Multi-channel ultrasonic measurement unit and corresponding method and computer program product

Abstract

The invention relates to an ultrasonic measuring unit, in particular for use in a vehicle, comprising a control unit and an analysis unit, the control unit being designed to control an ultrasonic transducer for emitting ultrasonic signals alternately in different channels, and the analysis unit being designed to analyze the echoes resulting from the ultrasonic signals in the channels in order to detect at least one object causing the echoes.

Description

[Technical Field]

[0001] The invention relates to an ultrasonic measuring unit, a method of operating an ultrasonic measuring unit, and a corresponding computer program product, particularly for use in a vehicle. Summary of the Invention

[0002] Motorized vehicles are increasingly being equipped with ultrasonic sensors, usually integrated into the vehicle body, intended to assist the driver in detecting obstacles in the path of the motorized vehicle in time and in assessing the distance from the obstacles, especially in areas where the driver's visibility is poor. The operating principle of such ultrasonic sensors is based on emitting an ultrasonic signal and detecting echoes of the emitted ultrasonic signal, which echoes originate from any obstacles within the sensor's detection range. The ultrasonic pulses generated for this purpose can have a frequency that is constant in time. Furthermore, approaches using a frequency that is variable in time ("chirp") and multiple separate emission and reception channels (e.g., frequency division multiplexing) are known.

[0003] Ultrasonic sensors are used today in a wide range of applications, from parking assistance to assistance systems for blind spot detection. In the field of autonomous driving in urban environments ("urban driving"), ultrasonic sensors have so far been used very little. This is due, on the one hand, to the desire for higher performance systems, especially in partially or fully automated driving, and, on the other hand, to the limited range of ultrasonic sensors in combination with their sampling rate, which is limited by the speed of sound.

[0004] The speed of sound strongly determines the range and sampling rate of ultrasonic sensors. As a result, in the automotive field, ranges of up to 10 m using ultrasonic sensors are already conceivable today. Due to the speed of sound, such a measurement using an ultrasonic sensor takes as long as 60 ms under normal conditions. In the best case, 16 measurements per second are possible. Currently, when multiple sensors are used in a system and multiple measurement steps are required to achieve full system coverage, the measurement rate for the complete system typically drops to 5 to 8 updates per second. Such low update rates have significant negative effects on object detection, especially object tracking, and for this reason are currently unusable.

[0005] The object of the invention is to provide an improved ultrasonic measuring unit, together with a corresponding method and computer program product. The underlying problem of the invention is solved by the features of the independent claims. Embodiments are described in the dependent claims.

[0006] To achieve this object, the invention provides an ultrasonic measurement unit, in particular for use in a vehicle, comprising a control unit and an analysis unit, - the control unit is designed to control the ultrasonic transducer to emit ultrasonic signals alternately on different channels; - the analysis unit is designed to analyze the echoes resulting from the ultrasonic signals in the channel in order to detect at least one object causing the echoes;

[0007] According to the invention, the ultrasonic measurement unit alternately emits ultrasonic signals, e.g., ultrasonic pulses, on two or more different channels. In this case, the term "channel" refers to any characteristic of the ultrasonic signal based on which the analysis unit can distinguish an echo of a first ultrasonic signal emitted on a first channel of the two or more different channels from an echo of a second ultrasonic signal emitted on another second channel of the two or more different channels. Without being limited thereto, such channel-defining characteristics may include a characteristic frequency, a characteristic frequency spectrum, a characteristic time-frequency curve, a characteristic amplitude and / or a characteristic phase angle at the start of the emission operation of each ultrasonic signal.

[0008] The ultrasonic measurement unit may use one or more ultrasonic transducers for emission and reception. Multiple ultrasonic transducers may be used to emit ultrasonic signals, with at least two ultrasonic signals alternately emitted on different channels of each ultrasonic transducer used for emission. For example, the emitting ultrasonic transducer may be specifically designed for the two or more channels implemented. Using the same ultrasonic transducer to emit on different channels allows for highly efficient obstacle detection with minimal technical effort and material usage. In this case, obstacle detection can be performed at a high sampling rate.

[0009] In principle, some or all of the echoes to be processed by the analysis unit can be received by the same ultrasonic transducer from which the respective original signals of the echoes were emitted. This can also reduce the technical effort and material use required for using multi-channel ultrasound for obstacle detection. However, it is also possible to use one or more additional ultrasonic transducers to receive echoes of the ultrasonic signals emitted by the emitting ultrasonic transducers. Preferably, some or all of the ultrasonic transducers are capable of emitting and receiving on all implemented channels. However, the available ultrasonic sensors can alternatively be divided into those that emit and / or receive on only some of the channels and those that emit and / or receive on only another part of the channels. In particular, each of the receiving ultrasonic transducers can be assigned to one or more of the channels or designed to receive on one or more of the channels. The ultrasonic transducers specific to one or more channels can differ from each other in terms of design so that each can better meet the specific requirements of the channels implemented on each ultrasonic transducer. For example, different frequency ranges correspond to these channels, and ultrasound transducers operating in different frequency ranges can be optimized accordingly for maximum efficiency in terms of transduction in each frequency range.

[0010] It is also possible to use ultrasonic transducers that are specifically designed to emit ultrasonic signals and receive echoes that have smaller amplitudes than the original ultrasonic signal underlying the echoes. The emitting and receiving transducers can differ from each other in design to better meet the specific requirements of each individually emitting and receiving. For example, the emitting ultrasonic transducer can be designed to generate ultrasonic signals with large amplitudes with as little distortion as possible, while the receiving ultrasonic transducer can be designed to detect echoes of the ultrasonic signal with as high sensitivity as possible in a low-noise manner.

[0011] The control unit and the analysis unit may be implemented as different units or assemblies that operate independently of each other in terms of signal transmission. Alternatively, the control unit and the analysis unit may be integrated into the same assembly or unit. For example, the control unit and the analysis unit may be realized by analog or digital electronics, in particular in the form of one or more integrated circuits. The control unit and the analysis unit may also be implemented as software modules executed by a general-purpose or specialized processor, in particular a central processing unit (CPU). One or more communication channels may be implemented between the control unit and the analysis unit, which enable the transmission of signals between the two units beyond the emission of ultrasound signals and the reception of echoes of these emitted ultrasound signals.

[0012] Preferably, the control unit controls the ultrasonic transducer by outputting an electrical signal. The ultrasonic transducer may be designed to convert between electrical energy and mechanical vibrations. For example, the ultrasonic transducer may have a membrane that is excited by a piezoelectric element to emit an ultrasonic signal, or that is set to acoustic vibrations when receiving an ultrasonic signal and transmits the latter to the piezoelectric element. The electrical signal output by the piezoelectric element and corresponding to the received ultrasonic signal may then be received and analyzed by the analysis unit.

[0013] According to one embodiment, the control and analysis are performed in a measurement cycle, which is periodically repeated. In particular, changes in the distance between the emitting ultrasonic transducer and an obstacle can be detected. As will be explained in detail below, the alternate emission of ultrasonic signals on different channels can not only effectively increase the detection rate for obstacles, but also enable quasi-simultaneous measurement of multiple distance ranges (e.g., a near range of up to 5 m and a far range of 5-10 m) with a high or optimized sampling rate for the near range. In particular, the periodic repetition of the measurement cycle can allow echoes to be received from ultrasonic signals emitted in the previous measurement cycle. In this way, continuous detection of obstacles within the detection range, for example, at a high sampling rate, is possible.

[0014] According to one embodiment, within a measurement period, the ultrasonic signals include at least a first ultrasonic signal on a first channel and a second ultrasonic signal on a second channel. Thus, the ultrasonic measuring unit first emits the first ultrasonic signal on the first channel. Then, during a first predetermined receiving period, the ultrasonic measuring unit can receive echoes resulting from the first ultrasonic signal. Because the echoes received during this first receiving period are temporally close to the emission of the first ultrasonic signal, they are due to reflections from obstacles in the "near range" of the ultrasonic transducer.

[0015] After the first receiving period, but still always at the same measurement period, the ultrasonic measuring unit emits a second ultrasonic signal on a second channel, where the second channel is different from the first channel. Thereafter, during a second predetermined receiving period, the ultrasonic measuring unit can receive echoes of the second ultrasonic signal, again originating from the near range but received on the second channel.

[0016] According to one embodiment, the analysis considers at least echoes occurring in the first channel between the emission of the two ultrasonic signals, and the analysis considers echoes occurring in the first and second channels after the emission of the second ultrasonic signal. Thus, within the second reception period, the ultrasonic measuring unit can additionally receive, in the first channel, echoes of the first ultrasonic signal previously emitted in the first channel. Since the echoes received during the second reception period have already propagated over the duration of the first reception period and the duration of the emission of the second ultrasonic signal, they provide information about obstacles that scatter the first ultrasonic signal back to the ultrasonic transducer connected to the ultrasonic measuring unit from a greater distance corresponding to this longer propagation duration.

[0017] In this way, considering the entire measurement period, it is possible to detect obstacles in the near and far ranges using individual emitting ultrasonic transducers within the measurement period, for example the sampling rate in the near range is twice that for the far range. In this way, in addition to the two measurements in the near range, a measurement in the far range can also be performed in the second reception period without limiting the repetition rate.

[0018] For example, an ultrasonic measurement unit may be designed for simultaneous reception of echoes of an ultrasonic signal on at least two channels (the aforementioned channels), with as little pause between two measurements as possible and with the measurement times accurately known. This may be particularly advantageous if the channels have low "coupling," i.e., if the emission of a second ultrasonic signal on the second channel does not affect the reception of echoes on the first channel. In this case, the ultrasonic measurement unit may continue to receive echoes of the first ultrasonic signal on the first channel even while emitting the second ultrasonic signal, and there is no "blind area" between echoes from the near range and echoes from the far range. Such a blind area corresponds to a spatial region ("blind spot") in which no obstacles can be detected.

[0019] The above example illustrates the basic concept of the invention based on ultrasonic signals transmitted and received on two channels. However, the ultrasonic measurement unit may also emit more than two ultrasonic signals on more than two different channels and be designed to receive echoes of the ultrasonic signals emitted on those channels. In this way, the spatial detection range of the ultrasonic measurement unit may be divided into more than two distance ranges. For example, in the case of a three-channel ultrasonic measurement unit, there may be a near range, from which echoes of ultrasonic signals are received on all three channels within a single measurement period. There may also be an average distance range, from which echoes are received on the first two channels within the same measurement period. Finally, there may also be a far range, from which only echoes of the earliest emitted first ultrasonic signal are received on the first channel within the same measurement period. The concept can easily be transferred to any other number of channels per measurement period.

[0020] According to one embodiment, a maximum spatial measurement range for the ultrasonic measurement unit is defined, and the length of the measurement period is set so that an echo resulting from a first ultrasonic signal and resulting from reflection from an object located at the maximum measurement range can be detected within the measurement period. The maximum spatial measurement range (herein referred to as range) is the maximum distance within which a detectable obstacle can be located. Therefore, the echo resulting from this most distant obstacle can be detected during the measurement period. It results from the ultrasonic signal emitted earliest during this measurement period.

[0021] JPEG2025541703000002.jpg48162

[0022] In the case of alternating emission on N channels, the period duration is divided into T / N subintervals, each subinterval having an emission period for emitting on one of the N channels and a reception period for receiving echoes. Echoes of an ultrasonic signal received in a second or subsequent subinterval after an ultrasonic signal emitted in a previous subinterval can be measured over a period of T / N for the multi-channel ultrasonic measurement unit disclosed herein without having to worry about measurement rate limitations for near range. 1K =T 2K This can provide a greater range (eg, double the range when using two channels) compared to a single channel ultrasound measurement unit with / N.

[0023] Same period duration T 1K =T 2K It should be noted that, compared to a single-channel ultrasonic measurement unit having a range, the multi-channel ultrasonic measurement unit disclosed herein can monitor a closer section (distance range) of the detection range defined by its range, i.e., the near range, at a higher sampling rate than a farther section (distance range) of the detection range (e.g., the far range). This is because the ultrasonic measurement unit does not need to wait until the start of a new measurement cycle before sending out a new ultrasonic signal that enables monitoring of the near range. Instead, it can emit ultrasonic signals on other channels to utilize the delay time of echoes from the far range to achieve higher frequency monitoring of the near range.

[0024] For simplicity and without limitation, a two-channel ultrasonic measurement unit is preferably used as an example. This means that it can detect objects in the near field and identify objects in the far field early. This can lead to applications, particularly in urban areas. For example, an ultrasonic measurement unit can be used in a motor vehicle to check whether a turning lane is blocked. The wider range of the ultrasonic measurement unit can enable this function even if the turning lane is more than one lane away from the currently used lane. The high sampling rate enabled by the invention is particularly relevant for the near field. Here, short-term changes in the distance to an obstacle can have a greater impact, involving greater risk, than for the far field.

[0025] According to one embodiment, the analysis unit is designed to analyze echoes resulting from the ultrasonic signal continuously on all channels within a measurement period. In this way, the analysis unit can analyze echoes (from previous measurement periods) at any time during a repetition of a measurement period on a given channel, especially during "early" reception periods. In this way, more distant ranges within the range of the ultrasonic measurement unit can be continuously monitored at the same measurement rate as ranges closer to the emitting ultrasonic transducer. The delay time of an echo received on a given channel before it is emitted again can be reconstructed from the reception time and the characteristics of the channel on which the echo was received, provided that the emission method is known (i.e., the subinterval in which the given measurement period is performed and the channel on which the emission is performed).

[0026] According to one embodiment, the analysis unit is designed to receive echoes from the same ultrasonic transducer from which the ultrasonic signal is emitted. Therefore, it may be sufficient to equip the ultrasonic measurement unit with a single ultrasonic transducer, as opposed to an ultrasonic measurement unit with different transducers for emission and reception. As a result, a simpler design of the ultrasonic measurement unit may be realized, using less material.

[0027] According to one embodiment, the different channels include at least three channels, and within a measurement period, the emission of successive ultrasonic signals occurs at different time intervals, with the different time intervals being constant for the periodically repeated execution of the measurement period. Within a given first measurement period, the successive ultrasonic signals emitted from a first pair of channels are emitted at a time interval t1. This time interval t1 is different from the time interval t2 for the successive ultrasonic signals emitted from a different second pair of channels within the same measurement period. The condition that the different time intervals for the periodically repeated execution of the measurement period are constant means that, in another second measurement period, the ultrasonic signals emitted from the first pair of channels are emitted at the same time intervals as previously corresponding to the first measurement period. As a result, the spatial region of the above-mentioned "blind spot" can be minimized or eliminated.

[0028] During the emission of an ultrasonic signal, it may happen that the analysis unit is unable to detect the echo of a first ultrasonic signal during a second emission period in which a second ultrasonic signal is emitted following the first ultrasonic signal ("blind area, blind spot"). Due to reverberation in the membrane of the ultrasonic transducer, the detection ability of this same transducer may be reduced or prevented during the emission and, if necessary, thereafter. Therefore, the duration of the actual "emission period" of an ultrasonic signal may extend significantly beyond the duration of the actual control signal that triggers the excitation force, for example, due to reverberation in the ultrasonic transducer after the excitation force has ceased.

[0029] As already explained above, the use of at least three channels with alternating emission allows a time division of a measurement period into at least three corresponding subintervals and a corresponding division of the spatial detection range of an obstacle into at least three distance ranges corresponding to the time subintervals. Thus, varying the time interval between two emission operations from one measurement period to the next allows an overall reduction in the size of the undetectable "blind" distance range at the transition between two adjacent distance ranges.

[0030] According to one embodiment, during the periodically repeated execution of the measurement periods, the emission of successive ultrasonic signals occurs at different time intervals for at least some of the measurement periods. Thus, for example, if the time at which a second ultrasonic signal is emitted in each of two measurement periods is varied by a time difference of +Δt or −Δt, the ultrasonic transducer can receive additional echoes of the ultrasonic signal in one of the measurement periods, even during the period Δt during which a new ultrasonic signal would otherwise have been emitted. Compared to dividing the measurement period into equally long subintervals, this reduces the area of ​​any "blind spots." For example, the relative variation in the time intervals for a given pair of channels used to emit successive ultrasonic signals in different measurement periods is at least 3%, preferably at least 5%.

[0031] According to one embodiment, the ultrasonic measurement unit further comprises an ultrasonic transducer, which is designed to receive echoes resulting from the ultrasonic signals in all channels and to send them to the analysis unit. This does not exclude that the ultrasonic measurement unit can have multiple ultrasonic transducers. If the ultrasonic measurement unit has multiple ultrasonic transducers, it consequently implies that the echoes detected by a given ultrasonic transducer do not necessarily have to originate from ultrasonic signals emitted by the same ultrasonic transducer.

[0032] In a further aspect, the invention provides a method of operating an ultrasonic measurement unit, particularly for use in a vehicle, the ultrasonic measurement unit comprising a control unit and an analysis unit, the method comprising: - controlling, by the control unit, the ultrasonic transducers to emit ultrasonic signals alternately on different channels; - analyzing, by an analysis unit, echoes resulting from the ultrasonic signals in the channels in order to detect at least one object causing the echoes.

[0033] In a further aspect, the invention provides a computer program product, in particular a computer-readable storage medium, the computer program product comprising computer-executable code, the code being executable by at least one processor of a computing device to cause the computing device to perform the methods disclosed herein.

[0034] Those skilled in the art will appreciate that aspects of the present invention may be embodied as an apparatus, a method, or a 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 generally referred to herein as a "circuit," "module," or "system." Furthermore, aspects of the present invention may take the form of a computer program product carried by a computer-readable medium or multiple computer-readable mediums in the form of computer-executable code. A computer program similarly includes computer-executable code. "Computer-executable code" may also be referred to as "computer program instructions."

[0035] 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. As used herein, a "computer-readable storage medium" includes a material storage medium capable of storing instructions executable by a processor of a computing device. The computer-readable storage medium may also be referred to as a computer-readable non-volatile storage medium. The computer-readable storage medium may also be referred to as a tangible computer-readable medium. In some embodiments, the computer-readable storage medium may also store data that allows it to be accessed by the processor of a 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, a flash memory, a USB key, a random-access memory (RAM), a read-only memory (ROM), an optical disk, a magneto-optical disk, and a processor register file. Examples of optical disks include compact disks (CDs) and digital versatile disks (DVDs), such as CD-ROM disks, CD-RW disks, CD-R disks, DVD-ROM disks, DVD-RW disks, or DVD-R disks. The term computer-readable storage medium also refers to various types of storage medium suitable for retrieval from a computer device via a network or communications connection. For example, data may be retrieved via a modem, the Internet, or a local network. Computer-executable code embodied in a computer-readable storage medium may be transmitted via any suitable medium, including, but not limited to, wireless, wired, fiber optic cable, RF, or the like, or any suitable combination of the above media.

[0036] A computer-readable signal medium may include a propagated data signal containing computer-readable program code, for example, in a fundamental signal (baseband) or as part of a carrier wave signal (carrier wave). Such a propagated signal may take any form, including, but not limited to, electromagnetic, optical, or any suitable combination thereof. A computer-readable signal medium may be any computer-readable medium that is not a computer-readable storage medium, but which can transmit, distribute, or carry a program for use by or in connection with a system, apparatus, or device for executing instructions.

[0037] "Computer memory" or "memory" is an example of a computer-readable storage medium. Computer memory is any memory that is directly accessible to a processor.

[0038] A "computer data store" or "data store" is another example of a computer-readable storage medium. A computer data store is any non-volatile computer-readable storage medium. In some embodiments, computer memory may be a computer data store, or vice versa.

[0039] As used herein, "processor" includes an electronic component capable of executing program-executable instructions or machine-executable instructions or computer-executable code. References to a computing device including "processor" should be interpreted as potentially including multiple processors or processing cores. A processor may be, for example, a multi-core processor. A processor may also refer to a collection of processors within a single computing system or a collection of processors distributed across multiple computing systems. The terms computing device or computer should also be interpreted as potentially referring to a collection or network of computing devices or computers, each containing one processor or multiple processors. Computer-executable code may be executed by multiple processors, which may be distributed within the same computing device or across multiple computers.

[0040] Computer-executable code may include machine-executable instructions or programs that cause a processor to perform an aspect of the invention. Computer-executable code for carrying out operations for aspects of the invention may be written in any combination of one or more programming languages, including object-oriented programming languages ​​such as Java, Smalltalk, C++, and conventional method-oriented programming languages ​​such as the programming language "C" or similar programming languages, and may be translated into machine-executable instructions. In some cases, the computer-executable code may be in the form of a higher-level programming language or may be in a pre-interpreted form and used in conjunction with an interpreter to generate the machine-executable instructions.

[0041] The computer executable code may run entirely on the user's computer as a stand-alone software package, partially on the user's computer, partially on the user's computer and partially on a remote computer, or entirely on a remote computer or server. In the latter case, the remote computer may be connected to the user's computer by any type of network, including a local area network (LAN) or a wide area network (WAN), or may be connected to an external computer (e.g., via the Internet using an Internet Service Provider).

[0042] The computer program instructions may be executed on one processor or on multiple processors. In the case of multiple processors, these may be distributed across multiple different entities (e.g., clients, servers, etc.). Each processor may execute a portion of the instructions intended for the respective entity. Thus, when a system or method including multiple entities is referred to, the computer program instructions are thus understood to be adapted to be executed by processors assigned to or belonging to the respective entities.

[0043] Aspects of the present invention will be described with reference to flowchart illustrations and / or block diagrams of methods, apparatus (systems), and computer program products according to embodiments of the invention. It is noted that each block or portion of the blocks in the flowchart illustrations and / or block diagrams can be implemented by computer program instructions, possibly in the form of computer-executable code. It is also noted that combinations of blocks in different flowchart illustrations and / or block diagrams can be combined if they are not mutually exclusive. These computer program instructions may be provided to a processor of a universal computer, a specialized computer, or other programmable data processing device to produce an apparatus such that the instructions, executed by the processor of the computer or other programmable data processing device, produce means for performing the function(s) / step(s) specified in one or more blocks of the flowchart illustrations and / or block diagrams.

[0044] These computer program instructions may also be stored on a computer-readable medium that can control a computer or other programmable data processing device or other device to operate in a manner such that the instructions stored on the computer-readable medium produce a manufactured product that includes instructions that perform the function / step specified in one or more blocks of the flowcharts and / or block diagrams.

[0045] Computer program instructions may also be stored on a computer, other programmable data processing device, or other device to generate a process executed on a computer, other programmable data processing device, or other device that results in the execution of a series of process steps on the computer, such that the instructions executing on the computer or other programmable data processing device generate a method for performing the function / step specified in a single or multiple blocks of the flowcharts and / or block diagrams. [Brief explanation of the drawings]

[0046] Further advantages and features emerge from the following description taken in conjunction with the accompanying drawings, in which: [Figure 1] FIG. 1 shows a motor vehicle equipped with an ultrasonic measurement unit. [Figure 2A] FIG. 2A shows the emission and reception actions in the first channel of the ultrasonic measurement unit. [Figure 2B] FIG. 2B shows receiving operations in the first and second channels of the ultrasonic measurement unit and emitting operations in the second channel. [Figure 3] FIG. 3 shows a block diagram of the components of the ultrasonic measurement unit. [Figure 4] FIG. 4 shows a block diagram of the components of the ultrasonic measurement unit. [Figure 5] FIG. 5 shows a flow chart of a method of operating an ultrasonic measurement unit. [Figure 6] FIG. 6 shows a time diagram of the ultrasonic amplitude measured by the ultrasonic transducer in the channel. [Figure 7] FIG. 7 shows an illustration of the time division of the measurement period. DETAILED DESCRIPTION OF THE INVENTION

[0047] Ultrasonic measurement systems are increasingly being used, particularly in automotive technology, to detect obstacles and measure their distance. Figures 2A and 2B show, by way of example, the alternate emission of ultrasonic signals 210, 220 on different channels and the reception of echoes 212, 214, 222 of the emitted ultrasonic signals 210, 220. For this purpose, the ultrasonic measurement unit 300 shown in Figure 3 or the ultrasonic measurement unit 400 shown in Figure 4 may be used. The ultrasonic measurement units 300, 400 may implement a method 500 shown in Figure 5 for operating the ultrasonic measurement unit, for example, to detect objects 202, 204 in the vicinity of the motorized vehicle 100, 200. For this purpose, ultrasonic signals 210, 220 may be emitted in the direction of the objects 202, 204, and their echoes 212, 214, 222 may be received and analyzed based on the time and channel of reception.

[0048] FIG. 1 illustrates a motorized vehicle 100, which may be a land-based motorized vehicle such as a passenger car, a goods transporter (van, truck), or an agricultural vehicle. In the non-limiting example of FIG. 1, the motorized vehicle 100 has an electronic control unit 102 that may implement the functions of a control unit and an analysis unit of an ultrasonic measurement unit. To describe these functions, the control unit 102 may, for example, have a dedicated chip permanently programmed therein with program instructions that the chip executes to cause the control unit 102 to realize the functions of the control unit and the analysis unit; or the control unit 102 may have a general-purpose processor that, for example, loads program instructions from memory when the control unit 102 is initialized, and the program instructions are executed by the processor to cause the control unit 102 to perform the functions of the control unit and the analysis unit. A power source 110 (e.g., a battery and / or an alternator) of the motorized vehicle 100 may provide electrical energy to power components connected to the control unit 102, as described below.

[0049] The motorized vehicle 100 has a plurality of ultrasonic transducers 130, which are connected to an interface of the control unit 102, for example, via an analog or digital electrical line system 112. Via the line system 112, the control unit 102 may perform the function of a control unit, controlling one or more of the ultrasonic transducers 130 to alternately emit ultrasonic signals on different channels. Echoes of the emitted ultrasonic signals received by one or more of the ultrasonic transducers 130 may be converted by the ultrasonic transducers 130 into electrical signals and transmitted to the control unit 102 via the line system 112. The control unit 102 may perform the function of an analysis unit, analyzing signals corresponding to the received echoes in order to detect at least one object causing the echoes.

[0050] Further components of the motorized vehicle 100 may be connected to interfaces of the control unit 102. For example, a bus system 114 (e.g., a controller area network, CAN) may connect the steering controller 104, the human-machine interface 106 (e.g., a touchscreen display), and the brake controller 108 to the control unit 102. The control unit 102 may be designed to generate and / or adapt signals intended for the steering controller 104, the human-machine interface 106, and / or the brake controller 108 based on the analysis results of the ultrasonic echoes provided by the analysis unit, and / or to control and / or adapt the functions of the control units and / or the analysis unit in response to user interaction via the human-machine interface 106. In further embodiments, for example, analog or digital electrical line systems 116, 118 may connect a set of operating elements 124 and a set of output units 126 (e.g., loudspeakers) to the control unit 102. The control unit 102 may be designed to generate and / or adapt signals intended for the output unit 126 based on the analysis results of the ultrasound echoes provided by the analysis unit, and / or to control and / or adapt the functions of the control unit and / or the analysis unit in response to user interaction with the operating element 124.

[0051] 2A shows a schematic diagram of snapshots of a motorized vehicle 200 having an ultrasonic measurement unit emitting ultrasonic signals 210, 220 and receiving echoes 212, 214, 222 of the emitted ultrasonic signals at different times. In FIG. 2A, the ultrasonic measurement unit causes an ultrasonic transducer to emit a first ultrasonic signal 210 on a first channel, e.g., at a first frequency. Two obstacles are present within the detection range where the ultrasonic measurement unit can receive echoes of the ultrasonic signal via one or more ultrasonic transducers, within limits specified by the measurement sensitivity and, if necessary, the duration of the measurement period. Obstacle 204 is at a greater distance from motorized vehicle 200 than obstacle 202.

[0052] At the time shown in Figure 2A, the first ultrasonic signal 210 has propagated to the nearest obstacle 202 and the farthest obstacle 204, and a first echo 212 of the first ultrasonic signal 210 that has reflected back from the nearest obstacle 202 in the direction of the motorized vehicle 200 has just reached one of the ultrasonic transducers. At the time shown in Figure 2A, the analysis unit can thus detect the obstacle 202 by analyzing the signal corresponding to the first echo 212 of the first ultrasonic signal 210. In Figure 2A, no ultrasonic echo has yet been reflected from the obstacle 204 in the direction of the motorized vehicle 200.

[0053] Figure 2B shows the motorized vehicle 200 and obstacles 202, 204 at a later time. In Figure 2B, the ultrasonic measurement unit causes the same ultrasonic transducer to emit a second ultrasonic signal 220 on a second channel, e.g., at a second frequency. The two obstacles 202, 204 are still within the detection range of the ultrasonic measurement unit, and obstacle 204 is still at a greater distance from the motorized vehicle 200 than obstacle 202. At the time shown in Figure 2B, the second ultrasonic signal 220 has been reflected (echo 222) from the nearest obstacle 202. Therefore, at the time of Figure 2B, the analysis unit can detect obstacle 202 by analyzing the signal corresponding to echo 222.

[0054] In Figure 2B, the ultrasonic signal 210 from the obstacle 204 is meanwhile also reflected as a second echo 214. Therefore, at the time shown in Figure 2B, the analysis unit can detect the obstacle 204 by analyzing the signal corresponding to the second echo 214. This principle described with respect to a single ultrasonic transducer can also be applied to multiple ultrasonic transducers, as shown schematically in the form of a triangle in Figures 2A and 2B.

[0055] FIG. 3 shows a block diagram of an exemplary ultrasonic measurement unit 300. The ultrasonic measurement unit 300 comprises a control unit 310 and an analysis unit 320. The control unit 310 has an output via which the control unit 310 can emit signals 312 to one or more ultrasonic transducers, causing the one or more ultrasonic transducers to emit ultrasonic signals alternately on different channels in each case. The control unit 310 may have an interface for connecting to a signal line 311 via which the control unit 310 can exchange signals with other units (e.g., signals for controlling and / or configuring the function of the control unit 310, signals for sending the output of the control unit 310, e.g., status information). The control unit 310 may have an interface for connecting to a signal line 313 via which the control unit 310 can exchange signals with the analysis unit 320 (e.g., time synchronization signals, trigger signals, or other control signals). The analysis unit 320 has an input, via which the analysis unit 320 can receive signals 314 from one or more ultrasonic transducers, the signals corresponding to ultrasonic signals (e.g., echoes of the ultrasonic signals) received by the one or more ultrasonic transducers. The analysis unit 320 may further have an interface for connection to a signal line 316, via which the analysis unit 320 can exchange signals with other units (e.g., signals for controlling and / or configuring the function of the analysis unit 320, signals for transmitting the output of the analysis unit 320, such as status information and / or information about obstacles detected by the received signals, such as the distance of the nearest obstacle to the emitting ultrasonic transducer, etc.). The analysis unit 320 may also have an interface for connection to a signal line 313, via which the analysis unit 320 can exchange signals (e.g., time synchronization signals, trigger signals, or other control signals) with the control unit 310.

[0056] 4 shows a block diagram of an ultrasonic measurement unit 400. The ultrasonic measurement unit 400 comprises a control unit 410, an analysis unit 420 and one or more ultrasonic transducers 415, as used, for example, in FIGS. 2A and 2B. The control unit 410 has an output via which it can emit signals 412 to one or more ultrasonic transducers 415, which signals cause the one or more ultrasonic transducers 415 to emit ultrasonic signals alternately in different channels in each case. The configuration of the analysis unit 420 and the control unit 410, including the signal line 411, the interface 413 and the signal line 416, can correspond to FIG. 3 (therein references 310, 320, 311, 313 and 316).

[0057] The analysis unit 420 has an input via which the analysis unit 420 can receive signals 414 from one or more of the ultrasonic transducers 415, which signals correspond to ultrasonic signals (e.g., echoes of ultrasonic signals) received by the ultrasonic transducers 415. The one or more ultrasonic transducers 415 may have an interface for receiving signals 412 from the control unit 410 and for emitting signals 414 to the analysis unit 420, a transmitter device for generating ultrasonic signals based on the received signals 412, and a receiving device, for example, for amplifying the received ultrasonic signals and for generating signals 414 based on the received ultrasonic signals.

[0058] 5 shows a flowchart with steps of a method 500 that can be implemented by the ultrasonic measurement unit disclosed herein. Method 500 includes the ultrasonic measurement unit controlling 502, via its control unit, one or more ultrasonic transducers to emit ultrasonic signals alternately on different channels in each case. Method 500 further includes step 504, in which an analysis unit of the ultrasonic measurement unit analyzes signals resulting from echoes generated from the ultrasonic signals alternately emitted on different channels to detect at least one object that generates the echoes. Successful performance of step 504 requires that step 502 has been previously performed at least once to generate potential echoes that can be analyzed by the analysis unit. Alternatively, steps 502 and 504 can be performed in any order, repeated, and / or parallelized in time.

[0059] FIG. 6 shows an example time characteristic diagram of the signal amplitude measured by an ultrasonic transducer at the beginning of an emission and reception period for a single channel. The time and duration values ​​mentioned in connection with FIG. 6 are used for illustrative purposes only and are not to be construed as specifics for limiting the invention in any way. The emission and reception period begins with excitation of a vibration unit (e.g., a membrane) of the ultrasonic transducer to emit an ultrasonic signal at time t=0. The excitation signal output by the control unit of the ultrasonic measurement device, which causes the vibration unit (e.g., a piezoelectric element) of the ultrasonic transducer to vibrate from t=0, is terminated after a predetermined excitation duration 602 (e.g., 250 μs) has elapsed. After the excitation signal is terminated, the vibration unit continues to vibrate for a reverberation duration 604 having a known nominal value (e.g., 1 ms) until the measured amplitude falls below a known or continuously updated noise level. The sum of the excitation duration 602 and the reverberation duration 604 forms an emission period 606 for a given channel (e.g., 1.25 ms). The emission period 606 is followed by a receive period 610, the duration of which (e.g., 30 ms) is greater than the duration of the emission period, and therefore the end of the receive period is not shown in FIG. 6. During the receive period 610, no emission activity is intended on any of the channels served by the ultrasonic measurement unit. The emission period 606 and the receive period 610 are collectively referred to as the emission and receive periods.

[0060] At a time after the end of the emission period 606 (shown as a delay time 608 from t=0), the first echo of the ultrasonic signal emitted during the emission period 606 arrives at the ultrasonic transducer, causing an increase in amplitude that the analysis unit of the ultrasonic measurement unit detects, for example, by comparing it with a predetermined threshold representing the maximum acceptable noise level. From the delay time Δt 608 and the speed of sound c, the analysis unit can determine the distance d=cΔt / 2 of the obstacle that caused the echo received after the delay time 608.

[0061] FIG. 7 shows a timeline with different time periods of a measurement period 700 marked. The measurement period 700 is divided into a first emission and reception period 710 and a second emission and reception period 720. In the example of FIG. 7, without limitation of generality, the first emission and reception period 710 and the second emission and reception period 720 are the same length. The first emission and reception period 710 is divided into a first emission period 712 and a first reception period 714, and the second emission and reception period 720 is divided into a second emission period 722 and a second reception period 724. In the example of FIG. 7, without limitation of generality, the first emission period 712 and the second emission period 722 are the same length, and the first reception period 714 and the second reception period 724 are the same length. In another non-limiting example, the measurement period 700 has a duration of 50 ms divided into a first emit period of 1.4 ms, a first receive period of 23.6 ms, a second emit period of 1.4 ms, and a second receive period of 23.6 ms.

[0062] The measurement period 700 can be repeated with the same or other durations of the individual emission and reception periods. The ultrasonic measurement unit implementing the measurement period 700 is configured to control the ultrasonic transducer to emit ultrasonic signals alternately on different channels. In the example shown in Figure 7, the ultrasonic measurement unit, through its control unit, controls the ultrasonic transducer during a first emission period 712 to emit a first ultrasonic signal on a first channel and during a second emission period 722 to emit a second ultrasonic signal on a second channel.

[0063] 6 , during the first receiving period 714, the analysis unit of the ultrasonic measurement unit may analyze, in the first channel, signals corresponding to echoes received by the ultrasonic transducer of the first ultrasonic signal emitted during the first emitting period 712 to detect one or more objects causing echoes in the near range. Optionally, during the first receiving period 714, the analysis unit additionally analyzes, in the second channel, signals corresponding to echoes received by the ultrasonic transducer of the second ultrasonic signal emitted during the second emitting period 722 of the previous measurement period 700 to detect one or more further objects causing echoes in the first far range. Also optionally, during the first receiving period 714, the analysis unit additionally analyzes, in the first channel, signals corresponding to echoes received by the ultrasonic transducer of the first ultrasonic signal emitted during the first emitting period 712 of the previous measurement period 700 to detect one or more further objects causing echoes in a second far range that is farther from the emitting ultrasonic transducer than the first far range. The analysis unit can distinguish between echoes arriving on the same channel based on their maximum amplitude from a previous measurement period 700 having known time characteristics of the maximum amplitude of the ultrasonic echoes, and echoes arriving on the same channel from ultrasonic signals emitted during the current measurement period 700.

[0064] During the second receiving period 724, the analysis unit of the ultrasonic measurement unit analyzes, on the second channel, signals corresponding to echoes received by the ultrasonic transducer of the second ultrasonic signal emitted during the second emitting period 722 to detect one or more objects causing echoes at an even closer range. Furthermore, the analysis unit analyzes, on the first channel, signals corresponding to echoes received by the ultrasonic transducer of the first ultrasonic signal emitted during the first emitting period 712 of the current measurement period 700 to detect one or more further objects causing echoes at a first, further far range during the second receiving period 724. Optionally, during the second receiving period 724, the analysis unit additionally analyzes, on the second channel, signals corresponding to echoes received by the ultrasonic transducer of the second ultrasonic signal emitted during the second emitting period 722 of the previous measurement period 700 to detect one or more further objects causing echoes from a second, further far range. The end of the second receiving period 724 may be followed by a new measurement cycle 700 having a further first emitting period 712 .

[0065] It should be noted that the embodiments of the invention described herein can be combined with each other in any way, unless the combination of two particular embodiments is made impossible for technical reasons. List of Reference Numbers 100 Powered Vehicles 102 control unit 104 Steering Controller 106 Human-Machine Interface 108 Brake Controller 110 Power source 112 Line System 114 Bus System 116 Line System 118 Line System 124 Operational Elements 126 output units 130 Ultrasonic Transducer 200 Powered Vehicles 202 Obstacles 204 Obstacles 210 First ultrasonic signal 212 First echo of first ultrasonic signal 214 Second echo of first ultrasonic signal 220 Second ultrasonic signal 222 Echo of the second ultrasonic signal 300 Ultrasonic Measuring Unit 310 Control Unit 311 Signal Line 312 Emission Signal 313 Signal Line 314 Receiving signal 316 Signal Line 320 analytical units 400 Ultrasonic Measuring Unit 410 Control Unit 411 Signal Line 412 Emission Signal 413 Signal Line 414 Receiving signal 415 Ultrasonic Transducer 416 Signal Line 420 Analysis Units 500 Method for operating an ultrasonic measuring device 502 Oscillation Control 504 Detection Analysis 602 Excitation Time 604 Reverberation Time 606 Release Period 608 Delay Time 610 Receipt Period 700 measurement period 710 First Release and Receipt Period 712 First Release Period 714 First Receipt Period 720 Second Release and Receipt Period 722 Second Release Period 724 Second Receipt Period

Claims

1. An ultrasonic measurement unit (300, 400), in particular for use in a vehicle (100, 200), comprising a control unit (310, 410) and an analysis unit (320, 420), - said control unit (310, 410) is arranged to control (502) the ultrasonic transducers (130, 415) to emit ultrasonic signals (210, 220) alternately on different channels; said analysis unit (320, 420) is arranged to analyze (504) echoes (212, 214, 222) arising from said ultrasound signals (210, 220) in said channels in order to detect at least one object (202, 204) causing said echoes; Ultrasonic measurement unit (300, 400).

2. 2. The ultrasonic measurement unit (300, 400) of claim 1, wherein the controlling (502) and the analyzing (504) occur in a measurement period (700), and the measurement period (700) is periodically repeated.

3. 3. The ultrasonic measurement unit (300, 400) of claim 2, wherein within the measurement period (700), the ultrasonic signals include at least a first ultrasonic signal (210) in a first channel and a second ultrasonic signal (220) in a second channel.

4. 4. The ultrasonic measurement unit (300, 400) of claim 3, wherein the analysis (504) takes into account an echo (212) occurring in the first channel between the emission of at least the two ultrasonic signals (210, 220), and the analysis takes into account echoes (212, 214, 222) occurring in the first channel and the second channel after the emission of the second ultrasonic signal (220).

5. An ultrasonic measurement unit (300, 400) as described in claim 3 or 4, wherein a maximum spatial measurement distance for the ultrasonic measurement unit (300, 400) is determined, and the length of the measurement period (700) is set so that echoes (212, 214) resulting from the first ultrasonic signal (210) and caused by an object (202, 204) at the maximum measurement distance can be detected within the measurement period (700).

6. The ultrasonic measurement unit (300, 400) according to any one of claims 2 to 5, wherein the analysis unit (320, 420) is arranged to analyze echoes (212, 214, 222) arising from the ultrasonic signal (210, 220) continuously in all channels within the measurement period (700).

7. The ultrasonic measurement unit (300, 400) according to any one of claims 1 to 6, wherein the analysis unit (320, 420) is arranged to receive the echoes (212, 214, 222) from the same ultrasonic transducer (130, 415) from which the ultrasonic signal (210, 220) was emitted.

8. An ultrasonic measurement unit (300, 400) according to any one of the preceding claims 2 to 7, wherein the different channels comprise at least three channels, and within the measurement period (700), the emission of the successive ultrasonic signals (210, 220) is performed at different time intervals, the different time intervals being constant for periodically repeated executions of the measurement period (700).

9. 8. An ultrasonic measurement unit (300, 400) according to any one of the preceding claims 2 to 7, wherein during the periodically repeated execution of the measurement period (700), the emission of the successive ultrasonic signals (210, 220) is performed at different time intervals for at least a portion of the measurement period (700).

10. 10. The ultrasonic measurement unit (300, 400) according to claim 1, further comprising an ultrasonic transducer (415) arranged to receive the echoes (212, 214, 222) arising from the ultrasonic signals (210, 220) in all channels and to send them to the analysis unit (320, 420).

11. A method (500) for operating an ultrasonic measurement unit (300, 400), in particular for use in a vehicle (100, 200), said ultrasonic measurement unit (300, 400) comprising a control unit (310, 410) and an analysis unit (320, 420), said method (500) comprising: - controlling (502) by said control unit (310, 410) ultrasonic transducers (130, 415) to emit ultrasonic signals (210, 220) alternately on different channels; - analyzing (504) by said analysis unit (320, 420) echoes (212, 214, 222) arising from said ultrasound signals (210, 220) in said channels in order to detect at least one object (202, 204) causing said echoes (212, 214, 222); A method (500) for operating an ultrasonic measurement unit (300, 400), comprising:

12. A computer program product, in particular a computer-readable storage medium, the computer program product comprising computer-executable code, the code being executable by at least one processor of a computer device (102) to cause the computer device (102) to perform the method (500) of claim 11.

Images