METHOD FOR MEASURING EFFLUENT LEVELS IN A SEWERAGE NETWORK USING A CONNECTED ULTRASONIC SENSOR

Abstract

The invention relates to a method for measuring effluent levels in a wastewater network using a connected ultrasonic sensor, comprising a step of performing a plurality of measurements by transmitting and receiving ultrasound waves. Each measurement is induced by a triplet of parameters (time window, pulse train energy level, and detection ramp profile) allowing exploration of a target echo detection space. Each measurement is configured with a time window, a pulse train energy level, and a detection ramp profile. A criterion for selecting the measurement is based on the maximum distance that maximizes the signal-to-noise ratio. The invention also relates to a system for measuring effluent levels in a wastewater network, said system comprising a connected ultrasonic sensor. (Shorthand figure: Figure 3.)

Description

Title of the invention: METHOD FOR MEASURING EFFLUENT LEVELS IN A SANITATION NETWORK BY MEANS OF A CONNECTED ULTRASONIC SENSOR Technical field

[0001] The present invention relates to the field of measurement methods in sanitation networks.

[0002] The present invention relates more particularly to a method for measuring effluent levels in a sanitation network at the level of a manhole, by means of a connected ultrasonic sensor.

[0003] [Fig.l] is an overview of a measuring system in a sewerage network. [Fig.l] shows the manhole cover, the sensor and its pendulum attachment, ladder rungs and a bench.

[0004] In this context, the objective is to measure the distance between the sensor and the surface of the effluent. The echo returned by the rungs of the ladder or the bench can interfere with the quality of the measurement. Prior art

[0005] We seek to improve the directivity of the ultrasound beam to reduce the impact of interfering objects such as the rung of the ladder or the bench.

[0006] In the state of the art, sensors with extended cones are used for a limited improvement in directivity, but in this case, the size of the sensor is also increased.

[0007] Another technique consists of using local temporal filtering after analysis of the echo waveform. This temporal filtering is not sufficient when the measurement range of the observed object includes the obstacle to be excluded.

[0008] [Fig.2A] represents the state of the art. In [Fig.2A], we observe the fact that the bar obstacle is outside the measurement range and can therefore be excluded by temporal filtering.

[0009] [Fig.2B] also represents the state of the art

[0010] It can be seen in Figures 2A and 2B that the bench obstacle is located within the effluent level measurement range. Statement of the invention

[0011] The issues that arise are as follows: - The sensor technology must be low cost to be able to densify the measurement points. - The sensor measurement must be sufficiently precise to allow a measurement low dynamic (a few millimeters). - The directivity of the sensor must be sufficient to measure the bottom of the ditch and avoid obstacles in the pit (ladder rung, and especially the bench)

[0012] The invention aims to remedy the drawbacks of the prior art by responding to the challenges mentioned above.

[0013] For this purpose, the invention relates to a method for measuring effluent levels in a sanitation network by means of a connected ultrasonic sensor, comprising a step of carrying out a plurality of measurements by transmission and reception of ultrasound, each measurement being induced by a triplet of parameters (time window, energy level of the pulse train, and detection ramp profile) making it possible to explore a target echo detection space, each measurement being configured with a time window, an energy level of the pulse train, and a detection ramp profile; in which a decision criterion for the chosen measurement is based on the maximum distance which maximizes the signal-to-noise ratio.

[0014] According to one embodiment, a temporal filtering on the series of chosen measurements of type MAX_DUREE, which, on a sliding window of size DUREE, selects the maximum distance measurement among the measurements of this time window.

[0015] According to one embodiment, the measurement processing is partitioned between the local sensor and a remote platform.

[0016] According to one embodiment, said method comprises a step of adjusting the energy of the transmitted wave train so that the echo of the target occupies the maximum dynamic range at the input of the detector.

[0017] According to one embodiment, the growth parameters of the detection ramp are configurable.

[0018] The present invention also relates to a system for measuring effluent levels in a sanitation network, said system comprising a connected ultrasonic sensor, and further comprising means for carrying out a plurality of measurements by transmitting and receiving ultrasound, each measurement being induced by a triplet of parameters (time window, energy level of the pulse train, and detection ramp profile) making it possible to explore a target echo detection space, each measurement being configured with a time window, an energy level of the pulse train, and a detection ramp profile; in which a decision criterion for the chosen measurement is based on the maximum distance which maximizes the signal-to-noise ratio. Brief description of the drawings

[0019] [Fig.l] [Fig.l] is an overview of a measuring system in a sewerage network.

[0020] [Fig.2A] [Fig.2A] represents the state of the art.

[0021] [Fig.2B] [Fig.2B] also represents the state of the art.

[0022] [Fig.3] [Fig.3] illustrates temporal filtering.

[0023] [Fig.4A] [Fig.4A] illustrates spatial filtering by maximizing the signal-to-noise ratio.

[0024] [Fig.4B] [Fig.4B] also represents spatial filtering by maximizing the signal-to-noise ratio.

[0025] [Fig.5] [Fig.5] illustrates the MAX_DUREE filtering device.

[0026] [Fig.6] [Fig.6] represents the partitioning of the treatments. Detailed description

[0027] The present invention relates to a method for measuring effluent levels in a sanitation network by means of a connected ultrasonic sensor.

[0028] The method according to the invention comprises a step of carrying out a plurality of measurements by transmission and reception of ultrasound, each measurement being induced by a triplet of parameters (time window, energy level of the pulse train, and detection ramp profile) making it possible to explore a target echo detection space, each measurement being configured with a time window, an energy level of the pulse train, and a detection ramp profile. A decision criterion for the chosen measurement is based on the maximum distance which maximizes the signal-to-noise ratio.

[0029] In one embodiment, a temporal filtering on the series of chosen measurements of type MAX_DUREE, which, on a sliding window of size DUREE, selects the maximum distance measurement among the measurements of this time window.

[0030] In one embodiment, the measurement processing is partitioned between the local sensor and a remote platform.

[0031] In one embodiment, said method comprises a step of adjusting the energy of the transmitted wave train so that the echo of the target occupies the maximum dynamic range at the input of the detector.

[0032] In one embodiment, the growth parameters of the detection ramp are configurable.

[0033] [Fig. 3] illustrates the temporal filtering. In [Fig. 3] we observe the echo of the obstacle, the target to be detected as well as the temporal search window.

[0034] The method according to the present invention implements remotely controllable temporal filtering.

[0035] [Fig.4A] illustrates spatial filtering by maximizing the signal-to-noise ratio, with eight pulses.

[0036] [Fig.4B] also represents the spatial filtering by maximizing the ratio signal to noise, with four pulses.

[0037] It can be seen in Figures 4A and 4B that the amplitude of the interference from the bench is significantly reduced with the four-pulse setting.

[0038] Maximizing the signal-to-noise ratio by adapting the transmitted power is achieved as follows: - The objective is to adjust the energy of the transmitted wave train so that the target echo occupies the maximum dynamic range at the detector input. - When the target echo saturates the detector input, the energy perceived by the detector is reduced while the energy of the parasitic echo is conserved, inducing a reduction in the signal-to-noise ratio. - Conversely, if the amplitude of the target echo is low compared to the dynamic range of the detector input, the target echo risks falling below the threshold of the detection ramp.

[0039] Maximizing the signal-to-noise ratio by adapting the detection ramp profile is achieved as follows: - In the state of the art it is common to adjust the echo detection level over time using an RC type ramp. This makes it possible to take into account the decrease in power of the target echo as a function of its relative temporal distance from the pulse train emission peak. - The present invention implements such a ramp, but the growth parameters of this ramp are themselves configurable. - This setting allows you to adjust the ramp profile to the power of the received echo.

[0040] Maximizing the signal-to-noise ratio by combining the optimal parameters is achieved as follows (Size and position of the temporal filtering window of the echoes, energy level of the emitted ultrasonic pulse train and profile of the detection ramp.): - Step 1: Configuration of a measurement set. Each measurement is configured with a time window, a pulse train energy level, and a detection ramp profile. The measurement set therefore corresponds to a diversity of this triplet of configurations. - Step 2: The sensor device takes the measurements and transmits them to the decision-making device which is located either locally or on a remote platform. - Step 3: The decision-making device chooses from the measurement set the one with the greatest distance measurement. It is considered that this decision criterion allows, in the context of measuring the level of sanitation networks, to maximize the signal-to-noise ratio. - Step 4: Optionally, the time filtering device performs filtering MAX_DUREE on the time series of measurements from step 3.

[0041] [Fig.5] illustrates the MAX_DUREE filtering device.

[0042] A sliding MAX filter is applied to the time series of distance measurements from the decision device.

[0043] [Fig.6] represents the partitioning of the treatments.

[0044] In one embodiment, the measurement processing is partitioned between the local sensor and a remote platform.

[0045] The sensor performs a set of measurements with different parameters decided by the platform for each.

[0046] The platform defines the sensor measurement set and chooses the measurement that maximizes the signal-to-noise ratio according to the maximum distance criterion.

[0047] In addition, the platform performs MAX time filtering on the sequence of chosen measurements.

[0048] The present invention also relates to a system for measuring effluent levels in a sanitation network. The system comprises a connected ultrasonic sensor. It also comprises means for carrying out a plurality of measurements by transmitting and receiving ultrasound, each measurement being induced by a triplet of parameters (time window, energy level of the pulse train, and detection ramp profile) making it possible to explore a target echo detection space, each measurement being configured with a time window, an energy level of the pulse train, and a detection ramp profile. A decision criterion for the chosen measurement is based on the maximum distance which maximizes the signal-to-noise ratio.

Claims

Demands

1. A method for measuring effluent levels in a sewage system using a connected ultrasonic sensor, characterized in that it comprises a step of performing a plurality of measurements by transmitting and receiving ultrasound, each measurement being induced by a triplet of parameters (time window, pulse train energy level, and detection ramp profile) allowing exploration of a target echo detection space, each measurement being configured with a time window, a pulse train energy level, and a detection ramp profile; and in that a decision criterion for the chosen measurement is based on the maximum distance that maximizes the signal-to-noise ratio.

2. Method according to claim 1, characterized in that a time filtering on the series of selected measurements of type MAX_DUREE, which, on a sliding window of size DUREE, selects the maximum distance measurement among the measurements of this time window.

3. Method according to claim 1 or 2, characterized in that the measurement processing is partitioned between the local sensor and a remote platform.

4. A method according to claim 1, 2 or 3, characterized in that it comprises a step of adjusting the energy of the transmitted wave train so that the echo of the target occupies the maximum dynamic range at the inlet of the detector.

5. A method according to any one of the preceding claims, characterized in that the growth parameters of the detection ramp are configurable.

6. A system for measuring effluent levels in a sewage network, said system comprising a connected ultrasonic sensor, characterized in that it further comprises means for performing a plurality of measurements by transmitting and receiving ultrasound, each measurement being induced by a triplet of parameters (time window, pulse train energy level, and detection ramp profile) allowing exploration of a target echo detection space, each measurement being configured with a time window, a pulse train energy level, and a detection ramp profile; and in that a criterion for deciding the chosen measurement is based on the Maximum distance that maximizes the signal-to-noise ratio.

Images