Abstract:
The invention relates to a planning system and method for operating one or more road milling machines. In that context, material properties of a road are captured and are geographically associated with one or more roads or road segments. Based on the material properties, an expected milling output of a road milling machine is ascertained, in the context of carrying out milling tasks on the road, or an expected wear on the milling tools. An optimized sequence of milling tasks to be carried out is created on the basis of those data. Accordingly, the invention may enable optimized deployment of the one or more road milling machines and of resources necessary for carrying out the road milling tasks. Aspects of the planning system may be remotely implemented for centralized application with respect to each of the road milling machines, or locally implemented for individual road milling machines.

Description:
[0001]    A portion of the disclosure of this patent document contains material that is subject to copyright protection. The copyright owner has no objection to the reproduction of the patent document or the patent disclosure, as it appears in the U.S. Patent and Trademark Office patent file or records, but otherwise reserves all copyright rights whatsoever. 
       CROSS-REFERENCES TO RELATED APPLICATIONS 
       [0002]    This application claims benefit of German patent application 10 2016 102 568.2, filed Feb. 15, 2016, and which is hereby incorporated by reference. 
       BACKGROUND OF THE INVENTION 
       [0003]    Road milling machines with which one, several, or all layers of a road can be removed by milling, are used nowadays to remove traffic surfaces, for example roads, road segments, or parking lots. The milling output achievable with a respective road milling machine, for example the milling area achievable per unit time or the milling volume achievable per unit time, depends greatly on the material properties of the traffic surface to be processed. The wear on the milling tools is also influenced directly by the material properties of the road or road segment. These relationships make it difficult to plan machine deployment for pending road milling tasks. The result can be that more resources than necessary, in terms of time, machinery, or materials, are provided for a road milling task, leading to elevated costs. Insufficient resources can likewise be allocated, which can result in delays. This becomes negatively evident in particular in a context of successively scheduled milling tasks, and can result in large consequential losses, for example if subsequent processing steps cannot be executed or are executed late. 
         [0004]    The document DE 10 2013 112 972 A1 discloses a method for wear prognosis for an earth working machine, in particular a road milling machine. Here the current wear state of a bit or a bit holder is captured, and a residual wear capacity is ascertained from the current wear state. From that capacity, the remaining working output until the tools have reached their wear limit, for example in the form of a mass still millable, or a milling volume, or a remaining work time, can be ascertained. The material properties of the substrate to be processed can also be considered in determining the remaining working output. Those properties can be deduced, for example, by taking samples or on the basis of machine parameters of the earth working machine which are established in the context of milling. 
         [0005]    US 2015/0197253 A1 discloses a system that, in the context of processing of a ground surface, for example a road, with an earth working machine, ascertains the quality of a working step in positionally resolved fashion and displays it graphically. The quality of a processed road segment can be ascertained and evaluated using suitable sensors on the road construction machine and by comparison with specified values. The positionally resolved graphic depiction allows an operator of the road construction machine to rework individual road segments in targeted fashion. Ground irregularities caused by “jumps” of the earth working machine can represent, for example, a quality feature. 
       BRIEF SUMMARY OF THE INVENTION 
       [0006]    An object of the invention is to furnish a method, a control device, and a computer program product that enable optimized deployment of road milling machines and of the resources necessary for carrying out road milling tasks. 
         [0007]    An object of the invention is achieved by a method for operating one or more road milling machines, encompassing at least the following steps:
       determining and/or reading in material properties of roads and/or road segments, and/or characteristic values correlating with the material properties;   associating the material properties and/or the characteristic values with respectively pertinent road designations and/or designations of road segments and/or geographic coordinates;   specifying at least two roads and/or road segments to be processed by milling;   ascertaining at least one expected milling output of the road milling machine for the roads and/or road segments to be processed, based on the material properties and/or characteristic values determined for the roads or road segments;   ascertaining and displaying a sequence, optimized at least with regard to milling output, of the road milling tasks that are to be carried out.       
 
         [0013]    For purposes of the invention, the terms “road” and “road segment” encompass any forms of paved traffic routes and traffic surfaces, i.e. including parking lots, sidewalks, bicycle paths, or the like. 
         [0014]    With suitably selected machine parameters of the road milling machine, the achievable milling output of a road milling machine is defined substantially by the material properties of the road or road segment to be removed. If the material properties of the road or road segment are known, or if the characteristic values that correlate with those material properties are known, it is thus possible to arrive at a forecast of the achievable milling output. This forecast is valid for suitably selected machine parameters. If the milling output is known, exact planning of pending milling tasks can be accomplished. In particular, the sequence of different milling segments within a construction site, or the sequence of different road milling tasks at different construction sites, can be optimally specified. Optimization preferably can be accomplished with regard to a required working time and/or the required resources. It is furthermore possible to mutually coordinate the deployment of multiple road milling machines. 
         [0015]    The method thus enables optimum operation of one or more road milling machines with regard to their working output and the resources needed in order to operate them. Total costs, in particular for carrying out several successive milling tasks, can thereby be appreciably reduced. 
         [0016]    According to one embodiment of the invention, provision can be made that a working time span and/or an operating supplies consumption and/or a wear on at least one tool of the road milling machine and/or a quantity of required consumable parts and/or a quantity of required operating supplies and/or a quantity of required operating auxiliaries for carrying out a specified road milling task is determined on the basis of the material properties and/or characteristic values associated with a road or road segment to be processed, and is displayed, and/or is taken into consideration in ascertaining the sequence of the road milling tasks to be carried out. In particular, given a known working time span, two or more milling tasks to be carried out can be optimally coordinated with one another in terms of their execution. In addition, simultaneous deployment of several road milling machines can be coordinated. Cost-intensive road milling machine downtimes and waiting times can thereby be very largely avoided. If the wear on the milling tools is known, pending milling tasks can be scheduled in such a way that, for example, necessary tool changes occur at road milling machine downtimes that are necessary in any case, for example after completion of a milling task. 
         [0017]    Regardless of the method selected for determining the characteristic values correlating with the material properties, provision can be made that the material properties for a road or road segment are determined from the characteristic values. Based on the material properties, for any road milling machine it is then possible to make a forecast, matched to its properties, for the milling output, the wear on the milling tools, and the required consumption of material and resources. 
         [0018]    The milling output of a road milling machine, the wear on its milling tools, and the required material resources and consumable resources can be forecast with sufficient accuracy, for example, if an abrasiveness and/or a hardness and/or a material type and/or a material composition and/or a temperature and/or a layer structure of the road or road segment is determined as a material property. 
         [0019]    The milling output of the road milling machine, the wear on its milling tools, and the required material resources and consumable resources can furthermore be accurately forecast by the fact that at least one machine parameter of a road milling machine which is obtained for execution of a milling task to be planned is determined as a characteristic value correlating with the material properties. 
         [0020]    For determination of the material properties provision can be made, for example, that during a first milling process that is carried out within a working sector to be processed, a milling depth and/or an advance of the road milling machine and/or a milling drum rotation speed of a milling drum of the road milling machine and/or a torque transferred to the milling drum and/or a drive power transferred to the milling drum or an operating supplies consumption is determined as a machine parameter. For a specified milling depth, a specified advance, and a specified milling drum rotation speed, for example, a necessary torque to be transferred to the milling drum will result as a function of the existing material properties of the road or road segment to be milled. A higher torque will be required for a harder road than for a softer road. The material properties of the road or road segment can thus be inferred based on the machine parameters or combination of those machine parameters that are set and that result. The machine parameters or the material properties derived therefrom can be ascertained, for example, during a first milling process on a road or road segment. Based on the material properties, or the machine parameters constituting characteristic values correlating with the material properties, that are thereby obtained, a forecast can then be created for the milling output, the wear on the milling tools, or the required utilization of materials and resources for a further milling deployment in the working sector within which the material properties can be assumed to be identical or similar to those in the segment already milled. For example, in the case of a multi-lane roadway it is usual firstly to mill off one lane and to process the additional lanes later. It can be assumed, for the lanes yet to be processed, that the material properties are the same as those ascertained based on the machine parameters upon milling of the lane already processed. The previously ascertained machine parameters, and the material properties derived therefrom, can therefore be used for the process of planning work on the remaining lanes. 
         [0021]    The accuracy of the determination of material properties from the machine parameters of a road milling machine in the context of a previously executed milling procedure in the work sector to be planned can be improved by taking into consideration, in determining the material properties from the machine parameters, a wear that has occurred on at least one tool of the road milling machine in the context of milling a specific area. By evaluating the machine parameters and the wear together, it is possible to infer with high accuracy the material properties of the substrate being processed. 
         [0022]    According to a variant embodiment of the invention, provision can be made that position data of a road milling machine are captured and are associated with the determined material properties and/or characteristic values. For example, during a milling process on a road segment, the material properties or the characteristic values can be associated unequivocally and, for example, automatically with the pertinent position data. The material properties or characteristic values thereby obtained can then be used for further construction site planning in the respective working sector. During a planning process, the pertinent material properties and characteristic values for the road or road segment on which the road milling machine has already worked can be retrieved on the basis of the position data of the road milling machine. The forecast of the milling output, wear, or material and resource consumption can then be made based respectively on those material properties or characteristic values. A procedure of this kind is advantageous, for example, in the context of a decentrally arranged planning system, in which planning of a milling task to be carried out is accomplished directly on site at at least one of the road milling machines that is provided. 
         [0023]    It is furthermore conceivable for the material properties and/or the characteristic values correlating with the material properties to be determined from the process of installing the road or road segment. Based on the machines, materials, and process parameters used when the road or road segment was installed, the material properties required for a subsequent milling process can be ascertained and stored in positionally resolved fashion or for a specified working sector. Those material properties, or ones derived therefrom, can then be returned to when the road or road segment is subsequently removed by milling. It is particularly advantageous in this context that a separate determination of the material properties of a road or road segment to be processed does not need to be made prior to planning of a milling task that is to be carried out. 
         [0024]    In accordance with a possible variant embodiment of the invention, provision can be made that measured data ascertained with a measurement system are determined as characteristic values correlating with the material properties. The measurement system can determine, for example, the hardness of a road surface or the layer structure of a road. It is likewise conceivable to carry out suitable measurements on drill cores of previously executed test holes. The measured data can then be associated with the pertinent road, the pertinent road segment, or a pertinent sector. The measured data can directly represent the necessary material properties, or the material properties can be ascertained from the measured data. 
         [0025]    In accordance with another variant embodiment of the invention, provision can be made that transport times of the road milling machine between the roads and/or road segments to be processed, and/or maintenance intervals of the road milling machine, are taken into consideration in the specification of the sequence of road milling tasks. This measure allows downtimes of the road milling machine to be avoided or at least reduced, with the result that total costs for the milling tasks to be carried out can be lowered. 
         [0026]    Optimized construction site planning can be achieved by the fact that a milled area and/or a milled volume and/or a milled mass and/or a milled distance, referred in each case to a time unit, is determined as a milling output. The necessary work quantity, for example in the form of an area to be milled, a volume to be milled, a mass to be milled, or a distance to be milled, is known in the context of planning a milling project. Once the milling output is ascertained based on the material properties of the road or road segment, then, for example, the time span for carrying out the milling project can be determined based on the work quantity and the milling output. Necessary downtimes of the road milling machine can be taken into consideration in this context. For a known wear on the milling tools, e.g. referred to a work quantity or a deployment time, it is possible, for example, to forecast and correspondingly take into consideration necessary road milling machine downtimes for replacement of the milling tools. The sequence of milling tasks to be carried out in succession, including using several road milling machines, can thereby be optimally coordinated. It is also conceivable to capture and store the work quantity for processing a road or road segment in the context of the method, so that it can be returned to during the planning phase. For example, the work quantity can already be captured and stored during installation of a road or road segment. 
         [0027]    An object of the invention is furthermore achieved by a planning system for coordinating road milling tasks for one or more road milling machines, the planning system comprising a memory networked with input and output units associated with the one or more road milling machines, and a medium having a computer program product stored thereon, the program product executable by a computer to carry out the above-described method. 
         [0028]    In an embodiment, the computer program product can be loaded directly into the internal memory of a digital computer. 
         [0029]    In an embodiment, the computer program product can be stored on a medium that is insertable into a computer. 
         [0030]    In an embodiment, the computer can be integrated into a control device or can be part of the control device. 
     
    
     
       BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS 
         [0031]      FIG. 1  is a schematic side view depicting a road milling machine; 
           [0032]      FIG. 2  is a simplified schematic depiction of an example of a structure of a road; 
           [0033]      FIG. 3  is a simplified block depiction of a planning system for planning road milling tasks; 
           [0034]      FIG. 4  is a block depiction of individual method steps during a planning phase; and 
           [0035]      FIG. 5  is a block depiction of individual method steps during a data capture phase. 
       
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
       [0036]      FIG. 1  is a schematic side view depicting a road milling machine  10 . A machine frame  12  is carried, vertically adjustably via four lifting columns  16 . 1 ,  16 . 2 , by propelling units  11 . 1 ,  11 . 2 , for example tracked propelling units. Road milling machine  10  can be operated from a control stand  13  via a control system  17  arranged in control stand  13 . A milling drum  15  (arranged in concealed fashion and depicted with dashed lines) is rotatably mounted in a milling drum box that is likewise arranged in concealed fashion. A conveying device  14  serves to transport away the milled material. 
         [0037]    During use, road milling machine  10  is moved, at an advance speed entered via control system  17 , over the substrate to be processed. In that context, milling tools (not depicted) arranged on the rotating milling drum  15  remove road  20  whose structure is shown in  FIG. 2 . The milling tools are configured as a rule as bits, preferably round-shank bits, that are installed replaceably in bit holders. Bit holder changing systems, in which the bit holders are replaceably mounted in base parts, are known and are usable in the context of the invention. The base parts are mounted on the surface of the milling drum, for example welded thereonto. The arrangement of the milling tools and bit holders can be such that one or more cutting helices are produced on the surface of the milling drum. The cutting helices result in a more sequential cutting engagement of the milling tools. The cutting helices can furthermore also perform a clearing and loading function, the removed milled material being transported along the surface of milling drum  15  to an ejection position. Milling drum  15  is driven by a motor via a drive unit. The vertical position and rotation speed of milling drum  15  can be adjusted from control system  17 . The milling depth is adjusted by way of the vertical position of milling drum  15 . The vertical position of milling drum  15  relative to the surface to be processed can be adjusted relative to the machine frame via the vertically adjustable lifting columns  16 . 1 ,  16 . 2  or via a separate vertical adjustment system, depending on the type of machine. The advance speed and the milling depth ultimately determine the working output of road milling machine  10 , i.e. for example a distance or area or mass removed per unit time, or a removed volume. 
         [0038]    The working output achievable with a road milling machine  10 , and the wear on the milling tools, depend greatly on the material properties of road  20  that is to be removed, for example on its hardness or abrasiveness. This complicates construction site planning with regard to the achievable milling output and thus the required working time, and the expected wear on the milling tools. Mutual coordination of milling tasks to be carried out successively is thus insufficient, which results in delays or in undesired downtimes of road milling machine  10 . The quantity of materials required for the operation of road milling machine  10 , for example consumable parts, operating supplies, or operating auxiliaries, cannot be forecast with sufficient accuracy. In the one case this can cause too much material to be delivered to a construction site, which is accompanied by correspondingly elevated costs. In the other case, undesired delays can occur due to insufficient availability of materials. 
         [0039]      FIG. 2  is a simplified schematic depiction of an example of a structure of a road  20 . Starting from a road bed  26 , a freeze protection layer  25  and a gravel base layer  24  are provided. Built thereon are an asphalt base layer  23 , a binder layer  22 , and a surface course  21 , which constitutes road surface  20 . 1 . Depending on the milling work to be performed, one or more of these layers are removed with the aid of road milling machine  10 . 
         [0040]    The material properties of road  20  which are relevant in terms of milling result from the materials used, the conditions and process parameters upon installation of road  20 , and the thicknesses of the individual layers. The material properties can also depend on prevailing ambient conditions, for example the ambient temperature. Relevant material properties can be an abrasiveness or hardness of road  20 . These are determined by the material type, a material composition, a temperature, and/or a layer structure of road  20 . 
         [0041]    The material properties of a road structure are usually consistent over a large region. Asphalt mixtures that are as uniform as possible in quality are used, for example, upon installation of a new roadway surface. Installation is preferably accomplished in one working step, as is obligatorily necessary, for example, in the case of open-pore asphalt (OPA). A road structure thus exhibits for the most part relatively constant material properties within specific sectors, for example within an expressway segment or within a region defined by geographic coordinates. It is thus possible to associate material properties with a location or with a spatially delimited sector. The location or sector can preferably be defined by a road designation, a designation of a road segment, or by geographic coordinates. If the material properties for a road  20  are known, then according to the present invention it is possible to create, for future milling tasks on road  20 , a prognosis of the working outputs of a road milling machine  10  and/or the wear on the milling tools that can be expected. These values can be taken into consideration in planning a future construction site or sites. It is thereby possible to ascertain, from the expected working output, the time required for carrying out a milling task. When the wear on the milling tools is known, the spare parts necessary for them can be determined. The operating supplies and auxiliaries that are required can likewise be ascertained. With knowledge of this data, according to the present invention a sequence of different milling tasks that are to be carried out can be ascertained and specified in optimized fashion so as to result in a minimum total outlay in terms of time and materials. Transport times for the road milling machine between various construction sites are preferably also taken into consideration. Required downtimes of road milling machine  10 , for example for maintenance work that needs to be performed, can advantageously also be incorporated into construction site planning. Optimized deployment planning for one or more road milling machines  10  is thereby made possible. 
         [0042]    Thanks to deployment planning optimized in this fashion, total costs for the milling tasks to be carried out can be appreciably reduced due to reduced downtimes of road milling machine or machines  10  as well as decreased material, storage, and transport costs. 
         [0043]      FIG. 3  is a simplified block depiction of a possible variant embodiment of a planning system  30  for planning road milling tasks. An electronic memory  31 , and a computation unit  32  connected to memory  31 , are associated with planning system  30 . An input unit  34  and an output unit  33  are also connected to planning system  30 . Planning system  30  comprises an interface  30 . 1  for transferring, for example, characteristic values  40  correlating with the material properties of a road  20 . Interface  30 . 1  is designed in the present case as a radio interface. It can also be embodied, however, as a wire-based interface, for example in the form of a USB interface; or different types of interface  30 . 1  can be provided. Installation data  41  from the installation process of a road  20 , measured and experimental data  42  for ascertaining material properties of a road  20 , and/or milling data  43  of a road milling machine  10  in the context of removal of a road  20 , can be read into planning system  30  via interface  30 . 1  as characteristic values  40  correlating with the material properties. Position data  80  can also be transferred, or material properties of a road  20  can be transferred directly, via interface  30 . 1  to planning system  30 . Further data can preferably also be transferred via interface  30 . 1  to planning system  30 , or outputted from planning system  30 . Alternatively thereto, the aforesaid data or portions of the data (e.g. material properties, characteristic values  40 , position data  80 ) can also be inputted via input unit  34  into planning system  30  or outputted via output unit  33 . The data are stored in electronic memory  31  and managed, for example, via a database system. The pertinent position values  80  are associated with the material properties and/or characteristic values  40 . Position values  80  are preferably indicated in the form of spatially delimited geographic coordinates or road designations or designations of road segments, i.e. as defined and spatially delimited working sectors. The material properties, or the characteristic values correlating therewith, can be saved simultaneously with, or with a time offset from, the pertinent position data  80 . 
         [0044]    Computation unit  32  can be configured to ascertain characteristic values  40 , or the material properties directly, from installation data  41 , measured data  42 , and/or milling data  43 . 
         [0045]    Preferably the material properties of a road  20  are already captured as installation data ( 41 ) in the process of installing the road. The layer structure and the material composition are known in the context of the installation process, and the material properties can be deduced therefrom. 
         [0046]    Road milling machines  10  can remove only a portion of a road surface, for example a single lane on an expressway. In some circumstances they also do not mill the entire length of the area to be processed in one working step. It may therefore happen that at a first point in time firstly a portion of an existing roadway is removed, and work at that site is not continued until a later point in time. The material properties of road  20  can be manually or automatically ascertained during the milling tasks carried out at the first point in time. For example, the material properties can be derived from milling data  43  ascertained during the milling process, for example machine parameters  74  of road milling machine  10 . The material properties thereby ascertained can then be used to plan the remaining milling tasks. The prognosis, for example for the future milling output or expected wear, is made within a limited working sector in which consistent material properties of road  20  or roads  20 , or of the road segments, that are to be milled can be assumed. 
         [0047]    The working sectors can advantageously be defined and retrieved descriptively. A road designation or a designation of a road segment is preferably used for this, for example an expressway designation within a region delimited by a mileage indication. 
         [0048]    During capture of the material properties or of characteristic values  40  correlating therewith, an operator can manually capture the pertinent working sector and store it in planning system  30 . Alternatively thereto, a machine position, for example of a road construction machine upon installation of a road  20  or of a road milling machine  10  upon removal of a road, can be captured together with the material properties or characteristic values  40  obtained in that context. An operator can then define and input a working sector, around the machine position, for which the material properties or characteristic values are relevant. For the installation process, the exact position data of the installed material, and/or the pertinent process parameters, can advantageously be captured and stored in positionally resolved fashion. Here as well, the position data can be captured manually or automatically and transferred to planning system  30 . 
         [0049]    Planning system  30 , or parts of planning system  30 , advantageously are arranged centrally. Planning system  30  can thereby be used by different users and/or for the planning of different construction sites. A centrally arranged planning system  30  is advantageously networked with decentrally provided input and output units  34 ,  33 . From these, planning system  30  can be accessed and the respective data capture (material properties, characteristic values  40 , working sectors) or construction site planning can be carried out. Input and output units  34 ,  33  can be arranged for that purpose, for example, on corresponding road milling machines  10 . It is also possible for only memory  31 , and if applicable a database function, to be arranged centrally, and for computation units  32  as well as input and output units  33 ,  34  to be provided decentrally. The central or partly central arrangement of planning system  30  is advantageous in that the current data inventory exists uniformly for all users of planning system  30 . Alternatively thereto, provision can be made that planning system  30  is arranged decentrally, for example on the respective road milling machines  10 . Advantageously, the decentrally arranged planning systems  30  are networked or networkable with one another, so that the data stored in memory  31  can be exchanged. 
         [0050]    The material properties can be stored directly in memory  31  for the individual working sectors. Alternatively, however, unprocessed data from the installation process, from a measurement process, and/or from a milling process can also be stored. The unprocessed data constitute characteristic values  40  correlating with the material properties. From these values the respective material properties can preferably be determined by computation unit  32  and used for the planning process. Alternatively, however, it is also conceivable for the unprocessed data (characteristic values  40 ) to be used directly for the planning process. For example, machine parameters  74  ascertained during a milling process, or the milling output of a road milling machine  10  produced during a working process, can be stored as characteristic values  40 . Those machine parameters  74  can then be used for a planning process in the same working sector. Advantageously, the material properties therefore do not need to be ascertained from machine parameters  74 . Machine parameters  74  are preferably used for planning processes for road milling machines  10  of the same type as road milling machine  10  with which machine parameters  74  were ascertained. Also conceivable, however, is a transfer to road milling machines  10  of another type; here the differing output data of road milling machines  10  need to be taken into consideration. 
         [0051]    Positional association of the captured material properties or characteristic values  40  can be accomplished automatically upon capture of the data, for example with a GPS system. Alternatively thereto, the captured material properties or characteristic values  40  can also be associated with manually determined working regions. This can occur immediately during capture, or with a separation in time therefrom. For example, it is possible to capture and store the installation data during installation of a road. The data can then be transferred to planning system  30 , for example by data telecommunication or by means of a mobile data medium, and stored in memory  31 . Association of the pertinent working sector can then be carried out subsequently at planning system  30 . 
         [0052]      FIG. 4  is a block depiction, in the form of a flow chart  50 , of one possible embodiment of individual method steps during a planning phase of road milling tasks that are to be carried out. Associated with flow chart  50  are, in sequence, a first block  51 , a second block  52 , and a third block  53 . Third block  53  is connected to a fourth block  54 , a fifth block  55 , a sixth block  56 , and seventh block  57 . 
         [0053]    In first block  51 , a selection of the intended working location is made. This can be done, for example, by inputting a working sector into planning system  30  by means of input unit  34  shown in  FIG. 3 . The working sector can be characterized by spatially delimited geographic coordinates or by a unique designation of a road  20  or road segment. In second block  52 , the material properties for the working sector are requested from memory  31 . Planning system  30  preferably has for that purpose a suitable database for managing the stored data. Based on those material properties, in third block  53  planning system  30  creates, for the working sector specified in first block  51 , a prognosis for the expected working outputs and required materials. In the exemplifying embodiment shown, an expected milling output is outputted for this purpose in fourth block  54 . The milling output can be, for example, a distance or area to be milled per unit time. The milling output can also be indicated by way of a volume to be milled or a mass to be milled. In the exemplifying embodiment shown, an expected wear on the milling tools is also ascertained based on the material properties, and indicated in fifth block  55 . The wear can be indicated, for example, in the form of a wear rate, for example a change in a bit length or bit volume per unit time, or also with reference to a milling work that has been carried out. The latter would be, for example, a change in a bit length or bit volume per milled mass, per milled volume, or per milled distance or area. It is also conceivable to predict the number of tool changes required during the milling task that is to be planned. As a result, advantageously, the necessary spare parts for a construction site can be furnished. An expected working time span for carrying out the milling task is preferably also ascertained, as provided for in sixth block  56 . In accordance with seventh block  57 , provision is advantageously made to predict an operating supplies consumption of road milling machine  10 . With knowledge of these and, as applicable, further expected milling and consumption data, optimized construction site planning can be effected. This relates on the one hand to the furnishing of requisite materials, in particular spare parts, operating supplies, and operating auxiliaries. On the other hand, optimized time-related deployment planning for road milling machine  10  or several road milling machines  10  can be accomplished based on the expected working time span and milling output. This is advantageous in particular when planning successive tasks at several working locations, since it is thereby possible to plan an optimized construction site sequence and to reduce downtimes for road milling machine(s)  10 . 
         [0054]      FIG. 5  is a block depiction of individual method steps during a data capture phase. 
         [0055]    An “installation process data capture” branch  60  represents the ascertaining and storage of material properties during the process of installing a road  20 . A layer structure  61 , mix properties  62 , and compaction data  63  are conveyed to an “installation data capture” block  64 . A temperature  62 . 1  of the mix, as well as mix material properties  62 . 2  of the mix itself or of the components of the mix, are taken into consideration in the indication of mix properties  62 . The composition of the mix is preferably also incorporated in this context. The position data pertinent to the installation data are captured in a “position data capture” block  65 . The data from installation data capture block  64  and position data capture block  65  are delivered to an “association” block  66  and therein respectively to a “material properties” block  66 . 1  and to a “working sector” block  66 . 2 . The data are then directed to memory  31 . 
         [0056]    For data capture during the installation process, layer structure  61 , mix properties  62 , compaction data  63 , and the pertinent position data can be captured from the road construction machine(s) being used, or their operators, and inputted manually into planning system  30  via input unit  34  shown in  FIG. 3 . Alternatively thereto, provision can be made that the data are read directly into planning system  30  from the road construction machines via interface  30 . 1  shown in  FIG. 3 . The position data are furnished for this purpose preferably by a position detection system, for example a GPS, arranged on the road construction machine. It is also conceivable for an operator of the road construction machine to capture and input its current position. The distance covered during installation, and if applicable also the installation width, are captured electronically, with the result that regions having identical material properties can be defined very accurately. Spatially delimited working sectors within which the material properties of road  20  are identical are created from the position data automatically by the planning system or by input via input unit  34 . The relevant material properties of road  20  are ascertained from the installation data of road  20  collected in installation data capture data block  64 , and are associated in association block  66  with the working sectors defined by the position data. The working sectors can be described by limited geographic coordinates or by designations of roads or road segments. The material properties are ascertained from the installation data preferably in computation unit  32  shown in  FIG. 3 . The working sectors and the respectively pertinent material properties are then stored in memory  31 . Alternatively, it is possible for the installation data to be associated with the working sectors and stored in memory  31 . The installation data then constitute characteristic values  40  correlating with the material properties of road  20 . 
         [0057]    In an embodiment, a “milling data capture” branch  70  has the capability of ascertaining the necessary material properties during a milling process. Milling data capture branch  70  encompasses a second position data capture block  71 , a “manual input” block  72 , and a second association block  73  having a second working sector block  73 . 1  and a second material properties block  73 . 2 . Machine parameters  74  of road milling machine  10  are delivered to a “milling parameter capture” block  75  and forwarded to second material properties block  73 . 2 . In the exemplifying embodiment shown, a milling depth  74 . 1 , a wear  74 . 2 , an advance  74 . 3 , an operating supplies consumption  74 . 4 , and a milling drum rotation speed  74 . 5  are provided as machine parameters  74 . Alternatively, further machine parameters  74  influenced by the material properties of road  20  to be milled can be provided, for example a torque transferred to the milling drum; or only some of machine parameters  74  indicated, or an individual machine parameter  74 , can be used. 
         [0058]    In the context of performing a milling task, machine parameters  74  specified by an operator, and those resulting therefrom, of a road milling machine  10  that is being used depend on the material properties of road  20  that is to be milled. With a comparatively hard road  20 , for example, a higher torque transferred to the milling drum will be needed in order to achieve a specified milling drum rotation speed  74 . 5 , at a specified milling depth  74 . 1  and a specified advance  74 . 3 , than with a less hard road  20 . The material properties of the milled road  20  can thus be ascertained in second material properties block  73 . 2  from machine parameters  74  collected in milling parameter capture block  75 . Machine parameters  74  can be transferred directly from road milling machine  10  to planning system  30 . Alternatively thereto, machine parameters  74  can be inputted in manual input block  72 , for example via input unit  34  shown in  FIG. 3 . 
         [0059]    The necessary material properties, or characteristic values  40  correlating therewith, can thus be captured both by data capture during the process of installing a road  20  and by data capture during initial milling work on road  20 , and associated with pertinent working sectors. These data can be stored in memory  31  and used for the subsequent planning process. 
         [0060]    It is also conceivable to capture the necessary material properties via one or more measurements on road  20  or on the road segment. In all cases, the material properties and the pertinent position data can be manually or automatically captured and manually or automatically transferred into planning system  30 . It is also possible for position data to be captured automatically, and for an operator to input manually that spatially delimited region around the captured position data for which the material properties or characteristic values are relevant. 
         [0061]    Planning system  30 , and the underlying planning method, enable an accurate prognosis of future road milling tasks at least in terms of the expected milling output and expected wear. The prognosis preferably proceeds from correctly adjusted machine parameters  74  during the milling procedure. Knowledge of this data makes possible optimized work organization and construction site fulfillment. Planning system  30  can be centrally arranged or can be provided locally on a road milling machine  10 .