 1 ( Figure 1 The transverse axis 7 is arranged transversely to vehicle 1. Figure 1 That is, laterally to the front-rear direction or longitudinal direction of vehicle 1 ( Figure 1 The emitted signal comprises a signal lobe, meaning it has an aperture angle α in the horizontal direction and an aperture angle β in the vertical direction. The cone spanned by the aperture angles α and β describes a three-dimensional surface, where the signal intensity of the emitted ultrasonic signal is reduced by a predetermined factor compared to the maximum signal intensity along the transverse axis. Figure 4 In the diagram, the angle relative to the horizontal axis is plotted on the x-axis, and the signal strength (sound pressure level in dB) is plotted on the y-axis. Curve 8 describes the distribution of signal strength in the horizontal plane, and curve 9 describes the distribution of signal strength in the vertical plane, where both the horizontal and vertical planes intersect the horizontal axis 7.

[0098] refer to Figures 1 to 5 . Figure 5 A graph showing the waveform 10 of the received signal received by the ultrasonic transceiver 4 in response to the transmission of the transmitted signal is shown. Time t is plotted on the horizontal axis, and the sensor voltage output by the ultrasonic transceiver 4 is plotted on the vertical axis. This sensor voltage indicates the intensity of the received signal captured by the ultrasonic transceiver 4, i.e., the captured sound pressure level.

[0099] At time t0, the ultrasonic transceiver 4 transmits a signal. From time t0 to time t1, the ultrasonic transceiver immediately records the reverberation of the transmitted signal. Therefore, the region of the received signal waveform 10 from t0 to t1 cannot contain any information about the lateral environment 5 of the vehicle 1, and is suppressed, for example. At time t2, the amplitude of the received signal strength increases because the first echo signal arrives from the lateral environment 5 of the vehicle 1. Time t2 in the received signal waveform 10 can be identified as the reception time of the first echo signal in the received signal waveform 10. At time t4, the amplitude of the received signal strength increases again, but does not reach the threshold voltage V. th Therefore, the region from t4 to t5 cannot be identified as an echo signal, but is instead considered an interference signal. From time t6 to time t7, a second echo signal is received from the vehicle's lateral environment 5, and this second echo signal exceeds the threshold voltage V. th Therefore, time t6 can be identified as the reception time of the second echo signal in the received signal waveform 10.

[0100] Threshold voltage V th It is not necessary to keep the received signal waveform 10 constant throughout the entire measurement. Figure 5 As shown, the threshold voltage can also change during the measurement of the received signal waveform.

[0101] It should be noted that the threshold voltage V th Essentially, it is defined empirically. Therefore, errors in identifying the echo signal in the received signal waveform are possible. Figure 5 The threshold voltage V is selected slightly differently in the middle. th In this case, the second echo signal will therefore be identified at time t4, and the third echo signal will have already been identified at time t6. The proposed method also aims to handle this situation in an improved manner.

[0102] Figure 6 A schematic diagram showing the formation of a double echo in the presence of high obstacles is shown. Figure 7 A schematic diagram is shown where there is no double echo in the case of low obstacles. (Reference) Figure 5 and Figure 1 To describe Figure 6 and Figure 7 . Figure 6 ,7 The arrows in the diagram show the propagation paths of the transmitted and echo signals.

[0103] Figure 6 This diagram illustrates how vehicle 1 travels along the lateral direction of travel 18 past parked vehicle 11 (object, obstacle). The transmitted signal emitted by ultrasonic transceiver 4 at time t0 propagates along the lateral axis 7 of vehicle 1 to a first point 12 on the surface of parked vehicle 11, is reflected from there, and the reflected echo signal propagates back along the lateral axis 7, reaching ultrasonic transceiver 4 again at time t2. The distance between ultrasonic transceiver 4 and the first point 12 can be determined by multiplying the time difference between t2 and t0 by the speed of sound, 343 m / s, and then dividing by 2. Therefore, the first point 12 is the first reflection point 12, and its distance can be determined based on the first echo signal appearing at time t2.

[0104] Another component of the transmitted signal lobe propagates in a direction diverging from the transverse axis 7 to a second point 13 on the surface of the parked vehicle 11, from where it is reflected as a second echo signal to a third point 14 on the ground 15, and from there it is reflected again to the transceiver 4, arriving at time t6. However, when evaluating the received signal waveform 10, there is no information about the actual contour of the input echo signal path. Therefore, the distance to the second virtual reflection point 16 is determined in the same manner as the first reflection point 12 described above, as follows: Figure 6 As shown, the position of the second virtual reflection point 16 is temporarily assumed to be on the horizontal axis 7, and its distance corresponds to half of the signal flight time between the transmission of the transmitted signal at time t0 and the arrival of the second echo signal at time t6.

[0105] The second reflection point 16 is also referred to as a "virtual" reflection point because, at the distance determined for it to the ultrasonic transceiver 4, or at the location where its trilateration is performed, as described below, no actual reflection occurs. Conversely, for such a virtual reflection point, if the distance is determined or the location is determined using trilateration, a reflection will occur at that location if the relevant echo signal is reflected only once rather than multiple times.

[0106] It should be noted that the first reflection point 12 on the surface of the parked vehicle 11, which cannot be determined using the method, and the point 14 on the surface of the parked vehicle 14 are located in the same object part of the vehicle 14, which is illuminated by the signal lobe of the emitted signal.

[0107] Figure 7This illustrates how vehicle 1 travels along the lateral direction of travel 18 past curb 17. A component of the signal lobe of the transmitted signal emitted at time t0 propagates from the ultrasonic transceiver 4 to a first point 12 on curb 17, is reflected from there, and the reflected echo signal reaches the ultrasonic transceiver 4 at time t2. Therefore, the first point 12 is the first reflection point 12, its distance from the first echo signal at t2 is based on... Figure 6 The driving conditions shown are determined in the same way. Although similar to... Figure 6 As shown, there may also be double reflections from the curb 17 and then from the ground 15, but in this case, the time difference between the arrival of the double-reflected echo signal and the first-reflected echo signal is very small, so that the two echo signals are identified as a single first echo signal in the received signal waveform 10. Another component of the transmitted signal lobe propagates to a second point 13 on the ground 15 and is reflected away from there away from the vehicle 1 without reaching the ultrasonic transceiver 4.

[0108] Therefore, if two echo signals that meet a specific criterion can be identified in the received signal waveform 10 to form a double echo, it can be determined that a high obstacle 11 exists in the lateral environment 5 of the vehicle 1. If only one echo signal and / or two echo signals that do not meet the specific criterion can be identified in the received signal waveform 10, it can be determined that a low obstacle 17 exists in the lateral environment 5.

[0109] However, as mentioned above, since not all echo signals in the echo signal waveform can be correctly identified in every case, it is recommended to also search for a suitable second echo signal in another echo signal waveform, which together with the first echo signal from the first echo signal waveform forms a double echo.

[0110] The correlation criteria for identifying such echo signals from the same or different echo signal waveforms can be, in particular, the spatial location of the reflection point, which can be measured trilaterally from the corresponding echo signal relative to each other.

[0111] For example, the following fact can therefore be used as a standard: the formation of the principal reflection point ( Figure 6 12) and secondary reflection point ( Figure 6 The spatial distance between the two reflection points forming a pair of reflection points (16) corresponds to the direct reflection path ( Figure 6 (4, 12, 4) and indirect reflection path ( Figure 6 The expected length difference between 4, 13, 14, and 4) is half. A maximum distance not exceeding, for example, 25 to 50 cm, and preferably 35 cm, has proven to be a good standard.

[0112] Figure 8 A schematic diagram illustrating the trilateration of the position of reflection point 12 is shown. Figure 8The illustration shows vehicles 1 and 1' passing curb 17 (a low obstacle or object) in the lateral direction 18, while another parked vehicle 11 (a high obstacle or object) is diagonally parked on curb 17. This vehicle is shown first with reference numeral 1 and second with reference numeral 1'. Correspondingly, ultrasonic transceivers 4 and 4' are indicated by reference numeral 4 at the first transmitting and receiving position and by reference numeral 4' at the second transmitting and receiving position.

[0113] At the first time of the first transmitting and receiving position of the ultrasonic transceiver 4, with reference to the above. Figures 5 to 7 The method described involves transmitting a signal and receiving a received signal waveform, and determining the distance d to the first reflection point 12 of the reflected echo signal based on the time it takes to identify the echo signal in the received signal waveform. At a second time, at the second transmitting and receiving position of the ultrasonic transceiver 4, the distance d' to the first reflection point 12 is determined in the same manner. Therefore, the position of the first reflection point 12 is taken as the intersection of a circle 19 centered at 4 with radius d around the first transmitting and receiving position and a circle 19' centered at 4' with radius d' around the second transmitting and receiving position. Thus, Figure 8 The driving configuration shown causes the position of reflection point 12 to shift laterally relative to the transverse axes 7, 7' of the ultrasonic transceivers 4, 4'. Therefore, trilateration can improve the accuracy of the actual position of reflection point 12 compared to the initial assumed position at the corresponding intersection of the transverse axes 7, 7' and circles 19, 19'.

[0114] Figure 9 A flowchart of a method according to an exemplary embodiment is shown. Figure 10 A functional block diagram of a measuring device 6 for measuring the lateral environment 5 of a vehicle 1, according to this exemplary embodiment, is shown. Figure 11 A vehicle 1 is shown driving through a lateral environment 5 and performing a method according to an exemplary embodiment.

[0115] Figure 11 The vehicle 1 shown is Figure 1 The vehicle shown has a parking assistance system 3, a measuring device 6, and an ultrasonic transceiver 4. The measuring device 6 includes first to fifth units 21-25. Figure 10 Multiple vehicles (tall objects, obstacles) 31, 32, and 33 are parked in the lateral environment 5 of the vehicles. In this case, the front of the vehicle 32 parked in the middle is positioned significantly rearward in the lateral direction compared to the front of the vehicles 31 and 33 parked on the sides.

[0116] According to the proposed parking method according to the exemplary embodiment, the parking assistance system 3 causes the vehicle 1 to move along the lateral direction 18 at multiple transmitting and receiving positions 40, and in the process performs the parking assistance method according to the exemplary embodiment. Figure 9 The measurement method is shown in the figure.

[0117] refer to Figures 9 to 11 .

[0118] In step S1 of the proposed measurement method according to an exemplary embodiment, the first unit 21 of the measuring device 6 activates the ultrasonic transceiver 4 at a plurality of transmitting and receiving positions 40, thereby causing it to transmit a first transmitted signal along its lateral axis 70 in the lateral direction 20 and receive a first reflected received signal waveform from the lateral environment 5. Figure 5 (10) The ultrasonic transceiver provides the received signal waveform to the measuring device 6.

[0119] For ease of understanding only, it can be assumed here that, as part of the proposed parking method, the vehicle travels to a corresponding transmit and receive position 40, stops there, transmits a transmit signal and receives a receive signal curve, and then the vehicle 1 travels along the lateral direction 18 to the next transmit and receive position 40. In this case, the term "transmit and receive position" precisely refers to a corresponding position. However, the proposed method is not limited to this and can also be performed when the vehicle 1 is traveling continuously.

[0120] In step S2 of the proposed method, the second unit 22 identifies the corresponding received signal waveform for each transmit and receive position 40. Figure 5 In the case of multiple echo signals in 10), the second unit 21 preferably identifies the signal strength in the corresponding received signal waveform that is higher than a predetermined or variable threshold. Figure 5 V in th All echo signals.

[0121] In step S3, the third unit 23 forms a set of reflection points by repeatedly measuring the positions of the corresponding reflection points in the lateral environment. Figure 13 The 100 in the middle), based on two corresponding received signal waveforms from multiple received signal waveforms at the corresponding transmit and receive positions 40. Figure 5 10) and the corresponding echo signal based on each of the two received signal waveforms (in the image) Figure 5 10 in the group), and store it in the group with the reflection point ( Figure 13 (100) in.

[0122] Figure 12 A two-dimensional diagram of a set of non-trilate measurement reflection points 100 is shown. Figure 12In the diagram, reflection points 110, 120, 130, and 140 are plotted, assuming that the corresponding echo signal identified in step S2 is directly reflected at the corresponding transmit and receive position 40 and along the corresponding transverse axis 70 of the ultrasonic transceiver 4. In other words, for the corresponding identified echo signal, reflection points 110, 120, 130, and 140 are plotted along the corresponding transverse axis 70 at a certain distance from the transmit and receive position 40 of the relevant echo signal waveform. This distance corresponds to half the time difference between the transmission of the transmitted signal and the reception of the received signal waveform multiplied by the speed of sound.

[0123] In particular, Figure 12 The diagram shows: a first reflection point 110 as a filled point, the distance of which is determined based on the first echo signal in time of the corresponding received signal waveform; a second reflection point 120 as a double-shaded point, the distance of which is determined based on the second echo signal in time of the corresponding received signal waveform; a third reflection point 130 as a single-shaded point, the distance of which is determined based on the third echo signal in time of some received signal waveforms; and a fourth reflection point 140 as an unfilled point, the distance of which is determined based on the fourth echo signal in time of some received signal waveforms.

[0124] The reverse-parked vehicle 32 is essentially obscured. In other words, if only the first reflection point 110 is considered the primary reflection point, and the presence of secondary reflection points located behind them along the same axis within a predetermined maximum distance, such as 25 to 50 cm, and preferably about 35 cm, is examined to determine whether there is a high or low object height in the direction of the corresponding lateral axis 70, then the high object height, corresponding to parked vehicles 31 and 33, will be identified at the transmitting and receiving positions indicated as 41 and 45. Figure 12 The distance between the second reflection point 110 and the first reflection point 110 at the transmit and receive positions marked 42 and 44 is greater than the predetermined maximum distance, therefore... Figure 12 At the transmit and receive positions marked 42 and 44, low-height objects that can be driven through when parked will be incorrectly identified. Only at transmit and receive position 43, representing a reverse-parked vehicle 32, can a high-height object be correctly identified. However, if statistical methods are used to evaluate the obtained object height, this single (correct) measurement may be filtered out as an outlier, and parking spaces may be incorrectly identified based on the majority of incorrect measurements in areas 42, 43, and 44. In any case, this process will result in only seven correct measurement points having the correct object height determination (the reflection point is located along the lateral axis 70 at transmit and receive position 43, at the three transmit and receive positions 40 arranged on the far left, and at...). Figure 12 The symbol is 41, and at the rightmost transmit and receive position 40, in Figure 12 (represented as 45 in Chinese).

[0125] According to an exemplary embodiment, the positions of reflection points 110, 120, 130, and 140 are therefore measured by the third unit 23 in step S3 based on measurements from different received signal waveforms (reflection points 110, 120, 130, and 140).

[0126] According to a preferred variant of the exemplary embodiment, reflection points from adjacent received signal waveforms of the same order are measured trilaterally from each other in this case. The “order” of the reflection points should be understood here as referring to the corresponding echo signal waveforms ( Figure 5 The order of the corresponding echo signals in 10) of the reference, that is, their positions in chronological order. For example, according to the reference... Figure 8 The described method, based on the position or distance of one of the first reflection points 110 initially assumed on the transverse axis 70 at one of the adjacent transmit and receive positions 40, performs trilateration on the position of one of the first reflection points 110 initially assumed on the transverse axis 70 at one of the transmit and receive positions 40, thereby making it more accurate. However, other variations are also possible; reflection points from different sequences of received signal waveforms that are not directly adjacent can also be trilaterated with each other.

[0127] Figure 13 A two-dimensional diagram of a set of reflection points 100 formed by trilateration reflection points 110, 120, 130, and 140 according to an exemplary embodiment is shown. This produces a clearer image. The outlines of parked vehicles 31, 32, and 33 are arranged with two rows of reflection points 110, 120, 130, and 140, respectively. However, it should be noted that each of the first and third vehicles 31 and 33 has a row of first reflection points 110 and second reflection points 120 arranged behind it. On the other hand, the outline of the rear-parked vehicle 32, except for the center position, is arranged with two rows of higher-order reflection points.

[0128] refer to Figure 9 , Figure 10 , Figure 11 and Figure 13 In step S4, the fourth unit 24 forms multiple pairs of primary and secondary reflection points among the reflection points 110-140, which identify the reflection points as reflection points that are direct or indirect reflections from the same part of the same object from the objects 31, 32, 33 in the lateral environment 5 based on at least position criteria.

[0129] According to an exemplary embodiment, the fourth unit 24 can freely select pairs from the entire set of reflection points 100, and is particularly not limited to selecting reflection points only from the same echo signal waveform (in Figure 12 The reflection points are drawn on the same axis 70.

[0130] When a pair is formed, each reflection point 110-140 identified as a primary reflection point can be used only once to successfully form a pair; however, reflection points 110-140 that are considered secondary reflection points can be used multiple times as secondary reflection points.

[0131] This allows at least seven pairs of reflection point pairs, each consisting of a corresponding primary reflection point 110 and a corresponding nearest secondary reflection point 120, to be formed along the outline of vehicle 31 (its right half), although only five secondary reflection points 120 are identified in the outline region of vehicle 31.

[0132] At least nine pairs of reflection point pairs can be formed by primary reflection points 110, 120, 130 of the first, second, or third order and secondary reflection points 120, 230, 140 of the second, third, or fourth order, which are identified as being associated in the area of ​​the reverse-parked vehicle 32 according to a location-based criterion.

[0133] It should also be noted that Unit 42 does not necessarily require knowledge of the order of the reflection points. It is sufficient for the reflection points in the group of reflection points 100 that have been identified as primary or secondary reflection points to meet the location-based criteria.

[0134] For details regarding location-based standards and the principles for identifying pairs of reflection points, please refer to the reference above. Figure 6 The given description and the following references Figure 14 The given description.

[0135] In step S5, if the reflection points 110-140 in question are the primary reflection points of one of the formed reflection point pairs, the fifth unit 25 of the measuring device 6 determines the height of the object at the corresponding one of the reflection points of the set of reflection points 100 in the lateral environment 5 as high, and if no reflection point pair including the reflection points 110-140 in question as a primary or secondary reflection point is formed in step d), the height of the object is determined as low.

[0136] exist Figure 13 In the case shown, a total of 23 measurement points will be generated, each containing the position of a reflection point in the set of reflection points 100, at which the height of the tall object is correctly determined. Therefore, a significantly greater number of correct measurement points can be generated compared to not performing trilateration and only searching for double echoes within the same received signal waveform.

[0137] The set of reflection points 100 (measured in this way on three sides in the lateral environment 5 of vehicle 1) Figure 13After determining the object height at multiple reflection points, in the parking method of the exemplary embodiment, a parking space can then be determined in the lateral environment 5 where no object height is determined to be "high" at any reflection point; and the parking assistance system can park the vehicle 1 in the parking space. However, in Figures 11 to 13 In the case shown, no parking space will be correctly identified, therefore vehicle 1 cannot park here.

[0138] Figure 14 Details of a set of reflection points, including multiple reflection points 111-133, are shown to explain the criteria for forming pairs of reflection points according to a further exemplary embodiment.

[0139] In a further exemplary embodiment, in step S3, when a group of reflection points is formed in the group of reflection points 100, in addition to measuring the position of the reflection points using trilateration, one or more attributes are stored. These attributes are... Figure 14 The middle part is visualized as follows:

[0140] The first attribute is the order of the two echo signals, that is, their position relative to the corresponding received signal waveform. Figure 5 The position of the echo signal in the time sequence of 10) is used to perform trilateration on the reflection point. For easier understanding, for this description, it is assumed that each of the reflection points 111-133 is trilaterated using two echo signals in the same order. The first-order reflection points 111 and 112 are shown as filled points. The second-order reflection points 121 and 123 are shown as double-shaded points. The third-order reflection points 131, 132, and 133 are shown as single-shaded points.

[0141] Another attribute is signal strength, such as the average of the maximum amplitudes of the two echo signals, based on which trilaterations are performed at the corresponding reflection points 111-133. Signal strength in Figure 14 The diameter is represented by the diameter of one of the corresponding reflection points 111-133, where a larger diameter indicates a higher signal strength and a smaller diameter indicates a lower signal strength.

[0142] Another attribute involves information about the two received signal waveforms, based on which trilaterations are performed on the corresponding reflection points 111-133, particularly the transmission and reception positions of the corresponding received signal waveforms. Figure 5 10). Figure 14The Roman numerals used indicate an attribute associated with the identity of the received signal waveforms to be measured in trilateration. In this case, Roman numeral "I" represents the first pair of received signal waveforms, Roman numeral "II" represents the second pair, and Roman numeral "III" represents the third pair. The relevant transmit and receive positions can be determined based on the identity of the received signal waveforms, for example, by looking them up in a table created by the first unit.

[0143] Figure 14 The theoretically expected locations of other reflection points at 122 and 113 are also shown. Therefore, in the second pair II formed by the received signal waveforms, the second sequential reflection point with average signal strength is actually expected at 122. However, in this example, due to noise, a suboptimally chosen threshold, etc., the associated echo signal is not identified. As a result, reflection point 132, which should be the third sequential reflection point in terms of its signal strength, is identified as the second sequential reflection point. Similarly, the first sequential reflection point with high signal strength at 113 is actually expected in the third pair III formed by the received signal waveforms. However, the associated echo signal is not identified. Therefore, reflection point 123, which should be the second sequential reflection point in terms of its signal strength, may be incorrectly identified as the first sequential reflection point, and reflection point 133, which should actually be the third sequential reflection point in terms of its signal strength, may be incorrectly identified as the second sequential reflection point.

[0144] The following discusses possible location-based and other criteria, assuming the first sequential reflection points 111 and 112 are primary reflection points, how to determine the relevant secondary reflection points, and how to generate meaningful measurement points (determination of object height and related positions). The criteria discussed below are step S4 ( Figure 9 Examples of "at least location-based criteria" in ().

[0145] Figure 14 Specifically, for each of the principal reflection points 111 and 112, geometric search windows 91 and 92 are defined, which are aligned with the lateral direction 20, are its mirror image, and are located from the principal reflection points 111 and 112 in the lateral direction (i.e., away from them). Figures 11 to 13 The transmitting and receiving positions 40 in the middle extend laterally, that is, in the lateral direction 18.

[0146] According to an exemplary embodiment, one criterion is the fact that secondary reflection points 121, 123 must be within geometric search windows 91, 92. The fact that the geometric search window is shaped as a segment of a circle with vertices of primary reflection points 111, 112 prevents the two primary reflection points 111, 112 from being incorrectly identified as a pair of reflection points formed by direct and indirect reflections in a purely position-based determination of the reflection point pair.

[0147] The radius of the geometric search window 91, 92, which selects a segment of the circle based on the predetermined maximum distance, also ensures that the distance between the primary reflection points 112, 112 and the secondary reflection points 121, 123 is less than the predetermined maximum distance.

[0148] It should be noted that the second geometric search window 92 defined by the main reflection point 112 is the first sequential reflection point from the second pair of II received signal waveforms. Although it does not have a second sequential reflection point from the second pair of II received signal waveforms, it has two second sequential reflection points from other received signal waveforms, namely reflection point 121 from the first pair of I received signal waveforms and reflection point 123 from the third pair of III received signal waveforms.

[0149] According to an exemplary embodiment, when there are more than one reflection point 121, 123 in the geometric search window 92, the reflection point 123 closest to the primary reflection point 112 is selected as the secondary reflection point of the pair to be formed.

[0150] According to an exemplary embodiment, one criterion is the fact that only pairs of reflection points with different orders, particularly those with an order difference of only one, are combined with each other. Therefore, when the difference is one, the order of the echo signals can be combined to form pairs. Thus, reflection point 112 can be combined with reflection point 121, but not with reflection point 123. In a variant that does not use geometric search windows 91, 92, according to this exemplary embodiment, the pair formed by the first primary reflection point 112 and the third reflection point 133 can also be prevented, and this may thereby obscure the pair formed by the third reflection point 133 and another fourth reflection point (not shown) located behind it, which has the same received signal waveform.

[0151] According to an exemplary embodiment, one criterion is the fact that the secondary reflection point to be selected is farther away from the transmission and reception points of the echo signals associated with the primary reflection points 111 and 112 than the primary reflection point. Figures 11 to 13 (40 in the middle). Figure 14 In this case, the standard is always satisfied for the principal reflection points 111 and 112.

[0152] According to an exemplary embodiment, one criterion is the fact that the signal strength stored as an attribute of a potential secondary reflection point is reduced by no more than a predetermined factor compared to the signal strength stored as an attribute of a potential primary reflection point. In other words, the signal strength of a secondary reflection point must not be greater than the signal strength of a primary reflection point, and must not be less than the signal strength of a primary reflection point by more than a predetermined factor. The predetermined factor can be empirically selected based on typical signal strength relationships. For example, in… Figure 14In this context, this standard can be used to prevent incorrect combinations of the primary first-order reflection point 112 and the third-order reflection point 132, even if, for example, information about the order of reflection points 111-133 is unavailable and geometric search windows 91, 92 are not used.

[0153] Based on the location-based criteria and other criteria described above, it has become clear that although no reflection point is identified for reflection point 112 at 122, a pair of reflection points can be formed together with reflection point 121 or reflection point 123, and thus additional meaningful measurement points can be obtained.

[0154] It should be particularly noted that the reflection point selected as a secondary reflection point can preferably also be used as a secondary reflection point in another pair of reflection points, but preferably cannot be used as the primary reflection point in another pair of reflection points. Therefore, in Figure 14 In one exemplary embodiment, the first pair of reflection points may be formed by reflection points 111 and 121, and the second pair of reflection points may be formed by reflection points 112 and 121. Therefore, meaningful measurement points can be advantageously obtained at the locations of the primary reflection point 111 and the primary reflection point 112.

[0155] On the other hand, if a pair of reflection points 112 and 123 are formed in an exemplary embodiment, then in an exemplary embodiment, another pair of reflection points 123 and 133 cannot be formed thereafter.

[0156] This advantageously prevents the erroneous acquisition of meaningless measurement points at the location of reflection point 123, which is identified as the first sequential reflection point but actually represents an indirect reflection of the reflection point at 113, which was not identified due to noise, etc.

[0157] The above criteria can be combined with each other in an appropriate manner, such as logically and / or probabilistically.

[0158] Although the invention has been described based on exemplary embodiments, it can be modified in many ways.

[0159] Figure 1 and 11 The measuring device 6 is shown as part of the parking assistance system 3. However, alternatively, the measuring device 6 can also be arranged separately in the vehicle 1. The measuring device 6 can also be integrated with the ultrasonic transceiver 4 to form a unit.

[0160] The proposed teaching has been described based on simplified assumptions that when transmitting the signal and throughout the reception of the received signal waveform, vehicle 1 and ultrasonic transceiver 4 are located at the same transmitting and receiving position, then continue to the next transmitting and receiving position, where another stationary transmission and reception is performed. However, it goes without saying that vehicle 1 can preferably travel at a uniform speed along the lateral direction 18. In this case, the transmitting position of the transmitted signal differs from the corresponding receiving position of the corresponding echo signal in the received echo signal waveform. The corresponding modifications to the geometric, trigonometric, or mathematical observations disclosed herein will not be difficult for those skilled in the art.

[0161] Figure 14 A corresponding defined geometric search window 91, 92 in the main reflection points 111, 112 is shown aligned with and mirrored in the lateral direction 20, and extends laterally in the lateral direction 18. However, this shape of the geometric search window is just one of many possible examples. If the identity of one or more corresponding received signal waveforms is stored as an attribute in the set of reflections 100, the corresponding geometric search windows 91, 92 can also be aligned with and mirrored in a straight line corresponding to the transmission and reception positions of one of the received signal waveforms. Figure 11-13 The geometric search windows 91 and 92 intersect with the main reflection points 111 and 112. The geometric search windows 91 and 92 can also have other shapes that are not segments of a circle, such as squares or rectangles. The geometric search windows 91 and 92 defined for the corresponding main reflection points 111 and 112 do not necessarily contain the main reflection points 111 and 112, and in particular, a specific lateral distance to the main reflection points 111 and 112 can be maintained to avoid two too close reflection points from two different received signal waveforms being incorrectly identified as a pair of reflection points or double echoes.

[0162] List of reference numerals

[0163] 1, 1' vehicle

[0164] 2 Environment

[0165] 3 Parking Assist System

[0166] 4. 4' Ultrasonic Transceiver

[0167] 5 Lateral Environment

[0168] 6. Measuring device

[0169] 7. Horizontal axis

[0170] 8. Horizontal profile of transmitted signal strength

[0171] 9. Vertical profile of transmitted signal strength

[0172] 10. Received signal waveform

[0173] 11 Other parked vehicles

[0174] 12 First point, first reflection point

[0175] 13 Second point

[0176] 14. Third point

[0177] 15 Ground

[0178] 16 virtual reflection points, second reflection points

[0179] 17 Roadside

[0180] 18 Lateral direction

[0181] 19, 19' circle

[0182] 20. Horizontal direction

[0183] Units 1-6, 21-26

[0184] 31-33 Obstacles, objects, parked vehicles

[0185] 40. Transmit and receive positions

[0186] 41-45 Transmit and receive positions

[0187] 70 Horizontal axis

[0188] 91, 92 Geometric Search Window

[0189] 100 grouped reflection points

[0190] 110 First Sequence Reflection Point

[0191] 111 First Sequence Reflection Point

[0192] 112 First Sequence Reflection Point

[0193] 113 Unidentified First Sequence Reflection Point

[0194] 120 Second Sequence Reflection Point

[0195] 121 Second Sequence Reflection Point

[0196] 122 Unidentified Second Sequence Reflection Points

[0197] 123 was identified as the second-order reflection point of the first-order reflection point.

[0198] 130 Third Sequence Reflection Point

[0199] 131 Third Sequence Reflection Point

[0200] 132 was identified as the third-order reflection point of the second-order reflection point.

[0201] 140 Fourth Sequence Reflection Point

[0202] t0-t6 time

[0203] d, d' distance

[0204] V th threshold

[0205] S1-S6 Method Steps

Claims

1. A method for measuring the lateral environment (5) of a vehicle (1) equipped with at least one lateral ultrasonic transceiver (4), comprising the steps of: Step a: Activate at least one ultrasonic transceiver (4) at a plurality of transmitting and receiving positions (40) along the lateral driving direction (18) of the vehicle (1) to transmit a corresponding transmitting signal in the lateral direction (20) to the lateral direction (18) of the vehicle (1) and receive a corresponding receiving signal waveform (10) reflected from the lateral environment. Step b: Identify multiple echo signals in the corresponding received signal waveform (10); Step c: A set of reflection points (100) is formed by performing multiple trilaterations on the corresponding reflection points (110, 120, 130, 140) in the lateral environment (5) based on two corresponding received signal waveforms from multiple received signal waveforms (10) and the corresponding echo signals from each of the two received signal waveforms (10), and stored in the set of reflection points (100); Step d: Form multiple pairs of reflection points (100) consisting of corresponding primary reflection points (111, 112) and corresponding secondary reflection points (121, 123), which are identified as direct and / or indirect reflections from the same object portion (31, 32, 33) in the lateral environment (5) based on at least position-based criteria, wherein the secondary reflection points are virtual reflection points, and wherein the primary and secondary reflection points of any pair of formed reflection points can include reflection points measured using echo signals from different received signal waveforms; and Step e: If the reflection point in question is the primary reflection point (111, 112) of one of the pairs of reflection points formed, then the object height at the corresponding one of the reflection points (110, 120, 130, 140) in the lateral environment is determined to be high, and if no pair of reflection points including the reflection point in question as a primary or secondary reflection point is formed in step d, then it is determined to be low.

2. The method as described in claim 1, characterized in that, The criteria in step e include the fact that the corresponding secondary reflection points (121, 123) are arranged within the geometric search window (91, 92) defined relative to the corresponding primary reflection points (111, 112).

3. The method as described in claim 2, characterized in that, The geometric search window (92) includes at least one reflection point (121, 123) that has been trilated based on two corresponding echo signals identified in the received signal waveform, rather than the two echo signals that have been trilated based on the main reflection point (112).

4. The method as described in claim 2, characterized in that, As the distance to the main reflection points (111, 112) increases, the geometric search window (91, 92) widens laterally in the horizontal direction.

5. The method as described in any one of the preceding claims, characterized in that, Among a plurality of reflection points (121, 123) that meet the criteria for the corresponding primary reflection point (112), the reflection point (123) closest to the primary reflection point (112) is selected as the secondary reflection point in the pair of emission points to be formed.

6. The method according to any one of claims 1 to 4, characterized in that, The echo signals identified in the corresponding received signal waveform (10) are sorted according to their time order, and in step c, echo signals from the echo signal waveforms (10) received at adjacent receiving positions in the same order are used to perform trilateration on the corresponding reflection points (110, 120, 130, 140).

7. The method as described in claim 6, characterized in that, The criteria in step e include the fact that the order of the echo signals based on the trilateration of the secondary reflection point (121) is one higher than the order of the echo signals based on the trilateration of the primary reflection points (111, 112).

8. The method according to any one of claims 1 to 4, characterized in that, The criteria in step e include the fact that the secondary reflection points (121, 123, 132, 131, 133) are farther away from the transmission and reception points of the echo signals associated with the primary reflection points (111, 112) than the primary reflection points (111, 112).

9. The method according to any one of claims 1 to 4, characterized in that, The criteria in step e include the fact that the distance between the primary reflection points (111, 112) and the secondary reflection points (121, 123) is less than a predetermined maximum distance.

10. The method according to any one of claims 1 to 4, characterized in that, The criteria in step e include the fact that the signal strength of at least one echo signal measured based on the trilateration of the primary reflection points (111, 112) is reduced by no more than a predetermined factor compared to the signal strength of at least one echo signal measured based on the trilateration of the primary reflection points (121, 123).

11. The method according to any one of claims 1 to 4, characterized in that, The trilateration positions of the corresponding reflection points (111-133) and one or more optional attributes are stored in the group of reflection points (100) of the reflection points (111-133), and steps d and e are performed after steps a, b) and c are completed based on the storage positions stored in the group of reflection points (100) and the storage attributes of the reflection points (111-133) when applicable.

12. A method for parking a vehicle (1), the vehicle being equipped with at least one lateral ultrasonic transceiver (4) and a parking assistance system (3), the method comprising: Perform the method as described in any one of claims 1 to 11 to determine the position and object height at a plurality of principal reflection points (110, 120, 130) in the lateral environment (5) of the vehicle (1); Determine the parking space in which no object height is determined as "high" in the lateral environment (5); as well as Use the parking assistance system (3) to park the vehicle (1) in the parking space.

13. A computer program product comprising instructions that, when executed by a computer device, cause the computer device to perform the method as described in any one of claims 1 to 12.

14. A measuring device (6) for a parking assistance system (3) of a vehicle (1) equipped with at least one lateral ultrasonic transceiver (4), wherein the measuring device (6) is configured to measure the lateral environment (5) of the vehicle (6), and comprises: a) A first unit (21) configured to activate at least one ultrasonic transceiver (4) at a plurality of transmitting and receiving positions (40) along the lateral driving direction (18) of the vehicle (1) to transmit a corresponding transmitting signal in the lateral direction (20) of the vehicle (1) in the lateral direction (18) and to receive a corresponding receiving signal waveform (10) reflected from the lateral environment. b) The second unit (22) is configured to identify multiple echo signals in the corresponding received signal waveform (10); c) The third unit (23) is configured to form a set of reflection points (100) by performing multiple trilaterations on the corresponding reflection points (110, 120, 130, 140) in the lateral environment (5) based on two corresponding received signal waveforms from a plurality of received signal waveforms (10) and based on the corresponding echo signal from each of the two received signal waveforms (10), and store the set of reflection points (100); d) A fourth unit (24) configured to form multiple pairs of corresponding primary reflection points (111, 112) and corresponding secondary reflection points (121, 123) in the set of reflection points (100), which are identified, based at least on a position-based criterion, as reflection points of direct and / or indirect reflection from the same object portion (31, 32, 33) in the lateral environment (5), wherein the secondary reflection points are virtual reflection points, and wherein the primary and secondary reflection points of any pair of formed reflection points can include reflection points for trilateration using echo signals from different received signal waveforms; and e) Unit 5 (25) is configured such that if the reflection point under discussion is the primary reflection point (111, 112) of one of the pairs of reflection points formed, the height of the object at the corresponding one of the reflection points (110, 120, 130, 140) in the lateral environment is determined to be high, and if no pair of reflection points including the reflection point under discussion as a primary or secondary reflection point is formed in Unit 4 (24), it is determined to be low.

15. A vehicle (1) including a parking assistance system (3) configured for semi-autonomous or fully autonomous driving of the vehicle (1), wherein the vehicle (1) and / or the parking assistance system (3) includes the measuring device (6) as claimed in claim 14.

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