SERVING SYSTEM AND SENSOR DEVICE FOR PICK-AND-MIX SALES

Abstract

A sensor device (8, 15, 20) for monitoring the volume of granular food or candy contained in a pick-and-mix container (2), wherein the sensor device (8, 15, 20) comprises at least one pair of electrodes (10, 11), a capacitance meter (12) and a controller (13). The capacitance meter (12) is connected to the at least one pair (9, 16) of electrodes (10, 11, 17, 18) and operable to measure the capacitance over the at least one pair (9, 16) of electrodes (10, 11, 17, 18) to produce an output indicative of the capacitance through the container (2). The controller (13) is operable to determine and report a content level of the container (2) based on at least the output of the capacitance meter (12) and calibration data related to the type of container and/or to the type of content, and/or operable to monitor the output of the capacitance meter (12) to determine a state of low content level based on at least the output of the capacitance meter (12) and calibration data related to the type of container and/or to the type of content, and to emit an alert signal upon determination of said state of low content level.

Claims

1. A sensor device for monitoring the volume of granular food or candy contained in a pick-and-mix container, wherein the sensor device comprises at least one pair of electrodes, a capacitance meter connected to the at least one pair of electrodes and operable to measure the capacitance over the at least one pair of electrodes to produce an output indicative of the capacitance through the container, and a controller operable to determine and report the content level of the container based on at least the output of the capacitance meter and calibration data related to the type of container and/or to the type of content, and/or operable to monitor the output of the capacitance meter to determine a state of low content level based on at least the output of the capacitance meter and calibration data related to the type of container and/or to the type of content, and to emit an alert signal upon determination of said state of low content level.

2. A sensor device according to claim 1, wherein said at least one pair of electrodes comprise at least two pairs of electrodes.

3. A sensor device according to claim 2, wherein said at least two pairs of electrodes share at least one mutual electrode.

4. A sensor device according to claim 2, wherein the at least two pairs of electrodes are connected in parallel such that the meter is operable to jointly measure the capacitance in the at least two pairs of electrodes.

5. A sensor device according to claim 2, wherein the meter is operable to separately measure capacitance between the electrodes in each respective pair of electrodes and account for the characteristics of each respective pair of electrodes at production of said output of the meter.

6. A sensor device according to claim 1, wherein the capacitance meter is configured to use a plurality of capacitance measurements to calculate an average and base the meter output on the calculated average.

7. A sensor device according to claim 1, said controller being configured to temporarily disable capacitance measurement in response to an input signal indicative of the running state of a nearby electric motor, wherein capacitance measurement is disabled when the input signal indicates the motor is running, and wherein capacitance measurement is enabled when the input signal indicates the motor is not running.

8. A sensor device according to claim 1, wherein said electrodes comprise metal foil or tape connected to the capacitance measuring device.

9. A sensor device according to claim 8, wherein said metal is copper or aluminum.

10. A sensor device according to claim 1, wherein the electrodes are substantially planar and comprise a respective bottom portion and a respective top portion, said bottom and top portions being foldable such that the bottom portion extends substantially perpendicularly to the top portion.

11. A sensor device according to claim 1, further comprising a light source for visually indicating low content in the container, said controller being operable to activate said light source to emit light in response to said alert signal indicating low content.

12. A serving system comprising a sensor device according to claim 1 and said container, wherein the electrodes of each respective pair of electrodes are provided on opposite sides of the container for measuring capacitance through the container.

13. A serving system comprising a sensor device according to claim 2, said serving system further comprising said container, wherein the electrodes of each respective pair of electrodes are provided on opposite sides of the container for measuring capacitance through the container, and wherein the pairs of electrodes are positioned apart from each other for measuring capacitance through different portions of the container.

14. A serving system comprising a sensor device according to claim 1, wherein the electrodes are attached directly onto the outside of the container.

15. A method of calibrating a serving system according to claim 12 for a specific type of content, comprising the steps of for a plurality of different fill levels of the container operating the capacitance meter to record for each fill level reference values for the capacitance for each respective pair of electrodes, and based on the recorded values prepare calibration data related to the type of container and/or to the type of content, such that the calibration data relates capacitance values to a contained content level for the specific type of container and/or to the type of content used for performing the method.

16. A computer readable storage medium encoded with instructions that, when executed on a processor, perform the method according to claim 15.

Description

DETAILED DESCRIPTION

[0035] The disclosed embodiments will hereinafter be described in more detail with reference to the accompanying drawings in which some embodiments of the invention are shown. This invention may, however, be embodied in many different forms and should not be construed as limited to the embodiments set forth herein. Rather, these embodiments are provided by way of example so that this disclosure will be thorough and complete, and will fully convey the scope of the invention to those skilled in the art. Like numbers refer to like elements throughout.

[0036] FIG. 1 shows a serving system 1 according to a first embodiment of the invention. The serving system comprises an empty pick-and-mix container 2. A pick-and-mix container is any container suitable for being used in a pick-and-mix environment in a store. The container 2 shown is of a known wall or rack mounted type as described in the background. The container 2 has a body of clear plastic and is provided with a front opening 3 covered by a lid 4 attached to the body by a hinge means such that it can be readily opened and closed. A suitable material for the container 2 is PMMA, commonly known as acrylic glass, although other materials are possible as long as they allow for capacitive measurement through the container 2.

[0037] The container 2 has a lower compartment 5 provided with the front opening opening 3 configured such that candy is accessible for being picked by a customer through the front opening 3. The container 2 also has an upper compartment 6 extending upwards from the lower compartment 5 to increase the storage capacity of the container 2. A lower portion of the upper compartment 6 is open into the lower compartment 5 such that candy inside the upper compartment 6 can move into the lower compartment 5 by the force of gravity upon content being picked from the lower compartment 5. In some embodiments (not shown), the lower back of the container 2 is forwardly slanted for items of content to be forced forwards in the container by gravity towards the lower opening 3.

[0038] The container 2 shown is preferably filled through its upper opening 7 and emptied through the front opening 3. The upper opening 7 may in other embodiments be provided with a lid (not shown) to protect it from dust and contamination.

[0039] The serving system 1 further comprises a sensor device 8 also shown separately in FIG. 3. The sensor device 8 comprises a pair 9 of electrodes 10, 11. The pair 9 of electrodes 10, 11 are provided on opposite sides of the container 2 for measuring capacitance through the container 2. The electrodes 10, 11 are adhesive copper tape applied directly onto the outside of the container 2. Another feasible electrode material is aluminum. Instead of using tape, various forms of foils or plates could be used as electrodes. The distance between container 2 and electrode 10, 11 should preferably be kept low and static since any gap affects the capacitance readings made.

[0040] The sensor device 8 also comprises a capacitance meter 12 and a controller 13. The capacitance meter 12 is connected to the pair 9 of electrodes 10, 11 and operable to measure the capacitance over the electrodes 10, 11 to produce an output indicative of the capacitance through the container 2.

[0041] The capacitance meter 12 comprises a Smartec Universal Transducer Interface IC, although other metering components/ICs are feasible within the scope of the present invention. The Smartec Universal Transducer Interface is operable to measure several capacitances simultaneously using MUX, which enables several containers 2 to be monitored by a single sensor device using only one IC.

[0042] People operating the serving system 1 may be interested in detailed continuous information of the content level in the container 2.

[0043] The term content level is here used broadly to refer to any suitable measurement reference system of choice. For example, a reference system may be continuous such as percentage of current volume contained vs maximum volume contained. Alternatively, it may be discrete, such as having a plurality of named levels: Full, Nearly full, Nearly empty and Empty or similarly numeric levels 1, 2, 3 and 4. Further, the content level could refer to the specific current volume contained, without relating it to the maximum volume that the container 2 can contain. Alternatively, it could describe the approximate weight of product contained.

[0044] For example, one may be interested in the current content level to be able to know how much product need be taken from back-office/a warehouse, loaded onto a cart and brought out into the store to refill the containers 2 containing a specific type of product. Preferably only one walk into the store to refill the containers is necessary. By knowing the current content level, the risk of bringing too much or too little new product from back-office into the store is reduced. Altogether, the continuous information saves precious time for the store personnel.

[0045] One may also be interested in tracking the content level over time in order to effortlessly be able to derive picking rates and predict when a specific container is likely to run empty or predict the expected content level in a container at a specific point of time. If personnel are scheduled to refill the containers at a specific time, it would be advantageous to be able to know what types of content they should bring to the store and how much should be brought from back-office to the store. The amount needed for refill at a specific time in the future can be calculated using the current levels and applying the knowledge of predicted picking rates gained by historic tracking of content levels.

[0046] To be able to continuously track the content level the controller 13 may in some embodiments be configured such that it is operable to determine and report a content level of the container 2 based on at least the output of the capacitance meter 12 and calibration data related to the type of container 2 and/or to the type of content.

[0047] In other use cases where continuous or on demand information is not of interest, it may for some embodiments suffice to configure the controller 13 such that it is operable to monitor the output of the capacitance meter 12 to determine a state of low content level based on at least the output of the capacitance meter 12 and calibration data related to the type of container 2 and/or to the type of content, and to emit an alert signal upon determination of said state of low content level.

[0048] In the embodiment depicted in FIG. 1, the controller 13 is configured to do both; ie. to determine and report a content level, and to monitor and determine a state of low content and emit an alert signal when the low level is detected.

[0049] As the skilled person will understand, there are many ways in which to configure a sensor device 8, 15, 20 to report a content level of the container 2 based on at least the output of its capacitance meter 12 and calibration data related to the type of container 2 and/or to the type of content. This will be discussed in more detail below.

[0050] What we want to achieve is to establish the relationship between capacitance and volume contained and save this information for use in operation of the sensor device. Basically, calibration of the sensor device 8, 15, 20 means that we have to study the capacitance through the container 2 for a plurality of known volumes of content in the container 2 and use the results of the study to establish a mathematical model for the relationship, or establish a look-up table for the relationship.

EXAMPLE

Deriving Calibration Data

[0051] A new sensor device 15 is unpacked for attachment to an existing container 2. Then, the electrodes 10, 11, 17, 18 of each respective pair 9, 16 of electrodes 10, 11, 17, 18 of the sensor device 15 are attached to opposite sides of the container 2 for measuring capacitance through the container 2. The electrodes 10, 11, 17, 18 may be provided with self-adhesive backing such that attachment is easy and does not require tools. The sensor device 15 is then connected to a power source (not shown), such as a wall outlet, battery or photovoltaic panel. Thereafter, the container 2 is filled with the specific content type of choice. Subsequently, the sensor device 15 is put in a calibration mode, such as by pushing a physical button or operating a software-implemented user interface. Thereafter, the container 2 is gradually emptied wherein the sensor device 15 records a capacitance measurement for each fill-level, either continously or in a number of discrete steps. The sensor device 15 is informed, directly or indirectly, of the decrease in content during emptying, so that the sensor device 15 can keep track of what the capacitance measurement(s) is/are for a specific volume/weight/fill-height of content.

[0052] One way of informing the sensor device 15 of the decrease in content is to remove content batchwise in known discrete steps, for example with a full scoop of candy in each step, such that the sensor device 15 can detect the sudden change of capacitance upon removal of content. Such automatic detection would constitute such indirect information. Alternatively direct information is used, wherein a person pushes a physical button or operates a computer implemented graphical user interface to tell the sensor device 15 that a decrease in contained volume has occurred. An alternative way of informing the sensor device 15 would be to remove content in constant known pace until empty, for example using a specially developed electromechanical feeding device for feeding content out of the container 2. When the removal rate is known, for example by measuring the time it takes for the feeding mechanism to fully empty the container 2, and knowing the volume of the container 2, it is possible to simply make capacitance measurements continously in regular interval and note the time elapsed.

[0053] Using any of the above mentioned discrete or continous emptying processes, it is thus possible to derive the calibration data needed for future use of the sensor device 15 for measuring the level of content in the container 2.

[0054] Upon each measurement, the capacitance meter 12 of a sensor device 15 activates a pair 9, 16 of electrodes 10, 11, 17, 18 in order to measure capacitance between them within the pair. The capacitance meter 12 outputs a measurement value or a series of measurement values over time. The capacitance meter 12 is typically capable of making a plurality of measurements and report an average value.

[0055] It should be understood that the capacitance, and hence the measurement value, will be different for a given level of content in the container 2 depending on the type of content. For example, measurements on a half-full container 2 will typically render different measurement values for different types of content, ie. different capacitance for different types of candy.

[0056] FIG. 6 shows capacitane measured for varying amounts of content of a container with the same type of content for all measurement values. For each volume, two values are plottedone for a first pair of electrodes attached to a front portion of the container to measure capacitange through the front portion of the container, and another value for a second pair of electrodes attached to a back portion of the container for measuring capacitance through a back portion of the container. The capacitance variance between front and back of the container indicates that the content is not evenly distributed throughout the container. For this type of content, the relation between capacitance and volume follows a roughly linear curve with some amount of standard deviation. For other content types, the relation may exhibit a bent or curved relationship rather than a linear, which would then be possible to approximate by an nth degree function, such as a quadratic or qubic function, such that said function could be used to derive a volume based on a capacitance measurement. Once a suitable function with suitable function parameters are found, this information stored as calibration data along with information on type of content and possibly also along with information on type of container used for calibration. For example, one may be interested in knowing the type of container used for obtaining the calibration data in cases where tests have shown there is an important individual variance in how much specific containers of a given type affect capacitance measurements. In other cases, the individual containers shows not to affect capacitance reading much, wherein the container data may be less useful and omitted.

[0057] There are many ways in which the low level state can be communicated to people or computer systems. For example, a wired or wireless alert signal could be sent to a personal computer, smartphone or to a server storing or relaying the information as needed. A basic and intuitive way of communicating a state of low content level of a container 2 is achieved by the serving system 1 shown in FIG. 1 which uses the sensor device 8 shown in FIG. 3. The serving system 1 comprises a light source 14 for visually indicating low content in the container and the controller 13 is operable to activate said light source 14 to emit light in response to said alert signal indicating low content. Thus, store personnel can relax as long as the light source 14 is not lit and return to refill the container 2 once the light source 14 is lit. Instead of a light source, a personal computer or handheld computing device, such as a phone or tablet, could be used for communicating the alert. Alternatively, the controller could be configured to trigger sending of digital message, such as an email, an SMS, an MMS, or a Push Notification, to one or more recipients in order to alert them.

[0058] It should be understood that depending on refill strategy, low level state should not always be determined at the same content level or capacitance for all containers and content types. For example, more popular content types may need to be refilled more often, and as a result may need to send the alert signal earlier than what would be needed for less popular content types and times of day/week. Thus, the sensor device 8 may be configured to determine low level state at least partly based on content type and scheduled demand in addition to capacitance.

[0059] Also, it should be understood that the invention is not limited to this type of container 2 but could also be used with other types of containers suitable for the pick-and-mix concept. For example, the container could be the dispenser/container described in European patent EP2787863 which features an electromechanical feeding mechanism comprising a conveyor screw extending through the content of the container. The conveyor screw is made of metal and rotational orientation affects capacitance readings. Further, the action of the conveyor screw results in unevenly distributed content within the container, which also tends to affect capacitance readings through the container.

[0060] In order to mitigate the problems associated with disturbances from the electrical motor driving the feeding mechanism it is proposed to in some embodiments configure the controller 13 to temporarily disable capacitance measurement in response to an input signal indicative of the running state of a nearby electric motor, wherein capacitance measurement is disabled when the input signal indicates the motor is running, and wherein the capacitance measurement is enabled when the input signal indicates the motor is not running.

[0061] A second embodiment of a serving system according to the invention is shown in FIG. 2. The second embodiment of the serving system differs from the first embodiment in that it uses an alternative sensor device 15 shown separately in FIG. 4. The alternative sensor device 15 differs from the first sensor device 15 in that is comprises two pairs 9, 16 of electrodes instead of one pair 9 of electrodes. The provision of two pairs 9, 16 of electrodes enables measurement of capacitance in two separate portions of the pick-and-mix container 2, here a back portion and a front portion. By being able to measure capacitance in two portions of the container 2, any uneven distribution of content between the portions can be taken into account then determining the content level of granular food or candy contained. This improves accuracy and is important in pick-and-mix systems where the distribution of content in the container 2 is affected by customers picking by hand, or affected by a feeding mechanism moving said content within the container 2.

[0062] FIG. 5 shows a schematic view of a sensor device 20 according to an embodiment of the invention in which the sensor device 20 comprises two pairs 9, 16 of electrodes sharing a mutual electrode 11, 17. Such a sensor device 20 may be used for capacitance measurement through two containers (not shown) positioned side-by-side. The use of a mutual electrode 11, 17 thus enables a great decrease in the number of electrodes needed to enable measurement in a line of containers positioned side-by-side. The mutual electrode 11, 17 may have the same design as any other electrode and what makes it a mutual electrode 11, 17 is rather the configuration of the capacitance meter 12 which has to be made such that the meter 12 can selectively use the mutual electrode 11, 17 for measurements in different pairs 9, 16 of electrodes.

[0063] The controller 13 may be implemented using instructions that enable hardware functionality, for example, by using executable computer program instructions in a general-purpose or special-purpose processor that may be stored on a computer-readable storage medium (disk, memory, etc.) to be executed by such a processor. The controller 13 is configured to read instructions from the memory and execute these instructions to control the operation of the sensor device 1 including, but not being limited to the above described functions. The controller 13 may be implemented using any suitable, publicly available processor or Programmable Logic Circuit (PLC). The memory may be implemented using any commonly known technology for computer-readable memories such as ROM, RAM, SRAM, DRAM, FLASH, DDR, SDRAM or some other memory technology.

[0064] The computer-readable medium may be a data disc (not shown). In one embodiment the data disc is a magnetic data storage disc. The data disc is configured to carry instructions that when loaded into a controller 13, such as a processor, execute a method or procedure according to the embodiments disclosed above. The data disc is arranged to be connected to or within and read by a reading device, for loading the instructions into the controller 13. One such example of a reading device in combination with one (or several) data disc(s) is a hard drive. It should be noted that the computer-readable medium can also be other mediums such as compact discs, digital video discs, flash memories or other memory technologies commonly used. In such an embodiment the data disc is one type of a tangible computer-readable medium.

[0065] The instructions may also be downloaded to a computer data reading device, such as the controller 13 or other device capable of reading computer coded data on a computer-readable medium, by comprising the instructions in a computer-readable signal which is transmitted via a wireless (or wired) interface (for example via the Internet) to the computer data reading device for loading the instructions into a controller 13. In such an embodiment the computer-readable signal is one type of a non-tangible computer-readable medium.

[0066] The instructions may be stored in a memory of the computer data reading device.

[0067] References to computer program, instructions, code etc. should be understood to encompass software for a programmable processor or firmware, such as the programmable content of a hardware device whether instructions for a processor, or configuration settings for a fixed-function device, gate array or programmable logic device.

[0068] The inventive technology is not only to be provided as a serving system 1 comprising a container shipped with sensors and electronics, but also as a so called sensor device for retrofitting to existing pick-and-mix systems to convert them to into smart systems. FIGS. 3 and 4 show a first and a second embodiment of a sensor device according to the invention. The first embodiment of sensor device corresponds to the one used in the serving system 1 depicted in FIG. 1. The second embodiment of sensor device corresponds to the one used in the serving system 19 depicted in FIG. 2.

[0069] As mentioned, the invention has been described herein with reference to a few embodiments. However, as is readily appreciated by a person skilled in the art, other embodiments than the ones disclosed above are equally possible within the scope of the invention, as defined by the appended patent claims.