FR3001040B1 - ENVIRONMENTAL FIELD SENSOR SYSTEM - Google Patents

Abstract

A system (1) of surrounding field sensors comprising a transmitter (Sx1, Sx2), a first receiver array (Sx) having a first receiver (Sx1), and a second receiver (Sx2), and an operation unit (3 ). The transmitter (Sx1, Sx2) generates signals to produce an acoustic echo by the objects (R) of the surrounding field, and an operating unit (3) exploits the phase difference between the signals received by the first receiver ( Sx1) and the second receiver (Sx2), and - determines a directional information of a parasitic sound source (Q) generating a stray sound in the reception signal for the first receiver network (Sx). Exploit separately the component of sounds contained in the reception signal corresponding to the first directional information, and the echo generated by the transmitters (Sx1, Sx2) to operate separately including neutralize it.

Description

Field of the invention

The present invention relates to a surrounding field sensor system including a system of surrounding ultrasound-based field sensors.

State of the art

The surrounding field sensor systems are used in particular in the automobile industry. Most of these systems exploit the echo received by receivers in the system. To generate echo from surrounding field objects, the system radiates appropriate signals into the surrounding field. From the travel time of the received echoes we can determine the distance between the object of the surrounding field and the receivers. But one can have sources of its parasite in the environment of the system which hinder or complicate the detection of the echo. In particular, impulse noise and ultrasonic sources are difficult to eliminate by an ultrasound-based system.

In the automotive field, ultrasonic sensor systems composed of two to six separate sensors installed at the front and / or rear of the vehicle are also known. The distance of the obstacles is determined from the time of travel of the signals in the horizontal direction in which the object of the environment is located, proceeding by triangulation. But if in the environment there are sources of its parasite, all receivers of the system detect signals that do not correlate with the transmitted pulse. Characteristically, obstacles are then detected at many distances or even at all distances. For example, municipal sweepers, construction machinery, tire rolling noise, very steep steps, a bunch of noisy keys or other ultrasound systems from other vehicles (eg in a car park) may disrupt the exploitation of the echoes received. In this case, it is no longer possible to distinguish the disturbances characteristic of actual obstacles.

Furthermore, according to the state of the art, sound-based network systems are known that use the phase difference between several receivers to determine the angle with respect to a sound source. Such a system is described in the documents FR-2817973-A1 and DE 2010 062 990 A1. These systems, install two independent receivers very close to one another and from the phase difference of the incident wavefront between the two receivers, we conclude at a direction of incidence. But in such systems, the sources of its parasite can disrupt echo recognition (ie the exploitation of the phase difference so that the system is "blinded".

Purpose of the invention

The object of the present invention is to overcome the drawbacks of the state of the art and to develop a system of surrounding field sensors whose signal exploitation is more resistant to the sources of its parasite.

DESCRIPTION AND ADVANTAGES OF THE INVENTION To this end, the subject of the invention is a system of surrounding field sensors comprising: - a transmitter, - a first receiver network having a first receiver, and a second receiver, and - a unit of operation, the transmitter generating signals to produce an acoustic echo by the surrounding field objects, and an operating unit, - exploiting the phase difference between the signal received by the first receiver and that received by the second receiver determining a directional information of a source of parasitic sound generating a parasitic sound in the reception signal of the first receiver network, and separately exploiting the component of its content in the reception signal corresponding to the first directional information, the echo generated by the transmitters to exploit it separately, in particular to neutralize it.

Thus, the system according to the invention of surrounding field sensors comprises a first receiver network with a first receiver and a second receiver. A receiver in the context of the present invention is thus an "element making it possible to transform an incident signal independently of other receivers" so that between two receivers installed in the vicinity of one another, for example, it will be possible to determine a difference phase for one and only same incident wavefront. The receiver network may comprise several receivers, in particular installed in different directions.

In particular, the receiver array may include ultrasonic converters as the first and second receivers. In addition the system may include a transmitter. This is in the form of its own component or by the emission function also performed by the receivers of a receiver network. The transmitter allows the system to transmit a transmission signal whose echo (s) according to the invention, as described below, will be recognized and separated from the incident parasitic sound.

The system according to the invention also comprises an operating unit which exploits the phase (phase difference) between the reception signal of a first receiver and that of a second receiver. The operating unit comprises for example a microcontroller, a microprocessor or other signal exploitation means which can furthermore provide other functions internal to the system or external to the system. The operating unit determines a first directional information of the source generating the spurious sound contained in the reception signal for the first receiver network. In the case of a one-dimensional receiver array with at least two receivers adjacent to each other in the horizontal direction, the first directional information thus characterizes a horizontal direction (azimuth or horizontal angle) of a incident wave front of the parasitic sound. The signal of its parasite can also be recognized and characterized by different properties.

For example, in the context of a measurement cycle (that is to say for example the time between a first and a second transmission of a measurement signal towards the environment) to wait only once echo in one direction because the other objects seen by the receiver (or the receiver network) behind the object of the environment that produces the reflection, are obscured (regardless of the deviation effect) and not do not send an echo. Thus, as soon as, in a predetermined period of time, predefined by the duration of the measuring cycle, several echoes or a continuous sound are associated with one and the same direction, it may be concluded that a source of parasitic sound is present in this direction.

In addition the operating unit eliminates the signal received, the component of sound (parasitic sound) contained in the first directional information. In other words, the additional signals (signals used such as for example the echoes) contained in the reception signal can also be solved in the direction and their operation will be possible so that exclusively the components of its corresponding to the first information Directional will not be exploited (eg by a determination of travel time or distance).

The directional resolution is obtained according to the invention with the phase difference of the wave fronts arriving in the receiver network. This solution has the advantage that in spite of parasite sources, considerable in the environment of the system, it will be blinded only for the corresponding directional information or sound component of the source of its parasite while the components of its corresponding other directional information will be exploited as known in the state of the art in that these signals will be examined from the point of view of their relative offset (for example the pulse fronts of indes).

In particular, transmitters associated with the system of the invention may be used to radiate a signal in the system environment. By exploiting the echoes received from the environment, one can first grasp the difference between the signal emission and the components of its reflected (useful components) and from there, determine the path traveled. On the other hand, a correlation can also be made between the transmitted signal and the reflected signal received to determine the relationship of the two signals.

Preferably, the first receiver and the second receiver of the receiver network according to the invention are spaced apart by a distance less than the quotient of the speed of sound predictable according to the operating conditions and twice the working frequency of the first receiver and of the second receiver. The "distance" in the context of the present invention for the receiver is the "acoustic" distance, that is to say the distance of two corresponding sections of the receivers (middle of the membrane). In known manner, the speed of sound depends on different characteristics of the medium in which it unfolds and as an example we have an outside air temperature of 50 ° C. The working frequency of the usual systems for detecting the surrounding field by ultrasound is in a range between about 35 kHz and 65 kHz and preferably between 45 kHz and 55 kHz and particularly preferably the frequency is 48 kHz . The device according to the invention provides an appropriate location or direction resolution for incident ultrasound signals from the system environment.

Preferably, the first receiver array comprises a third receiver that underpins with the first receiver and the second receiver, a plane normal to the surrounding field to be captured. In other words, the first and second receivers may be spaced apart in the horizontal direction while the third receiver will be spaced in the vertical direction relative to the first receiver and / or the second receiver. In addition, the operating unit exploits the phase difference between the reception signal of the third receiver and the first receiver. This provides directional information regarding the vertical direction (ie height) of the surrounding field sound sources and echoes for operation. Alternatively or additionally, the operating unit uses the phase information of the signal received by the third receiver and the second receiver. Thus, the system and its operating unit make it possible to determine a second directional information for a source of parasitic sound generating the parasitic sound contained in the reception signal for the first receiver network. In other words, a parasitic source of sound will be associated with the arrangement defined above, not only in the horizontal direction but also in the direction of incidence in a vertical plane and will be taken into account for the operation of the components. of the incident sound. For example, these sound components can be eliminated in order to exploit other directional information (for example in spherical coordinates) for the sources of sound. This reduces the range of the receiver network in which the receiver network is temporarily blinded by the noise sources.

Preferably, the system according to the invention further comprises; a second receiver network with a fourth receiver, and a fifth receiver, the fourth receiver and the fifth receiver being associated and installed according to the first receiver and the second receiver, and with first directional information; determined by the first receiver network and in particular also a second directional information and with the aid of a third directional information determined by the second receiver network, the operating unit determines a residence range of one source of its parasite generating the parasitic sound contained in the reception signal for the second receiver network, and exploits and in particular removes separately the sound components of the useful signals of the residence range, components contained in the reception signal.

According to another characteristic of the invention, the reception ranges of the first network and the second network overlap in particular over more than 50% of their volumes.

According to another characteristic of the invention, using the form of a transmitted signal or with the aid of a predefined maximum number of signals contained in a data direction during a measuring cycle, the unit of operation classifies a received signal as a spurious signal.

According to another characteristic of the invention, the system provides a distance measurement and comprises in particular means for transmitting a signaling distinguishing the passage below a predefined critical distance. The operating unit can identify a direction by means of a first directional information obtained with the first receiver network and also a second directional information, the direction thus identified corresponding to the direction of the spurious sound for the first network of receivers.

If using the second network of receivers we determine the direction of this same source of its parasite, the operating unit can locate the source of its parasite exactly at the point of intersection of the two directions. In other words, the second network not only makes it possible to identify a parasitic source of sound for its horizontal direction and its vertical direction but gives the exact position for which it is necessary to neutralize the sound components contained in the reception signal. To apply the method developed above, it is necessary that the two receiver networks are advantageously spaced a certain distance because it will be in this way an obtuse angle at the point of intersection of the two directions. A system such as that defined above is able to locate the position of a parasite source of sound and to be able to safely recognize all the objects of the surrounding field at a certain distance from the source of its parasite because at least for the one of the two networks, the source of its parasite corresponds to another direction than that of the echo of the real objects of the surrounding field which are cut or drowned. In this way, a significantly lower range of the surrounding field will be disturbed by the source of its parasite which influences the recognition of objects of the surrounding field in the input range of at least two networks. The operating unit also exploits and locates the position for the signals next to the source of its parasite. The system according to the invention allows a particularly good and safe directional resolution.

Interestingly, the reception ranges of the first receiver array and those of the second receiver array are largely overlapping which, as indicated above, allows the source of its parasite to be identified in different directions and to obtain from this result the exact position as has been described.

According to another advantageous characteristic, the receivers and in particular the operating unit are intended to be integrated in a vehicle. A first receiver network and a second receiver network may be installed in the front bumper of a vehicle and connected to a common operating unit. It is advantageous that the receivers of the first receiver network and those of the second receiver communicate with the operating unit by separate channels. These channels may consist of separate lines. In principle it is also possible to consider coding the information in the receivers or in the receiver network which saves lines and collect the information by a common channel to transmit them to the operating unit.

According to another advantageous characteristic, the distance measuring system comprises means for transmitting a signaling. These means are for example constituted by a sound signal generator and / or an optical mission and / or a haptic emission. It is particularly advantageous to report the distance from the objects of the environment and exploit it with respect to predefined thresholds which presume a risk of collision for the vehicle. This makes it possible to recognize a predictable collision and to avoid it.

Preferably, the system according to the invention comprises one or more transmission units for transmitting signals towards the surrounding field. Receiver networks can even be designed to transmit signals to the surrounding field which is possible in a particularly simple way to transmit the signals and relate them to the echo thus avoiding additional circuits.

Particularly preferably, the receptors are ultrasound receptors, in particular ultrasound transceivers. Thus, the receiver networks according to the invention are made in the form of ultrasound emitter networks and in particular ultrasonic transceiver networks.

According to another characteristic, the subject of the invention is a vehicle equipped with a system as described above. The operating unit can itself, for example, provide other vehicle-specific functions so that the computing power will be used in common with these other functions.

drawings

The present invention will be described hereinafter with the aid of exemplary embodiments of an environmental field sensor system shown in the accompanying drawings in which: FIG. 1 is a schematic diagram of the ultrasonic detection an angle of incidence, - Figure 2 is a schematic diagram of the blindness of a known ultrasound system according to the state of the art, - Figure 3 shows a diagram of a first example of embodiment of a system according to the invention, - Figure 4 shows a flow chart explaining the operating steps of the embodiment of the invention, - Figure 5 is a diagram of a second embodiment of a system according to the invention, - Figure 6 is a schematic representation of an embodiment applied to a vehicle with two systems according to the invention.

Description of Embodiments of the Invention

FIG. 1 shows a system 1 of surrounding field sensors, comprising a first network of receivers Sx composed of a first receiver Sxi and a second receiver SX2. A wavefront (s) W of the system environment arrives at an angle alpha on the receivers Sxi and SX2 of the receiver array Sx. If it is assumed that the wavefront (s) W is plane, then there will be a difference of travel 6 between the first receiver Sxi and the second receiver SX2 for the components of the incident signal. Since the speed of sound is known or can be obtained from determined quantities (for example by using a temperature sensor), it will be possible, from the distance between the receivers Sxi, 2, in connection with the phase difference of the signals, conclude with the value of the angle a and thus obtain a first directional information relating to the source of its parasite. Insofar as the signal / echo has for example been recognized as its parasite by the technique described above.

Figure 2 shows a surrounding field sensor system 10 according to the state of the art. The bumper 20 houses a first receiver Sxi and a second receiver Syi at a relatively large distance from each other. A source of its parasite Q produces a permanent disturbance of the receivers Sxi and Syi so that the objects of the environment in the ranges x and y remain unknown or undetectable, the receivers Sxi and Syi being "blinded".

FIG. 3 shows a system 1 designed and installed according to the invention comprising a first network of receivers Sx and a second network of receivers Sy housed in a bumper 20.

A source of parasitic noise Q is in the reception range Ex, x + i and the first receiver network Sx and in the reception range Ey, y + i of the second receiver network Sy and thus disturb the two receiver networks. Sx> y. Among two recognizable R objects, a first is in the reception range Ey> y + i while a second object R is both in the reception range Ex> x + i and in the reception range Ey> y + i. This range is completely disturbed by the source of its parasite Q. However, the first network of receivers Sx determines a first directional information of the source of its parasite Q and the second network of receivers Sy identifies a second directional information of the source of its sound. However, this allows the object located in the two reception ranges EXjX + i, Ey, y + i to be recognized. An object U located outside the second receiving range Ey, y + i but within the first receiving range EX; X + i remains unknown because there is no second directional information from a second angle of observation (other angle of observation) of the system according to the invention.

Figure 4 is a flow chart explaining the steps of the method executed by the system 1 according to the invention. The system starts in the "Start" position, for example by connecting the ignition system of the vehicle, passing the reverse gear, operating a corresponding actuating device or other. In step 100, the surrounding field is detected using the first receiver network Sx and the second receiver network S i, that is to say that signals are received. In step 200 it is determined whether a corresponding transmission signal has been transmitted. In other words, the reception signal is analyzed to determine whether it is a transmission signal of the system reflected by an object R from the environment. In step 300, a decision is made: if it is an echo (Y), step 400 is used to exploit the echo travel time. If necessary, a warning signal is emitted if a minimum predetermined distance is exceeded by the user. Then, step 100 is continued as described above. Since in step 300 it has been found that the reception signal was a spurious signal N, the reception signal is processed in a second manner in step 500. This signal component will for example be eliminated from the signal reception or not taken into account in the farm. Then, the process continues by exploiting step 100. At each moment between the steps, it is checked whether a predefined breaking condition is fulfilled. If yes, the process ends.

FIG. 5 shows a system 1 according to the invention comprising an operating unit 3 and a signaling installation in the form of a loudspeaker 4 linked to the operating unit 3. A network of Sx receivers with two dimensions is connected to the operating unit 3. This network consists of Sxn-SX33 receivers. Using this two-dimensional network, it is possible to determine the exact direction of a source of sound emitting stray sound. If two networks of receivers separated by a minimum distance are used, it will be possible, with the aid of the directional information obtained, to determine exactly the position of a point corresponding to the source of its parasite. Vis-à-vis the device shown in Figure 3, and which can determine a "line" perpendicular to the plane of the drawing as a possible place of the source of its parasite Q, a network of dual receivers can provide a unity d also exploit the last remaining coordinates of the source of its parasite and eliminate the parasitic sound emitted by this source for exploitation.

FIG. 6 shows a passenger vehicle 5 both front and rear including a bumper 20 equipped with a system 1 such as that of FIG. 5. The systems can also comprise several Sx receiver networks. related to the reporting unit 3.

This system offers the same advantages as those described for the above system. The basic idea of the invention is not to exploit only the information of a single echo arriving in a surrounding field sensor system but to avoid the passing blindness (in the acoustic sense) of certain receivers by the presence sources of its parasite so as to also have a directional resolution of the sources of its parasite and that according to the constellation used we obtain several directional information or even a precise position of the source of its parasite. With the signals received concerning the position of the source of its parasite, it will be possible to take account of this information later in the operation to process it in a predefined manner, for example to eliminate it or not to take it into account.

Claims (10)

CLAIMS 1 °) System (1) of surrounding field sensors comprising: - a transmitter (Sxi, SX2), - a first receiver network (Sx) having a first receiver (Sxi), and a second receiver (SX2), and an operating unit (3), the transmitter (Sxi, SX2) generating signals for producing an acoustic echo by the objects (R) of the surrounding field, and an operating unit (3), - exploiting the difference of phase between the signal received by the first receiver (Sxi) and that received by the second receiver (Sx2), - determining a direction information of a parasitic sound source (Q) generating a parasitic sound in the reception signal of the first receiver network (Sx), and - separately exploiting the component of its content in the reception signal corresponding to the first directional information, the echo generated by the transmitters (Sxi, SX2) to operate separately, including the neutralize. 2) System according to claim 1, characterized in that the first receiver (Sxi) and the second receiver (Sx2) are spaced from each other by a distance less than the quotient of the speed of sound predictable in the conditions of use, in particular at an external air temperature of 50 ° C, by twice the working frequency of the first receiver (Sxi) and the second receiver (Sx2) in particular in a range of between 35 kHz-65 kHz and preferably in a range between 45 kHz-55 kHz. System according to Claim 1, characterized in that the first receiver network (Sx) further comprises: a third receiver (S 12) which underlies a plane with the first receiver (Sxi) and the second receiver (Sx) ( SX2) and operating unity (3), * uses the phase difference between the reception signal received by the third receiver (S12) and the first receiver (SX2) and / or between that of the third receiver (S12) and the receiver (S12). second receiver (Sx2), * determines a second directional information for the parasitic sound generated by the source of its parasite (Q) in the reception signal of the first receiver network (Sx), and * exploits, in particular suppresses, the components of its useful signals contained in the first and second directional information. 4) System according to claim 1, characterized in that it further comprises: - a second receiver network (Sy) with a fourth receiver (Syi), and a fifth receiver (Sy2), - the fourth receiver (Syi) ) and the fifth receiver (Sy2) being associated and installed according to the first receiver (Sxi) and the second receiver (SX2i), and - using a first directional information determined by the first receiver network (Sx) and in particular also a second directional information and with the aid of a third directional information determined by the second receiver network (Sy), the operating unit determines a residence range of a source of its parasite generating the parasitic sound contained in the reception signal for the second receiver network (Sy), and exploits, and in particular suppresses, the sound components of the useful signals of the residence range, components c held in the reception signal. 5 °) System according to claim 4, characterized in that the operating unit further exploits the signals next to the source of its parasite in particular depending on the position. 6 °) System according to one of claims 4 or 5, characterized in that the reception ranges of the first network (Sx) and the second network (Sy) overlap including more than 50% of their volumes. 7 °) System according to claim 1, characterized in that by means of the form of a transmitted signal or with the aid of a predefined maximum number of signals contained in a data direction during a measurement cycle, the operating unit classifies a received signal as a spurious signal. 8 °) System according to claim 1, characterized in that the system (1) provides a distance measurement and comprises in particular means (4) for transmitting a signal distinguishing the passage below a predefined critical distance. 9 °) System according to claim 1, characterized in that the receivers (Sxi, SX2, Syi, Sy2, Si 1-33) are ultrasonic receivers including ultrasonic transceivers. A vehicle comprising a system (1) according to any of claims 1 to 9, comprising: - a transmitter (Sxi, SX2), - a first receiver network (Sx) having a first receiver (Sxi), and a second receiver (SX2), and - an operating unit (3), the transmitter (Sxi, SX2) generating signals to produce an acoustic echo by the objects (R) of the surrounding field, and an operating unit (3), to exploit the phase difference between the signal received by the first receiver (Sxi) and that received by the second receiver (Sx2), - determining a direction information of a source of parasitic sound (Q) generating a its parasite in the reception signal of the first receiver network (Sx), and - separately exploit the component of its content in the reception signal corresponding to the first directional information, the echo generated by the transmitters (Sxi, SX2) to exploit it separately, especially the neut raliser.