Classifications

• • G—PHYSICS
  • G01—MEASURING; TESTING
  • G01S—RADIO DIRECTION-FINDING; RADIO NAVIGATION; DETERMINING DISTANCE OR VELOCITY BY USE OF RADIO WAVES; LOCATING OR PRESENCE-DETECTING BY USE OF THE REFLECTION OR RERADIATION OF RADIO WAVES; ANALOGOUS ARRANGEMENTS USING OTHER WAVES
  • G01S15/00—Systems using the reflection or reradiation of acoustic waves, e.g. sonar systems
  • G01S15/02—Systems using the reflection or reradiation of acoustic waves, e.g. sonar systems using reflection of acoustic waves
  • G01S15/06—Systems determining the position data of a target
  • G01S15/08—Systems for measuring distance only
  • G01S15/10—Systems for measuring distance only using transmission of interrupted, pulse-modulated waves
  • G01S15/101—Particularities of the measurement of distance
• • G—PHYSICS
  • G01—MEASURING; TESTING
  • G01S—RADIO DIRECTION-FINDING; RADIO NAVIGATION; DETERMINING DISTANCE OR VELOCITY BY USE OF RADIO WAVES; LOCATING OR PRESENCE-DETECTING BY USE OF THE REFLECTION OR RERADIATION OF RADIO WAVES; ANALOGOUS ARRANGEMENTS USING OTHER WAVES
  • G01S15/00—Systems using the reflection or reradiation of acoustic waves, e.g. sonar systems
  • G01S15/02—Systems using the reflection or reradiation of acoustic waves, e.g. sonar systems using reflection of acoustic waves
  • G01S15/06—Systems determining the position data of a target
  • G01S15/08—Systems for measuring distance only
  • G01S15/10—Systems for measuring distance only using transmission of interrupted, pulse-modulated waves
  • G01S15/102—Systems for measuring distance only using transmission of interrupted, pulse-modulated waves using transmission of pulses having some particular characteristics
  • G01S15/104—Systems for measuring distance only using transmission of interrupted, pulse-modulated waves using transmission of pulses having some particular characteristics wherein the transmitted pulses use a frequency- or phase-modulated carrier wave
• • G—PHYSICS
  • G01—MEASURING; TESTING
  • G01S—RADIO DIRECTION-FINDING; RADIO NAVIGATION; DETERMINING DISTANCE OR VELOCITY BY USE OF RADIO WAVES; LOCATING OR PRESENCE-DETECTING BY USE OF THE REFLECTION OR RERADIATION OF RADIO WAVES; ANALOGOUS ARRANGEMENTS USING OTHER WAVES
  • G01S15/00—Systems using the reflection or reradiation of acoustic waves, e.g. sonar systems
  • G01S15/02—Systems using the reflection or reradiation of acoustic waves, e.g. sonar systems using reflection of acoustic waves
  • G01S15/06—Systems determining the position data of a target
  • G01S15/08—Systems for measuring distance only
  • G01S15/10—Systems for measuring distance only using transmission of interrupted, pulse-modulated waves
  • G01S15/102—Systems for measuring distance only using transmission of interrupted, pulse-modulated waves using transmission of pulses having some particular characteristics
  • G01S15/107—Systems for measuring distance only using transmission of interrupted, pulse-modulated waves using transmission of pulses having some particular characteristics using frequency agility of carrier wave
• • G—PHYSICS
  • G01—MEASURING; TESTING
  • G01S—RADIO DIRECTION-FINDING; RADIO NAVIGATION; DETERMINING DISTANCE OR VELOCITY BY USE OF RADIO WAVES; LOCATING OR PRESENCE-DETECTING BY USE OF THE REFLECTION OR RERADIATION OF RADIO WAVES; ANALOGOUS ARRANGEMENTS USING OTHER WAVES
  • G01S15/00—Systems using the reflection or reradiation of acoustic waves, e.g. sonar systems
  • G01S15/02—Systems using the reflection or reradiation of acoustic waves, e.g. sonar systems using reflection of acoustic waves
  • G01S15/06—Systems determining the position data of a target
  • G01S15/08—Systems for measuring distance only
  • G01S15/32—Systems for measuring distance only using transmission of continuous waves, whether amplitude-, frequency-, or phase-modulated, or unmodulated
• • G—PHYSICS
  • G01—MEASURING; TESTING
  • G01S—RADIO DIRECTION-FINDING; RADIO NAVIGATION; DETERMINING DISTANCE OR VELOCITY BY USE OF RADIO WAVES; LOCATING OR PRESENCE-DETECTING BY USE OF THE REFLECTION OR RERADIATION OF RADIO WAVES; ANALOGOUS ARRANGEMENTS USING OTHER WAVES
  • G01S15/00—Systems using the reflection or reradiation of acoustic waves, e.g. sonar systems
  • G01S15/02—Systems using the reflection or reradiation of acoustic waves, e.g. sonar systems using reflection of acoustic waves
  • G01S15/06—Systems determining the position data of a target
  • G01S15/08—Systems for measuring distance only
  • G01S15/32—Systems for measuring distance only using transmission of continuous waves, whether amplitude-, frequency-, or phase-modulated, or unmodulated
  • G01S15/325—Systems for measuring distance only using transmission of continuous waves, whether amplitude-, frequency-, or phase-modulated, or unmodulated using transmission of coded signals, e.g. of phase-shift keyed [PSK] signals
• • G—PHYSICS
  • G01—MEASURING; TESTING
  • G01S—RADIO DIRECTION-FINDING; RADIO NAVIGATION; DETERMINING DISTANCE OR VELOCITY BY USE OF RADIO WAVES; LOCATING OR PRESENCE-DETECTING BY USE OF THE REFLECTION OR RERADIATION OF RADIO WAVES; ANALOGOUS ARRANGEMENTS USING OTHER WAVES
  • G01S15/00—Systems using the reflection or reradiation of acoustic waves, e.g. sonar systems
  • G01S15/87—Combinations of sonar systems
• • G—PHYSICS
  • G01—MEASURING; TESTING
  • G01S—RADIO DIRECTION-FINDING; RADIO NAVIGATION; DETERMINING DISTANCE OR VELOCITY BY USE OF RADIO WAVES; LOCATING OR PRESENCE-DETECTING BY USE OF THE REFLECTION OR RERADIATION OF RADIO WAVES; ANALOGOUS ARRANGEMENTS USING OTHER WAVES
  • G01S15/00—Systems using the reflection or reradiation of acoustic waves, e.g. sonar systems
  • G01S15/88—Sonar systems specially adapted for specific applications
  • G01S15/93—Sonar systems specially adapted for specific applications for anti-collision purposes
  • G01S15/931—Sonar systems specially adapted for specific applications for anti-collision purposes of land vehicles
• • G—PHYSICS
  • G01—MEASURING; TESTING
  • G01S—RADIO DIRECTION-FINDING; RADIO NAVIGATION; DETERMINING DISTANCE OR VELOCITY BY USE OF RADIO WAVES; LOCATING OR PRESENCE-DETECTING BY USE OF THE REFLECTION OR RERADIATION OF RADIO WAVES; ANALOGOUS ARRANGEMENTS USING OTHER WAVES
  • G01S7/00—Details of systems according to groups G01S13/00, G01S15/00, G01S17/00
  • G01S7/52—Details of systems according to groups G01S13/00, G01S15/00, G01S17/00 of systems according to group G01S15/00
  • G01S7/523—Details of pulse systems
  • G01S7/526—Receivers
  • G01S7/527—Extracting wanted echo signals
• • G—PHYSICS
  • G01—MEASURING; TESTING
  • G01S—RADIO DIRECTION-FINDING; RADIO NAVIGATION; DETERMINING DISTANCE OR VELOCITY BY USE OF RADIO WAVES; LOCATING OR PRESENCE-DETECTING BY USE OF THE REFLECTION OR RERADIATION OF RADIO WAVES; ANALOGOUS ARRANGEMENTS USING OTHER WAVES
  • G01S7/00—Details of systems according to groups G01S13/00, G01S15/00, G01S17/00
  • G01S7/52—Details of systems according to groups G01S13/00, G01S15/00, G01S17/00 of systems according to group G01S15/00
  • G01S7/52001—Auxiliary means for detecting or identifying sonar signals or the like, e.g. sonar jamming signals

Definitions

• the invention relates to a method for operating an ultrasonic sensor, as well as a distance measuring device with at least one ultrasonic sensor, which is operated according to the inventive method.
• Ultrasonic-based measuring systems are used to measure a distance to an object located in front of an ultrasonic sensor.
• the sensors used are based on the pulse / echo method.
• an ultrasonic sensor emits an ultrasonic pulse and measures the reflection of the ultrasonic pulse (echo) caused by an object.
• the distance between the ultrasonic sensor and the object is calculated using the measured echo time and the speed of sound.
• the ultrasonic sensor acts as transmitter to receiver.
• Known applications are, for example
• ultrasonic sensors In known distance measuring devices on vehicles typically 4 to 6 ultrasonic sensors are used in the front and / or rear bumper. To capture the environment as quickly as possible, it is helpful if all the ultrasonic sensors on the bumper send at the same time and thus the information can be processed in parallel. This can special
• Ultrasonic sensors are chosen that differ.
• DE 10 2007 029 959 A1 discloses an ultrasound-based measuring system for detecting an environment. It is provided that distance measurements can be made by means of ultrasonic waves. At two
• Ultrasonic signals are coded for distinctness.
• the processing of the signals in the receive path can be done, for example, by the received signals through a matched filter
• matched filter (so-called "matched filter”) are filtered.
• deal codes are characterized in that the codes are mutually orthogonal, i. that the matched filters of the codes act in such a way that they largely suppress the foreign codes. In practice, however, complete suppression by the matched filters is hardly possible.
• the invention is therefore based on the object to provide a method for operating an ultrasonic sensor, in which the influence of disturbances, which can be caused in particular by ultrasonic signals of other vehicles, is reduced.
• the invention is based on the idea of receiving signals from one
• operated ultrasonic sensor are sent to encode.
• the coding takes place either by means of randomly selected codes or by means of randomly selected code sequences.
• a change of the codes is provided after each measuring cycle. The measuring cycle is a complete run until the next transmission operation of the same sensor.
• Excitation pulse is excited to mechanical vibrations, whereby a measurement signal is sent through the transducer,
• measurement cycles executed sequentially in time, wherein the frequency profile of an excitation pulse in each measurement cycle is selected at random or in a predetermined order from a group of predetermined frequency profiles.
• each code corresponds to a specific excitation pattern, it being provided that after each excitation for a temporally following, renewed excitation another excitation pattern, so another code is used.
• a code from a given group of codes can be randomly selected in each measuring cycle.
• the order in which the codes are selected from the given group of codes is fixed.
• the determined object information from at least two measuring cycles are compared with each other and depending on the result of the comparison, a fault is detected.
• a malfunction is understood as meaning, in particular, a faulty measurement which may be caused by an ultrasound signal from a foreign ultrasound sensor, which is part of a distance measuring system of a foreign vehicle, for example.
• the emission time is stochastically jittered within a respective measurement cycle Aussendezeittician. This means that the time at which the respective excitation pulse is applied to the transducer, relative to a
• Start time of the measurement cycle is shifted by a randomly selected period.
• This time period is particularly small in comparison to the total duration of the respective measurement cycle and may be, for example, in the range of 1 to 10 ms, wherein the total duration of the measurement cycle may be, for example, about 40 ms.
• This embodiment is particularly in the second variant of
• Invention is advantageous because in the second variant, although the probability of synchronization is reduced, but it can still interfere with the deterministic order of the selected excitation pattern (codes). This effect can be caused by the stochastic jitter of the
• the excitation patterns (codes) of the group selected from are designed such that they suppress one another as far as possible. This is achieved, for example, by having the codes of the group orthogonal to each other.
• the duration of a first excitation pulse of a first measurement cycle differs from the duration of a second excitation pulse of a second measurement cycle, wherein the second measurement cycle follows the time of the first measurement cycle.
• the second measuring cycle can directly follow the first measuring cycle. This means that no further signal is transmitted between the first and the second measuring cycle, but there may be a pause between the first and the second measuring cycle in which no excitation takes place.
• the second Measuring cycle not immediately follow the first measurement cycle, but between the first and the second measurement cycle, a further excitation.
• the amplitude of a first excitation pulse of a first measurement cycle may differ from the amplitude of a second excitation pulse of a second measurement cycle. This causes the
• the second measuring cycle can directly follow the first measuring cycle. This means that no further signal is transmitted between the first and the second measuring cycle, but there may be a pause between the first and the second measuring cycle in which no excitation takes place.
• the second measurement cycle can not follow directly on the first measurement cycle, but between the first and the second measurement cycle another
• the excitation pulses are preferably designed as frequency-modulated pulses.
• a frequency-modulated excitation pulse is to be understood as meaning any excitation pulse whose frequency changes during the pulse duration. In this case, continuous or discontinuous changes in the frequency can be provided. Alternatively or additionally, it is also possible to use pulses with a continuously constant excitation frequency.
• Excitation pulses by a, in particular linear, frequency response, modulated, in particular in a frequency range between 40 kHz and 60 kHz. This means that the frequency of the respective excitation pulse rises steadily and in particular linearly from a starting frequency or drops until an end frequency is reached. Such an excitation is also referred to as "chirp.”
• the start and end frequencies are preferably selected from the frequency range from 40 kHz to 60 kHz.
• a matched filter also referred to as an optimal filter or correlation filter
• This can be done in an advantageous manner the signal-to-noise ratio can be improved by using the known waveform of the excitation pulse in the selection of the filter in a known manner.
• object information is determined with higher accuracy.
• Measuring cycles calculates a probability that a detected object is actually present or that there is a faulty measurement. This can be particularly efficient suppression of interference by ultrasonic signals from other vehicles in the sense of incorrect measurements C.False Positives ”) can be achieved.
• Ultrasonic sensor provided at least four measuring cycles, wherein in each measuring cycle, the transducer of the ultrasonic sensor is driven with an excitation pulse with a different excitation pattern or frequency response, either randomly an excitation pattern from a group of possible excitation patterns is selected in each measurement cycle, or it is
• Excitation pattern selected from a group according to a given order.
• a distance measuring device in particular for a motor vehicle, which comprises at least one ultrasonic sensor which is operated according to one of the methods described above.
• a distance measuring device which comprises a plurality of ultrasonic sensors, which are operated in accordance with a method as described above, wherein the ultrasonic sensors on a
• Body part of a motor vehicle are arranged in a row.
• the ultrasonic sensors are operated in such a way that ultrasonic sensors arranged adjacent to one another have measurement cycles which do not overlap in time.
• Figure 1 shows schematically a distance measuring device with a plurality of ultrasonic sensors according to an embodiment of the invention.
• FIG. 2 shows four diagrams of possible frequency profiles for excitation pulses.
• FIG. 3 shows a table with a sequence of measuring cycles for different ultrasonic sensors of a distance measuring device with a plurality of ultrasonic sensors according to an embodiment of the invention.
• Figure 1 shows schematically in plan view a motor vehicle 20 with a
• the ultrasonic sensors 1 to 12 are part of a distance measuring device for detecting the environment of the motor vehicle 20. Furthermore, an object 19 to be detected by means of the ultrasonic sensors is shown in the surroundings of the motor vehicle 20. It may be, for example, a traffic obstruction, such as a bucket, a street sign or a lantern as well as another vehicle.
• Each of the ultrasonic sensors 1 to 12 has an electroacoustic transducer, which is excited by a frequency-modulated excitation pulse to mechanical vibrations, whereby a measuring signal 30 is emitted through the transducer.
• the invention is not limited to that
• Ultrasonic sensors are arranged at the rear or at the front of a motor vehicle 20. Alternatively or additionally, further ultrasonic sensors For example, in the area of the sides, in particular the doors of the
• Motor vehicle 20 may be arranged.
• a transmission cone of a transmitted measuring signal 30 and a directional arrow 31, which indicates the transmission direction, are shown by way of example. It can be seen that the transmission cone hits the object 19, so that the measurement signal 30 is partially reflected by the object 19 in the direction of the ultrasound sensor 3 in a second transmission cone (echo) 32.
• the ultrasonic sensor 3 registers the reflection 32 and determines the elapsed time between transmission of the transmission pulse and reception of the reflection. From the elapsed time can be at a known signal speed, for example, the speed of sound in air of about 343 m / s, calculate the distance of the object 19 of the ultrasonic sensor 3.
• the ultrasonic sensor 3 can not only receive the measurement signals 32 reflected by the object 19 but also ultrasonic signals 33 emanating from another sound source 21, for example a foreign vehicle. This can lead to erroneous measurement results, or it will be of the
• the ultrasound sensor 3 is operated in such a way that several measuring cycles are carried out successively. In each measurement cycle, another excitation pulse is used to excite the
• electroacoustic transducer used as in the previous measuring cycle, wherein in successive time measuring cycles, the respective frequency response of the excitation pulses differs. It is the
• Frequency response of an excitation pulse in each measurement cycle selected from a group of predetermined frequency curves randomly or in a predetermined order.
• frequency modulated excitation pulses codes
• the excitation frequency is linearly changed from a start frequency to a target frequency during the excitation pulse, but the invention is not limited to this type of frequency modulation, it is also other excitation patterns Furthermore, for example, constant frequency profiles can be used, at least in sections, for the person skilled in the art, for which a variety of further design possibilities are known.
• each of the ultrasonic sensors 1 to 12 to vary the excitation patterns (codes) from shot to shot in such a way that the frequency response of the excitation pulses takes place in successively executed measuring cycles
• the frequency response of an excitation pulse in each measurement cycle from a group of predetermined frequency characteristics is selected randomly or in a predetermined order.
• excitation patterns for the frequency-modulated excitation pulses are shown in the figure in diagrams 41-44. In each case the frequency is plotted against time. These excitation patterns preferably form a group from which an excitation pattern is selected as the excitation pulse for the transducer of an ultrasonic sensor 1 to 12 in each measurement cycle. The selection can be done either by chance or after a predetermined
• the frequency fo is in this example 48 kHz, the pulse duration T is 1.6 ms.
• the group of possible excitation patterns contains the following excitation patterns (codes):
• excitation patterns can now be performed in each of the ultrasonic sensors in a specific or random order, wherein in an ultrasonic sensor each temporally successive measurement cycles preferably differ in their respective excitation pattern.
• a jittering of the starting time to an excitation by one of the excitation pulses C9, Cl1, C3 or C4 may additionally take place.
• Ultrasonic sensors 1 to 12 are shown in tabular form in FIG.
• the rows of the table refer to time intervals that are available for a measuring cycle. In such a time interval, both the excitation of the electroacoustic transducer and the reception of reflected ultrasonic signals and the determination of an object information occur. These time intervals can each have the same length, but it can also be provided different lengths.
• the columns of the table respectively refer to a pair of ultrasonic sensors 1 and 7, 2 and 8, 3 and 9, 4 and 10, 5 and 11 respectively arranged at the front and rear.
• Time interval la according to its first measuring cycle with a
• Transducer of the ultrasonic sensors 1 and 7 is thus charged with a corresponding excitation pulse and each sends a corresponding measurement signal.
• the ultrasonic sensors 3 and 9 are driven with an excitation pulse of the form Cll.
• the ultrasonic sensors 5 and 11 are driven with an excitation pulse of the form C9.
• the ultrasonic sensor pair 2/8 is then triggered in a second time interval lb with an excitation pulse of the form C9.
• the ultrasonic sensor pair 4/10 is driven with an excitation pulse of the form Cll.
• the ultrasonic sensor pair 6/12 is driven with an excitation pulse of the form C3
• the ultrasonic sensor pair 3/9 is driven with an excitation pulse of the form C9.
• the ultrasonic sensor pair 5/11 is driven by an excitation pulse of the form Cll.
• Ultrasonic sensor pair 1/7 driven with an excitation pulse of the form C3.
• the ultrasound sensor pair 3/9 is driven by an excitation pulse of the form Cll.
• the ultrasonic sensor pair 5/11 is driven with an excitation pulse of the form C9.
• Ultrasonic sensor pair 2/8 driven with an excitation pulse of the form C9.
• the ultrasonic sensor pair 4/10 is driven with an excitation pulse of the form Cll. Also at the same time the ultrasonic sensor pair
• Form C9 activated.
• the ultrasonic sensor pair 5/11 is driven by an excitation pulse of the form Cll.
• time subsequent eighth time interval 4b is the
• each ultrasonic sensor or each ultrasonic sensor pair considered individually from shot to shot changes its excitation pattern.
• a measurement is carried out with the ultrasonic sensor 1 in the first time interval.
• the first time interval thus corresponds to the first measuring cycle of the ultrasonic sensor 1.
• the electroacoustic transducer of the ultrasonic sensor 1 is excited to mechanical oscillations with a frequency-modulated excitation pulse having the shape C3.
• the ultrasonic sensor 1 remains passive until the second measurement cycle of the ultrasonic sensor 1 is performed in the third time interval.
• Ultrasonic sensor 1 with a frequency-modulated excitation pulse of the form C4 has excited to mechanical vibrations.
• the third measuring cycle of the ultrasonic sensor 1 takes place in the fifth time interval.
• Measuring cycle of the ultrasonic sensor 1 takes place in the seventh time interval. In each measurement cycle, the frequency response of the
• Ultrasonic sensors 1 to 12 the respective ultrasonic sensor 1 to 12 receive a reflected ultrasonic signal 32.
• a reflected ultrasonic signal 32 By appropriate filtering of the received signals, which is adapted in particular in the form of a "matched filter" to the frequency response of the excitation pulse, actual echo signals can be distinguished from external signals 33 by the
• Frequency response of an excitation pulse in each measurement cycle from a group of predetermined frequency characteristics is selected randomly or in a predetermined order, it is ensured that even with identically designed distance measuring systems on foreign vehicles, there is only a very small chance that the foreign signal 33 exactly the same
• Frequency characteristic has, as the own measurement signal 30th

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• Engineering & Computer Science (AREA)
• Radar, Positioning & Navigation (AREA)
• Remote Sensing (AREA)
• Physics & Mathematics (AREA)
• Computer Networks & Wireless Communication (AREA)
• General Physics & Mathematics (AREA)
• Acoustics & Sound (AREA)
• Measurement Of Velocity Or Position Using Acoustic Or Ultrasonic Waves (AREA)

Applications Claiming Priority (2)

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• 2016
  • 2016-12-14 DE DE102016224932.0A patent/DE102016224932A1/de active Pending
• 2017
  • 2017-11-08 US US16/468,160 patent/US20200072973A1/en not_active Abandoned
  • 2017-11-08 JP JP2019528674A patent/JP6840241B2/ja active Active
  • 2017-11-08 EP EP17798180.0A patent/EP3555662A1/de not_active Withdrawn
  • 2017-11-08 WO PCT/EP2017/078553 patent/WO2018108388A1/de unknown
  • 2017-11-08 CN CN201780077526.1A patent/CN110073242B/zh active Active

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