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

Abstract

The invention relates to an ultrasonic measuring unit, in particular for a vehicle, comprising a control unit and an evaluation unit, the control unit being designed to control an ultrasonic transducer to alternately emit ultrasonic signals on different channels, and the evaluation unit being designed to evaluate the echoes generated by the ultrasonic signals on each channel, in this way, at least one echo-producing object is detected.

Description

Technical Field

[0001] The present invention relates to an ultrasonic measurement unit, and in particular to an ultrasonic measurement unit for a vehicle, a method for operating an ultrasonic measurement unit, and a corresponding computer program product. Background Art

[0002] Motor vehicles are increasingly equipped with ultrasonic sensors, which are usually integrated into the vehicle body and are designed to help the driver detect obstacles on the driving path of the motor vehicle in a timely manner, especially in areas where the driver has difficulty seeing, and to evaluate the distance to the obstacles. The operating principle of such ultrasonic sensors is to emit ultrasonic signals and detect the echoes of the emitted ultrasonic signals, which come from any obstacle within the detection range of the sensor. The ultrasonic pulses generated for this purpose can have a constant frequency in time. In addition, methods using time-variable frequencies ("chirps") and multiple independent transmit and receive channels (e.g., by frequency division multiplexing) are also known.

[0003] Today, ultrasonic sensors are widely used in various fields, from parking assistance systems to blind spot detection assistance systems. In the field of autonomous driving in urban environments ("city driving"), ultrasonic sensors have so far been used very little. On the one hand, this is because higher-performance systems are desired for partial or fully autonomous driving, and on the other hand, due to the limitation of the speed of sound, there are limitations in the measurement range and sampling rate of ultrasonic sensors.

[0004] The speed of sound largely determines the measurement range and sampling rate of ultrasonic sensors. Therefore, in the automotive field, it is already conceivable today to achieve a measurement range of up to 10 m using ultrasonic sensors. Due to the speed of sound, under normal circumstances, it takes up to 60 ms to perform such a measurement using an ultrasonic sensor. Therefore, in the best case, 16 measurements can be performed per second. If multiple sensors are now used in the system and multiple measurement steps are required to achieve full coverage of the system, the measurement rate of the entire system usually drops to 5 - 8 updates per second. Such a low update rate has a significant negative impact on object detection, especially on object tracking, which is why this situation cannot be practically applied at present. Summary of the Invention

[0005] The object of the present invention is to provide an improved ultrasonic measurement unit, as well as a corresponding method and computer program product. The fundamental problem of the present invention is solved by the features of the independent claims. Embodiments are specified in the dependent claims.

[0006] To solve this problem, the present invention provides an ultrasonic measurement unit, especially suitable for a vehicle, which includes a control unit and an analysis unit, wherein

[0007] The control unit is designed to control the ultrasonic transducer to alternately transmit ultrasonic signals on different channels.

[0008] The analysis unit is designed to analyze the echoes generated by the ultrasonic signals on the channels to detect at least one object that causes the echoes.

[0009] According to the present invention, the ultrasonic measurement unit alternately transmits ultrasonic signals, such as 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 the echo of the first ultrasonic signal transmitted on the first channel among two or more different channels from the echo of the second ultrasonic signal transmitted on another second channel among two or more different channels. Without limitation, such characteristics defining the channel may include characteristic frequency, characteristic spectrum, characteristic time-frequency curve, characteristic amplitude, and / or characteristic phase angle at the start of the corresponding ultrasonic signal transmission operation.

[0010] The ultrasonic measurement unit can use one or more ultrasonic transducers for transmission and reception. Multiple ultrasonic transducers can be used to transmit ultrasonic signals. However, on each ultrasonic transducer used for transmission, at least two ultrasonic signals are alternately transmitted on different channels. For example, the transmitting ultrasonic transducer can be specifically designed for two or more implemented channels. Transmitting ultrasonic signals on different channels using the same ultrasonic transducer can achieve very efficient obstacle detection with minimal technical effort and material use. In this case, obstacle detection can be performed at a high sampling rate.

[0011] In principle, part or all of the echoes to be processed by the analysis unit can be received by the same ultrasonic transducer that transmits the original signal of the corresponding echo. This can also reduce the technical effort and material use required for obstacle detection using multi-channel ultrasound. However, one or more other ultrasonic transducers can also be used to receive the echoes of the ultrasonic signals transmitted by the transmitting ultrasonic transducer. Preferably, part or all of the ultrasonic transducers can transmit and receive on all implemented channels. However, the available ultrasonic sensors can also be additionally divided into sensors that only transmit and / or receive on a part of the channels, and sensors that only transmit and / or receive on another part of the channels. In particular, each receiving ultrasonic transducer can be assigned to one or more channels or be configured to receive on one or more channels. The specific ultrasonic transducers for one or more channels may be different in design to better meet the specific requirements of the channels implemented for each ultrasonic transducer. For example, different frequency ranges can correspond to the respective channels, and ultrasonic transducers operating in different frequency ranges can be optimized accordingly to achieve maximum conversion efficiency within their respective frequency ranges.

[0012] It is also possible to use ultrasonic transducers that are specifically designed to emit ultrasonic signals or specifically designed to receive echoes of the original ultrasonic signals with an amplitude less than that of the echoes that form the echoes. The transmitting transducer and the receiving transducer can be different in design from each other in order to better meet the specific requirements of transmission and reception respectively. For example, the ultrasonic transmitting transducer can be designed to generate a large-amplitude ultrasonic signal with as little distortion as possible, while the ultrasonic receiving transducer can be designed to detect the echoes of ultrasonic signals with as high a sensitivity as possible in a low-noise manner.

[0013] The control unit and the analysis unit can be implemented as different units or components that work independently of each other in terms of signal transmission. Alternatively, the control unit and the analysis unit can be integrated into the same component or unit. For example, the control unit and the analysis unit can be implemented by analog or digital electronics, especially in the form of one or more integrated circuits. The control unit and the analysis unit can also be implemented as software modules executed on a general-purpose or special-purpose processor (especially a central processing unit (CPU)). One or more communication channels can be implemented between the control unit and the analysis unit, and these communication channels allow signals to be transmitted between the above two units, not only the emission of ultrasonic signals and the reception of the echoes of these emitted ultrasonic signals.

[0014] Preferably, the control unit controls the ultrasonic transducer by outputting an electrical signal. Then, the ultrasonic transducer can be designed to convert between electrical energy and mechanical vibration. For example, the ultrasonic transducer can have a diaphragm that is excited by a piezoelectric element to emit ultrasonic signals, or enter an acoustic oscillation state when receiving ultrasonic signals and transmit the acoustic oscillation to the piezoelectric element. Then, the analysis unit can receive and analyze the electrical signal output by the piezoelectric element that corresponds to the received ultrasonic signal.

[0015] According to one embodiment, the control and analysis are carried out within a measurement cycle, and the measurement cycle is repeatedly executed cyclically. In particular, the change in the distance between the ultrasonic transmitting transducer and the obstacle can be detected thereby. As shown in the following detailed description, alternately emitting ultrasonic signals on different channels can not only effectively improve the detection rate of obstacles, but also particularly measure multiple distance ranges (for example, a short range up to 5 m and a long range from 5 to 10 m) quasi-simultaneously at a high or optimized short-range sampling rate. In particular, the cyclic repetition of the measurement cycle can allow the reception of the echoes of the ultrasonic signals emitted in an earlier measurement cycle. In this way, for example, the obstacles within the detection range can be continuously detected at a high sampling rate.

[0016] According to one embodiment, during a measurement cycle, the ultrasonic signal at least includes a first ultrasonic signal on a first channel and a second ultrasonic signal on a second channel. Thus, the ultrasonic measurement unit will first emit a first ultrasonic signal on the first channel. Subsequently, during a predefined first reception period, the ultrasonic measurement unit may receive echoes originating from the first ultrasonic signal. Since it is temporally adjacent to the emission of the first ultrasonic signal, the echoes received during this first reception period originate from reflections by obstacles within the "near range" relative to the ultrasonic transducer.

[0017] After the first reception period, but still within the same measurement cycle, the ultrasonic measurement unit will emit a second ultrasonic signal on the second channel. In this case, the second channel is different from the first channel. Subsequently, during a predefined second reception period, the ultrasonic measurement unit may receive echoes of the second ultrasonic signal, which also originate from the near range but are received on the second channel.

[0018] According to one embodiment, the analysis takes into account at least the echoes generated on the first channel between the emission of the two ultrasonic signals, and the analysis takes into account the echoes generated on the first channel and the second channel after the emission of the second ultrasonic signal. Thus, during the second reception period, the ultrasonic measurement unit may additionally receive on the first channel echoes of the first ultrasonic signal previously emitted on the first channel. Since the echoes received during the second reception period have propagated during the duration of the first reception period and the emission duration 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 measurement unit from a greater distance corresponding to this longer propagation duration.

[0019] Therefore, if the entire measurement cycle is considered, it is possible to detect obstacles in the near range and the far range using a single transmitting ultrasonic transducer within the measurement cycle, where, for example, the sampling rate in the near range is twice the sampling rate in the far range. In this way, in addition to making two measurements in the near range, a far-range measurement can also be made during the second reception period without restricting the repetition rate.

[0020] For example, the ultrasonic measurement unit is designed to receive echoes of ultrasonic signals on at least two channels (the above-mentioned channels) simultaneously, with the pause between the two measurements being as short as possible and the measurement time being precisely known. In particular, it may be advantageous if these channels have low "coupling", i.e., if the emission of the 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 can continue to receive echoes of the first ultrasonic signal on the first channel even when the second ultrasonic signal is being emitted, so there is no "blind spot" between the near-range echoes and the far-range echoes. Such a blind spot corresponds to a spatial region where obstacles cannot be detected ("blind spot").

[0021] The above example illustrates the basic principle of the present invention based on ultrasonic signals transmitted and received on two channels. Of course, the ultrasonic measurement unit can also transmit more than two ultrasonic signals on more than two different channels. It can also be configured to receive the echoes of the ultrasonic signals transmitted on these channels. In this way, the spatial detection range of the ultrasonic measurement unit can be divided into more than two distance ranges. For example, for a three-channel ultrasonic measurement unit, first, there may be a short-distance range where, within a single measurement cycle, echoes of ultrasonic signals from within this range can be received on all three channels. In addition, there may be an intermediate-distance range where, within the same measurement cycle, echoes from within this range can be received on the first two channels. Finally, in this case, there may also be a long-distance range where, within the same measurement cycle, only the echo of the first ultrasonic signal transmitted earliest can be received on the first channel. This concept can be easily applied to any number of channels within each measurement cycle.

[0022] According to one embodiment, the maximum spatial measurement distance of the ultrasonic measurement unit is defined, where the length of the measurement cycle is set such that within the measurement cycle, an echo generated by reflection from an object located at the maximum measurement distance and caused by the first ultrasonic signal can be detected. The maximum spatial measurement distance (referred to herein as the range) is the maximum distance at which a detectable obstacle can exist. Thus, within the measurement cycle, an echo from this farthest obstacle can be detected. It is generated by the earliest transmitted ultrasonic signal within that measurement cycle.

[0023] The ultrasonic signals emitted by the ultrasonic transducer generally propagate at m / s of the speed of sound. In time t, the distance traveled by the ultrasonic signal is . For an obstacle located at a distance L, this results in a delay time between the transmission of the ultrasonic signal and the sensing of the echo from distance L of . For a cycle duration T, the maximum spatial measurement distance given is . For example, if a range of 10 m is required, within a tolerance of, for example, 5%, this requires a cycle duration of 60 ms.

[0024] In the case of alternating transmission on N channels, the cycle duration is divided into T / N sub-intervals, each having a transmission period for transmitting on one of the N channels and a reception period for receiving echoes. Compared with a single-channel ultrasonic measurement unit with a cycle duration of , echoes of ultrasonic signals received in the second or later sub-intervals (which were transmitted in previous sub-intervals) can achieve a larger range (for example, doubling the range when using two channels) without worrying about limitations on the short-distance range measurement rate.

[0025] It should be noted that, compared with a single-channel ultrasonic measurement unit having the same cycle duration the multi-channel ultrasonic measurement unit disclosed herein can monitor a closer part (distance range) (e.g., a short-distance range) within the detection range defined by the range at a higher sampling rate than a farther part (distance range) (e.g., a long-distance range) within the detection range. That is to say, for example, a short-distance range. This is because the ultrasonic measurement unit does not have to wait until the start of a new measurement cycle before emitting a new ultrasonic signal that allows monitoring of the short-distance range. Instead, it can utilize the delay time of the echoes from the farther distance range to emit ultrasonic signals on other channels to achieve a higher frequency monitoring of the short-distance range.

[0026] For the sake of simplicity of illustration, taking a two-channel ultrasonic measurement unit preferably used but not limited to herein as an example, this means that objects within a short-distance range can be detected and objects within a long-distance range can be identified early. This may bring some potential applications, especially in urban areas. For example, the ultrasonic measurement unit can be used in a motor vehicle to determine whether a turning lane is occupied. The larger range of the ultrasonic measurement unit can achieve this function even when the turning lane is separated from the currently used lane by more than one lane. Especially for the short-distance range, the high sampling rate achieved by the present invention will be particularly important. Here, the risk brought by short-term distance changes with an obstacle is greater than that in the long-distance range.

[0027] According to one embodiment, the analysis unit is configured to continuously analyze the echoes generated by the ultrasonic signals on all channels during a measurement cycle. In this way, the analysis unit can analyze the echoes (derived from the previous measurement cycle) at any time during the repetition of the measurement cycle on a given channel, especially during the "early" reception period. In this way, a farther distance range within the range of the ultrasonic measurement unit can be continuously monitored at the same measurement rate as the distance range closer to the ultrasonic transducer that emits the ultrasonic waves. If the transmission scheme is known (i.e., in which sub-interval of a given measurement cycle and on which channel the transmission is performed), the delay time of the echoes received on a given channel before retransmission can be reconstructed based on the reception period and the characteristics of the channel on which the echoes are received.

[0028] According to one embodiment, the analysis unit is configured to receive the echoes from the same ultrasonic transducer that emits the ultrasonic signals. Compared with an ultrasonic measurement unit having different transmitting and receiving transducers, it is therefore sufficient to equip the ultrasonic measurement unit with a single ultrasonic transducer. Therefore, a simpler design of the ultrasonic measurement unit can be achieved and the material usage can be reduced.

[0029] According to one embodiment, different channels include at least three channels, wherein during a measurement cycle, consecutive ultrasonic signals are emitted at different time intervals, and the different time intervals for periodically repeating the execution of the measurement cycle are constant. During a given first measurement cycle, the ultrasonic signals continuously emitted on the first pair of channels are emitted at a time interval emitted. This time interval is different from the time interval for continuously emitting ultrasonic signals on another second pair of channels during the same measurement cycle. The condition that the different time intervals for periodically repeating the execution of the measurement cycle are constant means that during another second measurement cycle, the ultrasonic signals emitted on the first pair of channels are emitted at the same time interval as the corresponding previous one in the first measurement cycle. Therefore, the spatial region of the above-mentioned "blind zone" can be minimized or even eliminated.

[0030] During the emission of ultrasonic signals, it is possible that the analysis unit fails to detect the echo of the first ultrasonic signal during the second emission period, during which a second ultrasonic signal following the first ultrasonic signal is emitted ("blind zone, blind spot"). During the emission process, and if necessary, due to the reverberation generated by the diaphragm of the ultrasonic transducer, the detection ability of the same transducer may be reduced or even unable to detect even after the emission. Therefore, for example, due to the reverberation of the ultrasonic transducer after the excitation force stops, the actual duration of the "emission period" of the ultrasonic signal may significantly exceed the duration of the actual control signal generating the excitation force.

[0031] As described above, by alternately emitting using at least three channels, the measurement cycle can be divided into at least three corresponding sub-intervals in time, and the spatial detection range of the obstacle can be correspondingly divided into at least three distance ranges corresponding to the time sub-intervals. If now the time interval between two emission operations is changed between each measurement cycle, then the size of the non-detectable "blind zone" distance range at the transition between two adjacent distance ranges can generally be reduced.

[0032] According to one embodiment, during the cyclic repetition of the measurement cycle, at least in some measurement cycles, the emission of consecutive ultrasonic signals is performed at different time intervals. For example, in the case of two measurement cycles, if the emission times of the respective second ultrasonic signals differ by or in time difference, then the ultrasonic transducer can thus receive the echo of the ultrasonic signal additionally even during a time period Δt in which a new ultrasonic signal would already be emitted in one of the measurement cycles. Compared with dividing the measurement cycle into sub-intervals of equal length, this reduces the area of any "blind spots". For example, during different measurement cycles, the relative change in the time interval of a given pair of channels for continuously emitting ultrasonic signals is at least 3%, preferably at least 5%.

[0033] According to one embodiment, the ultrasonic measurement unit further includes an ultrasonic transducer, wherein the ultrasonic transducer is configured to receive echoes generated by ultrasonic signals on all channels and transmit them to the analysis unit. This does not exclude the ultrasonic measurement unit being able to have multiple ultrasonic transducers. In the case where the ultrasonic measurement unit has multiple ultrasonic transducers, this in turn means that the echoes detected by a given ultrasonic transducer do not necessarily have to originate from ultrasonic signals emitted by the same ultrasonic transducer.

[0034] In another aspect, the present invention provides a method of operating an ultrasonic measurement unit, particularly for use in a vehicle, wherein the ultrasonic measurement unit includes a control unit and an analysis unit, and wherein the method includes:

[0035] Controlling, by the control unit, the ultrasonic transducer to alternately transmit ultrasonic signals on different channels,

[0036] Analyzing, by the analysis unit, the echoes generated by the ultrasonic signals on the channels to detect at least one object generating the echoes.

[0037] In another aspect, the present invention provides a computer program product, particularly a computer-readable storage medium, wherein the computer program product includes computer-executable code, and wherein the code is executable by at least one processor of a computer device to cause the computer device to perform the methods disclosed herein.

[0038] Those skilled in the art will understand that aspects of the present invention can be implemented as an apparatus, a method, a computer program, or a computer program product. Thus, aspects of the present invention can take the form of a pure hardware embodiment, a pure software embodiment (including firmware, memory software, microcode, etc.), or an embodiment combining software and hardware aspects, which may be collectively referred to herein as a "circuit", "module", or "system". Additionally, aspects of the present invention can take the form of a computer program product carried by a computer-readable medium or multiple computer-readable media in the form of computer-executable code. The computer program equally includes computer-executable code. "Computer-executable code" may also be referred to as "computer program instructions".

[0039] Any combination of one or more computer-readable media may be used. A computer-readable medium may be a computer-readable signal medium or a computer-readable storage medium. As used herein, "computer-readable storage medium" includes a tangible storage medium that can store instructions executable by a processor of a computer device. A computer-readable storage medium may be referred to as a computer-readable non-volatile storage medium. A computer-readable storage medium may also be referred to as a tangible computer-readable medium. In some embodiments, a computer-readable storage medium is also capable of storing its data such that it can be accessed by a processor of a computer device. Examples of computer-readable storage media include, but are not limited to: floppy disks, magnetic hard disks, solid state disks, flash memory, USB keys, random access memory (RAM), read-only memory (ROM), optical disks, magneto-optical disks, and register files of a processor. Examples of optical disks include compact discs (CDs) and digital versatile discs (DVDs), such as CD-ROM, CD-RW, CD-R, DVD-ROM, DVD-RW, or DVD-R discs. The term computer-readable storage medium also refers to various types of recording media suitable for retrieval from a computer device via a network or communication link. For example, data can be retrieved via a modem, the Internet, or a local area network. Computer-executable code executed on a computer-readable medium can be transmitted via any suitable medium, including but not limited to wireless, wired, fiber optic cable, radio frequency, etc., or any suitable combination of the foregoing media.

[0040] A computer-readable signal medium may include a propagated data signal that contains computer-readable program code, for example, in the form of a baseband signal (baseband) or as part of a carrier signal (carrier). Such a propagated signal may take any form, including but not limited to electromagnetic form, optical form, or any suitable combination thereof. A computer-readable signal medium may be any computer-readable medium that is not a computer-readable storage medium and that can be used in connection with or associated with a system, apparatus, or device that can transmit, distribute, or transport a program for execution of instructions.

[0041] "Computer memory" or "memory" is an example of a computer-readable storage medium. Computer memory is any memory directly accessible by a processor.

[0042] "Computer data storage" or "data storage" is another example of a computer-readable storage medium. Computer data storage is any non-volatile computer-readable storage medium. In some embodiments, computer memory may also be computer data storage, and vice versa.

[0043] As used herein, a "processor" includes an electronic component capable of executing a program, machine-executable instructions, or computer-executable code. A computer device that includes a "processor" should be understood to potentially include more than one processor or processing core. For example, a processor can be a multi-core processor. A processor can also refer to a group of processors within a single computer system or distributed across multiple computer systems. The term "computer device" or "computer" should also be understood to potentially refer to a group or a single computer device or computer network, where each device or computer includes one or more processors. Computer-executable code can be executed by multiple processors, which can be distributed within the same computer device or even across multiple computers.

[0044] Computer-executable code can include machine-executable instructions or programs that cause a processor to perform operations in accordance with aspects of the present invention. The computer-executable code for performing operations in accordance with aspects of the present invention can be written in any combination of one or more programming languages, including object-oriented programming languages (such as Java, Smalltalk, C++, or similar languages) and traditional procedural programming languages (such as the programming language "C" or similar programming languages), and be translated into machine-executable instructions. In some cases, the computer-executable code can be in the form of a high-level programming language or a pre-translated form and can be used in conjunction with an interpreter that generates machine-executable instructions.

[0045] Computer-executable code can be executed entirely on a user's computer, partially on a user's computer (as a stand-alone software package), partially on a user's computer and partially on a remote computer, or entirely on a remote computer or server. In the latter case, the remote computer can be connected to the user's computer via any type of network, including a local area network (LAN) or a wide area network (WAN), or can be connected to an external computer (e.g., connected to the Internet via an Internet service provider).

[0046] Computer program instructions can be executed on one processor or on multiple processors. If multiple processors are used, these processors can be distributed across multiple different entities (such as clients, servers). Each processor can execute a portion of the instructions for the corresponding entity. Thus, if a system or method that includes multiple entities is mentioned, it should be understood that these computer program instructions are adapted to be executed by processors assigned to or belonging to the corresponding entities.

[0047] Aspects of the present invention are described in conjunction with the flowchart illustrations and / or block diagrams of methods, apparatus (systems), and computer program products according to embodiments of the invention. It should be noted that each block or portion of blocks in the flowchart illustrations and / or block diagrams can be implemented by computer program instructions, which may exist in the form of computer-executable code. It should also be noted that if the blocks in different flowchart illustrations and / or block diagrams are not mutually exclusive, they can be combined. These computer program instructions can be provided to a processor of a general-purpose computer, a special-purpose computer, or other programmable data processing apparatus to produce a machine, such that the instructions executed by the processor of the computer or other programmable data processing apparatus produce a means for implementing the functions / steps specified in the block or blocks of the flowchart and / or block diagram.

[0048] These computer program instructions can also be stored on a computer-readable medium that can direct a computer or other programmable data processing apparatus or other devices to function in a particular manner, such that the instructions stored on the computer-readable medium produce an article of manufacture including instructions for implementing the functions / steps specified in the block or blocks of the flowchart and / or block diagram.

[0049] The computer program instructions can also be stored on a computer, other programmable data processing apparatus, or other devices, so that the computer, other programmable data processing apparatus, or other devices execute a series of processing steps to generate a process that is executed on the computer, such that the instructions executed on the computer or other programmable device produce a method for implementing the functions / steps specified in the block or blocks of the flowchart and / or block diagram. BRIEF DESCRIPTION OF THE DRAWINGS

[0050] Further advantages and features will be derived from the following description in conjunction with the drawings. In the drawings:

[0051] Figure 1 A motor vehicle equipped with an ultrasonic measurement unit is shown.

[0052] Figure 2A The transmission and reception operations on the first channel of the ultrasonic measurement unit are shown.

[0053] Figure 2B The transmission operation of the ultrasonic measurement unit on the second channel and the reception operations on the first and second channels are shown.

[0054] Figure 3 A block diagram of the components of the ultrasonic measurement unit is shown.

[0055] Figure 4 A block diagram of the components of the ultrasonic measurement unit is shown.

[0056] Figure 5A flowchart showing a method of operating an ultrasonic measurement unit,

[0057] Figure 6 A time graph showing the ultrasonic amplitude measured on an ultrasonic transducer on a channel, and

[0058] Figure 7 A schematic diagram showing the time division of a measurement period. Detailed implementation

[0059] Especially in the field of automotive technology, ultrasonic measurement systems are increasingly used to detect obstacles and measure their distances. Figure 2A and 2B Illustrates the alternating transmission of ultrasonic signals 210, 220 on different channels and the reception of the echoes 212, 214, 222 of the transmitted ultrasonic signals 210, 220. Figure 3 The ultrasonic measurement unit 300 shown or Figure 4 The ultrasonic measurement unit 400 shown can be used for this purpose. The ultrasonic measurement units 300, 400 can implement Figure 5 The method 500 for operating an ultrasonic measurement unit shown, in order to detect objects 202, 204 near a motor vehicle 100, 200, for example. For this purpose, ultrasonic signals 210, 220 can be transmitted in the direction of the objects 202, 204, and their echoes 212, 214, 222 are received and analyzed according to the reception period and the channel.

[0060] Figure 1 Shows a motor vehicle 100, such as a ground motor vehicle, such as a passenger car, a goods transport vehicle (van, truck) or an agricultural vehicle. In Figure 1 In a non-limiting example, the motor vehicle 100 has an electronic control unit 102, which can implement the functions of the control unit and the analysis unit of the ultrasonic measurement unit as its functions. To illustrate these functions, the control unit 102 can, for example, have a dedicated chip in which program instructions are permanently programmed, and the chip executes these instructions to enable the control unit 102 to implement the functions of the control unit and the analysis unit; or the control unit 102 can, for example, have a general-purpose processor, and when the control unit 102 is initialized, the processor loads program instructions from a memory, and the processor executes these instructions to enable the control unit 102 to execute the functions of the control unit and the analysis unit. The power supply 110 (such as a battery and / or an alternator) of the motor vehicle 100 can provide electrical energy so that the components connected to the control unit 102 described below can be used.

[0061] The motor vehicle 100 has a plurality of ultrasonic transducers 130 which are connected via, for example, an analog or digital electrical wiring system 112 to an interface of the control unit 102. The control unit 102 can perform the functions of the control unit via the wiring system 112 to control one or more ultrasonic transducers 130 to alternately transmit ultrasonic signals on different channels. The echoes of the transmitted ultrasonic signals received by one or more ultrasonic transducers 130 can be converted by the ultrasonic transducers 130 into electrical signals and transmitted via the wiring system 112 to the control unit 102. The control unit 102 can perform the functions of the analysis unit to analyze the signals corresponding to the received echoes, thereby detecting at least one object that generates the echoes.

[0062] Other components of the motor vehicle 100 can be connected to the interface of the control unit 102. For example, a bus system 114 (such as Controller Area Network, CAN) can connect the steering controller 104, the human-machine interface 106 (such as a touch screen display) and the brake controller 108 to the control unit 102. The control unit 102 can be configured to generate and / or adjust signals for the steering controller 104, the human-machine interface 106 and / or the brake controller 108 based on the ultrasonic echo analysis results provided by the analysis unit, and / or to control and / or adjust the functions of the control unit and / or the analysis unit in response to a user's interaction with the human-machine interface 106. In another example, for example, analog or digital electrical wiring systems 116, 118 can connect a set of operating elements 124 and a set of output units 126 (such as speakers) to the control unit 102. The control unit 102 can be configured to generate and / or adjust signals for the output unit 126 based on the ultrasonic echo analysis results provided by the analysis unit, and / or to control and / or adjust the functions of the control unit and / or the analysis unit in response to a user's interaction with the operating elements 124.

[0063] FIG. 2 shows a schematic snapshot of a motor vehicle 200 having an ultrasonic measurement unit at different time points when transmitting ultrasonic signals 210, 220 and receiving the echoes 212, 214, 222 of the transmitted ultrasonic signals. In Figure 2A this case, the ultrasonic measurement unit has caused the ultrasonic transducer to transmit a first ultrasonic signal 210 on the first channel, for example, at a first frequency. There are two obstacles within the detection range, and the ultrasonic measurement unit can receive the echoes of the ultrasonic signals from these obstacles via one or more ultrasonic transducers within the range specified by the measurement sensitivity and (if applicable) within the duration of the measurement cycle. The distance of the obstacle 204 from the motor vehicle 200 is farther than that of the obstacle 202.

[0064] In Figure 2AAt the time point shown, the first ultrasonic signal 210 has propagated to the nearest obstacle 202 and the farthest obstacle 204, and the first echo 212 of the first ultrasonic signal 210 reflected back from the nearest obstacle 202 towards the motor vehicle 200 has just reached one of the ultrasonic transducers. Therefore, at Figure 2A the time point shown, the analysis unit can detect the obstacle 202 by analyzing the signal corresponding to the first echo 212 of the first ultrasonic signal 210. At Figure 2A this time, no ultrasonic echo has been reflected back from the obstacle 204 towards the motor vehicle 200.

[0065] Figure 2B Fig. shows the motor vehicle 200 and the obstacles 202, 204 at a later moment. At Figure 2B this time, the ultrasonic measurement unit has emitted a second ultrasonic signal 220 on the second channel (for example, at a second frequency) using the same ultrasonic transducer. The two obstacles 202, 204 are still within the detection range of the ultrasonic measurement unit, and the distance between the obstacle 204 and the motor vehicle 200 is still greater than the distance between the obstacle 202 and the motor vehicle 200. At Figure 2B the moment shown, the second ultrasonic signal 220 has been reflected back from the nearest obstacle 202 (echo 222). Therefore, at Figure 2B the moment shown, the analysis unit can detect the obstacle 202 by analyzing the signal corresponding to the echo 222.

[0066] At Figure 2B this time, the ultrasonic signal 210 from the obstacle 204 has also been reflected back as the second echo 214. Therefore, at Figure 2B the moment shown, the analysis unit can detect the obstacle 204 by analyzing the signal corresponding to the second echo 214. This principle described for a single ultrasonic transducer can also be applied accordingly to multiple ultrasonic transducers, as schematically shown in the form of a triangle in Figure 2A and Figure 2B .

[0067] Figure 3A block diagram of an exemplary ultrasonic measurement unit 300 is shown. The ultrasonic measurement unit 300 has a control unit 310 and an analysis unit 320. The control unit 310 has an output terminal through which the control unit 310 can transmit a signal 312 to one or more ultrasonic transducers, and this signal causes the one or more ultrasonic transducers to alternately transmit ultrasonic signals on different channels respectively. The control unit 310 may have an interface for connecting to a signal line 311, and the control unit 310 can exchange signals with other units through the signal line 311 (for example, signals for controlling and / or configuring the functions of the control unit 310, signals for transmitting the output of the control unit 310, such as status information, etc.). The control unit 310 may also have an interface for connecting to a signal line 313, and the control unit 310 can exchange signals with the analysis unit 320 through this signal line (for example, time synchronization signals, trigger signals or other control signals). The analysis unit 320 has an input terminal through which the analysis unit 320 can receive a signal 314 from one or more ultrasonic transducers, and this signal corresponds to the ultrasonic signals received by the one or more ultrasonic transducers (for example, the echoes of the ultrasonic signals). The analysis unit 320 may also have an interface for connecting to a signal line 316, and the analysis unit 320 can exchange signals with other units through the signal line 316 (for example, signals for controlling and / or configuring the functions of the analysis unit 320, signals for transmitting the output of the analysis unit 320, such as status information and / or obstacle information detected by the received signals, for example, the distance to the obstacle closest to the transmitting ultrasonic transducer, etc.). The analysis unit 320 may also have an interface for connecting to a signal line 313, and the analysis unit 320 can exchange signals with the control unit 310 through this signal line (for example, time synchronization signals, trigger signals or other control signals).

[0068] Figure 4 A block diagram of an ultrasonic measurement unit 400 is shown. The ultrasonic measurement unit 400 has a control unit 410, an analysis unit 420, and one or more ultrasonic transducers 415, such as Figure 2A and Figure 2B the ultrasonic transducers used in Figure 3 (where the reference numerals 310, 320, 311, 313, and 316).

[0069] The analysis unit 420 has an input through which the analysis unit 420 can receive a signal 414 from one or more ultrasonic transducers 415, which corresponds to the ultrasonic signal received by the ultrasonic transducer 415 (e.g., the echo of the ultrasonic signal). The one or more ultrasonic transducers 415 may have an interface for receiving a signal 412 from the control unit 410 and transmitting the signal 414 to the analysis unit 420, a transmitting device for generating an ultrasonic signal based on the received signal 412, and a receiving device for amplifying, for example, the received ultrasonic signal and generating a signal 414 based on the received ultrasonic signal.

[0070] Figure 5 A flowchart showing the steps of a method 500 that can be implemented by the ultrasonic measurement unit of the present disclosure is shown. The method 500 provides that the ultrasonic measurement unit controls 502 one or more ultrasonic transducers through its control unit to alternately transmit ultrasonic signals on different channels, respectively. The method 500 further includes a step 504, in which the analysis unit of the ultrasonic measurement unit analyzes the signal formed by the echoes generated by the ultrasonic signals alternately transmitted on different channels to detect at least one object causing the echoes. To successfully execute step 504, step 502 needs to have been executed at least once previously to generate potential echoes for the analysis unit to analyze. In addition, steps 502 and 504 can be executed, repeated, and / or performed in parallel in time in any order.

[0071] Figure 6 An exemplary time characteristic diagram showing the signal amplitude measured by the ultrasonic transducer at the start of the single-channel transmission and reception period is shown. The time and duration values Figure 6 mentioned in relation are for illustrative purposes only and should in no way be construed as provisions limiting the present invention. The transmission and reception period begins with exciting the vibration unit (e.g., diaphragm) of the ultrasonic transducer at time t = 0 to transmit an ultrasonic signal. The excitation signal output by the control unit of the ultrasonic measurement unit to excite the vibration unit from t = 0 by the excitation unit (e.g., piezoelectric element) of the ultrasonic transducer terminates after a predefined excitation duration 602 (e.g., 250 µs). After the excitation signal terminates, the vibration unit continues to vibrate for a reverberation duration 604 with a known nominal value (e.g., 1 ms) until the measured amplitude drops below a known or continuously updated noise level. The sum of the excitation duration 602 and the reverberation duration 604 constitutes the transmission period 606 (e.g., 1.25 ms) of a given channel. After the transmission period 606 is the reception period 610, the duration of which (e.g., 30 ms) is very long compared to the duration of the transmission period, so Figure 6 the end time thereof is not shown. During the reception period 610, no transmission operation is performed on any channel implemented by the ultrasonic measurement unit. The transmission period 606 and the reception period 610 are collectively referred to as the transmission and reception period.

[0072] At a time after the end of the transmission period 606 (shown in the figure as the delay time 608 starting from t = 0), the first echo of the ultrasonic signal transmitted during the transmission period 606 arrives at the ultrasonic transducer. It causes an increase in amplitude, and the analysis unit of the ultrasonic measurement unit detects this increase in amplitude, for example, by comparing it with a predefined threshold representing the maximum acceptable noise level. Based on the delay Δt time 608 and the speed of sound c, the analysis unit can determine the distance to the obstacle corresponding to the echo received after the delay time 608 .

[0073] Figure 7 A timeline is shown, on which different time periods of the measurement cycle 700 are marked. The measurement cycle 700 is divided into a first transmission and reception period 710 and a second transmission and reception period 720. In Figure 7 the example, but without limiting generality, the first transmission and reception period 710 and the second transmission and reception period 720 have the same length. The first transmission and reception period 710 is divided into a first transmission period 712 and a first reception period 714; the second transmission and reception period 720 is divided into a second transmission period 722 and a second reception period 724. In Figure 7 the example, but without limiting generality, the first transmission period 712 and the second transmission period 722 have the same length, and the first reception period 714 and the second reception period 724 have the same length. In another non - limiting example, the duration of the measurement cycle 700 is 50 ms, divided into a first transmission period of 1.4 ms, a first reception period of 23.6 ms, a second transmission period of 1.4 ms, and a second reception period of 23.6 ms

[0074] The measurement cycle 700 can be repeated with the same or different durations of individual transmission and reception periods. The ultrasonic measurement unit implementing the measurement cycle 700 is configured to control the ultrasonic transducer to alternately transmit ultrasonic signals on different channels. In Figure 7 the example shown, the ultrasonic measurement unit, through its control unit, controls the ultrasonic transducer to transmit a first ultrasonic signal on the first channel during the first transmission period 712 and to transmit a second ultrasonic signal on the second channel during the second transmission period 722

[0075] With Figure 6Similar to the description, in the first reception period 714, the analysis unit of the ultrasonic measurement unit can analyze, on the first channel, a signal corresponding to the echo of the first ultrasonic signal transmitted during the first transmission period 712 and received by the ultrasonic transducer, in order to detect one or more objects that generate echoes in the short range. Optionally, the analysis unit also analyzes, in the first reception period 714, a signal corresponding to the echo of the second ultrasonic signal transmitted on the second channel during the second transmission period 722 of an earlier measurement cycle 700 and received by the ultrasonic transducer, in order to detect one or more other objects that generate echoes in the first long range. Also optionally, the analysis unit further analyzes, in the first reception period 714, a signal corresponding to the echo of the first ultrasonic signal transmitted on the first channel during the first transmission period 712 of the earlier measurement cycle 700 and received by the ultrasonic transducer, in order to detect one or more other objects that generate echoes in the second long range that is farther from the transmitting ultrasonic transducer than the first long range. The analysis unit can distinguish the echo on the same channel from the earlier measurement cycle 700 and the echo on the same channel of the ultrasonic signal transmitted during the current measurement cycle 700 according to the known time characteristics of the maximum amplitude of the ultrasonic echo.

[0076] In the second reception period 724, the analysis unit of the ultrasonic measurement unit analyzes, on the second channel, a signal corresponding to the echo of the second ultrasonic signal transmitted during the second transmission period 722 and received by the ultrasonic transducer, in order to detect one or more objects that generate echoes in another short range. In addition, the analysis unit analyzes, in the second reception period 724, a signal corresponding to the echo of the first ultrasonic signal transmitted on the first channel during the first transmission period 712 of the current measurement cycle 700 and received by the ultrasonic transducer, in order to detect one or more other objects that generate echoes in another first long range. Optionally, the analysis unit also analyzes, in the second reception period 724, a signal corresponding to the echo of the second ultrasonic signal transmitted on the second channel during the second transmission period 722 of the earlier measurement cycle 700 and received by the ultrasonic transducer, in order to detect one or more other objects that generate echoes in another second long range. A new measurement cycle 700 with another first transmission period 712 can start immediately after the second reception period 724 ends.

[0077] It should be noted that the embodiments of the present invention described herein can be combined with each other in any way as long as there is no technical obstacle to the combination of two specific embodiments.

[0078] List of reference numerals

[0079] 100 Motor vehicle

[0080] 102 Control unit

[0081] 104 Steering controller

[0082] 106 Human - machine interface

[0083] 108 Brake controller

[0084] 110 Power supply

[0085] 112 Line system

[0086] 114 Bus system

[0087] 116 Line system

[0088] 118 Line system

[0089] 124 Operating element

[0090] 126 Output unit

[0091] 130 Ultrasonic transducer

[0092] 200 Motor vehicle

[0093] 202 Obstacle

[0094] 204 Obstacle

[0095] 210 First ultrasonic signal

[0096] 212 First echo of the first ultrasonic signal

[0097] 214 Second echo of the first ultrasonic signal

[0098] 220 Second ultrasonic signal

[0099] 222 Echo of the second ultrasonic signal

[0100] 300 Ultrasonic measurement unit

[0101] 310 Control unit

[0102] 311 Signal line

[0103] 312 Output signal

[0104] 313 Signal line

[0105] 314 Input signal

[0106] 316 Signal line

[0107] 320 Analysis unit

[0108] 400 Ultrasonic measurement unit

[0109] 410 Control unit

[0110] 411 Signal line

[0111] 412 Output signal

[0112] 413 Signal line

[0113] 414 Input signal

[0114] 415 Ultrasonic transducer

[0115] 416 Signal line

[0116] 420 Analysis unit

[0117] 500 Operating method of ultrasonic measurement unit

[0118] 502 Transmission control

[0119] 504 Detection and analysis

[0120] 602 Excitation time

[0121] 604 Reverberation time

[0122] 606 Transmission period

[0123] 608 Delay time

[0124] 610 Reception period

[0125] 700 Measurement cycle

[0126] 710 First transmission and reception period

[0127] 712 First transmission period

[0128] 714 First reception period

[0129] 720 Second transmission and reception period

[0130] 722 Second transmission period

[0131] 724 Second reception period

Claims

1. An ultrasonic measurement unit (300, 400), especially for use in a vehicle (100, 200), comprising a control unit (310, 410) and an analysis unit (320, 420), wherein the control unit (310, 410) is configured to control (502) ultrasonic transducers (130, 415) to alternately transmit ultrasonic signals (210, 220) on different channels, the analysis unit (320, 420) is configured to analyze (504) the echoes (212, 214, 222) generated by the ultrasonic signals (210, 220) on the channels to detect at least one object (202, 204) causing the echoes.

2. The ultrasonic measurement unit (300, 400) according to claim 1, wherein the control (502) and the analysis (504) are performed within a measurement cycle (700), and the measurement cycle (700) is repeatedly executed cyclically.

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

4. The ultrasonic measurement unit (300, 400) according to claim 3, wherein the analysis (504) at least considers the echoes (212) generated on the first channel between the transmissions of the two ultrasonic signals (210, 220), and the analysis considers the echoes (212, 214, 222) generated on the first channel and the second channel after the transmission of the second ultrasonic signal (220).

5. The ultrasonic measurement unit (300, 400) according to claim 3 or 4, wherein a maximum spatial measurement distance of the ultrasonic measurement unit (300, 400) is defined, and the length of the measurement cycle (700) is set such that within the measurement cycle (700), the echoes (212, 214) generated by an object (202, 204) located at the maximum measurement distance and generated by the first ultrasonic signal (210) can be detected.

6. The ultrasonic measurement unit (300, 400) according to any one of the preceding claims 2 - 5, wherein the analysis unit (320, 420) is configured to continuously analyze the echoes (212, 214, 222) generated by the ultrasonic signals (210, 220) on all channels within the measurement cycle (700).

7. The ultrasonic measurement unit (300, 400) according to any one of the preceding claims, wherein, The analysis unit (320, 420) is configured to receive the echoes (212, 214, 222) from the same ultrasonic transducers (130, 415) that emit the ultrasonic signals (210, 220).

8. The ultrasonic measurement unit (300, 400) according to any one of the preceding claims 2 - 7, wherein the different channels include at least three channels, and within the measurement cycle (700), the transmissions of consecutive ultrasonic signals (210, 220) are performed at different time intervals, and the different time intervals for the periodic repeated execution of the measurement cycle (700) are constant.

9. The ultrasonic measurement unit (300, 400) according to any one of the preceding claims 2-7, wherein during the periodic and repeated execution of the measurement cycle (700), at least in some of the measurement cycles (700), the transmission of the continuous ultrasonic signals (210, 220) is carried out at different time intervals.

10. The ultrasonic measurement unit (300, 400) according to any one of the preceding claims, further comprising an ultrasonic transducer (415), wherein the ultrasonic transducer (415) is configured to receive the echoes (212, 214, 222) generated by the ultrasonic signals (210, 220) on all channels and transmit them to the analysis unit (320, 420).

11. A method (500) for operating an ultrasonic measurement unit (300, 400), in particular for a vehicle (100, 200), wherein the ultrasonic measurement unit (300, 400) comprises a control unit (310, 410) and an analysis unit (320, 420), and wherein the method (500) comprises: controlling (502) an ultrasonic transducer (130, 415) by means of the control unit (310, 410) to alternately transmit ultrasonic signals (210, 220) on different channels, analyzing (504), by means of the analysis unit (320, 420), the echoes (212, 214, 222) generated by the ultrasonic signals (210, 220) on the channels to detect at least one object (202, 204) causing the echoes (212, 214, 222).

12. A computer program product, in particular a computer-readable storage medium, wherein the computer program product comprises computer-executable code, and wherein the code can be executed by at least one processor of a computer device (102) to cause the computer device (102) to execute the method (500) according to claim 11.

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