LU100980B1

LU100980B1 - System and method for handling containers

Info

Publication number: LU100980B1
Application number: LU100980A
Authority: LU
Inventors: Emile Simon
Original assignee: Luxembourg Inst Science & Tech List
Priority date: 2018-11-09
Filing date: 2018-11-09
Publication date: 2020-05-11
Also published as: WO2020094665A1; EP3877919A1

Abstract

The invention relates to a system and a method for handling containers in accordance with an optimization process. Waste containers on a construction or demolition site may occupy a large area on the ground and their evacuation to a waste treatment facility may produce a substantive amount of pollution. The present invention aims at optimizing the choice of containers used to minimize both the surface on the ground needed for receiving the containers and the pollution produced.

Description

SYSTEM AND METHOD FOR HANDLING CONTAINERS Description Technical field

[0001] The invention is directed to a method and a system for handling containers and more specifically to the selection of containers aiming at receiving waste generated by a construction or demolition site.

Background art

[0002] The standard practice for managing waste on a construction or demolition site is to provide the site with a collection zone where waste containers wait for being filled by respective type of waste before being removed and sent to a waste treatment facility. The collection zone needs to be big enough so as to receive many containers. Depending on the schedule of construction or demolition, not all containers are needed at one particular point in time and thus some containers may unnecessary occupy some surface on the ground. In most of the construction/deconstruction sites, space management is critical due to limited amount of space for the construction/demolition site and for the collection zone. For instance, this often occurs for construction/deconstruction sites in city centres or for offshore (e.g. oil or gas) platforms. The obvious solution to this problem has shown to be the provision of smaller containers which are more often transported to the waste treatment facility. However, this solution generates a higher amount of work for truck drivers (or other transportation means) and the accompanying drawbacks: traffic, fleet of transportation means, pollution, safety and costs. In particular, during construction/deconstruction sites, traffic management is also an important constraint that needs to be dealt with. The traffic management operations cover the traffic inside the construction/deconstruction site and the collection zone, but also the traffic outside the site and collection zone. Recent technical advances for a better management of construction/deconstruction projects and sites are based on Information Technologies. For instance, BIM (Building information modelling) models can extend to the the management of the construction sites (including space and time constraints such as blueprints and timewise planning).

Real-time connectivity with those models may be ensured by applications on tablet or smartphones that are used by workers or even by foremen on the construction/deconstruction site itself. The standard practice for managing waste is in essence quite different from managing raw materials, semi-finished and finished products used in production sites or in logistics processes. For instance, in a regular manufacturing process, precise specifications (size, weight, composition of materials, quantity, and any other physical properties, ...) are known during the production process or the logistics processes. By contrast, waste production processes (e.g. processes of demolition), may not have precise specifications about the material decommissioned and the waste material produced, even in case of reverse logistics processes (e.g. in consumer electronics).

[0003] While trying to address some aspects of the issues in relation to waste collection, some have investigated the location of collection points. For example, Mehr (“Planning Solid Waste Collection with Robust Optimization: Location-Allocation, Receptacle Type, and Service Frequency”, Advances in Operations Research, Vol. 2018, Article ID 2912483) investigates the location of dumpsters or compactors in an urban situation, as well as the number of waste receptacles to be placed at each waste collection point. This paper is however silent about the need to provide a compact area for collection of waste in a construction/demolition site and the need to reduce fossil fuel emissions.

Summary of invention Technical Problem

[0004] The invention has for technical problem to address the drawbacks as stated above and in particular to provide a system and a method which enable a construction or demolition site to work more efficiently and more safely.

Technical solution

[0005] The invention is directed to a method in accordance with claim 1 and a system in accordance with claim 16.

[0006] More particularly, the invention concerns a method for the management of a container handling system, the system comprising: - a plurality of containers, preferably waste containers, waste bins, skips, boxes, bags, or barrels, at least two of which having different footprints: - a collection zone used for the gathering of at least some of the containers; - a source remote from the collection zone and generating a pre- determined amount of waste material of one or more types as a function of time, the source being a construction/demolition site or part of a construction/demolition site; - at least one waste treatment facility, remote from the coliection zone; - first transportation means for transporting waste to the containers or to the waste treatment facility; - second transportation means for transporting the containers from/to the collection zone; the first and second transportation means moving along paths which define respective distances between the collection zone and the source or between the waste treatment facility and the collection zone; the method comprising a step of determination of the amount and type of material generated by the source and a step of allocation, by a computer- implemented management system, of at least one of the containers to each material, the allocation being made such that one or several container(s) of a given type may be allocated to none, to one or to more than one types of material; and the allocation is performed according to an optimisation process that performs an optimal selection of containers, which can be of different types, which optimization aims at minimizing the following two performance criteria: : - the sum of footprints of the containers to be stored at any point in time in the collection zone to receive the predetermined amount of waste;

- the overall distance travelled by the second transportation means between the collection zone and the waste treatment facility for gathering the entirety of the amount of waste: the management system generating an output comprising: - an optimal selection of containers minimising the overall distance while the sum of footprints remains below a predetermined threshold, if such a selection exists; or - an optimal selection of containers minimising the sum of the footprints while the overall distance remains below a predetermined threshold, if such a selection exists; or - a default optimal selection of containers minimising a given weighted sum of both above-mentioned criteria; or - a set of selections of containers which consists in trade-offs between both criteria in accordance with pre-set weights or pre-set acceptable ranges allowed for the criteria, the output consisting in this case in the selections of containers together with the values of the above- mentioned criteria obtained from such selections, Optionally, the method comprises the step of performing the collection of waste in accordance with said optimal selection minimising the distance, or in accordance with said optimal selection minimising the sum of footprints if an optimal selection minimising the distance does not exist, or in accordance with said defauit optimal selection if both selections minimising distance and sum of footprints do not exist, or optionally, if so decided by a user, the step can perform the collection of waste in accordance with a selection of containers chosen by a user amongst the set of selections of containers. Definitions

[0007] The terminology “footprint” is to be understood as the area on the ground necessary for a particular container. If the container has a slanted wall, the area takes this wall into consideration (by computing, for instance, the projection on the surface). Also, some room may be needed around acontainer for safety or handling reasons, or for loading or unloading the container. Hence, a safety factor can be applied to the physical area occupied on the ground by the container. This safety factor can depend on the type, volume or dimension of the container or its intended use (type of waste that are received in the container).

[0008] The “collection zone” is an area arranged nearby or on the construction or demolition site that is dedicated for waste collection. During the construction or demolition process, this area can be relocated at different places and its size can vary according to the time-varying needs of the construction/deconstruction site.

[0009] The “type” of material that is dealt with on a construction or demolition site can be very diverse, such as, among others: concrete, plastics, wood, metal, glass, toxic waste or waste which needs to be handled according to specific regulation, solid, particulate material, liquid, gaseous, etc.

[0010] The “first transportation means” handle the waste directly. These may be construction trucks, cranes, forklifts, workers, etc. The main role of these first transportation means is to gather the waste into the containers on the collection zone of the construction site. For some very specific waste that are too big or inappropriate to be handled through containers, the “first transportation means” can bring the waste directly to the waste treatment facility.

[0011] The “waste treatment facility” is to be understood in its widest meaning. It can be a place where one or more of the following activities are performed: recycling, reuse, reprocessing, refurbishment, disposal, repair, remanufacturing, disposal in sanitary landfill, etc.

[0012] The “determination” of the amount of material can be a process of determination based on objective data or an estimation with a certain degree of confidence, not taking account of all the data available but optimizing the time for calculation by omitting some less relevant data. The predetermined amount of material can also be dictated by the technical documentation of a call for tender or estimated by an external party (architect, head of the construction/demolition site, etc.). Thispredetermined amount can also be used while performing the initial blueprint of the construction/demolition site. Such determination is made prior to the execution of the present invention, as this determined amount of materials is a data input fed into the invention. It should be noted that this determination itself can be made by humans, but it can also be made automatically with processing methods known in the art.

[0013] The first criterion” to be optimized is the space on the ground occupied by the containers. The need for containers is governed by the production of waste which can be assessed while planning the construction or demolition. This first criterion aims at minimising the total footprint of all containers present on the construction/demolition site at each given point in time.

[0014] The “second criterion” to be optimized is the distance travelled by the “second transportation means” to transport the containers from/to the collection zone. Generally speaking, the higher the overall distance, the higher the CO2 emitted or energy used by the transportation means. In that sense, the overall distance is to be understood as a technical value used to approximate the calculation of the amount of CO2 emitted. This approximate CO2 amount estimation can be improved by other models well known in the art (transportation domain literature), leveraging various known technical values (such as the weight of the transportation means, the weight of the containers and materials being transported, the type of routes taken, the age or ecological class of the transportation mean,...).

[0015] Optionally, the distance travelled by the first transportation means from the part of the construction/demolition site where the waste is produced to the containers can also be taken into account. Hence, all transportation means in all directions can be calculated and optimized.

[0016] It has to be noted that the optimization is a finite process that is calculated on the basis of a finite system. A definite number of containers are available in a pool of containers. A pre-determined amount of waste material is to be handled. All this happens according to a timewise planning which can be estimated in advance. The planning can describe the sequence of operations, the constraints, duration, date/time ofoccurrence of each operation. The first criterion, i.e. the surface on the ground of the collection zone, can be optimized for every moment during the lifetime of the construction or demolition. The second criterion can be optimized for the total amount of distance travelled. Hence, both criteria can be optimized on a different scale of time.

[0017] The method is looking for optimal solutions of selections of containers where the type of containers to be used for each type of material and optionally in which sequence (and/or planning) during the construction/demolition are defined.

[0018] A first optimal selection of containers, minimising the overall distance travelled by the second transportation means can be looked for. This selection must however be such that the sum of footprints remains within a predetermined threshold. This known value can be dictated by an architect or head of the construction/demolition project.

[0019] A second optimal selection, if such a first optimal selection cannot be obtained, aims at minimising the sum of footprints while keeping the overall distance travelled by the second transportation means below a predetermined threshold value. This latter threshold can be decided by external actors, such as local authorities or regulations, such as for example consequently to an allowed amount of CO2 allocated to the construction/demolition site.

[0020] If neither of the former and latter optimal selection can be obtained, the system defines a default optimal selection of containers, where the weighted sum of the two criteria is minimised. The quantity to be minimized can be expressed as a linear combination of the two criteria such as A.overall distance + (1-\).sum of footprints, where À is in the range [0,1]. The criteria can be normalized (divided by an average value) so that by using % as default value for A, an equal importance is given to both criteria.

[0021] Optionally, the system outputs one or several trade-off solutions. A value of the two criteria can be calculated for each solution: the minimum area of the collection zone X, and the total distance travelled Y. The user maychoose to affect more weight to the size of the zone and then will choose a solution with a smaller X. Alternatively, the choice may be for criterion Y. A ratio (for instance 30%-70%) can be given to each criterion to help the user choose an optimal solution which fits his/her needs. Also, a limit of acceptable value can be defined: for instance, external regulation can specify/require technical constraints, such as, that the size of the collection waste does not exceed a certain value, or that the amount of CO2 (linked to the distance travelled) shall be less than a particular threshold. All these aspects can be taken into account while choosing one of the solutions presented by the system to the user.

[0022] The method and system of the present invention may also be used to help establish a cost estimation of all necessary operations of the construction/demolition site in relation with waste management. Indeed, on the basis of the selection of containers, a further step of calculation of a total cost to use the containers can be performed, by adding the costs involved to use each container. Several of the aspects involved behind the costs of use of a container can be captured with known technical values, such as man-hour costs, containers price amortisation, transportation means fuel, duration and space needed for the operations, the availability of auxiliary tools for the operation, maintenance, ...

[0023] Knowing the costs inferred by the use of each container also allows to integrate this parameter as a further criterion within the selection process. As far as a cost can be determined with known technical values, a so- called technical cost, then that technical cost can be optimized by the present invention at the same time and in the same manner as the overall distance and the sum of footprints. Similarly, a technical CO2 estimation obtained with only known technical values could be optimized at the same time than, or instead of, the overall distance. Considering this, the step of the process which searches for an optimal selection of containers can include the technical cost corresponding to each container as a further criterion (further to the footprint and overall distance and/or technical CO2) and a linear combination of all three (or four) criteria with various factors

M1, À2, (A3,) and (1-A1-A2(-A3)) for instance, can be allocated to these three (or four) criteria respectively.

Preferred embodiment

[0024] The method and the system of the invention may contain optionally the features of the dependent claims.

[0025] Thus, according to a preferred embodiment, the method or the system can comprise any of the following features, taken alone or according to any possible combination: - The pre-determined amount of material is generated by a digital model integrating a schedule of operations to be performed on the construction/demolition site and/or a building information model. Indeed, through appropriate communication means, a BIM (building information model) can assess the amount of waste material that will be produced during construction/demolition and these data can be directly communicated to the container handling system according to the invention. The amount of waste can be calculated with an expansion factor, since waste material extracted from a building being demolished will typically occupy a larger volume than the same material before the construction of this building.

- The pre-determined amount of material is sequentially updated in accordance with the detected amount of waste material already in the containers or already sent to the waste treatment facility, or in accordance with information sent by the digital model, and the optimized selection of containers is recalculated according to this update. Indeed, the initial pre- determined amount of waste material of each type constitutes an estimation. During construction or demolition, some random events may affect the type and amount of waste material that is produced. By contrast to a manufacturing process that is controlled and that produces expected quantity of products, a construction or demolition site may be impacted with random and unexpected events: the discovery of unexpected material in the ground, schedule delay due to weather conditions, etc. It is thusimportant for the reliability of the process to re-assess the type of waste material and the amount of material during the lifetime of the construction/demolition.

Thus, a feedback loop is created to measure the amount of material already evacuated and to reassess the choice of containers to maintain the optimal conditions.

Several sensors can be foreseen in the containers (volume sensor, camera, scale, etc.) or at the waste treatment facility, to measure the amount of waste material already evacuated.

The re-assessment can also be derived from the BIM model or the real-time planning digital model of the construction/demolition.

For example, if a construction site is in advance on its initial schedule, the criteria of optimization may lead to a different optimum choice of containers for the remaining of the construction/demolition.

Usually, weekly construction site meetings output a description of gaps between the planning and the current on-site situation and leads to modifications of the planning.

Those reports can be used as input for the feedback loop.

Hence, the sequential reassessment allows to always maintain the optimal situation. - The pre-determined amount of waste is expressed as a range of values for each type of material and for a predetermined time frame.

The terminology “range of values” is to be understood in its widest meaning, i.e. a statistical range with a lower and a higher value, between which there is high odds (for instance 80%) that a particular type of waste will be produced within a particular period of time. - The amount of waste varies as a function of time and the optimization is made for a given timeframe.

The timeframe for which the optimization is made may be the entirety of the construction/demolition period.

It may also be shorter time periods.

The result of the optimization may not be the same depending on the timeframe that is considered.

Usual timeframes are a week or a day. - The containers have a capacity of between 1 and 30 m3. - The transportation means are autonomous vehicles, such as trucks, airborne vehicles or waterborne vehicles.

Optionally, the method or the system of the invention involves the automatic control or monitoring of themovement of the autonomous transportation means.

Optionally the method or the system can manage the movements of the autonomous transportation means.

The transportation means can be controlled to automatically pick the appropriate containers at the location where the pool of containers are stored, bring them to appropriate position in the collection zone, and transport them to the waste treatment facility, when (at least partially) loaded with waste material. - There are at least thirty containers of different footprint.

Thus, there may be millions of possible selections of containers, among which only a few make it possible to reach optimal conditions.

For particular initial conditions, there may be only a few containers out of these thirty different types of containers, which suit the best solution.

Alternatively or in complement, there are at least thirty containers of different types.

Each container can be adapted to receive one or more type of waste material, such as for instance wood, iron, bricks, etc. - The optimization process is at least partially performed by brute force computation.

In other words, for every single possible combination of containers, a calculation of the distance and square meters for the collection zone are calculated.

Only the combinations showing the best results (so called non-dominated points, i.e. that belong to the so-called Pareto-front of optimal solutions) are kept as potential solutions for optimal selection. - The optimization process is at least partially performed through heuristic processes or known methods from numerical optimization models.

Alternatively or complementarily, methods known in the arts of Mixed- integer or combinatorial optimisation (such as branch-and-bounds type) can be used. - The optimization process also attempts to minimise the total number of containers and/or number of transportation means and/or number of trips required for transporting the entirety of the pre-determined material from the source to the collection zone and/or from the collection zone to the waste treatment facility.

- The optimization process takes also into consideration the lower and upper values of the range of material, in order to perform an optimization returning at least one optimal selection of containers that is optimal over the whole range of expected values for each said material.

This aspect makes it possible to propose robust and efficient solutions.

The optimization is hereby robust against uncertainties related to the amount of waste material actually produced. - The optimization process takes also into consideration further constraints forming further criteria for the optimization process, such as: the cost per hour of immobilisation of a container in the collection zone, the cost per unit of time for using a container, the overall stock of containers available, the available transportation means, the man-hours available, and/or the timeframe constraints for bringing material or containers to the waste treatment facility. - The pre-determined amount is expressed as a volume or a weight of a gaseous, liquid, particulate or solid material; or length or width or height of articles. - The type of materials is one of: the composition of material; the toxic properties, the recyclable properties. - The system can communicate with an auxiliary system controlling the presence of adequate containers to perform the waste collection. - The most appropriate paths inside and outside of the construction/demolition site can be displayed to the drivers of vehicles.

When vehicles are autonomous or partly autonomous, the system can cooperate with the vehicle to automatically or partly automatically control its movements. - The availability and usage of the containers and the amount of material loaded in them can be monitored.

An alert can be triggered if the actual presence or position of the containers or amount of material loaded in the containers deviates significantly from the initial plan.

Messages to appropriate computer devices can be automatically sent.

Advantages of the invention

[0026] The invention is particularly interesting in that it allows a versatile, flexible and adaptable solution to various problems and allow for a reduced amount of ground space to be needed for a waste collection zone on a construction/demolition site as well as a reduced impact on the environment.

Brief description of the drawings

[0027] Some examples of embodiments of the present invention will be clearer in view of the appending figures, in which:

[0028] Figure 1 shows a diagram of a method according to the invention;

[0029] Figure 2 shows a system according to the invention.

Description of an embodiment

[0030] Figure 1 shows a synthetic diagram illustrating the method according to the invention.

[0031] A pool or catalogue 2 of containers is defined and their data is gathered in a database 2. Each container can be characterized by its capacity, dimensions, footprint, etc. Any other relevant information or restriction of use of the container can be included in the database.

[0032] A digital model 4 or any other similar type of planning is defined for scheduling the operations of a construction or demolition site and it can include the detailed description of the operations, such as the inputs/outputs and the actions that must be made. From the definition of the schedule of construction or demolition, a step of estimation of the “production” of waste at each moment in time during the process of construction/demolition can be made. These estimations 6 can for instance take the form of a series of curves as a function of time, for each material. For example, a series of curves of weight as a function of time for each type of material can be drawn. Of course, each type of material can be measured with the most appropriate unit.

[0033] The data 3 extracted from the database 2 and the pre-determined amount of waste material 7 extracted from the estimations 6 can be the basis to form the inputs of a computer-implemented management system 8, together with the navigation system or cartography input 5 allowing the calculation of the distance of the paths travelled by the second transportation means between the collection zone (24, see also figure 2) and the waste treatment facility (32, see figure 2).

[0034] The first purpose of the system 8 is to establish a calculation of the area on the ground that is required to host the containers that are necessary to the evacuation of the waste material during the process of construction/demolition. Indeed, at a construction/demolition site, an area is dedicated to the waste collection. One aim of the system is to establish a choice of containers for each type of waste material which is such that the area of the collection zone will be as small as possible. The second purpose of the system 8 is the calculation of the distance travelled by transportation means to evacuate the containers to a waste treatment facility, remote from the construction/demolition site.

[0035] The system 8 can use any type of solver technique for a multi-objective combinatorial optimization.

[0036] In this particular example, the system 8 calculates for each possible combination of containers allocated to each particular type of waste material, the required area of the collection zone, at a given point in time, and the distance that must be travelled for transporting the containers to the waste treatment facility.

[0037] The system can optionally take into account further external constraints 9, such as the availability of trucks, the restriction of travel at certain moments in time, etc.

[0038] As a result of the calculation, the system 8 can output the various possible optimal selections 10a, 10b, 10c.

[0039] According to the invention, at least three type of optimal selections can be given by the system 8. Selection 10a can be the selection of containers which minimises the overall distance travelled by the secondtransportation means within a certain limit for the area for the collection zone (= sum of footprints of the containers needed at a particular moment in time). Selection 10b can be the selection of containers which minimises the sum of footprints of the containers within a certain limit for the overall distance travelled by the second transportation means. Selection 10c can be the default selection minimising a weighted sum of both criteria.

[0040] Optionally, there may be several solutions 12 which lead to either a minimal area or a minimal distance travelled. The user can be prompted to choose one of these solutions. He may (or may have) pre-set a relative preference (for example in %) for one of the two criteria. The output 12 contains to that end the results of the calculation of area and distance travelled, so that the selection 14 among all suggested combinations 12 can be carried out based on the results calculated by the system 8.

[0041] Optionally, when several solutions 12 are given, an automatic (such as selecting a solution closest to the middle of the ranges determined by the solutions 12) or a manual choice can thus be performed.

[0042] The method continues by step 16 of performing the construction/demolition process using the containers that have been (automatically) chosen for each respective type of material.

[0043] Optionally, a feedback loop can be applied to continuously or sequentially update the choice of containers. This loop is based on the actual situation 18 at a given point in time and it can feed the system 8 with an input 19 which complement or replaces input 3 or 7.

[0044] In practice, this feedback loop allows to integrate the uncertainties of randomly occurring events into the system. If the construction is stopped or rather is in advance on schedule, the optimal choice of containers may be impacted and thanks to this feedback, the optimal conditions are maintained irrespective of such events. The feedback loop can be fed with information based on sensors, such as sensors detecting the presence or the amount of material loaded in each container. An update of the BIM or of the schedule of the construction process 4 can also feed the feedback loop. The actual state of these features is noted 2’, 4’ and 6’on figure 1.

[0045] Figure 2 depicts a system according to the invention. The system 20 comprises a construction or demolition site 22. Nearby the construction or demolition site 22 is arranged a collection zone 24 having an area on the ground 25 for receiving waste containers 26. Each waste container 26 has a respective footprint 27 on the ground. First transportation means 28 are adapted to transport waste from the construction/demolition site 22 to the waste containers 26. These first transportation means 28 can typically be forklifts, cranes, trucks, hand-held tools, or wearable tools (e.g. exoskeletons for construction workers).

[0046] The system is also provided with second transportation means 30 which handle the containers 26. These second transportation means 30 can be trucks, drones, ships. They can be partly or totally autonomous vehicles.

[0047] The second transportation means 30 transport the containers 26 to a waste treatment facility 32. To that end, they travel a definite distance 34 and produce a corresponding amount of pollution.

[0048] First transportation means 26 may also transport waste directly from the construction/demolition site to the waste treatment facility 32, if needed. This may be the case for particularly dangerous material or big material which cannot enter a container, etc.

[0049] The system is equipped with a computer-implemented system (8 on figure 1) for determining the choice of containers to be allocated to each type of waste material so that the required area 25 of the collection zone 24 and the total distance 34 travelled by the entirety of the second transportation means 30 is optimized.

_ EEE

Claims

1. Method for the management of a container handling system, the system comprising: - à plurality of containers (26), preferably waste containers, waste bins, skips, boxes, bags, or barrels, at least two of which having different footprints (27); - à collection zone (24) used for the gathering of at least some of the containers (26); - a source (22) remote from the collection zone (24) and generating a pre- determined amount (7) of waste material of one or more types as a function of time, the source (22) being a construction/demolition site or part of a construction/demolition site: - at least one waste treatment facility (32), remote from the collection zone (24); - first transportation means (28) for transporting waste to the containers (26) or to the waste treatment facility (32); - second transportation means (30) for transporting the containers (26) from/to the collection zone (24); the first and second transportation means (28, 30) moving along paths which define respective distances (34) between the collection zone (24) and the source (22) or between the waste treatment facility (32) and the collection zone (24); the method comprising a step (6) of determination of the amount and type of material (7) generated by the source (22) and a step of allocation (10, 12, 14), by a computer-implemented management system (8), of at least one of the containers (26) to each material, the allocation being made such that one or several container(s) (26) of a given type may be allocated to none, to one or to more than one types of material; and the allocation is performed according to an optimisation process that performs an optimal selection of containers (26), which can be of different types, which optimization aims at minimizing the following two performance criteria:

| 18/24 LU100980 - the sum of footprints (27) of the containers (26) to be stored at any point in time in the collection zone (24) to receive the predetermined amount of waste; - the overall distance (34) travelled by the second transportation means between the collection zone (24) and the waste treatment facility (32) “for gathering the entirety of the amount of waste: | the management system generating an output comprising: - an optimal selection (10a) of containers (26) minimising the overall distance (34) while the sum of footprints (27) remains below a predetermined threshold, if such a selection exists; or - an optimal selection (10b) of containers (26) minimising the sum of the footprints (27) while the overall distance (34) remains below a predetermined threshold, if such a selection exists; or - a default optimal selection (10c) of containers (26) minimising a given weighted sum of both above-mentioned criteria; or - a set of selections (12) of containers (26) which consists in trade-offs between both criteria in accordance with pre-set weights or pre-set acceptable ranges allowed for the criteria, the output consisting in this case in the selections of containers (26) together with the values of the above-mentioned criteria obtained from such selections.

2. Method according to claim 1, characterized by a further step (16) of performing the collection of waste in accordance with said optimal selection (10a) minimising the distance, or in accordance with said optimal selection (10b) minimising the sum of footprints if an optimal selection (10a) minimising the distance does not exist, or in accordance with said default optimal selection (10c) if both selections (10a, 10b) minimising distance and sum of footprints do not exist, or optionally: - if so decided by a user, the step (16) can perform the collection of waste in accordance with a selection (14) of containers (26) chosen by a user amongst the set of selections (12) of containers (26).

3. Method according to claim 1 or 2, characterized in that the pre-determined amount of material is generated by a digital model (4) integrating aschedule of operations to be performed on the construction/demolition site and/or a building information model (4).

4. Method according to any of the previous claims, characterized in that the pre-determined amount of material (7, 19) is sequentially updated in | accordance with the detected amount of waste material already in the containers (26) or already sent to the waste treatment facility (32), or in accordance with information sent by the digital model (4), and the optimized selection of containers (26) is recalculated according to this update.

5. Method according to any of the previous claims, characterized in that the pre-determined amount (7) of waste is expressed as a range of values for each type of material and for a predetermined time frame.

6. Method according to any of the previous claims, characterized in that the amount of waste (7) varies as a function of time and the optimization is made for a given timeframe.

7. Method according to any of the previous claims, characterized in that the containers (26) have a capacity of between 1 and 30 m3.

8. Method according to any of the previous claims, characterized in that the transportation means (28, 30) are autonomous vehicles, such as trucks, airborne vehicles or waterborne vehicles.

9. Method according to any of the previous claims, characterized in that the computer-implemented management system (8) monitors and/or controls the movement of the autonomous transportation means.

10. Method according to any of the previous claims, characterized in that at least thirty of the containers (26) have a respective footprint (27) distinct from each other.

11. Method according to any of the previous claims, characterized in that the optimization process is at least partially performed by brute force computation.

12. Method according to any of the previous claims, characterized in that the optimization process is at least partially performed through heuristicprocesses or known methods from numerical optimization, in particular methods from Mixed-integer or combinatorial optimization such as branch- and-bound type methods.

13. Method according to any of the previous claims, characterized in that the optimization process also attempts to minimise the total number of containers (26) and/or number of transportation means (28, 30) and/or number of trips required for transporting the entirety of the pre-determined material from the source (22) to the collection zone (24) and/or from the collection zone (24) to the waste treatment facility (32).

14. Method according to any of the previous claims, characterized in that the optimization process takes also into consideration the lower and upper values of the range of material, in order to perform an optimization returning at least one optimal selection of containers (26) that is optimal over the whole range of expected values for each said material.

15. Method according to any of the previous claims, characterized in that the optimization process takes also into consideration further constraints forming further criteria for the optimization process, such as: the cost per hour of immobilisation of a container (26) in the collection zone (24), the cost per unit of time for using a container (26), the overall stock of containers (26) available, the available transportation means (28, 30), the man-hours available, and/or the timeframe constraints for bringing material or containers (26) to the waste treatment facility (32).

16. Method according to any of the previous claims, characterized in that the pre-determined amount (7) is expressed as a volume or a weight of a gaseous, liquid, particulate or solid material; or length or width or height of articles.

17. Method according to any of the previous claims, characterized in that the type of materials is one of: the composition of material; the toxic properties, the recyclable properties.

18. Container handling system (20) comprising:

- a plurality of containers (26), preferably waste containers, waste bins, skips, boxes, bags, or barrels, at least two of which having different footprints (27); - a collection zone (24) used for the gathering of at least some of the containers (26); - a source (22) remote from the collection zone (24) and generating a pre- | determined amount (7) of waste material of one or more types as a function of time, the source (22) being a construction/demolition site or part of a construction/demolition site; - at least one waste treatment facility (32), remote from the collection zone (24); - first transportation means (28) for transporting waste to the containers (26) or to the waste treatment facility (32); - second transportation means (30) for transporting the containers (26) from/to the collection zone (24); the first and second transportation means (28, 30) moving along paths which define respective distances (34) between the collection zone (24) and the source (22) or between the waste treatment facility (32) and the collection zone (24); - a computer-implemented management system (8) configured for allocating at least one of the containers (26) to each material, the allocation being made such that one or several container(s) of a given type may be allocated to none, to one or to more than one types of material; and the allocation is performed according to an optimisation process that performs an optimal selection of containers (26), which can be of different types, which optimization aims at minimizing the following two performance criteria: - the sum of footprints (27) of the containers (26) to be stored at any point in time in the collection zone (24) to receive the predetermined amount (7) of waste;

| 22/24 LU100980 - the overall distance (34) travelled by the second transportation means between the collection zone (24) and the waste treatment facility (32) for gathering the entirety of the amount of waste; the management system (8) generating an output comprising: - an optimal selection (10a) of containers (26) minimising the overall distance (34) while the sum of footprints (27) remains below a predetermined threshold, if such a selection exists; or - an optimal selection (10b) of containers (26) minimising the sum of the footprints (27) while the overall distance (34) remains below a predetermined threshold, if such a selection exists; or - a default optimal selection (10c) of containers (26) minimising a given weighted sum of both above-mentioned criteria; or - a set of selections of containers (26) which consists in trade-offs between both criteria in accordance with pre-set weights or pre-set acceptable ranges allowed for the criteria, the output consisting in this case in the selections of containers (26) together with the values of the above-mentioned criteria obtained from such selections.

19. System according to claim 18, characterized in that the management system (8) is adapted to perform a step (16) of performing the collection of waste in accordance with said optimal selection (10a) minimising the distance, or in accordance with said optimal selection (10b) minimising the sum of footprints if an optimal selection (10a) minimising the distance does not exist, or in accordance with said default optimal selection (10c) if both selections (10a, 10b) minimising distance and sum of footprints do not exist.

20. System according to claim 18 or 19, characterized in that it further comprises a computer-implemented digital model (4) for the pre- determination of the amount of material, the digital model integrating a schedule of operations to be performed on the construction/demolition site and/or a building information model.

21. Method according to any of the claims 18 to 20, characterized in that the pre-determined amount of material (7, 19) is sequentially updated in accordance with the detected amount of waste (19) material already in the containers (26) or already sent to the waste treatment facility (32), or in accordance with information sent by the digital model, and the optimized selection of containers (26) is recalculated according to this update.

| 22. System according to any of the claims 18 to 21, characterized in that the | pre-determined amount of waste (7) is expressed as a range of values for each type of material and for a predetermined time frame.

23. System according to any of the claims 18 to 22, characterized in that the amount of waste (7) varies as a function of time and the optimization is made for a given timeframe.

24. System according to any of the claims 18 to 23, characterized in that the containers (26) have a capacity of between 1 and 30 m3.

25. System according to any of the claims 18 to 24, characterized in that the transportation means (28, 30) are autonomous vehicles, such as trucks, airborne vehicles or waterborne vehicles.

26. System according to any of the claims 18 to 25, characterized in that the computer-implemented management system (8) monitors and/or controls the movement of the autonomous transportation means.

27. System according to any of the claims 18 to 26, characterized in that at least thirty of the containers (26) have a respective footprint (27) distinct from each other.

28. System according to any of the claims 18 to 27, characterized in that the optimization process is at least partially performed by brute force computation.

29. System according to any of the claims 18 to 28, characterized in that the optimization process is at least partially performed through heuristic processes or known methods from numerical optimization, in particular methods from Mixed-integer or combinatorial optimization such as branch- and-bound type methods.

30. System according to any of the claims 18 to 29, characterized in that the optimization process also attempts to minimise the total number of containers (26) and/or number of transportation means (28, 30) and/or number of trips required for transporting the entirety of the pre-determined material from the source (22) to the collection zone (24) and/or from the collection zone (24) to the waste treatment facility (32).

31. System according to any of the claims 18 to 30, characterized in that the optimization process takes also into consideration the lower and upper values of the range of material (7), in order to perform an optimization returning at least one optimal selection of containers (26) that is optimal over the whole range of expected values for each said material.

32. System according to any of the claims 18 to 31, characterized in that the optimization process takes also into consideration further constraints forming further criteria for the optimization process, such as: the cost per hour of immobilisation of a container (26) in the collection zone (24), the cost per unit of time for using a container (26), the overall stock of containers (26) available, the available transportation means, the man- hours available, and/or the timeframe constraints for bringing material or containers (26) to the waste treatment facility (32).

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