SYSTEM FOR DETERMINING THE VOLUME AND FREE FLOOR AREA IN A LOADING ZONE AND ASSOCIATED CONTROL METHOD

Description

technical field

[0001] The invention has as its technical domain the measurement of the filling of a loading area, and more particularly the measurement of the filling of a skip or trailer of a truck or the holds of a ship. Previous techniques

[0002] From the prior art, we know of documents EP 3534332 and US 2017 / 0228885 disclosing the measurement of the volume of cargo transiting on a loading dock or through the entrance of a truck trailer based on a measurement of the cargo entering the trailer and the cargo exiting the trailer.

[0003] Determining the volume occupied in the trailer does not allow us to determine the available floor space. However, it is the available floor space that determines whether new cargo can be added to the trailer. Indeed, new cargo, particularly in the form of pallets, cannot be placed on top of cargo already present in the trailer. Additions can therefore only be made on a portion of the floor that is free of cargo.

[0004] Furthermore, cargo loaded onto a trailer can vary in shape and height. Methods using acquisition devices positioned at fixed locations cannot determine the available floor space due to shadows and masking effects between cargoes of different shapes. Acquisition devices are generally three-dimensional optical cameras or LiDARs (Light Detection and Ranging), which share the common characteristic of having a wide field of view.

[0005] There is no device that can reliably and systematically determine the floor area in a trailer.

[0006] From document US2014244098, we also know the measurement of the volume of a truck bed as a function of the measurement of the mass added to the vehicle divided by the density of the materials added.

[0007] While such a method is suitable for homogeneous loads, it is no longer appropriate when the materials added to the skip are heterogeneous. This is particularly true in mining operations, for example, with mixtures of soil and ore.

[0008] US 2019 / 0114577 A1 describes a system for determining the free floor area of ​​a loading area comprising LIDAR height sensors fixed to the ceiling of a trailer and directed towards the floor of the loading area and processing means for determining the free floor area from the measurements taken by the sensors.

[0009] Furthermore, filling a skip is generally the result of a decision by the operator in charge of loading regarding the quantity of material to add. Estimating the total mass transported using an average density only allows for the detection of truck overloads relative to the maximum authorized weight. It does not allow for optimizing skip filling, particularly for less dense loads.

[0010] There is no device that can reliably and systematically determine the available volume in a skip or trailer. Description of the invention

[0011] The invention relates to a system for determining the free floor area of ​​a loading zone, comprising drive means, communication means, processing means and a mobile ramp on which are arranged height sensors directed towards the floor of the loading zone at a normal incidence and aligned with each other at a constant height of said floor, the mobile ramp being designed so as to extend in a first direction above the loading zone and being configured so as to move above the loading zone under the effect of the drive means in a second direction, the processing means being configured to determine the free floor area of ​​the loading zone according to the data received from the height sensors via the communication means.

[0012] The mobile ramp may be equipped with at least one depth sensor, powered by the power supply means, and configured to determine the distance to the opposite side of the loading area; the communication means include a connection with each depth sensor.

[0013] The means of communication may include a wireless connection with a local data storage means disposed on the mobile ramp and connected to the height sensors and, where present, to the depth sensors, so as to transmit the data acquired by the sensors when the mobile ramp has finished scanning the loading area.

[0014] Height sensors and depth sensors can be low angle beam distance sensors, preferably LIDARs.

[0015] The drive means may include at least two ropes, each running over an end pulley, to a tension pulley via a right-angle return pulley, the second rope being crossed via an intermediate pulley, the two ropes being set in motion via a drive roller rotated by a drive means.

[0016] The determination system may be equipped with power supply means which may include a battery powering the drive means, the communication means and the processing means, a local battery disposed on the mobile ramp and a contactless power transmission system configured to recharge the local battery of the mobile ramp, a local battery being configured to power the height sensors as well as the depth sensors when the determination system is equipped with them.

[0017] The loading area can be located in a truck, in the bed of a truck, in a truck trailer, in a ship, in a railway wagon, in an aircraft, or in a building.

[0018] The invention also relates to a method for controlling a determination system as described above, comprising the following steps: The height sensors are controlled to acquire measurements; each received measurement is time-stamped according to an internal clock; the drive system is controlled to start the ramp in motion, and the start time of the ramp's movement is recorded; among the received measurements, those whose date falls between the start time of the ramp's movement and the end time of the ramp's movement are determined, equal to the sum of the start time of the ramp's movement and the duration of the ramp's movement; for each measurement from a height sensor, a longitudinal coordinate is then defined as the longitudinal position of the sensor at the time of the measurement.The transverse coordinate is defined as the distance between the height sensor whose measurement is being processed and the first height sensor on the ramp, and the height coordinate is defined as the difference between the trailer's overhead height and the height measurement from the height sensor. The free floor area in the loading zone is determined, and at least one of the following is defined: the free volume in the loading zone, the occupied floor area in the loading zone, the occupied volume in the loading zone, a map of the free floor area as a function image of points whose height coordinate is less than a predetermined threshold, or a map of the occupied floor area as a function image of points whose height coordinate is greater than said predetermined threshold.

[0019] The longitudinal position of a sensor at a stored date can be determined as the average speed of movement of the ramp multiplied by the difference between the stored date and the date the ramp started moving.

[0020] At least one depth sensor can be ordered to acquire measurements, and the longitudinal position of a sensor is determined based on the distance measurement of a first depth sensor directed towards one side of the loading area normal to the direction of movement of the moving ramp.

[0021] The start time of movement of the sensor ramp can be determined as the time of command of the power supply means in order to power the drive means.

[0022] We can control the acquisition of measurements from a current sensor configured to measure the supply current of the drive means, and we determine the start time of movement of the sensor ramp when the supply current of the drive means exceeds a predetermined current threshold.

[0023] For packaged cargo, an elementary area can be associated with each point whose height coordinate is less than the predetermined threshold, the elementary area being equal to the product of the distance between two height sensors along a first direction normal to the movement of the mobile ramp and the distance between two successive measurements along a second direction collinear with the movement of the mobile ramp, then the available floor area can be determined by summing the elementary areas, and the available volume can be determined by multiplying the available floor area by the height of the loading area.

[0024] For packaged cargoes, an elementary area encompassing several measurement points can be determined, the measurements are averaged over each elementary area, the elementary areas for which the average height coordinate is less than the predetermined threshold are determined, then the available floor area can be determined by summing the elementary areas for which the average height coordinate is less than the predetermined threshold, and the available volume can be determined by multiplying the available floor area by the height of the loading area.

[0025] The predetermined threshold can be defined as being less than a minimum cargo size.

[0026] For bulk cargoes, the available volume can be determined as the volume of the loading area less the volume occupied by the cargo determined by integrating the height sensor measurements in the first direction and in the second direction.

[0027] One can determine an occupied floor area or an occupied volume based on measurement points whose height coordinate is greater than the predetermined threshold.

[0028] By measuring the height at normal incidence relative to the floor of a truck trailer, the determination system makes it possible to resolve the deficiencies of the prior art and to determine both the available floor area in a truck trailer or in the hold of a merchant ship and the available volume in a truck tipper or in a bulk hold of a merchant ship. Brief description of the drawings

[0029] Other objects, features and advantages of the invention will become apparent from the following description, given solely by way of non-limiting example and made with reference to the accompanying drawings in which: the figure [ Fig 1 ] illustrates the main elements of a determination system according to the invention, the figures [ Fig 2 ] And [ Fig 4 ] illustrate a longitudinal cross-sectional view of a trailer during pallet loading, the figure [ Fig 3 ] illustrates a top cross-sectional view of a truck trailer showing the layout of the loading area, the figures [ Fig 5 ] And [ Fig 6 ] illustrate the measurement of floor area and available volume for packaged cargo, the figures [ Fig 7 ] And [ Fig 8 ] illustrate the measurement of available volume for bulk cargoes, the figure [ Fig 9] illustrates the arrangement of a mathematical coordinate system for determining the free floor area and volume of a loading zone, the figure [ Fig 10 ] illustrates the main steps of a control method according to the invention, Figure [ Fig 11 ] illustrates the result of determining the free floor area in a trailer. Detailed description

[0030] The system for determining the floor area or available volume in a loading area, when such a loading area is located in a trailer, is illustrated in the figure [ Fig 1 ].

[0031] A loading area is defined as the volume into which packaged or bulk cargo can be added or removed. Generally, a loading area has a parallelepiped shape defined by a floor, two opposite sides, two sides adjacent to the opposite sides, and a ceiling. However, it should be understood that the invention is not limited to a parallelepiped loading area, so other shapes can be considered, including cylindrical, pyramidal, prismatic, etc. Discrete shapes comprising compartments can also be analyzed by the determination system.

[0032] The determination system 1, positioned above and around a loading area 2, comprises a movable ramp 3 on which height sensors 3a are arranged, connected at each end to a slider 4a, 4b. In one embodiment, the movable ramp 3 also includes depth sensors 3b. The height sensors 3a and the depth sensors 3b are narrow-angle distance sensors, preferably LIDARs.

[0033] The 3a height sensors are positioned so that they are directed towards the floor of the loading area (the trailer floor) at a normal angle of incidence, while being aligned with each other and at a constant height above the loading area floor. This arrangement helps to minimize the effects of shadows or obscuration by the loaded cargo.

[0034] The depth sensors 3b are arranged so that at least one is directed towards one side of the loading area perpendicular to the direction of movement of the moving ramp (the bottom of the trailer), and at least one other is directed towards the opposite side of the loading area perpendicular to the direction of movement of the moving ramp (the trailer doors). The direction of the depth sensors 3b is perpendicular to the direction of movement of the moving ramp and, by design, to the bottom of the trailer. In a particular case, such a set of at least one depth sensor 3b directed in one direction and at least one depth sensor 3b directed in the opposite direction is arranged on each side of the sensor ramp 3, as close as possible to the sliders 4a, 4b.

[0035] Sensors 3a, 3b are electrically powered by a local battery 3c.

[0036] Each slider 4a, 4b is designed to support the movable ramp 3 and to move within a listening rail (not shown). Each slider 4a, 4b is set in motion by a cord 5a, 5b contained within a listening rail. The resulting determination system 1 is contained within a small vertical volume, delimited by the listening rails.

[0037] The determining system 1 includes drive means for moving the ropes 5a, 5b to set the movable ramp 3 in motion either towards one side of the loading area, perpendicular to the direction of movement of the movable ramp, or towards the opposite side. In the case of a trailer, the first side is near the bottom of the trailer, the opposite side being next to the trailer doors. Each rope 5a, 5b runs over an end pulley 6a, 6b, to a tension pulley 8a, 8b via a right-angle return pulley 7a, 7b.

[0038] The first tension pulley 8a is connected to a spring 9 which exerts a force on the pulley opposing the tensile force resulting from the tension of the rope. The first rope 5a is thus kept under tension.

[0039] The second rope 5b is crossed via an intermediate pulley 10 before running over the tension pulley 8b. The second tension pulley 8b is also connected to a spring (not shown) like the first tension pulley 8a.

[0040] A drive roller 11, connected to a controlled drive means 12, in particular an electric motor, is positioned between the first rope 5a and the second rope 5b at the first and second drive pulleys 8a and 8b, respectively, so as to drive both ropes simultaneously by contact. Other arrangements could be used, including direct drive of the drive pulleys 8a and 8b. A disengagement device (not shown) is also present and allows the drive pulleys 8a and 8b to be separated in order to break contact with the drive roller 11, particularly during maintenance operations.

[0041] The determination system includes an electronic control unit equipped with power supply means 13, communication means 14 and processing means 15.

[0042] The power supply means 13 provide power to the drive means 12 and the local battery 3c of the ramp 3. These generally consist of a battery and switching means controlled by the processing means 15 and connected to the drive means 12 either directly or via a voltage or power regulator. In certain specific applications, a generator may also be provided to recharge the battery, such as photovoltaic cells or a regenerative braking system at the trailer axles. The generator may also be a battery or an alternator located in the vehicle comprising the loading area or pulling a trailer comprising the loading area.

[0043] In one embodiment, the power supply means 13 are also equipped with a contactless electrical power transmission system, in particular an inductive charging system, so as to be able to charge the local battery 3c supplying the sensors 3a, 3b of the sensor array 3, when the drive means are stopped. The array 3 is then of simpler design because it is not necessary to provide a power cable and means for guiding said power cable when the array 3 is moved.

[0044] The communication means 14 are powered by the power supply means 13 and connected to each sensor 3a, 3b as well as to the power supply means 13. The connection to the sensors 3a, 3b is wired or wireless, preferably of the Wi-Fi, Bluetooth, etc. type. As with the contactless electrical power transmission system, a wireless connection allows for a simpler design of the ramp 3 because it is not necessary to provide data connection cables and means for guiding said data connection cable when the ramp 3 is moving. In the specific case of a wireless connection, the communication means 14 include a local data storage means located on the mobile ramp 3 and through which the data from the sensors 3a, 3b are transmitted. The local data storage means stores the data acquired by the sensors 3a, 3b until the mobile ramp has finished scanning the loading area.The stored data is then transmitted via processing method 15.

[0045] The connection with the power supply means 13 allows commands to be transmitted to the power supply of the drive means 12 from the processing means 15 and / or the current measurements of the power supply of the drive means 12 to the processing means 15 to be transmitted.

[0046] The means of communication 14 also include a connection to a mobile telephone network or a satellite telephone network enabling the transmission of the free floor area or free volume.

[0047] The processing means 15, such as a processor associated with memory, are connected to the communication means 14 by a data connection, in particular a CAN data bus, and electrically powered by the power supply means 13.

[0048] In the specific case of truck trailers, the trailer is loaded either by pallet jack or forklift. These machines lift the pallets for moving and loading. As a result, the height of the pallets loaded in the trailer is limited to the trailer's ceiling height minus the lifting height. The lifting height is generally 10 cm. However, other heights can be considered.

[0049] The figure [ Fig 2 Figure ] illustrates a cross-sectional view of a trailer during the loading of palletized cargo. The trailer 20 includes a floor 21, a ceiling 22, a trailer bottom 23, and doors 24. Figure [ Fig 2 [The diagram also illustrates palletized loads 25a being loaded and a palletized load 25b being loaded. For clarity, the lifting equipment used to lift the palletized load 25b is not shown.]

[0050] The figure [ Fig 2This clearly illustrates that the maximum cargo height hC is equal to the trailer's overhead height hSP minus the lifting height hL. Once the cargo is loaded, a clear space with a height at least equal to the maximum height hL is thus created above each loaded cargo 25a. In other words, the loading area 2 has a height equal to the maximum cargo height hC when the cargo is placed on the floor of the loading area.

[0051] Thanks to the reduced vertical volume required by the determination system 1, it is then possible to place the determination system in contact with the ceiling of the trailer in the free space available above each load.

[0052] The figure [ Fig 3 ] illustrates a top cross-sectional view of a truck trailer 20, comprising two doors 24a,24b, two side walls 32a,32b and a trailer bottom wall 23.

[0053] A trailer 20 typically has a parallelepiped shape. However, near the trailer's rear wall 23, the trailer has a prismatic shape resulting from the removal of triangular-based zones 34a, 34b. This prismatic shape and the removal of the triangular-based zones 34a, 34b are used to maintain the turning radius of the tractor pulling the trailer. Indeed, the tractor is generally positioned as close as possible to the trailer's rear to improve compactness, aerodynamics, and to facilitate the connection of electrical and pneumatic cables between the tractor and the trailer.

[0054] It follows from the shape of the trailer floor that the area available for loading cargo, defined above as the loading area, is limited relative to the trailer floor area. The loading area 2 is limited in depth at the trailer floor wall by the depth of the triangular-based zones 34a, 34b, and at the doors 24a, 24b by the thickness of the doors. The loading area 2 is limited in width on each side by the width of each of the triangular-based zones 34a, 34b.

[0055] We then define a free surface equal to the surface of the trailer less the surface of the loading area, comprising a first surface 35a in contact with a first side wall 32a, a second surface 35b in contact with a second side wall 32b and a third surface 35c in contact with the bottom of the trailer 23.

[0056] In view of the figure [ Fig 3It will be understood that the depth sensors 3b are preferentially positioned as close as possible to the sliders 4a, 4b, but opposite the wall 23 of the trailer floor located between the two triangular-based zones 34a, 34b. This arrangement avoids the need to reprocess the measurements from the depth sensors 3b to compensate for the difference in depth between the measurement point on the truncated surface between the trailer floor wall 23 and the side walls 32a, 32b.

[0057] The figure [ Fig 4 ], is identical in all respects to the figure [ Fig 2 ] but also illustrates the free space at the bottom of the trailer corresponding to the third free surface 35c of the figure [ Fig 3 ].

[0058] The measurement system 1 is located in the free volume extending in a direction normal to the free surface of the trailer up to the trailer ceiling. The listening rails and pulleys 6a, 6b, 7a, 7b are located in the volumes corresponding to the first and second surfaces 35a, 35b. The drive means 8a, 8b, 9, 10, 11, 12, the power supply means 13, the communication means 14, the processing means 15, and the mobile ramp 3 at rest (i.e., when no measurement is being taken) are located in the free volume corresponding to the third surface 35c. In other words, the measurement system 1 is located in the free volume extending on either side of the loading area while remaining within the height of the loading area.

[0059] During the measurement, each height sensor 3a measures the distance between the sensor array 3 and either a packaged cargo 50, a bulk cargo 60, or the loading area floor 21. It should be understood that other forms of packaging can be considered instead of a pallet. Examples include drums, cartons, etc.

[0060] The figures [ Fig 5 ] And [ Fig 6 ] illustrate the measurement of floor area and available volume for packaged cargo, such as pallets, drums or cartons.

[0061] Ramp 3 is moved along the length of the loading area while height sensors 3a acquire values. The measured heights depend on the presence or absence of cargo 50,60, and when cargo 50,60 is present, on its height.

[0062] The available floor area is determined by comparing the measured points to a predetermined threshold.

[0063] The available volume is then determined by multiplying the available floor area by the maximum cargo height hC defined in figure [ Fig 2 ].

[0064] The figures [ Fig 7 ] And [ Fig 8 ] illustrate the measurement of available volume for bulk cargoes.

[0065] Ramp 3 is moved along the length of the loading area while height sensors 3a acquire values. The measured heights depend on the amount of cargo at each measurement point.

[0066] For such cargoes, determining the available floor area is not relevant. The occupied volume is then determined directly by integrating the measured height with respect to the width and length of the loading area. An integration with respect to the width of the loading area is illustrated in Figure [ Fig 8 The available volume is then determined by subtracting the determined occupied volume from the total loading area volume.

[0067] In the figure [ Fig 7 It will be understood that the surface area of ​​the bulk cargo varies more or less between each measurement step, depending on the nature of the cargo. Sand will tend to exhibit smaller differences in level than rocks.

[0068] As a preamble to the presentation of the main steps of the control process, a coordinate system (O,x,y,z) is defined, in which the origin O is fixed in the left corner at the junction between the floor and two adjacent sides of the loading area. In a trailer, such a coordinate system implies that the plane (O,x,z) includes the first height sensor 3a of ramp 3. Figure [ Fig 9[ ] illustrates such a coordinate system. The longitudinal direction x is collinear with the length of the trailer, increasing from the trailer floor towards the trailer doors. The transverse direction y is collinear with the width of the trailer, increasing from left to right. The height direction z is collinear with the height of the trailer, increasing from the floor to the ceiling. Another coordinate system could be chosen. However, the coordinate system described above simplifies the calculations described below in the case of a scan of the loading area in the direction of increasing longitudinal coordinates and an increasing identification of the height sensors 3a in the direction of increasing transverse coordinates. The described coordinate system must be adapted or the calculations modified if a different displacement is considered or if a different identification of the height sensors 3a is envisaged.

[0069] These determinations will now be specified within the framework of the description of the control process, including the steps illustrated in Figure [ Fig 10 ].

[0070] The control method for the determination system 1 is stored in at least one memory of the processing means 15, and executed by the processor of the processing means 15.

[0071] In a first step 101, the height sensors 3a and the depth sensors 3b are activated to acquire measurements. Each height sensor 3a and each depth sensor 3b is equipped with a housing containing a lens or an aperture, depending on the measurement technique used. The height or depth measurement is then taken perpendicularly to the surface of the housing through the lens or aperture. Each height sensor 3a and each depth sensor 3b outputs a measured distance associated with an identifier that allows each sensor to be distinguished on the ramp 3. The sensor data is received by the communication means 14 and transmitted to the processing means 15. The processing means 15 stores each received measurement in its memory, associating it with the identifier of the corresponding sensor and the time of reception determined according to an internal clock.Such a clock is notably included in software or hardware in the computing means 15.

[0072] In a second step 102, the power supply means 13 are controlled via the communication means 14 so that the drive means 12 is powered. The ramp is then set in motion. The start time of the movement of the sensor ramp 3 is determined as the time of the control of the power supply to the drive means 12. In a particular embodiment, the acquisition of measurements from a current sensor configured to measure the supply current of the drive means 12 is controlled, and the start time of the movement of the sensor ramp 3 is determined when the supply current of the drive means 12 exceeds a predetermined current threshold.

[0073] In a third step 103, it is determined whether the travel time of the sensor array 3 has elapsed. The travel time of the array is equal to the ratio of the length that can be traveled by the sensor array 3 divided by the average travel speed, determined by design or by testing and stored in the computing means 15. When this is the case, the height sensors 3a are controlled to stop their acquisitions. This extends the autonomy of the local battery 3c.

[0074] In a fourth step 104, the available floor area and available volume of the loading area are determined by carrying out the following sub-steps.

[0075] In substep 104a, among the received measurements, those whose date is between the start date of ramp movement and the end date of ramp movement are determined to be equal to the sum of the start date of ramp movement and the duration of ramp movement.

[0076] For each measurement of a 3a height sensor whose date is between the start date of ramp movement and the end date of ramp movement, the longitudinal coordinate x is then defined as the distance between the position of the sensor during the measurement and the first side of the loading area.

[0077] In a first embodiment, the longitudinal coordinate x is determined as being equal to the average speed of movement of ramp 3 multiplied by the difference between the stored date and the start date of movement of the ramp.

[0078] In another embodiment, the longitudinal coordinate x is determined to be equal to the sum of the depth measurement of the depth sensor directed towards the first side of the loading area and the offset along the longitudinal direction x between the objective of the depth sensor 3b and the objective of the height sensor 3a which performed the measurement.

[0079] In yet another embodiment, the longitudinal coordinate x is determined to be equal to the difference between the depth of the loading area and the sum of the depth measurement and the offset along the longitudinal direction x between the lens of the depth sensor 3b, directed towards the side opposite the first side of the loading area, and the lens of the height sensor 3a, which performed the measurement. The depth of the loading area is defined as the distance between the first side of the loading area and the opposite side. In a trailer, the distances between the sides of the loading area and the trailer walls must be taken into account.

[0080] It should be noted that these embodiments are not mutually exclusive and that the longitudinal coordinates determined according to one of the above embodiments can be compared to each other to determine an erroneous value, notably by a three-way voting mechanism. This provides additional robustness regarding the determination of the longitudinal x-coordinate to determination system 1.

[0081] The transverse y-coordinate is defined as the distance between the height sensor whose measurement is being processed and the first height sensor 3a on the ramp. This distance is known by design based on the spacing of the height sensors 3a on the ramp. By construction, the transverse y-coordinate of the first sensor 3a on the ramp is zero. However, other values ​​for the transverse y-coordinate of the first sensor can be chosen. These values ​​must be taken into account in the coordinate calculation as an offset value.

[0082] The height coordinate z is defined as the difference between the height of the loading area and the height measurement of the height sensor 3a. In a particular embodiment, an absolute height coordinate z is determined by subtracting the distance between the lens or the aperture of the height sensor 3a and the height of the loading area.

[0083] For packaged cargo, the available floor area and available volume are determined by carrying out the following substeps 104b to 104e.

[0084] In substep 104b, points are determined whose height coordinate z is less than a predetermined threshold. In a preferred embodiment, the predetermined threshold is less than the thickness of a pallet. Alternatively, for practical reasons, the lifting height defined previously and generally equal to 10 cm may be chosen. Figure [ Fig 11 ] illustrates the cargo layout mapping 50 resulting from this determination for the layout illustrated previously by the figure [ Fig 5Each disk represents a point of a height measurement taken by a height sensor 3a. It should be understood that the number and arrangement of these measurements are intended only to illustrate the description of the determination. Other numbers of measurements and other measurement patterns are conceivable and fall within the scope of the invention.

[0085] In a particular embodiment, a minimum cargo size greater than the pallet thickness or lifting height may be taken into account. This is especially relevant when drums or containers are loaded in the loading area. A different predetermined threshold may then be chosen.

[0086] In another embodiment, intermediate occupancy areas can be determined by comparing the z coordinates to a second predetermined threshold.

[0087] In substep 104c, an elementary surface is then associated with each point whose coordinate is less than the predetermined threshold. An elementary surface is equal to the product of the distance between two height sensors 3a along the transverse y direction and the distance between two successive measurements along the longitudinal x direction.

[0088] In a substep 104d, the available floor area is determined by determining the number of points whose height coordinate z is less than the predetermined threshold and multiplying this number by the elementary area.

[0089] In substep 104e, the available volume is determined by multiplying the available floor area by the height of the loading area.

[0090] It will be understood that, following these steps, we simultaneously have the available floor area, the available volume, and the distribution of cargo within the loading area. It is then possible to optimize cargo placement after performing shape recognition on the free floor areas.

[0091] For bulk cargoes, the available volume is determined by carrying out the following sub-steps.

[0092] At the end of substep 104a, the process continues with a substep 104f, during which the volume occupied by the cargo is determined by integrating the heights of each measurement along the longitudinal direction x and the transverse direction y.

[0093] The available volume is determined by subtracting the volume occupied by the cargo from the total volume of the loading area.

[0094] The determination system and control method have been described above in relation to a movable ramp. It will be understood that the movable ramp can have additional functions, such as deploying or retracting a removable cover. In some embodiments, the sensors and elements arranged on the movable ramp are located on a removable cover hoop, preferably the first hoop of a removable cover. The removable cover hoop then forms a movable ramp as defined in this description. The sensors then scan the loading area when the removable cover is opened or closed.

[0095] Similarly, it will be understood from reading the description above that the processing means can be local, remote or distributed between local and remote means.

[0096] The determination system and the corresponding control method have been described and illustrated for measuring the free floor area of ​​a loading zone, particularly in a truck trailer. However, the invention also includes measuring the free floor area or free volume of a loading zone in absolute terms and in a truck without a trailer, in an aircraft, in a ship, or in any vehicle equipped with a loading zone in which goods are loaded or unloaded.

[0097] The determination system and the control process can also be applied to buildings such as logistics centers or warehouses.

[0098] Furthermore, it is clear from the above description that the determination of free floor area or free volume in the case of bulk cargo is carried out completely autonomously without requiring human intervention. The invention also includes a determination system and control method applied to autonomous vehicles. For these applications, reference should be made in particular to French patent application FR1759675 filed by the applicant, which describes the actuation of a removable cover based on the GPS position of a vehicle. Reference should also be made to French patent application FR1759676, also filed by the applicant, which describes the determination and transmission of the occupied floor area and volume in a vehicle and its rerouting based on, on the one hand, the received data and, on the other hand, cargo compatible with the vehicle's position, free floor area, and / or free volume.

Claims

1. System for determining the free floor area of a loading zone (2), comprising drive means (12), communication means (14), processing means (15) and a moving beam (3) on which height sensors (3a) are arranged that are directed towards the floor of the loading zone (2) at normal incidence and aligned with one another at a constant height from said floor, the moving beam (3) being designed so as to extend in a first direction above the loading zone and being configured so as to move above the loading zone (2) when driven by the drive means (12) in a second direction, the processing means (15) being configured to determine at least the free floor area of the loading zone (2) according to the data received from the height sensors (3a) via the communication means (12).

2. Determination system according to claim 1, wherein the moving beam (3) is provided with at least one depth sensor (3b), powered by the power supply means (13), and configured to determine the distance on the opposite side of the loading zone, the communication means (14) comprise a connection to each depth sensor (3b).

3. Determination system according to either claim 1 or claim 2, wherein the communication means (14) comprise a wireless connection with a local data storage means arranged on the moving beam and connected to the height sensors (3a) and, when present, to the depth sensors (3b), so as to transmit data acquired by the sensors when the moving beam (3) has completed scanning the loading zone (2).

4. Determination system according to any one of claims 1 to 3, wherein the height sensors (3a) and the depth sensors (3b) are small aperture angle distance sensors, preferably LIDARs.

5. Determination system according to any one of claims 1 to 4, wherein the drive means comprise at least two ropes (5a, 5b) each running along an end pulley (6a, 6b), towards a tension pulley (8a, 8b) by means of an angle return pulley (7a, 7b), the second rope (5b) being crossed by means of an intermediate pulley (10), the two ropes being set in motion by means of a drive roller (11) rotated by a drive means (12).

6. Determination system according to any one of claims 1 to 5, provided with power supply means (13) comprising a battery supplying power to the drive means (12), the communication means (14) and the processing means (15), a local battery (3c) arranged on the moving beam (3) and a contactless power transmission system configured to recharge the local battery (3c) of the moving beam (3), the local battery (3c) being configured to supply power to the height sensors (3a) and depth sensors (3b) when the determination system is provided with it.

7. Determination system according to any one of claims 1 to 6, wherein the loading zone (2) is located in a truck, in a truck hopper, in a truck trailer, in a ship, in a railway car, in an aircraft, or in a building.

8. Control method for a determination system according to any one of claims 1 to 7, comprising the following steps: a. the height sensors (3a) are controlled so as to acquire measurements, b. each measurement received is dated according to an internal clock, c. the drive means (12) is controlled so that the beam starts to move and the start time of movement of the beam (3) is stored, d. among the received measurements, those whose date is between the start date of movement of the beam and the end date of movement of the beam equal to the sum of the start date of movement of the beam and the duration of movement of the beam, are determined, e. for each measurement of a height sensor (3a), a longitudinal coordinate is then defined as the longitudinal position of the sensor at the time of the measurement, the transverse coordinate is defined as the distance between the height sensor whose measurement is processed and the first height sensor (3a) of the beam and the height coordinate is defined as the difference between the ceiling height of the trailer minus the height measurement of the height sensor (3a), f. the free floor area is determined in the loading zone and at least one of the free volume in the loading zone, the occupied floor area in the loading zone, the occupied volume in the loading zone, a mapping of the free floor area as an image according to the points of which the height coordinate is less than a predetermined threshold, or a mapping of the occupied floor area as an image according to the points of which the height coordinate is greater than said predetermined threshold.

9. Control method according to claim 8, wherein the longitudinal position of a sensor on a stored date is determined as the average moving speed of the beam (3) multiplied by the difference between the stored date and the start date of movement of the beam.

10. Control method according to claim 8, wherein at least one depth sensor (3b) is controlled so as to acquire measurements and the longitudinal position of a sensor is determined according to the distance measurement of a first depth sensor (3b) directed towards a side of the loading zone normal to the direction of movement of the moving beam (3).

11. Control method according to any one of claims 8 to 10, wherein the start time of movement of the sensor beam (3) is determined as the time at which the power supply means (13) are controlled in order to supply power to the drive means (12).

12. Control method according to any one of claims 8 to 11, wherein the measurement acquisition of a current sensor configured so as to measure the power supply current of the drive means (12) is controlled, and the start time of movement of the sensor beam (3) is determined when the power supply current of the drive means (12) exceeds a predetermined current threshold.

13. Control method according to any one of claims 8 to 12, wherein, for packaged cargoes, a. an elementary area is associated with each point whose height coordinate is less than the predetermined threshold, the elementary area being equal to the product of the distance between two height sensors (3a) in a first direction normal to the movement of the moving beam (3) and the distance between two successive measurements in a second direction collinear to the movement of the moving beam (3), then b. the available floor area is determined by adding up the elementary areas, and c. the available volume is determined by multiplying the available floor area by the height of the loading zone.

14. Control method according to any one of claims 8 to 12, wherein, for packaged cargoes, a. an elementary area including a plurality of measurement points is determined, measurements are averaged over each elementary area, the elementary areas for which the average height coordinate is less than the predetermined threshold are determined, then b. the available floor area is determined by adding up the elementary areas for which the average height coordinate is less than the predetermined threshold, and c. the available volume is determined by multiplying the available floor area by the height of the loading zone.

15. Control method according to any one of claims 8 to 14, wherein the predetermined threshold is defined as being less than a minimum size of the cargoes.

16. Control method according to any one of claims 8 to 12, wherein, for bulk cargoes, the available volume can be determined as the volume of the loading zone minus the volume occupied by the determined cargo by integrating the height sensor (3a) measurements in the first direction and in the second direction.

17. Control method according to any one of claims 8 to 16, wherein an occupied floor area or an occupied volume are determined depending on measurement points whose height coordinate is greater than the predetermined threshold.