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
  • G01S15/88—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
  • G01B—MEASURING LENGTH, THICKNESS OR SIMILAR LINEAR DIMENSIONS; MEASURING ANGLES; MEASURING AREAS; MEASURING IRREGULARITIES OF SURFACES OR CONTOURS
  • G01B17/00—Measuring arrangements characterised by the use of infrasonic, sonic or ultrasonic vibrations
  • G01B17/02—Measuring arrangements characterised by the use of infrasonic, sonic or ultrasonic vibrations for measuring thickness
• • 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
  • G01S15/42—Simultaneous measurement of distance and other co-ordinates
• • 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
  • G01S7/539—Details of systems according to groups G01S13/00, G01S15/00, G01S17/00 of systems according to group G01S15/00 using analysis of echo signal for target characterisation; Target signature; Target cross-section
• • 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
  • G01S15/46—Indirect determination of position data
• • 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
  • G01S15/86—Combinations of sonar systems with lidar systems; Combinations of sonar systems with systems not using wave reflection
• • 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
  • G01S15/46—Indirect determination of position data
  • G01S2015/465—Indirect determination of position data by Trilateration, i.e. two transducers determine separately the distance to a target, whereby with the knowledge of the baseline length, i.e. the distance between the transducers, the position data of the target is determined
• • 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
  • G01S2015/932—Sonar systems specially adapted for specific applications for anti-collision purposes of land vehicles for parking operations
• • 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
  • G01S2015/937—Sonar systems specially adapted for specific applications for anti-collision purposes of land vehicles sensor installation details
• • 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
  • G01S2015/937—Sonar systems specially adapted for specific applications for anti-collision purposes of land vehicles sensor installation details
  • G01S2015/938—Sonar systems specially adapted for specific applications for anti-collision purposes of land vehicles sensor installation details in the bumper area

Definitions

• the invention relates to a method for characterizing an object in the surroundings of a motor vehicle using an assistance system of the motor vehicle, in which the motor vehicle is moved relative to the object and ultrasonic signals are emitted using an ultrasonic sensor of the assistance system.
• echoes of the ultrasonic signals reflected by the object are received and respective amplitudes of the received echoes are determined by means of a control device, with a classification of a height of the object being determined based on the amplitudes.
• the invention also relates to an assistance system with an ultrasonic sensor and a control device, which is designed to carry out such a method.
• Ultrasonic sensors usually include a transmitter that emits ultrasonic signals that propagate in air at the speed of sound of about 340 meters per second.
• a membrane of the ultrasonic sensor is usually excited to mechanical vibrations with a corresponding transducer element.
• the ultrasonic signal is reflected as an echo by objects in the vicinity and is detected by a receiver device of the ultrasonic sensor.
• the distance, or to put it another way, the distance to the object can be determined on the basis of the transit time difference between the time of transmission and the time of reception, taking into account the propagation speed of the ultrasonic signal.
• the amplitude of the reflected ultrasonic signal or the echo can also be determined here.
• ultrasonic sensors for motor vehicles are used to detect the surroundings in a range of up to about 7 meters.
• Ultrasonic sensors are particularly important in semi-automatic or automatic driving maneuvers, especially in connection with parking applications, such as the Parking distance measurement, parking space search or when parking.
• the motor vehicle is usually moved relative to the objects, with a measurement cycle being carried out at predetermined times during the movement. With each measuring cycle, an ultrasonic signal is emitted with an ultrasonic sensor.
• Methods and corresponding assistance systems are already known from the prior art, which provide the driver with various information about the surroundings of the motor vehicle using ultrasonic sensors and support him in maneuvering the motor vehicle and in particular in locating a parking space and parking the motor vehicle in the parking space .
• assistance systems that are equipped with parking space localization and show the driver whether there is a parking space in the immediate vicinity of the motor vehicle or whether an existing parking space is large enough to park the motor vehicle in it.
• assistance systems require information about objects in the vicinity of the motor vehicle, which can be formed, for example, by parked vehicles, boards, walls and walls.
• the height of the object is usually also important.
• the height is an important factor in deciding whether an object or obstacle can be driven over or not.
• the motor vehicle is maneuvered at least semi-autonomously based on the measurements of an ultrasonic sensor, it is desirable to determine the height of the detected object.
• Determining height with one-dimensional (1D) ultrasonic sensors that are regularly used in motor vehicles, ie ultrasonic sensors for determining distance, is fundamentally very difficult due to physical limitations.
• Such an ultrasonic sensor cannot directly measure the height of an object.
• a camera is therefore additionally used to determine the height and the height is estimated based on a 2 DB image, or a method for estimating the height based on triangulation that is based on a number of sensors is used.
• methods based on a camera or multiple sensors do not utilize the advantages of a 1D ultrasonic sensor in terms of costs and robustness.
• a method and an assistance system of the type mentioned are known, for example, from DE 10 2004 047 479 A1.
• To classify the height of an object when a motor vehicle drives past the object located to the side of the motor vehicle ultrasonic signals are emitted by means of an ultrasonic sensor of the motor vehicle and the echoes of the ultrasonic signals reflected by the objects are received. Based on an amplitude of a received echo, classification of the height of the object is determined.
• the present invention is based on the object of specifying an alternative method for characterizing an object in the surroundings of a motor vehicle and a corresponding assistance system which enables the most cost-effective and reliable classification of the height of the object.
• the motor vehicle is moved relative to the object and ultrasonic signals are emitted using an ultrasonic sensor, in particular a 1D ultrasonic sensor, of the assistance system.
• ultrasonic sensor in particular a 1D ultrasonic sensor
• echoes of the ultrasonic signals reflected by the object are received, with the respective amplitudes of the received echoes being determined by means of a control device, and with a classification of a height of the object being determined on the basis of the amplitudes.
• a respective amplitude correction factor which takes into account an azimuth angle of the object in relation to the ultrasonic sensor, is determined for the received echoes and the respective amplitudes are corrected based on the corresponding amplitude correction factor, with the classification of the height of the object based on a determined first amplitude change by comparing a first corrected amplitude of a first echo is determined with a second corrected amplitude of a second echo received after the first echo.
• the invention is initially based on the consideration that a cost-effective classification of the height of an object is made possible if a sensor of the motor vehicle is used that is already installed, and that a particularly cost-effective and robust classification is further promoted by the fact that no computationally complex and error-prone fusion with sensor data from another sensor, or more precisely, another type of sensor, in particular a camera, is carried out.
• the invention is also based on the consideration that the radiation pattern of an ultrasonic sensor is basically a function of the elevation angle and the azimuth angle, i.e. that the power of an ultrasonic signal that is emitted by an ultrasonic sensor to an object in the detection area depends on the elevation angle and the azimuth angle of the object in relation to the ultrasonic sensor.
• the ultrasonic sensor changes, in particular below a certain distance between the object and the motor vehicle, to be more precise, and consequently the elevation angle and thus the power, or in other words the amplitude of the reflected ultrasonic signal as a function of the distance between the motor vehicle or ultrasonic sensor and the object.
• This fact in particular can be used to determine the classification of the height of an object.
• the invention provides that the classification of the height of the object is determined based on the sensor data of an ultrasonic sensor moving relative to the object, in particular a 1D ultrasonic sensor, wherein for the received echoes, a respective amplitude correction factor, which takes into account an azimuth angle of the object in relation to the ultrasonic sensor, is determined and the respective amplitudes are corrected based on the corresponding amplitude correction factor, and the classification of the height of the object is based on a determined first amplitude change by comparing a first corrected amplitude of a first echo is determined with a second corrected amplitude of a second echo received after the first echo.
• a respective amplitude correction factor which takes into account an azimuth angle of the object in relation to the ultrasonic sensor
• the configuration according to the invention has the advantage that it provides a method that enables cost-effective and reliable classification of the height of the object, in particular when the azimuth angle of the object relative to the ultrasonic sensor changes during the movement of the motor vehicle.
• the objects to be characterized can be objects that extend from a ground, for example a road surface or other terrain, and extend essentially orthogonally to the ground. However, they can also be objects that do not extend from the ground, such as a crossbar of a fence, or that do not extend orthogonally to the ground, such as a ramp.
• the ultrasonic sensor in particular a 1D ultrasonic sensor, can be arranged, for example, in or behind a bumper of the motor vehicle.
• the ultrasonic sensor in particular a 1D ultrasonic sensor, can be arranged in or behind a body component, for example a door of the motor vehicle.
• 1 D ultrasonic sensor can be used.
• a number of ultrasonic sensors in particular a number of 1D ultrasonic sensors, can also be used.
• the two classes "high” and “low” in particular are used to classify the height of the object.
• the object is classified as “high” if the object is at least at the installation height of the ultrasonic sensor, if the object has a height that corresponds at least to the installation height of the ultrasonic sensor.
• the object is classified as “low” if the object is below the installation height of the ultrasonic sensor, ie if the object has a height that is less than the installation height of the ultrasonic sensor.
• the azimuth angle indicates a position of the object with respect to the ultrasonic sensor in a horizontal direction.
• An amplitude is corrected in particular by scaling the value of the amplitude based on the corresponding amplitude correction factor, preferably by multiplying or dividing the value of the amplitude by the corresponding amplitude correction factor, with the result of the multiplication or division representing the corrected amplitude.
• the amplitude correction factor is dependent on a horizontal radiation pattern of the ultrasonic sensor.
• the amplitude correction factor of a received echo is thus determined based on the azimuth angle of the object in relation to the ultrasonic sensor and the horizontal radiation pattern of the ultrasonic sensor.
• the radiation pattern reflects the power of the ultrasonic signal, which is emitted by the ultrasonic sensor, as a function of the azimuth angle.
• the radiation pattern thus defines a specific power value of the ultrasonic signal for each azimuth angle.
• the power value of the corresponding ultrasonic signal assigned to this azimuth angle is read out then used directly as an amplitude correction factor or to determine the amplitude correction factor of the received echo.
• the azimuth angle is determined by trilateration using echoes that were received before the first echo and the second echo and/or based on signals from an area sensor of the motor vehicle that is different from the ultrasonic sensor.
• the environment sensor can be designed as a radar sensor, a lidar sensor and/or a camera.
• the first echo and the second echo are echoes that follow one another in terms of time, in particular echoes that follow one another immediately in terms of time.
• the object is in a close range of the motor vehicle, preferably at a distance of up to two meters from the ultrasonic sensor of the motor vehicle, wherein when the motor vehicle approaches the object, the object is classified as low if the first amplitude change is a Amplitude decrease is determined over time, and the object is classified as high if an amplitude increase over time is determined as the first amplitude change.
• the classification as low is determined in particular for an object which is located below the installation height of the ultrasonic sensor, ie which in particular has a height which is less than the installation height of the ultrasonic sensor.
• Such an object is a curb, for example.
• the classification as high is determined in particular for an object that is at least at the installation height of the ultrasonic sensor, that is to say that in particular has a height that corresponds at least to the installation height of the ultrasonic sensor.
• an object is, for example, a wall, a fence or a vehicle.
• the corrected amplitude of the reflected ultrasonic signal or echo depends only on the distance between the object and the ultrasonic sensor.
• the corrected amplitude of the reflected ultrasonic signal becomes larger when the motor vehicle, more precisely, when the ultrasonic sensor approaches such an object, ie when the distance between the object and the ultrasonic sensor becomes smaller.
• the elevation angle changes below a certain distance between the object and the ultrasonic sensor and continues to decrease while the motor vehicle or the ultrasonic sensor moves towards the object.
• the corrected amplitude of the reflected ultrasonic signal becomes smaller when the motor vehicle or the ultrasonic sensor approaches such an object. It is true that the corrected amplitude increases as the distance between the object and the ultrasonic sensor decreases.
• the dominant factor here is that the elevation angle becomes smaller as the distance decreases, as a result of which the corrected amplitude of the reflected ultrasonic signal decreases overall.
• the classification of the height of the object is determined based on a comparison of the first amplitude change with a second amplitude change, the second amplitude change being determined by comparing a third corrected amplitude of a third echo, which was received after the second echo, with the second corrected one amplitude of the second echo or with a fourth corrected amplitude of a fourth echo received after the second echo and before the third echo.
• two changes in amplitude are compared with one another, which further promotes the robustness of the classification of the height of the object.
• the object when the motor vehicle approaches the object, the object is classified as low if an amplitude increase over time is determined as the first amplitude change and an amplitude decrease over time is determined as the second amplitude change.
• an object such as a curb, which is below the installation height of the ultrasonic sensor, i.e. which in particular has a height that is lower than the installation height of the ultrasonic sensor, if this object is not yet in the immediate vicinity of the motor vehicle is located, preferably at a distance of more than two meters from the ultrasonic sensor of the motor vehicle, the elevation angle is at least approximately 90°.
• the corrected amplitude of the reflected ultrasonic signal depends essentially only on the distance between the object and the ultrasonic sensor.
• the corrected amplitude of the reflected ultrasonic signal or echo initially increases when the motor vehicle or the ultrasonic sensor approaches such an object, ie when the distance between the object and the ultrasonic sensor becomes smaller.
• the first change in amplitude results here in an amplitude increase over time.
• the elevation angle changes as it approaches further, whereby this becomes less than 90° and successively decreases as the distance is further approached or reduced.
• the corrected amplitude of the reflected ultrasonic signal also gradually decreases with further approximation. It is true that the corrected amplitude increases as the distance between the object and the ultrasonic sensor decreases.
• the dominant factor here is that the elevation angle becomes smaller as the distance decreases, as a result of which the corrected amplitude of the reflected ultrasonic signal decreases overall.
• the second change in amplitude results in an amplitude decrease over time. If, based on the comparison of the first amplitude change with the second amplitude change, an amplitude increase over time was determined as the first amplitude change and an amplitude decrease over time was determined as the second amplitude change, the object is classified as low.
• the object is in a close range of the motor vehicle, preferably at a distance of up to two meters from the ultrasonic sensor of the motor vehicle, with the object being classified as low when the motor vehicle approaches the object if the first amplitude change and an amplitude decrease over time is determined as the second amplitude change, and if the second amplitude change is also greater than the first amplitude change. A measure of the amplitude decrease is therefore taken into account here.
• the elevation angle decreases successively while the motor vehicle or the ultrasonic sensor moves further towards the object.
• the corrected amplitude of the reflected ultrasonic signal or echo also gradually decreases as it approaches. It is true that the corrected amplitude increases as the distance between the object and the ultrasonic sensor decreases.
• the dominant factor here is that the elevation angle becomes smaller as the distance decreases, as a result of which the corrected amplitude of the reflected ultrasonic signal decreases overall.
• the second change in amplitude thus results in an amplitude decrease over time which is greater than the decrease in amplitude of the first change in amplitude, as a result of which the object is classified as low.
• the object is in a close range of the motor vehicle, preferably at a distance of up to two meters from the ultrasonic sensor of the motor vehicle, with the object being classified as high when the motor vehicle approaches the object if the first amplitude change and an amplitude increase over time is determined as the second change in amplitude, and if the second amplitude change is greater than the first amplitude change.
• a measure of the amplitude increase is therefore taken into account here.
• the power, more precisely, the corrected amplitude of the reflected ultrasonic signal depends only on the distance between the object and the ultrasonic sensor.
• the corrected amplitude of the reflected ultrasonic signal or echo becomes larger when the motor vehicle or the ultrasonic sensor approaches such an object, ie when the distance between the object and the ultrasonic sensor becomes smaller.
• the second change in amplitude thus results in an increase in amplitude over time which is greater than the increase in amplitude of the first change in amplitude, as a result of which the object is classified as high.
• the comparison of the amplitude changes is based on a difference and/or a ratio of the amplitude changes.
• the comparison of the corrected amplitudes is based on a difference and/or a ratio of the corrected amplitudes.
• the classification of the height of the object is determined if the first amplitude change is also above a predefined threshold value in terms of absolute value. In this way, the reliability of the determination of the classification of the height of the object is further increased.
• the classification of the height of the object is preferably determined if, in addition or as an alternative, the amount of the second change in amplitude is above a predetermined threshold value.
• the threshold value is predetermined as a function of a current speed of the motor vehicle and/or a temperature in the area surrounding the motor vehicle and/or a humidity level in the area surrounding the motor vehicle and/or an installation height of the ultrasonic sensor on the motor vehicle. Since the temperature in and around the motor vehicle has a noticeable effect on the airborne sound insulation, the temperature can be recorded using an appropriate sensor and the threshold value can be adjusted accordingly. The same applies to the humidity. This leads to an even more reliable classification of the height of the object.
• the method is used in an assisted and/or semi-automatic and/or automatic parking method.
• the present invention includes an assistance system with an ultrasonic sensor and a control device.
• the control device is designed to carry out the method according to the invention.
• 1 is a radiation diagram showing a radiation pattern of an ultrasonic sensor as a function of the azimuth angle
• 2 is a radiation diagram showing a radiation pattern of an ultrasonic sensor as a function of elevation angle
• FIG. 3 is a diagram showing elevation angle as a function of distance of the ultrasonic sensor of FIG. 2 from an object
• FIG. 4 shows a flowchart of a method for characterizing an object in an area surrounding a motor vehicle.
• FIG. 1 represents a radiation pattern 1 of an ultrasonic sensor as a function of the azimuth angle. From this it can be seen that the radiation pattern 1 of the ultrasonic sensor is a function of the azimuth angle, i.e. that the power of an ultrasonic signal that is emitted by an ultrasonic sensor to an object in the detection area and thus also the power, or in other words the amplitude of the signal emitted by the object reflected ultrasonic signal or echoes, depends on the azimuth angle.
• the power, or in other words the amplitude of the ultrasonic signal or echoes reflected by the object is greater than when the object is in relation to the ultrasonic sensor located at an azimuth angle of 60°.
• FIG. 2 represents a radiation pattern 2 of an ultrasonic sensor as a function of the elevation angle. From this it can be seen that the radiation pattern 2 of the ultrasonic sensor is a function of the elevation angle, ie that the power of an ultrasonic signal which is emitted by an ultrasonic sensor to an object in the detection range depends on the elevation angle. If an object is at an elevation angle of 90°, ie at least at an installation height of the ultrasonic sensor in a motor vehicle, the elevation angle does not change when the motor vehicle, or more precisely, the ultrasonic sensor, approaches the object. The power, or to put it another way, the amplitude of the reflected ultrasonic signal or echo depends only on the distance between the ultrasonic sensor and the object. The amplitude of the reflected ultrasonic signal therefore becomes successively larger when the motor vehicle or the ultrasonic sensor approaches a high object.
• the elevation angle and thus the power or amplitude of the reflected ultrasonic signal change as a function of the distance between the motor vehicle or ultrasonic sensor and the object.
• the elevation angle becomes successively smaller until it reaches approximately 0° as soon as the ultrasonic sensor is located directly on the object.
• FIG. 3 shows a diagram representing the elevation angle as a function of the distance of the ultrasonic sensor according to FIG. 2 from an object.
• the object has a height that is 40 cm less than the installation height of the ultrasonic sensor in the motor vehicle.
• the object is designed here as a curb.
• the diagram shows that if the object is not yet in the close range of the motor vehicle, in particular at a distance of more than two meters from the ultrasonic sensor of the motor vehicle, the elevation angle is approximately 90°.
• the power, or more precisely, the amplitude of the reflected ultrasonic signal depends essentially only on the distance between the object and the ultrasonic sensor.
• the amplitude of the reflected ultrasonic signal increases when the motor vehicle or the ultrasonic sensor approaches such an object, ie when the distance between the object and the ultrasonic sensor becomes smaller.
• the elevation angle gradually decreases noticeably as it approaches further.
• the amplitude of the reflected ultrasonic signal also gradually decreases as it gets closer. It is true that the amplitude itself increases as the distance between the object and the ultrasonic sensor decreases.
• the dominant factor here is that the elevation angle becomes smaller as the distance decreases, as a result of which the amplitude of the reflected ultrasonic signal decreases overall.
• the relationship described with reference to FIGS. 2 and 3 basically assumes that the azimuth angle of the object in relation to the ultrasonic sensor does not change during the movement of the motor vehicle. However, since the situation often occurs in practice that the azimuth angle of the object in relation to the ultrasonic sensor changes during the movement of the motor vehicle, this change is taken into account according to the invention when characterizing the object by determining and using an amplitude correction factor that changes the azimuth angle of the Object considered in relation to the ultrasonic sensor. In this way, the relationship described with reference to FIGS. 2 and 3 can be used to determine the classification of the height of an object, even if the azimuth angle of the object changes in relation to the ultrasonic sensor while the motor vehicle is moving.
• FIG. 4 shows a flow chart of a method 100 for characterizing an object in an area surrounding a motor vehicle.
• the motor vehicle includes an assistance system with a control device and a 1D ultrasonic sensor, which is arranged on a front bumper of the motor vehicle and has a radiation pattern according to FIGS.
• the front of the motor vehicle approaches the object from a distance of around 2.5 meters and the ultrasonic sensor continuously emits ultrasonic signals.
• the object is a curb, which has a height that is about 40 cm less than the installation height of the ultrasonic sensor in the motor vehicle.
• a first echo is received and a first amplitude of the first echo is determined.
• a current azimuth angle of the object in relation to the ultrasonic sensor is determined by trilateration based on echoes received before the first echo, and an amplitude correction factor is calculated based on the azimuth angle determined here and the horizontal radiation pattern 1 of the ultrasonic sensor according to FIG determined for the first echo.
• the power value of the ultrasonic signal assigned to this azimuth angle is read out, which is then used to determine the amplitude correction factor.
• the first amplitude is then corrected by scaling the value of the first amplitude based on the amplitude correction factor, in particular by multiplying or dividing the value of the first amplitude by the amplitude correction factor, the result of the scaling, in particular the multiplication or division, being the corrected first amplitude.
• a second echo temporally following the first echo is received and a second amplitude of the second echo is determined.
• a current azimuth angle of the object in relation to the ultrasonic sensor is determined by trilateration based on echoes received before the second echo, and an amplitude correction factor is calculated based on the azimuth angle determined here and the horizontal radiation pattern 1 of the ultrasonic sensor according to FIG determined for the second echo. For this purpose, based on the radiation pattern 1 for the azimuth angle determined in the present case, the power value of the ultrasonic signal assigned to this azimuth angle is read out, which is then used to determine the amplitude correction factor.
• the second amplitude is then calculated by scaling the value of the second amplitude based on the amplitude correction factor, in particular by multiplication or a Division of the value of the second amplitude with the amplitude correction factor, corrected, the result of the scaling, in particular the multiplication or division, representing the corrected second amplitude.
• a first change in amplitude is determined based on a comparison of the first corrected amplitude with the second corrected amplitude.
• an amplitude increase is determined. Since the object is not yet in the vicinity of the motor vehicle at the time of the measurement, i.e. at a distance of more than two meters from the ultrasonic sensor of the motor vehicle, the elevation angle is approximately 90°. Consequently, the corrected amplitude of the reflected ultrasonic signal depends essentially only on the distance between the object and the ultrasonic sensor. The corrected amplitude of the reflected ultrasonic signal thus becomes larger when the motor vehicle or the ultrasonic sensor approaches such an object, ie when the distance between the object and the ultrasonic sensor becomes smaller.
• the first change in amplitude results here in an amplitude increase over time.
• step 102 Since the object was not yet in the vicinity of the motor vehicle at the time of the measurement, no final classification of the height of the object takes place based on the determined change in amplitude and the method 100 goes back to step 102. It is therefore further, temporally the second echo following third echo is received and a third corrected amplitude of the third echo is determined.
• a second change in amplitude is then determined in step 103 based on a comparison of the second corrected amplitude with the third corrected amplitude. Since the motor vehicle has meanwhile moved further in the direction of the object and at the time of the further measurement the object is now in the immediate vicinity of the motor vehicle and here specifically at a distance of 0.5 meters from the motor vehicle or ultrasonic sensor, the second amplitude change is a amplitude decrease determined. This is because the elevation angle in this area is now much less than 90°, which is why results in the corrected amplitude of the reflected ultrasonic signal having decreased overall, as a result of which the third corrected amplitude of the third echo is smaller than the second corrected amplitude of the second echo. The second change in amplitude thus results in an amplitude decrease over time.
• a classification of the height of the object is determined.
• the first change in amplitude is compared with the second change in amplitude. Since in the present case an amplitude increase over time is determined as the first amplitude change and an amplitude decrease over time is determined as the second amplitude change, the object is classified as low.
• the height of the object in the present case the curb, can be classified in a cost-effective and reliable manner, especially when the azimuth angle of the object relative to the ultrasonic sensor changes during the movement of the motor vehicle.

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

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• 2021
  • 2021-09-13 DE DE102021210082.1A patent/DE102021210082B3/de active Active
• 2022
  • 2022-08-22 CN CN202280061073.4A patent/CN117916628A/zh active Pending
  • 2022-08-22 EP EP22761403.9A patent/EP4402513A1/de active Pending
  • 2022-08-22 US US18/691,646 patent/US20240402336A1/en active Pending
  • 2022-08-22 WO PCT/DE2022/200194 patent/WO2023036377A1/de not_active Ceased
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