Abstract:
The invention proposes an autonomous mobile robotic device in the form of an integrated machine for producing beverages or liquid comestibles.

Description:
FIELD OF THE INVENTION  
     This application is a 371 filing of International Patent Application PCT/EP2008/050478 filed Jan. 17, 2008. 
     The framework of the present invention is the production of beverages or liquid comestibles on the basis of a liquid such as e.g. water or milk and ingredients. 
     SUMMARY OF THE INVENTION 
     It is thereby the object of the present invention to propose a technology offering the production of such products in an appealing manner. 
     The invention proposes a fully autonomous and preferably completely embedded mobile coffee machine with one or more user interfaces. 
     The invention proposes an autonomous mobile robotic device, comprising an integrated machine for producing beverages or liquid comestibles. 
     The device can comprise a controller for the production machine, the controller being connected to a wireless interface designed for receiving wirelessly transmitted signals able to set the operation of the production machine. 
     The device can comprise a controller for the production machine, the controller being connected to a manually operated user interface for setting the operation of the production machine. 
     The user interface can be disconnected from the robot in order to enter parameters offboard. 
     The device can be equipped with an autonomous navigation system designed for navigating the robot based on output signals of e.g. visual sensors of the robot. 
     The production machine can be self-containing. 
     The device can comprise an independent electrical power supply. 
     The production machine can be designed for producing the beverage or liquid comestible based on preportioned ingredients. 
     The device can have a container for a stock of preportioned ingredients portions. 
     The device can comprise automatic cup and tray handling system. 
     The device can comprise a cup storage lift, a cup prehensor (cup manipulator) and a tray storage lift, able to stock several trays, whereas a cup can be transferred from the cup storage lift to the upper tray, in order to move the cup under the coffee outlet for coffee preparation. 
     The invention also proposes a web based user interface for such a device, being designed for a selection of a coffee blend, a serving place and a serving time/date, using graphical presentation. 
     The invention also proposes an onboard interface for such a device, designed for ordering of a coffee directly on the robot, using graphical presentation. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS  
       Further object, features and advantages of the invention will become evident by the following detailed description of embodiments of the invention, taken in conjunction with the figures of the enclosed drawings. 
         FIG. 1  shows an application scenario for the present invention, 
         FIG. 2  shoes the mobile base of the robot with integrated PC, sensors, batteries and driving means, 
         FIG. 3  shows the gas bottle for pressure generation in peristaltic pump, pushing the hot water out of the thermos, going through a flowmeter and into the motorized brewing unit, 
         FIG. 4  shows the coffee outlet system, 
         FIG. 5  shows the capsule storage system, 
         FIG. 6  shows the cup handling and delivery system, 
         FIGS. 7 and 8  show details of the cup handling and delivery system, 
         FIG. 9  illustrates the cup lift operation, 
         FIGS. 10 to 13  illustrate a cup tray system with tray lift, 
         FIG. 14  illustrates the operation of the tray lift, 
         FIG. 15  shows a cup prehensor, 
         FIG. 16  shows the overall robotic device, 
         FIG. 17  illustrates the order logic, 
         FIG. 18  shows a detachable user interface (pocket PC, personal digital assistant PDA etc.). 
         FIG. 19  shows the detachable user interface in a state connected to the robot, 
         FIG. 20  shows an overview of the navigation system. 
     
    
    
     DETAILED DESCRIPTION OF THE INVENTION  
     The device according to the present invention is first of all a robot having the overall appearance as shown in  FIG. 16 . It can comprise two main parts: The fully autonomous mobile base as shown in  FIG. 2  and an automatic self-contained beverage (e.g. coffee production) machine, i.e. the robot carries its own resources such as electrical power, ingredients, liquid and computing power. 
     While autonomous guided vehicles (AGVs) usually employ for their navigation expensive and inflexible environment modifications such as floor tracks or reflectors as beacons, nowadays localization approaches are ready for unmodified environments, i.e. natural features. In fact the device according to the invention can be equipped with e.g. visual sensors (cameras etc.), in order to recognize its environment based on a pattern recognition of the output signals of the sensors. The environment of the robot can be previously programmed and stored in a memory of the onboard PC. The device according to the invention can thus act in an application scenario as shown in  FIG. 1 . 
     The following description is separated in four parts:
         1. Robot and its navigation system (mobile base of the robot)   2. Coffee machine working autonomously regarding the electrical power supply (i.e. no power cables)   3. Cup handling and delivery system   4. User Interface(s)
 
1. Robot (Mobile Base)
       

     The mobile Base shown in  FIG. 2  can be a differential drive system running e.g. the Bluebotics autonomous navigation technology (ANT®) (see bluebotics.com for further details), being one example for an autonomous navigation system. 
     The ANT technology will now be explained with reference to  FIG. 20 . The navigation is presented in three parts: Map; Planning and Motion; and Localization. 
     The map of the environment is a graph-like structure with nodes, points of interest the robot has to reach in order to perform a certain task. This graph is therefore used for path-planning. Furthermore it contains the information about all the features in the environment. This permits to calculate which feature is visible from the current position of the robot and to use it for localization. 
     Path Planning and Motion 
     ANT® implements three path planning algorithms. They work on different levels of abstraction and take sensor readings into account in varying degrees. The topmost layer is the graph-based global planner. It is based on the above mentioned graph structure where nodes are locations of interest and edges denote traversability between locations. The planner employs a depth-first search generating a lengthoptimal path. Since the path is global and no sensor readings are taken into account, dynamic path modification cannot be treated on this level. The second layer of path planning uses a navigation function in a local grid around the robot. It can thus take into account the current sensor readings and is not limited to nodes of the a-priori map. However, the paths have a very poor geometry, consisting of linear segments that lie on angles which are multiples of 45° and they have the tendency to graze obstacles. Smoothing the path and adapting it to dynamic surroundings is done in the third layer of path planning. It is based on the elastic band. The initial plan evolves toward a smoother curve (a list of via points) as long as the elastic band does not “snap”. In case dynamic obstacles move in such a way that the minimum clearance along the path cannot be maintained, or if the path lengthens beyond a reasonable amount, the program is called upon again to re-initialize the path. 
     The motion is under control of the real-time obstacle avoidance task, which is based on the dynamic window method permitting taking into account the actuator limits of the robot (speed which could result in later collisions are not allowed, motion commands never exceed the robot&#39;s speed or acceleration limits). Furthermore, the dynamic window takes into account the “exact” robot shape as represented by a convex polygon. 
     Instead of using the distance traveled before hitting an obstacle, the time until collision is used. This solves a singularity when the robot is turning on the spot (any collisions would seem instantaneous because the distance traveled seems zero). It also means the robot will choose more clearance when traveling at higher speeds. 
     The objective functions for speed, heading, and clearance are calculated on the actuator phase space. Actuator limits are thus more directly taken into account. 
     Localization 
     This method is a global feature-based multi-hypothesis localization using the Kalman filter as estimation framework. It overcomes limitations of the single-hypothesis Kalman filter, since the data association problem is explicitly addressed. The robot preserves the typical advantages of feature-based approaches, such as very high localization accuracy and an efficient implementation and adds an important feature in the case the robot looses the track of its position: It can generates hypotheses about its current position and therefore relocate itself. 
     The technique which provides this property is a constrained-based search in an interpretation tree. This tree is spanned by all possible local-to-global associations, given a local map of observed features and a global map of model features. The same search is consistently employed for hypothesis generation and pose tracking. 
     Embedded Automatic Coffee Machine 
     The embedded automatic coffee machine has to fulfil some specific technical rules in order work as an autonomous coffee machine. Issues like limited power consumption, fully automatic capsule handling with different blends, management of cups and trays had to be resolved. 
     The coffee machine is composed of three subassemblies: 
     The capsule storage and dispensing system, the coffee brewing system with hot water storage, pump system and extraction unit, and finally, the cup and tray system, allowing a fully automatic coffee preparation process onboard. 
     The mobile base is capable of moving, using its own active motion system (such as e.g. wheels driven by a electric motor of the robot) in a defined environment, taking into account moving objects like e.g. human beings. Preferably no physical guiding elements (lines, beacons etc.) are necessary, as the mobile base preferably but not necessarily is self-orienting according to real obstacles detected by its sensors (cameras, laser, tactile sensors etc.) and compared to a pre-programmed map, corresponding to the working environment. The map can be programmed by the robot base itself by using its sensors. 
     The mobile base contains the batteries for power supply, as well as the controller (control PC etc.) and communication means for the whole robot. 
     2. Autonomous Coffee Machine 
     The coffee machine integrated in the robot can use the gas technology, i.e. the production of beverages using a pressurized gas acting on a liquid reservoir  3 , shown in  FIG. 3 . 
       FIG. 1  shows a brewing unit  1  as well as a capsule dispensing mechanism  2 . The capsules represent one possibility to use preportioned ingredients. Other preportionings such as tea bags, pouches etc. can be used as well. Alternatively the portioning is carried out by the robot itself. 
     The coffee machine comprises the following parts: 
     A thermos watertank  3  including a peristaltic pump and active heating, allowing the water in the thermos to be kept at correct extraction temperature without major energy supply. The heater can work on power cord (heating up), and then becomes independent from cord, using a battery heating (keep warm). 
     The gas bottle  6  is used for pressure generation in peristaltic pump, pushing the hot water out of the thermos watertank  3 , going through a flowmeter  4  and into the motorized brewing unit  1 . 
     A coffee outlet system  7  (see  FIG. 4 ) with antidrip function by closing the outlet  7  into a vertical position when not dispensing coffee. The remaining coffee in the outlet is emptied through a second tube into the used capsule tray 
     A capsule storage system (e.g. several storage tubes) with its dispensing mechanism  2 , symmetrically disposed over two capsule ramps  5 , allowing the capsules to glide down over a central ramp  5   a  into the brewing unit  1  after having released a capsule at one of the several dispensing mechanisms  2 . 
     In the beverage production unit  1  hot water under pressure ins injected into the interior of the capsule in order to interact with ingredients contained in the capsule. (Generally in the brewing unit  1   a  liquid is brought in contact with ingredients which are preferably provided in preportioned packages.) 
     After extraction, the capsule is ejected into a used capsule tray. 
     3. Cup Handling and Delivery System ( FIGS. 6 to 15 ): 
     The Robot contains an independent cup handling system, comprising:
         a cup storage tube  12  with auto-regulating the cups in order to have always the upper cup  11  ready to be captured by a prehensor (cup manipulator)  10 . Furthermore, using sensors  16 ,  17 , the storage tube can accept fresh cups and autoregulate the cup lift  14 .       

     In fact, the cup lift is made by a motor driven  13  spindle  15  which moves a cup holder  14  along the vertical direction. The sensors  16 ,  17  autoregulate the position of cups in order the cup  11  to always be ready to be picked by the prehensor  10  and put on the tray  9 . The sensors  16 ,  17  work according to the principle shown in  FIG. 9 , whereas two sensors  16 ,  17  are placed on the top of the cup lift and one sensor is placed at the bottom of the lift.
         Cup tray system with autoregulating the trays  9  in order to have the upper tray always ready to get fresh cups, working according to the principle shown in  FIG. 14  and including sensors  17 . The four tubes  23  on each cup position on the tray allow to detect the presence of a cup on the tray by containing optical sensors. Several trays can be stacked on a tray lift in order to take them away for serving coffee at a table and allowing the robot to put the next four cups on the following tray, which moves up to the correct position, once the full tray has been removed from the robot. The tray lift works according to the same principle than the cup lift. Furthermore the tray system consists of a fixed chassis  8 , holding trays mounted on a carousel  21 , allowing to move the cup to be moved under the coffee outlet  7 . The rotation of the tray is made by a motor  20  and two corresponding gears  21 ,  22  around the axis  18 . The vertical moving of the trays is made by a second motor  19  and a central spindle  24 . By blocking the tray rotation relatively to the carousel  21  thanks to the four cup detecting tubes  23 , the trays can be lifted up and down.       

     The trays  9  have numbered positions in order to identify the coffee blend served. Furthermore the tray carousel is indexed in order to know which coffee is served in which cup.
         A cup prehensor (see particularly  FIG. 15 ) for transferring a cup from the cup storage tube onto the cup tray       

     The cup prehensor comprises a chassis  26  and two motors, one  27  allowing the positioning of a cup onto a tray, one  28  the prehensing of a cup  11  ready in the cup storage lift. 
     General Functional Description 
     The process of coffee ordering can be described as following:
         1. Receiving of a coffee order using one of the interface explained below.   2. A Cup is put on tray by the prehensor. The cup lift moves up next cup. The prehensor moves back in standby position over cup.   3. Release of the desired capsule, which is gliding into the brewing head   4. The cup tray is turning 90° in order to put the cup under coffee outlet   5. The coffee outlet is opening and brewing head closing.   6. Extraction of coffee   7. Coffee outlet is closing and brewing head opening, ejecting the extracted capsule into a capsule tray.   8. Cup is ready to be taken away by user, or alternatively the whole tray, tray lift moves up next tray.
 
4. User Interface
       

     The user interface(s) is/are one of the elements of the system. There can be in fact at least two different interfaces:
         The first one is relying on a air interface of the robot connected to a controller of the robot. Using the air interface, e.g. a web-based application can permit the ordering from any remote web browser in a secured intranet network. Alternatively the air interface of the robot can be designed for any speech or data (such as e.g. text messages) based wireless communication.   The second interface relies on a detachable manually controlled user interface, such as e.g. a pocket PC, a PDA, a remote control, which can be placed and connected on the robot. The detachable user interface can be used directly on the device according to the present invention (onboard) to choose the coffee blends, or it can be detached and used off-board allowing the users choosing their blends for example around a conference table.       

     The tow ordering systems can be designated as Remote Ordering (Intranet) and Direct Ordering (Pocket PC) onboard robot or offboard robot (conference room) 
     The graphs of  FIG. 17  explain a typical order placing on a Desktop PC, via a protected intranet network: 
     The web-based application firstly asks to choose either the blends you want or if you only want a visit of the robot. Finally, the user interface permits choosing the place and time to meet the robot. To this regard the graphical interface illustrates the environment e.g. by displaying a map. The user can then, using the map, specify a target location. 
     The user can specify the desired location where he/she wants the coffee to be produced. The user can choose, if he just wants the robot to move to the desired instructed location without preliminary coffee order, or he/she can order directly a cup of coffee, choosing the desired blend. Using the transmitted information on the desired position for the dispensing of the beverage, its current position and its navigation system, the robot will move autonomously to the desired place at the desired time (if any) and will start prepare coffee, if a coffee order has been placed. All this operations occur without external human influence. 
     If several people order a coffee at the same time, a queuing list is established by the robot like for a printer queue. 
     Several conflicts can be handled by implementing priority rules (e.g. conference rooms are served prior to individual orders) 
     Once all coffees at a defined place have been served, the robot continues to move either to the next order point or to a docking station for recharging. 
     The Pocket PC is placed on the Robot, in order to show the tray occupancy (which blend in which cup) and allows direct onboard coffee ordering, by simply clicking on the desired blend. After ordering, the robot immediately starts coffee preparation. As mentioned before, the Pocket PC can be removed from the robot in order to make coffee orders around a conference table (offboard coffee ordering). 
     Fully autonomous coffee machine, serving automatically coffee without external influence, except the order process.