METHOD FOR CHECKING A TOUCH SCREEN FOR CONTAMINATION BY AT LEAST ONE CONTAMINATION, ASSOCIATED COMPUTER PROGRAM AND ELECTRONIC CONTROL SYSTEM

Description

[0001] The present invention relates to a method for controlling contamination by at least one contaminant of a touch screen of an installation.

[0002] The invention also relates to a computer program comprising software instructions which, when executed by a computer, implement such a generation process.

[0003] The invention also relates to an electronic system for controlling contamination by at least one contaminant of a touch screen of an installation.

[0004] Here, "contaminant" refers to a chemical, viral, or bacteriological substance.

[0005] The invention relates to the field of preventing contamination by touch of a contaminated surface.

[0006] It is possible to transmit a contaminant through successive contact with the same surface by several people. For example, a first person carrying a contaminant on their hands deposits the contaminant onto the surface during the first contact. Then, during a second contact, a second person touches the contaminated surface; the contaminant, now present on the surface, adheres to the second person's hand, thus becoming infected.

[0007] Therefore, it is useful to detect possible surface contamination in the context of surfaces touched repeatedly by a plurality of users.

[0008] US patent 2014 / 023266 2 A1 describes such detection. Specifically, this patent describes the presence of a sensor configured to determine, prior to the user's contact with the surface, the presence of contaminants on the user's hand. For this purpose, the sensor is capable of detecting an odor or taste indicative of the contaminant. Alternatively, the sensor uses piezoelectric or micro-biosensitive chromogen technology.

[0009] However, the identification of each contaminant then depends heavily on the sensor and / or its calibration. Indeed, sensors configured to detect a certain type of contaminant are often ineffective at detecting other types of contaminants. Thus, if it were decided to identify a new contaminant, it would then be necessary to physically adapt the sensor(s) to that contaminant.

[0010] We also know of documents US 2021 / 052756 A1, WO 2019 / 136381 A1, US 2020 / 279642 A1, and JP 2018 084974 A of processes for controlling contamination by at least one contaminant.

[0011] The object of the invention is therefore to propose a simpler contamination control method that can be integrated into an existing device.

[0012] To this end, the invention relates to a method for controlling contamination by at least one contaminant according to claim 1.

[0013] Advantageously, with the method according to the invention, it is not necessary to determine beforehand a way to detect each contaminant individually. Thus, the method is simpler to integrate into an existing device.

[0014] According to other advantageous aspects of the invention, the control method is according to any one of claims 2 to 9.

[0015] The invention also relates to a computer program product according to claim 10.

[0016] Furthermore, the invention relates to an electronic system for controlling contamination by at least one contaminant according to claim 11.

[0017] These features and advantages of the invention will become clearer upon reading the following description, given solely by way of non-limiting example, and made with reference to the accompanying drawings, in which: [ Fig. 1 ] there figure 1 represents an installation comprising an electronic control system; [ Fig. 2 ] there figure 2 is a schematic view of a touchscreen installation of the figure 1 , on which the unit surfaces are represented; [ Fig. 3 ] there figure 3 represents a flowchart of an implementation method for a control process implemented by the electronic control system of the figure 1 , And [ Fig. 4 ] there figure 4 represents an example of the temporal evolution of a contamination indicator on a unit surface of a touchscreen included in the installation of the figure 1 .

[0018] With reference to the figure 1 For example, a 10-unit installation is located within a station hall. A 10-unit installation is, for example, a ticket vending machine. A ticket is a right to travel stored on a ticket, a smart card, or a smartphone (from English). smartphone ), or another electronic device suitable for storing this ticket. For example, tickets sold by installation 10 are travel rights for a metro, bus, tram, or train.

[0019] Alternatively, installation 10 is a parking ticket vending machine.

[0020] Alternatively, installation 10 is an audiovisual system embedded in a vehicle such as an airplane, train or boat.

[0021] The installation 10 is designed to offer services or goods to a user 15. For this purpose, the installation 10 includes a touch screen 20 and an electronic service device 25.

[0022] The touch screen 20 is configured to display content from the electronic service device 25, and is specifically designed to display user-selectable content 15.

[0023] In turn, the touchscreen 20 is adapted to receive user commands via digital touch. More specifically, the touchscreen 20 is configured to transmit to the electronic service device 25 a signal representing a touch and the location of that touch by the user 15.

[0024] As is known, the touchscreen 20 comprises a display (not shown) and a plurality of sensors (not shown). The display is configured to show selectable content from the electronic service device 25.

[0025] The sensors are configured to detect a user touch 15 and to determine the x0, y0 coordinates of a center of the touch, in a predetermined frame of the touch screen 20, for example an orthogonal frame having its origin at the bottom left of the screen 20.

[0026] The touch screen 20 is then able to send to the electronic service device 25, a selection signal including the coordinates x 0 , y 0 of the user's press 15.

[0027] As an optional addition, the touch screen 20 is capable of sending the selection signal as long as the user 15 maintains their press on the screen 20.

[0028] Alternatively, the sensors are configured to determine a set of coordinates x0, y0, x1, y1, x2, y2, corresponding to several points of contact of the user 15 on the display. The set of contact points then includes several points that are substantially close to each other since they correspond to the contact of a finger of the user 15. The term "substantially close" is understood here to mean a distance between 1 and 3 centimeters, corresponding to the length or width of a finger joint.

[0029] The electronic service device 25 includes an electronic processing system 30 and an electronic control system 35.

[0030] The electronic processing system 30 is configured to interact with the user 15 to provide him with the services or goods he desires.

[0031] The electronic processing system 30 includes an acquisition / sending module 40 and a processing module 45.

[0032] The acquisition / sending module 40 is configured to acquire the selection signal from the touch screen 20. It is also configured to transmit, to the touch screen 20, the content to be displayed, from the processing module 45.

[0033] The processing module 45 is configured to process the selection signal received by the acquisition / transmission module 40.

[0034] Furthermore, the processing module 45 is configured to determine the content to be displayed. This determination is, for example, a consequence of receiving the selection signal.

[0035] More specifically, the content to be displayed comprises several pages and includes, on each page, at least one selectable box. Examples of selectable boxes include a confirmation button, a page-turn arrow, a scroll wheel, and a zoom icon. The content also includes the geometric parameters of each page, that is, the geometric dimensions of each box and its location on the 20-inch touchscreen once the page is displayed.

[0036] Following a selection of a cell by the user (15), such as zooming in, the geometric dimensions and / or location of that cell may change. Therefore, the content settings may evolve even without a page change.

[0037] In the example of a ticket vending machine, the initial displayed content might include a message asking the user 15 how many tickets they wish to purchase. This content also includes a number of boxes containing digits, for example, from 1 to 10. The touchscreen 20 is then configured to display this content, meaning that each element of the content is displayed at a position predetermined by the processing module 45.

[0038] In this example, the selection signal includes, for example, the coordinates relative to the box indicating the number 1.

[0039] The processing module 45 is configured to, in such an example, generate new content including a message inviting user 15 to pay a predefined fare corresponding to a transport ticket.

[0040] The electronic control system 35 includes a receiving module 50, a determining module 55, a detecting module 60, an updating module 65, an estimating module 70, a learning module 73, and a transmitting module 75. The learning module 73 is optional.

[0041] The electronic control system 35 is configured to control a quantity of contaminants on the touch screen 20.

[0042] The receiving module 50 is configured to receive the selection signal from the plurality of sensors on the touch screen 20 or from the acquisition-sending module 40.

[0043] As an optional addition, the 50 receiver module is configured to record a time at which the selection signal is received, called the reception time.

[0044] As an optional additional feature, the receiver module 50 is configured to record the duration of the user's press 15. For this purpose, the receiver module 50 is configured to record the duration during which it receives, from the touch screen 20, the selection signal including the same coordinates x 0 , y 0 .

[0045] Alternatively, the receiver module 50 is also configured to receive information on an outside temperature, from a temperature sensor not shown.

[0046] As an optional addition, the receiving module 50 is configured to receive, from the electronic processing system 30, the settings for each page of the content to be displayed.

[0047] The determination module 55 is configured to determine at least one unit surface 80 on the touch screen 20. The touch screen 20 comprises at least two unit surfaces 80.

[0048] Thus, the determination module 55 is then preferentially configured to determine at least two unit surfaces 80 of the touch screen 20.

[0049] For this purpose, the determination module 55 is configured, for example, to define a tiling of the touchscreen 20 in which each element (or tile) is a respective unit surface 80. Preferably, each unit surface 80 has the same geometry and dimensions as another respective unit surface 80.

[0050] For example, each unit surface 80 is rectangular, and its length and width are each between 5mm and 2cm. Thus, in the example of the figure 2 , the determination module 55 is configured to perform a grid of the touch screen 20 in which each grid element corresponds to a respective unit area 80.

[0051] Alternatively, each unit surface 80 is triangular, pentagonal or hexagonal.

[0052] Each unit surface 80 then comprises vertices and sides.

[0053] Each unit surface 80 is, for example, delimited by the coordinates of its vertices. The determination module 55 is then configured to determine the coordinates of the vertices of each unit surface 80.

[0054] Alternatively, the determination module 55 is configured to dynamically determine each unit surface 80, following the reception, by the receiving module 50, of the selection signal.

[0055] The detection module 60 is configured to detect the unit surface(s) 80 that have been pressed by the user 15, from the selection signal received by the receiving module 50.

[0056] More specifically, the detection module 60 is configured to detect the unit surface 80 that has been supported, based on the coordinates x0, y0, x1, y1, x2, y2 included in the selection signals. On the figure 2 The detected unit surface(s) 80 are hatched.

[0057] The detection module 60 is configured to perform such detection according to one of the following detection modes, shown on the figure 2 .

[0058] According to a first detection method, represented in the upper left of the figure 2 , the detection module 60 is configured to, when the selection signal includes the coordinates x 0 , y 0 of a single point, detect the unit surface 80 which has been supported, as being the surface 80 which geometrically includes the point with coordinates x 0 , y 0 .

[0059] Furthermore, since the boundaries between each unit surface 80 are of zero thickness, the coordinates x 0 , y 0 of each support are contained within a respective unit surface 80.

[0060] As an optional addition, according to the first detection mode, the detection module 60 is configured to, if the coordinates x 0 , y 0 of a support are included in a respective unit surface 80 but are distant from a boundary of this surface 80 by at most a first value, also detect the surface 80 adjacent to the surface 80 which has been supported as having also been supported.

[0061] According to a second detection method, shown in the bottom left corner of the figure 2 , the detection module 60 is configured to, when the selection signal includes the coordinates x 0 , y 0 of a single point, determine a first peripheral zone Z1 around the point with coordinates x 0 , y 0 .

[0062] The detection module 60 is then configured to detect the unit surface(s) 80 that have been touched by the user 15 as being covered by the first peripheral zone z1 by at least a predefined percentage P. If the percentage P is close to 0 percent, then every unit surface 80 covered, even very partially, by the first peripheral zone z1 is detected. Conversely, if the percentage P is close to 100 percent, the detected unit surface(s) 80 correspond to unit surfaces that are substantially entirely covered by the first peripheral zone z1.

[0063] The first peripheral zone z1 is for example circular, of a predefined radius, and centered on the point of coordinates x0, y0. The radius is notably between 25mm and 1cm.

[0064] Alternatively, the first peripheral zone z1 is elliptical. Its major and minor axes are then predefined. The point with coordinates x0, y0 is, for example, the center, or one of the foci, of the first peripheral zone z1. The minor and major axes of the first peripheral zone z1 are, in particular, between 25 mm and 1 cm.

[0065] According to a third detection method, shown in the bottom right corner of the figure 2 , the detection module 60 is configured to, if the selection signal includes the coordinates x 0 , y 0 , x 1 , y 1 , x 2 , y 2 of several points, detect the unit surface(s) 80 having received user support 15 as being the unit surface(s) 80 comprising each of the coordinate points received in the selection signal.

[0066] According to a fourth detection mode, shown in the upper right corner of the figure 2 The detection module 60 is configured to determine, if the selection signal includes the coordinates x0, y0, x1, y1, x2, y2 of several points, a second peripheral zone z2 around these points using an optimization algorithm, such as the least squares algorithm. To this end, the detection module 60 is configured to determine the second peripheral zone z2 having a predefined shape, including each of the points with coordinates x0, y0, x1, y1, x2, y2, and whose parameters are optimized by applying a least squares algorithm according to a known technique.

[0067] If the second peripheral zone z2 is, for example, circular, the parameters are the coordinates of the center of the second zone z2 and its radius. If the second peripheral zone z2 is, for example, elliptical, the parameters are then: the coordinates of one of the zone's foci, the minor axis, the major axis, and the orientation of the major or minor axis.

[0068] According to the fourth detection mode, the detection module 60 is configured to detect the unit surface or each unit surface 80 that has been supported in a manner analogous to the second detection mode but from the second peripheral zone z 2 instead of the first peripheral zone z 1.

[0069] Alternatively, the detection module 60 is configured so that, if the receiving module 50 receives a plurality of selection signals temporally separated from each other by at most one second value, and having coordinates contained within the same unit surface 80 or within adjacent unit surfaces 80, then detect each unit surface 80 including the coordinates of a selection signal and generate a weight greater than 1 for the unit surfaces 80 for which the received coordinates are closer to the center than to a boundary of said surface 80.

[0070] Update module 65 is configured to update an indicator of the number of supports per unit area 80. The indicator of the number of supports per unit area 80 is, for example, a support counter, or a support frequency estimator.

[0071] The update module 65 is configured to, if the support count indicator per unit area 80 is a support counter, increment the counter for each unit area 80 detected by the detection module 60.

[0072] The update module 65 is configured to, if the support number indicator is a support frequency estimator, update said estimator for each unit area 80 by accumulating the number of supports, over a first sliding time window of a predetermined duration, from the time of reception of each selection signal by the receiving module 50. The duration of the first time window is for example between 5 minutes and 24 hours.

[0073] Alternatively, update module 65 is configured to, if the support number indicator is the support frequency estimator, update, for each unit area 80, an average time between two successive selections of the same unit area 80. This calculation being carried out for example on a second sliding time window of a duration for example between 10 minutes and 24 hours.

[0074] Alternatively, the update module 65 is configured to convert the number of taps indicator of each unit surface 80 into a number of taps indicator specific to each cell of the page displayed by the touch screen 20. Thus, each displayed cell covering one or more unit surfaces 80, the update module 65 is configured to determine, for each cell of the displayed page, the number of taps indicator of the cell by taking an average of the number of taps indicators of each unit surface 80 covered by the cell.

[0075] The estimation module 70 is configured to estimate a contamination indicator for at least one predetermined contaminant based on the number of contacts for each unit surface 80 and / or each cell of the displayed content. To this end, the estimation module 70 is configured to apply a predefined model to the number of contacts for all unit surfaces 80. Thus, the contamination indicator is either associated with each unit surface 80 or with each cell of the content to be displayed. In the latter case, since the number of contacts for each cell of the content to be displayed is calculated from the number of contacts for each unit surface 80 covered by that cell, the contamination indicator is also associated with at least one unit surface 80.

[0076] The model is configured to produce, for example, for each unit area 80, a contamination indicator that is proportional to, and for example equal to, the indicator of the number of associated supports. Advantageously, with such a model, for each unit area 80, the higher the indicator of the number of supports, the higher the contamination indicator, and vice versa.

[0077] Alternatively, the model simultaneously takes into account the number of supports indicator of all or part of the unit surfaces 80 and produces a contamination indicator for each unit surface 80 taken into account, from the corresponding indicators.

[0078] Alternatively, the model is configured to provide a contamination indicator for each cell of the content displayed by the 20-inch touchscreen.

[0079] Alternatively, the model also takes into account physical parameters of contaminant diffusion or concentration on the touchscreen 20. For example, the model considers the predefined tilt of the touchscreen 20, or temperature data supplied to the electronic control system 35, via the receiving module 50, from a temperature sensor (not shown). Advantageously, in this variant, the contamination indicator calculated by the model is specifically designed to account for the movement of contaminants along the touchscreen 20, this movement being influenced, for example, by temperature.

[0080] Alternatively, the model can provide multiple contamination indicators, each specific to a predefined contaminant. To this end, the model includes a corresponding sub-model for each contaminant. In other words, when the model is applied to the number of pressure points, each contaminant's respective sub-model is then applied to the pressure point indicators.

[0081] Thus, considering different physical, chemical and / or biological properties for each contaminant, the corresponding contamination indicator is then advantageously different from another.

[0082] As an example, the model is, for each unit surface 80 and for at least one contaminant of the form: C t = C t − 1 + C d é p o s é e − C p r é l e v é e I appui t + α − β Or : C ( t ) is the contamination indicator at a given time t ; C ( t - 1) is the contamination indicator at a given timet - 1; C déposée is an indicator of the amount of contaminant deposited on the touch screen 20 by a press, this indicator being predefined for each contaminant; C prélevée is an indicator of the amount of contaminant taken from the touch screen 20 by a press, this indicator being predefined for each contaminant; I appui ( t ) is the indicator of the number of contacts detected on the unit surface 80 between the instant t - 1 and t ; α is a coefficient of growth or decrease of the contamination indicator due to the presence of contaminant on the unit surface considered or on the cell considered, this coefficient being, for example, predefined for each contaminant or dependent on quantities including: the contaminant indicator at time t - 1, the temperature, the screen tilt 20; and βis a destruction coefficient estimating the amount of contaminant destroyed during cleaning; the destruction coefficient is, for example, predefined.

[0083] The learning module 73 is configured to receive, from an operator or an unrepresented remote database, a set of labeled training data specific to a contaminant. The term "labeled data" here refers to a pair of input and output data, in which the input data includes a number-of-press indicator and / or parameters related to the installation and its environment (temperature, touchscreen tilt 20), and the output data includes at least one contamination indicator.

[0084] Thus, the learning module 73 is configured to perform machine learning (from English machine learning ) of the model from the labeled data. In other words, the learning module 73 is configured to generate a model or correct the existing model(s) from the labeled data, and by applying a machine learning algorithm.

[0085] The 75 emission module is configured to emit an alert signal if one or more contamination indicators exceed a threshold. The threshold is advantageously predetermined.

[0086] In the example where the model is configured to produce, for each unit area 80, several respective contamination indicators for different contaminants considered, the emission module 75 is configured to compare each contamination indicator to a respective threshold. All thresholds are, for example, equal to each other.

[0087] The alert signal is, for example, a message intended to warn an operator or user 15 that a cleaning of the touch screen 20 is required.

[0088] The 75 transmission module is then configured to transmit this message via wired or wireless communication to a monitoring center. The monitoring center is, for example, located in the train station.

[0089] Alternatively, the alert signal is a control signal for the human-machine interface display. In this case, the transmitting module 75 is configured to send the alert signal to the acquisition / transmitting module 40 to command a shift in a predetermined direction and distance from the displayed content.

[0090] The distance is, for example, equal to 1cm.

[0091] Alternatively, the distance is defined as a percentage of the extent of a unit area 80 along the offset direction.

[0092] The distance is advantageously greater than 100 percent of the extent of a unit area along the direction of offset, so that each point of a selection on the touch screen no longer corresponds to a press in the same unit area as before the offset.

[0093] In the example where each unit surface 80 is rectangular, the offset direction is, for example, parallel to one side of a unit surface 80 and at a distance greater than a length of that side. The direction is, for example, horizontal.

[0094] In the example of the figure 1 , the electronic service device 25 is for example a programmable electronic device, comprising an electronic memory 85 and a processor 90 associated with the electronic memory.

[0095] In one embodiment, the electronic processing system 30 and the electronic control system 35 are each implemented as software. In particular, each of the receiving module 50, determining module 55, detecting module 60, updating module 65, estimating module 70, learning module 73, and transmitting module 75 is implemented as a software module comprising software instructions executable by the processor 90. The memory 85 of the electronic service device is then capable of storing these software modules, which form a computer program that, when executed by a computer, implements a contamination control process as described.

[0096] This computer program is also capable of being stored on a computer-readable medium, not shown here. A computer-readable medium is, for example, a medium capable of storing electronic instructions and being connected to a bus of a computer system. Examples of such a readable medium include an optical disc, a magneto-optical disc, ROM, RAM, any type of non-volatile memory (e.g., EPROM, EEPROM, Flash, N-VRAM), a magnetic card, or an optical card. A computer program containing software instructions is then stored on this readable medium.

[0097] In an alternative not shown, the determination module 55, the detection module 60, the update module 65, the estimation module 70, the learning module 73, the transmission module 75, and optionally the reception module 50, the acquisition / transmission module 40, and the processing module 45 are each implemented as a programmable logic component, such as an FPGA (from the English Field Programmable Gate Array ), or even an integrated circuit such as an ASIC (from the English Application-Specific Integrated Circuit).

[0098] The operation of the electronic service device 25, and in particular of the electronic control system 35 according to the invention, will now be described with regard to the figure 3 representing a flowchart of the process, according to the invention, of controlling a quantity of contaminant, the process being implemented by the electronic control system 35.

[0099] The operation of system 35 is first described in a nominal case where only one contaminant is considered.

[0100] Before the system can operate, the learning module 73 receives a set of labeled data from the database. The learning module 73 then generates a model and / or corrects the existing model(s) within the control system 35 using automatic machine learning based on the labeled data. Thus, at the end of this learning process, the model(s) are up-to-date with respect to the received labeled data.

[0101] During a determination step 100, the electronic control system 35 determines at least one unit surface on the touch screen 20. For this purpose, the determination module 55 determines a tiling of unit surfaces 80 filling the touch screen 20.

[0102] The determination step 100 is carried out for example at the time of setting up the installation 10, or at the time of integrating the electronic control system 35 into the installation 10.

[0103] Then, the electronic service device 25 generates the first content and displays it via the touch screen 20. The user 15, wishing to take advantage of the installation 10, presses the touch screen 20.

[0104] Upon this press, the sensors of the touchscreen 20 determine the coordinate(s) of the point(s) selected by the user. These coordinates are included in a selection signal emitted by the sensors towards the electronic control system 35.

[0105] During a detection step 110, the detection module 60 detects the unit surface(s) 80 that have been supported by the user 15.

[0106] Detection step 110 includes, for example, the following sub-steps.

[0107] During a reception sub-step 112, the receiving module 50 receives the selection signal from the touch screen 20.

[0108] During an optional generation substep 114, the detection module 60 generates a first z 1 or a second z 2 peripheral surface according to the second or fourth detection mode, depending on the number of points whose coordinates are included in the selection signal.

[0109] During an identification substep 118, if the selection signal includes the coordinates x0, y0 of a single point, the detection module 60 identifies the unit surface(s) 80 that have been touched by the user 15, according to the first or second detection mode. The terms "detect" and "identify" are used here synonymously.

[0110] During the identification substep 118, if the selection signal includes the coordinates x0, y0, x1, Y1, x2, y2 of a plurality of points, the detection module 60 detects the unit surface(s) 80 that have been touched by the user 15, according to the third or fourth detection mode.

[0111] During an update step 120, the update module 65 updates the support number indicator for each unit surface 80.

[0112] For this purpose, if the support number indicator for each unit surface 80 is a support number counter, the update module 65 increments the counter for each unit surface 80 detected during the detection step 110.

[0113] Alternatively, if the support number indicator for each unit surface 80 is a support frequency estimator, the update module 65 updates the number of supports in the first sliding window by incrementing the support frequency of each detected unit surface 80 and counting the supports experienced by each surface 80 prior to the start of the first sliding window.

[0114] Alternatively, if the support count indicator for each unit surface 80 is a support frequency estimator, update module 65 updates the average time between two supports for each unit surface 80. To do this, update module 65 calculates the average time between two supports for each unit surface 80 based on the reception times of each support received in the second sliding window.

[0115] During an estimation step 130, the estimation module 70 estimates the contamination indicator of each unit surface 80. To this end, the estimation module 70 applies the predefined model to the support number indicators of the unit surfaces 80. The predefined model then provides, for each unit surface 80, the contamination indicator.

[0116] During a comparison step 140, the estimation module 70 compares the contamination indicator of each unit surface 80 to a predefined threshold.

[0117] If the contamination indicator of each of the unit surfaces 80 is below the threshold, then the control process returns to the detection step 110.

[0118] On the other hand, if the contamination indicator of at least one unit surface 80 is greater than or equal to the predefined threshold, then the process moves to an emission step 150.

[0119] During emission step 150, the emission module 75 emits the warning signal.

[0120] If the alert signal is a message intended to warn an operator, then the transmission module 75 emits this signal towards a connected device not shown.

[0121] If the alert signal is a message intended to warn user 15, then the transmitting module 75 sends this signal towards the acquisition / sending module 40. The processing module 45 then generates new content including a text or pictorial message indicating, when displayed by the touch screen 20, to user 15 that cleaning is required.

[0122] If the alert signal is a command signal for a shift in the display of the content, then the transmitting module sends this signal towards the electronic processing system 30. After the alert signal is transmitted, the process returns to the detection step 110. In the example where the alert signal is a command signal, the processing module 30 then generates new content comprising the elements of the first content but shifted horizontally by the predetermined distance.

[0123] The person in the trade will notice that the offset of the content to be displayed avoids the concentration of pressure on one or more of the same unit surfaces 80. Thus the risk of contamination is reduced.

[0124] Alternatively, during the comparison step 140, the estimation module 70 compares the contamination indicator of each unit surface 80 to a first s1 and a second s2 thresholds. The second threshold is higher than the first threshold.

[0125] If the contamination indicator of at least one of the unit surfaces 80 is greater than the first threshold, then, during the emission step 150, the alert signal emitted is the control signal.

[0126] If the contamination indicator of at least one of the unit surfaces 80 is greater than or equal to the second threshold, then, during the emission stage, the alert signal issued is a message indicating that cleaning of the touch screen is required.

[0127] There figure 4 illustrates this variant. More specifically, the figure 4 shows the temporal evolution of a contamination indicator of a respective unit surface 80.

[0128] At times t1, t2, and t3, the contamination indicator exceeds the first threshold s1. Consequently, the control signal is emitted during transmission step 150, leading to a shift in the content display. Following this shift, the contamination indicator decreases.

[0129] However, the display shift at time t3 is not sufficient to decrease the contamination indicator. Such a situation is characteristic, for example, of heavy use of installation 10. Then, at time t4, the contamination indicator reaches the second threshold s2, and the transmission module 75 then emits the alert message during transmission step 150. This leads to a cleaning of the touchscreen, reducing the contamination indicator to approximately zero.

[0130] Alternatively, several contaminants are considered. According to this alternative, the determination 100, detection 110, and update 120 steps are analogous to the nominal operation described above. However, during the estimation step, the model provides, for each unit area 80, a contamination indicator for each contaminant considered. Consequently, the estimation 140 step, and the emission step 150 if applicable, are performed for each contaminant considered based on the contamination indicators and the associated threshold.

[0131] According to one embodiment, the electronic control system 35 is partially remote from the installation 10. In particular, the receive module 50 and transmit module 75 are integrated into the installation as communication relays, while the determination module 55, detection module 60, update module 65, estimation module 70, and learning module 73 are located on a remote server. Thus, according to this embodiment, the receive module 50 and transmit module 75 act as relays between the electronic processing system 30 and the touchscreen 20 on the one hand, and the server on the other.

[0132] It is then understood that in this variant of the embodiment, the receiving module 50 is configured to transmit to the server all the data received from the processing system 30 and the plurality of sensors of the touch screen 20. The transmitting module 75 is configured to emit the alert signal following an instruction from the server.

[0133] Thus, advantageously, the method and system according to the invention make it possible to control the quantity of contaminant present on the touch screen in a simpler way.

[0134] Furthermore, advantageously, it does not require the implementation of new sensors within the installation. Thus, the system and method according to the invention are more easily implemented within an already existing installation.

Claims

1. A method for checking a touch screen (20) of an installation (10) for contamination by at least one contaminant, the touch screen (20) being suitable for receiving commands from user(s) (15) by finger pressure, the method being implemented by an electronic control system (35) and being characterized in that it comprises the following steps: - determining (100) at least one unit surface area (80) on the touch screen (20), the touch screen (20) comprising at least two unit surface areas (80), - detecting (110) the unit surface area(s) (80) having been pressed by a user (15), - updating (120) an indicator of the number of presses per unit surface area (80), - estimating (130) at least one contamination indicator by at least one predetermined contaminant, based on the indicators of number of presses associated with each unit surface area (80), the contamination indicator being associated with at least one of the unit surface areas (80), and - if the or at least one of the contamination indicators reaches or exceeds a threshold, emitting (150) an alert signal during the estimating step (130), a predefined model being applied to the or at least one of the number of press indicators, the model producing the at least one contamination indicator, the predefined model depending on physical parameters of diffusion and / or concentration of the contaminant on the touch screen (20), the model taking account of the incline of the touch screen (20), in a predefined manner.

2. The method according to claim 1, wherein the model further takes into account temperature data.

3. The method according to claim 1 or 2, wherein the installation (10) is chosen from a group consisting of: - a transportation ticket vending machine, - a parking ticket vending machine, and - an audiovisual system embedded in a vehicle.

4. The method according to any one of claims 1 to 3, wherein during the transmission step (150), the alert signal comprises a message intended to warn an operator or a user that cleaning of the touch screen (20) is required.

5. The method according to any one of claims 1 to 4, wherein the touch screen (20) is capable of displaying selectable content, and wherein during the transmission step (150), the alert signal comprises a signal for controlling a display shift of the selectable content.

6. The method according to claim 5, wherein the control signal is a control signal for a horizontal shift in the display of the content.

7. The method according to any one of claims 1 to 6, wherein during the determining step (100), the unit surface areas define a tiling filling the touch screen (20).

8. The method according to any one of [claims] 1 to 7, wherein the detecting step (110) comprises, for each press, the following sub-steps: - receiving (112) coordinates corresponding to a set of pressing point(s) on the touch screen (20), and - identifying (118) at least one unit surface area (80) having undergone the pressing from the coordinates received.

9. The method according to claim 8, wherein the detecting step (110) comprises, between the receiving sub-step (112) and the identifying sub-step (118), a determining sub-step (114) for determining a peripheral zone (z1; z2) including the pressing point(s).

10. A computer program comprising software instructions which, when executed by a computer or a processor, implement a method for checking contamination by at least one contaminant according to any one of claims 1 to 9.

11. An electronic system (35) for checking a touch screen (20) of an installation (10) for contamination by at least one contaminant, the touch screen (20) being suitable for receiving commands from user(s) (15) by finger pressure, the electronic checking system (35) being characterized in that it comprises: - a determining module (55) configured to determine at least one unit surface area (80) on the touch screen (20), the touch screen (20) comprising at least two unit surface areas (80), - a detecting module (60), configured to detect the unit surface area(s) (80) that have been pressed by a user (15), - an updating module (65) configured to update an indicator of number of presses per unit surface area (80), - an estimating module (70) configured to estimate at least one contamination indicator by at least one predetermined contaminant, based on the indicators of the number of presses associated with each unit surface area (80), the contamination indicator being associated with at least one of the unit surface areas (80), and - an emitting module (70) configured, if the or at least one of the contamination indicators reaches or exceeds a threshold, to emit an alert signal, the estimating module (70) further being configured to apply a predefined model to the or at least one of the number of presses indicators, the model producing the at least one contamination indicator, the predefined model depending on physical parameters of diffusion and / or concentration of the contaminant on the touch screen (20), the model taking account of the incline of the touch screen (20), in a predefined manner.